JP6880493B2 - Hardener composition, resin composition and cured resin - Google Patents

Description

The present invention relates to a curing agent composition, a resin composition, and a cured resin product.

The vinyl ester resin composition is widely used in applications such as paints, decorative boards, putties, resin concretes, construction members, transportation equipment, and industrial equipment. Specifically, the vinyl ester resin composition is prepared, for example, by dissolving (diluting) a vinyl ester resin as a raw material in a radically polymerizable monomer such as a styrene monomer, and adding a curing agent (organic peroxide) or promoting curing to the mixture. Prepared by adding the agent. Then, when the resin composition is cured, it is used as a cured product (molded body) in the above-mentioned applications such as decorative boards and construction members.

More specific examples of the above resin composition include, for example, a vinyl ester resin composition containing methyl ethyl ketone peroxide (hereinafter, also referred to as MEKPO) as a curing agent and a cobalt-based accelerator as a curing accelerator, or benzoyl as a curing agent. Peroxide (hereinafter, also referred to as BPO), vinyl ester resin composition containing dimethylaniline as a curing accelerator, and the like.

However, as described above, when MEKPO, a cobalt-based accelerator and a vinyl ester resin are mixed, there is a problem that foaming occurs and the work cannot be continued. Further, when BPO, dimethylaniline and vinyl ester resin are mixed, the above-mentioned foaming does not occur, but the vinyl ester resin composition is difficult to cure completely, and a styrene monomer or the like is contained in the cured vinyl ester resin (molded product). There was a problem that the radically polymerizable monomer of the above remained.

In order to solve the above problems, in Patent Document 1, as a curing agent, purified MEKPO from which hydrogen peroxide causing foaming, which is contained in MEKPO in advance, and a tertiary alkyl peroxy ester (t-butyloxy ester) are removed. By using a vinyl ester resin composition containing benzoate, etc.), a metal soap (cobalt naphthenate, etc.) as a curing accelerator, and an acetoacetate ester, the above-mentioned foaming does not occur, and the residual amount of styrene monomer is very large. It has been clarified that a cured vinyl ester resin (molded product) having a small amount of hardness and high curability can be obtained.

Special Publication No. 57-24085

On the other hand, the vinyl ester resin composition is being developed into a carbon fiber reinforced resin (hereinafter, also referred to as CFRP). CFRP is a material that is lightweight, has high strength, does not rust, and has many excellent properties such as heat resistance, and is used in aircraft, racing cars, and high-end sports equipment.

Further, in recent years, application to automobile applications requiring weight reduction has been promoted, and the structure molded for this application is becoming more complicated and thinner than conventional applications. In addition, with the application to the application, reduction of volatile organic compounds (hereinafter, also referred to as VOC) is inevitably required. The VOC here refers to a radically polymerizable monomer such as a styrene monomer for dissolving (diluting) a vinyl ester resin as a raw material. Therefore, even in a thin molded body, it is required to reduce the residual amount of VOC of a radically polymerizable monomer such as a styrene monomer in the molded body.

However, in a thin molded body as described above, heat is easily dissipated and heat is not easily stored when the resin composition is cured. Therefore, the VOC of the radically polymerizable monomer tends to remain in the molded body. With the conventional resin composition as in Document 1, the residual amount of VOC of the radically polymerizable monomer could not be reduced.

The present invention has been made in view of the above circumstances, and has a resin composition in which foaming does not occur when a curing agent, a curing accelerator, a vinyl ester resin, and a radically polymerizable monomer are mixed, and the curing rate is good. A product can be obtained, and the residual amount of VOC of the radically polymerizable monomer in the cured resin product (molded product) obtained from the resin composition can be reduced even when the thickness of the cured product is thin. It provides a curing agent composition.

The present invention also provides a resin composition containing the above-mentioned curing agent composition and a cured resin product obtained from the resin composition.

The present invention is a curing agent composition containing a curing agent and a curing accelerating aid, wherein the curing agent is (a) a mixture of methyl ethyl ketone peroxide and (b) t-hexyl peroxyacetate, and the curing accelerating. The auxiliary agent is (c) acetoacetic ester, and the content of hydrogen peroxide in the mixture is 0.5% by weight or less, and in a total of 100 parts by weight of the above (a) and the above (b), The vinyl ester (a) is 40 to 90 parts by weight, and the vinyl ester (c) is 5 to 50 parts by weight with respect to 100 parts by weight of the total of (a) and (b). Concerning a curing agent composition for resins.

The present invention relates to the curing agent composition, a vinyl ester resin, a radically polymerizable monomer, and a resin composition containing a metal-based curing accelerator.

The present invention relates to a cured resin product obtained from the resin composition.

The curing agent composition of the present invention is a specific amount of (a) methyl ethyl ketone peroxide mixture and (b) t-hexyl peroxyacetate, and the (a) is a redox (reduction) reaction with a metal-based curing accelerator. Moreover, hydrogen peroxide, which causes foaming, is 0.5% by weight or less, and (b) shows a good curing rate because decomposition starts at a low temperature and radicals are generated. Therefore, even when the curing accelerator, the vinyl ester resin, and the radically polymerizable monomer are added to the curing agent composition in which the above (a) and (b) are used in combination, the resin composition does not foam and does not foam. , Has a good curing rate. Further, in the resin composition of the present invention, since the radical generated from the compound according to (b) above has high efficiency of the polymerization reaction, even when the obtained cured resin composition (molded body) is thin, the present invention is applicable. The residual amount of VOC of the radically polymerizable monomer such as the styrene monomer in the cured product can be reduced. Therefore, the resin composition of the present invention can be applied to applications such as carbon fiber reinforced resins that are complicated and require thinning.

The curing agent composition of the present invention contains a curing agent and a curing accelerating aid.

<Hardener>
The curing agent of the present invention is at least an organic peroxide containing (a) a mixture of methyl ethyl ketone peroxide and (b) t-hexyl peroxyacetate.

（式（１）中、ｎは１〜６の整数を表す。）で表される鎖状のメチルエチルケトンパーキサイド化合物、および一般式（２）：

で表される化合物などの環状のメチルエチルケトンパーキサイド化合物を含み、かつ未反応の過酸化水素、未反応のメチルエチルケトンを含んでいてもよい混合物である。 The methyl ethyl ketone peroxide mixture (a) can be produced by a step of reacting hydrogen peroxide with methyl ethyl ketone (for example, JP-A-10-87652, JP-A-2007-197515, etc.), and the general formula (1):

(In the formula (1), n represents an integer of 1 to 6), and the chain methyl ethyl ketone parkside compound represented by the general formula (2):

It is a mixture containing a cyclic methyl ethyl ketone parkside compound such as the compound represented by, and which may contain unreacted hydrogen peroxide and unreacted methyl ethyl ketone.

The unreacted hydrogen peroxide is 0.5% by weight or less in the (a) methyl ethyl ketone peroxide mixture. The unreacted hydrogen peroxide is preferably 0.5% by weight or less, preferably 0.3% by weight, in the mixture of (a) methyl ethyl ketone peroxide from the viewpoint of suppressing foaming in the resin composition of the present invention. More preferably: From the viewpoint of productivity, the (a) methyl ethyl ketone peroxide mixture may contain 0.05% by weight or more of the unreacted hydrogen peroxide in the (a) methyl ethyl ketone peroxide mixture.

The (a) methyl ethyl ketone peroxide mixture is subjected to a purification step after the step of reacting the hydrogen peroxide with methyl ethyl ketone in order to reduce the content of unreacted hydrogen peroxide in the (a) methyl ethyl ketone peroxide mixture. It is preferable to provide. The purification step is hydrogen peroxide obtained by adding unreacted hydrogen peroxide to ammonium sulfate or sodium carbonate with a crude methyl ethyl ketone peroxide mixture obtained after the step of reacting hydrogen peroxide with methyl ethyl ketone. This is a step of removing the substance.

The methyl ethyl ketone peroxide mixture (a) is preferably treated with 5 to 15 parts by weight, more preferably 7 to 13 parts by weight, based on 100 parts by weight of the crude methyl ethyl ketone peroxide mixture. The treatment temperature is preferably 10 to 30 ° C. The treatment time is preferably 10 to 60 minutes, more preferably 15 to 25 minutes.

で表される化合物である。 The t-hexyl peroxy acetate is described in the general formula (3):

It is a compound represented by.

The content of the (a) methyl ethyl ketone peroxide mixture is 40 to 90 parts by weight and 50 to 80 parts by weight based on 100 parts by weight of the total of the (a) methyl ethyl ketone peroxide mixture and (b) t-hexyl peroxyacetate. More preferably, it is a part.

The curing agent comprises the (a) methyl ethyl ketone peroxide mixture and the (b) t-hexyl peroxyacetate, but may also contain known organic peroxides. For example, the total ratio of the above (a) and the above (b) in the curing agent is preferably about 80% by weight or more, more preferably 90% by weight or more, and more preferably 95% by weight or more. Is even more preferable.

<Curing accelerating aid>
The curing accelerator of the present invention is (c) acetoacetic ester. Examples of the (c) acetoacetic ester include methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate and the like, with methyl acetoacetate and ethyl acetoacetate being preferred. (C) The acetoacetic ester may be used alone or in combination of two or more.

The content of the acetoacetic ester (c) is 5 to 50 parts by weight, and 8 to 45 parts by weight, based on 100 parts by weight of the total of (a) and (b). It is preferably 10 parts by weight to 40 parts by weight, more preferably 10 parts by weight.

The resin composition of the present invention contains the curing agent composition, a vinyl ester resin, a radically polymerizable monomer, and a metal-based curing accelerator.

<Vinyl ester resin>
The vinyl ester resin of the present invention is an epoxy (meth) acrylate obtained by converting an epoxy resin and α, β-unsaturated monocarboxylic acid into a vinyl ester resin by a known method.

Examples of the epoxy resin include bisphenol A, bisphenol AD, bisphenol F and bisphenol S diglycidyl ethers and their high molecular weight homologues, phenol novolac type polyglycidyl ethers, cresol novolac type polyglycidyl ethers and the like. Can be mentioned. Furthermore, these halogenated derivatives can also be used. The epoxy resin may be used alone or in combination of two or more.

Examples of the α, β-unsaturated monocarboxylic acid include unsaturated monocarboxylic acids derived from acrylic acid, methacrylic acid, crotonic acid, tiglic acid, cinnamic acid, acrylic acid and / or methacrylic acid. Be done. The α and β-unsaturated monocarboxylic acids may be used alone or in combination of two or more.

The reaction in the vinyl esterification is to react the epoxy group of the epoxy resin with the carboxylic acid group of α, β-unsaturated monocarboxylic acid. The conditions of the reaction are not limited in any way, but for example, the reaction is carried out at a reaction temperature of 80 ° C. to 140 ° C., if necessary, using a reaction catalyst. Examples of the catalyst include tertiary amines such as benzyldimethylamine, triethylamine, N, N-dimethylaniline, triethylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol, and trimethylbenzylammonium chloride. Examples thereof include quaternary ammonium salts and metal salts such as lithium chloride. The catalyst may be used alone or in combination of two or more.

<Radical polymerizable monomer>
The radically polymerizable monomer of the present invention preferably contains a styrene monomer as a monomer component. Further, in addition to the styrene monomer, another radically polymerizable monomer may be contained.

Examples of the other radically polymerizable monomer include styrene-based monomers such as vinyltoluene, chlorostyrene, dichlorostyrene, t-butylstyrene, divinylbenzene, and vinylnaphthalene; vinyl monomers such as ethylvinyl ether and methylvinyl ketone; diallyl. Allyl compounds such as succinate and triallyl cyanurate; and their oligomers and the like. The other radically polymerizable monomers may be used alone or in combination of two or more.

Examples of the metal-based curing accelerator of the present invention include cobalt-based curing accelerators such as cobalt naphthenate and cobalt octylate; iron-based curing accelerators such as iron naphthenate and iron octylate; manganese naphthenate and manganese octylate. Manganese-based curing accelerators such as. Among these, it is preferable to use a cobalt-based curing accelerator. The metal-based curing accelerator may be used alone or in combination of two or more.

The content of the curing agent composition is preferably 0.2 to 8 parts by weight, and 5 parts by weight or less, based on 100 parts by weight of the total of the vinyl ester resin and the radically polymerizable monomer. More preferably, it is more preferably 4 parts by weight or less, and the resin composition exhibits better curing characteristics in the above range of contents.

The proportion of the vinyl ester resin is preferably 30 to 70% by weight based on the total of the vinyl ester resin and the radically polymerizable monomer.

The content of the metal-based curing accelerator is preferably 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the total of the vinyl ester resin and the radically polymerizable monomer.

In addition, the resin composition of the present invention may contain additives such as a polymerization inhibitor, a filler, a low shrinkage agent, a thickener, a mold release agent, and a strengthening agent.

Examples of the polymerization inhibitor include hydroquinone, parabenzoquinone, and dibutylhydroxytoluene. The polymerization inhibitor may be used alone or in combination of two or more. The polymerization inhibitor is used in the resin composition at a ratio of about 10 to 1000 ppm.

Examples of the filler include calcium carbonate, aluminum hydroxide, hollow silica balloon, glass balloon, silica gel, Aerosil, clay and the like. The filler may be used alone or in combination of two or more. The filler is used in an amount of about 1 to 1000 parts by weight with respect to a total of 100 parts by weight of the vinyl ester resin and the radically polymerizable monomer.

Examples of the low shrinkage agent include polystyrene, polyvinyl acetate, polymethyl methacrylate, crosslinked polystyrene, and styrene / vinyl acetate block copolymers. The low shrinkage agent may be used alone or in combination of two or more. The low shrinkage agent is used in an amount of about 1 to 100 parts by weight with respect to a total of 100 parts by weight of the vinyl ester resin and the radically polymerizable monomer.

Examples of the release agent include wax, polyvinyl alcohol solution, silicone-based release agent, zinc stearate, calcium stearate and the like. The release agent may be used alone or in combination of two or more. The release agent is used in an amount of about 0.01 to 2 parts by weight with respect to a total of 100 parts by weight of the vinyl ester resin and the radically polymerizable monomer.

Examples of the reinforcing agent include glass fibers such as chopped strands, chopped strand mats, and roving cloth; carbon fibers, aramid fibers, and the like. The fortifier may be used alone or in combination of two or more. The reinforcing agent is used in an amount of about 0.1 to 100 parts by weight with respect to a total of 100 parts by weight of the vinyl ester resin and the radically polymerizable monomer.

The cured resin product of the present invention is obtained by curing (molding) the resin composition.

The method for curing (molding) the cured resin product is not limited, but for example, a hand lay-up molding method, a spray-up molding method, a filament winding molding method, a resin injection molding method, a sheet molding compound ( SMC) press method, resin transfer molding (RTM) method, pultrusion molding method, vacuum molding method, pneumatic molding method, compression molding method, injection molding method, casting method, spray method and the like. In particular, when the resin composition contains the reinforcing agent, it is preferable to adopt a hand lay-up molding method, a spray-up molding method, a sheet molding compound (SMC) press method, and a resin transfer molding (RTM) method. The curing (molding) temperature is about 0 to 80 ° C.

The thickness of the cured resin product is usually about 5 to 30 mm. The thickness of the cured resin product is usually about 2 to 30 mm in automobile applications where thinning of the cured resin product is required, and more preferably about 2 to 20 mm for members requiring further thinness. Is about 2 to 10 mm, and more preferably about 2 to 4 mm.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Manufacturing example 1>
As a crude methyl ethyl ketone peroxide mixture, 100 parts by weight of Permec S (manufactured by NOF CORPORATION) was treated with 10 parts by weight of a 35% ammonium sulfate aqueous solution at 15 ° C. for 20 minutes, and the hydrogen peroxide content was 0. A 3 wt% (a) methyl ethyl ketone peroxide mixture was obtained. The content of hydrogen peroxide was determined by an external standard method for LC analysis under the following conditions.
Column: Phenomenex OnexMonolytic C18 4.6 mm I. D. × 100 mm
Temperature: 45 ° C
Mobile phase: water = 100 0.5 ml / min
Detector: UV detector (detection wavelength = 220 nm)

<Manufacturing example 2>
As a crude methyl ethyl ketone peroxide mixture, 100 parts by weight of Permec S (manufactured by NOF CORPORATION) was treated with 5 parts by weight of a 35% ammonium sulfate aqueous solution at 15 ° C. for 20 minutes, and the hydrogen peroxide content was 0. A 5% by weight (a) methyl ethyl ketone peroxide mixture was obtained.

<Manufacturing example 3>
Permec S (manufactured by NOF CORPORATION) having a hydrogen peroxide content of 1.2% by weight was used.

Example 1
<Manufacturing of curing agent composition>
In a polyethylene container, as a curing agent, 70 parts by weight of (a) methyl ethyl ketone peroxide mixture (hereinafter, also referred to as MEKPO mixture) obtained in Production Example 1 above, and (b) t-hexyl peroxyacetate (trade name:). Perhexyl A, manufactured by NOF CORPORATION) (hereinafter, also referred to as THPA) 30 parts by weight and (c) methyl acetate acetate 20 parts by weight as a curing accelerator aid are added and mixed to produce the curing agent composition of Example 1. did. In addition to the organic peroxide, the above-mentioned (b) contains a diluent and the like, and the blending amount of the above-mentioned (b) corresponds to the blending amount of the organic peroxide.

Examples 2-5, Comparative Examples 1-5
In Example 1, the same operation as in Example 1 was performed to cure the curing agent, except that the curing agent used for preparing the curing agent composition, the curing accelerator aid, and the blending amounts thereof were changed as shown in Table 1. The agent composition was produced.

Example 1-1
<Manufacturing of resin composition>
A resin mixture containing a vinyl ester resin and a styrene monomer as a radically polymerizable monomer in a polyethylene container (trade name: Lipoxy R-802, manufactured by Showa Denko Co., Ltd., vinyl ester resin concentration: 50% by weight, styrene monomer concentration: 50% by weight. %) 0.5 part by weight of cobalt naphthenate (6% by weight mineral spirit diluted solution) as a metal-based curing accelerator was added to 100 parts by weight and mixed. Next, 1.5 parts by weight of the curing agent composition of Example 1 was added to the obtained mixed composition and mixed to produce a resin composition of Example 1-1.

Examples 1-2-1-3, 2-1-5-1, Comparative Examples 1-1-5-1
In Example 1-1, the same operation as in Example 1-1 was carried out except that the type of the curing agent composition and the blending amount thereof were changed as shown in Table 2 or Table 3, and the resin composition was produced. did.

The curing agent composition and the resin composition obtained in the above Examples and Comparative Examples were evaluated as follows.

<Evaluation of foaming of resin composition>
In the evaluation of foaming of the resin composition, the presence or absence of foaming of the resin composition immediately after production was visually observed in the production of the resin compositions of the above Examples and Comparative Examples.

<Evaluation of curing characteristics of curing agent composition>
The curing characteristics of the curing agent composition were measured at 25 ° C. using the curing agent compositions of Examples and Comparative Examples obtained above according to the test method of room temperature curing characteristics (heat generation method) of JIS K6901: 2008. A curing test was carried out, and the characteristic values were obtained as follows.
Gelling time (GT): Time (minutes) required from the start of the test to the test temperature plus 5 ° C.
Curing time (CT): Time required for PET from the start of the test (minutes)
Maximum heat generation temperature (PET) (° C)

<Evaluation of residual amount of styrene monomer in cured resin>
The residual amount of the styrene monomer of the cured resin product was evaluated by sandwiching a mold made of a silicone rubber spacer with a gap so that air could escape upward and sandwiching it between two glass plates to which a PET film was attached. The resin compositions of the above Examples and Comparative Examples were poured so that the size of the cured resin product was 50 mm in length × 100 mm in width and the thickness was 5 mm or 3 mm, and the following predetermined conditions ( In (a) or (b)), a cast plate-shaped resin cured product was obtained by leaving it to stand.
(A): Temperature 25 ° C., left for 1 week (b): After being left in the above (a), further left at a temperature of 80 ° C. for 2 hours.

The cured resin obtained above is crushed for 10 seconds with a crusher (trade name: Willey type crusher manufactured by Yoshida Seisakusho), and 3 g of the obtained crushed product and 20 mL of styrene are placed in a 50 mL Erlenmeyer flask and sealed. The styrene monomer was extracted from the cured resin product after being left at room temperature for 24 hours. Further, 0.03 g of the internal standard substance n-decane is added and then filtered, and the filtrate is analyzed by gas chromatography to determine the area ratio of styrene monomer to n-decane, and the residual amount of styrene monomer is quantified by the internal standard method. did.

<Evaluation of appearance of cured resin>
In the evaluation of the appearance of the cured resin product, the presence or absence of cracks was visually evaluated for the appearance of the cured resin product having a thickness of 3 mm obtained under the above condition (a).

<Evaluation of curability of cured resin>
The degree of curing of the resin curing was evaluated by measuring the hardness of the cured resin product having a thickness of 3 mm obtained under the above condition (b). The hardness was measured with a Barcor hardness meter GYZJ934-1 manufactured by Barber Coleman.

In Table 1, THPA is t-hexyl peroxyacetate (trade name: Perhexyl A, manufactured by NOF CORPORATION);
TBTB is t-butyl peroxybenzoate (trade name: Perbutyl Z, manufactured by NOF CORPORATION).
TAPA stands for t-amyl peroxyacetate (trade name: Per Amil A, manufactured by NOF CORPORATION).

From the results of the above Examples and Comparative Examples, the resin composition of the present invention does not foam, has a good curing rate, and is radically polymerizable in the cured resin product obtained from the resin composition. Since the residual amount of VOC of the monomer can be reduced even when the thickness of the cured product is thin, it is useful as a resin composition used for carbon fiber reinforced resin.

Claims (5)

A curing agent composition containing a curing agent and a curing accelerating aid.
The curing agent is (a) a mixture of methyl ethyl ketone peroxide and (b) t-hexyl peroxyacetate.
The curing accelerator is (c) acetoacetic ester,
The content of hydrogen peroxide in the mixture is 0.5% by weight or less.
In the total of 100 parts by weight of the above (a) and the above (b), the above (a) is 40 to 90 parts by weight.
A curing agent composition for a vinyl ester resin, wherein (c) is 5 to 50 parts by weight with respect to 100 parts by weight of the total of (a) and (b). A resin composition comprising the curing agent composition according to claim 1, a vinyl ester resin, a radically polymerizable monomer, and a metal-based curing accelerator. The resin composition according to claim 2, wherein the curing agent composition is 0.2 to 8 parts by weight based on 100 parts by weight of the total of the vinyl ester resin and the radically polymerizable monomer. A cured resin product obtained from the resin composition according to claim 2 or 3. The resin composition according to claim 2 or 3, wherein the resin composition is used for a carbon fiber reinforced resin.