Curable resin composition and adhesive composition

Abstract

The present invention relates to a curable resin composition, which uses an environmentally friendly bio-based epoxy resin instead of an existing petroleum-based epoxy resin, thereby reducing environmental pollution and satisfying all of the mechanical strength properties required of curable resin compositions containing existing petroleum-based epoxy resins. The present invention also relates to a curable resin composition and an adhesive composition containing the same, which have excellent productivity and mechanical properties, as a graft copolymer is dispersed in the curable resin by a powder dispersion method.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0018787, filed February 13, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a curable resin composition and an adhesive composition containing the same as a toughening agent. [Background technology]

[0003] Curable resins, such as epoxy resins, are used in a variety of fields, including electrical and electronic products, automotive parts, and building materials. With the recent growing interest in environmentally friendly biomaterials, efforts are being made to apply environmentally friendly biomaterials to epoxy resins. The use of environmentally friendly bio-based epoxy resins instead of existing petroleum-based epoxy resins can reduce environmental pollution that occurs during the production of petroleum-based raw materials.

[0004] On the other hand, curable resins such as epoxy resins are often used in combination with additives such as inorganic fillers, mold release agents, and rubber particles with rubber-type properties to enhance physical properties and processability, rather than being used alone. Epoxy resins, in particular, often exhibit brittle properties, and therefore require improvements in impact resistance and adhesive strength. This applies not only to existing petroleum-based epoxy resins, but also to environmentally friendly bio-based epoxy resins.

[0005] A method for improving the impact resistance of epoxy resins has been proposed in which a graft copolymer containing a rubbery polymer is used as an impact modifier. The graft copolymer has a core-shell particle morphology, with a core containing a rubbery polymer and a shell formed by graft polymerization onto the core.

[0006] In order to use the graft copolymer as an impact modifier for epoxy resin, the graft copolymer needs to be dispersed in the epoxy resin. Methods for dispersing the graft copolymer in the epoxy resin include a liquid dispersion method and a powder dispersion method.

[0007] The liquid dispersion method involves dispersing the graft copolymer in an epoxy resin by a stepwise solvent substitution method, in which the water is substituted with a solvent for the graft copolymer in a latex state in which the graft copolymer is dispersed in water, and then the solvent is substituted again with an epoxy resin. This liquid dispersion method has the advantage of dispersing the graft copolymer in a homogeneous distribution matrix of the epoxy resin, but it has storage problems because the graft copolymer must be stored in a latex state until it is dispersed in the epoxy resin in order to be used as an impact modifier. The solvent substitution process is costly, and there are environmental problems due to the graft copolymer and the water and solvent that are separated and discharged during the solvent substitution process.

[0008] The powder dispersion method has the advantage of low process costs because the dry powder agglomerated from the graft copolymer latex, i.e., the powdery graft copolymer, is directly dispersed in the epoxy resin. However, when the graft copolymer powder is directly introduced into the epoxy resin, the viscosity of the graft copolymer powder becomes very high, making dispersion very difficult or impossible.

[0009] Therefore, efforts are being made to use environmentally friendly bio-based epoxy resins instead of existing petroleum-based epoxy resins and to satisfy all of the mechanical strength properties required of curable resin compositions containing existing petroleum-based epoxy resins, and simultaneously to apply a powder dispersion method to improve both process costs and environmental aspects when applying impact modifiers to curable resin compositions such as epoxy resins. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP2006-104328 A Summary of the Invention [Problem to be solved by the invention]

[0011] The problem to be solved by the present invention is to reduce environmental pollution by applying an environmentally friendly bio-based epoxy resin instead of an existing petroleum-based epoxy resin, while satisfying all of the mechanical strength properties required of a curable resin composition containing an existing petroleum-based epoxy resin.

[0012] Another problem to be solved by the present invention is to apply a powder dispersion method to improve both process costs and environmental aspects when applying an impact modifier to a curable resin composition containing an environmentally friendly bio-based epoxy resin.

[0013] That is, in order to solve the problems mentioned in the Background of the Invention, the present invention aims to provide a curable resin composition that uses an environmentally friendly bio-based epoxy resin instead of an existing petroleum-based epoxy resin, that satisfies all of the mechanical strength properties required of a curable resin composition containing an existing petroleum-based epoxy resin, and that has excellent productivity and mechanical properties, in which a graft copolymer is dispersed in the curable resin by a powder dispersion method.

[0014] Another object of the present invention is to provide a structural adhesive composition that contains an environmentally friendly bio-based epoxy resin as a base resin and has excellent mechanical strength by applying the curable resin composition as a toughening agent. [Means for solving the problem]

[0015] In order to solve the above problems, the present invention provides a curable resin composition and an adhesive composition.

[0016] (1) The present invention provides a curable resin composition comprising a continuous phase containing a curable resin and a dispersed phase containing a graft copolymer, wherein the curable resin comprises a bio-curable resin and an epoxy resin; the curable resin is obtained by dissolving 0.2 g of a sample of the curable resin composition in acetone, adding 40 mL of methanol, and then filtering the supernatant using a 0.22 μm polytetrafluoroethylene filter into a 2 mL liquid chromatography vial; and using high performance liquid chromatography (HPLC), the peak area ratio of the bio-curable resin to the epoxy resin, as detected by an evaporative light scattering detector (ELSD) based on elution time (bio-curable resin:epoxy resin), is 0.60 to 5.60:1.

[0017] (2) The present invention provides the curable resin composition according to (1), wherein the bio-curable resin is a bio-epoxy resin.

[0018] (3) The present invention provides the curable resin composition according to (1) or (2), wherein the bio-curable resin contains an isosorbide unit.

[0019] (4) The present invention provides a curable resin composition according to any one of the above (1) to (3), wherein the bio-curable resin is represented by the following chemical formula 1:

[0020] [ka]

[0021] In the above chemical formula 1, R 1 and R 2 are each independently hydrogen, a hydroxy group, an epoxy group, or a glycidyl group, and n is an integer selected from 1 to 1,000.

[0022] (5) The present invention provides a curable resin composition according to any one of (1) to (4), wherein the bio-curable resin has an epoxy equivalent weight (EEW) of 150 g / eq or more and 190 g / eq or less.

[0023] (6) The present invention provides a curable resin composition according to any one of (1) to (5) above, wherein the bio-curable resin has a viscosity at 25° C. of 500 cPs or more and 6,000 cPs or less.

[0024] (7) The present invention provides a curable resin composition according to any one of (1) to (6) above, wherein the epoxy resin comprises at least one selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AD ​​epoxy resins, bisphenol E epoxy resins, naphthalene epoxy resins, biphenyl epoxy resins, dicyclopentadiene epoxy resins, phenol novolac epoxy resins, alicyclic epoxy resins, and glycidylamine epoxy resins.

[0025] (8) The present invention provides the curable resin composition according to any one of (1) to (7), wherein the epoxy resin has an epoxy equivalent weight (EEW) of 180 g / eq or more and 190 g / eq or less.

[0026] (9) The present invention provides the curable resin composition according to any one of (1) to (8) above, wherein the epoxy resin has a viscosity at 25° C. of 8,000 cPs or more and 13,500 cPs or less.

[0027] (10) The present invention provides a curable resin composition according to any one of (1) to (9), wherein the curable resin contains 58% by weight or more and 82% by weight or less of a bio-curable resin and 18% by weight or more and 42% by weight or less of an epoxy resin.

[0028] (11) The present invention provides a curable resin composition according to any one of (1) to (10), wherein the graft copolymer has a core-shell structure, the core including a rubber polymer and a shell formed by graft polymerizing a graft monomer onto the rubber polymer.

[0029] (12) The present invention provides a curable resin composition according to (11), wherein the rubbery polymer contains one or more monomer units selected from the group consisting of conjugated diene-based monomer units and alkyl acrylate-based monomer units.

[0030] (13) The present invention provides the curable resin composition according to (11) or (12), wherein the graft monomer comprises an alkyl(meth)acrylate monomer.

[0031] (14) The present invention provides a curable resin composition according to any one of (11) to (13) above, wherein the graft monomer comprises a methyl (meth)acrylate monomer and an alkyl (meth)acrylate monomer having 2 to 12 carbon atoms.

[0032] (15) The present invention provides the curable resin composition according to any one of the above (11) to (14), wherein the graft monomer further contains an aromatic vinyl monomer.

[0033] (16) The present invention provides a curable resin composition according to any one of (11) to (15), wherein the graft copolymer contains 70% by weight or more and 92% by weight or less of a core and 8% by weight or more and 30% by weight or less of a shell.

[0034] (17) The present invention provides the curable resin composition according to any one of (11) to (16) above, wherein the core has an average particle size of 100 nm or more and 500 nm or less.

[0035] (18) The present invention provides the curable resin composition according to any one of (11) to (17), wherein the shell has a weight average molecular weight of 10,000 g / mol or more and 85,000 g / mol or less.

[0036] (19) The present invention provides the curable resin composition according to any one of the above (11) to (18), wherein the graft copolymer has an average particle size of 100 nm to 600 nm.

[0037] (20) The present invention provides an adhesive composition containing the curable resin composition according to any one of (1) to (19) above.

[0038] (21) The present invention provides the adhesive composition according to (20), wherein the adhesive composition comprises a base agent, a toughening agent, a urethane resin, and a curing agent, and the toughening agent is the curable resin composition.

[0039] (22) The present invention provides an adhesive composition according to the above (21), wherein the main agent contains a bio-curable resin.

[0040] (23) The present invention provides an adhesive composition according to (22) above, wherein the main agent contains a bio-curable resin in an amount of 1% by weight or more and 40% by weight or less relative to the total content of the adhesive composition.

[0041] (24) The present invention provides an adhesive composition according to any one of (21) to (23) above, wherein the adhesive composition contains a toughening agent in an amount of 5% by weight or more and 32% by weight or less, based on the total content of the adhesive composition. [Effects of the Invention]

[0042] The curable resin composition of the present invention uses an environmentally friendly bio-based epoxy resin instead of a conventional petroleum-based epoxy resin, thereby reducing environmental pollution and satisfying all of the mechanical strength properties required of conventional curable resin compositions containing petroleum-based epoxy resins. The graft copolymer is dispersed in the curable resin by a powder dispersion method, resulting in excellent productivity and excellent mechanical properties.

[0043] The adhesive composition of the present invention is a structural adhesive composition, and by using the curable resin composition as a toughening agent, the adhesive composition contains an environmentally friendly bio-based epoxy resin as a base resin and has excellent mechanical strength. DETAILED DESCRIPTION OF THE INVENTION

[0044] The present invention will now be described in more detail to aid in understanding the present invention.

[0045] The terms and words used in the description of the present invention and the claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their inventions.

[0046] In the present invention, the term "monomer unit" may refer to a component, structure, or substance itself derived from a monomer, and as a specific example, may refer to a repeating unit formed in a polymer when an input monomer participates in a polymerization reaction during polymerization of a polymer.

[0047] As used herein, the term "composition" includes mixtures of materials comprising the composition as well as reaction products and decomposition products formed from the materials of the composition.

[0048] The present invention provides a curable resin composition.

[0049] According to one embodiment of the present invention, the curable resin composition may include a bio-curable resin as the curable resin and a graft copolymer as an impact modifier. As a specific example, the graft copolymer may be dispersed in a powder form in the curable resin.

[0050] According to one embodiment of the present invention, the curable resin composition comprises a continuous phase containing a curable resin and a dispersed phase containing a graft copolymer, and the curable resin comprises a bio-curable resin and an epoxy resin. 0.2 g of a sample of the curable resin composition is dissolved in acetone, 40 mL of methanol is added, and the supernatant is filtered into a 2 mL liquid chromatography vial using a 0.22 μm polytetrafluoroethylene filter. Using high performance liquid chromatography (HPLC), the peak area ratio of the bio-curable resin to the epoxy resin (bio-curable resin:epoxy resin), detected by elution time with an evaporative light scattering detector (ELSD), may be 0.60 to 5.60:1.

[0051] According to one embodiment of the present invention, the bio-curable resin is an environmentally friendly bio-based curable resin, and may be a curable resin made from a bio-based material.

[0052] According to one embodiment of the present invention, the bio-curable resin may include units derived from one or more bio-based materials selected from the group consisting of plant-derived fatty acid oils, isosorbide, furan derivatives, tannin derivatives, terpene derivatives, rosin derivatives, lignin, and lignin derivatives. Specifically, the units derived from plant-derived fatty acid oils may be one or more selected from the group consisting of epoxidized soybean oil units, epoxidized castor oil units, epoxidized linseed oil units, epoxidized canola oil units, and epoxidized black jasmine seed oil units. Additionally, the units derived from furan derivatives may be one or more selected from the group consisting of 2,5-furandicarboxylic acid diglycidyl ester units and furfuryl glycidyl ether units.

[0053] According to one embodiment of the present invention, the biocurable resin may include an isosorbide unit. Isosorbide, which forms the isosorbide unit, is a derivative derived from sorbitol and is a bio-based material that can be produced at low cost. Specifically, the isosorbide can be obtained by dehydration of sorbitan. Sorbitan can be obtained by dehydration of sorbitol, and sorbitol can be obtained by hydrogenation of glucose. Glucose can be obtained by depolymerization of polysaccharides such as cellulose and starch.

[0054] According to one embodiment of the present invention, the bio-curable resin may be a bio-epoxy resin containing an isosorbide unit. Specifically, the bio-curable resin may be a copolymer containing an isosorbide unit and an epoxy unit, and more specifically, the bio-curable resin may be represented by the following Chemical Formula 1:

[0055] [ka]

[0056] In the above chemical formula 1, R 1 and R 2 are each independently hydrogen, a hydroxy group, an epoxy group, or a glycidyl group, and n can be an integer selected from 1 to 1,000. Specific examples of n include 1 or more, 5 or more, or 10 or more, and 1,000 or less, 900 or less, 800 or less, 700 or less, 600 or less, 500 or less, 400 or less, 300 or less, 200 or less, or 100 or less. The wavy bond lines may also be used to represent hydrogen, oxygen, R 1 and R 2It can be either a solid wedge or a dotted wedge. A specific example is a group consisting of two hydrogens, an oxygen atom, and an R 2 The wavy bond lines represented by R may have the same orientation, i.e., either a solid wedge or a dotted wedge, and R 1 The wavy bond represented by the symbol ≡ ... 2 It can exhibit the opposite stereo orientation.

[0057] According to one embodiment of the present invention, the bio-curable resin may have an epoxy equivalent weight (EEW) of 150 g / eq or more and 190 g / eq or less. Specific examples of the bio-curable resin include an epoxy equivalent weight of 150 g / eq or more, 155 g / eq or more, 160 g / eq or more, or 165 g / eq or more, and 190 g / eq or less, 185 g / eq or less, 180 g / eq or less, 175 g / eq or less, or 170 g / eq or less. Within this range, the bio-curable resin may exhibit the effect of a dissimilar adhesive, particularly a structural adhesive.

[0058] According to one embodiment of the present invention, the bio-curable resin may have a viscosity at 25° C. of 500 cPs or more and 6,000 cPs or less. Specific examples of the bio-curable resin may have a viscosity at 25° C. of 500 cPs or more, 1,000 cPs or more, 1,500 cPs or more, 2,000 cPs or more, 2,500 cPs or more, or 3,000 cPs or more, or 6,000 cPs or less, 5,500 cPs or less, 5,000 cPs or less, 4,500 cPs or less, 4,000 cPs or less, 3,500 cPs or less, 3,000 cPs or less, 2,500 cPs or less, or 2,000 cPs or less. Within these ranges, the viscosity is low during formulation of the structural adhesive composition, thereby improving workability.

[0059] According to an embodiment of the present invention, the curable resin may further include a curable resin other than the bio-curable resin. Here, the other curable resin may be an epoxy resin, specifically, the other curable resin may include at least two epoxy bonds, and more specifically, the other curable resin may be one or more selected from the group consisting of bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, bisphenol AD-type epoxy resin, bisphenol E-type epoxy resin, naphthalene-type epoxy resin, biphenyl-type epoxy resin, dicyclopentadiene-type epoxy resin, phenol novolac-type epoxy resin, alicyclic epoxy resin, and glycidylamine-type epoxy resin.

[0060] According to one embodiment of the present invention, the epoxy resin may have an epoxy equivalent weight (EEW) of 180 g / eq or more and 190 g / eq or less, and a viscosity at 25°C of 8,000 cPs or more and 13,500 cPs or less. Within these ranges, the effectiveness of the structural adhesive can be further improved.

[0061] According to one embodiment of the present invention, the curable resin composition is prepared by dissolving 0.2 g of a curable resin composition sample in acetone, adding 40 mL of methanol, and filtering the supernatant using a 0.22 μm polytetrafluoroethylene filter into a 2 mL liquid chromatography vial. The area ratio of the peaks for the bio-curable resin and the epoxy resin (bio-curable resin:epoxy resin), as measured by elution time using an evaporative light scattering detector (ELSD) using high performance liquid chromatography (HPLC), may be 0.60 to 5.60:1. The area ratio of the peaks for the bio-curable resin and the epoxy resin (bio-curable resin:epoxy resin), as measured by elution time using an evaporative light scattering detector (ELSD) using high performance liquid chromatography (HPLC), may be determined according to the ratio of the bio-curable resin and the epoxy resin present in the curable resin composition. As a specific example, the curable resin composition may have a peak area ratio (bio-curable resin:epoxy resin) of 0.60 or more, 0.65 or more, 0.70 or more, 0.75 or more, 0.80 or more, 0.85 or more, 0.90 or more, 0.95 or more, 1.00 or more, or 1.05 or more:1 for the bio-curable resin and the epoxy resin, as measured by elution time using an evaporative light scattering detector (ELSD) using high performance liquid chromatography (HPLC). The ratio may also be 5.60 or less, 5.50 or less, 5.40 or less, 5.30 or less, 5.20 or less, 5.10 or less, 5.00 or less, 4.90 or less, 4.80 or less, 4.70 or less, 4.60 or less, 4.50 or less, or 4.40 or less.When a mixture of a bio-curable resin and an epoxy resin is used as the curable resin, and the peak area ratio (bio-curable resin:epoxy resin) of each of the bio-curable resin and the epoxy resin, detected by elution time using an evaporative light scattering detector (ELSD) using high performance liquid chromatography (HPLC), is adjusted as described above, an environmentally friendly bio-based epoxy resin is used instead of an existing petroleum-based epoxy resin, thereby reducing environmental pollution and satisfying all of the mechanical strength properties required of a curable resin composition containing an existing petroleum-based epoxy resin. In addition, viscosity can be easily adjusted, and the dispersion efficiency of the graft copolymer in the curable resin can be further improved, thereby further improving productivity and mechanical properties.

[0062] According to one embodiment of the present invention, the curable resin may contain 58 to 82 wt% of a bio-curable resin and 18 to 42 wt% of an epoxy resin. Specifically, the curable resin may contain 58 to 59 wt% of a bio-curable resin, 60 to 61 wt% of a bio-curable resin, 63 to 64 wt% of a bio-curable resin, or 65 to 82 wt% of a bio-curable resin, 81 to 80 wt% of a bio-curable resin, or 80 to 82 wt% of a bio-curable resin, with the remainder being an epoxy resin. When a mixture of a bio-curable resin and an epoxy resin is used as the curable resin, viscosity control is easy and the dispersion efficiency of the graft copolymer in the curable resin can be further improved.

[0063] According to one embodiment of the present invention, the graft copolymer may include a core-shell graft copolymer including a core including a rubber polymer and a shell formed by graft polymerizing a graft monomer onto the rubber polymer.

[0064] According to one embodiment of the present invention, in a core-shell graft copolymer, the "core" may refer to the rubbery polymer component itself that forms the core or core layer of the graft copolymer, and the "shell" may refer to the polymer or copolymer component that is graft-polymerized onto the rubbery polymer to form the shell or shell layer, enclosing the core. That is, the core containing the rubbery polymer may be the rubbery polymer itself, and the shell may refer to the graft layer formed by graft-polymerizing a graft monomer onto the rubbery polymer. According to one embodiment of the present invention, the rubbery polymer is a component that imparts impact resistance when the graft copolymer composition is used as an impact modifier, and may include one or more monomer units selected from the group consisting of conjugated diene-based monomer units and alkyl acrylate-based monomer units. Specifically, the rubbery polymer may be a conjugated diene-based rubbery polymer or an acrylic-based rubbery polymer. As a more specific example, the conjugated diene rubber polymer may be at least one selected from the group consisting of a homopolymer of a conjugated diene monomer and a copolymer of an aromatic vinyl monomer and a conjugated diene monomer, and the acrylic rubber polymer may be a homopolymer of an alkyl acrylate monomer.

[0065] According to one embodiment of the present invention, the conjugated diene monomer of the rubbery polymer may be at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene, and 2-phenyl-1,3-butadiene, and a specific example thereof may be 1,3-butadiene.

[0066] According to one embodiment of the present invention, the aromatic vinyl monomer of the rubbery polymer may be at least one selected from the group consisting of styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, and 1-vinyl-5-hexylnaphthalene, and a specific example thereof may be styrene.

[0067] According to one embodiment of the present invention, the alkyl acrylate monomer of the rubbery polymer may be an alkyl acrylate monomer having 1 to 12 carbon atoms, and a specific example thereof may be at least one selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate, and a more specific example thereof may be n-butyl acrylate.

[0068] According to one embodiment of the present invention, the shell is a component for improving compatibility and mechanical properties when the graft copolymer composition is used as an impact modifier, and as described above, may be a graft layer formed by graft polymerizing a graft monomer onto the rubber polymer. As a specific example, the graft monomer graft polymerized onto the rubber polymer to form the shell may include an alkyl(meth)acrylate monomer.

[0069] According to one embodiment of the present invention, the alkyl(meth)acrylate monomer of the graft monomer may be an alkyl(meth)acrylate monomer having 1 to 12 carbon atoms, and specific examples thereof may be at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate.

[0070] According to one embodiment of the present invention, the alkyl (meth)acrylate monomer of the graft monomer may be two or more monomers selected from the group consisting of alkyl (meth)acrylate monomers having 1 to 12 carbon atoms, and specific examples thereof may be two or more monomers selected from the group consisting of methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate.

[0071] According to one embodiment of the present invention, the alkyl (meth)acrylate monomer of the graft monomer may be a methyl (meth)acrylate monomer and an alkyl (meth)acrylate monomer having 2 to 12 carbon atoms. In this case, the weight-average molecular weight of the shell can be further reduced, thereby minimizing swelling of the shell when the graft copolymer is dispersed in a curable resin, thereby preventing an increase in viscosity. Here, the alkyl (meth)acrylate monomer may include 50 to 99 wt%, 60 to 90 wt%, or 70 to 85 wt% of the methyl (meth)acrylate monomer and 1 to 50 wt%, 10 to 40 wt%, or 15 to 30 wt% of the alkyl (meth)acrylate monomer having 2 to 12 carbon atoms.

[0072] According to one embodiment of the present invention, the graft monomer may further include a crosslinking monomer in addition to the alkyl(meth)acrylate monomer, i.e., the graft monomer may include a methyl(meth)acrylate monomer, a C2-C12 alkyl(meth)acrylate monomer, and a crosslinking monomer.

[0073] According to one embodiment of the present invention, the crosslinkable monomer serves to improve the shell formation ability through crosslinking during the formation of the shell by the graft monomer, and further improve the compatibility and mechanical properties of the shell. The crosslinkable monomer may be at least one selected from (meth)acrylic crosslinkable monomers such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, allyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; and vinyl crosslinkable monomers such as divinylbenzene, divinylnaphthalene, and diallyl phthalate. A specific example of the crosslinkable monomer may be polyethylene glycol diacrylate or allyl methacrylate.

[0074] According to one embodiment of the present invention, the graft monomer may further include an aromatic vinyl-based monomer, that is, the graft monomer may include a methyl (meth)acrylate monomer, an alkyl (meth)acrylate monomer having 2 to 12 carbon atoms, and an aromatic vinyl-based monomer.

[0075] According to one embodiment of the present invention, the aromatic vinyl monomer of the graft monomer may be at least one selected from the group consisting of styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene, and 1-vinyl-5-hexylnaphthalene, and a specific example thereof may be styrene.

[0076] According to an embodiment of the present invention, when the graft monomer further includes an aromatic vinyl monomer, the aromatic vinyl monomer may be included in an amount of 0.1 wt % to 10.0 wt %, 0.5 wt % to 5.0 wt %, or 0.8 wt % to 2.0 wt % based on the total content of the graft monomer.

[0077] In order to enable the curable resin composition of the present invention to be dispersed by a powder dispersion method, it is important to adjust the core content and particle size distribution of the cores in the graft copolymer.

[0078] According to one embodiment of the present invention, the graft copolymer may contain 70% to 92% by weight of the core. Specific examples of the graft copolymer include 70% to 71% by weight, 72% to 73% by weight, 74% to 75% by weight of the core, and 92% to 91% by weight, 90% to 89% by weight, 88% to 87% by weight, 86% to 85% by weight, 84% to 83% by weight, 82% to 81% by weight, or 80% to 90% by weight of the core. Thus, the graft copolymer may contain the shell in an amount of 8 wt% or more, 9 wt% or more, 10 wt% or more, 11 wt% or more, 12 wt% or more, 13 wt% or more, 14 wt% or more, 15 wt% or more, 16 wt% or more, 17 wt% or more, 18 wt% or more, 19 wt% or more, or 20 wt% or less, or 30 wt% or less, 29 wt% or less, 28 wt% or less, 27 wt% or less, 26 wt% or less, or 25 wt% or less. Within this range, when the graft copolymer composition is dispersed in the curable resin, compatibility between the curable resin and the graft copolymer composition is ensured and swelling of the shell is minimized, thereby preventing an increase in viscosity. The respective contents of the core and shell may be determined from the ratio of the rubbery polymer and graft monomer added during the preparation of the graft copolymer.

[0079] According to one embodiment of the present invention, the core may have an average particle size of 100 nm or more and 500 nm or less. Specific examples of the average particle size include 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 260 nm or more, 270 nm or more, 280 nm or more, 290 nm or more, and 300 nm or more. Specific examples of the average particle size include 500 nm or less, 490 nm or less, 480 nm or less, 470 nm or less, 460 nm or less, 450 nm or less, 440 nm or less, 450 nm or less, 460 nm or less, 470 nm or less, 480 nm or less, 490 nm or less, 480 nm or less, 470 nm or less, 460 nm or less, 450 nm or less, 440 nm or less, 45 ... Within this range, when the graft copolymer composition is dispersed in a curable resin, aggregation between small particles can be prevented, and a decrease in dispersibility due to an increase in viscosity can be prevented.

[0080] In this way, by adjusting the core content and core particle size distribution in multiple graft copolymers having different core particle sizes contained in a graft copolymer composition according to the present invention, dispersion in a curable resin composition by a powder dispersion method becomes possible.

[0081] According to one embodiment of the present invention, the shell may have a weight-average molecular weight of 10,000 g / mol or more and 85,000 g / mol or less. Specific examples of the weight-average molecular weight of the shell include 10,000 g / mol or more, 15,000 g / mol or more, 20,000 g / mol or more, 25,000 g / mol or more, 30,000 g / mol or more, 35,000 g / mol or more, and 40,000 g / mol or more. The weight-average molecular weight of the shell may also be 85,000 g / mol or less, 84,000 g / mol or less, 83,000 g / mol or less, 82,000 g / mol or less, 81,000 g / mol or less, 80,000 g / mol or less, or 85,000 g / mol or less. The molecular weight of the shell may be 75,000 g / mol or less, 70,000 g / mol or less, 65,000 g / mol or less, 60,000 g / mol or less, 55,000 g / mol or less, 50,000 g / mol or less, 45,000 g / mol or less, or 40,000 g / mol or less. Within this range, when dispersing the graft copolymer in the curable resin, compatibility between the curable resin and the graft copolymer can be sufficiently ensured and swelling of the shell can be minimized, thereby preventing an increase in viscosity. The weight-average molecular weight of the shell can be adjusted by adjusting the amounts of initiator and activator used when graft polymerizing the graft monomer in the presence of the rubber polymer.

[0082] According to one embodiment of the present invention, the graft copolymer may have an average particle size of 100 nm or more and 600 nm or less. Specific examples of the average particle size include 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 260 nm or more, 270 nm or more, 280 nm or more, 290 nm or more, 300 nm or more, 305 nm or more, 310 nm or more, 315 nm or more, 320 nm or more, and 325 nm or more. Specific examples of the average particle size include 600 nm or less, 590 nm or less, 580 nm or less, 570 nm or less, 560 nm or less, 550 nm or less, 540 nm or less, and the like. The average particle diameter may be 530 nm or less, 520 nm or less, 510 nm or less, 500 nm or less, 490 nm or less, 480 nm or less, 470 nm or less, 460 nm or less, 450 nm or less, 440 nm or less, 430 nm or less, 420 nm or less, 410 nm or less, 400 nm or less, 390 nm or less, 380 nm or less, 370 nm or less, 360 nm or less, 350 nm or less, 340 nm or less, 335 nm or less, 330 nm or less, or 325 nm or less. Within this range, an increase in viscosity can be prevented when dispersing the graft copolymer in a curable resin.

[0083] According to one embodiment of the present invention, the curable resin composition may comprise 50% to 99% by weight of a continuous phase and 1% to 50% by weight of a dispersed phase. Specific examples of the curable resin composition include 50% to 51%, 52%, 53%, 54%, or 55% by weight of a continuous phase, and 99% to 95%, 90% to 85%, 80% to 75%, 70% to 65%, 60% to 55% by weight. In addition, the curable resin composition may contain 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, or 45 wt% or more of the dispersed phase, and may contain 50 wt% or less, 49 wt% or less, 48 ​​wt% or less, 47 wt% or less, 46 wt% or less, or 45 wt% or less.

[0084] The present invention also provides a method for producing the curable resin composition.

[0085] According to one embodiment of the present invention, the method for preparing the curable resin composition includes a step (S10) of preparing a graft copolymer latex containing the graft copolymer, a step (S20) of aggregating and drying the graft copolymer latex prepared in the step (S10) to prepare a graft copolymer powder, and a step (S30) of mixing a curable resin and the graft copolymer powder prepared in the step (S20) to prepare a curable resin composition, and the step (S30) may be performed by dispersing using a stirrer.

[0086] According to one embodiment of the present invention, the step (S10) may be carried out by: (S1) preparing a rubber polymer latex containing a rubber polymer; and (S2) adding a graft monomer in the presence of the rubber polymer latex and graft polymerizing the graft monomer to prepare a graft copolymer latex containing a graft copolymer composition containing a plurality of core-shell graft copolymers.

[0087] According to one embodiment of the present invention, in the method for preparing a curable resin composition, the type and content of the monomer for performing each step may be the same as the type and content of the monomer for the curable resin composition described above.

[0088] According to one embodiment of the present invention, the step (S1) is a step for preparing a rubbery polymer that forms a core or a core layer in a core-shell graft copolymer, and the step (S2) is a step for graft-polymerizing the rubbery polymer to form a shell or a shell layer in the form of a shell that surrounds the core.

[0089] According to one embodiment of the present invention, steps (S1) and (S2) may each be carried out by emulsion polymerization in the presence of an emulsifier and initiator, as well as an electrolyte, a molecular weight modifier, an activator, etc. In carrying out step (S1), the particle size distribution of the rubber polymer particles may be controlled by the amount of emulsifier added.

[0090] According to one embodiment of the present invention, the emulsifier may be at least one selected from the group consisting of fatty acid-based emulsifiers and rosin acid-based emulsifiers, and in this case, it has the effect of providing excellent latex stability.

[0091] According to one embodiment of the present invention, the amount of the emulsifier added in step (S1) may be 0.1 to 3.4 parts by weight, 1.0 to 3.3 parts by weight, 1.5 to 3.2 parts by weight, 2.0 to 3.2 parts by weight, or 2.1 to 3.1 parts by weight, based on 100 parts by weight of the monomer for polymerizing the rubber polymer.

[0092] According to one embodiment of the present invention, the amount of the emulsifier added in step (S2) may be 0.1 to 1.0 parts by weight, 0.1 to 0.5 parts by weight, or 0.1 to 0.3 parts by weight, based on 100 parts by weight of the total of the rubber polymer and the monomer for polymerizing the graft copolymer. Within this range, the effect of excellent latex stability can be obtained.

[0093] According to one embodiment of the present invention, step (S1) may be carried out using a water-soluble initiator that can be used in emulsion polymerization, such as potassium persulfate, sodium persulfate, or ammonium persulfate. Step (S2) may be carried out by radical polymerization using a peroxide-based, redox-based, or azo-based initiator that can be used in emulsion polymerization, such as one or more redox initiators selected from the group consisting of t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, and cumene hydroperoxide, which provides a stable polymerization environment. When using a redox initiator, the process may further include ferrous sulfide, sodium ethylenediaminetetraacetate, and sodium formaldehyde sulfoxylate as redox catalysts serving as activators.

[0094] According to one embodiment of the present invention, step (S2) may be performed by continuously adding the graft monomer. If the graft monomer is added all at once before the start of the graft polymerization reaction in step (S2), the weight average molecular weight of the shell may increase.

[0095] According to one embodiment of the present invention, the emulsion polymerization in the steps (S1) and (S2) may be carried out in an aqueous solvent, and the aqueous solvent may be ion-exchanged water.

[0096] According to one embodiment of the present invention, step (S20) is a step for obtaining the graft copolymer prepared in step (S10) in a powder form, and may be performed by coagulating and drying the graft copolymer latex prepared in step (S10).

[0097] According to one embodiment of the present invention, the coagulation in step (S20) can be performed by adding a coagulant to the graft copolymer latex. The coagulation in step (S20) can be performed using acid coagulation, such as an aqueous sulfuric acid solution, and salt coagulation, such as sodium chloride or sodium sulfate. Both acid and salt coagulation can be performed simultaneously or stepwise. When the coagulation is performed stepwise, acid coagulation can be performed first followed by salt coagulation, or salt coagulation can be performed first followed by acid coagulation. The coagulation in step (S20) can be performed in the presence of an organic dispersant, if necessary.

[0098] According to one embodiment of the present invention, the drying in step (S20) may be carried out by a conventional drying method, and may further include a step of dehydrating the coagulated graft copolymer latex before drying, if necessary.

[0099] According to one embodiment of the present invention, step (S30) is a step of mixing the curable resin and the graft copolymer by the powder dispersion method described above when applying the graft copolymer to the curable resin as an impact modifier, and can be performed by adding the graft copolymer powder to the curable resin and mixing them. As described above, the graft copolymer according to the present invention has excellent powder dispersibility and can be directly dispersed in the curable resin in powder form. As a specific example, the viscosity of the curable resin composition prepared in step (S30) at 25°C can be 2,000 Pa.s or less, 1,900 Pa.s or less, 1,800 Pa.s or less, 1,700 Pa.s or less, 1,600 Pa.s or less, 1,500 Pa.s or less, 1,450 Pa.s or less, 1,400 Pa.s or less, 1,350 Pa.s or less, or 1,300 Pa.s or less. The viscosity may also be 100 Pa s or more, 200 Pa s or more, 300 Pa s or more, 400 Pa s or more, 500 Pa s or more, 600 Pa s or more, 700 Pa s or more, 800 Pa s or more, 900 Pa s or more, 1,000 Pa s or more, 1,100 Pa s or more, or 1,200 Pa s or more. Within this range, the viscosity of the graft copolymer powder is low and the dispersibility is excellent.

[0100] The present invention also provides an adhesive composition comprising the curable resin composition. The adhesive composition may be a structural adhesive composition, and may contain the curable resin composition as a toughening agent.

[0101] According to an embodiment of the present invention, the adhesive composition may include, in addition to the toughening agent, a base agent that can be used as an adhesive, a urethane resin, and a curing agent, and may further include a curing accelerator, a filler, etc.

[0102] According to an embodiment of the present invention, the base resin may include a bio-curable resin similar to the curable resin composition, and the type of the bio-curable resin may be the same as the bio-curable resin of the curable resin composition.

[0103] According to one embodiment of the present invention, the base agent may contain the bio-curable resin in an amount of 1 wt % or more and 40 wt % or less, based on the total content of the adhesive composition. Specific examples of the base agent may contain the bio-curable resin in an amount of 1 wt % or more, 5 wt % or more, 10 wt % or more, 15 wt % or more, or 20 wt % or less, based on the total content of the adhesive composition. The base agent may also contain the bio-curable resin in an amount of 40 wt % or less, 35 wt % or less, or 30 wt % or less, based on the total content of the adhesive composition. Within these ranges, the effectiveness of the structural adhesive may be further improved.

[0104] According to one embodiment of the present invention, the adhesive composition may contain a toughener in an amount of 5 wt% or more and 32 wt% or less, based on the total content of the adhesive composition. Specifically, the adhesive composition may contain a toughener in an amount of 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, or 10 wt% or more, based on the total content of the adhesive composition. Alternatively, the adhesive composition may contain a toughener in an amount of 32 wt% or less, 31 wt% or less, 30 wt% or less, 29 wt% or less, 28 wt% or less, 27 wt% or less, 26 wt% or less, 25 wt% or less, 24 wt% or less, 23 wt% or less, 22 wt% or less, 21 wt% or less, 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, or 15 wt% or less, based on the total content of the adhesive composition. Within this range, the impact strength of adhesives for dissimilar materials, particularly structural adhesive compositions, can be further improved.

[0105] While the present invention may be embodied in various different forms, it is to be understood that the invention is not limited to the specific embodiments set forth herein, and that the invention may be embodied in various different forms without departing from the spirit or scope of the present invention.

[0106] Examples and Comparative Examples Example 1 <Production of rubber polymer latex> In a polymerization reactor (autoclave) purged with nitrogen, 75 parts by weight of ion-exchanged water, 60 parts by weight of 1,3-butadiene, 1.4 parts by weight of potassium rosinate, 0.6 parts by weight of potassium oleate, 0.9 parts by weight of potassium carbonate (K2CO3), 0.3 parts by weight of t-dodecyl mercaptan, and 0.3 parts by weight of potassium persulfate (K2S2O8) were added in one batch relative to 100 parts by weight of 1,3-butadiene, and polymerization was carried out at a reaction temperature of 70°C. Next, when the polymerization conversion rate reached 30% to 40%, 0.7 parts by weight of potassium oleate was added in one batch, followed by 20 parts by weight of 1,3-butadiene, and polymerization was continued at a reaction temperature of 70°C. Then, when the polymerization conversion rate reached 60%, 20 parts by weight of 1,3-butadiene was added all at once, and the reaction temperature was raised to 80°C. Polymerization was continued until the polymerization conversion rate reached 95%. The total polymerization time was 23 hours, and the resulting rubber polymer latex had a gel content of 76%, and the average particle size of the rubber polymer particles was 300nm.

[0107] Here, the polymerization conversion rate was calculated as the ratio of the weight of solid content of the obtained rubber polymer to the weight of solid content of the input monomers.

[0108] <Production of graft copolymer latex> In a sealed polymerization reactor purged with nitrogen, 75 parts by weight of the prepared rubber polymer latex (solids basis) was added to a total of 100 parts by weight of the rubber polymer latex (solids basis), methyl methacrylate, n-butyl acrylate, and styrene, and then 200 parts by weight of ion-exchanged water, 0.2 parts by weight of potassium oleate, 0.036 parts by weight of ferrous sulfide, 0.2 parts by weight of sodium ethylenediaminetetraacetate, 0.2 parts by weight of sodium formaldehyde sulfoxylate, and 0.25 parts by weight of t-butyl hydroperoxide were added all at once. Subsequently, 18 parts by weight of methyl methacrylate, 5 parts by weight of n-butyl acrylate, and 2 parts by weight of styrene were continuously added over 3 hours, and polymerization was carried out at a reaction temperature of 60°C for 4 hours to produce a graft copolymer latex.

[0109] <Production of Graft Copolymer Powder> The prepared graft copolymer latex was diluted with distilled water to 15 wt % based on solids and then placed in a coagulation tank, and the internal temperature of the coagulation tank was raised to 45° C. Next, IR1076 as an antioxidant was added to 100 parts by weight based on the solids of the graft copolymer, and the mixture was coagulated by stirring while adding an aqueous sulfuric acid solution. The graft copolymer and water were separated, and the mixture was dehydrated and dried to prepare a graft copolymer powder.

[0110] <Production of Epoxy Resin Composition Having Graft Copolymer Dispersed> 55 parts by weight of epoxy resin and 45 parts by weight of the prepared graft copolymer powder were added to a planetary mixer (KMTECH, KPLM-0.6) set at 70°C, based on a total of 100 parts by weight of epoxy resin and graft copolymer, and the mixture was stirred at 10 rpm for 1 hour, 80 rpm for 2 hours, and 60 rpm for 10 hours to disperse the graft copolymer powder in the epoxy resin, thereby preparing an epoxy resin composition in which the graft copolymer was dispersed.

[0111] The epoxy resin used was a mixture of 65 wt % isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) and 35 wt % bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.).

[0112] <Production of structural adhesive composition> 30 parts by weight of isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) and 25.4 parts by weight of bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) as the base resin, 15 parts by weight of the epoxy resin composition prepared above as the toughening agent, 20 parts by weight of urethane resin (QR-9466, manufactured by Adeka Co., Ltd.) as the toughening agent, 4.9 parts by weight of hardener (Dicyanex 1400F, manufactured by Evonik Co., Ltd.) as the hardening accelerator (Amicure UR7 / 10, manufactured by Evonik Co., Ltd.) as the hardening accelerator, 3.0 parts by weight of calcium oxide (UNI-OX, manufactured by YOUYEONG Materials Co., Ltd.) as the hardening accelerator, and 1.0 part by weight of fumed silica (CAB-O-SIL TS-720, manufactured by Cabot Co., Ltd.) as the hardening agent were mixed in a paste mixer. The adhesive composition was prepared by mixing the components for 3 minutes at 600 rpm revolution and 500 rpm rotation using a mixer (KM TECH, PDM-300) and then degassing for 5 minutes at 600 rpm revolution and 200 rpm rotation. Here, the curing agent was added in accordance with the equivalent weight of the epoxy resin, and the curing accelerator was added in an equivalent ratio of 1 / 7 of the curing agent.

[0113] Example 2 An epoxy resin composition was prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 70 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 30 wt % instead of 35 wt %.

[0114] In addition, an adhesive composition was prepared in the same manner as in Example 1, except that, when preparing the structural adhesive composition in Example 1, 40 parts by weight of an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 30 parts by weight, 15.4 parts by weight of a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 25.4 parts by weight, and the same amount of the prepared epoxy resin composition was added as the toughening agent.

[0115] Example 3 An epoxy resin composition was prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 80 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 20 wt % instead of 35 wt %.

[0116] In addition, an adhesive composition was prepared in the same manner as in Example 1, except that, when preparing the structural adhesive composition in Example 1, 20 parts by weight of an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 30 parts by weight, 35.4 parts by weight of a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 25.4 parts by weight, and the same amount of the prepared epoxy resin composition was added as the toughening agent.

[0117] Example 4 An epoxy resin composition was prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was used in an amount of 70 wt % instead of 65 wt %, and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was used in an amount of 30 wt % instead of 35 wt %, and 50 parts by weight of the epoxy resin was added instead of 55 parts by weight, and 50 parts by weight of the prepared graft copolymer powder was added instead of 45 parts by weight.

[0118] In addition, an adhesive composition was prepared in the same manner as in Example 1, except that 30.4 parts by weight of a bisphenol-A based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 25.4 parts by weight, and 10 parts by weight of the prepared epoxy resin composition was added as a toughening agent.

[0119] Example 5 A rubber polymer latex was prepared in the same manner as in Example 1, except that 50 parts by weight of ion-exchanged water was added instead of 75 parts by weight, and 1.8 parts by weight of potassium carbonate (KCO) was added instead of 0.9 parts by weight.

[0120] In addition, an epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 70 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 30 wt % instead of 35 wt %.

[0121] Example 6 The same procedure as in Example 1 was carried out to prepare a graft copolymer latex, except that the prepared rubber polymer latex was added in an amount of 90 parts by weight instead of 75 parts by weight based on the solid content, methyl methacrylate was added in an amount of 7 parts by weight instead of 18 parts by weight, n-butyl acrylate was added in an amount of 2 parts by weight instead of 5 parts by weight, and styrene was added in an amount of 1 part by weight instead of 2 parts by weight.

[0122] In addition, an epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 70 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 30 wt % instead of 35 wt %.

[0123] Example 7 A graft copolymer latex was prepared in the same manner as in Example 1, except that 0.1 parts by weight of potassium oleate instead of 0.2 parts by weight and 0.125 parts by weight of t-butyl hydroperoxide instead of 0.25 parts by weight were added during the preparation of the graft copolymer latex.

[0124] In addition, an epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 70 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kookdo Chemical Co., Ltd.) was mixed at 30 wt % instead of 35 wt %.

[0125] Example 8 An adhesive composition was prepared in the same manner as in Example 1, except that, when preparing the structural adhesive composition in Example 1, 25 parts by weight of an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 30 parts by weight, 15.4 parts by weight of a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was added as the main component instead of 25.4 parts by weight, and 30 parts by weight of the prepared epoxy resin composition was added as the toughening agent.

[0126] Comparative Example 1 An epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was mixed at 85 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was mixed at 15 wt % instead of 35 wt % when preparing the epoxy resin composition.

[0127] Comparative Example 2 An epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was mixed at 50 wt % instead of 65 wt % and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was mixed at 50 wt % instead of 35 wt % when preparing the epoxy resin composition.

[0128] Comparative Example 3 An epoxy resin composition and an adhesive composition were prepared in the same manner as in Example 1, except that an isosorbide-based epoxy resin (KDBM-1040, manufactured by Kukdo Chemical Co., Ltd.) was not added as the epoxy resin in the preparation of the epoxy resin composition in Example 1, and a bisphenol-A-based epoxy resin (YD-128, manufactured by Kukdo Chemical Co., Ltd.) was used alone.

[0129] Experimental Example 1 For the rubber polymers and graft copolymers prepared in Examples 1 to 8 and Comparative Examples 1 to 3, the average particle diameters of the core and graft copolymer and the weight average molecular weight of the shell were measured by the following methods, and the results are shown in Tables 1 and 2 below, along with the contents of each component.

[0130] *Average particle size (nm) of core and graft copolymer: The rubber polymer latex and graft copolymer latex prepared in Examples 1 to 8 and Comparative Examples 1 to 7 were each diluted with distilled water to a concentration of 200 ppm, and then measured by dynamic light scattering (DLS) method according to ISO 22412 using NICOMP 380.

[0131] *Shell weight average molecular weight (g / mol): The shell weight average molecular weight of the obtained core-shell graft copolymer was measured by gel permeation chromatography (GPC, PL GPC220, Agilent Technologies) under the following conditions.

[0132] Here, the sample was prepared by taking a portion of the graft copolymer solution dispersed in tetrahydrofuran, separating the precipitate using a centrifuge, and then filtering the supernatant through a 0.45 μm PTFE syringe filter to use as the sample solution. The sample was sampled at a concentration of 30.0 mg / mL for the graft copolymer and 1.5 mg / mL for the linear polymer.

[0133] -Column: PL MiniMixed B x 2 -Solvent: Tetrahydrofuran (Stabilized with BHT) -Flow rate: 1.0mL / min -Sample concentration: 1.0 mg / mL -Injection volume: 100μl -Column temperature: 30℃ -Detector: Waters 2414 Refractive Index Detector -Data processing: Empower 3

[0134] [Table 1]

[0135] [Table 2]

[0136] Experimental Example 2 For the epoxy resin compositions in which the graft copolymers are dispersed, which are curable resin compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3, the dispersion state of the graft copolymers was confirmed by the following method, and the viscosity was measured. The area ratios of the peaks for the bio-curable resin and the epoxy resin measured using an evaporative light scattering detector of high performance liquid chromatography were calculated, and the results are shown in Tables 3 and 4 below, along with the contents of each component.

[0137] *Dispersion state: An epoxy resin composition was applied to a 25mm x 100mm cold-rolled (CR) steel plate to a thickness of 0.2mm, and the number of particles observed with the naked eye was counted. Here, a number of particles less than 10 observed with the naked eye indicates an excellent dispersion state, 10 to less than 50 particles indicates an average dispersion state, and 50 or more particles indicates a poor dispersion state.

[0138] * Viscosity at 25°C (Pa.s): The viscosity of the epoxy resin composition prepared above was measured at 25°C using a rheometer (MRC 302, manufactured by Anton Paar), and the shear rate was 2.4 s. -1 The viscosity values ​​at 100 s are shown.

[0139] *Peak area ratio: 0.2 g of the prepared epoxy resin composition sample was dissolved in acetone, and 40 mL of methanol was added. The supernatant was filtered into a 2 mL liquid chromatography vial using a 0.22 μm polytetrafluoroethylene (PTFE) filter. Using high-performance liquid chromatography (HPLC), the peak areas for the bio-curable resin and the epoxy resin, detected by elution time using an evaporative light scattering detector (ELSD), were determined. The peak area ratio (bio-curable resin:epoxy resin) for the bio-curable resin and the epoxy resin was then calculated.

[0140] [Table 3]

[0141] [Table 4]

[0142] As shown in Table 3, all of the curable resin compositions of Examples 1 to 8 produced according to the present invention had excellent dispersion states, and exhibited viscosities at 25°C of 1,200 Pa s or more and 1,900 Pa s or less, confirming that the compositions were excellently dispersed despite being dispersed in a powder form.

[0143] On the other hand, as shown in Table 4, the curable resin composition prepared in Comparative Example 1 was prepared as a gel dispersion with no fluidity, rather than a liquid dispersion, and it was confirmed that the graft copolymer was not dispersed in a powder form.

[0144] In addition, it was confirmed that the curable resin composition prepared in Comparative Example 2 had an increased epoxy resin content equal to the bio-curable resin content, while the curable resin composition prepared in Comparative Example 3 contained only an epoxy resin without containing a bio-curable resin, and therefore had a decreased dispersibility.

[0145] Experimental Example 3 The shear strength and impact peel strength of the structural adhesive compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were measured by the following methods, and the results, along with the contents of each component, are shown in Tables 5 and 6 below.

[0146] *Shear strength (Lap Shear, MPa): The shear strength of the prepared structural adhesive composition was measured according to ASTM D1002. The size of the test specimen was 180 mm x 25.4 mm x 1.6 mm, and the size of one side to which the adhesive composition was applied was 25.4 mm x 12.5 mm. After removing contaminants from one side of the test specimen using ethanol, the prepared structural adhesive composition was applied. The thickness of the adhesive composition was maintained constant using microbeads, and another test specimen was placed on top and fixed, followed by curing at 180°C for 30 minutes. After curing, the shear strength was measured by applying a load at a rate of 1.3 mm / min using a UTM testing machine (Instron, 5900).

[0147] *Impact peel strength (N / mm): The impact peel strength of the prepared structural adhesive composition was measured in accordance with ISO 11343. The test specimen dimensions were 90 mm x 20 mm x 1.6 mm, and the surface to which the adhesive composition was applied was 30 mm x 20 mm. After removing contaminants from one side of the test specimen using ethanol, the prepared structural adhesive composition was applied. The thickness of the adhesive composition was maintained constant using microbeads, and another test specimen was placed on top of it to secure it in place. The adhesive composition was then cured at 180°C for 30 minutes. After curing, the specimens were allowed to stabilize at 25°C and -40°C for at least one hour, and the impact peel strength was measured using an impact strength tester (Instron, 9350) by applying a load at a rate of 2 m / sec.

[0148] [Table 5]

[0149] [Table 6]

[0150] As shown in Table 5, it was confirmed that all of the structural adhesive compositions of Examples 1 to 8, which contained the curable resin composition prepared according to the present invention as a toughening agent and a bio-curable resin as a base resin, were excellent in shear strength and impact peel strength.

[0151] On the other hand, it was confirmed that the structural adhesive composition prepared using the curable resin composition of Comparative Example 1, in which an excessive amount of bio-curable resin was used in the curable resin during preparation of the curable resin composition, had reduced shear strength and impact peel strength because the graft copolymer was not dispersed in the curable resin composition.

[0152] In addition, it was confirmed that the structural adhesive compositions prepared using the curable resin compositions of Comparative Example 2, in which the same amounts of bio-curable resin and epoxy resin were used in the curable resin when preparing the curable resin composition, and Comparative Example 3, in which only epoxy resin was used without using any curable resin, did not have the graft copolymer dispersed in the curable resin composition, and therefore both the shear strength and impact peel strength were reduced.

Claims

1. a continuous phase comprising a curable resin and a dispersed phase comprising a graft copolymer; the curable resin includes a bio-curable resin and an epoxy resin; A 0.2 g sample of the curable resin composition is dissolved in acetone, 40 mL of methanol is added, and the supernatant is filtered into a 2 mL liquid chromatography vial using a 0.22 μm polytetrafluoroethylene filter. Using high performance liquid chromatography (HPLC), the area ratio of the peaks for the biocurable resin and the epoxy resin (biocurable resin:epoxy resin) detected based on elution time using an evaporative light scattering detector (ELSD) is 0.60 to 5.60:

1. This curable resin composition.

2. The curable resin composition according to claim 1 , wherein the bio-curable resin is a bio-epoxy resin.

3. The curable resin composition of claim 1 , wherein the bio-curable resin comprises isosorbide units.

4. The curable resin composition according to claim 1 , wherein the bio-curable resin is represented by the following chemical formula 1: 【Transformation 3】 In the above Chemical Formula 1, R 1 and R 2 are each independently a hydrogen atom, a hydroxy group, an epoxy group, or a glycidyl group; n is an integer selected from 1 to 1,000.

5. The curable resin composition according to claim 1, wherein the bio-curable resin has an epoxy equivalent weight (EEW) of 150 g / eq or more and 190 g / eq or less.

6. The curable resin composition according to claim 1 , wherein the bio-curable resin has a viscosity at 25° C. of 500 cPs or more and 6,000 cPs or less.

7. 2. The curable resin composition according to claim 1, wherein the epoxy resin comprises at least one selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, bisphenol E type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, dicyclopentadiene type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins, and glycidyl amine type epoxy resins.

8. The curable resin composition according to claim 1, wherein the epoxy resin has an epoxy equivalent (EEW) of 180 g / eq or more and 190 g / eq or less.

9. The curable resin composition according to claim 1 , wherein the epoxy resin has a viscosity at 25° C. of 8,000 cPs or more and 13,500 cPs or less.

10. 2. The curable resin composition of claim 1, wherein the curable resin comprises 58% by weight or more and 82% by weight or less of a bio-curable resin and 18% by weight or more and 42% by weight or less of an epoxy resin.

11. 2. The curable resin composition according to claim 1, wherein the graft copolymer comprises a core-shell graft copolymer including a core containing a rubber polymer and a shell formed by graft polymerizing a graft monomer onto the rubber polymer.

12. The curable resin composition according to claim 11, wherein the rubbery polymer comprises one or more monomer units selected from the group consisting of conjugated diene-based monomer units and alkyl acrylate-based monomer units.

13. The curable resin composition according to claim 11 , wherein the grafting monomer comprises an alkyl (meth)acrylate monomer.

14. The curable resin composition according to claim 11, wherein the graft monomer comprises a methyl(meth)acrylate monomer and an alkyl(meth)acrylate monomer having 2 to 12 carbon atoms.

15. The curable resin composition according to claim 11 , wherein the graft monomer further comprises an aromatic vinyl monomer.

16. The curable resin composition according to claim 11 , wherein the graft copolymer comprises 70% by weight or more and 92% by weight or less of a core and 8% by weight or more and 30% by weight or less of a shell.

17. The curable resin composition according to claim 11, wherein the core has an average particle size of 100 nm or more and 500 nm or less.

18. The curable resin composition according to claim 11, wherein the shell has a weight average molecular weight of 10,000 g / mol or more and 85,000 g / mol or less.

19. The curable resin composition according to claim 11, wherein the graft copolymer has an average particle size of 100 nm to 600 nm.

20. An adhesive composition comprising the curable resin composition according to any one of claims 1 to 19.