Graft copolymer composition, curable resin composition containing the same, and production method thereof

Abstract

The present invention relates to a graft copolymer, and more particularly to a graft copolymer composition which has excellent powder dispersibility in curable resins such as epoxy resins and can be used as a powder-phase impact modifier, a curable resin composition containing the same, and methods for producing the same.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0107588, filed on August 13, 2021, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety. The present invention relates to a graft copolymer composition having excellent powder dispersibility in curable resins such as epoxy resins and applicable as a powder phase impact reinforcing agent, a curable resin composition containing the same, and methods for producing them.

Background Art

[0002] Curable resins typified by epoxy resins are used in various fields such as electric and electronic products, automotive parts, and building materials. For the purpose of complementing physical properties, processability, etc. rather than being used alone, additives such as inorganic fillers, release agents, and rubber fine particles having rubbery properties are used in combination. Among these, epoxy resins often exhibit brittle properties, so improvement in impact resistance and adhesive strength is required.

[0003] As a solution for improving the impact resistance of epoxy resins, a solution of using a graft copolymer containing a rubbery polymer as an impact reinforcing agent in combination has been proposed. The graft copolymer has a core - shell structure particle shape including a core containing a rubbery polymer and a shell formed by graft polymerization on the core.

[0004] Here, in order to apply the graft copolymer as an impact reinforcing agent for epoxy resins, it is necessary to disperse the graft copolymer in the epoxy resin. As methods for dispersing the graft copolymer in the epoxy resin, there are a liquid - phase dispersion method and a powder - phase dispersion method.

[0005] As shown in Fig. 1, in the liquid-phase dispersion method, the graft copolymer is dispersed in an epoxy resin by a stepwise solvent replacement method in which water is replaced with a solvent and then the solvent is replaced again with an epoxy resin for a latex-like graft copolymer in which the graft copolymer is dispersed in water. Such a liquid-phase dispersion method has the advantage that the graft copolymer is dispersed in a homogeneous distribution matrix of the epoxy resin. However, in order to apply the graft copolymer as an impact reinforcing agent to the epoxy resin, there is a storage problem in that the graft copolymer must be stored in a latex state until it is dispersed, the process cost due to solvent replacement is high, and there are environmental problems due to the graft copolymer and the water and solvent separated and discharged in the solvent replacement process.

[0006] As shown in Fig. 2, in the powder-phase dispersion method, since the dried powder aggregated from the graft copolymer latex, that is, the graft copolymer in the powder phase, is directly dispersed in the epoxy resin, it has the advantage of low process cost. However, when the graft copolymer powder is directly introduced into the epoxy resin, the viscosity of the graft copolymer powder becomes very high, so there is a problem that dispersion is substantially very difficult or impossible.

[0007] Therefore, in order to apply an impact reinforcing agent to a curable resin composition such as an epoxy resin and apply the powder-phase dispersion method to improve all aspects of process cost and environment, it is necessary to improve the powder dispersibility of the graft copolymer powder.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been devised to solve the problems of the prior art, and provides a graft copolymer composition excellent in powder dispersibility for curable resins such as epoxy resins and applicable as a powder phase impact reinforcing agent, and a method for producing the same.

[0010] Further, the present invention aims to provide a curable resin composition in which the graft copolymer composition is applied to the powder phase and a method for producing the same.

Means for Solving the Problems

[0011] To solve the above problems, the present invention provides a graft copolymer composition, a curable resin composition, and a method for producing a curable resin composition.

[0012] 1) The present invention provides a graft copolymer composition containing a plurality of graft copolymers having different core particle diameters, wherein the graft copolymer is a core-shell graft copolymer including a core containing a rubbery polymer; and a shell formed by graft polymerization of a graft monomer containing an alkyl (meth) acrylate monomer onto the rubbery polymer, the plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of the core, and the number of rubber particles observed when magnified 15,000 times using a transmission electron microscope for a specimen in which 8 parts by weight of a dispersion phase containing the graft copolymer composition is dispersed with respect to 100 parts by weight of a continuous phase containing a curable resin is 200 or more and 500 or less.

[0013] 2) The present invention provides a graft copolymer composition containing a plurality of graft copolymers having different core particle diameters, wherein the graft copolymer is a core-shell graft copolymer including a core containing a rubbery polymer; and a shell formed by graft polymerization of a graft monomer containing an alkyl (meth) acrylate monomer onto the rubbery polymer, the plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of the core, and the core satisfies the following (1) to (3) in terms of the particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation). (1) Core particles having a particle size of 30 nm or more and less than 100 nm: 0 wt% or more and 4 wt% or less, (2) Core particles having a particle size of 100 nm or more and less than 350 nm: 50 wt% or more and 94 wt% or less, (3) Core particles having a particle size of 350 nm or more and 550 nm or less: 6 wt% or more and 50 wt% or less

[0014] 3) The present invention provides a graft copolymer composition in which, in the above 1), the core has a particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation) satisfying the following (1) to (3). (1) Core particles having a particle size of 30 nm or more and less than 100 nm: 0 wt% or more and 4 wt% or less, (2) Core particles having a particle size of 100 nm or more and less than 350 nm: 50 wt% or more and 94 wt% or less, (3) Core particles having a particle size of 350 nm or more and 550 nm or less: 6 wt% or more and 50 wt% or less

[0015] 4) The present invention provides a graft copolymer composition in which, in any one of the above 1) to 3), 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.

[0016] 5) The present invention provides a graft copolymer composition in which, in any one of the above 1) to 4), the graft monomer contains methyl (meth) acrylate monomer, an alkyl (meth) acrylate monomer having 2 to 12 carbon atoms, and a crosslinkable monomer.

[0017] 6) The present invention provides a graft copolymer composition in which, in the above 5), the crosslinkable monomer is polyethylene glycol diacrylate or allyl methacrylate.

[0018] 7) The present invention provides a graft copolymer composition in which, in any one of the above 1) to 6), the graft monomer further contains an aromatic vinyl-based monomer.

[0019] 8) In any one of the above 1) to 7), the present invention provides a graft copolymer composition in which the plurality of graft copolymers contain 75% by weight or more and 85% by weight or less of the core and 15% by weight or more and 25% by weight or less of the shell.

[0020] 9) In any one of the above 1) to 8), the present invention provides a graft copolymer composition in which the average particle diameter of the core of the plurality of graft copolymers is 250 nm or more and 350 nm or less.

[0021] 10) In any one of the above 1) to 9), for a specimen in which 8 parts by weight of a dispersion phase containing a graft copolymer composition are dispersed in 100 parts by weight of a continuous phase containing a curable resin, when magnified 15,000 times using a transmission electron microscope, the present invention provides a graft copolymer composition in which the particle size distribution of the rubber particles observed satisfies the following (4) to (6). (4) 0 number % or more and 5 number % or less of rubber particles having a particle size of 30 nm or more and less than 100 nm, (5) 50 number % or more and 95 number % or less of rubber particles having a particle size of 100 nm or more and less than 350 nm, (6) 5 number % or more and 50 number % of rubber particles having a particle size of 350 nm or more and 550 nm or less

[0022] 11) In any one of the above 1) to 10), the present invention provides a graft copolymer composition in which the curable resin is an epoxy resin.

[0023] 12) The present invention provides a curable resin composition including a continuous phase and a dispersion phase, wherein the continuous phase contains a curable resin and the dispersion phase contains a graft copolymer composition according to any one of 1) to 11).

[0024] 13) In the above 12), the present invention provides a curable resin composition containing 50% by weight to 99% by weight of the continuous phase and 1% by weight to 50% by weight of the dispersion phase.

[0025] 14) The present invention provides a method for producing a curable resin composition, including the steps of: preparing a graft copolymer latex containing the graft copolymer composition according to any one of the above 1) to 10) (S10); aggregating and drying the graft copolymer latex prepared in the step (S10) to produce a graft copolymer powder (S20); and mixing a curable resin and the graft copolymer powder produced in the step (S20) to produce a curable resin composition (S30), wherein the step (S30) is carried out by dispersion using a stirrer.

[0026] 15) The present invention provides a method for producing a curable resin composition, which in the above 14), the viscosity of the curable resin composition produced in the step (S30) is 2,000 Pa·s or less at 25°C.

Advantages of the Invention

[0027] The graft copolymer composition of the present invention has excellent powder dispersibility in curable resins such as epoxy resins, and has the effect that it can be dispersed in the curable resin composition by a powder phase dispersion method.

[0028] The curable resin composition of the present invention can apply the graft copolymer composition as an impact reinforcing agent in the powder phase, has excellent productivity, and has the effect that the mechanical properties such as impact resistance are excellent due to the graft copolymer composition dispersed in the curable resin composition.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0030] Hereinafter, the present invention will be described in more detail to facilitate understanding of the present invention. Terms and words used in the description and claims of the present invention should not be construed as being limited to their ordinary and dictionary meanings. In accordance with the principle that the inventor himself can appropriately define the concept of the terms in order to explain the invention in the best way, they must be construed in a meaning and concept that conforms to the technical idea of the present invention.

[0031] In the present invention, the term "monomer unit" may refer to a component, structure, or the substance itself derived from a monomer. As a specific example, it may mean a repeating unit formed by the monomer introduced during the polymerization of a polymer participating in the polymerization reaction in the polymer.

[0032] The term "composition" used in the present invention includes not only reaction products and decomposition products formed from the materials of the composition, but also mixtures of materials containing the composition.

[0033] The present invention provides a graft copolymer composition that can be applied as an impact reinforcing agent to a curable resin composition. The graft copolymer composition according to the present invention has improved powder dispersibility in a curable resin such as an epoxy resin, and includes a plurality of graft copolymers having different core particle sizes. The graft copolymer is a core-shell type graft copolymer including a core containing a rubbery polymer; and a shell formed by graft polymerization of a graft monomer containing an alkyl (meth)acrylate monomer on the rubbery polymer. The plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of the core. With respect to a specimen in which 8 parts by weight of a dispersion phase containing the graft copolymer composition is dispersed in 100 parts by weight of a continuous phase containing a curable resin, the number of rubber particles observed when magnified 15,000 times using a transmission electron microscope may be 200 or more and 500 or less. The number of the rubber particles observed using a transmission electron microscope with respect to the specimen may mean the powder dispersibility when the graft copolymer is dispersed in the curable resin composition by a powder phase dispersion method. When the number of rubber particles satisfies the above range, it is considered that the graft copolymer composition has excellent powder dispersibility in a curable resin such as an epoxy resin.

[0034] According to one embodiment of the present invention, the graft copolymer composition includes a plurality of graft copolymers having different core particle sizes. The graft copolymer is a core-shell type graft copolymer including a core containing a rubbery polymer; and a shell formed by graft polymerization of a graft monomer containing an alkyl (meth)acrylate monomer on the rubbery polymer. The plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of the core. The core may satisfy the following (1) to (3) in terms of the particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation). Thereby, there is an effect that it is possible to disperse in the curable resin composition by a powder phase dispersion method. (1) 0% by weight or more and 4% by weight or less of core particles having a particle size of 30 nm or more and less than 100 nm, (2) 50% by weight or more and 94% by weight or less of core particles having a particle size of 100 nm or more and less than 350 nm, (3) Core particles having a particle size of 6% by weight or more and 50% by weight or less and more than 350 nm and less than 550 nm

[0035] According to an embodiment of the present invention, in a specimen in which 8 parts by weight of a dispersed phase containing the graft copolymer composition is dispersed in 100 parts by weight of a continuous phase containing a curable resin, the number of rubber particles observed when magnified 15,000 times using a transmission electron microscope is 200 or more and 500 or less, and the plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of a core, and the core may simultaneously satisfy the particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation) satisfying the above (1) to (3).

[0036] According to an embodiment of the present invention, in a specimen in which 8 parts by weight of a dispersed phase containing the graft copolymer composition is dispersed in 100 parts by weight of a continuous phase containing the curable resin, the number of rubber particles observed when magnified 15,000 times using a transmission electron microscope may be 200 or more, 210 or more, 220 or more, 230 or more, 240 or more, 250 or more, 260 or more, 270 or more, 280 or more, 290 or more, 300 or more, 350 or more, 400 or more, or 450 or more, and may also be 500 or less, 490 or less, 480 or less, 470 or less, 460 or less, 450 or less, 400 or less, 350 or less, 300 or less, 290 or less, 280 or less, 270 or less, 260 or less, or 250 or less. This range relates to an appropriate range of the number of rubber particles when the graft copolymer composition is dispersed in a continuous phase containing a curable resin. Since the distance between rubber particles dispersed in a curable resin composition containing the graft copolymer composition as a dispersed phase can be most effectively adjusted within this range, both the dispersion viscosity and mechanical properties have excellent effects.

[0037] According to one embodiment of the present invention, in the core-shell graft copolymer, the core may mean the rubbery polymer component itself that forms the core or core layer of the graft copolymer, and the shell may mean a polymer component or copolymer component that graft-polymerizes onto the rubbery polymer to form a shell or shell layer in a shell shape that wraps the core. That is, the core containing the rubbery polymer may be the rubbery polymer itself, and the shell may mean a graft layer formed by graft-polymerizing a graft monomer onto the rubbery polymer.

[0038] According to one embodiment of the present invention, when applying the graft copolymer composition as an impact reinforcing agent, the rubbery polymer may contain one or more monomer units selected from the group consisting of conjugated diene-based monomer units and alkyl acrylate-based monomer units as components for imparting impact resistance. As a specific example, the rubbery polymer may be a conjugated diene-based rubbery polymer or an acrylic rubbery polymer. As a more specific example, the conjugated diene-based rubbery polymer may be one or more selected from the group consisting of a homopolymer of a conjugated diene-based monomer and a copolymer of an aromatic vinyl-based monomer - conjugated diene-based monomer, and the acrylic rubbery polymer may be a homopolymer of an alkyl acrylate-based monomer.

[0039] According to one embodiment of the present invention, the conjugated diene-based monomer of the rubbery polymer may be one or more 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 as a specific example, it may be 1,3-butadiene.

[0040] 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 as a specific example, it may be styrene.

[0041] 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 as a specific example, it may be at least one selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate, and as a more specific example, it may be n-butyl acrylate.

[0042] According to one embodiment of the present invention, when the shell applies the graft copolymer composition as an impact reinforcing agent, it is a component for improving compatibility and mechanical physical properties, and as described above, it may be a graft layer formed by graft polymerization of a graft monomer onto the rubbery polymer. As a specific example, the graft monomer graft-polymerized onto the rubbery polymer to form the shell may include an alkyl (meth)acrylate monomer.

[0043] 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 as a specific example, it 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.

[0044] 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. Specific examples may include two or more 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.

[0045] 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, since the weight average molecular weight of the shell can be made lower, when the graft copolymer is dispersed in the curable resin, swelling of the shell can be minimized, thereby preventing an increase in viscosity. At this time, the alkyl (meth) acrylate monomer may contain 50% to 99% by weight, 60% to 90% by weight, or 70% to 85% by weight of the methyl (meth) acrylate monomer; and 1% to 50% by weight, 10% to 40% by weight, or 15% to 30% by weight of the alkyl (meth) acrylate monomer having 2 to 12 carbon atoms.

[0046] According to one embodiment of the present invention, the graft monomer may further contain a crosslinkable monomer in addition to the alkyl (meth) acrylate monomer. That is, the graft monomer may contain a methyl (meth) acrylate monomer, an alkyl (meth) acrylate monomer having 2 to 12 carbon atoms, and a crosslinkable monomer.

[0047] According to one embodiment of the present invention, when forming a shell with the graft monomer, the crosslinkable monomer is used to improve the shell-forming ability by crosslinking, and at the same time, to further improve the compatibility and mechanical properties of the shell. It may be one or more 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. As a specific example, it may be polyethylene glycol diacrylate or allyl methacrylate.

[0048] According to one embodiment of the present invention, the graft monomer may further contain an aromatic vinyl monomer. That is, the graft monomer may contain a methyl (meth)acrylate monomer, an alkyl (meth)acrylate monomer having 2 to 12 carbon atoms, and an aromatic vinyl monomer.

[0049] According to one embodiment of the present invention, the aromatic vinyl monomer of the graft monomer may be one or more 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. As a specific example, it may be styrene.

[0050] According to one embodiment of the present invention, when the graft monomer further contains an aromatic vinyl monomer, the aromatic vinyl monomer may be contained 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.

[0051] In the graft copolymer composition according to the present invention, in order to enable dispersion in the curable resin composition by the powder phase dispersion method, it is very important to adjust the content of the core and the particle size distribution of the core in a plurality of graft copolymers having different core particle sizes contained in the graft copolymer composition.

[0052] According to one embodiment of the present invention, the plurality of graft copolymers may contain 75% by weight or more and 90% by weight or less of the core. As a specific example, the plurality of graft copolymers may contain 75% by weight or more, 76% by weight or more, 77% by weight or more, 78% by weight or more, 79% by weight or more, or 80% by weight or more of the core, and may also contain 90% by weight or less, 89% by weight or less, 88% by weight or less, 87% by weight or less, 85% by weight or less, 84% by weight or less, 83% by weight or less, 82% by weight or less, 81% by weight or less, or 80% by weight or less of the core. Thereby, the plurality of graft copolymers may contain 10% by weight or more, 11% by weight or more, 12% by weight or more, 13% by weight or more, 14% by weight or more, 15% by weight or more, 16% by weight or more, 17% by weight or more, 18% by weight or more, 19% by weight or more, or 20% by weight or more of the shell, and may also contain 25% by weight or less, 24% by weight or less, 23% by weight or less, 22% by weight or less, 21% by weight or less, or 20% by weight or less of the shell. When dispersing the graft copolymer composition in the curable resin within this range, while sufficiently ensuring the compatibility between the curable resin and the graft copolymer composition, by minimizing the swelling of the shell, an increase in viscosity can be prevented. On the other hand, when the graft copolymer composition contains the core in a content lower than the above range, since the content of the shell in the graft copolymer can only increase, there is a problem that the shell having high affinity with the curable resin swells, the viscosity increases, and the dispersibility decreases. Further, when the graft copolymer composition contains the core in a content higher than the above range, the compatibility between the curable resin and the graft copolymer composition rapidly decreases, and although the increase in viscosity due to the swelling of the shell can be prevented, there is a problem that dispersion is not substantially performed. On the other hand, the respective contents of the core and the shell may be derived from the ratio of the content of the rubbery polymer and the graft monomer charged during the production of the graft copolymer composition.

[0053] According to one embodiment of the present invention, the plurality of graft copolymers may have different core particle sizes, and such cores may have a particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation) that satisfies the above (1) to (3).

[0054] According to one embodiment of the present invention, the condition of (1) is a distribution with respect to the content of small core particles having a particle size of 30 nm or more and less than 100 nm among the cores. The core particles having a particle size of 30 nm or more and less than 100 nm may be 0 wt% or more, 1 wt% or more, 2 wt% or more, or 3 wt% or more, and may also be 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, or 0 wt%. Thus, in a plurality of graft copolymers with different core particle sizes, when the condition of (1) is satisfied in the particle size distribution of the cores, by minimizing or eliminating the content of small core particles, there is an effect that the viscosity can be lowered when the graft copolymer composition is dispersed in the curable resin. Here, although the range of small core particles having a particle size of 30 nm or more and less than 100 nm is referred to, this is not intended to exclude small core particles having a particle size of less than 30 nm. The above particle size range is for indicating the particle size range of small core particles showing the minimum particle size among the core particles.

[0055] According to an embodiment of the present invention, the condition of (2) is a distribution with respect to the content of medium-sized core particles having a particle size of 100 nm or more and less than 350 nm in the core, and the core particles having a particle size of 100 nm or more and less than 350 nm may be 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, or 90 wt% or more, and may also be 94 wt% or less, 93 wt% or less, 92 wt% or less, 91 wt% or less, 90 wt% or less, 85 wt% or less, 80 wt% or less, 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less, or 55 wt% or less. Thus, when a plurality of graft copolymers having different core particle sizes satisfy the condition of (2) in the particle size distribution of the core, the balance between viscosity and mechanical properties can be optimized when the graft copolymer composition is dispersed in the curable resin.

[0056] According to an embodiment of the present invention, the condition of (3) is a distribution with respect to the content of large-sized core particles having a particle size of 350 nm or more and 550 nm or less in the core, and the core particles having a particle size of 350 nm or more and 550 nm or less may be 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 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, and may also be 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, 10 wt% or less, 9 wt% or less, 8 wt% or less, or 7 wt% or less. Thus, when a plurality of graft copolymers having different core particle sizes satisfy the condition of (3) in the particle size distribution of the core, the decrease in mechanical properties due to the region where the distance between particles increases and the graft copolymer composition is absent can be prevented when the graft copolymer composition is dispersed in the curable resin. Here, although the range of large-sized core particles is referred to as having a particle size of 350 nm or more and 550 nm or less, this is not intended to exclude large-sized core particles having a particle size exceeding 550 nm, and the particle size range is for indicating the particle size range of the large-sized core particles showing the maximum particle size among the core particles.

[0057] According to an embodiment of the present invention, the core may have an average particle size of 250 nm or more and 350 nm or less. As a specific example, the average particle size may be 250 nm or more, 260 nm or more, 270 nm or more, 280 nm or more, 290 nm or more, or 295 nm or more, and may also be 350 nm or less, 340 nm or less, 335 nm or less, 330 nm or less, 325 nm or less, 320 nm or less, 315 nm or less, 310 nm or less, 305 nm or less, or 300 nm or less. When the graft copolymer composition is dispersed in the curable resin within this range, by preventing the occurrence of aggregation between small particles, it is possible to prevent a decrease in dispersibility due to an increase in viscosity.

[0058] Thus, when adjusting the content of the core and the particle size distribution of the core in a plurality of graft copolymers having different core particle sizes included in the graft copolymer composition according to the present invention, the curable resin composition can be dispersed by the powder phase dispersion method.

[0059] According to an embodiment of the present invention, the plurality of graft copolymers may have an average particle size of 250 nm to 500 nm, 250 nm to 450 nm, or 250 nm to 400 nm. When the graft copolymer is dispersed in the curable resin within this range, an increase in viscosity can be prevented.

[0060] According to an embodiment of the present invention, for a specimen in which 8 parts by weight of the dispersion phase containing the graft copolymer composition is dispersed with respect to 100 parts by weight of the continuous phase containing the curable resin in the graft copolymer composition, the particle size distribution of the rubber particles observed when magnified 15,000 times using a transmission electron microscope may satisfy the following (4) to (6). At this time, the rubber particles may be derived from the core in the graft copolymer composition contained in the dispersion phase, and the particle size distribution of the rubber particles may be adjusted from the particle size distribution of the core in the graft copolymer composition contained in the dispersion phase. (4) The number percentage of rubber particles having a particle size of 30 nm or more and less than 100 nm is 0% or more and 5% or less, (5) 50% by number or more and 95% by number or less of rubber particles having a particle size of more than 100 nm and less than 350 nm, (6) 5% by number or more and 50% by number of rubber particles having a particle size of 350 nm or more and 550 nm or less

[0061] According to an embodiment of the present invention, the condition of (4) is a distribution with respect to the content of small-sized rubber particles having a particle size of 30 nm or more and less than 100 nm among the rubber particles. The rubber particles having a particle size of 30 nm or more and less than 100 nm may be 0% by number or more, 1% by number or more, 2% by number or more, or 3% by number or more, and may also be 5% by number or less, 4% by number or less, 3% by number or less, or 2% by number or less. This range relates to the appropriate number range of small-sized rubber particles among the dispersed rubber particles when the graft copolymer composition is dispersed in a continuous phase containing a curable resin. When the condition of (4) is satisfied in the particle size distribution of the rubber particles, there is an effect that the viscosity can be lowered by minimizing or eliminating the content of small-sized rubber particles in the curable resin composition. Here, although the range of small-sized rubber particles is referred to as having a particle size of 30 nm or more and less than 100 nm, this is not intended to exclude small-sized rubber particles having a particle size of less than 30 nm. The particle size range is for indicating the particle size range of the small-sized core particles showing the minimum particle size among the rubber particles.

[0062] According to one embodiment of the present invention, the condition of (5) is a distribution with respect to the content of medium-sized rubber particles having a particle size of 100 nm or more and less than 350 nm among the rubber particles, and the rubber particles having a particle size of 100 nm or more and less than 350 nm may be 50% by number or more, 55% by number or more, 60% by number or more, 65% by number or more, 70% by number or more, 75% by number or more, 80% by number or more, 85% by number or more, or 90% by number or more, and may also be 95% by number or less, 94% by number or less, 93% by number or less, 92% by number or less, 91% by number or less, 90% by number or less, 85% by number or less, 80% by number or less, 75% by number or less, 70% by number or less, or 65% by number or less. This range relates to an appropriate number range of medium-sized rubber particles among the dispersed rubber particles when the graft copolymer composition is dispersed in a continuous phase containing a curable resin. When the condition of (5) is satisfied in the particle size distribution of the rubber particles, the balance between the dispersion viscosity and the mechanical properties of the curable resin composition containing the graft copolymer composition in the dispersed phase can be optimized.

[0063] According to one embodiment of the present invention, the condition of (6) is a distribution with respect to the content of large-sized rubber particles having a particle size of 350 nm or more and 550 nm or less among the rubber particles, and the rubber particles having a particle size of 350 nm or more and 550 nm or less may be 5% by number or more, 6% by number or more, 7% by number or more, 8% by number or more, 9% by number or more, 10% by number or more, 15% by number or more, 20% by number or more, 25% by number or more, or 30% by number or more, and may also be 50% by number or less, 45% by number or less, 40% by number or less, 35% by number or less, 30% by number or less, 25% by number or less, 20% by number or less, 15% by number or less, 10% by number or less, 9% by number or less, 8% by number or less, 7% by number or less, or 6% by number or less. This range relates to an appropriate number range of large-sized rubber particles among the dispersed rubber particles when the graft copolymer composition is dispersed in a continuous phase containing a curable resin. When the condition of (6) is satisfied in the particle size distribution of the rubber particles, it is possible to prevent a decrease in mechanical properties due to an increase in the distance between the rubber particles dispersed in the curable resin composition containing the graft copolymer composition in the dispersed phase and a region where the graft copolymer composition is absent. Here, although the range of the large-sized rubber particles is referred to as having a particle size of 350 nm or more and 550 nm or less, this is not intended to exclude large-sized rubber particles having a particle size exceeding 550 nm, and the particle size range is for indicating the particle size range of the large-sized rubber particles showing the maximum particle size among the rubber particles.

[0064] According to one embodiment of the present invention, the curable resin may be a thermosetting resin or a photocurable resin. As specific examples, it may be one or more selected from the group consisting of epoxy resins, phenol resins, unsaturated polyester resins, melamine resins, and urea resins, and as a more specific example, it may be an epoxy resin.

[0065] According to an embodiment of the present invention, the epoxy resin may contain at least two or more epoxy bonds. Specific examples include 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, aliphatic cyclic epoxy resin, and glycidylamine type epoxy resin.

[0066] The present invention provides a method for producing the graft copolymer composition. The graft copolymer production method includes a step (S1) of producing a rubbery polymer latex containing a rubbery polymer whose particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation) satisfies the above (1) to (3); and a step of charging a graft monomer and performing graft polymerization in the presence of 75% by weight or more and 85% by weight or less (based on solid content) of the rubbery polymer latex to produce a graft copolymer latex containing a graft copolymer composition containing a plurality of core-shell shaped graft copolymers (S2).

[0067] According to an embodiment of the present invention, in the method for producing the graft copolymer composition, the types and contents of the monomers for carrying out each step may be the same as those of the monomers of the graft copolymer composition described above.

[0068] According to an embodiment of the present invention, the step (S1) is a step for producing a rubbery polymer that forms a core or a core layer in a core-shell shaped graft copolymer, and is characterized in that it is adjusted and produced so that the particle size distribution of the rubbery polymer particles measured by CHDF (Capillary Hydrodynamic Fractionation) satisfies the above (1) to (3). The step (S2) is a step for forming a shell or a shell layer in a shell shape that wraps the core by graft polymerization on the rubbery polymer.

[0069] According to an embodiment of the present invention, the steps (S1) and (S2) may be each carried out by emulsion polymerization, and may be carried out in the presence of electrolytes, molecular weight regulators, activators, etc., including the emulsifier and initiator introduced during emulsion polymerization. At this time, when carrying out the step (S1), the particle size distribution of the rubbery polymer particles may be adjusted by the input content of the emulsifier.

[0070] According to an embodiment of the present invention, the emulsifier may be one or more selected from the group consisting of fatty acid emulsifiers and rosin acid emulsifiers. In this case, there is an effect of excellent latex stability.

[0071] According to an embodiment of the present invention, the input content of the emulsifier in the step (S1) may be 0.1 part by weight to 3.4 parts by weight, 1.0 part by weight to 3.3 parts by weight, 1.5 part by weight to 3.2 parts by weight, 2.0 parts by weight to 3.2 parts by weight, or 2.1 parts by weight to 3.1 parts by weight with respect to 100 parts by weight of the monomer for polymerizing the rubbery polymer. Within this range, the particle size distribution of the rubbery polymer particles can be adjusted to satisfy the above (1) to (3).

[0072] According to an embodiment of the present invention, the input content of the emulsifier in the step (S2) may be 0.1 part by weight to 1.0 part by weight, 0.1 part by weight to 0.5 part by weight, or 0.1 part by weight to 0.3 part by weight with respect to 100 parts by weight of the total of the rubbery polymer and the monomer for polymerizing the graft copolymer. Within this range, there is an effect of excellent latex stability.

[0073] According to an embodiment of the present invention, the step (S1) may be carried out using a water-soluble initiator that can be used during emulsion polymerization, and the water-soluble initiator may be potassium persulfate, sodium persulfate, ammonium persulfate, etc. The step (S2) may be carried out by radical polymerization using a peroxide-based, redox, or azo-based initiator that can be used during emulsion polymerization. The redox initiator may, for example, be one or more selected from the group consisting of t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, and cumene hydroperoxide. In this case, there is an effect of providing a stable polymerization environment. When using the redox initiator, it may be further carried out by further including ferrous sulfide, sodium ethylenediaminetetraacetate, and sodium formaldehyde sulfoxylate as a redox catalyst which is an activator. By adjusting the input content of the redox initiator and the redox catalyst, the weight average molecular weight of the shell may be adjusted to 40,000 g / mol or less.

[0074] According to an embodiment of the present invention, the step (S2) may be carried out by continuously charging the graft monomer. When carrying out the step (S2), if the graft monomer is charged all at once before the start of the graft polymerization reaction, there may be a problem of an increase in the weight average molecular weight of the shell.

[0075] According to an embodiment of the present invention, the emulsion polymerization in the step (S1) and the step (S2) may be carried out in an aqueous solvent, and the aqueous solvent may be ion-exchanged water.

[0076] According to an embodiment of the present invention, the method for producing the graft copolymer composition may include a step (S3) of aggregating and drying to obtain the graft copolymer latex produced in the step (S2) in a powder phase.

[0077] The present invention provides a curable resin composition. The curable resin composition may include the graft copolymer composition as an impact reinforcing agent. As a specific example, the graft copolymer composition may be dispersed in a powder phase.

[0078] According to an embodiment of the present invention, the curable resin composition includes a continuous phase and a dispersed phase. The continuous phase includes a curable resin, and the dispersed phase may include the graft copolymer composition. As a specific example, the curable resin composition may include 50 wt% to 99 wt%, 50 wt% to 80 wt%, or 50 wt% to 70 wt% of the continuous phase; and 1 wt% to 50 wt%, 20 wt% to 50 wt%, or 30 wt% to 50 wt% of the dispersed phase.

[0079] According to an embodiment of the present invention, the curable resin may be a thermosetting resin or a photocurable resin. As a specific example, it may be one or more selected from the group consisting of epoxy resins, phenolic resins, unsaturated polyester resins, melamine resins, and urea resins. As a more specific example, it may be an epoxy resin.

[0080] According to an embodiment of the present invention, the epoxy resin may include at least two or more epoxy bonds. As a specific example, it 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, aliphatic cyclic epoxy resin, and glycidylamine type epoxy resin.

[0081] According to one embodiment of the present invention, in the cured resin composition, when observed under a transmission electron microscope at a magnification of 15,000 times with respect to a specimen in which 8 parts by weight of the dispersed phase is dispersed in 100 parts by weight of the continuous phase, the number of rubber particles may be 200 to 500. As a specific example, the number of the rubber particles may be 200 or more, 210 or more, 220 or more, 230 or more, 240 or more, 250 or more, 260 or more, 270 or more, 280 or more, 290 or more, 300 or more, 350 or more, 400 or more, or 450 or more, and may also be 500 or less, 490 or less, 480 or less, 470 or less, 460 or less, 450 or less, 400 or less, 350 or less, 300 or less, 290 or less, 280 or less, 270 or less, 260 or less, or 250 or less. This range relates to the appropriate range of rubber particles dispersed in the curable resin composition, and within this range, the distance between the rubber particles dispersed in the curable resin composition can be most effectively adjusted, so there are excellent effects on both the dispersion viscosity and mechanical properties.

[0082] According to one embodiment of the present invention, in the cured resin composition, when observed under a transmission electron microscope at a magnification of 15,000 times with respect to a specimen in which 8 parts by weight of the dispersed phase is dispersed in 100 parts by weight of the continuous phase, the particle size distribution of the rubber particles may satisfy the following (4) to (6). At this time, the rubber particles may be derived from the core in the graft copolymer composition contained in the dispersed phase, and the particle size distribution of the rubber particles may be adjusted from the particle size distribution of the core in the graft copolymer composition contained in the dispersed phase. (4) The number percentage of rubber particles having a particle size of 30 nm or more and less than 100 nm is 0% or more and 5% or less. (5) The number percentage of rubber particles having a particle size of 100 nm or more and less than 350 nm is 50% or more and 95% or less. (6) The number percentage of rubber particles having a particle size of 350 nm or more and 550 nm or less is 5% or more and 50%

[0083] According to one embodiment of the present invention, the condition of (4) is a distribution with respect to the content of small-sized rubber particles having a particle size of 30 nm or more and less than 100 nm among the rubber particles. The rubber particles having a particle size of 30 nm or more and less than 100 nm may be 0 number %, 1 number %, 2 number %, or 3 number % or more, and may also be 5 number % or less, 4 number % or less, 3 number % or less, or 2 number % or less. This range relates to the appropriate number range of small-sized rubber particles among the rubber particles dispersed in the curable resin composition. In the curable resin composition, when the condition of (4) is satisfied in the particle size distribution of the rubber particles, the content of the small-sized rubber particles in the curable resin composition is minimized or not contained, and thus there is an effect that the viscosity can be lowered. Here, although the range of the small-sized rubber particles is referred to as having a particle size of 30 nm or more and less than 100 nm, this is not intended to exclude small-sized rubber particles having a particle size of less than 30 nm. The particle size range is for indicating the particle size range of the small-sized core particles showing the minimum particle size among the rubber particles.

[0084] According to one embodiment of the present invention, the condition of (5) is a distribution with respect to the content of medium-sized rubber particles having a particle size of 100 nm or more and less than 350 nm among the rubber particles. The rubber particles having a particle size of 100 nm or more and less than 350 nm may be 50 number %, 55 number %, 60 number %, 65 number %, 70 number %, 75 number %, 80 number %, 85 number %, or 90 number % or more, and may also be 95 number % or less, 94 number % or less, 93 number % or less, 92 number % or less, 91 number % or less, 90 number % or less, 85 number % or less, 80 number % or less, 75 number % or less, 70 number % or less, or 65 number % or less. This range relates to the appropriate number range of medium-sized rubber particles among the rubber particles dispersed in the curable resin composition. In the curable resin composition, when the condition of (5) is satisfied in the particle size distribution of the rubber particles, the balance between the dispersion viscosity and the mechanical properties can be optimized.

[0085] According to an embodiment of the present invention, the condition of (6) is a distribution with respect to the content of large-sized rubber particles having a particle size of 350 nm or more and 550 nm or less among the rubber particles, and the rubber particles having a particle size of 350 nm or more and 550 nm or less may be 5% by number or more, 6% by number or more, 7% by number or more, 8% by number or more, 9% by number or more, 10% by number or more, 15% by number or more, 20% by number or more, 25% by number or more, or 30% by number or more, and may also be 50% by number or less, 45% by number or less, 40% by number or less, 35% by number or less, 30% by number or less, 25% by number or less, 20% by number or less, 15% by number or less, 10% by number or less, 9% by number or less, 8% by number or less, 7% by number or less, or 6% by number or less. This range relates to the appropriate number range of large-sized rubber particles among the rubber particles dispersed in the curable resin composition. In the curable resin composition, when the condition of (6) is satisfied in the particle size distribution of the rubber particles, the distance between the rubber particles dispersed in the curable resin composition increases, and it is possible to prevent a decrease in mechanical properties due to the region where the graft copolymer composition is absent. Here, although the range of the large-sized rubber particles is referred to as having a particle size of 350 nm or more and 550 nm or less, this is not intended to exclude large-sized rubber particles having a particle size exceeding 550 nm, and the particle size range is for indicating the particle size range of the large-sized rubber particles showing the maximum particle size among the rubber particles.

[0086] According to an embodiment of the present invention, in addition to the curable resin and the graft copolymer composition, the curable resin composition may further contain a curing agent. The curing agent may be one or more selected from the group consisting of an acid anhydride curing agent, an amine-based curing agent, and a phenol-based curing agent.

[0087] According to an embodiment of the present invention, the acid anhydride curing agent may be at least one selected from the group consisting of phthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methyl hymic anhydride, methylcyclohexene dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bistrimellitate, glycerol tristrimellitate, dodecenyl succinic anhydride, polyazelainic anhydride, and poly(ethyloctadecanedioic acid) anhydride.

[0088] According to an embodiment of the present invention, the amine curing agent may be one or more selected from the group consisting of 2,5(2,6)-bis(aminomethyl)bicyclo[2,2,1]heptane, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, bis(4-amino-3-methyldicyclohexyl)methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, diethyltoluenediamine, 3,3'-diaminodiphenylsulfone (3,3'-DDS), 4,4'-diaminodiphenylsulfone (4,4'-DDS), diaminodiphenylether (DADPE), bisaniline, benzyldimethylaniline, 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,3-tolylenediamine, 2,4-tolylenediamine, 2,5-tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine, methylthiotoluenediamine, diethyltoluenediamine, and dicyandiamide.

[0089] According to an embodiment of the present invention, the phenolic curing agent may be one or more selected from the group consisting of phenol novolak resin, cresol novolak resin, bisphenol A, bisphenol F, bisphenol AD, and derivatives of diallylated bisphenols.

[0090] According to an embodiment of the present invention, in addition to the curable resin and the graft copolymer composition, the curable resin composition may further contain an additive. The additive may be a mold release agent such as silicone oil, natural wax, and synthetic wax; a powder such as crystalline silica, fused silica, calcium silicate, and alumina; a fiber such as glass fiber and carbon fiber; a flame retardant such as antimony trioxide; a halogen trap agent such as hydrotalcite and rare earth oxide; a colorant such as carbon black and iron oxide; and a silane coupling agent, etc.

[0091] The present invention also provides a method for producing a curable resin composition for producing the curable resin composition.

[0092] According to an embodiment of the present invention, the method for producing the curable resin composition includes a step (S10) of preparing a graft copolymer latex containing the graft copolymer composition; a step (S20) of aggregating and drying the graft copolymer latex prepared in the step (S10) to produce a graft copolymer powder; and a step (S30) of mixing a curable resin and the graft copolymer powder produced in the step (S20) to produce a curable resin composition, and the step (S30) may be carried out by dispersion using a stirrer.

[0093] According to an embodiment of the present invention, the step (S10) is a step for producing the graft copolymer composition, and may be carried out by the method for producing the graft copolymer described above.

[0094] According to an embodiment of the present invention, the step (S20) is a step for obtaining the graft copolymer prepared in the step (S10) as a powder phase, and may be carried out by aggregating and drying the graft copolymer latex prepared in the step (S10).

[0095] According to an embodiment of the present invention, the aggregation in the step (S20) may be carried out by adding a flocculant to the graft copolymer latex. Further, the aggregation in the step (S20) may be carried out by acid aggregation such as an aqueous sulfuric acid solution or salt aggregation such as sodium chloride or sodium sulfate, and all of the acid aggregation and the salt aggregation may be carried out as necessary. At this time, the acid aggregation and the salt aggregation may be carried out simultaneously or stepwise. When the aggregation is carried out stepwise, the salt aggregation may be carried out after the acid aggregation, or the acid aggregation may be carried out after the salt aggregation. Further, the aggregation in the step (S20) may be carried out in the presence of an organic dispersant as necessary.

[0096] According to an embodiment of the present invention, the drying in the step (S20) may be carried out by a normal drying method, and may further include a step of dehydrating the aggregated graft copolymer latex prior to drying as necessary.

[0097] According to an embodiment of the present invention, in applying the graft copolymer as an impact reinforcing agent to the curable resin, the step (S30) is a step of mixing the curable resin and the graft copolymer by the powder phase dispersion method as described above, and it may be carried out by charging and mixing the graft copolymer powder into the curable resin. As described above, the graft copolymer according to the present invention has excellent powder dispersibility and can be directly dispersed in the powder phase of the curable resin. As a specific example, the viscosity of the curable resin composition produced in the step (S30) is 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, 1,590 Pa·s or less, 1,580 Pa·s or less, 1,570 Pa·s or less, 1,560 Pa·s or less, 1,550 Pa·s or less, 1,540 Pa·s or less, 1,530 Pa·s or less, 1,520 Pa·s or less, 1,510 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 at 25 °C, and 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, 1,200 Pa·s or more, 1,250 Pa·s or more, 1,300 Pa·s or more, 1,350 Pa·s or more, 1,400 Pa·s or more, 1,450 Pa·s or more, 1,500 Pa·s or more, or 1,550 Pa·s or more. Within this range, the viscosity of the graft copolymer powder is low and the dispersibility is excellent.

[0098] In addition, the present invention provides an adhesive composition containing the curable resin composition. The adhesive composition may contain the curable resin composition as a toughening agent. According to an embodiment of the present invention, the adhesive composition may contain, in addition to the toughening agent, a main agent, a urethane resin, a curing agent, a curing accelerator, a filler, etc. that can be used in adhesives.

[0099] Hereinafter, the embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0100] Examples and Comparative Examples [Example 1] <Production of Rubber Polymer Latex> Into a polymerization reactor (autoclave) substituted with nitrogen, based on a total of 100 parts by weight of 1,3-butadiene, 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, potassium carbonate (K 2 CO 3 ) 0.9 parts by weight, t-dodecyl mercaptan 0.3 parts by weight, potassium persulfate (K 2 S 2 O 8 ) 0.3 parts by weight were charged all at once, and polymerization was carried out at a reaction temperature of 70°C. Subsequently, when the polymerization conversion rate was 30% to 40%, 0.7 parts by weight of potassium oleate was charged all at once, and then 20 parts by weight of 1,3-butadiene was charged all at once, and polymerization was continued at a reaction temperature of 70°C. Subsequently, after reaching the point where the polymerization conversion rate was 60%, 20 parts by weight of 1,3-butadiene was charged all at once, the reaction temperature was raised to 80°C, and then polymerization was continued until the polymerization conversion rate reached 95%, at which point the reaction was terminated. The total time required for polymerization was 23 hours, the gel content of the obtained rubber polymer latex was 76%, and the average particle diameter of the rubber polymer particles was 301 nm.

[0101] At this time, the polymerization conversion rate was calculated as the ratio of the solid content weight of the obtained rubber polymer to the solid content weight of the monomer charged.

[0102] <Production of Graft Copolymer Latex> Into a sealed polymerization reactor substituted with nitrogen, 80 parts by weight of the produced rubbery polymer latex based on 100 total parts by weight of the contents of the rubbery polymer latex (on a solids basis), methyl methacrylate, n-butyl acrylate, and styrene were charged. 200 parts by weight of ion-exchanged water, 0.2 part by weight of potassium oleate, 0.036 part by weight of ferrous sulfide, 0.2 part by weight of sodium ethylenediaminetetraacetate, 0.2 part by weight of sodium formaldehyde sulfoxylate, and 0.4 part by weight of t-butyl hydroperoxide were charged all at once. Subsequently, 16 parts by weight of methyl methacrylate, 3 parts by weight of n-butyl acrylate, and 1 part by weight of styrene were continuously charged over 3 hours while the polymerization proceeded at a reaction temperature of 60°C for 4 hours to produce a graft copolymer latex. The final polymerization conversion rate was 98.3%, and the average particle diameter of the graft copolymer particles was 313 nm.

[0103] The polymerization conversion rate was calculated as the ratio of the solids weight of the obtained graft copolymer to the solids weight of the charged rubbery polymer and monomers.

[0104] <Production of graft copolymer powder> The produced graft copolymer latex was diluted with distilled water to 15% by weight on a solids basis and then placed in a coagulation tank, and the internal temperature of the coagulation tank was raised to 45°C. Thereafter, IR1076 was added as an antioxidant with respect to 100 parts by weight of the graft copolymer on a solids basis, and while stirring, an aqueous sulfuric acid solution was added to cause coagulation. After separating the graft copolymer from water, dehydration and drying were performed to produce a graft copolymer powder.

[0105] [Example 2] In Example 1, when producing the rubbery polymer latex, 1.0 part by weight of potassium rosinate was added instead of 1.4 parts by weight, and 0.4 part by weight of potassium oleate was added instead of 0.6 part by weight. The procedure was the same as in Example 1 except that 0.6 part by weight of potassium oleate was added instead of 0.7 part by weight when the polymerization conversion rate reached 30% - 40%. At this time, the average particle size of the produced rubbery polymer particles was 333 nm, and the average particle size of the graft copolymer particles was 340 nm.

[0106] [Example 3] In Example 1, when producing the rubbery polymer latex, 1.2 parts by weight of potassium rosinate was added instead of 1.4 parts by weight, and 0.5 part by weight of potassium oleate was added instead of 0.6 part by weight. The procedure was the same as in Example 1 except that 0.9 part by weight of potassium oleate was added instead of 0.7 part by weight when the polymerization conversion rate reached 30% - 40%. At this time, the average particle size of the produced rubbery polymer particles was 295 nm, and the average particle size of the graft copolymer particles was 308 nm.

[0107] [Comparative Example 1] In Example 1, when producing the rubbery polymer latex, the procedure was the same as in Example 1 except that 0.8 part by weight of potassium oleate was added instead of 0.7 part by weight when the polymerization conversion rate reached 30% - 40%. At this time, the average particle size of the produced rubbery polymer particles was 290 nm, and the average particle size of the graft copolymer particles was 300 nm.

[0108] [Comparative Example 2] In Example 1, when producing the rubbery polymer latex, 1.5 parts by weight of potassium rosinate was added instead of 1.4 parts by weight. The procedure was the same as in Example 1 except that 0.6 part by weight of potassium oleate was added instead of 0.7 part by weight when the polymerization conversion rate reached 30% - 40%. At this time, the average particle size of the produced rubbery polymer particles was 287 nm, and the average particle size of the graft copolymer particles was 299 nm.

[0109] [Comparative Example 3] In Example 1, when producing the graft copolymer latex, 70 parts by weight of the rubbery polymer latex was charged instead of 80 parts by weight based on solids content, 24 parts by weight of methyl methacrylate was charged instead of 16 parts by weight, 4 parts by weight of n-butyl acrylate was charged instead of 3 parts by weight, and 2 parts by weight of styrene was charged instead of 1 part by weight, and the same method as in Example 1 was carried out. At this time, the average particle diameter of the produced graft copolymer particles was 318 nm.

[0110] [Experimental Example] [Experimental Example 1] For the rubbery polymers and graft copolymers produced in Examples 1 to 3 and Comparative Examples 1 to 3, the average particle diameters of the core and graft copolymers and the particle size distribution of the core were measured by the following methods, and the content of each component and the charging method of the graft monomer during the production of the graft copolymer were shown in Tables 1 and 2 below.

[0111] * Average particle diameter (nm) of core and graft copolymer: The rubbery polymer latex and graft copolymer latex produced in Examples 1 to 3 and Comparative Examples 1 to 3 were each diluted with distilled water at a concentration of 200 ppm, and then measured by the dynamic light scattering (DLS) method according to ISO22412 using NICOMP380.

[0112] * Particle size distribution of core (wt%): After producing a sample by diluting 0.1 g of the rubbery polymer latex produced in Examples 1 to 3 and Comparative Examples 1 to 3 with 100 g of distilled water, the particle size distribution of the core was measured using a CHDF (Capillary Hydrodynamic Fractionation) analyzer (Model 4000 of Matec Applied Science). At this time, for the particle size distribution of the core, after injecting the sample into the inside of a fine capillary using a syringe, the particles in the latex were separated using the difference in the moving speed of the particles in the sample to measure the particle size distribution, and during the measurement, the internal temperature of the fine capillary was maintained at 35°C. For the measured particle size distribution, the degree of distribution was classified according to the following conditions (1) to (3). (1) Weight ratio of core particles having a particle size of more than 30 nm and less than 100 nm (2) Weight ratio of core particles having a particle size of 100 nm or more and less than 350 nm (3) Weight ratio of core particles having a particle size of 350 nm or more and 550 nm or less

[0113] [Table 1]

[0114] [Table 2]

[0115] As shown in Tables 1 and 2 above, it was confirmed that the graft copolymer compositions of Examples 1 to 3 produced according to the present invention were produced within the ranges limited by the present invention in terms of the content of the cores of the plurality of graft copolymers in the graft copolymer composition and the particle size distribution of the cores.

[0116] On the other hand, it was confirmed that in Comparative Examples 1 and 2, the particle size distribution of the cores of the plurality of graft copolymers in the graft copolymer composition deviated from the ranges limited by the present invention.

[0117] Also, it was confirmed that in Comparative Example 3, the core content was produced at a content lower than the range limited by the present invention.

[0118] [Experimental Example 2] Using the graft copolymer powders produced in Examples 1 to 3 and Comparative Examples 1 to 3 above, for a specimen in which 8 parts by weight of a dispersion phase containing a graft copolymer composition was dispersed in 100 parts by weight of a continuous phase containing a curable resin, in order to observe the number of rubber particles when magnified 15,000 times using a transmission electron microscope, a specimen was produced by the following method.

[0119] [Production of Specimen] 100 parts by weight of an epoxy resin (Kokoku Chemical Co., Ltd., YD-128), 8 parts by weight of the graft copolymer powder produced above, 10 parts by weight of a curing agent (Evonik Co., Ltd., Dicyanex 1400F), and 1 part by weight of a curing accelerator (Evonik Co., Ltd., Amicure UR7 / 10) were blended using a paste mixer (KMTECH Co., Ltd., PDM-300). The blended mixture was placed in an aluminum dish with a diameter of 5 cm and cured at 180°C for 5 minutes to produce a specimen with a diameter of 5 cm.

[0120] For the specimen produced above, it was magnified 15,000 times and photographed using a transmission electron microscope. The number of rubber particles and the particle size distribution of the rubber particles observed at this time were confirmed and shown in Tables 3 and 4 below. A transmission electron microscope image of the epoxy resin composition specimen in which the graft copolymer composition of Example 1 was dispersed is shown in Figure 3.

[0121]

Table 3

[0122]

Table 4

[0123] As shown in Tables 3 and 4 and Figure 3 above, it was confirmed that in the epoxy resin compositions containing the graft copolymer compositions of Examples 1 to 3 produced according to the present invention, the rubber particles derived from the core of the graft copolymer composition were evenly dispersed.

[0124] On the other hand, in Comparative Example 1 in which the proportion of small-sized core particles is high and the proportion of large-sized core particles is low and does not satisfy the core particle size distribution defined in the present invention, and in Comparative Example 2 in which the proportion of medium-sized core particles is high and the proportion of large-sized core particles is low and does not satisfy the core particle size distribution defined in the present invention, it was confirmed that the rubber particles were unevenly dispersed and the degree of dispersion was not uniform.

[0125] Also, even when including a core having the same particle size distribution as in Example 1, it was confirmed that Comparative Example 3 with a low core content showed a low number of rubber particles itself.

[0126] [Experimental Example 3] Using the graft copolymer powders produced in Examples 1 to 3 and Comparative Examples 1 to 3 above, an epoxy resin composition specimen in which the graft copolymer composition was dispersed in a curable resin composition was produced by the following method. For the epoxy resin compositions in which the graft copolymer compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were dispersed, the dispersion state of the graft copolymer was confirmed by the following method, and the viscosity was measured and shown in Tables 5 and 6 below.

[0127] <Production of Epoxy Resin Composition Specimen in which Graft Copolymer Composition was Dispersed> Into a planetary mixer (KMTECH, KPLM - 0.6) set at 70°C, based on a total of 100 parts by weight of the contents of the epoxy resin and the graft copolymer, 60 parts by weight of an epoxy resin (Kokoku Chemical Co., YD - 128) and 40 parts by weight of the graft copolymer powders produced in Examples 1 to 3 and Comparative Examples 1 to 3 were charged and stirred at 10 rpm for 1 hour, 80 rpm for 2 hours, and 60 rpm for 10 hours to disperse the graft copolymer powders in the epoxy resin to produce an epoxy resin composition in which the graft copolymer was dispersed.

[0128] Subsequently, for specimen production, 100 parts by weight of an epoxy resin (Kokoku Chemical Co., YD - 128), 25 parts by weight of the epoxy resin composition produced above, 10 parts by weight of a curing agent (Evonik, Dicyanex 1400F), and 1 part by weight of a curing accelerator (Evonik, Amicure UR7 / 10) were blended using a paste mixer (KMTECH, PDM - 300). The blended mixture was placed in an aluminum dish with a diameter of 5 cm and cured at 180°C for 5 minutes to produce a specimen with a diameter of 5 cm.

[0129] *Dispersion state: An epoxy resin composition was applied to a cold-rolled (CR) steel sheet measuring 25 mm x 100 mm to a thickness of 0.2 mm, and the number of particles observable with the naked eye was confirmed. At this time, the lower the number of particles observable with the naked eye, the better the dispersion state.

[0130] *Viscosity at 25°C (Pa·s): For the produced epoxy resin composition, the viscosity at 25°C was measured using a Rheometer (Antonpaar, MRC302), and the viscosity values at shear rates of 2.4 s -1 and 100 s were shown.

[0131] [Table 5]

[0132] [Table 6]

[0133] As shown in Tables 5 and 6 above, it was confirmed that the curable resin composition in which the graft copolymer of the present invention was applied to the powder phase as an impact reinforcing agent had a sufficient dispersion state of the graft copolymer powder, and of course, had a low viscosity at 25°C and excellent dispersibility.

[0134] On the other hand, Comparative Example 1, in which the proportion of small-sized core particles was high and the proportion of large-sized core particles was low and did not satisfy the core particle size distribution defined in the present invention, was confirmed to have a deteriorated dispersion state and an increased viscosity. Comparative Example 2, in which the proportion of medium-sized core particles was high and the proportion of large-sized core particles was low and did not satisfy the core particle size distribution defined in the present invention, was confirmed to not have sufficient improvement in viscosity. Also, even when including a core having the same particle size distribution as in Example 1, Comparative Example 3, in which the core content was low, was shown to have a very high viscosity and poor dispersibility.

[0135] [Experimental Example 4] Using the epoxy resin composition produced in the above Experimental Example 3, a structural adhesive composition was produced by the following method.

[0136] <Production of Structural Adhesive Composition> As the main agent, an epoxy resin (Kokoku Chemical Co., Ltd., YD-128), as toughening agents, the epoxy resin compositions according to each of Examples 1 to 3 and Comparative Examples 1 to 3 produced in the above Experimental Example 2 (weight ratio of epoxy resin: graft copolymer powder = 60:40), a urethane resin (Adeka Co., Ltd., QR-9466), a diluent (Kokoku Fine Chemical Co., Ltd., KF EPIOL DE208), a curing agent (Evonik Co., Ltd., Dicyanex 1400F), a curing accelerator (Evonik Co., Ltd., Amicure UR7 / 10), calcium oxide (Yuyong Materials Co., Ltd., UNI-OX), and fumed silica (Cabot Co., Ltd., CAB-O-SIL TS-720) were mixed using a paste mixer (KMTECH Co., Ltd., PDM-300) at 600 rpm for revolution and 500 rpm for rotation for 3 minutes, and then defoamed at 600 rpm for revolution and 200 rpm for rotation for 5 minutes to produce an adhesive composition. At this time, the content of each component was charged based on 100 parts by weight of the total content of the main agent, toughening agent, urethane resin, and diluent.

[0137] For the produced structural adhesive composition, the impact peel strength was measured by the following method and shown in Tables 7 and 8 below.

[0138] * Impact peel strength (N / mm): The impact peel strength of the manufactured structural adhesive composition was measured according to ISO 11343. The size of the test piece was 90 mm X 20 mm X 1.6T (mm), and the size of one side where the adhesive composition was applied was 30 mm X 20 mm. After removing contaminants from one side of the test piece using ethanol, the manufactured structural adhesive composition was applied. The thickness of the adhesive composition was kept constant using microbeads, and after covering and fixing another test piece thereon, it was cured at 180 °C for 30 minutes. After curing, it was stabilized at 25 °C and -40 °C for 1 hour or more, and then a load was applied at a speed of 2 m / sec using an impact strength tester (Instron, 9350), and the impact peel strength based on shear strength was measured.

[0139]

Table 7

[0140]

Table 8

[0141] As shown in Tables 7 and 8 above, when the curable resin composition of the present invention was applied as a toughening agent to the adhesive composition, it was confirmed that the impact peel strength of the structural adhesive composition was excellent at both normal temperature (25 °C) and low temperature (-40 °C).

[0142] From such results, it was confirmed that the graft copolymer epoxy resin of the present invention has excellent powder dispersibility with respect to curable resins such as curable resin compositions, and can be dispersed by a powder phase dispersion method, so that the productivity of the curable resin composition is excellent, and the mechanical properties such as impact resistance can be improved by the graft copolymer dispersed in the curable resin composition.

Claims

1. Comprising a plurality of graft copolymers having different core particle sizes, The graft copolymer is a core-shell graft copolymer comprising a core containing a rubbery polymer; and a shell formed by graft polymerization of a graft monomer containing an alkyl (meth)acrylate monomer on the rubbery polymer, The plurality of graft copolymers contain 75% by weight or more and 90% by weight or less of the core, After staining a specimen in which 8 parts by weight of a dispersion phase containing a graft copolymer composition is dispersed with respect to 100 parts by weight of a continuous phase containing an epoxy resin, when magnified 15,000 times using a transmission electron microscope, the number of rubber particles observed in an image of 12 μm in width and 8 μm in length is 200 or more and 500 or less of the graft copolymer composition.

2. The graft copolymer composition according to claim 1, wherein the core satisfies the following (1) to (3) in the particle size distribution measured by CHDF (Capillary Hydrodynamic Fractionation): (1) 0% by weight or more and 4% by weight or less of core particles having a particle size of 30 nm or more and less than 100 nm, (2) 50% by weight or more and 94% by weight or less of core particles having a particle size of 100 nm or more and less than 350 nm, (3) 6% by weight or more and 50% by weight or less of core particles having a particle size of 350 nm or more and 550 nm or less.

3. The graft copolymer composition according to claim 1, wherein the rubbery polymer contains one or more monomer units selected from the group consisting of conjugated diene monomer units and alkyl acrylate monomer units.

4. The graft copolymer composition according to claim 1, wherein the graft monomer contains a methyl (meth)acrylate monomer, an alkyl (meth)acrylate monomer having 2 to 12 carbon atoms, and a crosslinkable monomer.

5. The graft copolymer composition according to claim 4, wherein the crosslinkable monomer is polyethylene glycol diacrylate or allyl methacrylate.

6. The graft copolymer composition according to claim 1, wherein the graft monomer further contains an aromatic vinyl monomer.

7. The graft copolymer composition according to claim 1, wherein the plurality of graft copolymers contain 75% by weight or more and 85% by weight or less of the core and 15% by weight or more and 25% by weight or less of the shell.

8. The graft copolymer composition according to claim 1, wherein the average particle size of the core of the plurality of graft copolymers is 250 nm or more and 350 nm or less.

9. When the graft copolymer composition is observed at a magnification of 15,000 times using a transmission electron microscope for a specimen in which 8 parts by weight of a dispersion phase containing the graft copolymer composition is dispersed in 100 parts by weight of a continuous phase containing an epoxy resin, the particle size distribution of rubber particles observed in an image having a horizontal dimension of 12 μm and a vertical dimension of 8 μm satisfies the following (4) to (6). The graft copolymer composition according to claim 1: (4) 0 to 5% by number of rubber particles having a particle size of 30 nm or more and less than 100 nm, (5) 50 to 95% by number of rubber particles having a particle size of 100 nm or more and less than 350 nm, (6) 5 to 50% by number of rubber particles having a particle size of 350 nm or more and 550 nm or less.

10. Comprising a continuous phase and a dispersion phase, The continuous phase contains an epoxy resin, The dispersion phase is an epoxy resin composition containing the graft copolymer composition according to any one of claims 1 to 9.

11. The epoxy resin composition according to claim 10, comprising 50 to 99% by weight of a continuous phase and 1 to 50% by weight of a dispersion phase.

12. Preparing a graft copolymer latex containing the graft copolymer composition according to any one of claims 1 to 9 (step S10); Aggregating and drying the graft copolymer latex prepared in the step (S10) to produce a graft copolymer powder (step S20); Mixing an epoxy resin and the graft copolymer powder produced in the step (S20) to produce an epoxy resin composition (step S30), and The step (S30) is a method for producing an epoxy resin composition carried out by dispersion using a stirrer.

13. The viscosity of the epoxy resin composition produced in the step (S30) is 2,000 Pa·s or less at 25°C. The method for producing an epoxy resin composition according to claim 12.

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