Title of Invention: Water Dispersion and Laminate
Technical field
[0001]
The present invention relates to aqueous dispersions and laminates, and more particularly to aqueous dispersions and laminates obtained using the aqueous dispersions.
Background technology
[0002]
Conventionally, in various industrial fields, substrates such as plastic films, vapor-deposited films, metal foils, paper, nonwoven fabrics, etc., or substrates and other adherends are laminated by heat and pressure (that is, heat-sealed). It has been known. When heat-sealing, a method of directly bonding substrates to each other or a substrate and an adherend is usually used. A method is also used in which a heat-sealing agent (adhesive) layer is formed on a substrate in advance, and the substrates are bonded to each other or to another adherend via the adhesive layer.
[0003]
As an adhesive used for such heat sealing, for example, a polymer containing a resin component and water, and having an ethylene/unsaturated carboxylic acid copolymer and an acrylic acid ester unit as polymerized units as the resin component. An aqueous dispersion containing coalescence and an ethylene/vinyl acetate copolymer has been proposed, and a laminate is also proposed in which the aqueous dispersion is applied to a substrate and dried to form a coating film on the surface of the substrate. It is (See Patent Document 1, for example).
prior art documents
patent literature
[0004]
Patent Document 1: International Publication No. 2018/142997
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0005]
The coating film (heat sealant) formed on the surface of the base material should have a low coefficient of dynamic friction on the surface from the viewpoint of facilitating transportation of the laminate in the work place or improving the filling efficiency of the contents. requested. It is also desired that the coating film has a small coefficient of dynamic friction immediately after the coating film is formed.
[0006]
That is, the object of the present invention is to provide an aqueous dispersion capable of forming a coating film with low dynamic friction resistance immediately after coating, and to provide a laminate of a substrate and a coating film with low dynamic friction resistance. and
Means to solve problems
[0007]
The present invention relates to the following [1] to [7].
[1] Aqueous dispersion containing polyolefin (A), unsaturated carboxylic acid polymer (B), amide wax (C) and water.
[0008]
[2] The aqueous dispersion according to [1] above, wherein the concentration of the amide wax (C) is 0 with respect to component (A) + component (B) = 100 parts by mass of the aqueous dispersion. .15 to 3.0 parts by mass of an aqueous dispersion.
[0009]
[3] The unsaturated carboxylic acid polymer (B) comprises an ethylene/unsaturated carboxylic acid copolymer (b1) and/or a salt thereof (B1), and a (meth)acrylic acid ester polymer (B2). The aqueous dispersion of [1] or [2], which is at least one selected from the group.
[0010]
[4] Composite particles in which the unsaturated carboxylic acid polymer (B) comprises the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) and the acrylic acid ester polymer (B2) The aqueous dispersion according to any one of [1] to [3] above.
[5] A base material and an adhesive layer laminated on at least a part of at least one surface of the base material, wherein the adhesive layer is the water dispersion according to any one of [1] to [4]. Laminate consisting of dried body.
[0011]
[6] The laminate according to [5], further comprising an adherend layer laminated on the surface of the adhesive layer opposite to the substrate side.
[7] The laminate according to [5] or [6], wherein the substrate is made of aluminum.
Effect of the invention
[0012]
According to the aqueous dispersion of the present invention, a coating film with low dynamic friction resistance can be formed immediately after coating on the substrate. In addition, the dynamic friction resistance of the coating film of the laminate of the present invention is small.
Brief description of the drawing
[0013]
1 shows the relationship between the amount of wax added to a water dispersion and the dynamic friction coefficient of a coating film formed from the water dispersion in Example 1 and Comparative Example 1. FIG.
2] FIG. 2 shows the relationship between the standing time after coating of the aqueous dispersion and the dynamic friction coefficient of the coating film formed from the aqueous dispersion in Examples 1 and 2 and Comparative Example 2. [FIG.
3] Fig. 3 shows the relationship between the standing time after coating of the aqueous dispersion and the retention rate of the dynamic friction coefficient of the coating film formed from the aqueous dispersion in Examples 1 and 2 and Comparative Example 2. [Fig. .
MODE FOR CARRYING OUT THE INVENTION
[0014]
The present invention will be described in further detail below.
[Water dispersion]
The aqueous dispersion according to the present invention is characterized by containing polyolefin (A), unsaturated carboxylic acid polymer (B), amide wax (C) and water.
[0015]

The polyolefin (A) is an olefin homopolymer, a copolymer of two or more olefins, or a copolymer of an olefin and a diene.
[0016]
As the polyolefin (A), for example,
Low-density polyethylene, polyethylene such as high-density polyethylene, polypropylene, poly-1-butene, poly-3-methyl-1-butene, poly-4-methyl-1-pentene, poly-3-methyl-1-pentene, ethylene-propylene copolymer ethylene, propylene, propylene, propylene, ethylene, propylene, 2 to 12 carbon atoms such as 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-decene, and 1-dodecene such as an α-olefin homopolymer or copolymer of
Ethylene/butadiene copolymer, ethylene/ethylidenenorbornene copolymer, ethylene/propylene/butadiene terpolymer, ethylene/propylene/dicyclopentadiene terpolymer, ethylene/propylene/1,5-hexadiene ternary Copolymers of α-olefins and conjugated or non-conjugated dienes, typified by copolymers, may be mentioned.
[0017]
From the viewpoint of increasing the retention rate of the coefficient of dynamic friction, the polyolefin polymer (A) may be an ethylene homopolymer having a density of 900 kg/m 3 or more and 940 kg/m 3 or less, or ethylene mainly composed of ethylene. It is a preferred embodiment that the ethylene-based polymer (A1), which is a copolymer with an α-olefin, is included.
[0018]
The density of the ethylene polymer (A1) is preferably 900 kg/m 3 or more and 935 kg/m 3 or less.
The melting point of the ethylene polymer (A1) measured by differential scanning calorimetry (DSC) under the following conditions is preferably 95° C. or higher and 140° C. or lower, more preferably 95° C. or higher and 130° C. or lower. be.
[0019]
[DSC measurement conditions] Using a differential scanning calorimeter, a sample of about 5.0 mg is heated from 30°C to 200°C at a heating rate of 10°C/min in a nitrogen atmosphere, and held at that temperature for 10 minutes. Further, it is cooled to 30°C at a temperature decrease rate of 10°C/min, held at that temperature for 5 minutes, and then heated to 200°C at a temperature increase rate of 10°C/min. The endothermic peak observed during this second temperature rise is defined as the melting peak, and the temperature at which the melting peak appears is defined as the melting point. When the melting peaks are multimodal, the temperature at which the highest melting peak appears is taken as the melting point.
[0020]
Examples of the α-olefin in the ethylene/α-olefin copolymer that can be the ethylene polymer (A1) include propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl- Examples include α-olefins having 3 to 12 carbon atoms such as 1-pentene, 1-heptene, 1-hexene, 1-decene and 1-dodecene. Among these α-olefins, 1-hexene is preferred. The content (mol %) of structural units derived from α-olefin in the ethylene/α-olefin copolymer is preferably 0.01 to 10 mol %.
[0021]
The method for producing the ethylene-based polymer (A1) is not particularly limited as long as the polymer satisfies the desired physical properties.
Specific examples of the ethylene-based polymer (A1) include low-density polyethylene and linear low-density polyethylene.
[0022]
From the viewpoint of improving the low-temperature heat sealability of the laminate of the present invention, the polyolefin polymer (A) is an ethylene/α-olefin copolymer having a density of 860 kg/m 3 or more and 895 kg/m 3 or less. In one preferred embodiment, (A2) is included.
[0023]
The density of the ethylene/α-olefin copolymer (A2) is preferably 890 kg/m 3 or less, more preferably 880 kg/m 3 or less. The density of the ethylene/α-olefin copolymer (A2) is preferably 865 kg/m 3 or more.
[0024]
The melting point of the ethylene/α-olefin copolymer (A2) measured by DSC is usually 80°C or lower, preferably 70°C or lower. In the present invention, "° C. or less" means that polymers having no melting point are also included, as shown below. The above DSC means the melting point measured by DSC under the conditions described in the section of the ethylene polymer (A1).
[0025]
The ethylene/α-olefin copolymer (A2) may be amorphous, that is, may have no melting point, or may have a melting point of 40° C. or higher, or 50° C. or higher. good.
Examples of α-olefins constituting the ethylene/α-olefin copolymer (A2) include propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, and 3-methyl-1-pentene. , 1-heptene, 1-hexene, 1-decene, 1-dodecene, and other α-olefins having 3 to 12 carbon atoms. Among these α-olefins, 1-butene is preferred.
[0026]
The content (mol%) of structural units derived from α-olefins in the ethylene/α-olefin copolymer (A2) is preferably in the range of 5 to 50 mol%.
From the viewpoint of enhancing the heat-sealing property while increasing the retention rate of the coefficient of dynamic friction, it is preferable that the polyolefin (A) contains an ethylene-based polymer (A1) and an ethylene/α-olefin copolymer (A2). It is one form. Combinations of the ethylene polymer (A1) and the ethylene/α-olefin copolymer (A2) include, for example, low density polyethylene and ethylene/butene copolymer, linear low density polyethylene and ethylene/butene copolymer, include coalescence
From the viewpoint of improving both the retention rate of the coefficient of dynamic friction and the improvement of heat sealability, the mass ratio [(A1)/(A2 )] is preferably 90/10 to 10/90, more preferably 80/20 to 20/80.
[0027]
These polyolefins may be used singly or in combination of two or more.
[0028]

The unsaturated carboxylic acid polymer (B) is a polymer and/or a salt thereof containing an unsaturated carboxylic acid or an unsaturated carboxylic acid derivative such as an ester or an acid anhydride as a structural unit.
[0029]
Examples of the unsaturated carboxylic acid polymer (B) include an ethylene/unsaturated carboxylic acid copolymer (b1) which is a copolymer of ethylene and an unsaturated carboxylic acid and/or a salt thereof (B1), and Polymers (B2) of (meth)acrylic acid esters, which are derivatives of unsaturated carboxylic acids, can be mentioned.
[0030]

The ethylene/unsaturated carboxylic acid copolymer (b1) is a copolymer of ethylene and unsaturated carboxylic acid.
[0031]
The unsaturated carboxylic acid is a monomer having at least one ethylenically unsaturated bond and a carboxy group in one molecule, examples of which include monobasic acids such as acrylic acid, methacrylic acid, and crotonic acid, Examples thereof include dibasic acids such as maleic acid, fumaric acid and itaconic acid.
[0032]
　These unsaturated carboxylic acids may be used singly or in combination of two or more.
From the viewpoint of water resistance, the unsaturated carboxylic acid preferably includes a monobasic acid, and more preferably includes acrylic acid and methacrylic acid.
[0033]
Structural units derived from ethylene in the ethylene/unsaturated carboxylic acid copolymer (b1) (hereinafter also referred to as "ethylene units") and structural units derived from unsaturated carboxylic acids (hereinafter "unsaturated carboxylic acid units") The content of ethylene units is, for example, 75% by mass or more, preferably 78% by mass or more, for example 90% by mass or less, preferably 88% by mass or less, relative to the total amount of them. . Also, the unsaturated carboxylic acid unit is, for example, 10% by mass or more, preferably 12% by mass or more, and is, for example, 25% by mass or less, preferably 22% by mass or less.
[0034]
When the content of ethylene units and unsaturated carboxylic acid units in the ethylene/unsaturated carboxylic acid copolymer (b1) is within the above range, the coating film formed from the aqueous dispersion has excellent adhesive strength and blocking resistance. can be expressed.
[0035]
The method for polymerizing ethylene and unsaturated carboxylic acid is not particularly limited, and known polymerization methods can be employed. Examples of polymerization methods include a method of contacting ethylene, an unsaturated carboxylic acid, and a known polymerization initiator such as a peroxide under conditions of high temperature and high pressure.
[0036]
The ethylene/unsaturated carboxylic acid copolymer (b1) can be obtained as a dispersion (aqueous dispersion) in which individual particles (hereinafter referred to as resin particles (I)) are dispersed in water. In such cases, for example, JP-B-7-008933, JP-B-5-039975, JP-B-4-030970, JP-B-42-000275, JP-B-42-023085, JP-B-45 -029909, JP-A-51-062890 and the like can be used for polymerization. The ethylene/unsaturated carboxylic acid copolymer (b1) has self-emulsifiability.
[0037]
In the production of the ethylene/unsaturated carboxylic acid copolymer (b1), from the viewpoint of improving production stability, an emulsifier (surfactant), which will be described later, can be blended as needed. The mixing ratio of the emulsifier is appropriately set.
[0038]
In the production of the ethylene/unsaturated carboxylic acid copolymer (b1), from the viewpoint of improving production stability, for example, pH adjusters, metal ion sequestering agents such as ethylenediaminetetraacetic acid and salts thereof, For example, known additives such as molecular weight modifiers (chain transfer agents) such as mercaptans and low-molecular-weight halogen compounds can be blended in appropriate proportions.
[0039]
As the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1), the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) is used from the viewpoint of improving the dispersion stability and the printability of the laminate (described later). Salts (B1) of copolymers (b1) are preferred.
[0040]
The salt (B1) of the ethylene/unsaturated carboxylic acid copolymer (b1) is, for example, the ethylene/unsaturated carboxylic acid copolymer (b1), specifically the ethylene/unsaturated carboxylic acid copolymer It can be prepared by adding a base to the dispersion of coalescence (b1).
[0041]
Examples of bases include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as amines such as ammonia, triethylamine, triethanolamine, and dimethylethanolamine.
[0042]
These bases may be used singly or in combination of two or more.
The base preferably includes an inorganic base, more preferably sodium hydroxide.
[0043]
From the viewpoint of improving the dispersion stability and the printability of the laminate (described later), the amount of the base added (that is, the amount of substance/valence) is adjusted to the carboxy group in the ethylene/unsaturated carboxylic acid copolymer (b1). For 100 mol, it is, for example, 5 mol or more, preferably 30 mol or more, more preferably 50 mol or more, and for example, 100 mol or less, preferably 95 mol or less.
[0044]
When the amount of the base added is at least the above lower limit, the dispersion stability of the aqueous dispersion is excellent, and the printability of the laminate is excellent. Moreover, when the amount of the base to be added is equal to or less than the above lower limit, the viscosity of the aqueous dispersion is not too high and the workability is excellent.
[0045]
Further, after the base is added to the ethylene/unsaturated carboxylic acid copolymer (b1), they are preferably kept at a predetermined temperature for a predetermined time. The holding temperature is, for example, 40° C. or higher, preferably 50° C. or higher, and for example, 190° C. or lower, preferably 180° C. or lower. The retention time is, for example, 30 minutes or longer, preferably 1 hour or longer, and is, for example, 12 hours or shorter, preferably 10 hours or shorter.
[0046]
By maintaining the above conditions, the ethylene/unsaturated carboxylic acid copolymer (b1) is neutralized, and the dispersion stability and the printability of the laminate (described later) can be improved.
When the ethylene/unsaturated carboxylic acid copolymer (B1) is a salt of the ethylene/unsaturated carboxylic acid copolymer (b1), the degree of neutralization is, for example, 30% or more, preferably 50%. For example, it is 100% or less, preferably 95% or less.
[0047]
If the degree of neutralization is within the above range, excellent adhesive strength and blocking resistance can be obtained. In addition, the degree of neutralization is calculated according to the method employed in the examples described later.
　Measure the infrared absorption spectrum of the sample and determine the peak height of the absorption at 1700 cm -1 corresponding to the carboxy group (the peak height is defined as a).
[0048]
In addition, the sample is brought into contact with hydrochloric acid to remove the metal ions in the resin (demetalization) to obtain an acid copolymer without ionic bonding (intramolecular cross-linking). The infrared absorption spectrum of a sample of this acid copolymer is measured, and the peak height of absorption at 1700 cm -1 is obtained (the peak height is defined as b).
[0049]
The peak height a corresponds to the number of carboxyl groups that are not ionically bonded in the resin.
Also, the peak height b corresponds to the number of all carboxyl groups in the resin.
Therefore, the degree of neutralization (%) is calculated using the following formula.
　　Neutralization degree (%) = 100-100 x a/b
[0050]
The weight-average molecular weight of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or salt thereof (B1) is, for example, 5,000 or more in terms of standard polystyrene by gel permeation chromatography (GPC) measurement, preferably It is 10,000 or more, for example, 1,000,000 or less, preferably 500,000 or less.
[0051]
The melting point of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or salt thereof (B1) measured by DSC (differential scanning calorimetry) is, for example, 55° C. or higher, preferably 65° C. or higher, For example, it is 110° C. or lower, preferably 100° C. or lower.
[0052]
The solid content concentration of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or salt thereof (B1) in the dispersion of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or salt thereof (B1) is , for example, 10% by mass or more, preferably 20% by mass or more, and for example, 60% by mass or less, preferably 50% by mass or less.
[0053]
The dispersion of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) can also be obtained as a commercial product.
These ethylene/unsaturated carboxylic acid copolymers and/or salts thereof (B1) may be used singly or in combination of two or more.
[0054]
From the viewpoint of improving the frictional resistance retention of the resulting laminate, the dispersion of the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) may be an ethylene/acrylic acid copolymer ( A mixture of b1-1) and/or a salt thereof (B1-1) and an ethylene/methacrylic acid copolymer (b1-2) and/or a salt thereof (B1-2) is also a preferred embodiment. The detailed mechanism for improving the frictional resistance retention rate is unknown, but when the mixture is dispersed in water, the polymer particles containing the polymer component become finer, and the film formation performance improves. It is presumed that some kind of contribution is made.
[0055]
<(Meth) acrylic acid ester polymer (B2)>
The (meth)acrylic acid ester polymer (B2) includes, as a structural unit, at least a structural unit obtained from (meth)acrylic acid ester ((meth)acrylic acid ester monomer) (hereinafter "(meth)acrylic acid ester unit" are also described.).
[0056]
(Meth)acrylic acid ester is defined as acrylic acid ester and/or methacrylic acid ester.
Examples of the (meth)acrylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and iso-butyl (meth)acrylate. , s-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc., having an alkyl moiety of 1 to 12 carbon atoms ( meth)acrylic acid esters.
[0057]
These (meth)acrylic acid esters may be used singly or in combination of two or more.
The (meth)acrylic acid esters preferably include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, and t (meth)acrylate. -Butyl and 2-ethylhexyl (meth)acrylate, more preferably methyl (meth)acrylate and n-butyl (meth)acrylate, still more preferably methyl methacrylate and methacrylic acid Examples include n-butyl and butyl acrylate.
[0058]
In addition, the polymer (B2) may contain, as an optional component, a polymerized unit obtained from a copolymerizable monomer that can be copolymerized with the (meth)acrylic acid ester.
Examples of the copolymerizable monomer include functional group-containing vinyl monomers, aromatic vinyl monomers, N-substituted unsaturated carboxylic acid amides, heterocyclic vinyl compounds, vinylidene halide compounds, α-olefins, and dienes. be done.
[0059]
Functional group-containing vinyl monomers include, for example, carboxy group-containing vinyl monomers, hydroxyl group-containing vinyl monomers, amino group-containing vinyl monomers, glycidyl group-containing vinyl monomers, cyano group-containing vinyl monomers, sulfonic acid group-containing vinyl monomers and salts thereof, aceto Examples include acetoxy group-containing vinyl monomers, phosphoric acid group-containing compounds, amide group-containing vinyl monomers, and vinyl esters.
[0060]
Examples of carboxy group-containing vinyl monomers include (meth)acrylic acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, and crotonic acid.
Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.
[0061]
Examples of amino group-containing vinyl monomers include 2-aminoethyl (meth)acrylate, 2-(N-methylamino)ethyl (meth)acrylate, and 2-(N,N-dimethylamino) (meth)acrylate. and ethyl.
[0062]
Examples of glycidyl group-containing vinyl monomers include glycidyl (meth)acrylate.
Examples of cyano group-containing vinyl monomers include (meth)acrylonitrile.
[0063]
　Sulfonic acid group-containing vinyl monomers include, for example, allylsulfonic acid and methallylsulfonic acid. Examples of salts thereof include alkali metal salts such as sodium salts and potassium salts, such as ammonium salts, of the above sulfonic acid group-containing vinyl monomers. Specifically, for example, sodium methallylsulfonate, sodium methallylsulfonate, and ammonium methallylsulfonate;
[0064]
Examples of acetoacetoxy group-containing vinyl monomers include acetoacetoxyethyl (meth)acrylate.
Examples of phosphate group-containing compounds include 2-methacryloyloxyethyl acid phosphate.
[0065]
Examples of amide group-containing vinyl monomers include (meth)acrylamide.
Examples of vinyl esters include vinyl propionate (excluding vinyl acetate).
[0066]
Examples of aromatic vinyl monomers include styrene, α-methylstyrene, and divinylbenzene.
Examples of N-substituted unsaturated carboxylic acid amides include N-methylol(meth)acrylamide.
[0067]
Examples of heterocyclic vinyl compounds include vinylpyrrolidone.
Examples of vinylidene halide compounds include vinylidene chloride and vinylidene fluoride.
[0068]
Examples of α-olefins include ethylene and propylene.
Examples of dienes include butadiene.
Furthermore, a crosslinkable vinyl monomer can also be mentioned as a copolymerizable monomer.
[0069]
Examples of crosslinkable vinyl monomers include compounds containing two or more vinyl groups, such as methylenebis(meth)acrylamide, divinylbenzene, and polyethylene glycol chain-containing di(meth)acrylate.
[0070]
These copolymerizable monomers may be used singly or in combination of two or more.
The copolymerizable monomer preferably includes a functional group-containing vinyl monomer.
In addition, as the (meth)acrylic acid ester, methacrylic acid ester is preferable among acrylic acid esters and methacrylic acid esters from the viewpoint of water resistance.
[0071]
The content of structural units derived from (meth)acrylic acid ester units and other copolymerizable monomers (hereinafter also referred to as “copolymerizable monomer units”) in the polymer (B2) is the total of 100 In terms of % by mass, the (meth)acrylate unit is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 77% by mass or more. Also, the copolymerizable monomer unit is 50% by mass or less, preferably 30% by mass or less, more preferably 23% by mass or less.
[0072]
If the content ratio of the (meth)acrylic acid ester unit and the copolymerizable monomer unit is within the above range, excellent adhesive strength and blocking resistance can be obtained.
That is, the polymer (B2) may be composed only of (meth)acrylic acid ester units without containing copolymerizable monomer units, and the (meth)acrylic acid ester component and It may also consist of a copolymerizable monomer component. The polymer (B2) preferably consists of (meth)acrylic acid ester units only, or consists of (meth)acrylic acid ester units and copolymerizable monomer units in the above ratio.
[0073]
When the polymer (B2) consists only of (meth)acrylic acid ester units, the (meth)acrylic acid ester preferably consists only of a (meth)acrylic acid ester having an alkyl moiety having 4 carbon atoms, or , a combination of methyl (meth)acrylate and a (meth)acrylic acid ester having an alkyl moiety of 4 carbon atoms.
[0074]
When the (meth)acrylic acid ester consists only of a (meth)acrylic acid ester having an alkyl moiety having 4 carbon atoms, the (meth)acrylic acid ester particularly preferably consists only of n-butyl methacrylate, or It consists of a combination of n-butyl methacrylate and n-butyl acrylate.
[0075]
Further, when the (meth)acrylic acid ester is a combination of methyl (meth)acrylate and a (meth)acrylic acid ester having an alkyl moiety having 4 carbon atoms, the (meth)acrylic acid ester is particularly preferably , a combination of methyl methacrylate and n-butyl methacrylate, or a combination of methyl methacrylate and n-butyl acrylate.
[0076]
With such a combination of (meth)acrylic acid esters, the glass transition temperature of the polymer (B2) can be adjusted within the range described below.
Further, when the other copolymerizable monomer is a carboxy group-containing vinyl monomer, the ratio of structural units derived from the carboxy group-containing vinyl monomer in the polymer (B2) is, for example, 5 from the viewpoint of production stability. % by mass or less, preferably 3% by mass or less.
[0077]
The method for producing the polymer (B2) is not particularly limited, and known production methods can be employed. An example of the production method includes a method of mixing water, a (meth)acrylic acid ester component and a polymerization initiator, and polymerizing the (meth)acrylic acid ester component in water.
[0078]
The polymerization initiator is not particularly limited, but for example
hydrogen peroxide;
Persulfates such as ammonium persulfate, potassium persulfate, sodium persulfate;
Organic peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxybenzoate, lauroyl peroxide; and
azo compounds such as azobisisobutyronitrile, and
Examples of redox initiators include combinations of these with metal ions such as iron ions and reducing agents such as sodium sulfoxylate, formaldehyde, sodium pyrosulfite, sodium hydrogen sulfite, L-ascorbic acid, and Rongalite. These polymerization initiators may be used singly or in combination of two or more.
[0079]
The blending ratio of the polymerization initiator is appropriately set, but is, for example, 0.1% by mass or more and, for example, 5% by mass or less with respect to the total amount of the monomer components.
In addition, in polymerization, a molecular weight modifier can be blended as needed.
[0080]
Examples of molecular weight modifiers include mercaptans such as t-dodecylmercaptan and n-dodecylmercaptan, allyl compounds such as allylsulfonic acid, methallylsulfonic acid and their soda salts. These molecular weight modifiers may be used singly or in combination of two or more. The mixing ratio of the molecular weight modifier is appropriately set.
[0081]
When polymerizing under normal pressure, the polymerization temperature is, for example, 30°C or higher, preferably 50°C or higher, and for example, 95°C or lower, preferably 85°C or lower. The polymerization time is, for example, 1 hour or more, preferably 2 hours or more, and for example, 30 hours or less, preferably 20 hours or less.
[0082]
In addition, in the production of the polymer (B2), an emulsifier (surfactant) can be blended as necessary from the viewpoint of improving production stability.
Examples of emulsifiers (surfactants) include anionic surfactants, nonionic surfactants, and cationic surfactants.
[0083]
Examples of anionic surfactants include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyldiphenyletherdisulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium stearate, potassium oleate, and sodium dioctylsulfosuccinate. , sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkylphenyl ether sulfate, sodium dialkyl sulfosuccinate, sodium stearate, sodium oleate, t-octylphenoxyethoxypolyethoxyethyl sulfate sodium salt mentioned.
[0084]
Nonionic surfactants include, for example, polyoxyethylene lauryl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleylphenyl ether, polyoxyethylene nonylphenyl ether, oxyethylene/oxypropylene block copolymer, t-octylphenoxy ethylpolyethoxyethanol, nonylphenoxyethylpolyethoxyethanol.
[0085]
Examples of cationic surfactants include lauryltrimethylammonium chloride and stearyltrimethylammonium chloride.
These emulsifiers (surfactants) may be used singly or in combination of two or more.
[0086]
The emulsifier (surfactant) is preferably an anionic surfactant, more preferably sodium dodecylbenzenesulfonate.
The blending ratio of the emulsifier (surfactant) is not particularly limited. 02 parts by mass or more, for example, 5 parts by mass or less.
[0087]
In the production of the polymer (B2), from the viewpoint of improving the production stability, for example, pH adjusters, metal ion sequestering agents such as ethylenediaminetetraacetic acid and salts thereof, mercaptans, low molecular weight Known additives such as molecular weight modifiers (chain transfer agents) such as halogen compounds can be blended in appropriate proportions.
[0088]
The weight average molecular weight of the polymer (B2) is, for example, 5,000 or more, preferably 10,000 or more, for example, 1,000,000 or less, preferably 500,000, in terms of standard polystyrene measured by gel permeation chromatography (GPC). It is below.
[0089]
The glass transition temperature of the polymer (B2) is, for example, -28°C or higher, preferably -10°C or higher, and for example, 80°C or lower, preferably 60°C or lower. If the glass transition temperature of the polymer (B2) is within the above range, excellent adhesive strength and blocking resistance can be obtained.
[0090]
In particular, from the viewpoint of improving the adhesive strength of the aqueous dispersion, the glass transition temperature of the polymer (B2) is preferably 20°C or lower, more preferably 10°C or lower.
In addition, from the viewpoint of improving the blocking resistance of the aqueous dispersion, the glass transition temperature of the polymer (B2) is preferably above 0°C, more preferably 10°C or higher.
[0091]

The amide wax (C) is a compound having a long-chain fatty acid group and an amide group in its molecule.
[0092]
Examples of the amide wax (C) include an amide compound obtained by reacting a monocarboxylic acid and a monoamine, or a monocarboxylic acid and a diamine, an amide compound obtained by reacting a monoamine and a polybasic acid, and An amide compound obtained by reacting a monocarboxylic acid, a polybasic acid and a diamine can be mentioned.
[0093]
As the monoamine, monoamines having 5 or more carbon atoms are preferable, and examples include pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, stearylamine, cyclohexylamine, and benzylamine. These may be used singly or in combination of two or more. Among them, aliphatic monoamines having 10 to 20 carbon atoms are particularly preferred.
[0094]
The monocarboxylic acid is preferably an aliphatic monocarboxylic acid having 5 or more carbon atoms and a hydroxycarboxylic acid. acid, montanic acid, 12-hydroxystearic acid, benzoic acid and the like. These may be used singly or in combination of two or more. Among them, aliphatic monocarboxylic acids having 10 to 30 carbon atoms are particularly preferred.
[0 095]
Specific examples of the diamine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylenediamine, p-xylylenediamine, tolylenediamine, phenylenediamine, isophoronediamine and the like. These may be used singly or in combination of two or more. Among them, ethylenediamine is particularly suitable.
[0096]
The polybasic acid is a dibasic or higher carboxylic acid, and specific examples thereof include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, sebacic acid, pimelic acid, and azelaic acid, phthalic acid, and terephthalic acid. acids, aromatic dicarboxylic acids such as isophthalic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and cyclohexylsuccinic acid. These may be used singly or in combination of two or more.
[0097]
Specific examples of the amide wax (C) include N-oleyl palmitoamide, ethylenebisoleic acid amide, and N-stearyl erucic acid amide.
[0098]

The aqueous dispersion of the present invention may contain polymers (ethylene-vinyl acetate copolymers, etc.) or additives other than the above components (A), (B) and (C).
[0099]
Additives include, for example, the above-described emulsifiers, curing agents, cross-linking agents, film-forming aids, defoaming agents, anti-cratering agents, leveling agents, tackifiers, hardness-imparting agents, preservatives, thickeners, Known additives such as antifreeze agents, dispersants, inorganic pigments and organic pigments can be used. These additives may be used singly or in combination of two or more. The blending ratio and blending timing of the additive are appropriately set according to the purpose and application.
[0100]

The aqueous dispersion of the present invention is a dispersion containing the polyolefin (A), the unsaturated carboxylic acid polymer (B), the amide wax (C), and water. It is appropriately set according to the application.
[0101]
When the total amount of polyolefin (A) and unsaturated carboxylic acid polymer (B) is 100% by mass, the content of polyolefin (A) in the aqueous dispersion of the present invention is, for example, 30% by mass or more, preferably 45% by mass. % by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, for example 70% by mass or less, preferably 65% ​​by mass or less, more preferably 60% by mass or less.
[0102]
When the total amount of polyolefin (A) and unsaturated carboxylic acid polymer (B) is 100% by mass, the content of unsaturated carboxylic acid polymer (B) in the aqueous dispersion of the present invention is, for example, 30% by mass. Above, preferably 35% by mass or more, more preferably 40% by mass or more, for example, 70% by mass or less, preferably 55% by mass or less, more preferably 50% by mass or less, further preferably 40% by mass or less.
[0103]
When the content ratio of the polyolefin (A) and the unsaturated carboxylic acid polymer (B) is within the above range, excellent adhesive strength can be obtained, and the effect of adding the amide-based wax can be readily exhibited.
[0104]
The amount of the amide wax (C) contained in the aqueous dispersion of the present invention is 0.15 to 3.0 parts per 100 parts by mass of the component (A) + the component (B) in the aqueous dispersion. Parts by mass, preferably 0.15 to 2.5 parts by mass, more preferably 0.2 to 2.0 parts by mass.
[0105]
The solid content of the aqueous dispersion is the components other than water and the organic solvent (which may be included as an optional ingredient) among the components contained in the aqueous dispersion of the present invention.
[0106]

As a method for producing the aqueous dispersion of the present invention, the above components are mixed at the above predetermined ratio and emulsified at once, and after emulsifying the individual components, they are mixed at the above predetermined ratio. method.
[0107]
In addition, the aqueous dispersion of the present invention may contain the above polymer components (that is, polyolefin (A) and component (B)) as non-particulate polymers, or may contain particulate polymer components. It may be contained as a coalescence. Preferably, the polymer component is contained as particulate polymer.
[0108]
The weight average particle diameter of the particles (measurement method: light scattering measurement) is, for example, 10 nm or more, for example, 10 μm or less, preferably 5 μm or less.
When the polymer component is contained in the aqueous dispersion as a particulate polymer, the polymer component may be a single particle of each polymer, or may be a composite particle composed of two or more types of polymers. There may be.
[0109]
For example, the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) and the (meth)acrylic acid ester polymer (B2) may form composite particles.
A method for producing such composite particles is not particularly limited, and a known method can be adopted.
[0110]
The morphology of the composite particles is not particularly limited, and examples thereof include core/shell structures, composite structures, localized structures, daruma-like structures, octopus-like structures, raspberry-like structures, multi-particle composite structures, and IPN structures.
[0111]
The solid content concentration of the aqueous dispersion of the present invention is, for example, 10% by mass or more, preferably 20% by mass or more, and is, for example, 60% by mass or less, preferably 50% by mass or less.
The pH of the aqueous dispersion of the present invention is, for example, 7 or more, preferably 10 or less, for example 11 or less, preferably 10 or less.
[0112]
The aqueous dispersion of the present invention can rapidly exhibit low friction properties after being applied to a base material.
By using the aqueous dispersion of the present invention to form an adhesive layer (heat seal layer) of a laminate, a laminate having excellent adhesive strength can be obtained.
[0113]
Therefore, the aqueous dispersion is suitably used as an adhesive composition for forming an adhesive layer in a laminate comprising a substrate and an adhesive layer laminated on at least one surface of the substrate. be able to.
[0114]

The laminate of the present invention comprises a substrate and an adhesive layer laminated on at least part of at least one surface of the substrate.
[0115]
Examples of base materials include resin base materials, metal base materials, and composite base materials.
Examples of resin substrates include cellophane, polyethylene, ethylene/vinyl acetate copolymer, ionomer, polypropylene, polyamide (nylon), polyester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene/vinyl alcohol copolymer, Examples include plastic films, containers, and cups made of plastic materials such as polycarbonate, polystyrene, and polyacrylonitrile copolymers.
[0116]
Examples of metal substrates include metal plates, metal foils, containers, and cups, and examples of metals include aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, and chromium.
[0117]
As the composite substrate, for example, a metal (aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, chromium, etc.) or an oxide thereof (aluminum oxide, silicon oxide, etc.) is deposited on the plastic film. Vapor-deposited films may be mentioned.
[0118]
Furthermore, examples of base materials include paper and non-woven fabrics.
These base materials may be used singly or in combination of two or more.
The base material preferably includes a metal base material, more preferably a metal base material made of aluminum, and still more preferably a metal foil made of aluminum.
[0119]
The base material may be surface-treated as necessary. Examples of the surface treatment include ink (solvent-based, water-based) coating treatment, plating treatment, coupling treatment, vacuum plasma treatment, etc., preferably ink coating treatment, more preferably solvent-based ink coating. processing.
[0120]
The adhesive layer is a dried product of the above water dispersion, and can be obtained by coating (coating) the above water dispersion on one side surface of the substrate and drying.
The aqueous dispersion may be applied to the entire surface of one side of the substrate, or if the aqueous dispersion is used to form a heat seal layer, the one side surface of the substrate may be laminated. It is sufficient that the adhesive is applied to the portion where the laminated body and other material are heat-sealed (adhered).
[0121]
The method of applying (coating) the water dispersion is not particularly limited, and known methods such as gravure roll coating, three-roll coating, dip coating, and spray coating are employed.
Further, when drying the coating film of the applied water dispersion, the drying temperature is, for example, 100 to 200° C., and the drying time is, for example, 10 seconds to 30 minutes.
[0122]
Before coating and drying, a primer (titanate, polyethyleneimine, etc.) may be applied to the substrate in order to improve the adhesion between the substrate and the adhesive layer. Pretreatment such as discharge treatment or chemical conversion treatment may be performed.
[0123]
According to such a laminate, since the water dispersion is used in the heat seal layer (adhesive layer), excellent adhesive strength and low friction properties can be obtained. Further, since the aqueous dispersion of the present invention is not a dispersion in which particles are dispersed in an organic solvent such as ethyl acetate or toluene, the amount of residual organic solvent in the adhesive layer is preferably 100 ppm or less, more preferably It can be 10 ppm or less.
[0124]
Therefore, the laminate of the present invention is used as a heat-sealing material in various industrial fields.
At the time of heat sealing, the base material and the adherend layer are attached via an adhesive layer.
[0125]
The adherend layer is a material to which the laminate is adhered, and examples thereof include resin materials, metal materials, and composite materials.
Examples of resin materials include cellophane, polyethylene, ethylene/vinyl acetate copolymer, ionomer, polypropylene, polyamide (nylon), polyester, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene/vinyl alcohol copolymer, and polycarbonate. , polystyrene, and polyacrylonitrile copolymer.
[0126]
Examples of metal materials include metal plates and metal foils, and examples of metals include aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, and chromium.
[0127]
As a composite material, for example, a metal (aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, chromium, etc.) or its oxide (aluminum oxide, silicon oxide, etc.) is deposited on the plastic film. vapor-deposited films.
[0128]
Furthermore, examples of the adherend layer include paper and nonwoven fabric.
In addition, the adherend layer may be surface-treated as necessary. Examples of the surface treatment include ink (solvent-based, water-based) coating treatment, plating treatment, coupling treatment, and vacuum plasma treatment, preferably ink coating treatment, more preferably solvent-based ink coating treatment. is mentioned.
[0129]
The adherend layer also includes a laminate comprising a substrate and an adhesive layer.
These adherend layers may be used singly or in combination of two or more.
From the viewpoint of adhesion strength and ease of adhesion, the adherend layer is preferably a plastic film made of polyvinyl chloride or polyvinylidene chloride.
[0130]
The method for heat-sealing the base material and the adherend layer is not particularly limited, and a known method is adopted. For example, a method of laminating a base material and an adherend layer via an adhesive layer, followed by heating and pressing can be mentioned. In addition, when the laminate of the present invention is used as the adherend layer, the adhesive layers are laminated to each other, and two substrates are laminated via the two adhesive layers, heated and pressed. be done.
[013 1]
The heating temperature is, for example, 80°C or higher, preferably 100°C or higher, and is, for example, 250°C or lower, preferably 200°C or lower. Also, the pressure is, for example, 50 kPa or more, preferably 100 kPa or more, and for example, 500 kPa or less, preferably 300 kPa or less.
[0132]
As a result, the substrate and the adherend layer are heat-sealed (thermocompression bonded).
The adhesive strength between the base material and the adherend layer can be measured by the peel strength between the base material and the adherend layer.
The laminated body in which the adherend layer is laminated on one side surface of the adhesive layer in this manner is included in the present invention regardless of its heat-sealed state (that is, before and after heat-sealing).
[0133]
And, since such a laminate is obtained using the above water dispersion, it is excellent in low-friction properties.
Furthermore, such a laminate has excellent adhesive strength.
[0134]
Therefore, laminates are suitably used as packaging materials in various industrial fields.
The items to be packaged with the laminate are not particularly limited, and examples include various industrial products such as sweets, foods, daily necessities, medicines, and papers.
[0135]
In particular, in the pharmaceutical and food packaging fields, it is expected to have effects such as suppressing the deterioration of packaging materials and packaged items during heat sealing, and improving productivity and reducing power consumption by increasing the filling speed. . Moreover, since the adhesive composition for forming the adhesive layer is an aqueous dispersion, it has the advantage of having a small environmental load.
Example
[0136]
The present invention will be described in detail below with examples and comparative examples, but the present invention is not limited to these.
[0137]
[Evaluation method]
The aqueous dispersions and laminates produced in Examples, etc. were evaluated by the following methods.
[0138]

The particle size of the solid content in the water dispersions produced in the examples, etc. was measured using a laser diffraction/scattering particle size distribution measuring device Microtrac series.
[0139]

The coefficient of dynamic friction (COF) of the coating film possessed by the laminate manufactured in Examples etc. was measured using a friction measuring machine TR-2 (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the coating film surfaces were moved at a speed of 100 mm / min. It was measured by
[0140]
In addition, the dynamic friction coefficient retention rate was calculated using the following formula.
Dynamic friction coefficient retention rate (%) = (dynamic friction coefficient of dry coating film after elapse of predetermined time from laminate production/dynamic friction coefficient of dry coating film immediately after laminate production) x 100

After leaving the laminates produced in Examples and the like at room temperature for a day and night, they were cut into strips of 15 mm width, and the dried coating films were superposed on each other and heated for 0.5 seconds at a temperature of 110° C. and a pressure of 2 kgf/cm 2 . A test piece was obtained by sealing. Using the obtained test piece, the 180 degree peel strength was measured under the condition of a tensile speed of 200 mm/sec.
[0141]
[Example 1]

Using the kneading apparatus described in FIG. 1 of JP-A-63-46273, high-pressure low-density polyethylene (manufactured by Mitsui Dow Polychemicals Co., Ltd., trade name: Milathon FL60, hereinafter referred to as polyolefin (A)) was prepared. Also referred to as "LDPE". ] and an ethylene-acrylic acid copolymer as the unsaturated carboxylic acid polymer (B) [Mitsui Dow Polychemicals Co., Ltd., trade name: Nucrel (ethylene content: 72% by mass), hereinafter also referred to as “EAA” Describe. ] were put into a hopper of a kneading device at a weight ratio of 5/5, and melt-kneaded. During melt-kneading, an aqueous solution of potassium hydroxide was introduced into the kneader so that the degree of neutralization of the acrylic acid units in the ethylene/acrylic acid copolymer was 50%, thereby neutralizing the acrylic acid component. After that, water and N-oleyl palmitamide, which is an amide wax, is supplied in an amount of 0.3 parts by mass based on the total amount of 100 parts by mass of the resin component as wax into the kneader, and the mixture in the kneader was cooled to room temperature, and finally water was further added to obtain an aqueous dispersion having a solid content concentration of 40% by mass.
The particle size of the solid content in the obtained aqueous dispersion was 2 μm.
[0142]

After adding deionized water to the obtained aqueous dispersion to adjust the solid content concentration to 24%, the entire surface of one surface of an aluminum foil (thickness: 40 μm) was coated with a coating amount of 3 g. /m 2 and dried at 120°C for 30 seconds to obtain a laminate consisting of a soft aluminum foil and a dry coating film of the aqueous dispersion.
[0143]
[Examples 2 to 5]
The amount of amide-based wax during the production of the aqueous dispersion was changed to 0.5 parts by mass, 1.0 parts by mass, 1.5 parts by mass, and 2.0 parts by mass, respectively, with respect to the total amount of 100 parts by mass of the resin component. Three aqueous dispersions of Examples 2 to 5 (each particle size was 2 μm) were obtained by performing the same operation as in Example 1 except that Then, using these aqueous dispersions, laminates of Examples 2 to 5 were obtained in the same manner as in Example 1.
[0144]
1 to 3 show the measurement results of the dynamic friction coefficients of the laminates of Examples 1 to 5, and Table 1 shows the evaluation results of the heat sealability of Example 1.
[0145]
[Comparative example 1]
A water dispersion of Comparative Example 1 was obtained in the same manner as in Example 1, except that no wax was added. A laminate of Comparative Example 1 was produced in the same manner as the laminate of Example 1 using the aqueous dispersion.
Fig. 1 shows the measurement results of the dynamic friction coefficient of the laminate.
[0146]
[Example 6]
In the same manner as in Example 1, except that the wax was changed to ethylene bis oleic acid amide, which is an amide wax, and the concentration of the wax was only 0.3 parts by mass with respect to the total amount of 100 parts by mass of the resin component. , to obtain the aqueous dispersion of Example 6. Next, a laminate of Example 6 was obtained in the same manner as in Example 1 using the aqueous dispersion. The particle size of the solid content in the aqueous dispersion was 2 μm.
　Figures 2 and 3 show the measurement results of the dynamic friction coefficient of the laminate.
[0147]
[Comparative Examples 2-5]
The wax was changed to polyethylene wax (manufactured by Mitsui Chemicals, Inc., trade name: W200), and the concentration of the wax was changed to 0.5 parts by mass, 1.0 parts by mass, and 1.5 parts by mass with respect to the total amount of the resin component. Aqueous dispersions of Comparative Examples 2 to 5 were obtained in the same manner as in Example 1 except that the amount was 2.0 parts by mass. Then, laminates of Comparative Examples 2 to 5 were obtained in the same manner as in Example 1 using these aqueous dispersions.
The particle size of the solid content in the aqueous dispersions of Comparative Examples 2 to 5 was all 2 μm. FIG. 1 shows the measurement results of the dynamic friction coefficient of the laminate.
[0148]
[Comparative example 6]
Ethylene/methacrylic acid copolymer [manufactured by Dow Mitsui Polychemicals, trade name: Nucrel (ethylene content 85% by mass), hereinafter also referred to as "EMAA". ], potassium hydroxide, water, and N-oleyl palmitoamide (0.3% by mass of the total amount of the resin components) were charged into an autoclave and subjected to a temperature condition of 130° C. to 180° C. and pressure conditions for 4 hours. Stirred for ~8 hours. After that, the mixture was cooled to room temperature to obtain an aqueous dispersion of Comparative Example 6 having a solid content concentration of 42% by mass and having a good dispersion state. Next, a laminate of Comparative Example 6 was obtained using the aqueous dispersion. The particle size of the solid content in the water dispersion was 2.0 μm.
[0149]
　Figures 2 and 3 show the measurement results of the dynamic friction coefficient of the laminate, and Table 1 shows the evaluation results of the heat sealability.
[0150]
[table 1]

When the heat seal strength was 2.5 N/15 mm or more, it was judged as OK.
[0151]
[Examples 7 to 16, Comparative Examples 7 and 8]
Aqueous dispersions of Examples 7 to 16 and Comparative Examples 7 and 8 were prepared in the same manner as in Example 1 except that the composition of the aqueous dispersion was changed to the composition shown in Table 2 below. Then, using these, laminates of Examples 7 to 16 and Comparative Examples 7 and 8 were obtained. In Table 2, l-LDPE is Prime Polymer's Evolue SP0540, ethylene-butene copolymer is Mitsui Chemicals Co., Ltd. Toughmer DF7350, ethylene-acrylic acid copolymer is Mitsui Dow Polychemicals Co., Ltd. Nucrel (ethylene-containing ratio: 72% by mass), ethylene-methacrylic acid copolymer 1 is Nucrel manufactured by Mitsui Dow Polychemical Co., Ltd. (ethylene content: 91% by mass), ethylene-methacrylic acid copolymer 2 is Mitsui Dow Polychemical Nucrel Co., Ltd. (ethylene content: 85% by mass) was used.
[0152]
[Table 2]

[0153]
For each laminate obtained, the coefficient of dynamic friction (initial COF) immediately after production of the laminate, the coefficient of dynamic friction (COF after 3 hours) after 3 hours of production of the laminate, and the retention of the coefficient of dynamic friction (3 hours after production of the laminate) (3 COF retention after time) and heat seal strength were obtained in the same manner as in Example 1. Table 2 shows the results. As a comprehensive judgment, an initial COF of 0.28 or less and a COF retention rate after 3 hours of 50% or more were judged as OK, and other cases were judged as NG.
[0154]

Fig. 1 shows the amount of polyethylene wax and amide wax added and the effect on the coefficient of dynamic friction (immediately after coating). From FIG. 1, it can be seen that the water dispersion of Example 1, in which amide wax was used, has a smaller coefficient of dynamic friction than the water dispersion of Comparative Example 6, in which polyethylene wax was used as wax.
[0155]
Fig. 2 shows the relationship between the standing time after application of the water dispersion and the dynamic friction coefficient. From FIG. 2, the aqueous dispersions of Examples 1 and 6 (resin component: LDPE/EAA = 5/5 (wax amount: 0.3 parts by mass)) are the same as the aqueous dispersions of Comparative Example 6 (resin component: EMAA = It can be seen that a lower coefficient of dynamic friction was exhibited in a short time after coating compared to 100% (amount of wax: 0.3 parts by mass).
[0156]
Fig. 3 shows the relationship between the standing time after coating of the aqueous dispersion and the retention rate of the dynamic friction coefficient. From FIG. 3, the dynamic friction coefficient retention rate of the dry coating films formed from the aqueous dispersions of Examples 1 and 6 after 3 hours from coating (that is, from the production of the laminate) is about 80%. On the other hand, the dry coating film formed from the aqueous dispersion of Comparative Example 6 had a retention rate of 40%, indicating that the dynamic friction coefficient varied greatly depending on the standing time after coating.
[0157]
From the heat seal strength results of Examples 8 to 16 in Table 2, it can be seen that the combined use of two types of polyolefin (A) in the present invention can improve the heat seal strength at low temperatures.
The scope of the claims
[Claim 1]
Aqueous dispersion containing polyolefin (A), unsaturated carboxylic acid polymer (B), amide wax (C) and water.
[Claim 2]
2. The aqueous dispersion according to claim 1, wherein the concentration of the amide wax (C) is 0.15 to 3 with respect to component (A)+component (B) of the aqueous dispersion=100 parts by mass. .0 parts by weight of water dispersion.
[Claim 3]
The unsaturated carboxylic acid polymer (B) is selected from the group consisting of an ethylene/unsaturated carboxylic acid copolymer (b1) and/or a salt thereof (B1), and a (meth)acrylic acid ester polymer (B2). The aqueous dispersion according to claim 1 or 2, which is at least one kind of.
[Claim 4]
The unsaturated carboxylic acid polymer (B) is a composite particle containing the ethylene/unsaturated carboxylic acid copolymer (b1) and/or its salt (B1) and the acrylic acid ester polymer (B2). Aqueous dispersion according to any one of claims 1 to 3.
[Claim 5]
A substrate and an adhesive layer laminated on at least part of at least one surface of the substrate, wherein the adhesive layer is the water dispersion according to any one of claims 1 to 4. A laminate made of dried matter.
[Claim 6]
The laminate according to claim 5, further comprising an adherend layer laminated on the surface of the adhesive layer opposite to the substrate side.
[Claim 7]
The laminate according to claim 5 or 6, wherein the base material is made of aluminum.