Description:TECHNICAL FIELD
[0001] The present disclosure relates to technical field of adhesives, and in particular to a liquid epoxy composition useful as adhesive.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Sealant is a sealing material that bonds the surfaces of the same or different solid materials together, or is used to fill gaps in materials to seal. It has a certain adhesiveness. It is an adhesive that has the functions of preventing leakage, waterproofing, anti-vibration, heat insulation, sound insulation and other functions.
[0004] Sealants are widely used in aerospace, automobile transportation, machinery manufacturing, material processing, electronic appliances, national defense and military industry, construction and building materials, petrochemical industry, printing and binding, light industry and textile, medical and health, and daily life.
[0005] Different types of adhesives are reported in literature for various applications in the manufacturing of batteries. Although huge number of different adhesives are reported but problems such as high manufacturing cost, poor acid resistance, insufficient toughness of the adhesive layer, poor bonding performance, poor temperature resistance, acid leakage, tank cover falling off, and non-availability of low-cost commercial raw materials still exist.
[0006] Despite the problems as described above, the prior art has failed to address and solve the problem of providing an effective, safe, cost effective and efficient sealant for batteries, which is having a long-time durability, and high level of safety.
[0007] Patent US2994455 discloses adhesives for sealing metallic-container seams composed of reaction products of amino imidazolines and epoxy resins.
[0008] Patent US2996693 discloses sealing compositions for electrical apparatus, wherein the material is the polymerization product of a polyfunctional, unsaturated acid anhydride, an epoxy resin monomer, and acrylonitrile.
[0009] Patent GB998361 discloses sealing composition consists of liquid bisphenol-epichlorohydrin epoxy resin, transphalt, aminoethylpiperazine, and coke. The epoxy resin is cured with an amine or fatty acid salt, the polyester with an organic peroxide.
[00010] Patent SU175183 discloses sealing material based on epoxy resins consists of epoxy resins, mineral filler (corundum, quartz glass, porcelain flour), fibrous filler (water-repellent glass fiber), and hardener (polyethylene polyamines, hydroxyalkyl polyamines).
[00011] Patent SU215366 discloses composition for coatings, sealants, and insulating materials, based on a bisphenol-A epoxy resin from epichlorohydrin and a mixture of alkylresorcinols (containing 5-methyl resorcinol), a hardener, plasticizer, and filler.
[00012] Patent GB1139115 discloses cured epoxy resin compositions prepared by mixing an epoxy-novolak resin and a liquid glycidyl polyether of a polyhydric phenol with Mg-silicate and a curing composition comprising various polyamides and an amine.
[00013] Patent JP53089943 discloses sealing of alkaline batteries adhesive layer based on a polyamide resin, an epoxy resin, and an amino-substituted silane (?-aminopropyltriethoxysilane or ?-aminopropyltrimethoxysilane).
[00014] Patent CN1445326 discloses nanomaterial-reinforced sealant for alkaline batteries, composed of nano-material (Carbon black or SiO2), epoxy resin, chlorosulfonylated polyethylene, triethylamine catalyst, solvent and other additives.
[00015] Patent CN102796350 discloses sealing material of lead-acid battery, composed of ABS (acrylonitrile-butadiene-styrene terpolymer), bisphenol F epoxy resin, trichloromethane, o-cresol glycidyl ether, polyurethane, silica filler, organic acid accelerator, coupling agent (silane or carbonate coupling agent), flame retardant and antioxidant (benzoic acid).
[00016] CN102850492 discloses battery sealant obtained by mixing nano grade silica, epoxy resin, chlorosulfonated polyethylene, tetraacetic acid, solvent, dithiol and styrene. CN102925093 discloses adhesive for sealing composed of bisphenol-A epoxy resin, nitrile rubber, polyester resin, silane coupling agent, reactive diluent, defoamers, levelling agent, pigment, filler, and dispersant.
[00017] CN103694643 discloses method for manufacturing battery sealing material using ABS (acrylonitrile-butadiene-styrene terpolymer), bisphenol-F epoxy resin, chloroform, o-cresol glycidyl ether, polyurethane, silica filler, accelerator, coupling agent, flame retardant and antioxidant.
[00018] CN103881444 discloses alkaline battery sealant coating prepared from nano silica, epoxy resin, chlorosulfonated polyethylene, tetra-acetic acid, solvent, dithiol, and styrene through mixing.
[00019] CN105969219 discloses sealant consists of component A and component B; wherein the component A is composed of N- ß-hydroxyethyl ethylenediamine, polyvinyl chloride, benzoyl peroxide, and chlorosulfonated polyethylene and the component B is composed of epoxy resin, Butyl acrylate, chloroprene rubber, nickel acetylacetonate, dioctyl phthalate, defoamer, and paraffin.
[00020] CN112694866 discloses liquid leakage-proof sealant for lithium battery cap and preparation method thereof. Sais sealant comprises silicon boron rubber, epoxy resin, nano zinc oxide, nano calcium carbonate, silicon carbide nanowire, curing accelerator and the balance of organic solvent.
[00021] CN115216262 discloses sealing filling material comprises component A and component B, wherein component A comprises resin matrix, inorganic thermally conductive filler and nanoscale metal powder and the component B comprises resin curing agent.
[00022] However, there is still a need in the art for new and improved adhesive composition suitable for industrial applications, in particular for battery sealing applications, where quick curing, excellent adhesion, high stability, low viscosity, long-lasting performance and high-level safety are required. The present disclosure satisfies these needs and provides further related advantages.
OBJECTS
[00023] It is an object of the present disclosure to provide a new and improved liquid epoxy adhesive composition suitable for industrial applications, in particular for battery sealing applications.
[00024] It is another object of the present disclosure to provide a liquid epoxy adhesive composition suitable for sealing terminals and lid of batteries.
[00025] It is another object of the present disclosure to provide a liquid epoxy adhesive composition that has low viscosity and exhibits excellent storage stability.
[00026] It is another object of the present disclosure to provide a liquid epoxy adhesive composition which has fast curing property.
[00027] It is another object of the present disclosure to provide a liquid epoxy adhesive composition which provides flame-resistant sealing and adhesion.
[00028] It is another object of the present disclosure to provide a liquid epoxy adhesive composition that has excellent chemical and impact resistance properties.
[00029] It is another object of the present disclosure to provide a liquid epoxy adhesive composition that has long durability and ensures high-level safety.
[00030] It is another object of the present disclosure to provide a convenient and inexpensive process for producing a liquid epoxy adhesive composition.

SUMMARY
[00031] Aspects of the present disclosure relate to a liquid epoxy adhesive composition suitable for industrial applications, in particular for battery sealing applications, where some or all of quick curing, excellent adhesion, high stability, low viscosity, long-lasting performance and high-level safety are required. According to the embodiments of the present disclosure, the liquid epoxy adhesive composition comprises a resin component (A) and a curing agent component (B). The resin component (A) comprises, based on the total weight of the component (A), 50-95% by weight of a binder and 1-25% by weight of a reactive diluent. The curing agent component (B) comprises, based on the total weight of the component (B), 25-80% by weight of an anime based curing agent, 1-25% by weight of a reactive diluent, 10-50% by weight of a non-reactive diluent, and 5-25% by weight of an accelerator.
[00032] In various embodiments, the resin component (A) can further include one or more of the following:
0.01-1% by weight of a defoaming agent;
0-20% by weight of a flame retardant;
0-25% by weight of a filler; and
0-2.5% by weight of a pigment.
[00033] In various embodiments, the curing agent component (B) can further include one or more of the following:
0.01-1% by weight of a defoaming agent;
0.01-0.5% by weight of a colour stabilizer; and
0-20% by weight of a flame retardant.
[00034] In various embodiments, the resin component (A) and the curing agent component (B) are present in the liquid epoxy adhesive composition in a volume ratio of from 2:1 to 5:2. Preferably, the resin component (A) and the curing agent component (B) are present in a volume ratio of 2:1.
[00035] In various embodiments, the liquid epoxy adhesive composition as described herein can be used for sealing terminals and lid of batteries, such as lithium-ion battery, lithium battery, and the like.
[00036] In another aspect, the present disclosure is directed to a process for preparing a liquid epoxy adhesive composition as described herein. The process includes the steps of:
i) mixing a binder and a reactive diluent to form a first mixture;
ii) heating the first mixture to a temperature of 50-80°C;
iii) cooling the first mixture to room temperature;
iv) mixing with the first mixture a defoamer and optionally a flame retardant, a pigment, a filler or a combination thereof to form a resin component (A);
v) mixing a non-reactive diluent, a reactive diluent, and an amine based curing agent to form a second mixture;
vi) heating the second mixture to a temperature of 70-85°C;
vii) cooling the second mixture to a temperature of 60-70°C;
viii) adding an accelerator and a reactive diluent to the second mixture;
ix) cooling the second mixture to a temperature of 40-50°C;
x) mixing with the second mixture a defoamer and optionally a flame retardant, a colour stabilizer or a combination thereof to form a curing agent component (B); and
xi) mixing the resin component (A) with the curing agent component (B) in a volume ratio of from 2:1 to 5:2 to form the liquid epoxy adhesive composition.
[00037] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

DETAILED DESCRIPTION
[00038] The following is a detailed description of embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[00039] The present disclosure provides a liquid epoxy adhesive composition suitable for industrial applications, in particular for battery sealing applications, where some or all of quick curing, excellent adhesion, high stability, low viscosity, long-lasting performance and high-level safety are required. The liquid epoxy adhesive composition as described herein is particularly suitable for use as a sealant for sealing terminals and lid of batteries, such as lithium-ion battery, lithium battery, and the like.
[00040] According to embodiments of the present disclosure, the liquid epoxy adhesive composition comprises a resin component (A) and a curing agent component (B). The resin component (A) comprises, based on the total weight of the component (A), 50-95% by weight of a binder and 1-25% by weight of a reactive diluent. The curing agent component (B) comprises, based on the total weight of the component (B), 25-80% by weight of an anime based curing agent, 1-25% by weight of a reactive diluent, 10-50% by weight of a non-reactive diluent, and 5-25% by weight of an accelerator.
[00041] In various embodiments, the resin component (A) can further include one or more of the following:
0.01-1% by weight of a defoaming agent;
0-20% by weight of a flame retardant;
0-25% by weight of a filler; and
0-2.5% by weight of a pigment.
[00042] In various embodiments, the curing agent component (B) can further include one or more of the following:
0.01-1% by weight of a defoaming agent;
0.01-0.5% by weight of a colour stabilizer; and
0-20% by weight of a flame retardant.
[00043] In various embodiments, the resin component (A) and the curing agent component (B) are present in the liquid epoxy adhesive composition in a volume ratio of from 2:1 to 5:2. Preferably, the resin component (A) and the curing agent component (B) are present in a volume ratio of 2:1.
[00044] In certain embodiments, the liquid epoxy adhesive composition of the present disclosure comprises the following components:
Resin component (A)
S. N. Ingredient Weight % Range
1. Binder 50-95%
2. Reactive diluent 1-25%
3. Flame retardant 0-20%
4. Defoaming agent 0.01-1%
5. Filler 0-25%
6. Pigment 0-2.5%
Curing agent component (B)
S. N. Ingredient Weight % Range
1. Amine based curing agent 25-80%
2. Reactive diluent 1-25%
3. Non-reactive diluent 10-50%
4. Accelerator 5-25%
5. Flame retardant 0-20%
6. Defoaming agent 0.01-1%
7. Colour stabilizer 0.01-0.5%

[00045] The binder used in the resin component (A) is an epoxy resin, based on Bisphenol A or Bisphenol F. Non-limiting examples of binder include bisphenol A-epichlorohydrin epoxy resin, bisphenol F-epichlorohydrin epoxy resin, diglycidyl ether of novolac resin, hydrogenated bisphenol A, F or A/F epoxy resin, bisphenol-A diglycidyl ether, and combinations thereof.
[00046] In an embodiment, the epoxy resin may be a single resin. In another embodiment, the epoxy resin is a mixture of mutually compatible epoxy resins.
[00047] The reactive diluent includes, but not limited to, glycidyl ethers of phenols, cresols, alkyl phenols, aromatic amine, butanol, C10 to C14 alcohols and mixture thereof. Examples of reactive diluents include phenylglycidyl ether, butylglycidyl ether, poly(propylene glycol) diglycidyl ether, allylglycidyl ether, butanediol diglycidyl ether, aniline, and mixtures thereof. Preferable reactive diluents include phenylglycidyl ether, aniline, poly(propylene glycol) diglycidyl ether, and mixture thereof. The reactive diluent may also work as flexibilizer or viscosity minimizer.
[00048] The flame retardant includes, but not limited to, tricresyl phosphate, triethyl phosphate, triphenyl phosphate, trixylenyl phosphate, organophosphorous compounds with different functionalities, halogenated phosphoric acid esters, and polyesters, phosphonates and phosphinate, non-halogenated phosphoric acid esters, boron compounds, brominated epoxy resins, brominated bisphenol, brominated diphenyl ethers, aluminium trihydroxide, melamine, chlorinated paraffins, borates, stannates, and mixtures thereof. In some embodiments, tricresyl phosphate is used as flame retardant.
[00049] The filler includes, but not limited to, barium sulfate, silica, alumina, silicates, hydrated magnesium silicate (or talc), hydrated potassium aluminum silicate, kaolin, glass flakes, calcium sulfate, micaceous iron oxide, aluminum trihydrate, aluminum oxide, aluminum nitride, quartz, boron nitride, silicon carbide, and mixtures thereof. Based on the filler loading, formulation system can provide superior thermal conductivity, dimensional stability and abrasion resistance.
[00050] The defoaming agent includes, but not limited to, organo-modified polysiloxane, modified silicone, mineral oil, fluorocarbon or vinyl and acrylic based suitable defoamer, a silicone defoaming agent, a polyether defoaming agent, a polyether modified silicone defoaming agent, and mixtures thereof. Non-limiting examples of defoamer include hydroxy group-containing dimethyl siloxanes, commercially available products such as Tego Airex® 900, 990, BYK 1760, BYK-A530, Efka® PB 2744 etc. In some embodiments, BYK-A530 is used as the defoaming agent.
[00051] The amine based curing agent includes, but not limited to, polyamidoamine, mercaptan modified polyamines, cycloaliphatic amines, phenalkamine or cashew nutshell oil polymer with formaldehyde, ethylene diamine, diethylenetriamine, triethylenetetramine, meta-xylenediamine and aromatic polyamine such as 4,4'-diaminodiphenyl methane, and mixtures thereof. In some embodiments, the amine based curing agent is 4,4'-diaminodiphenyl methane.
[00052] The non-reactive diluent includes, but not limited to, benzyl alcohol, cardanol, xylene, toluene, and mixtures thereof. Non-reactive diluent may also work as flexibilizer cum toughening agent or viscosity minimizer. In some embodiments, the non-reactive diluent is benzyl alcohol, cardanol, or a mixture thereof. In some embodiments, the non-reactive diluent is a mixture of benzyl alcohol and cardanol. Cardanol provides hydrophobicity and therefore enhances water resistance of sealing/cured composition. Cardanol also increases flexibility and impact resistance due to the presence of long aliphatic chain in the backbone of the molecule.
[00053] The accelerator includes, but not limited to 2,4,6-tris(dimethylaminomethyl)phenol, phenol, meta cresol, para cresol, salicylic acid, bisphenol-A, bisphenol-F, resorcinol, catechol, triethanolamine, N,N-dimethyldipropylenetriamine, and mixtures thereof. In some embodiments, salicylic acid is used as the accelerator.
[00054] The colour stabilizer includes, but not limited to, phenyl hydrazine, hydrazine hydrate, hydroxylamine and its derivatives, sodium borohydrate, and mixtures thereof. In some embodiments, the colour stabilizer is phenyl hydrazine.
[00055] The pigment can be an organic pigment or an inorganic pigment. Non-limiting examples of pigment include carbon black, white lead, graphite, zinc sulfide, chromium oxide, yellow nickel titanium, yellow chromium titanium, violet-19, yellow iron oxide, red iron oxide, black iron oxide, phthalocyanine blue, phthalocyanine green, ultramarine blue, direct blue, Prussian blue, benzimidazolone yellow, quinacridone red, azo red/yellow pigments, aniline yellow, janus green, and mixtures thereof.
[00056] In various embodiments, the liquid epoxy adhesive composition as described herein can be applied on substrates to be bonded in a conventional manner using techniques familiar to a person skilled in the art. Suitable techniques of application include, but not limited to, manual potting and automated dispensing.
[00057] In various embodiments, the liquid epoxy adhesive composition as described herein can provide excellent adhesion to a variety of substrates, including acrylonitrile butadiene styrene (ABS), styrene acrylonitrile (SAN), rubber, metal, polypropylene, polycarbonate, hard rubber, and various plastics.
[00058] In various embodiments, the liquid epoxy adhesive composition as described herein can provide excellent adhesion between two different substrates, for example, ABS to metal adhesion, rubber to ABS adhesion, SAN to metal adhesion, and rubber to metal adhesion.
[00059] In an embodiment, the liquid epoxy adhesive composition has a pot-life of 8-13 minutes at room temperature and has a full cure time of 30 minutes at a temperature of 25°C to 35°C.
[00060] The components (A) and (B) of the composition are storage-stable, meaning that they can be stored prior to use for several months up to one year or longer without any change in their respective properties to a degree relevant to their use.
[00061] For application of the liquid epoxy composition, the components (A) and (B) can be mixed with one another shortly before or during application. In various embodiments, the components (A) and (B) can be produced separately from one another and stored in separate air-tight containers until they are mixed with one another for application shortly before or during application, and the adhesive composition ultimately cures. When the components (A) and (B) are mixed, the process of curing starts. This results in a cured composition. In various embodiments, the adhesive composition cures at room temperature and forms a cured composition having a non-tacky surface, excellent adhesion strength, and excellent mechanical, electrical, thermal and chemical resistance properties.
[00062] The components (A) and (B) can be mixed with one another by any suitable method, and this mixing may be done continuously or batch wise. Mixing can be carried out at a temperature ranging from 5°C to 50°C., preferably from 10°C to 30°C. In various embodiments, the resin component (A) and the curing agent component (B) can be mixed in a volume ratio of from 2:1 to 5:2. The mixing ratio is preferably 2:1.
[00063] In another aspect, the present disclosure is directed to a process for preparing the liquid epoxy adhesive composition as described herein. The process includes the steps of:
i) mixing a binder and a reactive diluent to form a first mixture;
ii) heating the first mixture to a temperature of 50-80°C;
iii) cooling the first mixture to room temperature;
iv) mixing with the first mixture a defoamer and optionally a flame retardant, a pigment, a filler or a combination thereof to form a resin component (A);
v) mixing a non-reactive diluent, a reactive diluent, and an amine based curing agent to form a second mixture;
vi) heating the second mixture to a temperature of 70-85°C;
vii) cooling the second mixture to a temperature of 60-70°C;
viii) adding an accelerator and a reactive diluent to the second mixture;
ix) cooling the second mixture to a temperature of 40-50°C;
x) mixing with the second mixture a defoamer and optionally a flame retardant, a colour stabilizer or a combination thereof to form a curing agent component (B); and
xi) mixing the resin component (A) with the curing agent component (B) in a volume ratio of from 2:1 to 5:2 to form the liquid epoxy adhesive composition.
EXAMPLES
[00064] The invention is now being illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. The invention will now be explained in more detail that illustrates the invention in a non-limiting matter.
Example 1
1) Preparation of resin component (A): In a clean round bottom flask, add 80% by weight of bisphenol-A diglycidyl ether, 9.92% by weight of polypropylene glycol diglycidyl ether at room temperature and heat the mixture to 50-60°C. Stir well for one hour. Add 10% by weight of tricresyl phosphate and stir well for another one hour. Cool to room temperature and add 0.08% by weight BYK-A530. Stir well to uniform mixing and pack in drum after filtration.
2) Preparation of curing agent component (B): In a clean round bottom flask, add 9.65% by weight of benzyl alcohol and 19% by weight of cardanol at room temperature. Add 46% by weight 4,4-diaminodiphenyl methane under stirring and heat the mixture to 70-85°C. Once material is completely dissolved, apply vacuum for one hour (700-720 mmHg). Release vacuum and add 12% by weight salicylic acid at 60-70°C and allow to dissolve it for 30 min. Add 5% by weight phenyl glycidyl ether within one hour at 65-75°C, and maintain it for further one hour. Cool reaction mass to 50°C, and charge 8% by weight of tricresyl phosphate. Charge 0.15% by weight of BYK-A530, and 0.2% by weight of phenyl hydrazine. Stir well to uniform mixing and pack in drum after filtration.
3) The component (A) and the component (B) were mixed by mechanical stirrer in a ratio of 2:1 by volume to form a liquid epoxy adhesive composition. Components (A) and (B) were thoroughly mixed with one another prior to application on substrates.
Example 2
[00065] Resin component (A) and curing agent component (B) were prepared according to the ingredients and amounts shown in Tables 2a and 2b, respectively. The component (A), the component (B) and the adhesive composition were prepared using a process similar to the one in Example 1.
Table 2a: Resin component (A)
S. N. Ingredient Weight %
1. Bisphenol-A diglycidyl ether 64.91%
2. Polypropylene glycol diglycidyl ether 8%
3. Tricresyl phosphate 10%
4. BYK-A530 0.09%
5. Silica 16%
6. Phthalocyanine blue 1%

Table 2b: Curing agent component (B)
S. N. Ingredient Weight %
1. Benzyl alcohol 8.85%
2. Cardanol 20%
3. 4,4-Diaminodiphenyl methane 44%
4. Salicylic acid 12%
5. Phenyl glycidyl ether 7%
6. Tricresyl phosphate 8%
7. BYK-A530 0.15%

Example 3
[00066] Resin component (A) and curing agent component (B) were prepared according to the ingredients and amounts shown in Tables 3a and 3b, respectively. The component (A), the component (B) and the adhesive composition were prepared using a process similar to the one in Example 1.

Table 3a: Resin component (A)
S. N. Ingredient Weight %
1. Bisphenol-A diglycidyl ether 65%
2. Polypropylene glycol diglycidyl ether 7.9%
3. Tricresyl phosphate 11%
4. BYK-A530 0.10%
5. Aluminum trihydrate 15%
6. Pigment Violet 19 1%

Table 3b: Curing agent component (B)
S. N. Ingredient Weight %
1. Benzyl alcohol 9.85%
2. Cardanol 17%
3. 4,4-Diaminodiphenyl methane 46%
4. Salicylic acid 14%
5. Phenyl glycidyl ether 5%
6. Tricresyl phosphate 8%
7. BYK-A530 0.15%

Example 4
1) Preparation of resin component (A): In a clean round bottom flask, add 91% by weight of bisphenol-A diglycidyl ether, 8.95% by weight of n-butyl glycidyl ether at room temperature and heat the mixture to 75-80°C. Stir well for one hour. Slowly apply vacuum (700-720 mmHg) to remove traces of volatiles in the resin. Cool to 40°C and add 0.05% by weight BYK-A530. Stir well to uniform mixing and pack in drum after filtration.
2) Preparation of curing agent component (B): In a clean round bottom flask, add 18.65% by weight of benzyl alcohol, 6% by weight of aniline, 54% by weight of 4,4-diaminodiphenyl methane under stirring and heat the mixture to 70-85°C. Once material is completely dissolved, apply vacuum for one hour (700-720 mmHg). Release vacuum with nitrogen purging and cool reaction mass to 65-70°C. Add 12% by weight salicylic acid at 60-70°C and allow to dissolve it for 30 min. Add 10% by weight phenyl glycidyl ether slowly in 1-2hr at 65°C, and maintain it for further one hour. Cool reaction mass to 40-50°C, and charge 0.15% by weight of BYK-A530, and 0.2% by weight of phenyl hydrazine. Stir well to uniform mixing and pack in drum after filtration.
3) The component (A) and the component (B) were uniformly mixed by mechanical stirrer in a ratio of 2:1 by volume to form the liquid epoxy adhesive composition. Components (A) and (B) were thoroughly mixed with one another prior to application.
Example 5
[00067] Resin component (A) and curing agent component (B) were prepared according to the ingredients and amounts shown in Tables 5a and 5b, respectively. A process similar to the one in Example 4 was used to prepare the component (A), the component (B) and the adhesive composition.

Table 5a: Resin component (A)
S. N. Ingredient Weight %
1. Bisphenol-A diglycidyl ether 70%
2. n-Butyl glycidyl ether 12.95%
3. BYK-A530 0.05%
4. Silica 16%
5. Phthalocyanine green 1%

Table 5b: Curing agent component (B)
S. N. Ingredient Weight %
1. Benzyl alcohol 12.65%
2. Aniline 6%
3. 4,4-Diaminodiphenyl methane 59%
4. Salicylic acid 12%
5. Phenyl glycidyl ether 10%
6. Phenyl hydrazine 0.2%
7. BYK-A530 0.15%

Example 6
[00068] Resin component (A) and curing agent component (B) were prepared according to the ingredients and amounts shown in Tables 6a and 6b, respectively. A process similar to the one in Example 4 was used to prepare the component (A), the component (B) and the adhesive composition.

Table 6a: Resin component (A)
S. N. Ingredient Weight %
1. Bisphenol-A diglycidyl ether 73%
2. n-Butyl glycidyl ether 10.95%
3. BYK-A530 0.05%
4. Aluminum trihydrate 15%
5. Carbon black 1%

Table 6b: Curing agent component (B)
S. N. Ingredient Weight %
1. Benzyl alcohol 13.65%
2. Aniline 6%
3. 4,4-Diaminodiphenyl methane 52%
4. Salicylic acid 14%
5. Phenyl glycidyl ether 14%
6. Phenyl hydrazine 0.2%
7. BYK-A530 0.15%

[00069] The present disclosure may, of course, be carried out in other specific ways than those herein set forth without parting from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00070] The present disclosure provides a liquid epoxy adhesive composition which is suitable for sealing terminals and lid of batteries.
[00071] The present disclosure provides a liquid epoxy adhesive composition having, before curing, a low viscosity adapted for easy application on the substrates to be bonded.
[00072] The present disclosure provides a liquid epoxy adhesive composition that exhibits excellent storage stability.
[00073] The present disclosure provides a liquid epoxy adhesive composition which has fast curing property.
[00074] The present disclosure provides a liquid epoxy adhesive composition which provides flame-resistant sealing and adhesion.
[00075] The present disclosure provides a liquid epoxy adhesive composition that has excellent chemical, heat and impact resistance properties.
[00076] The present disclosure provides a liquid epoxy adhesive composition that has long durability and ensures high-level safety.
[00077] The present disclosure provides a convenient and inexpensive process for producing a liquid epoxy adhesive composition.
, Claims:1. An epoxy adhesive composition, comprising: a resin component (A) and a curing agent component (B), wherein
the resin component (A) comprises, based on the total weight of the resin component (A),
50-95% by weight of a binder; and
1-25% by weight of a reactive diluent;
the curing agent component (B) comprises, based on the total weight of the curing agent component (B),
25-80% by weight of an anime based curing agent;
1-25% by weight of a reactive diluent;
10-50% by weight of a non-reactive diluent; and
5-25% by weight of an accelerator.
2. The composition as claimed in claim 1, wherein the resin component (A) and the curing agent component (B) are present in a volume ratio of from 2:1 to 5:2.
3. The composition as claimed in claim 1, wherein the resin component (A) further comprises one or more of the following:
0.01-1% by weight of a defoaming agent;
0-20% by weight of a flame retardant;
0-25% by weight of a filler; and
0-2.5% by weight of a pigment.
4. The composition as claimed in claim 1, wherein the curing agent component (B) further comprises one or more of the following:
0.01-1% by weight of a defoaming agent;
0.01-0.5% by weight of a colour stabilizer; and
0-20% by weight of a flame retardant.
5. The composition as claimed in claim 1, wherein
the binder is selected from the group consisting of bisphenol A-epichlorohydrin epoxy resin, bisphenol F-epichlorohydrin epoxy resin, diglycidyl ether of novolac resin, hydrogenated bisphenol A, F or A/F epoxy resin, bisphenol-A diglycidyl ether, and combinations thereof;
the amine based curing agent is selected from the group consisting of polyamidoamine, mercaptan modified polyamines, cycloaliphatic amines, phenalkamine or cashew nutshell oil polymer with formaldehyde, ethylene diamine, diethylenetriamine, triethylenetetramine, meta-xylenediamine, aromatic polyamine and a mixture thereof; preferably 4,4'-diaminodiphenyl methane;
the reactive diluent is selected from the group consisting of glycidyl ethers of phenols, cresols, alkyl phenols, aromatic amine, butanol and C10 to C14 alcohols; preferably from the group consisting of phenylglycidyl ether, butylglycidyl ether, poly(propylene glycol) diglycidyl ether, allylglycidyl ether, butanediol diglycidyl ether, aniline, and a mixture thereof;
the non-reactive diluent is selected from the group consisting of benzyl alcohol, cardanol, xylene, toluene, and mixtures thereof; and
the accelerator is selected from the group consisting of 2,4,6-tris(dimethylaminomethyl)phenol, phenol, meta cresol, para cresol, salicylic acid, bisphenol-A, bisphenol-F, resorcinol, catechol, triethanolamine, N,N-dimethyldipropylenetriamine, and mixtures thereof.
6. The composition as claimed in claims 3 and 4, wherein
the defoaming agent is selected from the group consisting of organo-modified polysiloxane, modified silicone, mineral oil, fluorocarbon or vinyl and acrylic based defoamer, a silicone defoaming agent, a polyether defoaming agent, a polyether modified silicone defoaming agent, and mixtures thereof; preferably from the group consisting of hydroxy group-containing dimethyl siloxanes, Tego Airex® 900, Tego Airex® 990, BYK-1760, BYK-A530, and Efka® PB 2744;
the colour stabilizer is selected from the group consisting of phenyl hydrazine, hydrazine hydrate, hydroxylamine and its derivatives, sodium borohydrate, and mixtures thereof;
the flame retardant is selected from the group consisting of tricresyl phosphate, triethyl phosphate, triphenyl phosphate, trixylenyl phosphate, organophosphorous compounds with different functionalities, halogenated phosphoric acid esters, and polyesters, phosphonates and phosphinate, non-halogenated phosphoric acid esters, boron compounds, brominated epoxy resins, brominated bisphenol, brominated diphenyl ethers, aluminium trihydroxide, melamine, chlorinated paraffins, borates and stannates, and mixtures thereof;
the filler is selected from the group consisting of barium sulfate, silica, alumina, silicates, hydrated magnesium silicate (or talc), aluminum trihydrate, hydrated potassium aluminum silicate, kaolin, glass flakes, calcium sulfate, micaceous iron oxide, aluminum oxide, aluminum nitride, quartz, boron nitride, silicon carbide, and mixtures thereof; and
the pigment is selected from the group consisting of carbon black, white lead, graphite, zinc sulfide, chromium oxide, yellow nickel titanium, yellow chromium titanium, violet-19, yellow iron oxide, red iron oxide, black iron oxide, phthalocyanine blue, phthalocyanine green, ultramarine blue, direct blue, Prussian blue, benzimidazolone yellow, quinacridone red, azo red/yellow pigments, aniline yellow, janus green, and mixture thereof.
7. A process for preparation of an epoxy adhesive composition as claimed in any of the preceding claims, comprising the steps of:
i) mixing a binder and a reactive diluent to form a first mixture;
ii) heating the first mixture to a temperature of 50-80°C;
iii) cooling the first mixture to room temperature;
iv) mixing with the first mixture a defoamer and optionally a flame retardant, a pigment, a filler or a combination thereof to form a resin component (A);
v) mixing a non-reactive diluent, a reactive diluent, and an amine based curing agent to form a second mixture;
vi) heating the second mixture to a temperature of 70-85°C;
vii) cooling the second mixture to a temperature of 60-70°C;
viii) adding an accelerator and a reactive diluent to the second mixture;
ix) cooling the second mixture to a temperature of 40-50°C;
x) mixing with the second mixture a defoamer and optionally a flame retardant, a colour stabilizer or a combination thereof to form a curing agent component (B); and
xi) mixing the resin component (A) with the curing agent component (B) in a volume ratio of from 2:1 to 5:2 to form the liquid epoxy adhesive composition.