Resin composition comprising epoxy resin and method for producing same

Abstract

Provided is an epoxy resin composition that imparts excellent impact resistance. Provided is a method for producing an epoxy resin composition, comprising: (1) a step for melting or softening an impact modifier in a kneader; (2) a step for supplying an epoxy resin to the kneader; and (3) a step for dispersing the impact modifier in the epoxy resin in the kneader to obtain an impact modifier / epoxy resin mixture. (4) The method preferably further comprises a step for supplying an epoxy resin to the kneader to dilute the impact modifier / epoxy resin mixture.

Description

Resin composition containing epoxy resin and method for producing the same

[0001] The present invention relates to a resin composition containing an epoxy resin and a method for producing the same.

[0002] Cured epoxy resins exhibit excellent properties in many respects, including dimensional stability, mechanical strength, electrical insulation, heat resistance, water resistance, and chemical resistance. However, cured epoxy resins can have low fracture toughness and exhibit very brittle properties, which often poses problems in a wide range of applications.

[0003] One conventional method to solve these problems is to blend rubber components into epoxy resins. Among these methods, a method of blending pre-prepared rubber polymer particles using polymerization methods in an aqueous medium, such as emulsion polymerization, dispersion polymerization, and suspension polymerization, has several advantages compared to methods such as dissolving and mixing a non-crosslinked rubber component with epoxy resin and then causing phase separation during the curing process to generate a dispersed phase of rubber components in the continuous phase of the cured epoxy resin. These advantages include, in principle, less variation in the dispersion state due to blending and curing conditions, and less reduction in heat resistance and rigidity because the rubber component is pre-crosslinked, preventing contamination of the continuous phase of the cured epoxy resin with rubber components. For these reasons, various manufacturing methods, as shown below, have been proposed.

[0004] Patent Document 1 (Japanese Patent Publication No. 5-295237) discloses a method of crushing a solidified rubbery polymer latex and then mixing it with an epoxy resin. In this method, the rubbery polymer is separated from water by being temporarily removed as a solid, but the handling of this solid and the mixing process with the epoxy resin are complicated and industrially undesirable. Furthermore, when the rubbery polymer is temporarily removed as a solid and then mixed and redispersed with the epoxy resin, it is difficult to redisperse the rubbery polymer particles in the epoxy resin as primary particles, even if considerable mechanical shear force is used for crushing and dispersion operations.

[0005] Patent document 2 (Japanese Patent Publication No. 6-107910) discloses a method for obtaining a mixture by mixing a rubbery polymer latex and an epoxy resin, and then removing the water by distillation. In this method, since the epoxy resin and water do not mix well, dried material is generated in the unmixed areas, forming lumps that will negatively affect the quality unless removed. Furthermore, a large amount of water must be removed in the presence of the epoxy resin, which makes the operation difficult.

[0006] Patent document 3 (U.S. Patent No. 4,778,851) discloses a method for obtaining a mixture by mixing a rubbery polymer latex with an epoxy resin in the presence of an organic solvent. In this method, when mixing the rubbery polymer latex and the epoxy resin, it is necessary to separate or distill off a large amount of water (more water than the amount of water that the organic solvent can dissolve) that is present in the system (mixture) along with the organic solvent. However, separating the organic solvent layer from the water layer requires a considerable amount of time, such as 24 hours, or the organic solvent layer and the water layer form a stable emulsified suspension state, making separation practically impossible. Furthermore, if water is distilled off, a large amount of energy is required, and water-soluble impurities such as emulsifiers and auxiliary materials usually used in the production of rubbery polymer latex remain in the composition, resulting in inferior quality. For these reasons, the removal of water by either separation or distillation is complicated and industrially undesirable.

[0007] Patent Document 4 (WO2004 / 108825) discloses a method for producing an epoxy resin composition in which rubbery polymer particles (B) are stably dispersed and mixed in a epoxy resin (A). This method involves contacting an aqueous latex of rubbery polymer particles (B) with an organic medium (C) that is partially soluble in water, and then contacting it with an organic medium (D) that is less partially soluble in water than (C) to substantially separate the aqueous layer from the rubbery polymer particles (B). The resulting dispersion (F) consisting of the rubbery polymer particles (B) and the mixed organic mediums (C) and (D) is then mixed with an epoxy resin (A), and volatile components are removed to obtain a modified epoxy resin composition simply and efficiently. However, the process is complicated due to the multiple steps involved and can only be applied to specific aqueous latexes.

[0008] Patent document 5 (WO2018 / 131570) discloses a method of mixing 13 μm fine particles of ethylene-glycidyl methacrylate copolymer, which have been pre-ground, into epoxy resin using a batch mixer, without melting the copolymer, while maintaining its original particle size. However, there are challenges, such as the need to pre-ground the particles and the difficulty in further reducing the dispersion particle size while maintaining productivity.

[0009] JP-A-5-295237 JP-A-6-107910 U.S. Patent No. 4,778,851 WO2004 / 108825 WO2018 / 131570

[0010] The object of the present invention is to provide an epoxy resin composition that provides excellent impact resistance.

[0011] The present invention relates to a method for producing an epoxy resin composition by dispersing an impact modifier in a liquid epoxy resin using a kneader.

[0012] Aspects of the present invention are as follows: [1] A method for producing an epoxy resin composition, comprising the steps of: (1) melting or softening an impact modifier in a kneader; (2) supplying an epoxy resin in a kneader; and (3) dispersing the impact modifier in an epoxy resin in a kneader to obtain an impact modifier / epoxy resin mixture. [2] The method according to [1], further comprising the step of: (4) supplying an epoxy resin in a kneader to dilute the impact modifier / epoxy resin mixture. [3] The method according to [1] to [2], further comprising the step of: (5) degassing by suction using a vacuum vent in a kneader. [4] The method according to [1] to [3], further comprising the step of: (6) cooling the epoxy resin in which the impact modifier has been dispersed, obtained from the kneader, by passing it through a heat exchanger. [5] The method according to [1] to [4], wherein the kneader is a continuous kneader. [6] The manufacturing method according to [1] to [5], wherein in step (1), the impact improving material is heated to a temperature of 100°C or higher in order to melt or soften the impact improving material. [7] The manufacturing method according to [1] to [6], wherein in step (2), the epoxy resin is in liquid form. [8] The manufacturing method according to [1] to [7], wherein in step (3), the kneading zone of the kneader is composed of a damming section and a kneading section, and the damming section generates a pressure of 0.1 MPa or higher on its upstream side. [9] The manufacturing method according to [1] to [8], wherein the epoxy resin is a prepolymer having epoxy groups.

[10] The manufacturing method according to [1] to [9], wherein the epoxy equivalent of the epoxy resin is 50 to 10,000 g / eq as measured according to JIS K7236, and the viscosity of the epoxy resin is 1,000 mPa·s to 50,000 mPa·s as measured using a Brookfield viscometer at 25°C and 10 rpm.

[11] The dissolution parameter (SP value) of the impact modifier is 9 (cal / cm³). ３ ) １／２ ~13(cal / cm ３ ) １／２The manufacturing method according to [1] to

[10] , wherein the impact improving material is at least one selected from ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl acrylate copolymer, ethylene / butyl acrylate copolymer / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene propylene copolymer elastomer (EPR), ethylene butene copolymer elastomer (EBR), ethylene hexene copolymer elastomer (EHR), ethylene octene copolymer elastomer (EOR), ethylene propylene diene copolymer elastomer (EPDM), acrylic rubber, and styrene-based elastomer. The manufacturing method according to [1] to

[11] .

[13] The manufacturing method according to [1] to

[12] , wherein the weight ratio of epoxy resin to impact modifier in the resin composition is 30:70 to 99:1.

[0013] The epoxy resin composition of the present invention has a small dispersion average particle size, thus providing a cured epoxy resin product with excellent impact resistance.

[0014] This is a schematic diagram illustrating one aspect of the manufacturing method of the present invention, including an outline of a continuous kneading machine.

[0015] Steps (1) to (4) are carried out in a kneader, in particular a continuous kneader. The kneader may be single-screw or multi-screw (especially two-screw). The kneader has a cylinder and a screw housed inside the cylinder. The screw has flights (blades). The materials to be kneaded (epoxy resin and thermoplastic impact modifier) ​​are kneaded as they pass through the clearance (gap) between the flights and the cylinder, and in the case of multi-screw kneaders, through the clearance (gap) between the flights.

[0016] <Step (1)> In Step (1) (the first step), after supplying the thermoplastic impact modifier, the thermoplastic impact modifier is heated to melt or soften it. Although melting or softening the thermoplastic impact modifier can be done by various methods, it is preferable to place a kneading segment such as a forward disc upstream of a segment that has the effect of blocking the molten or softened resin, such as a neutral disc, reverse disc, reverse flight, or seal ring. At this time, it is preferable that the pressure immediately in front of the segment that has the effect of blocking is 0.1 MPa or higher. The heating temperature is the temperature at which melting or softening occurs, and is preferably, for example, 100°C or higher, 120 to 250°C, or 150 to 200°C.

[0017] In step (1), a solvent (organic solvent) may be used. It is preferable to add the solvent after adding the impact modifier to the kneader. Alternatively, a solution of the impact modifier may be added to the kneader. That is, a solution of the impact modifier obtained by dissolving the impact modifier in a solvent may be used. By using a solvent, the particles of the impact modifier in the dispersion can be made smaller. The solvent (organic solvent) is preferably a hydrocarbon (aromatic hydrocarbon, aliphatic hydrocarbon). Specific examples of solvents include xylene and cyclohexane. It is preferable that the solvent is removed in the kneader. Solvent removal can be performed by vacuum venting or the like.

[0018] <Process (2)> In process (2) (the second process), epoxy resin (liquid epoxy resin) is supplied to the kneader. The epoxy resin can be supplied to the kneader quantitatively via a liquid addition nozzle, etc., using a gear pump, deforming pump, rotary lobe pump, etc. The screw shape of the second process is not particularly specified, but if pressure is generated (the pressure becomes (significantly) higher than atmospheric pressure), the quantitative accuracy of liquid addition will be impaired, so a shape that does not generate pressure (does not generate high pressure) is preferable. A feed flight is a preferred example.

[0019] <Step (3)> Step (3) (the third step) is a step in which the impact modifier melted in the first step and the liquid epoxy resin supplied to the kneader (continuous kneader) in the second step are dispersed and mixed. In step (3), a mixture of impact modifier and epoxy resin (impact modifier / epoxy resin mixture) is obtained. The impact modifier / epoxy resin mixture is a dispersion in which the impact modifier is dispersed in the epoxy resin. The impact modifier / epoxy resin mixture has a sea-island structure in which the continuous phase is epoxy resin and the dispersed phase is impact modifier.

[0020] The third step is preferably carried out in the mixing zone of the mixing machine. The mixing zone of the mixing machine consists of a damming section and a mixing section. The mixing zone has a mixing section upstream and a damming section downstream. The mixing section disperses and mixes the impact modifier and epoxy resin.

[0021] The damming section preferably generates a pressure (gauge pressure) of 0.01 MPa or more, 0.05 MPa or more, 0.1 MPa or more, 0.2 MPa or more, 0.3 MPa or more, 0.5 MPa or more, or 1 MPa or more on its upstream side. In this specification, the generated pressure (gauge pressure) can be detected by a pressure gauge installed on the cylinder. The damming section is preferably formed by one, two, or three reverse flights. The clearance between the flights and the cylinder is preferably 3% or less, 2% or less, or 1% or less of the cylinder diameter D, and the lead length is preferably 1D or less or 0.5D or less.

[0022] In the kneading section (the kneading zone upstream of the damming section), a combination of screw segments commonly used as kneading segments, such as forward kneading discs (KD), reverse kneading discs, neutral kneading discs, and rotors, can be used. In addition, single-fly and double-fly configurations can also be used. A screw configuration that generates a pressure of 0.05 MPa or higher, 0.1 MPa or higher, 0.2 MPa or higher, 0.3 MPa or higher, or 0.5 MPa or higher upstream of the 1D from the boundary with the damming section (for example, the boundary between the kneading zone and the downstream zone (for example, the dilution zone)) is preferred.

[0023] To make the particle size of the impact-improving material small and uniform, it is preferable to use one or two flight lines in the mixing zone. When using one or two flight lines in the mixing zone, it is especially preferable to generate a pressure of 0.05 MPa or more, 0.1 MPa or more, 0.2 MPa or more, 0.3 MPa or more, or 0.5 MPa or more on the 1D upstream side from the boundary with the damming section. In the mixing zone, the number of damming sections and mixing sections may be two or more.

[0024] <Step (4)> Step (4) is an optional step that may be omitted. In step (4) (the fourth step), epoxy resin is again supplied to the kneader in the same manner as in the second step, and the impact modifier already dispersed in the epoxy resin in the kneading zone is diluted (dilution zone). Since epoxy resin has a lower viscosity than impact modifier, it is difficult to reduce the particle size of the dispersed impact modifier if the amount of epoxy resin is large. Therefore, it is preferable to supply the epoxy resin in two parts, in the second and fourth steps. Furthermore, by adding unheated epoxy resin to the molten impact modifier, the temperature of the impact modifier / epoxy resin mixture can be quickly lowered.

[0025] Before the fourth step (third step), the weight ratio of epoxy resin to impact modifier may be 30:70 to 99:1, 40:60 to 98:2, 60:40 to 95:5, or 80:20 to 90:10. After the fourth step, the weight ratio of epoxy resin to impact modifier may be 20:80 to 99:1, 30:70 to 99:1, 40:60 to 98:2, 60:40 to 95:5, or 80:20 to 90:10.

[0026] <Additional steps> Additional steps may be used as needed.

[0027] In step (5) (the fifth step), degassing by suction using a vacuum vent is preferable. Step (5) is preferably carried out in a kneader. This makes it possible to remove volatile components such as water and organic solvents.

[0028] In step (6) (the sixth step), it is preferable to quickly lower the temperature of the epoxy resin containing the impact-improving material obtained from the kneader by passing it through a heat exchanger or the like.

[0029] The resulting epoxy resin composition can also be stored in a tank.

[0030] Figure 1 is a schematic diagram illustrating one aspect of the manufacturing method of the present invention, including an outline of a continuous kneader. The continuous kneader has a first region 11, a second region 12, a third region 13, a fourth region 14, and a fifth region 15. In the first step (first region 11), a thermoplastic impact modifier is supplied and then heated to melt or soften it. In the second step (second region 12), liquid epoxy resin is supplied to the kneader. In the third step (third region 13), the molten impact modifier and epoxy resin are mixed to obtain a dispersion in which particles of the impact modifier are dispersed in the epoxy resin. In the fourth step (fourth region 14), epoxy resin is further supplied to the kneader. By adding epoxy resin, which is the dispersion medium, the impact modifier dispersed in the epoxy resin is diluted. In this way, a resin composition, which is a dispersion, is obtained. In the fifth step (fifth region 15), degassing is performed by suction using a vacuum vent. Furthermore, the temperature of the resin composition is lowered by passing the dispersion through a heat exchanger. Next, the resin composition is sent to a tank (storage tank).

[0031] The materials used in this invention are described below. <Epoxy resin>

[0032] The epoxy resin is preferably a prepolymer having epoxy groups. The epoxy resin may also be an epoxy resin known as a polyepoxide. The epoxy resin is preferably having two or more epoxy groups in one molecule.

[0033] Examples of the epoxy resin include glycerol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexanedimethanol type epoxy resin, cyclic aliphatic glycidyl ether, epoxy resin having a butadiene structure, dicyclopentadiene type epoxy resin, epoxy resin containing an alkyleneoxy skeleton, and epoxy resin containing a fluorene structure, etc. [[ID=,2]]

[0034] The epoxy resin is preferably, for example, diglycidyl ether of bisphenol A, novolac type epoxy resin, trifunctional or tetrafunctional epoxy resin, furthermore, a high molecular weight epoxy resin (for example, diglycidyl ether of bisphenol A having a high molecular weight with bisphenol A, etc.), or also a homopolymer or copolymer obtained by polymerizing an unsaturated monoepoxide (for example, glycidyl (meth)acrylate, allyl glycidyl ether).

[0035] Examples of the polyepoxide used in the present invention include glycidyl ethers of polyhydric alcohols and polyhydric phenols, polyglycidyl amines, polyglycidyl amides, polyglycidyl imides, polyglycidyl hydantoins, polyglycidyl thioethers, epoxidized fatty acids or epoxidized drying oils, epoxidized polyolefins, epoxidized unsaturated polyesters, and mixtures thereof. The polyepoxide is synthesized from monohydric, dihydric, and trihydric phenols and includes novolac resins. The polyepoxide includes, in addition to epoxidized cycloolefins, polyepoxides obtained from polymers and copolymers of glycidyl (meth)acrylate and allyl glycidyl ether.

[0036] The epoxy resin may be one kind or a combination of two or more kinds.

[0037] Polyepoxides generally preferably have an epoxy equivalent weight of 80 to 2000 or 200 to 1000. Polyepoxides can be obtained by well-known methods. Usually, a commonly used method is, for example, reacting an excess amount of epihalohydrin with a polyhydric alcohol or polyhydric phenol in the presence of a base.

[0038] The epoxy equivalent weight of the epoxy resin is preferably 50 to 10,000 g / eq, 100 to 5,000 g / eq or 150 to 3,000 g / eq as measured by JIS K7236.

[0039] The polyepoxides used in the present invention may contain a monoepoxide as a reactive diluent, for example, an aliphatic glycidyl ether such as butyl glycidyl ether, phenyl glycidyl ether or cresyl glycidyl ether. As is generally known, monoepoxides affect the stoichiometry of polyepoxide formulations, and the adjustment thereof is carried out by the amount of the curing agent or other well-known methods.

[0040] The epoxy resin is liquid at a temperature of 25°C. The viscosity of the epoxy resin may be 1000 mPa·s to 50000 mPa·s, 1500 mPa·s to 20000 mPa·s, or 2000 mPa·s to 10000 mPa·s. The viscosity can be measured using a Brookfield viscometer under the conditions of 25°C and 10 rpm.

[0041] <Impact modifier> The thermoplastic impact modifier is a polymer that imparts elasticity to the resin composition. The thermoplastic impact modifier is preferably an elastomer or rubber. The elastic modulus of the impact modifier is preferably 10 to 1000 MPa, 100 to 500 MPa, or 300 to 400 MPa. The elastic modulus (flexural elastic modulus) can be measured according to JIS K7113:1995. Alternatively, the elastic modulus is preferably 300 MPa or less or 100 MPa or less, for example, 0.1 to 50 MPa.

[0042] In the present invention, the impact-improving material (rubber polymer) generally contains a polymer whose glass transition temperature is lower than room temperature, and in which some of the molecules are constrained by each other through covalent bonds, ionic bonds, van der Waals forces, entanglement, etc.

[0043] Examples of impact-improving materials (rubber polymers) include polybutadiene, polyisoprene, random and block copolymers of styrene-butadiene, hydrogenated block copolymers, diene rubbers such as acrylonitrile-butadiene copolymer and butadiene-isoprene copolymer, random and block copolymers of ethylene-propylene, random and block copolymers of ethylene-butene, copolymers of ethylene and α-olefin, ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid and ethylene-methacrylic acid, ethylene-unsaturated carboxylic acid ester copolymers such as ethylene-acrylic acid ester and ethylene-methacrylic acid ester, and a portion of the unsaturated carboxylic acid is a metal salt. Some preferred examples include ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid metal salt copolymers such as ethylene-acrylic acid-acrylic acid metal salt and ethylene-methacrylic acid-methacrylic acid metal salt, acrylic ester-butadiene copolymers such as butyl acrylate-butadiene copolymer, copolymers of ethylene and fatty acid vinyl such as ethylene-vinyl acetate, ethylene-propylene-ethylene-propylene unconjugated diene ternary copolymers such as ethylene-propylene-ethylidene norbornene copolymer and ethylene-propylene-hexadiene copolymer, butylene-isoprene copolymer, chlorinated polyethylene, polyamide elastomers, and thermoplastic elastomers such as polyester elastomers.

[0044] Specific examples of impact-improving materials that are rubber components (elastomers) include ethylene propylene copolymer elastomer (EPR), ethylene butene copolymer elastomer (EBR), ethylene hexene copolymer elastomer (EHR), ethylene octene copolymer elastomer (EOR), ethylene propylene diene copolymer elastomer (EPDM), and styrene-based elastomers such as styrene butadiene styrene copolymer elastomer (SBS), styrene isoprene styrene copolymer elastomer (SIS), styrene ethylene propylene styrene copolymer elastomer (SEPS), and hydrogenated styrene butadiene styrene block elastomer (SEBS).

[0045] The impact-reducing material may be acrylic rubber. Acrylic rubber is a polymer containing 60% by weight or more, preferably 80% by weight or more, and more preferably 90% by weight or more, of (meth)acrylic acid ester monomer units as polymer monomer units in its molecule.

[0046] Examples of (meth)acrylic acid ester monomers include alkyl (meth)acrylic acid ester monomers and alkoxyalkyl (meth)acrylic acid ester monomers.

[0047] Preferred alkyl (meth)acrylate monomers are esters of an alkanol having 1 to 8 carbon atoms and (meth)acrylic acid, including methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isopropyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and cyclohexyl (meth)acrylate. Among these, ethyl (meth)acrylate and n-butyl (meth)acrylate are preferred.

[0048] As the (meth)acrylate alkoxyalkyl ester monomer, esters of an alkoxy alkanol having 2 to 8 carbon atoms and (meth)acrylic acid are preferred, including methoxymethyl (meth)acrylate, ethoxymethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-propoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, and 4-methoxybutyl (meth)acrylate. Among these, 2-ethoxyethyl (meth)acrylate and 2-methoxyethyl (meth)acrylate are preferred.

[0049] Other examples of impact modifiers include styrene-based elastomers, such as ethylene / ethyl acrylate-g-methyl methacrylate / butyl acrylate copolymer, ethylene / ethyl acrylate-g-methyl methacrylate copolymer, ethylene / ethyl acrylate-g-maleic anhydride copolymer, ethylene / methyl methacrylate-g-maleic anhydride copolymer, ethylene / ethyl acrylate-g-maleimide copolymer, ethylene / propylene-g-maleic anhydride copolymer, and ethylene / butene-1-g-maleic anhydride copolymer.

[0050] The impact modifier is preferably a copolymer of ethylene and (another monomer). Examples of copolymers of ethylene and (another monomer) include ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl acrylate copolymer, ethylene / butyl acrylate copolymer / glycidyl methacrylate copolymer, and ethylene / vinyl acetate / glycidyl methacrylate copolymer.

[0051] The impact modifier is preferably an ethylene / glycidyl methacrylate copolymer, an ethylene / methyl acrylate / glycidyl methacrylate copolymer, an ethylene / ethyl acrylate / glycidyl copolymer, an ethylene / butyl acrylate copolymer / glycidyl methacrylate copolymer, or an ethylene / vinyl acetate / glycidyl methacrylate copolymer.

[0052] The impact modifier may be one kind, or a combination of two or more kinds.

[0053] The solubility parameter (SP value) (unit: (cal / cm ３ )) １／２ of the impact modifier is preferably 9 to 13 (or 9 to 12), 9.5 to 12, or 10 to 11. With such solubility parameters, the dispersed particle size in the epoxy resin can be reduced. The solubility parameter is a physical property value defined by the square root of the cohesive energy density and can be calculated from the following formula. <00,00123>

[0054] Solubility parameter (SP value) = [(δ ｄ ) 2 +(δ ｐ ) 2 +(δ ｈ ) 2 1 / 2

[0055] δ ｄ : dispersion term, δ ｐ [[ID=--33]]: polar term, δ ｈ : hydrogen bond term

[0056] The glass transition temperature of the impact modifier is -10°C or lower, for example, preferably -10°C to -100°C. The glass transition temperature can be measured according to JIS K7121-1987.

[0057] The average particle size of resin particles such as rubber particles (particles of the impact modifier) is preferably 1.0 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.3 μm or less. And the average particle size is preferably 0.03 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.08 μm or more. When the average particle size is 1.0 μm or less, the physical properties (for example, impact resistance) of the resin composition are improved.

[0058] ​The resin composition is a dispersion in which impact-improving particles are dispersed in epoxy resin (liquid epoxy resin).

[0059] In the final resin composition, the weight ratio of epoxy resin to impact modifier may be 20:80 to 99:1, 30:70 to 99:1, 40:60 to 98:2, 60:40 to 95:5, or 80:20 to 90:10. In the third step, the concentration of the impact modifier may be higher than that of the resin composition. In the third step (after the second step), the weight ratio of epoxy resin to impact modifier may be 30:70 to 99:1, 40:60 to 98:2, 60:40 to 95:5, or 80:20 to 90:10.

[0060] The average particle size of the impact-improving material particles in the resin composition may be 12 μm or less, 10 μm or less, 5 μm or less, 4 μm or less, or 3 μm or less, and may be 0.3 μm or more, 0.5 μm or more, or 1 μm or more. Preferably, the average particle size is 1 to 4 μm or 2 to 3 μm. The average particle size can be measured by dynamic light scattering (DLS) (or static light scattering).

[0061] <Other Components> The resin composition may contain other components. These other components are, for example, additives. Examples of additives include antioxidants, lubricants, ultraviolet absorbers, heat stabilizers, antistatic agents, polymerization inhibitors, defoamers, solvents, anti-aging agents, radical inhibitors, adhesion modifiers, flame retardants, surfactants, storage stability modifiers, ozone aging inhibitors, thickeners, plasticizers, radiation shielding agents, coupling agents, conductivity modifiers, phosphorus-based peroxide decomposers, pigments, metal deactivators, and property modifiers. These additives may be used individually or in combination of two or more. The amount of additives may be 30% by weight or less, 0.1 to 20% by weight, or 1 to 10% by weight relative to the resin composition.

[0062] In this specification, the symbol "~" indicating a numerical range generally includes the lower and upper numerical limits indicated before and after the symbol "~", but may not include one or both of the lower and upper numerical limits. That is, "1~10" generally means "1 or more and 10 or less", but may also mean "greater than 1 and 10 or less", "1 or more and less than 10", or "greater than 1 and less than 10".

[0063] Next, the present invention will be specifically described with reference to examples, comparative examples, and test examples. However, these descriptions are not intended to limit the present invention. In the following, parts, percentages, or ratios refer to parts by weight, weight percentages, or weight ratios, unless otherwise specified.

[0064] The equipment, materials, and test methods used in the following are as follows:

[0065] Continuous kneader: Co-rotating twin-screw extruder TEM-26SX (manufactured by Shibaura Machine Co., Ltd.), cylinder bore: 26.6 mm

[0066] Epoxy resin: Mitsubishi Chemical Industries JER828 (Bisphenol A type epoxy resin, epoxy equivalent weight 184-194 g / eq, viscosity 12,000-15,000 mPa·s)

[0067] Impact-reducing material: BondFirst® CG5001 manufactured by Sumitomo Chemical (GMA concentration 19%, MFR 380g / 10min)

[0068] [Measurement of Dispersed Particle Size] The particle size distribution of the diluent is measured using a HORIBA Partica la-950v2 (laser diffraction / scattering type), and the values ​​of D50 and Dmax are read.

[0069] Example 1 A resin composition was manufactured using a continuous kneader schematicly shown in Figure 1. The kneader's rotation speed was set to 400 rpm, the first step was set to 200°C, and the impact-improving material was supplied at 5 kg / h and melted. In the second step, epoxy resin was supplied at 5 kg / h, and in the third step, one reverse flight with a clearance between the flight and cylinder of 0.66% of the cylinder diameter D and a lead length of 0.25D was used in the damming section, and one flight was used in the kneading section, generating a pressure of 0.6 MPa 1D upstream of the boundary to obtain resin composition 1.

[0070] Example 2 A resin composition was produced using a continuous kneader schematicly shown in Figure 1. The kneader's rotation speed was set to 400 rpm, the first step was set to 200°C, and the impact-improving material was supplied at 5 kg / h and melted. In the second step, epoxy resin was supplied at 10 kg / h, and in the third step, one reverse flight with a clearance between the flight and cylinder of 0.66% of the cylinder diameter D and a lead length of 0.25D was used in the damming section, and one flight was used in the kneading section, generating a pressure of 0.2 MPa 1D upstream of the boundary to obtain resin composition 2.

[0071] Example 3 A resin composition was manufactured using a continuous kneader schematicly shown in Figure 1. The kneader was set to rotate at 600 rpm, the first step was set to 200°C, and the impact modifier was supplied at 5 kg / h and melted. In the second step, epoxy resin was supplied at 10 kg / h. In the third step, one reverse flight with a clearance between the flight and cylinder of 0.66% of the cylinder diameter D and a lead length of 0.25D was used in the damming section, and one flight was used in the kneading section to generate a pressure of 0.8 MPa 1D upstream of the boundary. In the fourth step, epoxy resin was supplied at 5 kg / h to obtain resin composition 3.

[0072] Example 4 A resin composition was manufactured using a continuous kneader schematicly shown in Figure 1. The kneader's rotation speed was set to 1200 rpm, the first step was set to 200°C, and the impact-improving material was supplied at 5 kg / h and melted. In the second step, epoxy resin was supplied at 5 kg / h. In the third step, one reverse flight with a clearance between the flight and cylinder of 0.66% of the cylinder diameter D and a lead length of 0.25D was used in the damming section, and one flight was used in the kneading section to generate a pressure of 0.7 MPa 1D upstream of the boundary. In the fourth step, epoxy resin was supplied at 10 kg / h to obtain resin composition 4.

[0073] Example 5 A resin composition was manufactured using a continuous kneader schematicly shown in Figure 1. The kneader was set to rotate at 800 rpm, the first step was set to 200°C, and the impact-improving material was supplied at 5 kg / h and melted. In the second step, epoxy resin was supplied at 5 kg / h. In the third step, one reverse flight with a clearance between the flight and cylinder of 0.66% of the cylinder diameter D and a lead length of 0.25D was used in the damming section, and one flight was used in the kneading section to generate a pressure of 1.4 MPa upstream of the boundary 1D. In the fourth step, epoxy resin was supplied at 115 kg / h to obtain resin composition 5.

[0074] The resin composition of the present invention can be used as an adhesive and structural material, among other components, in various fields such as sporting goods, automobiles, pressure tanks, aircraft, and tensioning materials.

[0075] 10 Continuous kneader 11 First area 12 Second area 13 Third area 14 Fourth area 15 Fifth area 20 Heat exchanger 30 Tank

Claims

1. A method for producing an epoxy resin composition, comprising: (1) a step of melting or softening an impact modifier in a kneader; (2) a step of supplying an epoxy resin in a kneader; and (3) a step of dispersing the impact modifier in the epoxy resin in a kneader to obtain an impact modifier / epoxy resin mixture.

2. (4) The manufacturing method according to claim 1, further comprising the step of supplying epoxy resin in a kneader and diluting the impact modifier / epoxy resin mixture.

3. (5) The manufacturing method according to claim 1, further comprising a step of degassing by suction using a vacuum vent in a kneading machine.

4. (6) The manufacturing method according to claim 1, further comprising the step of passing the epoxy resin in which the impact-improving material obtained from the kneader is dispersed through a heat exchanger to cool it.

5. The manufacturing method according to claim 1, wherein the kneader is a continuous kneader.

6. The manufacturing method according to claim 1, wherein in step (1), the impact-improving material is heated to a temperature of 100°C or higher in order to melt or soften the impact-improving material.

7. The manufacturing method according to claim 1, wherein the epoxy resin is in liquid form in step (2).

8. The manufacturing method according to claim 1, wherein in step (3), the kneading zone of the kneader is composed of a damming section and a kneading section, and the damming section generates a pressure of 0.1 MPa or more on its upstream side.

9. The manufacturing method according to claim 1, wherein the epoxy resin is a prepolymer having epoxy groups.

10. The manufacturing method according to claim 1, wherein the epoxy equivalent of the epoxy resin is 50 to 10,000 g / eq as measured according to JIS K7236, and the viscosity of the epoxy resin is 1,000 mPa·s to 50,000 mPa·s as measured using a Brookfield viscometer at 25°C and 10 rpm.

11. The dissolution parameter (SP value) of the impact-improving material is 9 (cal / cm²). ３ ) １／２ ~13(cal / cm ３ ) １／２ The manufacturing method according to claim 1.

12. The manufacturing method according to claim 1, wherein the impact-improving material is at least one selected from ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, ethylene / methacrylic acid copolymer, ethylene / glycidyl methacrylate copolymer, ethylene / methyl acrylate / glycidyl methacrylate copolymer, ethylene / ethyl acrylate / glycidyl acrylate copolymer, ethylene / butyl acrylate copolymer / glycidyl methacrylate copolymer, ethylene / vinyl acetate / glycidyl methacrylate copolymer, ethylene propylene copolymer elastomer (EPR), ethylene butene copolymer elastomer (EBR), ethylene hexene copolymer elastomer (EHR), ethylene octene copolymer elastomer (EOR), ethylene propylene diene copolymer elastomer (EPDM), acrylic rubber, and styrene-based elastomer.

13. The manufacturing method according to claim 1, wherein the weight ratio of epoxy resin to impact modifier in the resin composition is 30:70 to 99:1.

Images