JP4888027B2 - Curing agent for radical polymerization type thermosetting resin, molding material containing the same, and curing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curing agent for a radical polymerization type thermosetting resin capable of enhancing the curing rate of a radical polymerization type thermosetting resin and controlling the remnant of an unsaturated monomer, a molding material containing it, and a curing method for the resin. <P>SOLUTION: This curing agent for a radical polymerization type thermosetting resin contains t-alkylperoxyalkylate represented by general formula (1), wherein R represents a 2-5C linear or branched alkyl group, and R' represents 1-2C alkyl group. This molding material is one compounded with 0.1-5 pts.mass the t-alkylperoxyalkylate relative to 100 pts.mass radical polymerization type thermosetting resin. This sheet molding compound (SMC) and this bulk molding compound (BMC) are further compounded with a contraction reducing agent, a filler, a tackifier, a mold release agent, a polymerization inhibitor, and a reinforcing agent. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a curing agent for a radical polymerization type thermosetting resin used for curing a radical polymerization type thermosetting resin such as an unsaturated polyester resin, a molding material containing the same, and a curing method thereof.

  Conventionally, molding materials such as sheet molding compounds (hereinafter abbreviated as SMC) and bulk molding compounds (hereinafter abbreviated as BMC) used in the field of housing equipment such as bathtubs and wash units and the field of electrical components, etc. Are known. These SMCs and BMCs are radical polymerization type thermosetting resins such as unsaturated polyester resins and vinyl ester resins, curing agents, low shrinkage agents, fillers, thickeners, release agents, polymerization inhibitors, colorants, etc. Is a molding material in which a reinforcing material such as glass fiber is impregnated with a compound in which is mixed. Among them, the sheet-shaped molding material is SMC, and the bulk-shaped molding material is BMC.

  These molding materials are molded into fiber reinforced plastic (hereinafter abbreviated as FRP) by various molding methods such as compression molding, transfer molding, injection molding, and injection compression molding, and are used for housing equipment, automobile parts, It is widely used industrially as electrical parts, electronic parts and the like.

Since the molding material described above is usually heated and cured at 100 to 180 ° C., an organic peroxide that decomposes efficiently at such a temperature to generate radicals is used as a curing agent. As such organic peroxides, t-butyl peroxyacetate (see, for example, Patent Document 1) and t-butyl peroxybenzoate having a relatively good total balance with respect to various required performances have been widely used.
JP-A-9-31314 (pages 2 to 4)

  In recent years, the impact of VOC (volatile organic chemicals) contained in building materials on the human body has become a problem, especially in terms of sick house, sick school, sick building syndrome, etc., and the government seems to issue guidelines on building materials regarding VOCs. It has become. Therefore, it is said that reduction of VOCs such as styrene, which is a residual unsaturated monomer, is required for the preservation of the residential environment, even for cured products of radical polymerization type thermosetting resins used in building materials. There is a present situation.

  When the radical polymerization type thermosetting resin is cured with t-butyl peroxyacetate described in Patent Document 1, the thermal decomposition temperature is high, the curing rate is slow, and the curing is low because the polymerization efficiency of the generated radicals is low. There was a problem that the amount of unsaturated monomers remaining in the product increased. In addition, in the case of t-butyl peroxybenzoate, there is a problem that decomposition is slow due to the unique structure having a phenyl group, the curing rate is slow, and the amount of unsaturated monomer remaining in the cured product is large. was there.

  Therefore, the object of the present invention is to improve the curing rate of the radical polymerization type thermosetting resin and to suppress the residual of the unsaturated monomer for the radical polymerization type thermosetting resin. It is providing a hardening | curing agent, the molding material containing the same, and its hardening method.

  In order to achieve the above object, the curing agent for radical polymerization type thermosetting resin of the first invention in the present invention contains a t-alkyl peroxyalkylate represented by the following general formula (1). It is characterized by.

（但し、式中、Ｒは炭素数３の直鎖のアルキル基、Ｒ’は炭素数１のアルキル基を表す）
第２の発明の成形材料は、ラジカル重合型熱硬化性樹脂１００質量部に第１の発明のｔ−アルキルパーオキシアルキレート０．１〜５質量部を配合したことを特徴とするものである。

(Wherein, R represents an an alkyl group, R 'is an alkyl group of 1 to 4 carbon atoms, straight-chain having 3 carbon atoms)
The molding material of the second invention is characterized in that 0.1 to 5 parts by mass of the t-alkyl peroxyalkylate of the first invention is blended with 100 parts by mass of the radical polymerization type thermosetting resin. .

The molding material of the third invention is characterized in that in the second invention, a low shrinkage agent, a filler, a thickener, a mold release agent, a polymerization inhibitor and a reinforcing material are further blended.
A molding material according to a fourth invention is characterized in that, in the second or third invention, the radical polymerization type thermosetting resin is an unsaturated polyester resin.

  The molding material curing method of the fifth invention is characterized in that the molding material of any of the second to fourth inventions is cured at 100 to 180 ° C.

According to the present invention, the following effects can be exhibited.
The radical polymerization type thermosetting resin curing agent of the first invention contains a t-alkyl peroxyalkylate represented by the general formula (1). When this curing agent is used as a curing agent for a radical polymerization type thermosetting resin, the thermal decomposition temperature is lower than that of conventional t-butyl peroxyacetate, and t-butyl peroxyacetate or t-butyl peroxybenzoate. Due to the different chemical structure, decomposition starts at a low temperature to generate radicals, and the curing rate of the radical polymerization type thermosetting resin can be improved. Further, the radicals generated have high efficiency of radical polymerization reaction, and can suppress the remaining of unreacted unsaturated monomer.

  The molding material of 2nd invention mix | blends 0.1-5 mass parts of t-alkyl peroxyalkylates shown by General formula (1) in 100 mass parts of radical polymerization type thermosetting resins. For this reason, when the radical polymerization type thermosetting resin is cured, the effect of the first invention can be sufficiently exhibited.

  The molding material of the third invention is obtained by further blending the molding material of the second invention with a low shrinkage agent, a filler, a thickener, a release agent, a polymerization inhibitor and a reinforcing material. Therefore, in addition to the effects of the second invention, it is suitable as a molding material for SMC or BMC.

  In the molding material of the fourth invention, the radical polymerization type thermosetting resin in the second or third molding material is an unsaturated polyester resin. This molding material has high storage stability at room temperature and little change in the curing characteristic value. Further, when heated, a molded product that has a small amount of volatile organic compounds (VOC) such as styrene and can be suitably used for building materials can be obtained in a short time.

  In the molding material curing method of the fifth invention, the molding material of any of the second to fourth inventions is cured at 100 to 180 ° C., so that the curing reaction can be easily performed. The effect of any one of the inventions of 4 can be exhibited.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
The curing agent for radical polymerization type thermosetting resin of the present embodiment contains a t-alkyl peroxyalkylate represented by the following general formula (1).

（但し、式中、Ｒは炭素数３の直鎖のアルキル基、Ｒ’は炭素数１のアルキル基を表す）
一般式（１）中のＲのうち、炭素数３の直鎖のアルキル基としては、プロピル基が挙げられる。一般式（１）中のＲが炭素数１のｔ−ブチルパーオキシアセテートの場合には、熱分解温度が高いためにラジカル重合型熱硬化性樹脂（以下、単に熱硬化性樹脂ともいう）の硬化速度が遅く、また生成するラジカルの重合効率が悪いために得られる硬化物に残存する不飽和単量体が多くなる。一方、Ｒが炭素数６を越える場合には、活性酸素量が低下するため、これを含有する熱硬化性樹脂の硬化が遅くなると共に、硬化物中の不飽和単量体が多くなる。

(Wherein, R represents an an alkyl group, R 'is an alkyl group of 1 to 4 carbon atoms, straight-chain having 3 carbon atoms)
Of R in the general formula (1), examples of the straight chain alkyl group having 3 carbon atoms, and a flop propyl group. One if general formula (1) R in is a t- butyl peroxy acetate 1 carbon atoms, a radical polymerization type thermosetting resin in the thermal decomposition temperature is high (hereinafter, simply referred to as a thermosetting resin) The curing rate of the polymer is slow and the polymerization efficiency of the radicals generated is low, so that the amount of unsaturated monomer remaining in the resulting cured product increases. On the other hand, when R exceeds 6 carbon atoms, the amount of active oxygen decreases, so the curing of the thermosetting resin containing it slows down and the unsaturated monomer in the cured product increases.

  Of R ′ in the general formula (1), the alkyl group having 1 or 2 carbon atoms is a methyl group or an ethyl group. When this R 'exceeds 2 carbon atoms, the polymerization efficiency is poor and the time until the curing is completed is long, and the amount of unsaturated monomer remaining in the resulting cured product increases.

Therefore, the specific t-alkyl peroxyalkylate in which R is a straight- chain alkyl group having 3 carbon atoms and R ′ is 1 carbon atom improves the curing rate of the thermosetting resin and increases the unsaturated monomer. It is an excellent curing agent that can exhibit the effect of suppressing the residual of the resin in a well-balanced manner.

Specific examples of the t- alkyl peroxy alkylate represented by the general formula (1) may, t - hexyl peroxy acetate tape and.

Among these, t-hexyl peroxyacetate is particularly preferable. The reason for this is that t-hexyl peroxyacetate (10-hour half-life temperature 98.3 ° C.) has a lower thermal decomposition temperature than t-amyl peroxyacetate (10-hour half-life temperature 99.6 ° C.), so that curing is possible. Fast (short T ₉₀ for curing characteristics), can shorten the demoldable time, and because the polymerization efficiency of the generated radicals is high, the unsaturated monomer in the cured product can be reduced from t-amyl peroxyacetate. is there. Moreover, t-hexylperoxyacetate has a higher thermal decomposition temperature than 1,1-dimethylpentylperoxyacetate and 1,1,3,3-tetramethylbutylperoxyacetate (10 hour half-life temperature 90.0 ° C.). Because it is difficult to thermally decompose, the amount of the polymerization inhibitor added to adjust the flow time in the mold can be reduced, and coloring of the cured product derived from the polymerization inhibitor can be suppressed. This is because the problem of coloring in the case of obtaining does not occur. In addition, t-hexylperoxyacetate has higher polymerization efficiency of the radicals produced than t-hexylperoxypropionate, so the unsaturated monomer in the cured product is reduced compared to t-hexylperoxypropionate. it can. Here, the 10-hour half-life temperature is the decomposition temperature at which the half-life of the organic peroxide is reached in 10 hours when the organic peroxide 0.1 mol / liter cumene solution is thermally decomposed. .

  The t-alkyl peroxyalkylate having a specific structure represented by the general formula (1) can be produced according to a known production method. For example, t-hexyl peroxyacetate can be produced by reacting t-hexyl hydroperoxide with acetyl chloride or acetic anhydride.

  The t-alkyl peroxyalkylate is preferably used as a peroxide composition diluted with a diluent in order to enhance its handleability. Examples of the diluent include aliphatic hydrocarbons, aromatic hydrocarbons, acetic acid esters, pivalic acid esters, adipic acid esters, neodecanoic acid esters, glutaric acid esters, succinic acid esters, adipic acid esters, maleic acid esters, Fumaric acid ester, benzoic acid ester, phthalic acid ester, phosphoric acid ester, ketone, alcohol, alkylene glycol, polyalkylene glycol, alkylene glycol monoalkyl ether, dialkylene glycol monoalkyl ether, alkylene glycol monoalkyl ether acetate, etc. Any material can be used as long as it does not adversely affect the stability of the alkyl peroxyacetate, the curing characteristics of the molding material and the physical properties of the cured product. The usage-amount of the diluent which concerns is normally 50 mass parts or less with respect to 100 mass parts of hardening | curing agents for thermosetting resins. These diluents can be added at any time during or after the production of the t-alkyl peroxyalkylate.

  In the curing agent, together with the t-alkyl peroxyalkylate represented by the general formula (1), for example, to improve curing characteristics and degree of curing in low temperature molding near 100 ° C. or high temperature molding near 180 ° C. In addition, other known organic peroxides having different thermal decomposition temperatures can be used in combination. In that case, in order for the t-alkyl peroxyalkylate represented by the general formula (1) to fully express its function, the t-alkylperoxyalkylate is 50% by mass as an organic peroxide in the curing agent. It is preferable to mix | blend so that the above may be occupied. As other known organic peroxides, for example, 1,1-di (t-butylperoxy) cyclohexane, 1,1-di (t-amylperoxy) cyclohexane, 1,1-di (t-hexylperoxy) ) Cyclohexane, 1,1-di (t-hexylperoxy) -3,5,5-trimethylcyclohexane, 2,2-di (t-butylperoxy) butane, n-butyl 4,4-di- (t -Butylperoxy) valerate, peroxyketals such as 2,2-di (4,4-di (t-butylperoxy) cyclohexyl) propane, diacyl peroxides such as dilauroyl peroxide, dibenzoyl peroxide, di Peroxydicarbonates such as (4-t-butylcyclohexyl) peroxydicarbonate, t-butylperoxy-2-ethylhexa Ate, t-amylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t -Butylperoxybenzoate, t-amylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxyisobutyrate, t-butylperoxymaleate, t-butylperoxy-3,5,5-trimethyl Peroxyesters such as hexanoate and t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-amyl peroxyisopropyl monocarbonate, t-hexyl peroxyisopropyl monocarbonate, 1,1,3 3-tetramethylbutylperoxyiso Propyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, t-amylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxy-2-ethylhexyl monocarbonate, 1,6-bis (t-butyl Peroxycarbonyloxy) peroxymonocarbonate such as hexane.

  Next, a molding material containing the t-alkyl peroxyalkylate represented by the general formula (1) and a radical polymerization type thermosetting resin (hereinafter also simply referred to as a thermosetting resin) will be described.

  Thermosetting resins are usually unsaturated polyester resins, vinyl ester resins, and (meth) acrylic resins, and can be used alone or in combination. Unsaturated polyester resin, unsaturated dibasic acid, saturated dibasic acid and polyhydric alcohol are heated and dehydrated and condensed at a specific ratio, and the unsaturated polyester obtained by esterification is converted into a radical polymerizable unsaturated monomer (hereinafter, It is a liquid resin obtained by dissolving in an abbreviated unsaturated monomer.) Any known resin can be used.

  Examples of the unsaturated dibasic acid include maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid and the like, and one or more of these groups are selected and used. Examples of the saturated dibasic acid include aromatic dibasic acids such as phthalic anhydride, orthophthalic acid, isophthalic acid, and terephthalic acid, and aliphatic dibasic acids such as adipic acid, succinic acid, and sebacic acid. One or more of the groups are selected and used. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, bisphenol A, hydrogenated bisphenol A, and hydrogenated bisphenol A. Of ethylene oxide or propylene oxide, and one or more of these groups are selected and used.

Examples of the unsaturated monomer include styrene derivatives such as styrene, vinyl toluene, α-methyl styrene, t-butyl styrene, chlorostyrene, dichlorostyrene, and divinylbenzene. In addition, in order to reduce the amount of residual styrene in the resulting cured product, monomethyl fumarate, dimethyl fumarate, monoethyl fumarate, diethyl fumarate, monopropyl fumarate, dipropyl fumarate, monobutyl fumarate, dibutyl fumarate Α, such as rate, monooctyl fumarate, dioctyl fumarate, monomethyl maleate, dimethyl maleate, monoethyl maleate, diethyl maleate, monopropyl maleate, dipropyl maleate, monobutyl maleate, dibutyl maleate β-unsaturated polybasic acid alkyl, diallyl phthalate, N-vinyl pyrrolidone, vinyl acetate such as vinyl acetate, vinyl propionate, vinyl (meth) acrylate, vinyl crotonate, allyl (meth) acrylate, methyl (meta Acu Rate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, cyclohexyl (meth) acrylate, Benzyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, decyl (meth) acrylate, tricyclo [5 · 2 · 1 · 0 ^2,6 ] decanyl (meth) acrylate, lauryl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, steer Alkyl (meth) acrylates such as ril (meth) acrylate, hebenyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , Hydroxypropyl (meth) acrylate, 2-hydroxy-1-methylethyl (meth) acrylate, 1-ethyl-2-hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene Glycol mono (meth) acrylate, polyethylene glycol-polypropylene glycol mono (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) Hydroxyl-terminated (poly) alkylene glycol mono (meth) acrylate such as (meth) acrylate, poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, Methoxytetraethylene glycol (meth) acrylate, 2-phenoxyethyl (meth) acrylate, cyclohexyloxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, phenoxy Diethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, Lauroxy poly Tylene glycol mono (meth) acrylate, stearoxy polyethylene glycol mono (meth) acrylate, nonylphenoxy polyethylene glycol mono (meth) acrylate, allyloxy polyethylene glycol-polypropylene glycol mono (meth) acrylate, octoxy polyethylene glycol-polypropylene glycol mono ( End of alkyl group such as (meth) acrylate, stearoxy polyethylene glycol-polypropylene glycol mono (meth) acrylate, nonylphenoxy polyethylene glycol-polypropylene glycol mono (meth) acrylate, nonylphenoxy (polyethylene glycol-polypropylene glycol) mono (meth) acrylate ( Poly) alkylene glycol mono (meth) acryl Rate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate , Polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, poly (ethylene glycol-tetramethylene glycol) di (meth) acrylate, poly (propylene glycol-tetramethylene glycol) di (meth) acrylate, polyethylene Glycol-polypropylene glycol-polyethylene glycol di (meth) acrylate, 1,4-tetramethylene glycol di (meth) Acrylate, 1,6-hexanediol-di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,9-nonanediol-di (meth) acrylate, ethylene oxide modified bisphenol A di (meth) acrylate, propylene oxide (Poly) alkylene glycol di (meth) acrylates such as modified bisphenol A di (meth) acrylate, ethylene oxide-propylene oxide modified bisphenol A di (meth) acrylate, propylene oxide-tetramethylene oxide modified bisphenol A di (meth) acrylate, Trimethylolethane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethyl (Meth) having three or more (meth) acryloyl groups in the molecule such as ethane ethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Acrylate, glycidyl (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, (meth) acryloyl oxyethyl phthalate, (meth) acryloyloxysuccinate, 2- (meth) acryloyloxyethyl maleate, 2 -Hydroxy-3-acryloyloxypropyl (meth) acrylate, oligoester (meth) acrylate, urethane (meth) acrylate oligomer, oleic acid modified glycidyl (meth) a Chryrate, soybean oil fatty acid modified glycidyl (meth) acrylate, zinc mono (meth) acrylate, zinc di (meth) acrylate, (meth) acrylate, (meth) acrylate, N, N, N-trimethyl-N- (2-hydroxy-3 -(Meth) acrylic acid such as (meth) acryloyloxypropyl) ammonium chloride, and (meth) acrylic acid alkyl esters. In addition, (meth) acrylate or (meth) acrylic acid ester means a general term for acrylate (acrylic acid ester) and methacrylate (methacrylic acid ester). One or more of these unsaturated monomers can be used alone or in combination with a styrene derivative.

  And the preferable structural ratio of unsaturated polyester which is a structural component of unsaturated polyester resin, and an unsaturated monomer is 30-80 mass% of unsaturated polyester, and 70-20 mass% of unsaturated monomers. is there. When the unsaturated polyester is less than 30% by mass and the unsaturated monomer exceeds 70% by mass, the mechanical properties of the cured product of the obtained unsaturated polyester resin tend to deteriorate. On the other hand, when the unsaturated polyester exceeds 80% by mass and the unsaturated monomer is less than 20% by mass, the resulting unsaturated polyester resin has a high viscosity and tends to deteriorate workability.

  On the other hand, the vinyl ester resin is also referred to as an unsaturated epoxy resin or an epoxy acrylate resin, and an unsaturated group such as acrylic acid or methacrylic acid is added to an epoxy group of an epoxy resin having two or more epoxy groups in one molecule. It is obtained by dissolving a reaction product (hereinafter abbreviated as epoxy acrylate) obtained by ring-opening addition of monobasic acid or monoester of unsaturated dibasic acid such as maleic acid or fumaric acid in unsaturated monomer. Any known resin can be used.

  As the epoxy resin, any of known epoxy resins can be used. Specifically, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin synthesized from bisphenol A, bisphenol F or bisphenol S and epichlorohydrin, or Bisphenol type epoxy resin such as bisphenol S type epoxy resin, so-called phenol novolac resin obtained by reacting phenol and formaldehyde in the presence of acidic catalyst and epichlorohydrin, and phenol novolac type epoxy resin and cresol and formaldehyde are present as acidic catalyst Novolak type epoxy such as cresol novolak type epoxy resin synthesized from so-called cresol novolak resin and epichlorohydrin obtained by reaction under Butter, and the like can be mentioned. As the unsaturated monomer, any of the unsaturated monomers similar to the unsaturated monomer in the unsaturated polyester resin described above can be used, and one or more of these groups are selected and used. The

  And as for the preferable structural ratio of the epoxy acrylate which is a structural component of vinyl ester resin, and an unsaturated monomer, an epoxy acrylate is 30-90 mass%, and an unsaturated monomer is 70-10 mass%. When the epoxy acrylate is less than 30% by mass and the unsaturated monomer exceeds 70% by mass, the corrosion resistance and heat resistance of the resulting vinyl ester resin cured product tend to deteriorate. On the other hand, when the epoxy acrylate exceeds 90% by mass and the unsaturated monomer is less than 10% by mass, the resulting vinyl ester resin has a high viscosity and tends to deteriorate workability.

  The (meth) acrylic resin is obtained by dissolving a (meth) acrylic resin in an unsaturated monomer having a cross-linking agent having two or more radically polymerizable unsaturated groups in one molecule as an essential component. It refers to (meth) acrylic syrup, and any known one can be used. The (meth) acrylic resin is obtained by polymerizing a (meth) acrylic ester with an organic peroxide or an azo compound. Here, as (meth) acrylic acid ester, alkyl (meth) acrylate, hydroxyl-terminated (poly) alkylene glycol mono (meth) acrylate, alkyl-terminated (poly) alkylene glycol mono (meth) in the aforementioned unsaturated polyester resin (Meth) acrylic acid esters similar to acrylates and the like can be used.

  These (meth) acrylic acid esters may be used alone or in combination of two or more. In order to obtain a cured product having excellent weather resistance, transparency, and surface gloss, 50% by mass or more of methyl methacrylate is contained. It is preferable. When thermoforming above the boiling point of methyl methacrylate, high-boiling point (meth) acrylic having methyl methacrylate and cyclohexane ring, bicyclo ring, tricyclo ring and other groups to improve hot water resistance with less uneven gloss of the cured product It is preferable to use an acid ester in combination.

  In addition, as a constituent of (meth) acrylic resin, unsaturated monobasic acid such as (meth) acrylic acid and crotonic acid, unsaturated dibasic acid in unsaturated polyester resin, monoester of unsaturated dibasic acid, styrene Derivatives and vinyl esters can be contained in a proportion of 30% by mass or less.

  As said unsaturated monomer which is a structural component of (meth) acrylic resin, in addition to the (meth) acrylic acid ester which is a structural component of said (meth) acrylic resin, the above-mentioned unsaturated monobasic acid and unsaturated Examples include dibasic acids, monoesters of unsaturated dibasic acids, styrene derivatives, and vinyl esters. These unsaturated monomers may be used alone or in combination of two or more, but preferably contain 50% by mass or more of methyl methacrylate. By containing 50% by mass or more of methyl methacrylate, a cured product having excellent weather resistance, transparency, and surface gloss can be obtained.

  This unsaturated monomer contains a monomer having two or more radically polymerizable unsaturated groups in one molecule, a so-called crosslinking agent as an essential component. Examples of the crosslinking agent include (poly) alkylene glycol di (meth) acrylate in the unsaturated polyester resin, (meth) acrylate having three or more (meth) acryloyl groups in the molecule, vinyl esters, divinylbenzene, and the like. And diallyl phthalate. One or two or more of these crosslinking agents are selected and used. The content of the crosslinking agent in the unsaturated monomer is preferably 1 to 20% by mass, more preferably 3 to 15% by mass. When content of a crosslinking agent is less than 1 mass%, it exists in the tendency for the heat resistance of the hardened | cured material obtained to deteriorate. On the other hand, when the content of the crosslinking agent exceeds 20% by mass, the obtained cured product tends to be brittle.

  The preferable composition ratio of the (meth) acrylic resin and the unsaturated monomer, which is a constituent of the (meth) acrylic resin composition, is 10 to 50% by mass of the (meth) acrylic resin, and the unsaturated monomer is It is 90-50 mass%. When the (meth) acrylic resin is less than 10% by mass and the unsaturated monomer exceeds 90% by mass, the resulting cured product is easily cracked. On the other hand, when the (meth) acrylic resin exceeds 50% by mass and the unsaturated monomer is less than 50% by mass, the viscosity increases and the workability tends to deteriorate.

  The content of the t-alkyl peroxyalkylate represented by the general formula (1) in the molding material varies depending on the molding temperature, desired molding time, etc., but is preferably pure with respect to 100 parts by mass of the thermosetting resin. The amount is 0.1 to 5 parts by mass, and more preferably 0.5 to 4 parts by mass. When the content is pure and less than 0.1 parts by mass with respect to 100 parts by mass of the thermosetting resin, the curing time tends to be long and the curing tends to be insufficient. On the other hand, when the content exceeds 5 parts by mass with respect to 100 parts by mass of the thermosetting resin, the effect of increasing the amount is not seen, and the curing agent is wasted and is not practical. In some cases, the decomposition residue of the curing agent causes a problem in appearance such as coloring the molded product, which is not preferable.

  In addition to the thermosetting resin and the curing agent represented by the general formula (1), the molding material contains a low shrinkage agent, a filler, a thickener, a release agent, a polymerization inhibitor and a reinforcing material. Although it is general, at least one component may be excluded depending on the purpose. For example, when a low shrinkage type thermosetting resin is used as the thermosetting resin, the low shrinkage agent can be excluded. Moreover, a coloring material, a pattern material, a decorating base material, and a drainage improvement agent can also be contained in a molding material as needed. Furthermore, known additives used in the field of molding materials, such as ultraviolet absorbers, anti-separation agents, thickening regulators, antifoaming agents, antistatic agents, flame retardants, lubricants, water repellents, etc., depending on the application It can be included.

  The low shrinkage agent is a component that suppresses the curing shrinkage of the thermosetting resin, increases the dimensional accuracy of the cured product (molded product), and enhances surface characteristics such as surface glossiness and smoothness. Examples of the low shrinkage agent include thermoplastic resins such as polystyrene, polyethylene, polyvinyl acetate, polymethyl methacrylate, crosslinked polystyrene, saturated polyester, polycaprolactone, and styrene-vinyl acetate block copolymer, and rubbers such as butadiene rubber. And thermoplastic elastomers such as a styrene-butadiene block copolymer, a styrene-butadiene-styrene block, or a graft copolymer. These low shrinkage agents may be blended singly or in combination of two or more. When two or more types are used in combination, low shrinkage and surface properties, as well as mechanical properties, colorability, transparency, hot water resistance, or a thermoplastic resin such as polystyrene and styrene-vinyl acetate block By using the combination, the separation stability between the thermosetting resin and the thermoplastic resin can be increased. The blending amount of the low shrinkage agent is preferably 3 to 30 parts by mass with respect to 100 parts by mass of the thermosetting resin. The low shrinkage agent can also be blended as a solution dissolved in a monomer such as styrene.

  The filler (filler) is a component for improving the fluidity of a molding material, improving the rigidity of a cured product, reducing shrinkage, improving transparency, improving surface glossiness and smoothness, and reducing weight. Such fillers include calcium carbonate, aluminum hydroxide, magnesium hydroxide, barium sulfate, clay, silica, talc, glass frit, glass balloon, glass microballoon, shirasu balloon, and other inorganic fillers, synthetic fibers, and natural fibers. And organic fillers such as As the filler, those subjected to surface treatment with a silane coupling agent or the like can also be used. The blending amount of the filler is preferably 50 to 300 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  The thickener is a component for increasing the viscosity of the molding material and facilitating the impregnation of the reinforcing material. Examples of the thickener include oxides or hydroxides of alkaline earth metals such as magnesium oxide, calcium oxide, zinc oxide, magnesium hydroxide, and calcium hydroxide, and polymer powder. The blending amount of the thickener is preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. The mold release agent is a component for facilitating release of the molded product from the mold. Examples of the release agent include internal release agents such as zinc stearate, calcium stearate, stearic acid, and alkyl phosphate esters. The compounding amount of the release agent is preferably 1 to 8 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  The polymerization inhibitor is a component for suppressing polymerization at a stage before the molding material is polymerized. Such polymerization inhibitors include p-benzoquinone, hydroquinone, toluhydroquinone, t-butylhydroquinone, 1,4-naphthoquinone, trimethylhydroquinone, hydroquinone monomethyl ether, t-butylcatechol, 2,6-di-t-butyl-4 -Methylphenol, phenothiazines, N-oxyl compounds such as 4-hydroxy-2,2,6,6-tetrapiperidine-1-oxyl, ionic inorganic metals, phosphites and the like. The blending amount depends on the molding temperature and the desired flow time in the mold (when the molding material is heat-cured, the time during which the uncured molding material placed in the mold can flow in the mold without gelling) and molding. Although it varies depending on the time, the kind of polymerization inhibitor, the coloring degree of the molded product, and the like, it is usually 100 to 2000 ppm with respect to the thermosetting resin.

  The reinforcing material is a component for improving mechanical strength such as tensile strength, bending strength, impact strength, pressure strength, etc., and suppressing the occurrence of cracks, etc., in a molded product obtained from a molding material. Examples of the reinforcing material include inorganic fibers such as glass fibers and boron fibers, and organic fibers such as carbon fibers, aramid fibers, nylon fibers, acrylic fibers, polyester fibers, and vinylon fibers. Examples of the form of the reinforcing material include chopped strands having a length of 1 to 30 mm, chopped strand mats, roving cloths, glass cloths, filament mats, continuous mats, and non-woven fabrics. Select and use. The compounding quantity of a reinforcing material is 10-70 mass parts normally with respect to 100 mass parts of thermosetting resins. Examples of the colorant include inorganic pigments such as titanium white and carbon black, and organic dyes. The blending amount is preferably 1 to 10 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  The said pattern material and a decorating base material are components for adding a pattern, a pattern, and the texture of a marble to the molded article obtained by mix | blending with a molding material and shape | molding, and improving the designability. Pattern materials include natural stones, artificial stones, other inorganic substances, metals, colored thermoplastic resins and pulverized products such as fully cured products of thermosetting resins or semi-gel cured products, and plastic films on which patterns are printed or colored And the like. The blending amount is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the thermosetting resin. Examples of the decorative base material include fiber aggregates such as paper, woven fabric, non-woven fabric, glass mat, and glass cloth decorated by printing, coloring, etc., porous synthetic resin sheets, thermoplastic resin sheets, and the like. It is done. The decorative substrate may be disposed inside the SMC, or may be disposed in place of the SMC film. Moreover, it mounts on a metal mold | die so that it may be located on the surface of a molded article, SMC prepared separately may be mounted on it, and pressure molding may be carried out simultaneously.

  The drainage improver is a component that enhances drainage for shortening the time required for drainage and drying when a molded product obtained from a molding material is used as a floor panel of a bathtub or a decorative plate for a sink. Such drainage improvers include pyrrolidones such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, surfactants such as nonionic surfactants, anionic surfactants, and cationic surfactants. , Hydrophilic polymer compounds such as polyvinyl alcohol, polyvinyl pyrrolidone and polyacrylate, fluorine or non-fluorinated silicate compounds, polymers containing at least one of carboxylic acid group and fluoroalkyl group, and the like. The blending amount is preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  And the said tert-alkyl peroxyalkylate is mixed with a thermosetting resin as a hardening | curing agent, and a molding material is obtained. A compound can be obtained by further mixing the above-mentioned low shrinkage agent, filler, thickener, mold release agent and polymerization inhibitor, and a colorant as required. SMC can be manufactured by impregnating the reinforcing material with a reinforcing material by a manual operation or an SMC manufacturing apparatus or the like and then sandwiching the reinforcing material into a sheet shape. This SMC is usually thickened to a desired viscosity by aging over several hours to 2 days in the temperature range from room temperature to 40 ° C. In addition, the above-mentioned t-alkyl peroxyalkylate is mixed as a curing agent with a thermosetting resin, and further using a kneader such as a kneader, the above-described low shrinkage agent, filler, thickener, release agent, polymerization agent. BMC can be produced by mixing an inhibitor, a colorant and a reinforcing material.

  Next, the method for curing a molding material such as SMC or BMC can be produced by heating and curing the molding material at a curing temperature of 100 to 180 ° C. When the curing temperature is less than 100 ° C., the curing rate of the molding material is slow and the curing time tends to be long. On the other hand, when it exceeds 180 ° C., the in-mold fluidity of the molding material tends to deteriorate. As a specific curing method, a known molding method such as a compression molding method using a mold pre-heated to 100 to 180 ° C. or an electroforming mold, a transfer molding method, an injection molding method, an injection compression molding method, or the like is employed. The curing time varies depending on the curing temperature, the thickness of the target molded product, and the like, but is usually 1 to 15 minutes.

  Now, the operation of this embodiment will be described. When a curing agent containing a t-alkylperoxyalkylate represented by the general formula (1) is used as a curing agent for a thermosetting resin, t- Alkylperoxyalkylates are decomposed to generate radicals. At this time, t-alkyl peroxyalkylate has a lower thermal decomposition temperature than conventional t-butyl peroxyacetate, and has a radical chemical structure different from t-butyl peroxyacetate and t-butyl peroxybenzoate. Based on high radical activity. Therefore, it is easy to generate unsaturated monomer radicals based on radicals derived from the curing agent, the unsaturated monomer radicals grow, polymerization of the unsaturated monomers proceeds sufficiently, and radical polymerization type Curing of the thermosetting resin is promoted.

The effects exhibited by the above embodiment will be described collectively below.
-The thermosetting resin curing agent of this embodiment contains the t-alkyl peroxyalkylate represented by the general formula (1). When this curing agent is used as a curing agent for a thermosetting resin, decomposition starts at a low temperature to generate radicals, and the curing rate of the thermosetting resin can be increased. Further, the radicals generated have high efficiency of radical polymerization reaction, and can suppress the remaining of unreacted unsaturated monomer. Therefore, at the time of molding, the heating time can be shortened, and the demoldable time for taking out the cured product from the mold can be shortened, so that the productivity can be improved.

  -As a molding material, by blending 0.1 to 5 parts by mass of the t-alkyl peroxyalkylate represented by the general formula (1) with 100 parts by mass of the thermosetting resin, when the thermosetting resin is cured, The effect of can be fully exhibited.

  ・ As a molding material, by further blending a low shrinkage agent, filler, thickener, mold release agent, polymerization inhibitor and reinforcing material, the molding material is suitable as a molding material for SMC or BMC. It is.

  ・ Molding material whose radical polymerization type thermosetting resin is unsaturated polyester resin has high storage stability at room temperature, little change in curing characteristic value, and less VOC such as styrene by heating. A molded product that can be suitably used can be obtained by molding in a short time.

-As a curing method of the molding material, the curing reaction can be easily performed by curing the molding material at 100 to 180 ° C.
-Therefore, cured products obtained by curing molding materials (SMC, BMC, etc.) are suitably used as components for housing equipment such as bathtubs and washstands, automobile rear spoilers, water tank panels, electrical components, electronic components, etc. can do.

Hereinafter, the embodiment will be described more specifically with reference examples, examples, and comparative examples. In these examples,% and part represent mass% and mass part, respectively. Moreover, the abbreviations of the curing agents used in Reference Examples, Examples and Comparative Examples are shown below.

TBPA (t-butyl peroxyacetate, purity: 50.1%, active oxygen content: 6.14%)
TBPL (t-butyl peroxylaurate, purity: 99.1%, active oxygen content: 5.83%)
TAPA (t-amyl peroxyacetate, purity: 93.3%, active oxygen content: 10.3%)
THPA (t-hexyl peroxyacetate, purity: 90.3%, active oxygen content: 9.03%)
THPP (t-hexyl peroxypropionate, purity: 95.5%, active oxygen content: 8.81%)
THPH (t-hexylperoxyhexanoate, purity: 95.7%, active oxygen content: 7.09%)
TMBPA (1,1,3,3-tetramethylbutyl peroxyacetate, purity 91.9%, active oxygen content: 7.82%)
CPA (cumyl peroxyacetate, purity: 80.5%, active oxygen content: 6.65%)
TBPB (t-butyl peroxybenzoate, purity: 99.3%, active oxygen content: 8.20%)
THPB (t-hexyl peroxybenzoate, purity: 93.1%, active oxygen content: 6.71%)
TBP355 (t-butylperoxy 3,5,5-trimethylhexanoate, purity: 98.8%, active oxygen content: 6.87%)
THP355 (t-hexylperoxy 3,5,5-trimethylhexanoate, purity: 91.5%, active oxygen content: 5.67%)
THPC (1,1-di (t-hexylperoxy) cyclohexane, purity: 91.1%, active oxygen content: 9.22%)
TBIC (t-butylperoxyisopropyl monocarbonate, purity: 98.9%, active oxygen content: 8.9%)
Further, the curing characteristics of the molding material, the amount of residual styrene in the cured product, and the color of the cured product were measured by the following methods.
1) Curing characteristics Curing test is performed using a curast meter (Nissho Shoji Co., Ltd. JSR curast meter V type, amplitude angle ± 1/4 °), and the change in torque (N · m) during the curing process is measured. It was measured. The time from the start of measurement until torque is expressed (hereinafter, abbreviated as T _0), the maximum torque (hereinafter, abbreviated as MH) time to 10% is obtained (hereinafter, abbreviated as T ₁₀₎ , and 90% the time to obtain the MH _(hereinafter abbreviated as _{T 90)} were measured. Note that T ₀ is an index of the moldable flow time, T ₉₀ -T ₁₀ is an index of the rise time of curing, and T ₉₀ is an index of the mold release possible time.
2) Change rate of curing characteristic The curing property of a sheet-like molding material left in a thermostatic bath at 25 ° C. for 2 and 4 weeks was obtained, and the change rate of the characteristic value was obtained by the following formula.

Change rate of characteristic value = [(initial value−measured value) / initial value] × 100 (%)
And represents the rate of change of _{T 0} the rate of change [Delta] T _{0, T 90} as [Delta] T _90. When the change rate of the characteristic value is a positive value, the curing is fast, and when the characteristic value is a negative value, the curing is slow.
3) Press molding After the molding material is placed in a 150 mm long, 100 mm wide and 3 mm high mold preheated to a lower mold of 145 ° C and an upper mold of 130 ° C, the cured product is formed by press molding at a pressure of 10 MPa for 5 minutes. Manufactured.
4) Residual styrene content The cured product obtained with a curastometer or the cured product obtained by press molding is pulverized by a pulverizer, and about 3 g of sample is collected in a 50 ml (milliliter) glass conical flask with a stopper. did. Subsequently, 20 ml of methylene chloride was left as an extraction solvent at 25 ° C. for 24 hours to extract styrene remaining in the ground sample. Thereafter, the residual styrene content (%) in the cured product was measured by gas chromatography using n-decane as an internal standard.
5) Color of cured product The b value of the cured product obtained by press molding was determined using a color meter [color meter CR-241 manufactured by Konica Minolta Holdings, Inc.]. Next, the b value after the cured product was immersed in warm water at 95 ° C. for 500 hours using a boiling resistance test apparatus was similarly evaluated. The b value means that the higher the numerical value, the higher the degree of yellow, and the lower the numerical value, the higher the degree of blue.
( Reference Example 1 , Example 2, Reference Example 3 and Reference Example 4)
Unsaturated polyester resin (Japan Composite Co., Ltd., trade name: Polyhop 6370, styrene content 43.1%) 100 parts in a 500 ml polyethylene container, calcium carbonate (manufactured by Nitto Flour Industry Co., Ltd., product) Name: NS # 100) 150 parts. Subsequently, the t-alkyl peroxyalkylate of the present invention (TAPA, THPA, TMBPA, THPP) was added as a curing agent in an amount of 1 part each in terms of pure organic peroxide. In the characteristic evaluation using a curastometer, 150 parts of calcium carbonate was blended in order to prevent variation in measurement due to mold separation from the mold due to curing shrinkage. Subsequently, the compound was obtained by mixing with a stirrer. The compound was cured at an upper mold of 145 ° C. and a lower mold of 130 ° C. using a curast meter, and the residual styrene content of the cured product taken out 2.5 minutes after clamping was measured. The results are shown in Table 1.
(Examples 5-7)
0.5 part pure t-hexyl peroxyacetate (THPA) of the present invention as a curing agent and peroxyketal (THPC), peroxymonocarbonate (TBIC) or peroxyester (TBPB) as a known curing agent ) Was added in the same manner as in Examples 1 to 4 except that an amount of 0.5 parts in pure content was added, and the curing characteristics and the amount of residual styrene of the obtained cured product were measured. The results are shown in Table 1.
(Comparative Examples 1-8)
Other than the present invention as a curing agent, t-alkyl peroxyacetate (TBPA, CPA) in which R is an alkyl group bonded with an alkyl group having 1 carbon atom or a phenyl group having 9 carbon atoms, R ′ is a primary carbon atom T-hexyl peroxyalkylate (TBPH) which is an alkyl group, t-alkylperoxyalkylate where R is a primary alkyl group having 1 carbon atom and R ′ is 11 carbon atoms, or t-alkylperoxyester ( Except for using TBPB, THPB, TBP355, and THP355), a molding material was prepared in the same manner as in Reference Example 1, and the curing characteristics and the amount of residual styrene in the obtained cured product were measured. The results are shown in Table 1.

表１に示した結果から、参考例１、実施例２、参考例３及び参考例４のｔ−アルキルパーオキシアルキレート（ＴＡＰＡ、ＴＨＰＡ、ＴＭＢＰＡ及びＴＨＰＰ）を硬化剤として使用した場合、比較例１及び２のｔ−アルキルパーオキシアセテート（ＴＢＰＡ、ＣＰＡ）、比較例３のｔ−ヘキシルパーオキシアルキレート（ＴＨＰＨ）及び比較例４のｔ−アルキルパーオキシアルキレートよりも硬化物の残存スチレン量が少なくなることが明らかになった。また、比較例５及び６のＴＢＰＢやＴＨＰＢで示されたｔ−アルキルパーオキシベンゾエートや、比較例７及び８のＴＢＰ３５５及びＴＨＰ３５５で示されたＲ’が分岐アルキル基であるｔ−アルキルパーオキシアルキレートでは、残存スチレン量の少ない硬化物を得ることができなかった。

From the results shown in Table 1, when the t-alkyl peroxyalkylates (TAPA, THPA, TMBPA and THPP) of Reference Example 1 , Example 2, Reference Example 3 and Reference Example 4 were used as curing agents, Comparative Examples 1 and 2 t-alkyl peroxyacetates (TBPA, CPA), Comparative Example 3 t-hexylperoxyalkylate (THPH) and Comparative Example 4 t-alkylperoxyalkylate remaining styrene content It became clear that there will be less. Further, t-alkyl peroxybenzoates represented by TBPB and THPB in Comparative Examples 5 and 6, and t-alkyl peroxyal groups in which R ′ represented by TBP355 and THP355 in Comparative Examples 7 and 8 are branched alkyl groups. With the chelate, a cured product having a small amount of residual styrene could not be obtained.

  Further, even when peroxyketal (THPC), peroxymonocarbonate (TBIC) or peroxyester (TBPB) is used in combination with the t-alkyl peroxyacetate (THPA) of Examples 5 to 7, the cured product remains. It was clear that the amount of styrene decreased.

Further, the rise time (T ₉₀ -T ₁₀ ) of curing and the demoldable time (T ₉₀ ) will be considered. That is, the rise time of curing is 0.88 minutes in the case of conventional t-butyl peroxyacetate (TBPA, Comparative Example 1), and in the case of t-butyl peroxybenzoate (TBPB, Comparative Example 5). In the case of t-alkyl peroxyacetate (THPA, Example 2), which was 1.55 minutes, it was 0.45 minutes, indicating an excellent curing rate. The demoldable time is 1.40 minutes in the case of TBPA (Comparative Example 1) and 2.27 minutes in the case of TBPB (Comparative Example 5), whereas THPA (Example 2). In the case of, it was 0.84 minutes, and a sufficiently shortened result was obtained.
( Reference Example 8 , Example 9, Reference Example 10 and Reference Example 11)
In a 500 ml polyethylene container, 100 parts of the same unsaturated polyester resin as in Reference Example 1 , styrene solution of styrene / vinyl acetate block copolymer as a low shrinkage agent (Nippon Yushi Co., Ltd. Modiper SV10B-30, styrene content 70% ) 20 parts, calcium carbonate (manufactured by Nitto Flour Chemical Co., Ltd., trade name: NS # 100) as a filler, zinc stearate (manufactured by NOF Corporation, trade name: zinc stearate) as a release agent ) 4 parts and 1 part of magnesium oxide (manufactured by Kyowa Chemical Industry Co., Ltd., trade name: Kyowa Mug # 100) as a thickener. Next, the amount of t-alkyl peroxyalkylate of the present invention (TAPA, THPA, TMBPA and THPP) as a curing agent is 1 part each of the organic peroxide, and p-benzoquinone (PBQ and PBQ as a polymerization inhibitor). (Abbreviated) was added in the amounts shown in Table 2 and mixed with a stirrer to obtain a molding material. In the case where a molding material such as SMC is compression molded in a mold, it is necessary to ensure a mold flow time during which the uncured molding material can flow in the mold without gelation as described above. . Therefore, the amount of PBQ added was adjusted so that T _{0, which} is an index of the in-mold flow time, was constant when the organic peroxide was added in a pure amount of 1 part.

  The obtained molding material is wrapped with a PET film, made into a sheet and aged in a constant temperature bath at 40 ° C. for 24 hours to increase the viscosity, and then the curing characteristics of the molding material at the upper die 145 ° C. and the lower die 130 ° C. Evaluation was made with a curast meter. The results are shown in Table 2.

Furthermore, the curing characteristics after 14 days, 28 days and 56 days of the molding material after aging were similarly measured with a curast meter, and the rate of change in the curing characteristic value was determined. The results are shown in Table 3.
Further, 70 parts of the molding material before thickening and 30 parts of glass fiber (Microglass manufactured by Nippon Sheet Glass Co., Ltd., chopped strand of 6 mm in length) as a reinforcing material are mixed and wrapped with a PET film to form a sheet. Measure the residual styrene content and color before and after the boiling test of the cured product obtained by press molding at 145 ° C and upper mold 130 ° C after thickening by aging for 24 hours in a constant temperature bath at did. The results are shown in Tables 2 and 4.
(Comparative Examples 9-15)
Other than the present invention as a curing agent, t-alkyl peroxyacetate (TBPA, CPA) in which R is an alkyl group bonded with an alkyl group having 1 carbon atom or a phenyl group having 9 carbon atoms, R ′ is a primary carbon atom T-hexyl peroxyalkylate (THPH) which is an alkyl group, t-alkylperoxyalkylate (TBPL) where R is a primary alkyl group having 1 carbon atom and R ′ is 11 carbon atoms, or t-alkyl peroxyalkyl group A molding material was prepared in the same manner as in Reference Example 8 except that oxyesters (TBPB, THPB, TBP355, THP355) were used. Curing characteristics, rate of change in curing characteristics, residual styrene content of the resulting cured product, and before and after boiling test The color of was measured. The results are shown in Tables 2, 3 and 4.

表２に示した結果から、重合禁止剤としてＰＢＱを配合して型内流動時間（指標：Ｔ_０の値）をＴＢＰＢと同等の時間に確保した場合、次のことがいえる。すなわち、参考例８、実施例９、参考例１０及び参考例１１のｔ−アルキルパーオキシアルキレート（ＴＡＰＡ、ＴＨＰＡ、ＴＭＢＰＡ及びＴＨＰＰ）を硬化剤として使用すると、比較例９及び１０のｔ−アルキルパーオキシアセテート（ＴＢＰＡ、ＣＰＡ）、比較例１１のｔ−ヘキシルパーオキシアルキレート（ＴＨＰＨ）や比較例１２のｔ−アルキルパーオキシアルキレート（ＴＢＰＬ）よりも硬化物の残存スチレン量が少なくなることが分かった。さらに、硬化の立ち上がり時間（Ｔ_９０−Ｔ_１０）が短くなって成形サイクルを短縮できること、及び脱型可能時間（Ｔ_９０）が短いことが、参考例８、実施例９、参考例１０及び参考例１１と比較例９〜１２の比較から明らかである。

From the results shown in Table 2, when PBQ is blended as a polymerization inhibitor and the in-mold flow time (index: value of T ₀ ) is ensured at a time equivalent to that of TBPB, the following can be said. That is, when the t-alkyl peroxyalkylates (TAPA, THPA, TMBPA and THPP) of Reference Example 8 , Example 9, Reference Example 10 and Reference Example 11 were used as curing agents, the t-alkyl of Comparative Examples 9 and 10 were used. The amount of residual styrene in the cured product is smaller than that of peroxyacetate (TBPA, CPA), t-hexylperoxyalkylate (THPH) of Comparative Example 11 and t-alkylperoxyalkylate (TBPL) of Comparative Example 12. I understood. Furthermore, the rise time of curing (T ₉₀ -T ₁₀ ) is shortened, the molding cycle can be shortened, and the demoldable time (T ₉₀ ) is short. Reference Example 8 , Example 9, Reference Example 10 and Reference It is clear from the comparison between Example 11 and Comparative Examples 9-12.

In particular, from THPP of Reference Example 11 in which R ′ is a t-alkyl peroxypropionate having 2 carbon atoms, Reference Example 8 , Example 9 and Reference in which R ′ is a t-alkyl peroxyacetate having 1 carbon atom. TAPA, THPA, and TMBPA in Example 10 are excellent in that the amount of residual styrene in the cured product is small. Furthermore, while the TAPA of Reference Example 8 has a demoldable time (T ₉₀ ) equivalent to that of THPB shown in Comparative Example 14, the THPA of Example 9 and the TMBPA of Reference Example 10 are rapidly cured and demolded. This is superior to the TAPA of Reference Example 8 in that the productivity is improved because the possible time can be shortened.

On the other hand, in t-alkyl peroxybenzoates represented by TBPB and THPB in Comparative Examples 9 and 10, and t-alkyl peroxyalkylates in which R ′ represented by TBP355 and THP355 in Comparative Examples 11 and 12 are branched alkyl groups, residual styrene content in the cured product is large, the rise time of curing _(T 90 _{-T 10)} is long, further demolding available time _{(T 90)} was also longer result.

Further, from the results shown in Table 3, the molding materials using the t-alkyl peroxyalkylates (TAPA, THPA, TMBPA and THPP) of Reference Example 8 , Example 9, Reference Example 10 and Reference Example 11 as curing agents. Since the change rate of the curing characteristic values represented by ΔT ₀ and ΔT ₉₀ is small, it is clear that the curing characteristic of the molding material changes little over time and the storage stability of the molding material is high. On the other hand, in the molding material using TBPA of Comparative Example 9, THPB of Comparative Example 14 or TBP355 of Comparative Example 15 as a curing agent, ΔT ₀ is particularly large, so that the curing of the molding material is performed over time. The speed of the molding material could not be secured, and the curing reaction proceeded while the molding material flowed in the mold, and the quality such as the smoothness of the surface of the resulting molded product was lowered. In addition, since the molding material using the CPA of Comparative Example 10 did not cure after being left for 2 weeks at 25 ° C., the stability of the molding material was low.

Further, from the results shown in Table 4, curing obtained using the t-alkyl peroxyalkylates (TAPA, THPA, TMBPA and THPP) of Reference Example 8 , Example 9, Reference Example 10 and Reference Example 11 Since the b value after the boiling test for 500 hours does not increase, the cured product has little yellowing. On the other hand, TBPA of Comparative Example 9 and TBPB of Comparative Example 13 are not preferable because the b value after the boiling test is high, resulting in a yellowing of the cured product.

In addition, the TMBPA of Reference Example 10 is rapidly cured, and the amount of PBQ added as a polymerization inhibitor in order to ensure in-mold flow time (T ₀ ) is increased, which causes the b value of the cured product after curing. Is expensive. On the other hand, in the THPA of Example 9, the addition amount of PBQ blended as a polymerization inhibitor in order to ensure in-mold flow time is small, and the coloring derived from the polymerization inhibitor of the cured product after curing is small. It is superior to TMBPA of Reference Example 10.
( Reference Example 12 , Example 13 and Reference Example 14)
Unsaturated polyester resin containing styrene (manufactured by Japan Composite Co., Ltd., trade name: polyhop 6370, styrene content 43.1%) 87 parts, methyl methacrylate (MMA) 10 parts as alkyl (meth) acrylate, (poly) Composed of 3 parts of neopentyl glycol dimethacrylate (NPG) as alkylene glycol di (meth) acrylate, styrene and alkyl (meth) acrylate other than styrene as unsaturated monomer (styrene / MMA / NPG = 37.5 / 10 / 3 parts), except that 100 parts of unsaturated polyester resin was used, a molding material was prepared in the same manner as in Reference Example 1, and the curing characteristics at the upper mold 145 ° C. and the lower mold 130 ° C. using the curast meter, and the mold clamping Measure the amount of residual unsaturated monomer in the cured product taken out 2.5 minutes after . The results are shown in Table 5.

（参考例１５、実施例１６及び参考例１７）
スチレンを含有する不飽和ポリエステル樹脂（ジャパンコンポジット（株）製、商品名：ポリホープ６３７０、スチレン含有量４３．１％）９０部、水酸基末端（ポリ）アルキレングリコールモノ（メタ）アクリレートとして２−ヒドロキシエチルメタクリレート（ＨＥＭＡ）１０部からなる、不飽和単量体としてスチレンとスチレン以外のアルキル（メタ）アクリレート（スチレン／ＨＥＭＡ＝３８．８／１０部）を含む不飽和ポリエステル樹脂１００部を用いた以外は参考例１と同様に成形材料を調製した。得られた成形材料について、キュラストメーターを用いて上型１４５℃、下型１３０℃における硬化特性と、型締めから２．５分後に取り出した硬化物の残存不飽和単量体量を測定した。それらの結果を表６に示す。

( Reference Example 15 , Example 16 and Reference Example 17)
Unsaturated polyester resin containing styrene (manufactured by Japan Composite Co., Ltd., trade name: Polyhop 6370, styrene content 43.1%) 90 parts, 2-hydroxyethyl as hydroxyl-terminated (poly) alkylene glycol mono (meth) acrylate Except for using 100 parts of unsaturated polyester resin comprising 10 parts of methacrylate (HEMA) and containing styrene and an alkyl (meth) acrylate other than styrene (styrene / HEMA = 38.8 / 10 parts) as an unsaturated monomer. A molding material was prepared in the same manner as in Reference Example 1 . With respect to the obtained molding material, the curing characteristics at an upper mold of 145 ° C. and a lower mold of 130 ° C. were measured using a curast meter, and the residual unsaturated monomer amount of the cured product taken out 2.5 minutes after clamping. . The results are shown in Table 6.

表５及び６に示した結果から、参考例１２、実施例１３、参考例１４、参考例１５、実施例１６及び参考例１７のｔ−アルキルパーオキシアルキレート（ＴＡＰＡ、ＴＨＰＡ及びＴＭＢＰＡ）を硬化剤として使用すると、不飽和単量体としてスチレンと、スチレン以外のアルキル（メタ）アクリレートであるメチルメタクリレート、（ポリ）アルキレングリコールジ（メタ）アクリレートであるネオペンチルグリコールジメタクリレート、又は水酸基末端（ポリ）アルキレングリコールモノ（メタ）アクリレートである２−ヒドロキシエチル（メタ）アクリレートを含む不飽和ポリエステル樹脂を硬化させることができ、残存不飽和単量体の少ない硬化物を得ることができた。
（参考例１８、実施例１９及び参考例２０）
ビニルエステル樹脂（昭和高分子（株）製、商品名：リポキシＲ−８０２、スチレン含有量５０．０％）１００部を用いた以外は参考例１と同様に成形材料を調製し、キュラストメーターを用いて上型１３０℃、下型１２０℃における硬化特性と、型締めから１０分後に取り出した硬化物の残存不飽和単量体量を測定した。それらの結果を表７に示す。

From the results shown in Tables 5 and 6, the t-alkyl peroxyalkylates (TAPA, THPA and TMBPA) of Reference Example 12 , Example 13, Reference Example 14, Reference Example 15, Example 16 and Reference Example 17 were cured. When used as an agent, styrene as an unsaturated monomer, methyl methacrylate which is an alkyl (meth) acrylate other than styrene, neopentyl glycol dimethacrylate which is a (poly) alkylene glycol di (meth) acrylate, or a hydroxyl terminal (poly ) Unsaturated polyester resin containing 2-hydroxyethyl (meth) acrylate which is alkylene glycol mono (meth) acrylate can be cured, and a cured product having a small amount of residual unsaturated monomer can be obtained.
( Reference Example 18 , Example 19 and Reference Example 20)
A molding material was prepared in the same manner as in Reference Example 1 except that 100 parts of vinyl ester resin (manufactured by Showa Polymer Co., Ltd., trade name: Lipoxy R-802, styrene content 50.0%) was used. Were used to measure the curing characteristics of the upper mold at 130 ° C. and the lower mold at 120 ° C., and the amount of residual unsaturated monomer in the cured product taken out 10 minutes after clamping. The results are shown in Table 7.

表７に示した結果から、参考例１８、実施例１９及び参考例２０のｔ−アルキルパーオキシアルキレート（ＴＡＰＡ、ＴＨＰＡ及びＴＭＢＰＡ）を硬化剤として使用すると、ビニルエステル樹脂を硬化させることができ、残存不飽和単量体の少ない硬化物を得ることができた。
（参考例２１、実施例２２及び参考例２３）
５００ｍｌのポリエチレン容器に、アクリルシラップ（ポリメタクリル酸メチル（三菱レーヨン（株）製、商品名：ＢＲ−５２）２０部及びメチルメタクリレート８０部を含む）３９．５部、架橋剤としてネオペンチルグリコールジメタクリレート０．５部、充填剤としてシリカ（トクヤマ（株）製、商品名：ＳＥ−１５）５９部、シランカップリング剤としてγ−メタクリルオキシプロピルトリメトキシシラン１部を入れ、（メタ）アクリル系樹脂の原料組成物１００部を調製した。次いで、硬化剤として本発明のｔ−アルキルパーオキシアセテート（ＴＡＰＡ、ＴＨＰＡ、ＴＭＢＰＡ）をそれぞれ有機過酸化物純分で０．４部となる量を添加し、攪拌機で混合することによりコンパウンドを得た。そのコンパウンドをキュラストメーターを用いて上型１２０℃、下型１２０℃で硬化させ、型締めから１０分後に取り出した硬化物の残存スチレン量を測定した。その結果を表８に示す。

From the results shown in Table 7, when the t-alkyl peroxyalkylates (TAPA, THPA and TMBPA) of Reference Example 18 , Example 19 and Reference Example 20 are used as curing agents, the vinyl ester resin can be cured. Thus, a cured product with little residual unsaturated monomer could be obtained.
( Reference Example 21 , Example 22 and Reference Example 23)
In a 500 ml polyethylene container, 39.5 parts of acrylic syrup (polymethyl methacrylate (Mitsubishi Rayon Co., Ltd., trade name: BR-52) 20 parts and methyl methacrylate 80 parts included), neopentyl glycol di as a crosslinking agent 0.5 parts of methacrylate, 59 parts of silica (trade name: SE-15, manufactured by Tokuyama Corporation) as filler, 1 part of γ-methacryloxypropyltrimethoxysilane as silane coupling agent, (meth) acrylic 100 parts of a resin raw material composition was prepared. Next, t-alkyl peroxyacetate (TAPA, THPA, TMBPA) of the present invention is added as a curing agent in an amount of 0.4 parts each of pure organic peroxide, and a compound is obtained by mixing with a stirrer. It was. The compound was cured using a curast meter at an upper mold of 120 ° C. and a lower mold of 120 ° C., and the residual styrene content of the cured product taken out 10 minutes after the mold clamping was measured. The results are shown in Table 8.

表８に示した結果から、参考例２１、実施例２２及び参考例２３のｔ−アルキルパーオキシアルキレート（ＴＡＰＡ、ＴＨＰＡ及びＴＭＢＰＡ）を硬化剤として使用すると、（メタ）アクリル樹脂を硬化させることができ、残存不飽和単量体の少ない硬化物を得ることができた。

From the results shown in Table 8, when the t-alkyl peroxyalkylates (TAPA, THPA and TMBPA) of Reference Example 21 , Example 22 and Reference Example 23 are used as curing agents, the (meth) acrylic resin is cured. And a cured product with little residual unsaturated monomer could be obtained.

It should be noted that the present embodiment can be implemented with the following modifications.
A plurality of t-alkyl peroxyalkylates represented by the general formula (1) can be used in combination as a curing agent.

-In addition to the hardening | curing agent containing t-alkyl peroxyalkylate represented by General formula (1), it is also possible to use the hardening accelerator which accelerates | stimulates the hardening.
-A monomer having a high boiling point can be used as the unsaturated monomer in order to reduce the dissipation amount of the unsaturated monomer such as styrene. It is also possible to add waxes in order to prevent curing inhibition due to oxygen in the air.

As the curing agent, an organic peroxide having a low 10-hour half-life temperature, for example, a peroxy ester such as t-butyl peroxy 2-ethylhexanoate can be blended.
Furthermore, the technical idea grasped from the embodiment will be described below.

  The curing agent for radical polymerization type thermosetting resin according to claim 1, wherein the t-alkyl peroxyalkylate represented by the general formula (1) is t-hexyl peroxyacetate. When comprised in this way, while radical-curing thermosetting resin hardens | cures quickly, while being able to shorten mold release time, the unsaturated monomer in hardened | cured material can be reduced.

  The content of the t-alkyl peroxyalkylate represented by the general formula (1) is 50% by mass or more, and the curing agent for radical polymerization type thermosetting resin according to claim 1. When comprised in this way, the function of t-alkyl peroxyalkylate can fully be exhibited.

  The molding material according to claim 2, further comprising a filler. When configured in this way, it can exert effects such as suppression of appearance defects such as nests and voids during pressure molding by increasing the viscosity of the molding material, improvement of rigidity of the cured product, reduction of shrinkage, etc. it can.

  The molding material according to claim 2, further comprising an organic peroxide other than the t-alkyl peroxyalkylate represented by the general formula (1). When comprised in this way, the hardening characteristic and hardening degree of a molding material can be improved.

  A cured product obtained by curing with the molding material curing method according to claim 5. In this case, the residue of the unsaturated monomer in the cured product can be reduced.

Claims (5)

A curing agent for a radical polymerization type thermosetting resin, comprising a t-alkyl peroxyalkylate represented by the following general formula (1).

(Wherein, R represents an an alkyl group, R 'is an alkyl group of 1 to 4 carbon atoms, straight-chain having 3 carbon atoms) The molding material characterized by mix | blending 0.1-5 mass parts of t-alkyl peroxyalkylates of Claim 1 with 100 mass parts of radical polymerization type thermosetting resins. The molding material according to claim 2, further comprising a low shrinkage agent, a filler, a thickener, a release agent, a polymerization inhibitor and a reinforcing material. The molding material according to claim 2 or 3, wherein the radical polymerization type thermosetting resin is an unsaturated polyester resin. A method for curing a molding material, comprising curing the molding material according to any one of claims 2 to 4 at 100 to 180 ° C.