JP2015232111A - Polyfunctional acid anhydride, thermosetting resin composition using the same, and cured product of the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition that gives a cured product excellent in heat resistance, toughness, coloring resistance, and dimensional stability, and in particular a resin composition having characteristics suitable for optical components.SOLUTION: A polyfunctional acid anhydride is obtained by reaction of a polyhydric alcohol (A), which is obtained by reaction of tris(2-hydroxyethyl)isocyanurate with one or more compounds selected from the group consisting of alkylene oxides, cyclic ethers, and cyclic esters, with a nucleus-hydrogenated trimellitic acid anhydride halide or a mixture of a nucleus-hydrogenated trimellitic acid anhydride halide (b-1) and a trimellitic acid anhydride halide (b-2). A thermosetting resin composition comprises the polyfunctional acid anhydride and a compound (B) containing at least one epoxy group in one molecule.

Description

  The present invention relates to a polyfunctional acid anhydride, a curable resin composition containing the polyfunctional acid anhydride, and a cured product thereof. The hardened | cured material of invention has the characteristic excellent in heat resistance, toughness, coloring resistance, and dimensional stability.

  A curable resin composition containing an epoxy resin is used as a resin having excellent heat resistance in the fields of architecture, civil engineering, automobiles, aircraft, and the like. In the field of semiconductor-related materials, epoxy resins used for electronic devices have been required to have very high characteristics, and in recent years, their use in optoelectronics-related fields has attracted attention.

Display devices such as a liquid crystal display, a plasma display, an EL display, and a portable device are widely used by general consumers, and demands for display on a curved surface and stereoscopic display are increasing as the size, weight, and thickness of the display device are increased. In order to satisfy various requirements such as transparency, hardness, chemical resistance, and gas barrier properties, glass plates are widely used for optical elements such as display elements and front panels of such apparatuses. However, there is a problem that the glass plate is easily broken and heavy, and in order to solve this problem, a plastic material such as an epoxy resin has been studied as an alternative to the glass plate, and various proposals have been made.

  For example, Patent Document 1 describes a transparent resin substrate for a liquid crystal display element using an epoxy resin, an acid anhydride curing agent, and alcohol. Patent Document 2 and Patent Document 3 describe a transparent substrate using a glass cloth and a thermosetting resin, and Patent Document 4 describes a resin sheet using a resin-cured layer containing a glass fiber cloth and inorganic particles. Has been.

  Glass substitute plastic materials such as these are prone to warp and crack due to shrinkage during curing in the production process, and it is difficult to obtain a smooth sheet. In addition, even during its use, the coefficient of linear expansion is larger than that of the glass plate, so problems may occur due to expansion and contraction during use, and color, heat resistance, color resistance, hardness, etc. Sufficient performance as required in the market as an alternative product has not been obtained.

In general, the epoxy resin curing agent used in such a field includes acid anhydride compounds. In particular, acid anhydrides formed with saturated hydrocarbons are often used because the cured product has excellent light resistance. As this acid anhydride, Patent Document 5 exemplifies a polyfunctional acid anhydride having an isocyanurate structure.
Cured products obtained using this acid anhydride are fragile, exhibiting excellent properties in transparency and heat resistance, especially in the form of sheets and films obtained by compounding with glass cloth. In order to obtain a product, problems such as cracking of the cured product and generation of dust when cutting the cured product have occurred.

JP-A-6-337408 JP 2004-233851 A JP 2004-269727 A JP 2005-156840 A JP 2012-025670 A

  An object of the present invention is to obtain a polyfunctional acid anhydride that gives a cured product excellent in toughness, heat resistance, transparency, and color resistance, and a thermosetting resin composition containing the polyfunctional acid anhydride. To do.

  The inventors of the present invention have developed a compound obtained by reacting an alcohol having three hydroxyl groups centered on an isocyanurate skeleton with a nuclear hydrogenated trimellitic anhydride halide while maintaining higher optical properties while maintaining toughness and heat resistance. The present inventors have found that a cured product having coloration resistance and further having dimensional stability can be obtained by adding fibers and particles.

  That is, the present invention provides (1) a polyhydric alcohol (a) obtained by reacting tris (2-hydroxyethyl) isocyanurate with one or more selected from the group consisting of alkylene oxide, cyclic ether, and cyclic ester. , Nuclear hydrogenated trimellitic anhydride halide (b-1) or a polyfunctional acid obtained by reacting a mixture of nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2) It relates to the anhydride (A).

(2) It relates to a thermosetting composition comprising the polyfunctional acid anhydride (A) and a compound (B) having at least one epoxy group in one molecule. (3) The present invention relates to the thermosetting resin composition further comprising particles (C-1) or fibers (C-2). (4) It is related with the said thermosetting resin composition whose said particle | grain (C-1) is an inorganic particle. (5) It is related with the said thermosetting resin composition whose said fiber (C-2) is glass fiber. (6) It is related with the said thermosetting resin composition whose said fiber (C-2) is a glass cloth.

(7) The thermosetting resin composition is provided with a shape in a semi-cured state. (8) The present invention relates to a cured product obtained by curing the thermosetting resin composition.

  The thermosetting resin composition containing the polyfunctional acid anhydride of the present invention has good stability, and the cured product is excellent in transparency, heat resistance, strength, smoothness, and light resistance. Paints and FRPs, and electrical and electronic materials such as paints, resist inks, adhesives, sealants and sealants in the field of printed wiring boards and semiconductors, and LED sealants and light that require high transparency It is suitable for a display device such as a waveguide, a liquid crystal display, a plasma display, an EL display, and a portable device, a solar battery, and the like.

  The polyhydric alcohol (a) used in the present invention reacts with one or more selected from the group consisting of tris (2-hydroxyethyl) isocyanurate and a reaction product of alkylene oxide, cyclic ether, and cyclic ester. Can be obtained. The polyhydric alcohol (a) can optimize the reactivity and properties of the cured product depending on the application.

  The alkylene oxide used in the present invention refers to a compound having a three-membered cyclic ether.

  As for carbon number of alkylene oxide, 2-8 are preferable. Examples thereof include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide. These alkylene oxides may be one kind or a mixture of two or more kinds as required. Among these, at least one selected from ethylene oxide and propylene oxide is preferable in the present invention because it is easily available and inexpensive.

  The cyclic ether used in the present invention is not particularly limited as long as it is a compound having a structure in which one or more carbons of a cyclic hydrocarbon having 4 or more members are substituted with oxygen.

  The cyclic ether is preferably a 4- to 6-membered ring, and specific examples include oxetane, tetrahydrofuran, and tetrahydropyran. These cyclic ethers may be one kind or a mixture of two or more kinds as necessary. Of these, tetrahydrofuran is preferred in the present invention because it is readily available and inexpensive.

  The cyclic ester used in the present invention is not particularly limited as long as it is a compound having a structure containing an ester bond in a cyclic hydrocarbon.

  It is preferable that carbon number of cyclic ester is 2-6. Specific examples of the cyclic ester include acetolactone, propiolactone, butyrolactone, valerolactone, caprolactone and the like. These cyclic esters may be one kind or a mixture of two or more kinds as required. Of these, caprolactone is preferred in the present invention because it is readily available and inexpensive.

  The amount of alkylene oxide, cyclic ether and cyclic ester used is 0.5 to 6.0 equivalents of alkylene oxide, cyclic ether and cyclic ester with respect to 1 equivalent of hydroxyl group of tris (2-hydroxyethyl) isocyanurate, 0.8 to 2.0 equivalents. Within this range, the resulting cured product has good heat resistance and toughness.

When the polyhydric alcohol (a) is produced by reacting tris (2-hydroxyethyl) isocyanurate with alkylene oxide, cyclic ether, or cyclic ester, the reaction temperature is 80 ° C to 250 ° C, preferably 90 ° C to 220 ° C. ° C, more preferably 100 ° C to 200 ° C. The reaction time is not particularly limited, but is usually 10 minutes to 48 hours, preferably 30 minutes to 24 hours. The reaction is usually carried out at normal pressure, but can be carried out under pressure or under reduced pressure as necessary.
In particular, in the case of a compound that gasifies near room temperature, such as ethylene oxide and propylene oxide, the reaction is preferably carried out in a pressure resistant vessel.

  The nuclear hydrogenated trimellitic anhydride halide (b-1) (cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride halide) used in the present invention is an acid anhydride group in a polyhydric alcohol. Introduced and used to make polyfunctional acid anhydride compounds. Due to the nuclear hydrogenation, there is little coloring even under heat and light resistance, and the cured product has excellent toughness while maintaining high optical properties.

  The trimellitic anhydride halide (b-2) (1,2,4-benzenetricarboxylic acid-1,2-anhydride halide) used in the present invention is used for the same purpose as the trimellitic anhydride halide. . Thereby, an acid anhydride group can be introduced without ring-opening esterification of the acid anhydride group. In addition, it has excellent heat resistance due to its rigid skeleton derived from aromatics.

  Examples of the nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2) include fluorinated products, chlorinated products, brominated products, and iodinated products, and among them, the ease of reaction is particularly preferred. To chlorinated products are preferred.

  When a mixture of nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2) is used in the present invention, b-1: b-2 = 100: 0 to 30:70, preferably 100: 0 to 40:60. The reaction ratio of the hydroxyl group of the polyhydric alcohol (a) or (d) to the nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2) is approximately the nuclear hydrogenated trimellitic anhydride. It corresponds to the molar ratio of acid halide (b-1) and trimellitic anhydride halide (b-2).

  The synthesis of the polyfunctional acid anhydride of the present invention can be performed by a known method in the presence of a basic substance. Polyhydric alcohol (a) and nuclear hydrogenated trimellitic anhydride halide (b-1) or a mixture of nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2) (hereinafter “ There are no particular restrictions on the method of adding each compound in the reaction with halides)), and any addition method can be employed. For example, a method in which a polyhydric alcohol (a) and a basic substance are dissolved in a solvent and the halides dissolved in the solvent are slowly added dropwise thereto, or conversely in the halides dissolved in the solvent as necessary. A method of dropping a mixed solution of a polyhydric alcohol (a) and a basic substance into a solution, a method of dropping a basic substance into a mixed solution of a halide and a polyhydric alcohol (a), and a polyhydric alcohol (a ), A solution of halides and a solution of a basic substance can be dropped simultaneously.

  In the reaction of the polyhydric alcohol (a) and halides in the presence of a basic substance, a hydrochloride formed by neutralization of the basic substance is generated as the reaction proceeds. After removing the hydrochloride by filtration, the filtrate is concentrated to obtain a crude product of the polyfunctional acid anhydride of the present invention in a high yield. This is dissolved in a suitable solvent, washed with water, concentrated and dried under reduced pressure to obtain a polyfunctional acid anhydride having a high purity. Furthermore, a polyfunctional acid anhydride with higher purity can be obtained by performing recrystallization with an appropriate solvent as necessary.

  The amount of polyhydric alcohol (a) used is usually the hydroxyl equivalent, when the hydroxyl equivalent of the halides (sum of the hydroxyl equivalent in the case of a mixture of trimellitic anhydride halide (b-2)) is 1.0. 0.6 to 1.0, preferably 0.8 to 1.0. Within this range, the hydroxyl groups of the polyhydric alcohol (a) are all esterified, and halides do not remain in the system.

  The solvent that can be used in the reaction between the halide and the polyhydric alcohol (a) is not particularly limited as long as it is inert to the raw material, but tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane-bis (2- Ether solvents such as methoxyethyl) ether, aromatic amine solvents such as picoline and pyridine, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbon solvents such as toluene and xylene, dichloromethane and chloroform Halogen-containing solvents such as 1,2-dichloroethane, amide solvents such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, Phosphorus-containing solvents such as hexamethylphosphoramide, dimethylsulfur Sulfur-containing solvents such as oxide, ester solvents such as γ-butyrolactone, ethyl acetate, butyl acetate, nitrogen-containing solvents such as 1,3-dimethyl-2-imidazolidinone, phenol, o-cresol , M-cresol, p-cresol, o-chlorophenol, m-chlorophenol, aromatic solvents having a hydroxyl group such as p-chlorophenol, and the like. These solvents may be used alone or in combination of two or more.

  When the halide is reacted with the polyhydric alcohol (a), the reaction temperature is -10 ° C to 80 ° C, preferably 0 ° C to 70 ° C, more preferably 10 ° C to 60 ° C. The solvents mentioned here contain cyclic ethers and cyclic esters. However, when the reaction temperature is higher than 80 ° C., the cyclic ether or cyclic ester further reacts with the polyhydric alcohol (a) to produce a polyhydric alcohol ( The reaction rate between a) and halides decreases. The reaction time is not particularly limited, but is usually 10 minutes to 48 hours, preferably 30 minutes to 24 hours. The reaction is usually carried out at normal pressure, but can be carried out under pressure or under reduced pressure as necessary.

  The concentration of the solute in the solvent in the reaction for obtaining the polyfunctional acid anhydride is usually 5% by mass to 50% by mass, preferably 10% by mass to 40% by mass in consideration of side reaction control and precipitation filtration step. In this reaction, the solute is more preferably in the range of 10% by mass to 40% by mass in the solvent.

  Usually, the reaction atmosphere is performed under nitrogen. The reaction vessel may be a closed type reaction vessel or an open type reaction vessel, but in order to keep the reaction system in an inert atmosphere, an open type vessel that can be sealed with an inert gas is used.

  The basic substance is used to neutralize hydrogen chloride generated as the reaction proceeds. The type of basic substance used at this time is not particularly limited, but organic basic amines such as pyridine, triethylamine and N, N-dimethylaniline, and inorganic basic substances such as potassium carbonate and sodium hydroxide are used. be able to. Pyridine and triethylamine are preferable in that they can be obtained at low cost and are easy to operate because they are liquid and highly soluble. Moreover, an inorganic basic substance is preferable in that it can be obtained at low cost.

  The amount of the basic substance to be used is not particularly limited, but if it is used excessively, it will be mixed into the product or the purification load will increase, so the number of moles of halides (trimellitic anhydride halide (b-2 In the case of a mixture of), the sum of the number of moles) is 1.0, and is usually 1.0 to 30 moles, preferably 1.2 to 20 moles, more preferably 1 .5 mole times to 10 mole times are used.

  During the water washing operation, the polyfunctional acid anhydride is partially hydrolyzed to be converted into a polycarboxylic acid. However, the polyfunctional acid can be easily converted into a polycarboxylic acid by heat treatment under reduced pressure. It can be returned to the anhydride. The temperature of the heat treatment under reduced pressure is 80 ° C. to 200 ° C., preferably 100 ° C. to 180 ° C., the degree of reduced pressure is 50 KPa or less, preferably 10 KPa or less, and the upper limit of the heating time is not particularly limited. Usually, it is 10 minutes to 48 hours, preferably 30 minutes to 24 hours.

  The polyfunctional acid anhydride of the present invention thus obtained can be further purified. As a purification method in that case, recrystallization, sublimation, washing, activated carbon treatment, column chromatography and the like can be arbitrarily performed. These purification methods can be repeated or combined. The purity of the polyfunctional acid anhydride of the present invention thus obtained is usually 90% or more, preferably 95% or more as an area ratio of peaks obtained by analysis such as gel permeation chromatography (hereinafter referred to as “GPC”). More preferably, it is 98% or more.

  The polyfunctional acid anhydride is preferably stored at a low temperature avoiding high humidity in order to prevent the acid anhydride ring from opening due to hydrolysis. Specifically, it can withstand long-term storage if stored in a refrigerator in a container with good sealing properties. Further, the polyfunctional acid anhydride may be used in the next polymerization reaction immediately after purification in order to prevent moisture absorption. The storage period at that time is usually within 100 hours, preferably within 50 hours, and more preferably within 24 hours.

  A thermosetting resin composition can also be constituted by combining the polyfunctional acid anhydride of the present invention with a compound that undergoes a curing reaction. At this time, there is no particular limitation as long as it is a compound having a functional group capable of reacting with an acid anhydride group by heat, but a compound having an epoxy group is particularly preferably used.

  At this time, in order to obtain a suitable thermosetting composition, it is preferable to use a compound in which at least two functional groups capable of reacting with an acid anhydride group are contained in one molecule.

  As the compound having an epoxy group shown in the present invention, any compound having at least one epoxy group in one molecule may be used. Hereinafter, an aromatic epoxy resin and an aliphatic epoxy resin will be described as a compound having at least one epoxy group in one molecule preferably used in the present invention.

  Aromatic epoxy resins include cresol novolac epoxy resins, phenol novolac epoxy resins, biphenyl-phenol epoxy resins, naphthol epoxy resins and other novolac epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, Bisphenol type epoxy resin such as bisphenol S type epoxy resin, trisphenolmethane type epoxy resin, glyoxal type epoxy resin, (4 (4 (1,1-bis (p-hydroxyphenyl) -ethyl) α, α-dimethylbenzyl) Phenol) type epoxy resin and the like. Among these, in the present invention, in consideration of heat resistance and color resistance, bisphenol A type epoxy resin, (4 (4 (1,1-bis (p-hydroxyphenyl) -ethyl) α, α-dimethylbenzyl) Phenol) type epoxy resin is preferred.

  Examples of the aliphatic epoxy resin include an epoxy resin having an aliphatic cyclic structure and an epoxy resin having no aliphatic cyclic structure. The epoxy resin having an aliphatic side cyclic structure has at least one cyclic aliphatic structure in one molecule. For example, polycondensation of terpene diphenol and phenols (phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and aliphatic ring structure dienes (dicyclopentadiene, norbornadiene, hexahydroxyindene, etc.) And glycidyl etherified products derived from these products and modified products thereof, hydrogenated bisphenol (bisphenol A, bisphenol F) type epoxy resins, alicyclic epoxy resins, etc., epoxy resins having a cyclohexyl structure in the molecule, dicyclopentadiene structures And epoxy resin having a triglycidyl isocyanurate structure. Specifically, for example, 1,2-cyclohexanediol diglycidyl ether, 3,4-epoxycyclohexenylmethyl-3 ′, 4′-epoxycyclohexenecarboxylate, 1,2-bis (hydroxyalkyl) -1-butanol Examples include epoxy-4- (2-oxiranyl) cyclohexane adducts.

  Examples of the compound having at least one epoxy group in one molecule having no aliphatic cyclic structure include glycidyl ethers derived from linear or branched alcohols such as hexanediglycidyl ether.

  In order to improve the properties of the thermosetting composition, for example, to impart strength, dimensional stability, toughness, or optical properties, it is also widely used in combination with particles, fibers and the like. However, the toughness of the resin becomes more important in making this composite. When the toughness of the resin is insufficient, the interface between the cured resin, the particles, and the fibers is broken, and the problem is easy cracking of the cured product and reduction in flexibility due to peeling. In general, if a flexible component is used for the resin in order to prevent this, the heat resistance and mechanical strength are lowered. Since the cured product using the polyfunctional acid anhydride of the present invention does not lose toughness while maintaining high heat resistance, it is suitable for a composition combined with particles and fibers. In the present invention, the particles and fibers are preferably incompatible with the polyfunctional acid anhydride (A) of the present invention and the compound (B) having at least one epoxy group in one molecule.

  The particles (C-1) used in the resin composition of the present invention include, for example, polymethyl methacrylate, polystyrene, nylon and the like as organic particles, and talc, fired clay, unfired clay as inorganic particles, Silicas such as mica and glass, oxides such as titanium oxide, alumina, silica and fused silica, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, aluminum hydroxide, magnesium hydroxide and calcium hydroxide Sulphate or sulfite such as hydroxide, barium sulfate, calcium sulfate and calcium sulfite, zinc borate, barium metaborate, borate such as aluminum borate, calcium borate and sodium borate, aluminum nitride, boron nitride And nitrides such as silicon nitride, magnesium fluoride, fluorine Can be mentioned fluoride such as calcium, it can be used to obtain from the market as a colloidal solution prepared by dispersing a fine powder and solvent free dispersion solvent. Moreover, these can be used 1 type or in mixture of 2 or more types. Dispersion solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and dimethyldimethylacetamide, esters such as ethyl acetate and butyl acetate, nonpolar solvents such as toluene and xylene, etc., each of the thermosetting resin composition of the present invention. What dissolves the components may be selected and used. In addition, inorganic particles are preferable from the viewpoint of dimensional stability. In particular, alumina and silica are preferable in view of versatility and low cost.

  The fiber (C-2) used in the resin composition of the present invention is carbon fiber, glass fiber, casein fiber, peanut protein fiber, corn protein fiber, soy protein fiber, algin fiber, chitin fiber, mannan fiber, rubber fiber, cellulose. Examples thereof include fibers, nylon fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyester fibers, polyacrylonitrile fibers, modacrylic fibers, polyethylene fibers, polypropylene fibers, polystyrene fibers, polyether ester fibers, polyurethane fibers and the like. These can be used alone or in combination of two or more. Among these, glass fiber is preferable from the viewpoint of versatility. In addition, there are various types of glass fibers such as woven fabrics, nonwoven fabrics, and knitted fabrics, and there is no particular limitation on the type in the present invention, but when impregnated with the thermosetting resin composition of the present invention and cured. In order to obtain a cured product having excellent dimensional stability, glass cloth is suitable. In consideration of adhesion to the thermosetting resin composition of the present invention, the glass fiber is preferably treated with a silane coupling agent.

  The resin composition of the present invention may contain other components. These other components include antioxidants, light stabilizers, ultraviolet absorbers and the like.

  In the resin composition of the present invention, in order to promote the reaction by heat, a curing catalyst is generally added in order to accelerate the reaction in response to heat or to adjust the curing temperature. Any of these known materials can be used as long as they have the effect of promoting the curing reaction.

  The antioxidant that can be used in the resin composition of the present invention is not limited as long as it is a known general one such as a phenol-based, sulfur-based, or phosphorus-based antioxidant. However, in view of the characteristics of the present invention, it is preferable to select a material that is colorless and difficult to be colored even when it is used for a long period of time as a circuit board after sealing or heat after curing.

  Examples of the phenolic antioxidant include monophenols, bisphenols, and high-molecular phenols.

  Specific examples of the sulfur-based antioxidant include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, and the like. .

  Examples of phosphorus antioxidants include phosphites and oxaphosphaphenanthrene oxides.

  These antioxidants can be used alone, but may be used in combination of two or more. The usage-amount of antioxidant is 0.008-1 mass part normally with respect to 100 mass parts of resin compositions of this invention, Preferably it is 0.01-0.5 mass part. In the present invention, a phosphorus-based antioxidant is preferable.

  As the light stabilizer that can be used in the resin composition of the present invention, known general ones can be used, and there is no particular limitation. However, in view of the characteristics of the present invention, it is preferable to select a material that is colorless and is difficult to be colored even when it is used for a long time or for heat during curing. Typical examples of these include hindered amines.

  As the ultraviolet absorber that can be used in the resin composition of the present invention, known general ones can be used, and there is no particular limitation. Examples of ultraviolet absorbers include benzotriazoles and hydroxyphenyltriazines, and can be used in combination with the light stabilizer.

  In the present invention, it is preferable to use an ultraviolet absorber having a low colorability over time. For example, propanoic acid-2- [4- [4,6-bis ([1,1′-biphenyl] -4-yl) -1,3,5-triazin-2-yl] -3-hydroxyphenyl]- Isooctyl ester (for example, Tinuvin 479, manufactured by Ciba Japan Co., Ltd.) and the like can be mentioned.

  When improving the coloring resistance of the present invention, a hydroxyphenyltriazine ultraviolet absorber and a hindered amine light stabilizer are used together.

  The resin composition of the present invention includes a butyral resin, an acetal resin, an acrylic resin, an epoxy-nylon resin, an NBR-phenol resin, and an epoxy-NBR resin as long as the properties such as transparency and hardness are not impaired. Resin components such as polyamide resin, polyimide resin, and silicone resin can be added as necessary.

  A silane coupling agent, a release agent, a leveling agent, a surfactant, a dye, a pigment, an organic light diffusing filler, and the like can also be added to the resin composition of the present invention.

  A known general metal salt can be added to the resin composition of the present invention. For example, carboxylic acid metal salts (zinc salts such as 2-ethylhexanoic acid, stearic acid, behenic acid, myristic acid, tin salts, zirconium salts) and phosphate ester metals (zinc salts such as octyl phosphoric acid, stearyl phosphoric acid), Examples thereof include metal compounds such as alkoxy metal salts (such as tributylaluminum and tetrapropylzirconium) and acetylacetone salts (such as acetylacetonezirconium chelate and acetylacetonetitanium chelate). These may be used alone or in combination of two or more. By adding a metal salt, the heat resistance and coloring resistance of the present invention can be improved.

  In the resin composition of the present invention, in order to promote the reaction by heat, a curing catalyst is generally added in order to accelerate the reaction in response to heat or to adjust the curing temperature. Any of these known materials can be used as long as they have the effect of promoting the curing reaction.

  Examples of the curing catalyst include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl- 2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2′-methylimidazole (1 ′)) ) Ethyl-s-triazine, 2,4-diamino-6 (2′-undecylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-ethyl-4-methylimidazole ( 1 ′)) Ethyl-s-triazine, 2,4-diamino-6 (2′-me Ruimidazole (1 ′)) ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxyalkyl Various imidazoles such as imidazole, 2-phenyl-4-hydroxyalkyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and imidazoles and phthalic acid, isophthalic acid, terephthalic acid Acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, maleic acid, salts with polyvalent carboxylic acids such as succinic acid, amides such as dicyandiamide, 1,8-diaza-bicyclo (5,4,0) undecene Diaza compounds such as 7 and their tetra Salts such as phenyl borate and phenol novolak, salts with the above polyvalent carboxylic acids or phosphinic acids, ammonium salts such as tetrabutylammonium bromide, cetyltrimethylammonium bromide, trioctylmethylammonium bromide, triphenylphosphine, tri (toluyl) phosphine Phosphines and phosphonium compounds such as tetraphenylphosphonium bromide, tetraphenylphosphonium tetraphenylborate, hexafluororostibin phosphonium salt, phenols such as 2,4,6-trisaminomethylphenol, tin octylate, cobalt octylate And organometallic compounds such as zinc octylate, zirconium octylate, nickel octylate and cobalt naphthenate. Furthermore, a microcapsule type curing catalyst in which a curing accelerator is used as a microcapsule can be used.

  Which of these curing catalysts is used should be appropriately selected depending on required properties. A curing catalyst is normally used in 0.001-15 mass parts with respect to 100 mass parts of all the resins in the resin composition of this invention.

  Further, fine particles having a primary particle size of 1 to 200 nanometers may be added to the thermosetting resin composition of the present invention. Examples of the fine particles include glass, silica, zirconium oxide, tin oxide, titanium oxide, zirconia, zinc oxide, indium tin oxide, antimony oxide, selenium oxide, yttrium oxide, aluminum oxide, and magnesium fluoride, and contain a dispersion solvent. It can be obtained from the market and used as a colloidal solution dispersed in a fine powder or solvent. Moreover, these can be used 1 type or in mixture of 2 or more types. Dispersion solvents include ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and dimethyldimethylacetamide, esters such as ethyl acetate and butyl acetate, nonpolar solvents such as toluene and xylene, and the like. What dissolves the components may be selected and used.

  In addition, a silane coupling agent, a release agent, a leveling agent, a surfactant, a dye, a pigment, an inorganic or organic light diffusion filler, and the like can be added.

  In the present invention, addition of a metal salt is preferable for the purpose of improving heat resistance and light resistance. Specifically, carboxylic acid metal salts (zinc salts such as 2-ethylhexanoic acid, stearic acid, behenic acid, myristic acid, tin salts, zirconium salts) and phosphate metal (zinc such as octyl phosphoric acid, stearyl phosphoric acid) Salts), metal compounds such as alkoxy metal salts (such as tributylaluminum and tetrapropylzirconium), and acetylacetone salts (such as acetylacetonezirconium chelate and acetylacetonetitanium chelate). These may be used alone or in combination of two or more.

  In the thermosetting resin composition of the present invention, each component can be uniformly mixed by a method similar to a conventionally known method to obtain a cured product. For example, an epoxy resin, an acid anhydride curing agent and, if necessary, a curing accelerator and other components are thoroughly mixed using an extruder, a kneader, a roll, etc., if necessary, until they are uniform. A curable resin composition is obtained. Since the thermosetting resin composition of the present invention is solid at room temperature, it can be cast, molded using a casting or transfer molding machine, and then cured by heating.

  The thermosetting resin composition of the present invention includes toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethyl acetate, butyl acetate, propylene glycol. It can be diluted with a solvent such as monomethyl ether or propylene glycol monomethyl ether acetate and used as a varnish. Since the thermosetting resin composition of the present invention is usually solid at normal temperature, it is more preferable to use it after diluting in a solvent. In particular, when the glass cloth is impregnated and used, it is diluted with a solvent.

  A solvent can be used as a 1 type, or 2 or more types of mixed solvent in consideration of the viscosity at the time of using the thermosetting resin composition of this invention, a drying rate, etc. Although the usage-amount of a solvent is based on the workability | operativity at the time of use and a drying rate, it is 10-200 mass parts normally with respect to 100 mass parts of thermosetting resin compositions of this invention, Preferably it is 15-100 mass parts.

  Even when the thermosetting resin composition of the present invention diluted with a solvent is obtained, it can be prepared by mixing and dissolving the respective components according to a conventional method. For example, each component is charged into a round bottom flask equipped with a stirrer and a thermometer, and stirred at 40 to 80 ° C. for 0.5 to 6 hours to obtain a varnish of a thermosetting resin composition. In this case, a method in which the epoxy resin varnish and the acid anhydride curing agent + curing catalyst or additive varnish are separately prepared and mixed at the time of use is particularly preferable. As described above, when the fine particles are added, the treatment can be performed by a generally known dispersion method such as a high-speed stirrer such as a homomixer or a sand mill, a microfluidizer, or a three roll.

  The varnish of the thermosetting resin composition of the present invention thus obtained is molded by a known method, dried and then cured by further heating. For example, it can be used in place of a mold by a method known per se such as pouring into a mold, drying after heating, curing, bar coater, air knife coater, die coater, gravure coater, offset printing, flexographic printing, screen printing, etc. A method of applying to a metal plate or a release film, heat drying and curing, a method of impregnating into a glass cloth, a method of curing after heat drying, a method of applying to glass or a transparent plastic substrate, heat drying and curing And a method of using it as a coating agent used together with a substrate. In the thermosetting resin composition of the present invention, the curing agent is volatilized during curing, the component ratio of the film is not changed, and the refractive index is not changed, so that a stable transparent film can be obtained. For this reason, it is suitable also for manufacture of an optical sheet. In addition, a smooth and excellent film can be obtained without causing the surface of the cured film to become rough due to the volatilization of the curing agent or to change the physical properties of the cured film.

  The drying temperature of the varnish of the thermosetting resin composition of the present invention is usually preferably 60 to 200 ° C., although it depends on the solvent used and the air volume. When the glass fiber sheet-like substrate such as glass cloth is impregnated with the varnish and the solvent is dried, it is also possible to obtain a prepreg by bringing the thermosetting resin composition of the present invention into a semi-cured state. . The drying conditions at this time are not particularly limited, but the temperature is preferably 100 to 180 ° C. and the time is preferably 1 to 30 minutes.

  A prepreg provided with a shape of the thermosetting resin composition of the present invention in a semi-cured state is also included in the present invention. The prepreg of the present invention includes a fiber impregnated with the thermosetting resin composition of the present invention.

  A cured product obtained by curing the thermosetting resin composition of the present invention is also included in the present invention. A cured product obtained by preparing a prepreg in which fibers are impregnated with the thermosetting resin composition of the present invention and then drying and curing is also included in the present invention. As described above, the thermosetting resin composition of the present invention is suitable for the production of optical sheets because there is no change in the refractive index due to volatilization of the curing agent during curing. In addition, as a curing temperature and time of the thermosetting resin composition of this invention, it is 2-200 hours at 80-200 degreeC. As a curing method, it can be cured at a high temperature at a stretch, but it may be cured at a low temperature of 150 ° C. or lower for a long time. For example, initial curing may be performed at 80 to 150 ° C., and post-curing may be performed at 100 to 200 ° C., and the curing reaction may be promoted by increasing the temperature stepwise.

  As the fiber (C-2) for producing the prepreg, a known commercially available fiber can be used. Among the glass fibers, E glass generally used for resin reinforcement has few alkali metal oxides and is suitable as an alkali-free glass for use in the present invention. There are various types of commercially available glass cloths such as woven fabrics, nonwoven fabrics, and knitted fabrics using glass fibers. In the present invention, there are no particular restrictions on the type thereof, but the thermosetting resin composition of the present invention is impregnated. In order to obtain a smooth cured product when cured, a glass cloth with small irregularities on the surface is suitable. Considering the drying and semi-curing conditions when producing the prepreg, the thickness of the glass cloth is usually 100 μm or less, preferably 50 μm or less. A prepreg having a thickness of about 25 μm or less may be produced, and two to several sheets may be stacked and integrated during curing to form the optical sheet of the present invention. The diameter of the glass fiber used for the glass cloth is preferably small in consideration of transparency, and is preferably 10 μm or less. In consideration of adhesion to the thermosetting resin composition of the present invention, the glass fiber is preferably treated with a silane coupling agent. The refractive index is 1.51 to 1.57, and 1.55 to 1.57 is more preferable as generally available.

  The cured thermosetting resin of the present invention can be used as a substitute for glass used in display devices such as liquid crystal displays, plasma displays, EL displays, and portable devices, and solar cells. In addition, peripheral materials for liquid crystal display devices such as light guide plates, prism sheets, polarizing plates, retardation plates, viewing angle correction films, adhesives, polarizer protective films, and other liquid crystal display device peripheral materials, antireflection films, and touch panel fronts It can also be used for face plates and optical correction films.

  Next, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited at all by the following examples. In the synthesis of the compound, the reaction was terminated when the disappearance of the raw alcohols was confirmed by gel permeation chromatography (hereinafter referred to as “GPC”). In the Examples, TMAC represents trimellitic anhydride chloride, HTAC represents nuclear hydrogenated trimellitic anhydride chloride, THF represents tetrahydrofuran, TMP represents trimethylolpropane, and MEK represents methyl ethyl ketone.

Synthesis Example 1 Preparation of Tris (2-hydroxyethyl) isocyanurate alkylene oxide adduct 21.6 g (0.1 mol) of tris (2-hydroxyethyl) isocyanurate as a reaction catalyst in a pressure-resistant vessel having a gas introduction part Sodium hydroxide 40 mg and alkylene oxide gas described in the table were introduced, and the mixture was heated at 150 ° C. for 3 hours. After cooling to room temperature, the reaction product was taken out and the catalyst was removed by filtration.

Abbreviations in Table EO: Ethylene oxide PO: Propylene oxide

Synthesis Example 2: Preparation of tris (2-hydroxyethyl) isocyanurate cyclic ether adduct Tris (2-hydroxyethyl) isocyanate was applied to a pressure-resistant reaction vessel equipped with a stirrer, a reflux condenser, and a stirrer while purging with nitrogen. Add 25.8 g (0.3 mol) of dimethyloxetane and 0.1 g of triarylsulfonium PF6 salt as a catalyst to 21.6 g (0.1 mmol) of nurate, stir at 120 ° C. for 12 hours, and add 43 g of dimethyloxetane adduct (abbreviated as THI3OX). Got.

Synthesis Example 3 Preparation of Tris (2-hydroxyethyl) isocyanurate cyclic ester adduct Tris (2-hydroxyethyl) isocyanurate while a nitrogen purge was applied to a flask equipped with a stirrer, reflux condenser, and stirrer. To 6 g (0.1 mmol), 34.3 g (0.3 mol) of caprolactone and 0.1 g of triarylsulfonium PF6 salt as a catalyst were added and stirred at 180 ° C. for 12 hours to obtain 53 g of caprolactone adduct (abbreviated as THI3CL).

Example 1: Synthesis of polyfunctional acid anhydride (A) A flask equipped with a stirrer, a reflux condenser, and a stirrer was purged with nitrogen while the amount of anhydride chloride (b) listed in the table was listed. (1.1 equivalent with respect to the hydroxyl group of (a)), 45 g of tetrahydrofuran was added to make a uniform solution. The solution was cooled to 5 ° C. with stirring, and (a) in the table was added in the amount (0.05 mol) in the table, pyridine (1.2 equivalents relative to the hydroxyl group of (a)) and 54 g of tetrahydrofuran were added. The solution made uniform was gradually added dropwise while maintaining the liquid temperature at 10 ° C. or lower. After completion of the dropping, the mixture was stirred at room temperature for 1 hour, then heated to 50 ° C., and the reaction was continued for 8 hours. Subsequently, the reaction solution was cooled to 20 ° C., and pyridine hydrochloride as an insoluble component was removed by filtration, and then the filtrate was concentrated. The concentrate was dissolved in 120 ml of ethyl acetate, washed 3 times with 30 ml of water, and then dried over anhydrous magnesium sulfate. After anhydrous magnesium sulfate was removed by filtration, the filtrate was concentrated, and the resulting concentrate was dissolved in 15 ml of ethyl acetate and recrystallized from toluene to obtain a product.

Comparative Example 1: Preparation of other trifunctional acid anhydrides Trifunctional acid anhydrides were synthesized according to Synthesis Example 1. The results are shown in the following table together with Synthesis Example 1.

Abbreviations in Table HTAC: Nuclear hydrogenated trimellitic anhydride chloride TMAC: Trimellitic anhydride chloride HTAC / TMAC: HTAC 50 mol%, TMAC 50 mol% mixture THI: Tris (2-hydroxyethyl) isocyanurate *: HTAC / TMAC (mol) Ratio) = 1/1

Example 2: Preparation of resin composition Polyfunctional acid anhydride obtained in Example 1 is listed in the table, 7 g of aliphatic epoxy resin EHPE-3150 (manufactured by Daicel Corporation, epoxy equivalent 181), aromatic 23 g of (4 (4 (1,1-bis (p-hydroxyphenyl) -ethyl) α, α-dimethylbenzyl) phenol) type epoxy resin (epoxy equivalent 206, total chlorine amount 550 ppm) as a type epoxy resin -310S (manufactured by Nippon Kayaku Co., Ltd .: liquid bisphenol A epoxy resin, epoxy equivalent 185, total chlorine amount 500 ppm), 0.3 g zinc octoate as other components, colloidal silica as particles (C-1) 41 g of methyl ethyl dispersion (Nissan Chemical Organosilica Sol MEK-ST, solid content 30% by weight), and the combined one was heated to 70 ° C. Combined to obtain a diluted composition of the resin composition of the present invention solids are 70 wt%.

Comparative Example 2: Preparation of thermosetting composition A thermosetting composition was prepared in the same manner as in Example 2.

Example 3 and Comparative Example 3: Preparation of cured product (glass cloth-epoxy composite sheet)
Methyl ethyl ketone was added to the curable resin composition of the present invention obtained in Example 2 and the curable resin composition obtained in Comparative Example to adjust the solid content to 50% by mass, and commercially available as (C-2). Glass cloth (E glass cloth: about 30 μm thick, plain weave) was put and impregnated. After pulling up the glass cloth, it was dried at 120 ° C. for 7 minutes. The sheet after drying was a solid film. This was further processed for 10 minutes at 150 ° C. while being pressed between PET films that had been subjected to release treatment, and semi-cured to obtain a prepreg. Thereafter, it was cured for 3 hours in a 150 ° C. dryer to obtain a cured product of the present invention. The obtained cured products were each measured for heat resistance, toughness, coloring resistance, and dimensional stability.

Evaluation methods and evaluation criteria for the resin composition and the cured film were as follows.
(1) Heat resistance: The Tg point of the cured resin composition was measured with a viscoelasticity measurement system (DMS-6000: manufactured by Seiko Denshi Kogyo Co., Ltd.) in a tensile mode at a frequency of 1 Hz. Judgment criteria are as follows.
A: Tg is 200 ° C. or higher
○: Tg is 190 ° C. or more and 199 ° C. or less Δ: Tg is 185 ° C. or more and 189 ° C. or less X: Tg is 184 ° C. or less (2) Flexibility: Cured sheet of cured resin composition is cut into strips having a width of about 1 cm. Then, after being wound around a metal rod having a diameter of 5 mm with a finger, it was returned to its original state, and the surface and the state inside the sheet were confirmed using an optical microscope.
○: Cracks and cracks are not observed and there is no change.
Δ: Cracks are observed inside the resin ×: Clear resin cracks are observed (3) Toughness: The cured film of the cured resin composition is cut with a cutter knife, and the end face is observed with an optical microscope Then, cracking and dust generation were evaluated.
◎: The end face was cut finely and could be cut without dust. ○: Although the end face was slightly rough, it could be cut without dust. △: The end face was rough and slightly dust was observed.
×: Clear resin cracking is observed

  As is clear from the above results, the cured product obtained using the acid anhydride of the present invention is excellent in heat resistance, flexibility and toughness. Although the cured product obtained using the acid anhydride of the comparative example is excellent in heat resistance, it is weak in bending (softness is weak).

  The alicyclic polyfunctional acid anhydride of the present invention and the curable resin composition thereof include paints and FRP for civil engineering and construction, and paints, resist inks, adhesives, sealants in the printed wiring board and semiconductor fields, etc. It is suitable for electrical and electronic materials such as sealants, and mainly for cured products used for display devices such as liquid crystal displays, plasma displays, EL displays, and portable devices, and solar cells.

Claims (8)

To a polyhydric alcohol (a) obtained by reacting tris (2-hydroxyethyl) isocyanurate with one or more selected from the group consisting of alkylene oxide, cyclic ether, and cyclic ester, nuclear hydrogenated trimellitic anhydride halide ( b-1) or a polyfunctional acid anhydride (A) obtained by reacting a mixture of nuclear hydrogenated trimellitic anhydride halide (b-1) and trimellitic anhydride halide (b-2). A thermosetting composition comprising the polyfunctional acid anhydride (A) according to claim 1 and a compound (B) having at least one epoxy group in one molecule. The thermosetting resin composition according to claim 2, further comprising particles (C-1) or fibers (C-2). The thermosetting resin composition according to claim 3, wherein the particles (C-1) are inorganic particles. The thermosetting resin composition according to claim 3, wherein the fiber (C-2) is a glass fiber. The thermosetting resin composition according to claim 3, wherein the fiber (C-2) is a glass cloth obtained by spinning glass fiber and further weaving it. The thermosetting resin composition according to any one of claims 2 to 6, wherein a shape is imparted in a semi-cured state. Hardened | cured material obtained by hardening | curing the thermosetting resin composition as described in any one of Claims 2 thru | or 7.