TW201815796A - Acid anhydride, curable resin composition using the same, cured product thereof and method of producing acid anhydride - Google Patents

Abstract

The present invention provides an acid anhydride and a curable resin composition containing the acid anhydride, the acid anhydride can provide a cured product excellent in heat resistance, transparency, toughness, and are represented by the following general formula (1). Wherein R1 represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, R2, R3 and R4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 11 carbon atoms or a group represented by the following formula (I), and at least one represents a substituent having a structure represented by the following formula (I). (* represents the binding position).

Description

 Anhydride, thermosetting resin composition using the same, method for producing the same, and method for producing an acid anhydride  

The present invention relates to an acid anhydride having a cyclitol skeleton, a curable resin composition containing the acid anhydride, and a method for producing the cured product and an acid anhydride. The cured product of the present invention is excellent in heat resistance, toughness, coloring transparency, surface smoothness, and dimensional stability.

The curable resin composition containing an epoxy resin is used as a resin excellent in heat resistance in fields such as construction, civil engineering, automobiles, and airplanes. In the field of semiconductor-related materials, epoxy resins used in electronic devices also have very high characteristic requirements, and applications in the field of optoelectronic related fields have been receiving attention in recent years.

Display devices such as liquid crystal displays, plasma displays, EL displays, and mobile devices have become popular among consumers, and are required to be improved in surface display, stereoscopic display, and the like while increasing in size, weight, and thickness. The optical member such as a display element or a front panel of such a device is widely used in order to satisfy various requirements such as transparency, hardness, chemical resistance, and gas barrier properties. However, the glass plate has a problem that it is easily broken and heavy. In order to solve this problem, there has been research on a plastic material such as epoxy resin as a substitute for the glass plate, and various proposals have been made.

For example, Patent Document 1 describes a transparent resin-based sheet for a liquid crystal display element using an epoxy resin, an acid anhydride-based curing agent, and an alcohol. In addition, 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.

A plastic material that replaces glass, such as this, is likely to cause warpage and cracking due to shrinkage during hardening in the manufacturing step, and it is difficult to obtain a smooth sheet. Further, when it is used, since the coefficient of linear expansion is larger than that of the glass plate, in addition to problems due to expansion and contraction during use, it is not possible to obtain sufficient color and heat resistance as a substitute for glass which is required by the market. Resistance to coloring, hardness and other properties.

The hardening agent of the epoxy resin generally used in this field is an acid anhydride type compound. In particular, an acid anhydride formed of a saturated hydrocarbon is used because it has excellent light resistance. In Patent Document 5, although the polybasic acid anhydride having a trimeric isocyanate structure is used as the acid anhydride, the cured product obtained from the trimeric isocyanate has insufficient transparency. Further, in Patent Document 6, although the transparency and the coloring resistance are excellent because of the alicyclic polyfunctional acid anhydride, since the main skeleton is a linear alkyl group, heat resistance is not sufficient.

 [Previous Technical Literature]    [Patent Literature]  

[Patent Document 1] Japanese Patent Laid-Open No. Hei 6-337408

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-233851

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2004-269727

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2005-156840

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2012-025670

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2015-098466

An object of the present invention is to provide an acid anhydride excellent in heat resistance, toughness, transparency, and surface smoothness of a cured product, a thermosetting resin composition containing the acid anhydride, a cured product thereof, and an acid anhydride.

The present inventors have found that an acid anhydride having a cyclic sugar alcohol skeleton maintains high optical properties, has high toughness, heat resistance, transparency, and has dimensional stability by adding fibers and particles.遂Complete the invention.

That is, the present invention relates to the following.

(1) An acid anhydride which is an acid anhydride represented by the following formula (1),

(wherein R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 11 carbon atoms or have a formula (I): A substituent of the structure, and at least one represents a substituent having a structure represented by the following formula (I).

(* indicates the key position).

(2) The acid anhydride according to the above formula (1), wherein the substituent having the structure represented by the above formula (I) is a substituent represented by the following formula (II).

(wherein R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms, and ** represents a bond position).

(3) an acid anhydride obtained by reacting an alcohol (A) represented by the following formula (2) with a carboxylic acid halide (B),

(wherein R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ Represents a hydrogen atom).

(4) The acid anhydride according to the above (3), wherein the carboxylic acid halide (B) is represented by the following formula (3).

(R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms).

(5) An acid anhydride obtained by reacting an alcohol (A) represented by the following formula (2) with one or more selected from the group consisting of a cycloalkoxy, a cyclic ether and a cyclic ester to obtain an alcohol (C), obtained by reacting the alcohol (C) with a carboxylic acid halide (B),

(wherein R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ Represents a hydrogen atom).

(6) The acid anhydride according to the above (5), wherein the carboxylic acid halide (B) is represented by the following formula (3).

(R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms).

(7) A thermosetting resin composition containing a compound having at least one epoxy group in one molecule, and an acid anhydride according to any one of the above items (1) to (6).

(8) The thermosetting resin composition according to the above (7), which further contains particles (D-1) or fibers (D-2).

(9) The thermosetting resin composition according to the above (8), wherein the particles (D-1) are inorganic particles.

(10) The thermosetting resin composition according to the above (8), wherein the fiber (D-2) is a glass fiber.

(11) The thermosetting resin composition according to the above (8), wherein the fiber (D-2) is a glass cloth obtained by spinning a glass fiber.

(12) A thermosetting resin composition according to any one of the above (7) to (11), wherein the thermosetting resin composition is imparted in a semi-hardened state.

(13) A cured product obtained by curing the thermosetting resin composition according to any one of the above (7) to (12).

(14) A method for producing an acid anhydride, which comprises reacting an alcohol (A) represented by the following formula (2) with a carboxylic acid halide (B) to produce an acid anhydride as described in the above (1) or (3). Production method,

(wherein R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ Represents a hydrogen atom).

(15) The method for producing an acid anhydride according to the item (5), wherein the alcohol (A) represented by the following formula (2) is selected from the group consisting of alkylene oxides, cyclic ethers and cyclic esters. One or more of the groups are reacted to obtain an alcohol (C), and the resulting alcohol (C) is reacted with a carboxylic acid halide (B).

(wherein R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ Represents a hydrogen atom).

The thermosetting resin composition containing the acid anhydride of the present invention has good stability, and is excellent in transparency, heat resistance, strength, and smoothness of the cured product, and is suitable for coatings for civil construction, FRP, and is suitable for printed circuit boards. /Electrical and electronic materials such as coatings, resist inks, adhesives, sealants, and encapsulants in the semiconductor field, LED encapsulants and optical waveguides, liquid crystal displays, plasma displays, EL displays, and mobile devices that further require high transparency Such as display devices and solar cells.

The invention is described below.

The acid anhydride of the present invention is represented by the following formula (1).

(wherein R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 11 carbon atoms or have a formula (I): The substituent of the structure, and at least one of them represents a substituent having a structure represented by the following formula (I).

(* indicates the bonding position)

The hydrocarbon group in R ¹ , R ² , R ³ and R ⁴ means an atomic group consisting only of a carbon atom and a hydrogen atom.

The carbon number of the hydrocarbon group is from 1 to 11. Specific examples thereof include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, linear or branched pentyl, and straight. a branched or branched hexyl, straight or branched heptyl, straight or branched octyl aliphatic hydrocarbon group; an alicyclic hydrocarbon group such as a cyclohexyl group, a methylcyclohexyl group or an ethylcyclohexyl group; An aromatic group such as a tolyl group, a naphthyl group or a methylnaphthyl group; an aromatic substituted alkyl group such as a benzyl group or a naphthylmethyl group; and the like. In the present invention, the cured product of the thermosetting resin composition containing the acid anhydride of the present invention is preferably an aliphatic hydrocarbon group.

The substituent having the structure represented by the above formula (I) is preferably a substituent represented by the following formula (II), although it is not particularly limited.

(R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms. ** represents a bond position).

The hydrocarbon group having 1 to 11 carbon atoms in R ⁵ of the above formula (II) is the same as those described for R ¹ to R ^{4 in} the above formula (1).

The production of the acid anhydride of the present invention is not particularly limited, and for example, it is preferred to react the alcohol (A) represented by the following formula (2) with the carboxylic acid halide (B).

(wherein R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ Represents a hydrogen atom).

The above alcohol (A) is a compound having a cyclic sugar alcohol skeleton and having at least one hydroxyl group in at least one molecule.

The source of the cyclic sugar alcohol skeleton of the alcohol (A) may, for example, be myo-inositol, scyllo-inositol, epi-inositol, cis-inositol (cis- Inositol), ononitol, and the like.

R' ¹ , R' ² , R' ³ and R' ^{4 of the} following general formula (2) are the same as those described for R ¹ to R ^{4 of} the above formula (1).

The carboxylic acid halide (B) in the present invention can be used for introducing an acid anhydride group into an alcohol to form an acid anhydride compound. Thereby, the acid anhydride group can be introduced without the ring-opening esterification of the acid anhydride group.

In the present invention, the carboxylic acid halide (B) is not particularly limited, but is preferably represented by the following formula (3).

(R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms).

Carbon number of R ⁵ in the general formula (3), the hydrocarbon group having 1 to 11, the same lines formula (II) of R ^5.

The carboxylic acid halide (B) in the present invention may, for example, be a trimellitic anhydride halide or a nuclear hydrogenated trimellitic anhydride halide. In particular, in the present invention, the alicyclic acid anhydride is preferred in that the cured product of the thermosetting resin composition containing the acid anhydride of the present invention is excellent in transparency and heat resistance.

The carboxylic acid halide (B) in the present invention may, for example, be a fluoride, a chloride, a bromide or an iodide, and among them, a chloride is preferred in terms of ease of reaction.

The synthesis of the acid anhydride of the present invention can be carried out in a known manner in the presence of a basic substance. The addition method of each compound in the reaction of the alcohol (A) and the carboxylic acid halide (B) is not particularly limited, and any addition method can be employed. For example, a method in which an alcohol (A) and a basic substance are dissolved in a solvent, and a carboxylic acid halide (B) which has been dissolved in a solvent is slowly dropped therein; or, conversely, as needed a method of dropping a mixed solution of an alcohol (A) and a basic substance in a carboxylic acid halide (B) dissolved in a solvent; and dropping a base in a mixed solution of a carboxylic acid halide (B) and an alcohol (A) a method of a substance; further, a solution of a halide-based solution and an alkaline substance is simultaneously dropped in a solution of the alcohol (A);

In the reaction of the alcohol (A) and the carboxylic acid halide (B) in the presence of a basic substance, a hydrochloride formed by neutralization of a basic substance is generated while the reaction proceeds. After the hydrochloride is removed by filtration, the filtrate is concentrated, whereby the crude product of the acid anhydride of the present invention can be obtained in high yield. This crude product is dissolved in a suitable solvent, concentrated after washing with water, and then dried under reduced pressure to obtain an acid anhydride of high purity. Further, if necessary, recrystallization is carried out in an appropriate solvent, whereby an acid anhydride having a higher purity can be obtained.

When the hydroxyl equivalent of the carboxylic acid halide (B) is 1.0, the amount of the alcohol (A) to be used is usually preferably from 0.6 to 1.0, more preferably from 0.8 to 1.0. As long as it is within this range, the hydroxyl group of the alcohol (A) is completely esterified, and the halide does not remain in the reaction system.

The solvent which can be used for the reaction of the carboxylic acid halide (B) and the alcohol (A) is not particularly limited as long as it is inert to the raw material, and examples thereof include tetrahydrofuran and 1,4-diene. An ether solvent such as an alkane or a 1,2-dimethoxyethane-bis(2-methoxyethyl)ether; an aromatic amine solvent such as a methylpyridine or a pyridine; such as acetone, methyl ethyl ketone or methyl a ketone solvent such as isobutyl ketone; an aromatic hydrocarbon solvent such as toluene or xylene; a halogen-containing solvent such as dichloromethane, chloroform or 1,2-dichloroethane; N-methyl-2-pyrrolidone; A guanamine solvent such as N,N-dimethylacetamide, N,N-diethylacetamide or N,N-dimethylformamide; a phosphorus-containing solvent such as hexamethylphosphoniumamine a sulfur-containing solvent such as dimethyl hydrazine; an ester solvent such as γ-butyrolactone, ethyl acetate or butyl acetate; a nitrogen-containing solvent such as 1,3-dimethyl-2-imidazolidinone; An aromatic solvent having a hydroxyl group such as phenol, o-cresol, m-cresol, p-cresol, o-chlorophenol, m-chlorophenol or p-chlorophenol. These solvents may be used singly or in combination of two or more.

When the alcohol (A) is reacted with the carboxylic acid halide (B), the reaction temperature is usually -10 ° C to 80 ° C, preferably 0 ° C to 70 ° C, more preferably 10 ° C to 60 ° C. In addition, although the solvent mentioned includes a cyclic ether and a cyclic ester, when the reaction temperature is higher than 80 ° C, the alcohol (A) further reacts with a cyclic ether or a cyclic ester, and an alcohol (A) and The case where the reaction rate of the carboxylic acid halide (B) is lowered. The reaction time is not particularly limited, but it is usually from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours. The reaction is usually carried out under normal pressure, and may be carried out under pressure or under reduced pressure as needed.

In the reaction for obtaining an acid anhydride, the concentration of the solute in the solvent is usually 5% by mass to 50% by mass, and it is preferably 10% by mass to 40% by mass in consideration of the regulation of the side reaction and the filtration step of the precipitation. This reaction is more preferably in the range of 10% by mass or more and 40% by mass or less of the solute in the solvent.

Usually, the reaction is carried out under a nitrogen gas atmosphere. The reaction vessel may be a closed reaction vessel or an open reaction vessel, but in order to keep the reaction in an inert gas atmosphere, in the case of an open type, it is sealed with an inert gas.

The alkaline substance is used to neutralize hydrogen chloride generated as the reaction progresses. The type of the basic substance to be used at this time is not particularly limited, and an organic tertiary amine such as pyridine, triethylamine or N,N-dimethylaniline, or an inorganic base such as potassium carbonate or sodium hydroxide can be used. Sexual substance. In the case where it can be obtained at a lower price, is liquid, and has high solubility and is easy to handle the reaction, pyridine or triethylamine is preferred. Moreover, in terms of the point that can be obtained at a lower price, it is preferred to use an inorganic alkaline substance.

The amount of the alkaline substance to be used is not particularly limited. However, when an excessive amount is used, the alkaline substance is mixed into the product, and the load for increasing the purification becomes large, so the number of moles of the carboxylic acid halide (B) is set. When it is 1.0, the alkaline substance is usually used in an amount of 1.0 mole to 30 moles, preferably 1.2 moles to 20 moles, and more preferably 1.5 moles to 10 moles.

In the water washing operation, although a part of the acid anhydride is hydrolyzed to become a carboxylic acid, the produced carboxylic acid can be easily changed back to the acid anhydride by heat treatment under reduced pressure. The temperature of the heat treatment under reduced pressure is 80 ° C to 200 ° C, preferably 100 ° C to 180 ° C, and the degree of pressure reduction is 50 KPa or less, preferably 10 KPa or less, and the upper limit of the heating time is not particularly limited, and is usually 10 minutes to 48 hours, preferably 30 minutes to 24 hours.

Furthermore, the acid anhydride of the present invention may be obtained by reacting one or more of the alcohol (A) represented by the above formula (2) with a group selected from the group consisting of alkylene oxides, cyclic ethers and cyclic esters. An alcohol (C) is an acid anhydride obtained by reacting the alcohol (C) with a carboxylic acid halide (B).

The alcohol (C) in the present invention is obtained by reacting an alcohol (A) with an alkylene oxide, a cyclic ether or a cyclic ester.

The alkylene oxide used in the present invention means a compound having a cyclic ether of a three-membered ring.

The alkylene oxide preferably has a carbon number of 2 to 8. For example, ethylene oxide, propylene oxide, butylene oxide, benzene oxide, etc. are mentioned. These alkylene oxides may be used alone or in combination of two or more kinds as needed. Among them, in the present invention, at least one selected from the group consisting of ethylene oxide and propylene oxide is preferred because it is easy to obtain 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 having a cyclic hydrocarbon of 4 or more members are substituted with oxygen.

The cyclic ether is preferably a 4- to 6-membered ring, and specific examples thereof include oxetane, tetrahydrofuran, tetrahydropyran, and the like. These cyclic ethers may be used alone or in combination of two or more kinds as needed. Among them, tetrahydrofuran is preferred in the present invention because it is easy to obtain and inexpensive.

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

The cyclic ester preferably has a carbon number of 2 to 6. Specific examples of the cyclic ester include ethyl lactone, propiolactone, butyrolactone, valerolactone, and caprolactone. These cyclic esters may be used alone or in combination of two or more kinds as needed. Among them, caprolactone is preferred in the present invention because it is easy to obtain and inexpensive.

The alkylene oxide, the cyclic ether and the cyclic ester are used in an amount of from 0.5 to 6.0 equivalents, preferably from 0.8 to 2.0 equivalents, per equivalent of the hydroxyl group of the alcohol (A). As long as it is in this range, the heat resistance and toughness of the obtained cured product can be made good.

When the alcohol (A) is reacted with an alkylene oxide, a cyclic ether or a cyclic ester to produce a polyol (C), the reaction temperature is usually from 80 ° C to 250 ° C, preferably from 90 ° C to 220 ° C, and from 100 ° C to 200 ° C is better. The reaction time is not particularly limited and is usually from 10 minutes to 48 hours, preferably from 30 minutes to 24 hours. The reaction is usually carried out under normal pressure, but it can also be carried out under pressure or under reduced pressure as needed.

In particular, a compound which is vaporized at room temperature such as ethylene oxide or propylene oxide is preferably reacted in a pressure resistant container.

The conditions for reacting the alcohol (C) with the carboxylic acid halide (B) may be the same as those described above for reacting the alcohol (A) with the carboxylic acid halide (B).

The acid anhydride of the present invention thus obtained can be further refined. In the purification method at this time, recrystallization, sublimation, washing, activated carbon treatment, column chromatography, or the like can be arbitrarily performed. Further, these purification methods may be repeatedly carried out, or these purification methods may be combined and carried out. The purity of the acid anhydride of the present invention thus obtained is, for example, 90% or more, and 95% or more, in terms of the area of the peak obtained by analysis such as gel permeation chromatography (hereinafter referred to as "GPC"). Good, more than 98% is better.

The storage of the acid anhydride is desirably kept at a low temperature to avoid high temperature to prevent ring opening of the acid anhydride ring due to hydrolysis. Specifically, as long as it is stored in a refrigerator in a container having good sealing properties, it can be stored for a long period of time. Further, the acid anhydride may be used in the subsequent polymerization reaction immediately after the purification in order to prevent moisture absorption. The storage period at this time is usually within 100 hours, preferably within 50 hours, and preferably within 24 hours.

The acid anhydride of the present invention may be combined with a compound of a hardening reaction to form a thermosetting resin composition. In this case, the anhydride of the present invention functions as a hardener. In this case, the compound having a functional group reactive with an acid anhydride group and a carboxyl group due to heat is not particularly limited, and a compound having an epoxy group is particularly preferably used.

In this case, in order to obtain a suitable thermosetting resin composition, a compound containing at least two functional groups reactive with an acid anhydride group in one molecule is preferably used.

The compound having an epoxy group represented by the present invention can be used as long as it is a compound having at least one epoxy group in one molecule. Hereinafter, an aromatic epoxy resin or an aliphatic epoxy resin which is a compound having at least one epoxy group in one molecule which is suitably used in the present invention will be described.

Examples of the aromatic epoxy resin include a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a biphenyl-phenol type epoxy resin, and a naphthol type epoxy resin. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin and other bisphenol type epoxy resin; trisphenol methane type epoxy resin, glyoxal type epoxy resin, (4 (4 (1,1-bis(p-hydroxyphenyl)-ethyl)α,α-dimethylbenzyl)phenol) epoxy resin or the like. Among these resins, heat resistance and coloring resistance are considered, and in the present invention, bisphenol A type epoxy resin, (4(4,1,1-bis(p-hydroxyphenyl)-ethyl)α) An α-dimethylbenzyl phenol) 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. An epoxy resin having an aliphatic cyclic structure characterized by having at least one cyclic aliphatic structure in one molecule. For example, terpene diphenol, and phenols (phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and aliphatic cyclic structure diene (dicyclopentane) Polycondensate of alkene and norbornadiene, hexahydroxyindole, etc., and glycidyl etherate derived from the modified substance, hydrogenated bisphenol (bisphenol A, bisphenol F) type epoxy resin, alicyclic An epoxy resin having a cyclohexyl structure in a molecule such as an epoxy resin, an epoxy resin having a dicyclopentadiene structure, an epoxy resin having a trimeric isophthalic acid triglycidyl ester structure, or the like. Specific examples thereof include cyclohexanediol diglycidyl ether, 3,4-epoxycyclohexenemethyl-3', 4'-epoxycyclohexene carboxylate, 2,2- A 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of bis(hydroxyalkyl)-1-butanol.

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 hexane diglycidyl ether.

In order to improve the properties of the thermosetting resin composition, for example, in order to improve strength and dimensional stability, impart toughness or optical properties, it is also widely used in combination with particles, fibers, and the like. However, in this composite aspect, the toughness of the resin becomes more important. When the toughness of the resin is insufficient, the interface between the cured resin, the particles, and the fibers is broken, the cured product is easily broken, and the flexibility is lowered due to peeling. In general, when a soft component is used for the resin in order to prevent such a situation, heat resistance and mechanical strength are lowered. The cured product of the acid anhydride of the present invention is suitable for a composite composition with particles and fibers because it does not lose strength and toughness even if it maintains high heat resistance. In the present invention, the particles and the fibers are preferably one which is incompatible with the acid anhydride of the present invention and a compound having at least one epoxy group in one molecule.

Examples of the particles (D-1) used in the thermosetting resin composition of the present invention include polymethyl methacrylate, polystyrene, and nylon of organic particles; talc of inorganic particles, calcined clay, and uncalcined clay. , mica such as mica and glass, oxides such as titanium oxide, aluminum oxide, cerium oxide and lanthanum oxide, hydrogen carbonate such as calcium carbonate, magnesium carbonate and hydrotalcite, aluminum hydroxide, magnesium hydroxide and calcium hydroxide. Sulfate, aluminum nitride, boron nitride and tantalum nitride such as oxides, barium sulfate, calcium sulfate and calcium sulfite, such as sulfate or sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate and sodium borate A fluoride such as a nitride or the like, such as magnesium fluoride or calcium fluoride, can be used as a fine powder containing no dispersion solvent or a colloidal solution dispersed in a dispersion solvent. Further, these particles may be used alone or in combination of two or more. As the solvent to be dispersed, a ketone such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone or dimethyl dimethyl acetamide, an ester such as ethyl acetate or butyl acetate, toluene or the like may be selected and used. Any component such as a non-polar solvent such as toluene which can dissolve the thermosetting resin composition of the present invention may be used. Further, in terms of dimensional stability, inorganic particles are preferred. In particular, in terms of versatility and low price, alumina and cerium oxide are preferred.

The fiber (D-2) used in the thermosetting resin composition of the present invention may, for example, be carbon fiber, glass fiber, casein fiber, peanut protein fiber, zein fiber, soybean protein fiber, algae fiber or chitin fiber. , mannan fiber, rubber fiber, cellulose fiber, nylon fiber, polyvinylidene chloride fiber, polyvinyl chloride fiber, polyester fiber, polyacrylonitrile fiber, modified modacrylic fiber, polyethylene Fiber, polypropylene fiber, polystyrene fiber, polyether ester fiber, polyurethane fiber, and the like. These fibers may be used alone or in combination of two or more. Among them, from the viewpoint of generality, glass fiber is preferred. Further, the glass fiber has various aspects such as a woven fabric, a non-woven fabric, and a woven fabric. The present invention is not particularly limited in the present invention, but is obtained in order to obtain a thermosetting resin composition of the present invention and hardened. A cured product excellent in dimensional stability is preferably a glass cloth. When the adhesion to the thermosetting resin composition of the present invention is considered, it is preferred that the glass fiber is treated with a decane coupling agent.

The thermosetting resin composition of the present invention may contain other components. Examples of such other components include an antioxidant, a photosensitizer, and an ultraviolet absorber.

In the thermosetting resin composition of the present invention, in order to promote the reaction by heat, to promote the reaction of induction heat, or to adjust the curing temperature, a curing catalyst is usually added. The catalyst can be used as long as it has an effect of promoting the above-mentioned hardening reaction.

The antioxidant which can be used in the resin composition of the present invention is not particularly limited as long as it is generally known as a phenol type, a sulfur type, or a phosphorus type antioxidant. However, in view of the characteristics of the present invention, it is preferable to select a colorless one, and it is not easy to be colored even when it is used for a long time even when the heat is hardened and the circuit board after packaging is used.

Examples of the phenolic antioxidant include monophenols, bisphenols, and polymeric phenols.

Specific examples of the sulfur-based antioxidant include dilaurin 3,3'-thiodipropionate, 3,3'-thiodipropionate dimyristate, and 3,3'-thiodipropionic acid. Distearyl ester and the like.

Examples of the phosphorus-based antioxidant include phosphites and oxaphosphaphenanthrene oxides.

These antioxidants may be used alone or in combination of two or more. The antioxidant is used in an amount of usually 0.008 to 1 part by mass, and preferably 0.01 to 0.5 part by mass, based on 100 parts by mass of the resin composition of the invention. Further, in the present invention, a phosphorus-based antioxidant is preferred.

The light stabilizer which can be used in the thermosetting resin composition of the present invention can be used without any particular limitation. However, in view of the characteristics of the present invention, it is preferred to select a material which is colorless and which is not easily colored even when it is used for heat during curing and for a long period of time. Representative examples of such a compound include hindered amines and the like.

The ultraviolet absorber which can be used in the thermosetting resin composition of the present invention can be used without any particular limitation. Examples of the ultraviolet absorber include a benzotriazole system and a hydroxyphenyl group. It can also be used in combination with the above-mentioned light stabilizer.

In the present invention, it is preferred to use an ultraviolet absorber having a low coloring property over time. For example, propionate-2-[4-[4,6-bis([1,1'-biphenyl]-4-yl)-1,3,5-three -2-yl]-3-hydroxyphenyl]-isooctyl ester (for example, Tinuvin 479, manufactured by Ciba Japan Co., Ltd.) or the like.

When it is desired to enhance the coloring resistance of the present invention, it is a hydroxyphenyl three A UV absorber is used together with a hindered amine light stabilizer.

In the thermosetting resin composition of the present invention, a butyral resin, an acetal resin, an acrylic resin, or an epoxy-nylon resin may be added as needed without impairing characteristics such as transparency and hardness. A resin component such as an NBR-phenol resin, an epoxy-NBR resin, a polyamine resin, a polyamidene resin, or a polyoxyn resin.

In the thermosetting resin composition of the present invention, a decane coupling agent, a release agent, a leveling agent, a surfactant, a dye, a pigment, an organic light-diffusing filler, or the like may be added.

A commonly known metal salt can also be added to the thermosetting resin composition of the present invention. For example, a metal carboxylate (zinc salt, tin salt, zirconium salt such as 2-ethylhexanoic acid, stearic acid, behenic acid or myristic acid) and a phosphate metal (octylphosphoric acid or stearyl group) may be mentioned. a metal compound such as a zinc salt of phosphoric acid or the like, a metal alkoxide (such as tributylaluminum or tetrapropylzirconium), or an acetonide salt (such as a acetonium acetonide zirconium chelate or an acetonitrile acetonide chelate compound) Wait. These metal compounds may be used alone or in combination of two or more. The heat resistance and coloring resistance of the present invention can be improved by the addition of a metal salt.

In the thermosetting resin composition of the present invention, a curing catalyst is usually added in order to promote a reaction by heat, to promote induction heat, or to adjust a curing temperature. The catalyst can be used as long as it has an effect of promoting the above-mentioned hardening reaction.

Examples of the curing catalyst include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, and 1-phenylene. 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyano Ethyl-2-undecylimidazole, 2,4-diamino-6(2'-methylimidazolium(1'))ethyl-all three 2,4-Diamino-6(2'-undecylimidazolium (1')) ethyl-all three 2,4-Diamino-6(2'-ethyl-4-methylimidazolium (1'))ethyl-all three 2,4-Diamino-6(2'-methylimidazolium(1'))ethyl-all three /Trimeric isocyanate adduct, 2:3 adduct of 2-methylimidazolium tripolyisocyanate, 2-phenylimidazole trimer isocyanate adduct, 2-phenyl-3,5 -dihydroxyalkylimidazole, 2-phenyl-4-hydroxyalkyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole Various imidazoles, and such imidazoles and polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalene dicarboxylic acid, maleic acid, oxalic acid, etc. a salt of an acid, a guanamine such as dicyanodiamine, a diazepine compound such as 1,8-diaza-bicyclo(5,4,0)undecene-7, and the tetraphenyl borate a salt such as an ester or a phenol novolak; a salt of the above polycarboxylic acid or phosphonic acid; an ammonium salt such as tetrabutylammonium bromide, cetyltrimethylammonium bromide or trioctylmethylammonium bromide; , phosphine or anthraquinone compounds such as triphenylphosphine, tris(tolyl)phosphine, tetraphenylphosphonium bromide, tetraphenylphosphonium tetraphenyl borate, hexafluoroantimony salt, 2,4,6- Phenolics such as ginsengmethylphenol, tin octoate, cobalt octoate, zinc octoate, zirconium octoate, nickel octoate, cobalt naphthenate and other organic metals Thereof and the like. Further, a microcapsule-type curing catalyst or the like in which a curing accelerator is used as a microcapsule may be mentioned.

Which of these hardening catalysts is used should be selected according to the required characteristics. The curing catalyst is usually used in an amount of from 0.001 to 15 parts by mass based on 100 parts by mass of the total of the resin in the resin composition of the present invention.

Further, fine particles having a primary particle diameter of 1 to 200 nm may be added to the thermosetting resin composition of the present invention. Examples of the fine particles include glass, cerium oxide, zirconium oxide, tin oxide, titanium oxide, zirconia, zinc oxide, indium tin oxide, antimony oxide, selenium oxide, antimony oxide, and aluminum oxide. Magnesium fluoride or the like can be used as a fine powder which does not contain a dispersion solvent, and a colloidal solution which has been dispersed in a solvent, and is obtained from the market. Further, these fine particles may be used alone or in combination of two or more. As the solvent to be dispersed, a ketone such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone or dimethyl dimethyl acetamide, an ester such as ethyl acetate or butyl acetate, toluene or the like may be selected and used. Any component such as a non-polar solvent such as toluene which can dissolve the thermosetting resin composition of the present invention may be used.

Further, a decane coupling agent, a release agent, a leveling agent, a surfactant, a dye, a pigment, an inorganic or organic light-diffusing filler, or the like may be added.

In the present invention, in order to improve heat resistance and light resistance, it is preferred to add a metal salt. Specific examples thereof include a metal carboxylate (zinc salt, tin salt, zirconium salt such as 2-ethylhexanoic acid, stearic acid, behenic acid, and myristic acid) and a phosphate metal (octyl phosphate, a zinc salt such as stearyl phosphate or the like, an alkoxy metal salt (such as tributyl aluminum or tetrapropyl zirconium), or an acetonide salt (a zirconium acetonide chelate, an acetonitrile acetonide chelate compound, etc.) Such as metal compounds and the like. These may be used alone or in combination of two or more.

The thermosetting resin composition of the present invention can be uniformly mixed with a component in the same manner as a conventionally known method to obtain a cured product. For example, an epoxy resin, an acid anhydride (hardener) of the present invention, and an optional hardening accelerator and other components are sufficiently mixed until necessary by using an extruder, a kneader, a roll, or the like. A thermosetting resin composition of the invention. Since the thermosetting resin composition of the present invention is solid at normal temperature, it may be formed by casting or molding using a transfer molding machine after melting, and then heating and curing.

Further, the thermosetting resin composition of the present invention may be toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, dimethylformamide, dimethyl group. A solvent such as acetamide, N-methylpyrrolidone, ethyl acetate, butyl acetate, propylene glycol monomethyl ether or propylene glycol monomethyl ether acetate is diluted with a varnish to be used. The thermosetting resin composition of the present invention is usually a solid at normal temperature, and therefore it is more preferable to use it after dilution with a solvent, which is easier to handle. In particular, when it is impregnated with a glass cloth and used, it is diluted with a solvent.

When the thermosetting resin composition of the present invention is used, the viscosity, the drying rate, and the like can be used, and one type of solvent or a mixture of two or more types can be used. The use ratio of the solvent varies depending on the workability at the time of use and the drying speed, and is usually 10 to 200 parts by mass, preferably 15 to 100 parts by mass, per 100 parts by mass of the thermosetting resin composition of the present invention.

When the thermosetting resin composition of the present invention diluted with a solvent is obtained, it may be prepared by mixing and dissolving each component in accordance with a usual method. For example, a varnish of a thermosetting resin composition can be obtained by charging each component into a round bottom flask equipped with a stirring device and a thermometer, and stirring at 40 to 80 ° C for 0.5 to 6 hours. In this case, it is particularly preferable to adjust the varnish of the epoxy resin, the sclerosing agent of the acid anhydride curing agent + the curing catalyst, and the additive, and to remix the film during use. As described above, when the fine particles are added, it may be treated by a generally known dispersion method such as a high-speed agitator such as a homogenizer or a sand mixer, a microfluidizer, or a three-way roller.

The varnish of the thermosetting resin composition of the present invention thus obtained can be formed by a known method, dried, and then hardened by heating. For example, a method of pouring into a metal mold, and drying it by heating and drying; using a bar coater, an air knife coater, a die coater, a gravure coater, a plate printing, a flexographic printing, a screen printing a method in which a printing method or the like is applied to a metal plate, a release film, or the like in place of a mold, and is dried by heating and drying, and is then impregnated in a glass cloth, and dried by heating and drying; or coated A method of using a coating agent on a glass or a transparent plastic substrate, which is dried by heating and then hardened to be used together with a substrate. In the thermosetting resin composition of the present invention, since the refractive index of the film is not changed when the curing agent is volatilized, the refractive index of the film is changed to change the refractive index, so that a stable transparent film can be obtained. Therefore, it is also suitable for the manufacture of optical sheets. Further, the surface of the cured film is not roughened by the volatilization of the curing agent, and the physical properties of the cured film are not changed, so that a film having excellent smoothness and hardness can be obtained.

The drying temperature of the varnish of the thermosetting resin composition of the present invention varies depending on the solvent to be used and the amount of air, but is usually 60 to 200 °C. The varnish is impregnated into a glass fiber-like substrate such as glass cloth, and when the solvent is dried, the thermosetting resin composition of the present invention may be semi-cured to obtain a prepreg. The drying conditions at this time are not particularly limited, but are preferably from 100 to 180 ° C for a period of from 1 minute to 30 minutes.

The present invention also includes a prepreg in which the thermosetting resin composition of the present invention is imparted in a semi-hardened state. The prepreg of the present invention includes one in which the thermosetting resin composition of the present invention is impregnated into the fiber.

The present invention also includes a cured product obtained by curing the thermosetting resin composition of the present invention. The present invention also includes a cured product obtained by impregnating a thermosetting resin composition of the present invention with a fiber to prepare a prepreg, followed by drying and curing. As described above, the thermosetting resin composition of the present invention is suitable for the production of optical sheets because it does not cause a change in refractive index when the curing agent volatilizes during curing. Further, the curing temperature and time of the thermosetting resin composition of the present invention are preferably from 80 ° C to 200 ° C for 2 to 200 hours. As the curing method, it may be cured at a high temperature for a short period of time, or may be cured at a low temperature of 150 ° C or lower for a long period of time. It is also possible to carry out initial hardening between 80 ° C and 150 ° C, post-hardening between 100 ° C and 200 ° C, and gradually increase the temperature to carry out a hardening reaction.

A known commercially available product can be used to produce the above-mentioned fiber (D-2) for the prepreg. Among the glass fibers, E glass which is used for resin reinforcement can be usually used, and it can be used as an alkali-free glass having a small amount of alkali metal oxide, and is suitable for the use of the present invention. The commercially available glass cloth has various aspects such as a woven fabric, a non-woven fabric, and a knitted fabric using glass fibers, and the type thereof is not particularly limited in the present invention. However, in order to impregnate the thermosetting resin composition of the present invention and harden it to obtain a smooth cured product, it is suitable for those having a small surface unevenness of the glass cloth. When the conditions for drying and semi-hardening in the preparation of the prepreg are considered, the thickness of the glass cloth is usually 100 μm or less, preferably 50 μm or less. It is also possible to use a prepreg having a thickness of about 25 μm or a thickness of 25 μm or less, and to laminate two sheets to several sheets at the time of curing to form an optical sheet of the invention. The diameter of the glass fiber used for the glass cloth is preferably as small as possible, and preferably 10 μm or less. Further, when the adhesion to the thermosetting resin composition of the present invention is considered, the glass fiber is preferably treated with a decane coupling agent. The refractive index is preferably from 1.51 to 1.57, and is usually preferably from 1.55 to 1.57.

The cured product of the thermosetting resin composition of the present invention can be used as a substitute for glass used for display devices such as liquid crystal displays, plasma displays, EL displays, and mobile devices, and solar cells. In addition, liquid crystal display peripheral materials such as a liquid crystal film such as a light guide plate, a ruthenium sheet, a polarizing plate, a phase difference plate, a viewing angle correction film, an adhesive, and a polarizer protective film may be used, and an antireflection film or a touch panel may be used. Front panel, optical correction film, etc.

 [Examples]  

Next, the present invention will be described in more detail by way of examples. Further, the present invention is not limited to the following embodiments. In the synthesis of the compound, when the disappearance of the raw material alcohol is confirmed by gel permeation chromatography (hereinafter referred to as "GPC"), the reaction is completed. Further, in the examples, HTAC represents a nuclear hydrogenated trimellitic anhydride chloride, THF represents tetrahydrofuran, DMF represents N,N-dimethylformamide, and MEK represents methyl ethyl ketone.

Synthesis Examples 1-1 to 3: Synthesis of myoinositol-1,3,5-orthoester (myo-inositol 1,3,5-orthoester)

Nitrogen gas purge was carried out in a flask equipped with a stirrer, a reflux cooling tube, and a stirring device, and 9.0 g (50 mmol) of myo-inositol and 100 ml of DMF were added in the amounts shown in Table 1 below, and Table 1 below. The orthoester and the acid catalyst described in the above were stirred at 100 ° C for 3 hours. Next, the reaction liquid was cooled to 20 ° C, and 5 g of triethylamine was added thereto, and the mixture was stirred for 1 hour, and then the reaction liquid was concentrated. The obtained concentrate was dissolved in 50 mL of methanol and cooled, thereby being recrystallized to obtain a product.

Abbreviation

PTSA-1H ₂ O: p-toluenesulfonic acid monohydrate

CSA: 10-camphorsulfonic acid

Synthesis Example 2-1: Preparation of alkylene oxide adduct of myoinositol-1,3,5-orthoacetate

In a pressure-resistant container having a gas introduction portion, 6.1 g (30 mmol) of myoinositol-1,3,5-orthoacetate, 12 mg of sodium hydroxide as a reaction catalyst, and 4.0 g of ethylene oxide gas were introduced ( 90 mmol), heated at a temperature of 150 ° C for 3 hours. After cooling to room temperature, the reactant was taken out, and the catalyst was removed by filtration to obtain 9.0 g of ethylene oxide adduct (abbreviated as IOA3EO).

Synthesis Example 2-2: Preparation of cyclic ester adduct of myoinositol-1,3,5-orthoacetate

Nitrogen gas scavenging was carried out in a pressure-resistant reaction vessel equipped with a stirrer, a reflux cooling tube, and a stirring device, and dimethyloxo was added to 6.1 g (30 mmol) of myoinositol-1,3,5-orthoacetate. 7.7 g (90 mmol) of cyclobutane and 0.05 g of triarylsulfonium PF ₆ salt as a catalyst were stirred at 120 ° C for 12 hours to obtain 12.6 g of dimethyloxetane adduct (abbreviated as IOA 3OX).

Synthesis Example 2-3: Preparation of cyclic ester adduct of myoinositol-1,3,5-orthoacetate

In a flask equipped with a stirrer, a reflux cooling tube, and a stirring device, nitrogen scavenging was performed while adding 10.3 g (90 mmol) of caprolactone to 6.1 g (30 mmol) of myoinositol-1,3,5-orthoacetate. 0.05 g of a triarylsulfonium PF ₆ salt as a catalyst was stirred at 180 ° C for 12 hours to obtain 9.6 g of a caprolactone adduct (abbreviated as IOA 3CL).

Examples 1-1 to 7 and Comparative Examples 1-1 to 2: Synthesis of polyfunctional acid anhydrides

In a flask equipped with a stirrer, a reflux cooling tube, and a stirring device, nitrogen scavenging was carried out, and THF was added to the acid halide described in Table 2 below to prepare a homogeneous solution. After the solution was stirred and cooled to 5 ° C, the amount of pyridine described in the table was added to the alcohol described in Table 2 below, and the uniform solution was added to the THF to keep the temperature below 10 ° C while relaxing. Slowly drip. After completion of the dropwise addition, the mixture was stirred at room temperature for 1 hour, and then heated to 50 ° C to allow the reaction to continue for 8 hours. Next, the reaction liquid was cooled to 20 ° C, and the insoluble component of the pyridine hydrochloride was removed by filtration, and then the filtrate was concentrated. The obtained concentrate was dissolved in ethyl acetate, washed with water three times, and dried over anhydrous magnesium sulfate. After removing anhydrous magnesium sulfate by filtration, the filtrate was concentrated to obtain a product.

Abbreviation

PE4EO: Reactive substance of pentaerythritol (PE) and ethylene oxide (EO)

THI: ginseng (2-hydroxyethyl) trimeric isomerate

HTAC: nuclear hydrogenation of trimellitic anhydride chloride

TMAC: trimellitic anhydride chloride

Examples 2-1 to 7 and Comparative Examples 2-1 to 2: Modulation of a resin composition using an acid anhydride

Anhydride, an aliphatic epoxy resin EHPE-3150 (2,2-bis(hydroxymethyl) obtained in Examples 1-1 to 7 and Comparative Examples 1-1 to 2, which are described in the following Table 3, , 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 1-butanol, manufactured by Daicel Co., Ltd., epoxy equivalent 181) 2.3 g, as an aromatic Type epoxy resin NC-6300 (4(4,1,1-bis(p-hydroxyphenyl)-ethyl)α,α-dimethylbenzyl)phenol) epoxy resin, Japanese chemical RE-310S (Liquid Bisphenol A Epoxy Resin, manufactured by Nippon Kayaku Co., Ltd., epoxy resin), which is also made of an aromatic epoxy resin, is 6.1 g of an epoxy resin equivalent of 650 ppm. The equivalent of 185, the total chlorine amount of 550 ppm), and the combination of 0.1 g of zinc octoate as another component were heated to 70 ° C, and mixed to obtain a dilution of the resin composition of the present invention having a solid content of 70% by mass. Composition.

Examples 3-1 to 5: Modulation of a resin composition using an acid anhydride

Using the 7.5 g of the acid anhydride obtained in Example 1-4 and the epoxy resin described in the following Table 4 in the amounts described in Table 4 below as the epoxy resin, the same as those of Examples 2-1 to 7 The operation obtained the composition.

Abbreviation

NER-1302: Polyfunctional bisphenol A epoxy resin, manufactured by Nippon Kayaku Co., Ltd.

jER1001: Liquid bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation

jER828: liquid bisphenol A epoxy resin, manufactured by Mitsubishi Chemical Corporation

EOCN-103S: o-cresol novolac epoxy resin, manufactured by Nippon Kayaku Co., Ltd.

Examples 4-1 to 7 and Comparative Examples 4-1 to 2: 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 2 to prepare a solid content of 50% by mass, and was added as (D-2). A commercially available glass cloth (E glass cloth: about 30 μm thick, plain weave) was impregnated. After picking up the glass cloth, it was dried at 120 ° C for 7 minutes. The dried flakes are solid films. The film was further poured into a release-treated PET film, and treated at 150 ° C for 10 minutes while being pressurized, and semi-hardened to obtain a prepreg. Then, it was hardened in a dryer at 150 ° C for 3 hours to obtain a cured product of the present invention. The heat resistance, toughness, and transparency of the obtained cured product were measured, respectively.

The evaluation methods and evaluation criteria of the resin composition and the cured film are as follows.

(1) Heat resistance: In the viscoelasticity measurement system (RSA-G2, manufactured by TA), the Tg point of the cured resin composition was measured in a tensile mode at a frequency of 1 Hz.

(2) Toughness: The hardened film of the hardened resin composition was cut by a cutting blade, and the end surface thereof was observed with an optical microscope to evaluate cracking and dust generation.

◎: The end face is cut well, and the cutting does not produce dust.

○: Although it is cut to a very slight roughness on the end face, the cutting does not produce dust.

△: the end face is rough, and some dust is observed.

×: The resin cracking was clearly observed

(3) Transparency: The cured film of the cured resin composition was visually confirmed and evaluated. Further, the yellowness YI and haze were measured by a spectrophotometer and a haze meter.

From the above results, it is understood that the cured product obtained by using the acid anhydride of the present invention is excellent in heat resistance, toughness, and transparency. The acid anhydride of the present invention used in the cured products of Examples 4-1 to 3 has a trifunctional acid anhydride, and the alcohol which is a parent core is aliphatic and has a large molecular weight, so that it is excellent in heat resistance and transparency. Further, the cured product obtained by using the acid anhydrides of Examples 4 to 4 has excellent rigidity and transparency because the core has a rigid skeleton and a soft alkyl chain. In Example 4-7, although coloring due to aromatics was observed, high heat resistance was exhibited. On the other hand, the cured product obtained by using the acid anhydride of Comparative Example 4-1 was tetrafunctional, but since the mother rib alcohol lacked rigidity, heat resistance was insufficient. Further, the cured product obtained by using the acid anhydride of Comparative Example 4-2 had a rigid trimeric isocyanate ring in the core, but the heat resistance was insufficient and the transparency was lacking.

Further, when the surface roughness of the cured products of Examples 4-1 to 7 was visually observed, since the acid anhydride of the present invention did not volatilize upon hardening, it was smooth. By the above-described characteristics of the acid anhydride of the present invention, it is expected that the cured product of the curable resin composition of the present invention is also excellent in dimensional stability.

Further, in Examples 4-4 to 6, since the transparency evaluated by visual observation was equal to or higher than that of Examples 4-1 to 3, the measurement of the haze was omitted.

Examples 5-1 to 5: Preparation of hardened material (glass cloth-epoxy composite sheet)

The curable resin composition of the present invention obtained in Example 3 was cured in the same manner as in Example 4 to obtain a cured product of the present invention. The obtained cured product was evaluated in the same manner as in Example 4.

From the above results, it is understood that the cured product obtained by using the acid anhydride of the present invention is excellent in heat resistance, toughness, and transparency. The cured products of Examples 5-1 to 4 using the acid anhydrides of Examples 1 to 4 were excellent in heat resistance and transparency because they had a rigid skeleton and a soft alkyl chain in the core. Using Examples 5 to 5 of the acid anhydrides of Examples 1 to 4, although some of the coloring of EOCN-103S used was observed, the heat resistance was excellent.

Although the present invention has been described in detail with reference to the specific embodiments thereof, it should be understood that

Further, the present application is based on a Japanese patent application filed on Aug. 18, 2016 (Japanese Patent Application No. 2016-160421), the entire contents of which is incorporated by reference. Moreover, the entire contents of all references in this document are incorporated.

 [Industrial availability]  

The acid anhydride of the present invention and the curable resin composition thereof are suitable for coatings and FRP for civil engineering, and are suitable for coatings, resist inks, adhesives, sealants, and encapsulants in the field of printed circuit boards/semiconductors. Electrical and electronic materials are mainly used for hardened materials used in display devices such as liquid crystal displays, plasma displays, EL displays, mobile devices, and solar cells.

Claims (15)

An acid anhydride which is an acid anhydride represented by the following general formula (1), In the formula, R ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 11 carbon atoms or a structure represented by the following formula (I); At least one of the substituents represents a substituent having a structure represented by the following formula (I); * indicates the bonding position. The acid anhydride according to the first aspect of the invention, wherein the substituent having the structure represented by the above formula (I) is a substituent represented by the following formula (II). In the formula, R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms, and ** represents a bond position. An acid anhydride obtained by reacting an alcohol (A) represented by the following formula (2) with a carboxylic acid halide (B), In the formula, R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ represents A hydrogen atom. The acid anhydride according to claim 3, wherein the carboxylic acid halide (B) is represented by the following formula (3). R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms. An acid anhydride obtained by reacting an alcohol (A) represented by the following formula (2) with one or more selected from the group consisting of alkylene oxides, cyclic ethers and cyclic esters to obtain an alcohol (C) And reacting the alcohol (C) with the carboxylic acid halide (B), In the formula, R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ represents A hydrogen atom). The acid anhydride according to claim 5, wherein the carboxylic acid halide (B) is represented by the following formula (3). R ⁵ represents a direct bond or a hydrocarbon group having 1 to 11 carbon atoms.  A thermosetting resin composition containing a compound having at least one epoxy group in one molecule, and an acid anhydride according to any one of claims 1 to 6.    The thermosetting resin composition according to claim 7, which further comprises particles (D-1) or fibers (D-2).    The thermosetting resin composition according to claim 8, wherein the particles (D-1) are inorganic particles.    The thermosetting resin composition according to claim 8, wherein the fiber (D-2) is a glass fiber.    The thermosetting resin composition according to claim 8, wherein the fiber (D-2) is a glass cloth obtained by spinning a glass fiber.    A thermosetting resin composition obtained by imparting a shape in a semi-hardened state to a thermosetting resin composition according to any one of claims 7 to 11.    A cured product obtained by curing the thermosetting resin composition according to any one of claims 7 to 12.   The method for producing an acid anhydride according to the first or third aspect of the invention, wherein the alcohol (A) represented by the following formula (2) is reacted with a carboxylic acid halide (B), In the formula, R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ represents A hydrogen atom. The method for producing an acid anhydride according to the fifth aspect of the invention, wherein the alcohol (A) represented by the following formula (2) and a group selected from the group consisting of alkylene oxides, cyclic ethers and cyclic esters are used. One or more of the reactions are carried out to obtain an alcohol (C), and the obtained alcohol (C) is reacted with a carboxylic acid halide (B). In the formula, R' ¹ , R' ² , R' ³ and R' ⁴ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, and at least one of R' ² , R' ³ and R' ⁴ represents A hydrogen atom.