Invention name: Structural polyurethane adhesive
Technical field
[0001]
The present invention relates to a structural polyurethane adhesive.
Background technology
[0002]
Conventionally, in a structure composed of a plurality of members (for example, an automobile, a building, etc.), a structural adhesive used for adhering each of these members is known.
[0003]
Examples of the structural adhesive include a urethane prepolymer (A-1) obtained by reacting polyoxypropylene diol, polyoxypropylene triol and 4,4'diisocyanate phenylmethane, and an isocyanurate form of pentamethylene diisocyanate (isocyanurate). A two-component urethane-based adhesive composition containing a main agent containing C1-2) and a curing agent containing fine particles (D-5) composed of a trifunctional polypropylene polyol (B1-1) and a styrene homopolymer can be obtained. It has been proposed (see, for example, Patent Document 1 (Example 1)).
Prior art literature
Patent documents
[0004]
Patent Document 1: International Publication WO2016 / 080508
Outline of the invention
Problems to be solved by the invention
[0005]
On the other hand, the above-mentioned two-component urethane adhesive composition has a problem that the adhesive strength is not sufficient.
[0006]
The present invention is a structural polyurethane adhesive having excellent adhesive strength.
Means to solve problems
[0007]
The present invention [1] comprises a urethane prepolymer having an isocyanate group at the molecular end, a polyisocyanate component containing a derivative of xylylene diisocyanate, a number average molecular weight of 500 or more and 10000 or less, and an average number of hydroxyl groups of 1.9 or more and 4.0. It contains a structural polyurethane adhesive containing a polyol component including the following macropolyol.
[0008]
In the present invention [2], the polyisocyanate component contains a compatibilizer for compatibilizing the urethane prepolymer and the derivative of xylylene diisocyanate, and the solubility parameter of the compatibilizer determined by the Fedors formula. However, the structural polyurethane adhesive according to the above [1], which is 7.5 (cal / cm 3) 1/2 or more and 13.0 (cal / cm 3) 1/2 or less, is contained.
[0009]
The present invention [3] is the above-mentioned [2], wherein the compatibilizer is at least one plasticizer selected from the group consisting of phthalates, adipates, benzoic acids and hydrogenated phthalates. Contains the structural polyurethane adhesives described in.
[0010]
In the present invention [4], the structural polyurethane adhesive according to any one of the above [1] to [3], wherein the derivative of xylylene diisocyanate contains an isocyanurate derivative of xylylene diisocyanate. ..
[0011]
The above [1] to [4], wherein the content of the derivative of the xylylene diisocyanate of the present invention [5] is 1.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the total amount of the urethane prepolymer. Contains the structural polyurethane adhesive according to any one of the above.
[0012]
In the present invention [6], the structural polyurethane adhesive according to any one of the above [1] to [5], wherein the macropolyol contains a polyether polyol in the polyol component.
[0013]
In the present invention [6], the urethane prepolymer is a reaction product of a raw material polyisocyanate containing diphenylmethane diisocyanate and a raw material polyol containing a macropolyol, according to any one of the above [1] to [6]. Contains the described structural polyurethane adhesives.
[0014]
The present invention [8] is described in any one of the above [1] to [7], which is a two-component curable adhesive comprising a main agent composed of the polyisocyanate component and a curing agent composed of the polyol component. Contains structural polyurethane adhesives.
[0015]
The present invention [9] includes the structural polyurethane adhesive according to any one of the above [1] to [8], which is a solvent-free adhesive.
Effect of the invention
[0016]
In the structural polyurethane adhesive of the present invention, the polyisocyanate component contains a urethane prepolymer having an isocyanate group at the molecular terminal and a derivative of xylylene diisocyanate, and the polyol component has a number average molecular weight and an average number of hydroxyl groups. Since it contains a macropolypoly in a predetermined range, excellent adhesive strength can be obtained.
Mode for carrying out the invention
[0017]
The structural polyurethane adhesive of the present invention is a structural adhesive defined in JIS K 6800 (1985), and specifically, is a "reliable adhesive that can withstand a large load for a long period of time".
[0018]
More specifically, the structural polyurethane adhesive contains a polyisocyanate component, which is a component containing a free (free) isocyanate group, and a polyol component, which is a component containing a free (free) hydroxyl group, as essential components. Included as.
[0019]
The structural polyurethane adhesive may be a one-component curable adhesive in which a polyisocyanate component and a polyol component are mixed in advance, and a main agent (liquid A) composed of the polyisocyanate component and a polyol component may be used. It may be a two-component curing type adhesive which is provided with a curing agent (B liquid) composed of, and is mixed with a main agent and a curing agent individually prepared at the time of use.
[0020]
The structural polyurethane adhesive is preferably a two-component curable adhesive from the viewpoint of workability, handleability, and the like.
[0021]
The polyisocyanate component contains a urethane prepolymer having an isocyanate group at the molecular end (hereinafter referred to as an isocyanate group-terminated urethane prepolymer) and a derivative of xylylene diisocyanate.
[0022]
The isocyanate group-terminated urethane prepolymer is a urethane prepolymer having at least two isocyanate groups at the molecular ends, and is obtained by reacting the raw material polyisocyanate and the raw material polyol so that the isocyanate group is excessive with respect to the hydroxyl group. The resulting reaction product.
[0023]
Examples of the raw material polyisocyanate include polyisocyanate monomers and polyisocyanate derivatives.
[0024]
Examples of the polyisocyanate monomer include aromatic polyisocyanates, aromatic aliphatic polyisocyanates, and aliphatic polyisocyanates.
[0025]
Examples of the aromatic polyisocyanate include tolylene diisocyanate (2,4- or 2,6-toluene diisocyanate or a mixture thereof) (TDI), phenylenedi isocyanate (m-, p-phenylenediocyanate or a mixture thereof), 4, 4'-Diphenyldiisocyanate, 1,5-naphthalenediocyanate (NDI), diphenylmethane diisocyanate (4,4'-, 2,4'-or 2,2'-diphenylmethane diisocyanate or a mixture thereof) (MDI), Examples thereof include aromatic diisocyanates such as 4,4'-toluene diisocyanate (TODI) and 4,4'-diphenyl ether diisocyanate.
[0026]
Examples of the aromatic aliphatic polyisocyanate include xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or a mixture thereof) (XDI) and tetramethylxylylene diisocyanate (1,3- or 1,4-tetra). Examples thereof include methylxylylene diisocyanate (or a mixture thereof) (TMXDI), aromatic aliphatic diisocyanates such as ω, ω'-diisocyanate-1,4-diethylbenzene and the like.
[0027]
Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), and 1 , 5-Pentamethylene diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisamethylene methyl caproate, etc. Examples include aliphatic diisocyanate.
[0028]
In addition, the aliphatic polyisocyanate includes an alicyclic polyisocyanate. Examples of the alicyclic polyisocyanate include 1,3-cyclopentanediisocyanate, 1,3-cyclopentenediisocyanate, cyclohexanediisocyanate (1,4-cyclohexanediisocyanate, 1,3-cyclohexanediisocyanate), and 3-isocyanatomethyl-3. , 5,5-trimethylcyclohexylisocyanate (isoholodiisocyanate) (IPDI), methylenebis (cyclohexylisocyanate) (4,4'-, 2,4'-or 2,2'-methylenebis (cyclohexylisocyanate, Trans, Transs of these) -Form, Trans, Cis-form, Cis, Cis-form, or a mixture thereof)) (H 12MDI), methylcyclohexanediisocyanate (methyl-2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate), norbornandiisocyanate (Various isomers or mixtures thereof) (NBDI), bis (isocyanatomethyl) cyclohexane (1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or a mixture thereof) (H 6XDI) and other alicyclic diisocyanates Can be mentioned.
[0029]
These polyisocyanate monomers can be used alone or in combination of two or more.
[0030]
Examples of the polyisocyanate derivative include multimers of the above-mentioned polyisocyanate monomers (for example, dimer and trimeric (for example, isocyanurate derivative and iminooxadiazinedione derivative)), pentamer and heptameric. , Etc.), allophanate derivatives (for example, allophanate derivatives produced by the reaction of the above-mentioned polyisocyanate monomer with known monovalent alcohols (described later) and / or known divalent alcohols (described later)), polyol derivatives (for example) For example, a polyol derivative (alcohol adduct) produced by the reaction of a polyisocyanate monomer with a known trivalent or higher valent alcohol (described later), a biuret derivative (for example, the above-mentioned polyisocyanate monomer, water, etc.) Biuret derivatives produced by reaction with amines), urea derivatives (for example, urea derivatives produced by the reaction of the above-mentioned polyisocyanate monomer with diamine), oxadiazine trione derivatives (for example, the above-mentioned polyisocyanate). Examples include oxadiazine trione produced by the reaction of a monomer and carbon dioxide gas), a carbodiimide derivative (such as a carbodiimide derivative produced by the decarbonate condensation reaction of the polyisocyanate monomer described above), a uretdione derivative, and a uretonimine derivative. Be done.
[0031]
Further, examples of the polyisocyanate derivative include polymethylene polyphenyl polyisocyanate (crude MDI, polypeptide MDI, polynuclear compound-containing diphenylmethane diisocyanate) and the like.
[0032]
These polyisocyanate derivatives can be used alone or in combination of two or more.
[0033]
These raw material polyisocyanates can be used alone or in combination of two or more.
[0034]
From the viewpoint of adhesive strength, the raw material polyisocyanate preferably includes a polyisocyanate monomer, more preferably an aromatic polyisocyanate, further preferably a diphenylmethane diisocyanate, and particularly preferably 4 , 4'-diphenylmethane diisocyanate.
[0035]
Examples of the raw material polyol include macropolyol. The macropolyol has a number average molecular weight of 300 or more, preferably 40, having two or more hydroxyl groups.It is a compound of 0 or more, for example, 10000 or less.
[0036]
In the raw material polyol, the macropolyol is not particularly limited, and examples thereof include macropolyol, which will be described later, as a polyol component (curing agent). These macropolyols can be used alone or in combination of two or more.
[0037]
As the macropolyol as a raw material polyol, preferably, a polyether polyol (described later), a polyester polyol (described later), and a polycarbonate polyol (described later) can be mentioned, and more preferably, a polyether polyol (described later) can be mentioned, and even more preferably. , Polyoxy (C2-3) alkylene polyols.
[0038]
The number average molecular weight (polystyrene-equivalent molecular weight measured by the gel permeation chromatogram method) of the macropolyol as a raw material polyol is, for example, 300 or more, preferably 400 or more, more preferably 500 or more, for example, 10,000. Hereinafter, it is preferably 8000 or less, more preferably 5000 or less.
[0039]
The hydroxyl group equivalent of the raw material polyol is, for example, 150 or more, preferably 200 or more, and for example, 10,000 or less, preferably 8000 or less.
[0040]
The hydroxyl group equivalent can be calculated from the hydroxyl value obtained by obtaining the hydroxyl value from the acetylation method or the phthalation method based on the A method or the B method of JIS K 1557-1 (2007) (hereinafter,). Same.).
[0041]
The average number of hydroxyl groups of the macropolyol as a raw material polyol is, for example, 1.8 or more, preferably 2 or more, and for example, 6 or less, preferably 4 or less, and more preferably 3 or less.
[0042]
The average number of hydroxyl groups can be calculated from the hydroxyl value, the equivalent of hydroxyl groups and the molecular weight.
[0043]
The average number of hydroxyl groups can also be calculated from the charging ratio of the raw material components. In such a case, the number average molecular weight can be calculated from the hydroxyl group equivalent and the average number of hydroxyl groups (the same applies hereinafter).
[0044]
As the raw material polyol, a macropolyol having an average number of hydroxyl groups of 2 and a macropolyol having an average number of hydroxyl groups of 3 are particularly preferably used in combination.
[0045]
When a macropolypoly having an average number of hydroxyl groups of 2 and a macropolypoly having an average number of hydroxyl groups of 3 are used in combination, the amount of the macropolypoly having an average number of hydroxyl groups of 2 exceeds, for example, 50 parts by mass with respect to 100 parts by mass of the total amount thereof. It is preferably 60 parts by mass or more, for example, 90 parts by mass or less, preferably 80 parts by mass or less. The macropolyol having an average number of hydroxyl groups of 3 is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and for example, less than 50 parts by mass, preferably 40 parts by mass or less.
[0046]
Further, the raw material polyol can contain a low molecular weight polyol, if necessary.
[0047]
The low molecular weight polyol is a compound having two or more hydroxyl groups and having a number average molecular weight of less than 300, preferably less than 400, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, and the like. 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethyl Pentandiol, 3,3-dimethylolheptan, alcoholic (C7-20) diols, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,3- or 1,4-cyclohexanediol and theirs. Dihydric alcohols such as mixture, hydride bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octene-3,8-diol, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol , For example, trihydric alcohols such as glycerin, trimethylolpropane, triisopropanolamine, for example, tetrahydric alcohols such as tetramethylolmethane (pentaerythritol), diglycerin, for example, pentahydric alcohols such as xylitol, for example, sorbitol, mannitol. , Hexal alcohols such as alitol, igitol, darsitol, altritor, inositol, dipentaerythritol, for example, heptahydric alcohols such as persetol, for example, octahydric alcohols such as sucrose.
[0048]
These low molecular weight polyols can be used alone or in combination of two or more.
[0049]
The content ratio of the low molecular weight polyol to the raw material polyol is appropriately selected as long as the excellent effect of the present invention is not impaired.
[0050]
More specifically, the content ratio of the low molecular weight polyol is, for example, 30 parts by mass or less, preferably 20 parts by mass or less, and more preferably 10 parts by mass or less with respect to 100 parts by mass of the total amount of the raw material polyol. , Particularly preferably 0 parts by mass.
[0051]
That is, from the viewpoint of adhesive strength, the raw material polyol preferably does not contain a low molecular weight polyol and is composed of a macropolyol.
[0052]
The isocyanate group-terminated urethane prepolymer is such that the ratio of the raw material polyisocyanate and the raw material polyol to the equivalent ratio (NCO / OH) of the isocyanate group of the raw material polyisocyanate to the hydroxyl group of the raw material polyol is larger than 1, preferably. It can be obtained by carrying out a urethanization reaction at a ratio of 1.3 to 50, more preferably 1.5 to 3.
[0053]
The urethanization reaction can be based on a known method. The reaction temperature in the urethanization reaction is, for example, 50 ° C. or higher, for example, 120 ° C. or lower, preferably 100 ° C. or lower. The reaction time is, for example, 0.5 hours or more, preferably 1 hour or more, and for example, 24 hours or less, preferably 15 hours or less.
[0054]
Further, the urethanization reaction may be a reaction in the absence of a solvent or a reaction in the presence of an organic solvent (solution polymerization).
[0055]
Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, nitriles such as acetonitrile, and alkyl esters such as methyl acetate, ethyl acetate, butyl acetate and isobutyl acetate, for example, n-. Aliper hydrocarbons such as hexane, n-heptane, octane, eg, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, eg aromatic hydrocarbons such as toluene, xylene, ethylbenzene, eg, methylcellosolve acetate. , Ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate and other glycol ether esters. Such as ethers such as diethyl ether, tetrahydrofuran, dioxane, for example, halogenated aliphatic hydrocarbons such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, dichloroethane, for example. Polar aprotons such as N-methylpyrrolidone, dimethylformamide, N, N'-dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, and known non-flammable solvents can be mentioned.
[0056]
These organic solvents can be used alone or in combination of two or more.
[0057]
In solution polymerization, the blending ratio of the organic solvent is appropriately set depending on the purpose and application.
[0058]
Further, in the urethanization reaction, for example, a known urethanization catalyst such as amines or an organometallic compound can be added at an appropriate ratio, if necessary.
[0059]
Examples of amines include tertiary amines such as triethylamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether, and N-methylmorpholine, and quaternary ammonium salts such as tetraethylhydroxylammonium, for example, imidazole. Examples thereof include imidazoles such as 2-ethyl-4-methylimidazole.
[0060]
Examples of the organic metal compound include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dilaurate, and dibutyltin. Organic tin compounds such as dineodecanoate, dioctyltin dimercaptide, dioctyltin dilaurylate, dibutyltin dichloride, eg organic lead compounds such as lead octanate, lead naphthenate, eg organic nickel compounds such as nickel naphthenate, eg , Organic cobalt compounds such as cobalt naphthenate, for example, organic copper compounds such as copper octene, for example, organic bismuth compounds such as bismuth octylate and bismuth neodecanoate.
[0061]
Further, examples of the urethanization catalyst include potassium salts such as potassium carbonate, potassium acetate, and potassium octylate.
[0062]
These urethanization catalysts can be used alone or in combination of two or more.
[0063]
The urethanization catalyst is preferably an organometallic compound.
[0064]
Further, when the isocyanate group-terminated urethane prepolymer is prepared in the presence of an organic solvent, the organic solvent can be removed by a known removing means, if necessary.
[0065]
Further, if necessary, the free (unreacted) raw material polyisocyanate from the obtained isocyanate group-terminated urethane prepolymer may be removed by a known removing means such as distillation or extraction.
[0066]
The average number of isocyanate groups of the isocyanate group-terminated urethane prepolymer (solid content) is, for example, 1.2 or more, preferably 1.5 or more, more preferably 2 or more, and for example, 4 or less, preferably 3 or less. Is.
[0067]
The isocyanate group-terminated urethane prepolymer (solid content) has an isocyanate group equivalent of, for example, 84 or more, preferably 150 or more, more preferably 168 or more, and for example, 3500 or less, preferably 2800 or less, still more preferably. , 2335 or less. The isocyanate group equivalent is synonymous with the amine equivalent, and can be determined by the method A or method B of JIS K 1603-1 (2007).
[0068]
The isocyanate group content (isocyanate group content, NCO%) of the isocyanate group-terminated urethane prepolymer (solid content) is, for example, 1.2% by mass or more, preferably 1.5% by mass or more, more preferably. 1.8% by mass or more, more preferably 2.0% by mass or more, particularly preferably 3.0% by mass or more, for example, 50% by mass or less, preferably 28% by mass or less, more preferably. , 25% by mass or less, more preferably 10% by mass or less, and particularly preferably 6% by mass or less.
[0069]
The isocyanate group-terminated urethane prepolymer can be used alone or in combination of two or more.
[0070]
The isocyanate group-terminated urethane prepolymer is preferably an isocyanate group-terminated urethane prepolymer which is a reaction product of an aromatic polyisocyanate and a polyether polyol, and more preferably a reaction formation of a diphenylmethane diisocyanate and a polyether polyol. Examples thereof include isocyanate group-terminated urethane prepolymers.
[0071]
In the polyisocyanate component, the derivative of xylylene diisocyanate is a monomer (monomer) of xylylene diisocyanate.) Can be obtained by denaturing (derivatizing) by a known method.
[0072]
As the xylylene diisocyanate (XDI), 1,2-xylylene diisocyanate (o-XDI), 1,3-xylylene diisocyanate (m-XDI), and 1,4-xylylene diisocyanate (p-XDI) have a structure. Listed as an isomer.
[0073]
These xylylene diisocyanates can be used alone or in combination of two or more. Examples of the xylylene diisocyanate include 1,3-xylylene diisocyanate and 1,4-xylylene diisocyanate, and more preferably 1,3-xylylene diisocyanate.
[0074]
More specifically, as a derivative of xylylene diisocyanate, for example, a multimer of xylylene diisocyanate (for example, a dimer or a trimeric (for example, an isocyanurate derivative, an iminooxadiazidinedione derivative), a pentamer, etc. Hexanates, etc.), allophanate derivatives (eg, allophanate derivatives produced by the reaction of xylylene diisocyanate with known monovalent alcohols and / or known divalent alcohols), polyol derivatives (eg, xylylene diisocyanates). Polyol derivatives (alcohol adducts) produced by reaction with trivalent or higher valent alcohols), biuret derivatives (for example, biuret derivatives produced by reaction of xylylene diisocyanate with water or amines), urea derivatives (eg For example, a urea derivative produced by the reaction of xylylene diisocyanate with a diamine), an oxadiazine trione derivative (for example, an oxadiazine trione produced by a reaction of a xylylene diisocyanate with carbon dioxide), a carbodiimide derivative (xylylene diisocyanate). Carbodiimide derivatives produced by the decarbonate condensation reaction of isocyanates), uretdione derivatives, uretonimine derivatives and the like.
[0075]
These xylylene diisocyanate derivatives can be used alone or in combination of two or more.
[0076]
From the viewpoint of adhesive strength, the xylylene diisocyanate derivative is preferably an isocyanurate derivative of xylylene diisocyanate, an allophanate derivative of xylylene diisocyanate, a biuret derivative of xylylene diisocyanate, or a polyol derivative (alcohol adduct) of xylylene diisocyanate. Can be mentioned.
[0077]
More specifically, an isocyanurate derivative of xylylene diisocyanate can be obtained by subjecting xylylene diisocyanate to an isocyanurate-forming reaction in the presence of a known isocyanurate-forming catalyst. The reaction conditions in the isocyanurate-forming reaction are not particularly limited, and known methods can be applied.
[0078]
Further, the isocyanurate derivative of xylylene diisocyanate can be modified (alcohol-modified) with a monohydric alcohol and / or a known divalent alcohol, if necessary.
[0079]
Examples of the monohydric alcohol include linear monohydric alcohols of C (carbon number, the same applies hereinafter) 2 to 6 such as ethanol, n-propanol, n-butanol, n-pentanol, and n-hexanol, for example. Examples thereof include C3 to 6 branched monohydric alcohols such as isopropanol, isobutanol (isobutyl alcohol), sec-butanol, tert-butanol, isopentanol and isohexanol. These monohydric alcohols can be used alone or in combination of two or more.
[0080]
Examples of the dihydric alcohol include C2 to 6 linear divalents such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Alcohols such as 1,2-propanediol, 1,3-butanediol, 1,2-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol and other C3-6 branched divalents. Alcohol and the like can be mentioned. These dihydric alcohols can be used alone or in combination of two or more.
[0081]
The modification method with monohydric alcohol and / or dihydric alcohol is not particularly limited, and for example, xylylene diisocyanate and alcohols are urethanized, and then isocyanurate-ized in the presence of an isocyanurate-forming catalyst. Therefore, an isocyanurate derivative of alcohol-modified xylylene diisocyanate can be obtained.
[0082]
In the alcohol modification of the xylylene diisocyanate derivative, the reaction conditions and the formulation (alcohol modification amount) are appropriately set according to the purpose and application.
[0083]
The allophanate derivative of xylylene diisocyanate is obtained by, for example, subjecting xylylene diisocyanate to a urethanization reaction of the above monohydric alcohol and / or dihydric alcohol, and then further performing an allophanization reaction in the presence of a known allophanization catalyst. ,Obtainable.
[0084]
The reaction conditions in the allophanate reaction of xylylene diisocyanate are not particularly limited, and known methods can be applied.
[0085]
A polyol derivative (alcohol adduct) of xylylene diisocyanate can be obtained, for example, by reacting xylylene diisocyanate with a known trivalent or higher valent alcohol at a ratio of excess isocyanate group to a hydroxyl group. can.
[0086]
Examples of trihydric or higher alcohols include trihydric alcohols such as glycerin, trimethylolpropane, and triisopropanolamine. These trihydric or higher alcohols can be used alone or in combination of two or more. Examples of the trihydric or higher alcohol preferably include a trihydric alcohol, and more preferably trimethylolpropane.
[0087]
The reaction conditions between xylylene diisocyanate and a trihydric or higher alcohol are not particularly limited, and a known method can be applied.
[0088]
The biuret derivative of xylylene diisocyanate reacts, for example, xylylene diisocyanate with water, a tertiary alcohol (eg, t-butyl alcohol, etc.), a secondary amine (eg, dimethylamine, diethylamine, etc.), and the like. After that, it can be obtained by further biuretizing reaction in the presence of a known biuretizing catalyst.
[0089]
The reaction conditions in the biuretization reaction of xylylene diisocyanate are not particularly limited, and a known method can be applied.
[0090]
Examples of these xylylene diisocyanate derivatives include isocyanurate derivatives of xylylene diisocyanate, allophanate derivatives of xylylene diisocyanate, and biuret derivatives of xylylene diisocyanate, and particularly preferably xylylene diisocyanate, from the viewpoint of adhesive strength. Isocyanurate derivatives of.
[0091]
In other words, the derivative of xylylene diisocyanate preferably contains an isocyanurate derivative of xylylene diisocyanate.
[0092]
Further, when the isocyanurate derivative of xylylene diisocyanate is alcohol-modified, the allophanate derivative of xylylene diisocyanate may be obtained as a by-product. That is, when the isocyanurate derivative of xylylene diisocyanate is alcohol-modified, the derivative of xylylene diisocyanate contains an allophanate derivative of xylylene diisocyanate as a by-product together with the isocyanurate derivative of xylylene diisocyanate in an appropriate ratio. Can be included in.
[0093]
In such a case, the ratio (molar ratio) of the isocyanurate group to the allophanate group contained in the derivative (total amount) of xylylene diisocyanate is such that the isocyanurate group is based on the total mole of the isocyanurate group and the allophanate group. For example, 10 mol% or more, preferably 30 mol% or more, more preferably 50 mol% or more, still more preferably more than 50 mol%, still more preferably 70 mol% or more, still more preferably 90 mol%. The above is usually less than 100 mol%. Further, the allophanate group exceeds, for example, 0 mol%, for example, 90 mol% or less, preferably 70 mol% or less, more preferably 50 mol% or less, still more preferably less than 50 mol%, still more preferable. Is 30 mol% or less, more preferably 10 mol% or less.
[0094]
The ratio (molar ratio) of the isocyanurate group to the allophanate group is a known method based on, for example, the ratio of the peak height derived from the isocyanurate group measured by 1H-NMR to the peak height derived from the allophanate group. Can be calculated by
[0095]
Further, such a derivative of xylylene diisocyanate can also be prepared by, for example, mixing an isocyanurate derivative of xylylene diisocyanate and an allophanate derivative of xylylene diisocyanate prepared individually.
[0096]
In such a case, the mixing ratio of the isocyanurate derivative of xylylene diisocyanate is, for example, 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass, based on the total amount of the xylylene diisocyanate derivative. % Or more, more preferably more than 50% by mass, still more preferably 70% by mass or more, still more preferably 90% by mass or more.
[0097]
Further, the mixing ratio of the allophanate derivative of xylylene diisocyanate exceeds, for example, 0% by mass, for example, 90% by mass or less, preferably 70% by mass or less, more preferably with respect to the total amount of the xylylene diisocyanate derivative. Is 50% by mass or less, more preferably less than 50% by mass, still more preferably 30% by mass or less, still more preferably 10% by mass or less.
[0098]
Further, the derivative of xylylene diisocyanate may be prepared in the absence of a solvent, or may be prepared in the presence of an organic solvent.
[0099]
When the derivative of xylylene diisocyanate is prepared in the presence of an organic solvent, the organic solvent can be removed by a known removing means, if necessary.
[0100]
Further, if necessary, the free (unreacted) xylylene diisocyanate (monomer) from the obtained derivative of xylylene diisocyanate may be removed by a known removing means such as distillation or extraction.
[0101]
The average number of isocyanate groups of the xylylene diisocyanate derivative (solid content) is, for example, 1.2 or more, preferably 1.5 or more, more preferably 2 or more, and for example, 4 or less, preferably 3 or less. be.
[0102]
The isocyanate group equivalent of the xylylene diisocyanate derivative (solid content) is, for example, 84 or more, preferably 150 or more, more preferably 168 or more, and for example, 1000 or less, preferably 800 or less, still more preferably. It is 500 or less. The isocyanate group equivalent is synonymous with the amine equivalent, and can be determined by the method A or method B of JIS K 1603-1 (2007).
[0103]
The isocyanate group content (isocyanate group content, NCO%) of the xylylene diisocyanate derivative (solid content) is, for example, 15% by mass or more, preferably 16% by mass or more, and for example, 50% by mass or less. It is preferably 22% by mass or less, and more preferably 21% by mass or less.
[0104]
In the polyisocyanate component, the content ratio of the isocyanate group-terminated urethane prepolymer and the xylylene diisocyanate derivative is , The isocyanate group equivalent, the isocyanate group content, and the like are appropriately set.
[0105]
More specifically, from the viewpoint of adhesive strength, the isocyanate group-terminated urethane prepolymer is, for example, 70% by mass or more, preferably 70% by mass or more, based on the total mass of the isocyanate group-terminated urethane prepolymer and the derivative of xylylene diisocyanate. It is 80% by mass or more, more preferably 90% by mass or more, for example, 99% by mass or less, preferably 98% by mass or less, and more preferably 97% by mass or less. The derivative of xylylene diisocyanate is, for example, 1% by mass or more, preferably 2% by mass or more, more preferably 3% by mass or more, and for example, 30% by mass or less, preferably 20% by mass or less. More preferably, it is 10% by mass or less.
[0106]
Further, from the viewpoint of adhesive strength, the derivative of xylylene diisocyanate is, for example, 1.0 part by mass or more, preferably 1.5 parts by mass or more, based on 100 parts by mass of the total amount of the isocyanate group-terminated urethane prepolymer. It is preferably 3.0 parts by mass or more, for example, 40 parts by mass or less, preferably 30 parts by mass or less, and more preferably 20 parts by mass or less.
[0107]
Further, the polyisocyanate component can include a compatibilizer as an optional component.
[0108]
Preferably, the polyisocyanate component contains a compatibilizer.
[0109]
The compatibilizer is an additive for suppressing the phase separation between the isocyanate group-terminated urethane prepolymer and the derivative of xylylene diisocyanate and making them compatible.
[0110]
In the present invention, the compatibilizer has a solubility parameter (SP value) obtained by the Fedors formula of 7.5 (cal / cm 3) 1/2 or more and 13.0 (cal / cm 3) 1/2 or less. Defined to be a compound.
[0111]
The Fedors formula is a calculation formula for calculating the SP value from the cohesive energy density, molar volume (molar volume), and the like. F. Fedors, "A Method for Estimating Body The Solubility Parameters and Molar Volumes of Liquids" (POLYMER ENGINEERING AND SCIENCE, published in February 14, 1974, No. 2 1974, published in February 1974.
[0112]
That is, the SP value calculated by the Fedors formula is a calculated value determined by the molecular structure of the compound.
[0113]
In the present invention, a compound having an SP value of 7.5 (cal / cm 3) 1/2 or more and 13.0 (cal / cm 3) 1/2 or less calculated by the Fedors formula is used as a compatibilizer. can do.
[0114]
More specific examples of the compatibilizer include plasticizers, and examples of the plasticizer include carboxylic acid ester-based plasticizers such as phthalates, adipates, benzoates, and hydrogenated phthalates. Can be mentioned.
[0115]
Examples of the phthalate ester include dimethyl phthalate (DMP, SP value 11.54 (cal / cm 3) 1/2) and diethyl phthalate (DEP, SP value 11.07 (cal / cm 3) 1/2). ), Dibutyl phthalate (SP value 10.47 (cal / cm 3) 1/2), diheptyl phthalate (SP value 9.96 (cal / cm 3) 1/2), din-octyl phthalate (SP value 9.85 (cal / cm 3) 1/2), diisooctyl phthalate (SP value 9.73 (cal / cm 3) 1/2), di2-ethylhexyl phthalate (SP value 9. 73 (cal / cm 3) 1/2), dinonyl phthalate (SP value 9.30 (cal / cm 3) 1/2), diisononyl phthalate (DINP, SP value 9.64 (cal / cm 3) 1) / 2), diisodecyl phthalate (SP value 9.57 (cal / cm 3) 1/2), ditridecyl phthalate (SP value 9.48 (cal / cm 3) 1/2), dibutylpentyl phthalate (SP) A value of 9.64 (cal / cm 3) 1/2) and the like can be mentioned. These can be used alone or in combination of two or more.
[0116]
Examples of the adipate ester include diisononyl adipate (DINA, SP value 9.13 (cal / cm 3) 1/2), dioctyl adipate (SP value 9.18 (cal / cm 3) 1/2), and the like. Examples thereof include diisodecyl adipate (SP value 9.09 (cal / cm 3) 1/2). These can be used alone or in combination of two or more.
[0117]
Examples of the benzoic acid ester include benzoic acid glycol ester (trade name: Benzoflex (registered trademark) grade No. 9-88SG, manufactured by Eastman Chemical Co., Ltd., SP value 10.86 (cal / cm 3) 1/2). Diethylene glycol dibenzoate (SP value 11.30 (cal / cm 3) 1/2), cyclohexane-1,4-diyldimethylene = dibenzoate (SP value 10.99 (cal / cm 3) 1/2), etc. Can be mentioned. These can be used alone or in combination of two or more.
[0118]
Examples of the hydrogenated phthalate ester include hydrogenated diisononyl phthalate (DINCH, SP value 9.22 (cal / cm 3) 1/2). These can be used alone or in combination of two or more.
[0119]
These plasticizers can be used alone or in combination of two or more.
[0120]
Further, the compatibilizer is not limited to the plasticizer, and examples thereof include an organic solvent having an SP value in the above range.
[0121]
Examples of the organic solvent include aromatic hydrocarbons such as toluene (SP value 9.14 (cal / cm 3) 1/2) and o-xylene (SP value 9.10 (cal / cm 3) 1/2). , For example, acetone (SP value 9.07 (cal / cm 3) 1/2), methyl ethyl ketone (SP value 8.98 (cal / cm 3) 1/2), cyclohexanone (SP value 9.80 (cal / cm) 1/2). 3) Ketones such as 1/2), for example, ethyl acetate (SP value 8.74 (cal / cm 3) 1/2), butyl acetate (SP value 8.70 (cal / cm 3) 1/2), etc. Estes such as tetrahydrofuran (THF, SP value 8.28 (cal / cm 3) 1/2) and other ethers such as N, N-dimethylformamide (DMF, SP value 10.2 (cal / cm 3)). Examples thereof include polar aprotons such as 1/2).
[0122]
These organic solvents can be used alone or in combination of two or more.
[0123]
As the compatibilizer, a plasticizer is preferably used from the viewpoint of adhesive strength, and a carboxylic acid ester-based plasticizer is more preferable, and a phthalate ester, an adipic acid ester, and a benzoic acid ester are more preferable. Hydrogenated phthalates are mentioned, more preferably benzoic acid esters.
[0124]
From the viewpoint of adhesive strength, the SP value of the compatibilizer is 7.5 (cal / cm 3) 1/2 or more, preferably 8.0 (cal / cm 3) 1/2 or more, more preferably. , 8.5 (cal / cm 3) 1/2 or more, more preferably 9.0 (cal / cm 3) 1/2 or more, still more preferably 9.5 (cal / cm 3) 1/2 or more. Particularly preferably, it is 10.0 (cal / cm 3) 1/2 or more, 13.0 (cal / cm 3) 1/2 or less, preferably 12.5 (cal / cm 3) 1/2. Below, more preferably 12.0 (cal / cm 3) 1/2 or less, still more preferably 11.5 (cal / cm 3) 1/2 or less, and particularly preferably 11.0 (cal / cm 3). ) It is 1/2 or less.
[0125]
In the polyisocyanate component, the content of the compatibilizer is appropriately set according to the content of the isocyanate group-terminated urethane prepolymer and the derivative of xylylene diisocyanate, their isocyanate group equivalents, the isocyanate group content, and the like.
[0126]
For example, from the viewpoint of adhesive strength, the content of the compatibilizer is, for example, 10 parts by mass or more, preferably 30 parts by mass or more, more preferably 30 parts by mass or more, based on 100 parts by mass of the derivative of xylylene diisocyanate. 50 parts by mass or more, more preferably 70 parts by mass or more, particularly preferably 90 parts by mass or more, for example, 500 parts by mass or less, preferably 400 parts by mass or less, more preferably 300 parts by mass or less, further It is preferably 200 parts by mass or less, and particularly preferably 150 parts by mass or less.
[0127]
The polyol component contains macropolyol having a number average molecular weight of 500 or more and 10,000 or less and an average number of hydroxyl groups of 1.9 or more and 4.0 or less as essential components.
[0128]
Examples of macropolyols include polyether polyols, polyester polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, polymer polyols, and the like.
[0129]
Examples of the polyether polyol include polyoxy (C2 to 3) alkylene polyol and polytetramethylene ether polyol.
[0130]
The polyoxy (C2 to 3) alkylene polyol is an addition polymer of an alkylene oxide having 2 to 3 carbon atoms, for example, using the above-mentioned low molecular weight polyol or a known polyamine compound as an initiator.
[0131]
Examples of the alkylene oxide include propylene oxide and ethylene oxide. In addition, these alkylene oxides can be used alone or in combination of two or more. The polyoxyalkylene polyol includes, for example, a random and / or block copolymer of propylene oxide and ethylene oxide.
[0132]
More specific examples of the polyoxy (C2 to 3) alkylene polyol include polyoxyethylene polyol, polyoxypropylene polyol, and polyoxyethylene / polyoxypropylene (random and / or block) copolymer.
[0133]
Examples of the polytetramethylene ether polyol include a ring-opened polymer obtained by cationic polymerization of tetrahydrofuran, and amorphous (non-crystalline) obtained by copolymerizing an alkyl-substituted tetrahydrofuran or the above-mentioned divalent alcohol with a polymerization unit such as tetrahydrofuran. Sex) Polytetrahydrofuran ether glycol and the like can be mentioned.
[0134]
Amorphous (amorphous) means that it is liquid at room temperature (25 ° C).
[0135]
The amorphous polytetramethylene ether glycol is, for example, a copolymer of tetrahydrofuran and alkyl-substituted tetrahydrofuran (for example, 3-methyltetrahydrofuran) (tetrahydrofuran / alkyl-substituted tetrahydrofuran (molar ratio) = 15/85 to 85 /. 15, number average molecular weight 500 to 4000, preferably 800 to 2500), or a copolymer of, for example, tetrahydrofuran and branched glycol (eg, neopentyl glycol) (tetrahydrofuran / branched glycol (molar ratio) = It can be obtained as 15/85 to 85/15, a number average molecular weight of 500 to 4000, preferably 800 to 2500) and the like.
[0136]
Examples of the polyester polyol include a polycondensate obtained by reacting the above-mentioned low molecular weight polyol with a polybasic acid under known conditions.
[0137]
Examples of the polybasic acid include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid. , Adipic acid, sebacic acid,Other saturated aliphatic dicarboxylic acids (C11-13), such as maleic acid, fumaric acid, itaconic acid, and other unsaturated aliphatic dicarboxylic acids, such as orthophthalic acid, isophthalic acid, terephthalic acid, toluenedicarboxylic acid, naphthalene. From dicarboxylic acids, other aromatic dicarboxylic acids such as hexahydrophthalic acid, other alicyclic dicarboxylic acids such as dimer acid, hydrogenated dimer acid, hetic acid and other carboxylic acids, and their carboxylic acids. Derived acid anhydrides such as oxalic acid anhydride, succinic acid anhydride, maleic anhydride, phthalic acid anhydride, 2-alkyl anhydride (C12-C18) succinic acid, tetrahydrophthalic acid anhydride, trimellitic acid anhydride, and further. Acid halides derived from these carboxylic acids and the like, for example, oxalic acid dichloride, adipic acid dichloride, sebacic acid dichloride and the like can be mentioned.
[0138]
Further, as the polyester polyol, for example, a plant-derived polyester polyol, specifically, the above-mentioned low molecular weight polyol as an initiator, a hydroxyl group-containing vegetable oil fatty acid (for example, castor oil fatty acid containing ricinoleic acid, 12-hydroxystearic acid). Examples thereof include vegetable oil-based polyester polyols obtained by subjecting a hydroxycarboxylic acid such as (hydrogenated castor oil fatty acid, etc.) containing the above to a condensation reaction under known conditions.
[0139]
Further, as the polyester polyol, for example, using the above-mentioned low molecular weight polyol (preferably dihydric alcohol) as an initiator, for example, lactones such as ε-caprolactone and γ-valerolactone, and for example, L-lactide, D- Examples thereof include polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactides such as lactide, and lactone-based polyester polyols obtained by copolymerizing them with the above-mentioned divalent alcohol.
[0140]
Examples of the polycarbonate polyol include a ring-opening polymer of ethylene carbonate using the above-mentioned low molecular weight polyol (preferably a dihydric alcohol) as an initiator, and for example, 1,4-butanediol and 1,5-pentanediol. Examples thereof include an amorphous polycarbonate polyol obtained by copolymerizing a dihydric alcohol such as 3-methyl-1,5-pentanediol or 1,6-hexanediol with a ring-opening polymer.
[0141]
Further, the polyurethane polyol is a polyester polyol, a polyether polyol and / or a polycarbonate polyol obtained as described above, at a ratio in which the equivalent ratio (OH / NCO) of the hydroxyl group (OH) to the isocyanate group (NCO) exceeds 1. By reacting with polyisocyanate, it can be obtained as a polyester polyurethane polyol, a polyether polyurethane polyol, a polycarbonate polyurethane polyol, a polyester polyether polyurethane polyol, or the like.
[0142]
Examples of the epoxy polyol include an epoxy polyol obtained by reacting the above-mentioned low molecular weight polyol with a polyfunctional halohydrin such as epichlorohydrin and β-methylepichlorohydrin.
[0143]
Examples of the vegetable oil polyol include hydroxyl group-containing vegetable oils such as castor oil and coconut oil. For example, castor oil polyol or ester-modified castor oil polyol obtained by reacting castor oil fatty acid with polypropylene polyol may be mentioned.
[0144]
Examples of the polyolefin polyol include polybutadiene polyol and a partially Ken-valent ethylene-vinyl acetate copolymer.
[0145]
Examples of the acrylic polyol include a copolymer obtained by copolymerizing a hydroxyl group-containing acrylate and a copolymerizable vinyl monomer copolymerizable with the hydroxyl group-containing acrylate.
[0146]
Examples of the hydroxyl group-containing acrylate include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2-dihydroxymethylbutyl (meth) acrylate, and polyhydroxyalkylmalate. Examples thereof include polyhydroxyalkyl fumarate. Preferably, 2-hydroxyethyl (meth) acrylate and the like can be mentioned.
[0147]
Examples of the copolymerizable vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and s-butyl ( Alkyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, isononyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl acrylate, etc. Meta) acrylates (1-12 carbon atoms), eg aromatic vinyls such as styrene, vinyl toluene, α-methylstyrene, eg vinyl cyanide such as (meth) acrylonitrile, eg (meth) acrylic acid, fumaric acid , Maleic acid, vinyl monomer containing a carboxyl group such as itaconic acid, or an alkyl ester thereof, for example, ethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexanediol di (meth) acrylate, oligoethylene glycol. Alcan polyol poly (meth) acrylates such as di (meth) acrylates, trimethylolpropane di (meth) acrylates, trimethylolpropane tri (meth) acrylates, for example 3- (2-isocyanate-2-propyl) -α-methyl Examples thereof include vinyl monomers containing an isocyanate group such as styrene.
[0148]
Then, the acrylic polyol can be obtained by copolymerizing these hydroxyl group-containing acrylates and copolymerizable vinyl monomers in the presence of a suitable solvent and polymerization initiator.
[0149]
Further, the acrylic polyol includes, for example, a silicone polyol and a fluorine polyol.
[0150]
Examples of the silicone polyol include a modified polysiloxane polyol in which a hydroxyl group is introduced into a dialkylpolysiloxane, and for example, in the above-mentioned copolymerization of the acrylic polyol, the copolymerizable vinyl monomer includes, for example, γ-methacryloxypropyltrimethoxysilane. Examples thereof include an acrylic polyol containing a silicone compound containing a vinyl group of.
[0151]
Examples of the fluorine polyol include, in the above-mentioned copolymerization of the acrylic polyol, an acrylic polyol in which a fluorine compound containing a vinyl group such as tetrafluoroethylene and chlorotrifluoroethylene is blended as the copolymerizable vinyl monomer. ..
[0152]
The polymer polyol can be obtained by dispersing and polymerizing a vinyl monomer in the above-mentioned macropolypoly (for example, polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, epoxy polyol, vegetable oil polyol, polyolefin polyol, acrylic polyol, etc.). Can be done.
[0153]
As the macropolyol in the polymer polyol, preferably, a polyether polyol is mentioned, and more preferably, a polyoxy (C2 to 3) alkylene polyol is mentioned.
[0154]
More specifically, in the polymer polyol, the vinyl monomer is polymerized in the macropolypoly by a radical initiator (for example, persulfate, organic peroxide, azo compound (azobisisobutyronitrile, etc.)). It is prepared by dispersing the obtained polymer fine particles in a macropolypoly.
[0155]
Examples of the vinyl monomer include styrene, acrylamide, alkyl (meth) acrylate, vinyl cyanide (acrylonitrile), vinylidene cyanide, and the like. These vinyl monomers can be used alone or in combination of two or more. Of these, styrene, vinyl cyanide (acrylonitrile), styrene and vinyl cyanide are preferably used in combination.
[0156]
The content of the polymer of the vinyl monomer with respect to the polymer polyol is, for example, 2% by mass or more, preferably 5% by mass or more, and for example, 50% by mass or less, preferably 45% by mass or less.
[0157]
In the polyol component, the number average molecular weight of the macropolyol (polystyrene-equivalent molecular weight measured by the gel permeation chromatogram method) is 500 or more, preferably 1000 or more, more preferably 1500 or more from the viewpoint of adhesive strength. It is 10,000 or less, more preferably 7500 or less, and more preferably 5000 or less.
[0158]
Further, in the polyol component, the hydroxyl group equivalent of the macropolyol is, for example, 150 or more, preferably 200 or more, and for example, 10,000 or less, preferably 8000 or less.
[0159]
In the polyol component, the average number of hydroxyl groups of the macropolyol is 1.9 or more, preferably 2.0 or more, more preferably 2.3 or more, and 4.0 or less, preferably 4.0 or less, from the viewpoint of adhesive strength. Is 3.5 or less, more preferably 3.0 or less.
[0160]
Examples of the macropolyol in the polyol component (preferably a curing agent) include a polyether polyol and a vinyl monomer-modified polyol (also known as a polymer polyol).
[0161]
From the viewpoint of adhesive strength, the polyol component particularly preferably contains a polyether polyol.
[0162]
In such a case, the content ratio of the polyether polyol is, for example, 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and usually, with respect to the total amount of the polyol components. It is 100% by mass or less.
[0163]
Further, the polyol component can include the above-mentioned low molecular weight polyol, if necessary. The low molecular weight polyols can be used alone or in combination of two or more.
[0164]
The content ratio of the low molecular weight polyol to the polyol component is appropriately selected as long as the excellent effect of the present invention is not impaired.
[0165]
More specifically, the content ratio of the low molecular weight polyol is, for example, 30 parts by mass or less, preferably 20 parts by mass or less, and more preferably 10 parts by mass or less with respect to 100 parts by mass of the total amount of the polyol components. , Particularly preferably 0 parts by mass.
[0166]
That is, from the viewpoint of adhesive strength, the polyol component preferably does not contain a low molecular weight polyol and is composed of a macropolyol.
[0167]
Further, the structural polyurethane adhesive may be an additive other than a compatibilizer, for example, a urethanization catalyst, an antioxidant, an antioxidant, an ultraviolet absorber, a heat-resistant stabilizer, a polymer light stabilizer, etc., if necessary. Stabilizers, organic solvents, pigments, dyes, defoaming agents, dispersants, leveling materials, thixo-imparting agents, anti-blocking agents, mold release agents, lubricants, interlayer adjusters (glass beads, etc.), fillers, viscosity adjusters It can contain known additives such as.
[0168]
The content ratio of the additive is not particularly limited and is appropriately set according to the purpose and application.
[0169]
The additive may be contained in, for example, a polyisocyanate component (for example, the main ingredient of a two-component curable adhesive) or a polyol component (for example, a curing agent for a two-component curable adhesive). It may be contained in both of them, and in addition, it may be contained in a mixture of a polyisocyanate component and a polyol component (for example, a one-component curable adhesive).) May be contained.
[0170]
On the other hand, the structural polyurethane adhesive preferably does not contain an organic solvent from the viewpoint of workability. That is, the structural polyurethane adhesive is preferably a solvent-free adhesive.
[0171]
In the solvent-free adhesive, the polyisocyanate component is prepared, for example, without using an organic solvent, or is prepared using an organic solvent, and then desolvated by a known method.
[0172]
Further, in the solvent-free adhesive, the polyol component is prepared, for example, without using an organic solvent, or is prepared using an organic solvent, and then desolvated by a known method.
[0173]
Further, as described above, the structural polyurethane adhesive is preferably a two-component curable adhesive comprising a main agent composed of a polyisocyanate component and a curing agent composed of a polyol component. The two-component curable adhesive is a resin composition kit (two-component kit) for forming a cured product by blending (mixing) a separately prepared main agent and a curing agent at the time of use. That is, a resin mixture (polyurethane mixture) is obtained by mixing the main agent and the curing agent, and a cured product (polyurethane cured product) is obtained by the curing reaction of the resin mixture.
[0174]
In such a structural polyurethane adhesive, the polyisocyanate component contains a urethane prepolymer having an isocyanate group at the molecular terminal and a derivative of xylylene diisocyanate, and the polyol component has a number average molecular weight and an average hydroxyl group. Since it contains macropolyurethane in a predetermined range, excellent adhesive strength can be obtained.
[0175]
Therefore, the above-mentioned structural polyurethane adhesive is suitably used for adhering each member in a structure composed of a plurality of members and the like. Examples of the members of the structure include members of buildings, automobiles, transportation equipment, ships, and the like.
[0176]
In the use of structural polyurethane adhesives, for example, a mixture containing a polyisocyanate component and a polyol component is applied to a member by a known method, cured, and cured if necessary.
[0177]
From the viewpoint of workability, the viscosity of the mixture containing the polyisocyanate component and the polyol component at 25 ° C. is, for example, 100 mPa · s or more, preferably 300 mPa · s or more, for example, 20000 mPa · s or less, preferably 10000 mPa.・ It is less than or equal to s.
[0178]
As the curing conditions, the curing temperature is, for example, 10 ° C. or higher, preferably 20 ° C. or higher, for example, 80 ° C. or lower, preferably 60 ° C. or lower. The curing time is, for example, 0.5 hours or more, preferably 1 hour or more, for example, 10 hours or less, preferably 5 hours or less.
[0179]
As the curing conditions, the curing temperature is, for example, 20 ° C. or higher, preferably 25 ° C. or higher, for example, 80 ° C. or lower, preferably 70 ° C. or lower. The curing time is, for example, 1 hour or more, preferably 2 hours or more, for example, 72 hours or less, preferably 24 hours or less.
[0180]
As a result, the structural polyurethane adhesive can be cured and each member can be adhered well.
Example
[0181]
Next, the present invention will be described based on Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, "part" and "%" are based on mass unless otherwise specified. In addition, specific numerical values ​​such as the compounding ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned "Mode for carrying out the invention", and the compounding ratios corresponding to them ( Substitute the upper limit value (value defined as "less than or equal to" or "less than") or the lower limit value (value defined as "greater than or equal to" or "excess") such as content ratio), physical property value, parameter, etc. be able to.
[0182]
(Preparation example 1) Isocyanate group-terminated urethane prepolymer
700 g of a polyether polyol having an average number of hydroxyl groups of 2 (trade name: Actol D-2000, number average molecular weight of 2000, manufactured by Mitsui Kagaku SKC polyurethane), and a polyether polyol having an average number of hydroxyl groups of 3 (trade name: Actol T-3000, number). 300 g of Mitsui Kagaku SKC polyurethane with an average molecular weight of 3000 and 249 g of 4,4′-diphenylmethane diisocyanate (MDI) were mixed. The equivalent ratio (NCO / OH) at this time was 2.0.
[0183]
Next, the obtained mixture was stirred at 80 ° C. for 12 hours in a nitrogen stream to cause a urethanization reaction. As a result, an isocyanate group-terminated urethane prepolymer (MDI-based prepolymer) having an isocyanate group content of 3.36% by mass was obtained.
[0184]
The isocyanate group equivalent of the obtained MDI-based prepolymer (measured according to the method A of JIS K 1603-1 (2007) (the same applies hereinafter)) was 1250.
[0185]
(Preparation example 2) Isocyanurate derivative of xylylene diisocyanate
A composition containing an isocyanurate derivative of alcohol-modified xylylene diisocyanate (hereinafter referred to as XDI derivative 1) was obtained by the method described in Example 1 of JP-A-2019-59821.
[0186]
That is, under a nitrogen atmosphere, 1,3-xylylene diisocyanate (m-XDI (hereinafter, XDI), acidity 50 ppm) 787.470 parts by mass and octadecyl 3- (3,5-di-tert-butyl-4-hydroxy). Phenyl) propionate (hindered phenolic antioxidant, trade name: Irganox 1076, manufactured by Ciba Japan) 0.161 parts by mass is mixed at 60 ° C to 65 ° C, and dodecylbenzenesulfonic acid (DDBSA, A propylene glycol methyl ether acetate solution (active ingredient concentration: 50% by mass) of (catalyst deactivator) was added at a ratio of DDBSA to 0.064 parts by mass.
[0187]
Next, 15.726 parts by mass of 1,3-butanediol was added to the mixture, and the urethanization reaction was carried out at 70 ° C. to 75 ° C.
[0188]
Next, a propylene glycol methyl ether acetate solution (solid content concentration 3.7% by mass) of tetrabutylammonium hydroxide (isocyanurate catalyst, TBAOH (37% methanol solution)) was added to the obtained urethane reaction solution. .. The amount added was adjusted so that TBAOH (37% methanol solution) was 0.803 parts by mass.
[0189]
Next, while mixing the urethane reaction solution, XDI was subjected to an isocyanurate-forming reaction at 70 ° C. to 75 ° C. until the conversion rate reached 30%.
[0190]
Next, a propylene glycol methyl ether acetate solution (active ingredient concentration 50% by mass) of dodecylbenzenesulfonic acid (DDBSA, catalytic deactivator) was added to the obtained isocyanurate reaction solution to stop the isocyanurate-forming reaction. .. The addition amount was adjusted so that DDBSA was 0.415 parts by mass (the addition ratio of DDBSA was 500 ppm with respect to the isocyanate reaction solution).
[0191]
Next, the obtained isocyanate reaction solution was further stirred at 70 to 75 ° C. for 30 minutes. Next, in order to adjust the acidity, 20.562 parts by mass of XDI having a high acidity (acidity 2400 ppm) prepared in advance was added to the isocyanate reaction solution, and the mixture was stirred for 30 minutes and then cooled to 50 ° C. or lower. Next, the obtained isocyanurate reaction solution was subjected to thin film distillation (pressure: ~ 60 PaA, water vapor pressure: 0.7 MPaG, temperature: 170 ° C., feed amount: 200 kg / hr) to carry out isocyanurate of alcohol-modified xylylene diisocyanate. A composition containing a derivative (XDI derivative 1) was obtained. The isocyanate group equivalent of the XDI derivative 1 was 239.4.
[0192]
(Preparation example 3) Alofanate derivative of xylylene diisocyanate
In a 1-liter capacity four-necked flask equipped with a stirrer, thermometer, cooler and nitrogen gas introduction tube, under a nitrogen atmosphere, 100 parts by mass of 1,3-xylylene diisocyanate (m-XDI) and isobutanol ( IBA) 15.8 parts by mass (equivalent ratio NCO / OH = 5), tris (2-ethylhexyl) phosphite (antioxidant) 0.06 parts by mass, and pentaerythritol tetrakis [3- (3,5-di-) t-Butyl-4-hydroxyphenyl) propionate] (antioxidant) 0.06 part by mass was charged and subjected to a urethanization reaction at 75 ° C. for 3.5 hours. As a result, a urethane product was obtained.
[0193]
Next, 0.06 parts by mass of XK-628 (trade name, manufactured by Kusumoto Kasei Co., Ltd., bismuth carboxylate, bismuth content ratio: 31% by mass) as an allophanation catalyst was added to the reaction solution containing the urethanized product at 90 ° C. The allophanate reaction was carried out for 11 hours, and it was confirmed that the conversion of the urethane bond to the allophanate bond was almost completed (the IR ratio of the urethane group / allophanate group was 0.1 or less), and the orthotoluenesulfonamide (reaction terminator) was 0. .10 parts by mass was added to terminate the allophanation reaction.
[0194]
Then, unreacted isobutanol and 1,3-xylylene diisocyanate were distilled off (removed) from the obtained reaction solution by a thin film distillation apparatus (vacuum degree: 0.05 kPa, temperature 150 ° C.), and the xylylene diisocyanate was distilled off. A composition containing the allophanate derivative of (hereinafter referred to as XDI derivative 2) was obtained. The isocyanate group equivalent of the XDI derivative 2 was 259.
[0195]
(Preparation example 4) Biuret derivative of xylylene diisocyanate
Takenate A-14 (trade name, manufactured by Mitsui Chemicals) was desolvated with an evaporator to obtain a composition containing a biuret derivative of xylylene diisocyanate (hereinafter referred to as XDI derivative 3). The isocyanate group equivalent of the XDI derivative 3 was 202.
[0196]
(Preparation example 5) Polyol derivative of xylylene diisocyanate (alcohol adduct)
A composition containing Takenate D-110N (trade name, manufactured by Mitsui Chemicals, trimethylolpropane adduct of xylylene diisocyanate) desolvated by an evaporator and containing a polyol derivative (alcohol adduct) of xylylene diisocyanate (hereinafter, XDI). It is referred to as derivative 4). The isocyanate group equivalent of the XDI derivative 4 was 243.
[0197]
(Preparation example 6) Isocyanurate derivative of pentamethylene diisocyanate
A composition containing an isocyanurate derivative of pentamethylene diisocyanate (hereinafter referred to as a PDI derivative) was obtained in accordance with the description of Example 1 of JP-A-2010-254764. The isocyanate group equivalent of the PDI derivative was 168.
[0198]
Examples 1 to 19 and Comparative Examples 1 to 2
The isocyanate group-terminated urethane prepolymer, the XDI derivative or the PDI derivative, and the compatibilizer were mixed according to the formulations shown in Tables 1 to 3. As a result, a polyisocyanate component (main agent) was obtained.
[0199]
Further, macropolyols were mixed according to the formulations shown in Tables 1 to 3 to obtain a polyol component (curing agent).
[0200]
As a result, a structural polyurethane adhesive containing a polyisocyanate component and a polyol component was obtained.
[0201]
(evaluation)
(1) Preparation of test board
A polypropylene plate (J707G, made of prime polymer) was corona-treated, the wettability (JIS K 6768 (1999)) was adjusted to 40 dyn / cm or more, and the material was cut to a width of 25 mm. This was designated as the adherend 1.
[0202]
On the other hand, the cold-rolled steel sheet (SPCC) was cut to a width of 25 mm. This was designated as the adherend 2.
[0203]
Then, the polyisocyanate component and the polyol component were mixed at a ratio of an equivalent ratio (NCO / OH) of 1.0. Then, glass beads (ASGB-60, manufactured by AS ONE, 0.250 to 0.355 mm) for adjusting the layer thickness were added to the obtained mixture. The amount of glass beads added is the polyisocyanate component., The total amount of the polyol component and the glass beads was adjusted to 1% by mass.
[0204]
Then, the obtained mixture is applied to the adherend 1, and the adherend 1 and the adherend 2 are brought into close contact with each other so that the adhesive area is 25 mm × 12.5 mm and the adhesive layer thickness is 0.3 mm. It was cured at 25 ° C. for 1 hour and cured at 60 ° C. for 24 hours. As a result, a test plate was obtained.
[0205]
Further, instead of the polypropylene plate, carbon fiber reinforced plastic (CFRP (matte), manufactured by Standard Testpiece Co., Ltd.) which has not been subjected to corona treatment is used as the adherend 1, and Examples 1 and 8 are also used. , Comparative Example 1 and Comparative Example 2 were used to obtain a test plate using the polyisocyanate component and the polyol component.
[0206]
(2) Measurement of adhesive strength
The shear peel strength between the adherend 1 and the adherend 2 was measured by a tensile tester (U-4410, manufactured by Orientec Co., Ltd.) at a tensile speed of 50 mm / min, and evaluated according to the following criteria.
◎; 340 N / cm 2 or more
◯; 300 N / cm 2 or more
Δ; 190 N / cm 2 or more
×; 190 N / cm less than 2
[0207]
[table 1]

[0208]
[Table 2]

[0209]
[Table 3]

[0210]
The details of the abbreviations in the table are shown below.
MDI prepolymer: MDI urethane prepolymer obtained in Preparation Example 1
XDI Derivative 1: A composition containing the isocyanurate derivative of xylylene diisocyanate obtained in Preparation Example 2.
XDI Derivative 2: A composition containing an allophanate derivative of xylylene diisocyanate obtained in Preparation Example 3.
XDI Derivative 3: A composition containing the biuret derivative of xylylene diisocyanate obtained in Preparation Example 4.
XDI Derivative 4: A composition containing a polyol derivative of xylylene diisocyanate obtained in Preparation Example 5.
PDI derivative: A composition containing the isocyanurate derivative of pentamethylene diisocyanate obtained in Preparation Example 6.
DMP: Dimethyl phthalate, SP value 11.54 (cal / cm 3) 1/2, compatibilizer (plasticizer)
DEP: Diethyl phthalate, SP value 11.07 (cal / cm 3) 1/2, compatibilizer (plasticizer)
Benzoflex: Brand name Benzoflex (registered trademark) Grade No. 9-88SG, manufactured by Eastman Chemical Company, benzoic acid glycol ester, SP value 10.86 (cal / cm 3) 1/2, compatibilizer (plasticizer)
DINP: Diisononyl phthalate, SP value 9.57 (cal / cm 3) 1/2, compatibilizer (plasticizer)
DINA: diisononyl adipate, SP value 9.13 (cal / cm 3) 1/2, compatibilizer (plasticizer)
DINCH: Hydrogenated diisononyl phthalate, SP value 9.22 (cal / cm 3) 1/2, compatibilizer (plasticizer)
THF: tetrahydrofuran, SP value 8.28 (cal / cm 3) 1/2, compatibilizer (organic solvent)
DMF: N, N-dimethylformamide, SP value 10.2 (cal / cm 3) 1/2, compatibilizer (organic solvent)
POP3128: Brand name Actol POP-3128, Mitsui Chemicals SKC polyurethane, vinyl monomer modified polyol (also known as polymer polyol), hydroxyl group equivalent 2003, average number of hydroxyl groups 3, number average molecular weight about 6000
DL-10000: Brand name Actcol DL-10000, Mitsui Chemicals SKC polyurethane, polyether polyol, hydroxyl group equivalent 5000, average number of hydroxyl groups 2, number average molecular weight 2000
DL-4000: Brand name Actcol DL-4000, made by Mitsui Chemicals SKC polyurethane, polyether polyol, hydroxyl group equivalent 2000, average number of hydroxyl groups 2, number average molecular weight 4000
T-1000: Brand name Actol T-1000, made by Mitsui Chemicals SKC polyurethane, polyether polyol, hydroxyl group equivalent 333, average number of hydroxyl groups 3, number average molecular weight 1000
T-700: Brand name Actol T-700, made by Mitsui Chemicals SKC polyurethane, polyether polyol, hydroxyl group equivalent 233, average number of hydroxyl groups 3, number average molecular weight 700
T-300: Brand name Actol T-300, made by Mitsui Chemicals SKC polyurethane, polyether polyol, hydroxyl group equivalent 100, average number of hydroxyl groups 3, number average molecular weight 300
PP: Polypropylene plate, J707G, made of prime polymer
CFRP: Carbon fiber reinforced plastic, CFRP (matte), made by Standard Test Piece
Although the above invention has been provided as an exemplary embodiment of the present invention, this is merely an example and should not be construed in a limited manner. Modifications of the present invention that will be apparent to those skilled in the art are included in the claims described below.
Industrial applicability
[0211]
The structural polyurethane adhesive of the present invention is suitably used for adhering each member in, for example, buildings, automobiles, transportation equipment and ships.
The scope of the claims
[Claim 1]
A urethane prepolymer having an isocyanate group at the molecular end, a polyisocyanate component containing a derivative of xylylene diisocyanate, and
With a polyol component containing a macropolyol having a number average molecular weight of 500 or more and 10000 or less and an average number of hydroxyl groups of 1.9 or more and 4.0 or less.
A structural polyurethane adhesive characterized by containing.
[Claim 2]
The polyisocyanate component contains a compatibilizer for compatibilizing the urethane prepolymer and the derivative of xylylene diisocyanate.
The solubility parameter of the compatibilizer determined by the Fedors formula is 7.5 (cal / cm 3) 1/2 or more and 13.0 (cal / cm 3) 1/2 or less.
The structural polyurethane adhesive according to claim 1.
[Claim 3]
The compatibilizer is at least one plasticizer selected from the group consisting of phthalates, adipates, benzoic acids and hydrogenated phthalates.
The structural polyurethane adhesive according to claim 2.
[Claim 4]
The derivative of xylylene diisocyanate contains an isocyanurate derivative of xylylene diisocyanate.
The structural polyurethane adhesive according to claim 1.
[Claim 5]
The content of the derivative of xylylene diisocyanate is 1.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the total amount of the urethane prepolymer.
The structural polyurethane adhesive according to claim 1.
[Claim 6]
In the above-mentioned polyol component, the macropolyol contains a polyether polyol.
The structural polyurethane adhesive according to claim 1.
[Claim 7]
The urethane prepolymer is a reaction product of a raw material polyisocyanate containing diphenylmethane diisocyanate and a raw material polyol containing a macropolyol.
The structural polyurethane adhesive according to claim 1.
[Claim 8]
A two-component curable adhesive comprising a main agent composed of the polyisocyanate component and a curing agent composed of the polyol component.
The structural polyurethane adhesive according to claim 1.
[Claim 9]
The structural polyurethane adhesive according to claim 1, which is a solvent-free adhesive.