JP2008239748A - Thermosetting resin composition and thermosetting resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting resin composition giving molded products decreased in styrene-based monomer and formaldehyde which are diffused in the air, and to provide thermosetting resin molded products molded from the thermosetting resin composition. <P>SOLUTION: The thermosetting resin composition comprises an unsaturated polyester resin and/or a vinyl ester resin, a styrene-based monomer, a peroxy ketal and/or a peroxy ester, and a hydrazide compound, wherein the 10 hour half-time temperature of the peroxy ketal and/or the peroxy ester is 66-97°C and the hydrazide compound of 0.05-2 mass% is contained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermosetting resin composition and a molded product obtained from the thermosetting resin composition.

  Thermosetting resin compositions containing curing agents, reinforcing fibers, low shrinkage agents, etc. in thermosetting resins such as unsaturated polyester resins are industrially molded into residential equipment, automobile parts, electrical parts, etc. Widely used. In particular, the bulk molding compound (BMC) is usually a curing agent, a reinforcing fiber, a low shrinkage agent, a filler, a thickener, a release agent, a polymerization inhibitor, a colorant, a diluent, etc. Is a molding material obtained by blending, mixing, and forming into a bulk shape. It has excellent moldability by molding methods such as compression molding, transfer molding, injection molding, etc., and has excellent dimensional accuracy and mechanical strength. Therefore, it is widely used for automobile parts, electrical parts and the like that require strict dimensional accuracy.

  In general, a radical reactive monomer such as a styrene monomer is added to the thermosetting resin composition as a crosslinking agent. This styrenic monomer should originally constitute a part of a molded cured product obtained by a curing reaction with an unsaturated polyester resin or vinyl ester resin. However, in practice, a small amount of unreacted styrene monomer may remain in the molded product, and the styrene monomer may be diffused into the atmosphere. Moreover, it is known that a styrene-type monomer reacts with oxygen in the air to form formaldehyde, and this formaldehyde may be diffused into the atmosphere.

  On the other hand, in recent years, so-called sick house syndrome, in which a resident is unwell due to VOC (Volatile Organic Compounds) emitted from building materials and interior materials of houses, has become a problem. There is a strong demand to reduce emissions. In response to this, the Ministry of Health, Labor and Welfare published a VOC indoor concentration guideline value in 2000. In addition, the Japan Automobile Manufacturers Association considers the vehicle interior space as a part of the living space, while the concentration test method taking into account the environment different from the way the car is used and the living space, so-called “vehicle interior VOC test method”. Was formulated. Targeting new passenger cars from 2007 onwards, it is required to meet the standards of the 13 substances VOC indoor concentration guideline established by the Ministry of Health, Labor and Welfare, the so-called “voluntary efforts to reduce vehicle interior VOC”.

  For this reason, there is a strong demand to reduce the residual styrene monomer in the molded product and formaldehyde generated from the styrene monomer to reduce the concentration of the styrene monomer and formaldehyde in the air.

Examples of the thermosetting resin composition include a thermosetting resin containing a styrene monomer and a monomer other than a styrene monomer such as (meth) acrylate, and a polymerization with a 10-hour half-life temperature of 66 ° C. or more and less than 97 ° C. A thermosetting resin composition containing an initiator is disclosed (see Patent Document 1).
JP 2005-154747 A

  According to Patent Document 1, it is said that the diffusion rate of styrene monomer and the amount of residual styrene monomer can be greatly reduced. However, even if the amount of residual styrene monomer can be reduced, the emission of formaldehyde produced from the styrene monomer cannot be reduced.

  The present invention relates to a thermosetting resin composition capable of obtaining a molded product in which the amount of styrene monomer and formaldehyde diffused into the atmosphere is reduced, and a thermosetting resin molded product obtained from the thermosetting resin composition The purpose is to provide.

  The thermosetting resin composition of the present invention is a composition containing an unsaturated polyester resin and / or vinyl ester resin, a styrenic monomer, a peroxyketal and / or peroxy ester, and a hydrazide compound. The 10-hour half-life temperature of the peroxyketal and / or peroxyester is 66 to 97 ° C., and the hydrazide compound is contained in an amount of 0.05 to 2% by mass.

  According to this configuration, when a peroxyketal and / or peroxyester having a 10-hour half-life temperature of 66 to 97 ° C. is used as a curing catalyst, the curing reaction of the thermosetting resin composition proceeds favorably. The amount of residual styrenic monomer remaining in the molded article thus obtained can be reduced.

  Moreover, when a hydrazide compound is contained in a thermosetting resin composition so that it may become 0.05-2 mass%, the formaldehyde produced | generated from a styrene-type monomer can be capture | acquired. That is, it is possible to simultaneously reduce the amount of residual styrene monomer and capture formaldehyde.

  Therefore, the thermosetting resin composition of the present invention can provide a molded product in which the amount of styrenic monomer and formaldehyde diffused into the atmosphere is reduced.

  The hydrazide compound is preferably a trihydrazide compound. Trihydrazide compounds are more effective at capturing formaldehyde. Furthermore, since the trihydrazide compound has almost no adverse effect on the curing reaction of the thermosetting resin composition, the curing reaction proceeds more suitably, and the amount of residual styrene monomer can be further reduced. Therefore, the amount of styrene monomer and formaldehyde released from the obtained molded product into the atmosphere can be reduced together.

  The hydrazide compound is preferably 1,3,5-tris (2-hydrazinocarbonylethyl) isocyanurate. With such a hydrazide compound, the amount of styrene-based monomer and formaldehyde released from the obtained molded product into the atmosphere can be further reduced.

  The peroxyketal and / or peroxyester preferably has a t-hexyl structure. With such a structure, the peroxyketal and / or peroxyester can cause the curing reaction of the thermosetting resin composition to proceed more suitably, so that the amount of residual styrene monomer remaining in the molded product can be reduced. It is possible to further reduce the amount of styrenic monomer diffused from the molded product into the atmosphere.

  The thermosetting resin composition preferably contains polystyrene as a low shrinkage agent. Since polystyrene is easily dissolved in a styrene monomer, it can sufficiently exhibit a low shrinkage effect in which molding distortion and molding shrinkage hardly occur.

  The thermosetting resin molded article of the present invention is obtained by molding and curing the thermosetting resin composition. According to this configuration, this thermosetting resin molded article enjoys the effect of the thermosetting resin composition of the present invention, and can reduce the amount of styrene monomer and formaldehyde that are diffused into the atmosphere.

  The thermosetting resin composition of the present invention provides a molded product in which the amount of styrene monomer and formaldehyde that are diffused into the atmosphere is reduced.

  The thermosetting resin composition of the present invention is a composition containing an unsaturated polyester resin and / or vinyl ester resin, a styrenic monomer, a peroxyketal and / or peroxy ester, and a hydrazide compound. The 10-hour half-life temperature of the peroxyketal and / or peroxyester is 66 to 97 ° C., and the hydrazide compound is contained in an amount of 0.05 to 2% by mass.

  The unsaturated polyester resin is obtained by polycondensation of an unsaturated polybasic acid and a polyhydric alcohol as necessary with a known method, and is known as a thermosetting resin. The type of the unsaturated polyester resin is not particularly limited. In addition, an acid anhydride is contained in unsaturated polybasic acid and saturated polybasic acid.

  Examples of the unsaturated polybasic acid include unsaturated dibasic acids such as maleic anhydride, maleic acid, fumaric acid, and itaconic acid. Examples of the saturated polybasic acid include saturated dibasic acids such as phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, and sebacic acid, and dibasic acids such as benzoic acid and trimellitic acid. Acids other than can be used.

  Examples of the polyhydric alcohol include glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, hydrogenated bisphenol, and 1,6-hexanediol. Moreover, alcohols other than glycols, such as glycerol and pentaerythritol, can also be used as needed.

  In the present invention, not only the unsaturated polyester resin but also a part or all of the unsaturated polyester resin can be replaced with a vinyl ester resin. The vinyl ester resin is also referred to as an unsaturated epoxy resin or an epoxy acrylate resin. The epoxy group of an epoxy resin having two or more epoxy groups in one molecule has an unsaturated group such as acrylic acid or methacrylic acid. A liquid resin in which a reaction product (epoxy acrylate) obtained by ring-opening addition of a basic acid or a monoester of an unsaturated dibasic acid such as maleic acid or fumaric acid is dissolved in a monomer. Can also be used.

  Here, as the epoxy resin, any known epoxy resin can be used. Specifically, bisphenol A type epoxy resin and bisphenol F type epoxy resin synthesized from bisphenol A, bisphenol F, or bisphenol S and epichlorohydrin. Or a bisphenol type epoxy resin such as a bisphenol S type epoxy resin, a phenol novolac type epoxy resin synthesized from a so-called phenol novolak resin and epichlorohydrin obtained by reacting phenol and formaldehyde in the presence of an acidic catalyst, and cresol and formaldehyde Novolac epoxy such as cresol novolac type epoxy resin synthesized from so-called cresol novolac resin and epichlorohydrin, obtained by reacting with an acidic catalyst. Butter, and the like can be mentioned.

  The styrenic monomer used in the present invention is contained for the crosslinking reaction (curing reaction) of unsaturated polyester resin and / or vinyl ester resin, and has excellent solubility in polystyrene, which will be described later. Have Examples of the styrene monomer include styrene, vinyl toluene, chlorostyrene, α-methyl styrene, t-butyl styrene, divinyl benzene, and the like. These styrenic monomers may be used alone or in combination of two or more.

  The styrenic monomer is dissolved in the unsaturated polyester resin and / or vinyl ester resin described above and the low shrinkage agent described later and blended with them, or is added as it is.

  The blending ratio of the styrenic monomer is not particularly limited and is adjusted according to reactivity, workability, and other various purposes. For example, 3 to 20% by mass is contained in the total amount in the thermosetting resin composition. It is preferred that If the amount of the styrene monomer is too small, the moldability tends to be lowered, and if the amount is too large, the amount of the styrene monomer emitted tends to increase.

  Moreover, in this invention, radical reactive monomers other than a styrene-type monomer may be included. Examples of radical reactive monomers other than styrene monomers include methyl methacrylate, methyl acrylate, ethyl acrylate, vinyl acetate, diallyl terephthalate, and the like. These radical reactive monomers may be used alone or in combination of two or more.

  The peroxyketal and / or peroxyester used in the present invention is a component contained as a curing catalyst, and is a peroxide having a 10-hour half-life temperature of 66 to 97 ° C. When cured using this curing catalyst, the curing reaction proceeds favorably, so that the amount of residual styrene monomer remaining in the obtained molded product can be reduced. In addition, since this curing catalyst has a slow activity until the thermosetting resin composition reaches a certain temperature or higher in the molding step, the resin fluidity during molding can be ensured. Further, when the 10-hour half-life temperature is less than 66 ° C., a thermosetting resin composition having a sufficient lifetime cannot be obtained, and when it exceeds 97 ° C., the amount of residual styrene monomer in the obtained molded product is large. As a result, the amount of styrene monomer released from the molded product increases.

  The 10-hour half-life temperature means a temperature necessary for the curing catalyst to be decomposed by heat and the concentration of the curing catalyst to be reduced to the initial half after 10 hours. Specifically, it refers to a temperature at which the half-life of the curing catalyst is 10 hours when a benzene solution of a curing catalyst having a concentration of 0.2 mol / liter is prepared and the curing catalyst is thermally decomposed in this benzene solution.

  The peroxyketal and / or peroxyester having a 10-hour half-life temperature of 66 to 97 ° C. preferably has a t-hexyl structure. With such a structure, the peroxyketal and / or peroxyester can cause the curing reaction to proceed more favorably, so that the amount of residual styrene monomer remaining in the molded product can be further reduced and The amount of styrene monomer to be diffused can be further reduced.

  As a peroxyketal having a t-hexyl structure (the parentheses indicate a 10-hour half-life temperature, the same applies hereinafter), 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane (86.7 ° C.), 1,1-bis (t-hexylperoxy) cyclohexane (87.1 ° C.) and the like. Examples of the peroxyester having a t-hexyl structure include t-hexylperoxy-2-ethylhexanol (69.9 ° C.), t-hexyloxyisopropyl carbonate (95.0 ° C.), and the like. Moreover, as a peroxy ester having a 10-hour half-life temperature of 66 to 97 ° C. other than the peroxy ester having a t-hexyl structure, for example, t-butyl peroxy-2-ethylhexanoate (92.1 ° C.) , T-amylperoxy-2-ethylhexanoate (70 ° C.) and the like.

  Moreover, as a curing catalyst, peroxides other than peroxyketal and peroxyester may be included. Examples of peroxides other than peroxyketal and peroxyester include ketone peroxide, hydroperoxide, diacyl peroxide, and dialkyl peroxide.

  The hydrazide compound used in the present invention is a component contained as a formaldehyde scavenger for capturing formaldehyde. In this hydrazide compound, a hydrazide group in the molecule and formaldehyde can react as shown in the following reaction formula (1). By this reaction, the hydrazide compound can capture formaldehyde, for example, formaldehyde generated from a styrene monomer. .

_{-NHNH 2 + HCHO → -NHN = CH} 2 + H 2 O (1)
The hydrazide compound is not particularly limited as long as it has a hydrazide group in the molecule, a monohydrazide compound having one hydrazide group in the molecule, a dihydrazide compound having two hydrazide groups in the molecule, and a molecule Examples thereof include a trihydrazide compound having 3 hydrazide groups in the inside, and a polyhydrazide compound having 4 or more hydrazide groups in the molecule.

As a monohydrazide compound, the monohydrazide compound represented by following General formula (2) is mentioned, for example.
R-CO-NHNH ₂ (2)
(In the formula, R represents a hydrogen atom, an alkyl group or an aryl group which may have a substituent.)

  In the general formula (2), the alkyl group represented by R may be linear or branched, but is preferably a linear saturated aliphatic alkyl group having 1 to 12 carbon atoms, such as methyl Group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and the like. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. Examples of the substituent of the aryl group include, for example, a halogen atom such as hydroxyl group, fluorine, chlorine, bromine, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, tert-butyl group, Examples thereof include a linear or branched alkyl group having 1 to 4 carbon atoms such as an iso-butyl group.

  Specific examples of the monohydrazide compound represented by the general formula (2) include, for example, lauryl hydrazide, salicylic hydrazide, form hydrazide, acetohydrazide, propionic hydrazide, p-hydroxybenzoic acid hydrazide, naphthoic acid hydrazide, 3 -Hydroxy-2-naphthoic acid hydrazide and the like.

Examples of the dihydrazide compound include carbohydrazide and a dihydrazide compound represented by the following general formula (3).
_{H 2 NHN-CO-A-} CO-NHNH 2 (3)
(In the formula, A represents an alkylene group or an arylene group.)

  In the general formula (3), examples of the alkylene group represented by A include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, and a nonamethylene group. C1-C12 linear alkylene groups, such as a decamethylene group and an undecamethylene group. Examples of the substituent for the alkylene group include a hydroxyl group. Examples of the arylene group include a phenylene group, a biphenylene group, a naphthylene group, an anthrylene group, and a phenanthrylene group. Among these, a phenylene group is preferable. Examples of the substituent for the arylene group include the same substituents for the aryl group.

  Specific examples of the dihydrazide compound represented by the general formula (3) include, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, suberic acid dihydrazide, sebacic acid dihydrazide, and dodecanediene. Dibasic acid dihydrazides such as acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, dimer acid dihydrazide, 2,6-naphthoic acid dihydrazide Can be mentioned.

  Among the dihydrazide compounds, carbohydrazide, succinic acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide are preferable.

  Specific examples of the trihydrazide compound include 1,3,5-tris (2-hydrazinocarbonylalkyl) isocyanurate such as 1,3,5-tris (2-hydrazinocarbonylethyl) isocyanurate. It is done.

  Specific examples of the polyhydrazide compound include polyacrylic hydrazide.

  Among the hydrazide compounds, dihydrazide compounds and trihydrazide compounds having a plurality of hydrazide groups that can contribute to the reaction as shown in the above reaction formula (1) are preferable, and trihydra compounds are more preferable. Since the trihydrazide compound has many hydrazide groups that can contribute to the reaction shown in the above reaction formula (1), the effect of capturing formaldehyde is higher. Furthermore, since the trihydrazide compound has almost no adverse effect on the curing reaction of the thermosetting resin composition, the curing reaction proceeds more suitably, and the amount of residual styrene monomer can be further reduced. Therefore, the amount of styrene monomer and formaldehyde released from the obtained molded product into the atmosphere can be reduced together.

  Among the trihydrazide compounds, 1,3,5-tris (2-hydrazinocarbonylethyl) isocyanurate is preferable. By using this hydrazide compound, it is possible to more effectively capture the effect that formaldehyde can be further captured, the curing reaction proceeds more suitably, and the amount of residual styrene monomer can be further reduced.

  The blending ratio of the hydrazide compound is 0.05 to 2% by mass in the total amount of the thermosetting resin composition, more preferably 0.1 to 1% by mass, and 0.25 to 0.5% by mass. More preferably it is. If the amount of hydrazide compound is too small, the effect of capturing formaldehyde tends to be reduced. If the amount is too large, a thermosetting resin composition having a sufficient lifetime tends to be difficult to obtain. Therefore, a molded product with a reduced amount of formaldehyde diffused into the atmosphere can be obtained when the blending ratio is as described above.

  The thermosetting resin composition of the present invention preferably contains a low shrinkage agent. The low shrinkage agent can compensate for cure shrinkage of the entire system that occurs during heat curing of the thermosetting resin composition. Examples of the low shrinkage agent include thermoplastic resins such as polystyrene, polymethacrylate, polyvinyl acetate, saturated polyester, styrene-butadiene rubber, polyvinyl acetate-polystyrene block copolymer, and multilayer structure polymer such as acrylic-styrene. These may be used alone or in combination of two or more. Among these, polystyrene is preferable because of its high solubility with styrene monomers as described above.

  The content of the low shrinkage agent is preferably 5 to 20% by mass, and 7 to 18% by mass with respect to the unsaturated polyester resin, vinyl ester resin, styrene monomer and low shrinkage agent (resin mixture). Is more preferable, and it is further more preferable that it is 9-16 mass%. If the content of the low shrinkage agent is too low, there is a tendency that sufficient low shrinkage hardening cannot be obtained, and if it is too high, the low shrinkage agent may be separated without dissolving in the styrene monomer, There is a tendency that the low shrinkage effect cannot be obtained, the coefficient of linear expansion is increased, and the rigidity during heating is lowered.

  Moreover, it is preferable that the thermosetting resin composition of this invention contains an inorganic filler and / or a reinforcing fiber. This is to increase the mechanical strength, dimensional stability, etc. of the molded product.

  As the inorganic filler, inorganic fillers generally used as molding materials can be used. For example, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, aluminum hydroxide, silica, alumina, clay, talc, silica sand, diatomaceous earth and the like can be mentioned. These may be used alone or in combination of two or more. Moreover, it is preferable that content of an inorganic filler is 0-400 mass parts with respect to 100 mass parts of total amounts of unsaturated polyester resin, vinyl ester resin, a styrene-type monomer, and a low shrinkage agent (resin mixture).

  Examples of reinforcing fibers include glass fibers and carbon fibers, and glass fibers having a fiber length of 1.5 to 5 mm are preferably used. When the fiber length is too short, a sufficient reinforcing effect cannot be obtained, and when it is too long, the moldability tends to be lowered. The content of the reinforcing fiber is preferably 10 to 150 parts by mass with respect to 100 parts by mass of the unsaturated polyester resin, vinyl ester resin, styrene monomer and low shrinkage agent (resin mixture).

  In the thermosetting resin composition of this invention, you may contain a mold release agent, a thickener, a pigment, etc. further as needed.

  As the release agent, release agents generally used for molding materials can be used, for example, fatty acids such as stearic acid and myristylic acid, aliphatic acid metal salts such as zinc stearate and calcium stearate. , Surfactants such as phosphate esters, carnauba wax and the like are used.

  As the thickener, those generally used for fiber reinforced plastic (FRP) materials such as BMC and sheet molding compound (SMC) can be used. For example, magnesium, calcium, zinc, strontium, etc. Divalent metal oxides, hydroxides, acrylic polymers, and the like are used. These may be used alone or in combination of two or more.

  The thermosetting resin composition of the present invention can be produced by mixing the unsaturated polyester resin and / or vinyl ester resin, styrene monomer, curing catalyst, hydrazide compound, and the like. Moreover, when a low shrinkage agent is contained, it is preferable to blend a low shrinkage agent solution obtained by dissolving a low shrinkage agent in a styrene monomer in advance. By doing so, the dispersibility in the thermosetting resin composition of the low shrinkage agent is improved, and therefore the dispersibility in the thermosetting resin molded article is improved, which is preferable. According to such a production method, a thermosetting resin composition in which a low shrinkage agent and a thermosetting resin such as an unsaturated polyester resin are uniformly dispersed is obtained.

  The thermosetting resin composition of the present invention is molded and cured by various press molding methods such as compression molding, injection molding, transfer molding and the like to obtain a thermosetting resin molded product.

  When the thermosetting resin composition of the present invention is used as an FRP material such as BMC or SMC, the thermosetting resin composition to which reinforcing fibers are added and, if necessary, a thickener is added in bulk or in a sheet For example, it is aged at 25 to 50 ° C. and thickened to obtain BMC, SMC, or the like. Thereafter, as described above, BMC and SMC can be molded and cured by a known molding method such as compression molding or injection molding to obtain an FRP molded product.

  The present invention will be described more specifically with reference to examples. The scope of the present invention is not limited by the examples.

The raw materials used in this example are summarized below.
(Resin component)
Unsaturated polyester resin: Polymer 9595 manufactured by Japan Composite Co., Ltd.
・ Vinyl ester resin: Neopole 8250H manufactured by Nippon Iupika Co., Ltd.
(Curing catalyst)
THPOC: 1,1-bis (t-hexylperoxy) cyclohexane (10 hour half-life temperature 87.1 ° C.)
THPOIC: t-hexylperoxyisopropyl monocarbonate (10 hour half-life temperature 95.0 ° C.)
TBPO: t-butylperoxy-2-ethylhexanoate (10 hour half-life temperature 92.1 ° C.)
TBPOB: t-butyl peroxybenzoate (10 hour half-life temperature 104.3 ° C.)
(Hydrazide compound)
・ CDH: Carbohydrazide (Nippon Finechem Co., Ltd.)
SDH: Sebacic acid dihydrazide (manufactured by Nippon Finechem Co., Ltd.)
IDH: Isophthalic acid dihydrazide (manufactured by Nippon Finechem Co., Ltd.)
HCIC: 1,3,5-tris (2-hydrazinocarbonylethyl) isocyanurate (manufactured by Nippon Finechem)
(Inorganic filler)
・ Calcium carbonate (reinforcing fiber)
・ Glass fiber (RESO3BM5 manufactured by Nippon Glass Fiber Co., Ltd., fiber length 3mm)
(Low shrinkage agent and styrene monomer)
As the low shrinkage agent, polystyrene (CJ3947 manufactured by Matsushita Electric Works Co., Ltd.) dissolved in styrene monomer (styrene) at a concentration of 30% by mass (30% styrene solution of polystyrene) was used.

  Examples 1-8 and Comparative Examples 1-3 added each component in the ratio shown in Table 1, and mixed at 25-30 degreeC with a kneader for 20-40 minutes, and obtained the thermosetting resin composition. .

[Styrene monomer concentration and formaldehyde concentration]
The thermosetting resin compositions obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were molded by the following method, and the styrene monomer concentration and the formaldehyde concentration were evaluated by the Tedra bag method.

  As the test piece, a test piece mold having a cavity of a test piece shape (70 × 40 × 3 mm) was used, and the mold temperature was 150 ° C., the injection pressure was 5 MPa, the injection time was 30 seconds, the mold clamping pressure was 5 MPa, and the mold clamping time was 120. It was created by performing transfer molding under molding conditions for a second.

  And it measured based on TSM0505G (automobile interior material evaluation method) using the obtained said test piece.

That is, a certain amount of clean air is injected into a tedra bag containing a test piece, the tedra bag is then heat-treated, the air in the tedra bag is collected in a solid phase, and the amount of styrene monomer and formaldehyde released from the collected gas. Each was analyzed.
・ Tedora bag volume: 10L
-Heating conditions: 65 ° C x 2 hours-Collection flow rate: 167 mL / min-Collection amount: 1000 mL / min-Collection tube: TenaxTA (manufactured by Spelco)
[Curing time]
Moreover, the 140 degreeC hardening time (cure time) of the thermosetting resin composition obtained in Examples 1-8 and Comparative Examples 1-3 was measured with the following method.

  A thermocouple sensor is sandwiched in the center of the thermosetting resin composition, placed in the center of a press mold set at a mold temperature of 140 ° C, and then immediately clamped to perform heat and pressure molding, and recording The internal temperature-time curve of the material as shown in FIG. Then, after the temperature starts to rise, the gelation end point 3, which is the intersection of the first tangent line 1 and the second tangent line 2, is reached, and further, the temperature rise almost stops after the temperature starts to rise. The time to reach was taken as the cure time.

  The evaluation results are shown in Table 1, respectively.

As can be seen from Table 1, a thermosetting resin containing a peroxyketal and / or peroxyester having a 10-hour half-life temperature of 66 to 97 ° C. and containing 0.05 to 2% by mass of a hydrazide compound as a curing catalyst. Molded articles obtained from the composition (Examples 1 to 8) had a styrene monomer concentration of 1000 μg / m ³ or less, a small amount of styrene monomer emitted from the molded article, and a formaldehyde concentration of 5 μg / m ^3. The amount of formaldehyde released from the molded product was also small.

  On the other hand, the molded article (Comparative Example 1) obtained from the thermosetting resin composition containing a curing catalyst having a 10-hour half-life temperature exceeding 97 ° C. is a styrene monomer as compared with Examples 1-8. The concentration was very high. Also, a molded product obtained from a thermosetting resin composition containing no hydrazide compound (Comparative Example 2) and a molding obtained from a thermosetting resin composition having a hydrazide compound content of less than 0.05% by mass. The product (Comparative Example 3) had a very high formaldehyde concentration compared to Examples 1-8.

  From these results, it was found that Examples 1 to 8 can reduce both the amount of styrene monomer and formaldehyde released into the atmosphere.

  Further, by comparing Example 1 and Example 4 which differ only in the type of hydrazide compound, Example 4 using a trihydrazide compound as the hydrazide compound is more styrene monomer concentration than Example 1 using a dihydrazide compound. Was low.

  As can be seen from the fact that the 140 ° C. curing time of Example 4 is shorter than that of Example 1, when a trihydrazide compound is used as the hydrazide compound, the curing reaction can proceed suitably, and the amount of residual styrene monomer is reduced. This is thought to be due to the reduction.

An example of the internal temperature-time curve obtained by evaluation of 140 degreeC hardening time is shown.

Explanation of symbols

1 First tangent 2 Second tangent 3 Gelation end point 4 Curing end point

Claims (6)

A composition containing an unsaturated polyester resin and / or vinyl ester resin, a styrenic monomer, a peroxyketal and / or peroxy ester, and a hydrazide compound,
The 10-hour half-life temperature of the peroxyketal and / or peroxyester is 66-97 ° C.,
A thermosetting resin composition comprising 0.05 to 2% by mass of the hydrazide compound.   The thermosetting resin composition according to claim 1, wherein the hydrazide compound is a trihydrazide compound.   The thermosetting resin composition according to claim 1, wherein the hydrazide compound is 1,3,5-tris (2-hydrazinocarbonylethyl) isocyanurate.   The thermosetting resin composition according to claim 1, wherein the peroxyketal and / or peroxyester has a t-hexyl structure.   The thermosetting resin composition according to any one of claims 1 to 4, comprising polystyrene as a low shrinkage agent.   A thermosetting resin molded article obtained by molding and curing the thermosetting resin composition according to any one of claims 1 to 5.

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