JP2000204117A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition directly usable for molded products of various thicknesses and useful for producing acrylic resin molded products of high hardness degree uniform in their thickness direction with excellent appearance, durability, heat resistance and impact resistance, etc. SOLUTION: This thermosetting resin composition comprises (A) a syrup prepared by dissolving (a3) an alkyl methacrylate homopolymer and/or copolymer in (a1) an alkyl methacrylate or (a2) an α, β-ethylenically unsaturated monomer mixture consisting mainly of the component a1, (B) a compound having at least two (meth)acryloyl groups, (C) a peroxide, and (D) an inorganic filler; wherein the component C is a peroxide consisting mainly of a peroxyketal having an exothermic peak at >=110 deg.C but <130 deg.C, with an active oxygen content of 0.05-0.2 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting composition mainly composed of a syrup containing an alkyl methacrylate monomer and a polymer thereof, and a composite of an inorganic filler and a thermosetting molding material comprising the same. . In detail, the present invention is a thermosetting composition that is excellent in moldability, is excellent in durability and physical properties because the degree of cure is uniform in the thickness direction, and is capable of producing a high-quality molded product, And a thermosetting molding material comprising the same.

[0002]

2. Description of the Related Art Acrylic resins have been used in a wide range of fields as lighting covers, automobile parts, optical parts such as lenses and prisms, etc. due to their excellent weather resistance and excellent transparency. Furthermore, in recent years, along with the expansion of the acrylic resin market, applications have been developed as interior materials for building materials, etc.
For example, acrylic artificial marble has been developed. Acrylic artificial marble is usually prepared by mixing a polymerizable viscous liquid mainly composed of methyl methacrylate, an inorganic filler such as aluminum hydroxide, a decorative material, and a polymerization initiator, and using a cell casting method or a continuous casting method. A product manufactured by polymerizing and solidifying into a plate shape and then cutting it into a desired size is commercially available as a product. Specific applications of these acrylic artificial marble products include top plates, doors and walls for system kitchens, top plates for vanities, toilet booths, waist walls and aprons for unit baths, and bay window counters.

[0003] However, when artificial marble is used as a member in these applications, commercially available acrylic artificial marble can only be processed into a single curved surface of 50R or more by heating. However, there is a problem that complicated secondary processing steps such as cutting, bonding, and polishing must be performed. Also, with the spread of acrylic artificial marble, its high design has been evaluated, and the demand for irregular shaped products such as washbasins and bathtubs has been increasing. There was a problem that the request could not be met.

[0004] From such a background, for example, Japanese Patent Application Laid-Open
According to 3899, an acrylic BMC is proposed, but as the thickness of the molded article increases, the degree of curing decreases, or the distribution of the degree of curing in the thickness direction is increased. Durability and strength may be poor,
There are problems such as difficulty in manufacturing molded articles of various thicknesses with the same catalyst composition, and at present, sufficiently satisfactory results have not been obtained.

Acrylic artificial marble has been highly evaluated for its high-grade appearance and design, but on the other hand, it has a problem that it is brittle and vulnerable to impact because of its crosslinked structure. .

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a molded article having various thicknesses without a great influence on the degree of curing even if the thickness of the molded article changes. An object of the present invention is to provide a thermosetting resin composition capable of producing an acrylic resin molded article having a high degree of uniform curing in the thickness direction and excellent properties such as appearance, durability, heat resistance, and impact resistance. .

[0007]

As a result of repeated studies to achieve the above object, alkyl methacrylate, a mixture of α, β-ethylenically unsaturated monomers containing alkyl methacrylate as a main component, and alkyl methacrylate A polymerizable resin selected from alkyl methacrylate syrups in which the unified and / or alkyl methacrylate copolymer is dissolved in an alkyl methacrylate or in a mixture of α, β-ethylenically unsaturated monomers containing alkyl methacrylate as a main component; In a thermosetting resin composition comprising a compound having two (meth) acryloyl groups, a peroxide, and an inorganic filler, the peroxide mainly comprises a peroxyketal having a specific exothermic peak temperature. Use oxides and include them in the composition in certain proportions By doing so, it is possible to achieve uniform curing in the thickness direction and improve various properties such as appearance, durability, heat resistance and the like. The inventors have found that the impact strength can be remarkably improved, and have completed the present invention.

That is, the present invention relates to (a1) an alkyl methacrylate, (a2) an α, β-ethylenically unsaturated monomer mixture containing alkyl methacrylate as a main component, and (a3) an alkyl methacrylate homopolymer and / or
Or a polymerizable resin raw material (A) selected from alkyl methacrylate syrups in which an alkyl methacrylate copolymer is dissolved in an alkyl methacrylate or an α, β-ethylenically unsaturated monomer mixture containing an alkyl methacrylate as a main component; In a thermosetting resin composition comprising a compound (B) having at least two (meth) acryloyl groups, a peroxide (C), and an inorganic filler (D), the peroxide (C) is 110 ° C or higher. A peroxide containing a peroxyketal as a main component having an exothermic peak of less than 130 ° C., and the amount of the peroxide (B) added to the polymerizable resin material (A) and at least two (meth) acryloyl The thermosetting resin composition has an active oxygen content of 0.05 to 0.2% based on the total amount of the compound having a group (B).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the thermoplastic resin composition of the present invention, (a1) alkyl methacrylate, (a)
2) α, β-ethylenically unsaturated monomer mixture containing alkyl methacrylate as a main component [hereinafter referred to as “α, β-
Ethylenically unsaturated monomer mixture (a2) "), or (a3) an alkyl methacrylate homopolymer and / or an alkyl methacrylate copolymer in an alkyl methacrylate or containing an alkyl methacrylate as a main component. Alkyl methacrylate syrup [hereinafter sometimes referred to as “alkyl methacrylate syrup (a3)”] dissolved in a β-ethylenically unsaturated monomer mixture is used.

The alkyl methacrylate used in the alkyl methacrylate (a1) or the α, β-ethylenically unsaturated monomer mixture (a2) constituting the polymerizable resin raw material (A), and an alkyl methacrylate syrup (a3)
As the alkyl methacrylate used to dissolve the homopolymer and / or the copolymer of the alkyl methacrylate, an alkyl ester of methacrylic acid having 1 to 15 carbon atoms is preferably used. Specific examples thereof include methyl methacrylate and ethyl methacrylate. , N-propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate and the like, and one or more of these alkyl methacrylates can be used. Among them, as the alkyl methacrylate used in the polymerizable resin raw material (A), a lower alkyl ester of methacrylic acid having 1 to 4 carbon atoms is more preferable, and methyl methacrylate is particularly preferable.

When the polymerizable resin raw material (A) is the above-mentioned α, β-ethylenically unsaturated monomer mixture (a2) or alkyl methacrylate syrup (a3), other α-β may be used in combination with alkyl methacrylate. Specific examples of the .beta.-ethylenically unsaturated monomer include methyl acrylate,
Alkyl acrylates such as ethyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, and cyclohexyl acrylate;
Hydroxyalkyl (meth) such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-chloropropyl methacrylate, 2-hydroxy-3-chloropropyl acrylate Acrylate; acrylic acid; methacrylic acid; metal (meth) acrylate; vinyl chloride; vinyl acetate; acrylonitrile;
Styrene monomers such as α-methylstyrene; vinyl toluene, acetic anhydride and the like. One or more of these monomers can be used in combination with one or more of alkyl methacrylates.

The α, β-ethylenically unsaturated monomer mixture (a2) and the α, β-ethylenically unsaturated monomer mixture mainly composed of alkyl methacrylate used for the alkyl methacrylate syrup (a3) The content ratio of the alkyl methacrylate is preferably 50 mol% or more based on the total number of moles of the monomer mixture.
More preferably, it is at least mol%. Among them,
The proportion of methyl methacrylate accounts for at least 50 mol%, especially at least 60 mol%, based on the total moles of the monomer mixture, of alkyl methacrylate other than methyl methacrylate and / or other α, β-ethylenically unsaturated monomer. From the viewpoint of durability, it is more preferable to use a monomer mixture having a monomer content of 50 mol% or less, particularly 40 mol% or less.

When the polymerizable resin raw material (A) is an alkyl methacrylate syrup (a3), it is dissolved in an alkyl methacrylate or a mixture of α, β-ethylenically unsaturated monomers containing alkyl methacrylate as a main component. The alkyl methacrylate homopolymer or the alkyl methacrylate copolymer is a methacrylic acid alkyl ester having 1 to 15 carbon atoms, and among them, a homopolymer of methacrylic acid having a lower alkyl ester having 1 to 4 carbon atoms or a mixture thereof. And a copolymer of α, β-ethylenically unsaturated monomer, and a homopolymer of methyl methacrylate or an alkyl methacrylate other than methyl methacrylate and methyl methacrylate and / or
Alternatively, a copolymer with another α, β-ethylenically unsaturated monomer is particularly preferable from the viewpoint of durability.

Other α, β-ethylenically unsaturated monomers that can constitute the alkyl methacrylate copolymer include:
As specific examples of the α, β-ethylenically unsaturated monomer, various monomers similar to those described above can be used.
As the alkyl methacrylate homopolymer or the copolymer of alkyl methacrylate and another α, β-ethylenically unsaturated monomer used in the alkyl methacrylate-based syrup (a3), those having a polymerization degree of about 800 to 2,000, It is preferably used in terms of controlling the fluidity and curability of the syrup.

Alkyl methacrylate syrup (a)
3) has a viscosity of 0.1 to 500 poise at 25 ° C., and has an alkyl methacrylate homopolymer and / or
Alternatively, the content of the alkyl methacrylate-based copolymer is preferably 3 to 70% by weight, particularly preferably 20 to 70% by weight.
It is preferably 60% by weight. When the content ratio of the alkyl methacrylate homopolymer and / or the alkyl methacrylate copolymer in the alkyl methacrylate syrup (a3) is less than 3% by weight, shape retention as a molding material is deteriorated and stickiness occurs. However, when the content exceeds 70% by weight, the viscosity of the syrup becomes too high, so that stirring becomes difficult and the problem that the productivity is lowered is apt to be caused.

The poly (meth) acryloyl compound in the present invention is represented by the formula: CH ₂ ＣC (R ¹ ) COO— (wherein R ¹ represents a hydrogen atom or a methyl group). A) a compound having two or more acryloyl groups in one molecule, and any poly (meth) acryloyl compound having two or three or more (meth) acryloyl groups can be used.

Among them, poly (meth) acryloyl compounds having two (meth) acryloyl groups are generally represented by the following formula (1): CH ₂ ＣC (R ¹ ) COO-R ² -OOC (R ¹ ) C ＝ CH ₂ (1) (wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents a divalent organic group). In the above formula (1), the molecular weight of the organic radical ^{R 2} is is preferably 2000 or less.

[0018] Preferred examples of poly (meth) acryloyl compound represented by the formula (1), groups ^{R 2,} wherein: -C
_{2 H 4 - (OC 2 H} 4) m - ( wherein m is preferably 0
Ethylene group or represented by 23) (poly) ethylene oxide group of the _{formula: -C 3 H 6 - (OC} 3 H 6) n - ( propylene group wherein n is preferably represented by 0 to 7) or (poly) propylene oxide group, the formula: _-C 4 _{H 8} -
(OC ₄ H ₈ ) _p- (wherein p is preferably 0 to 7), a butylene group or a (poly) butylene oxide group, formula: —C ₆ H ₁₂ — (OC ₆ H ₁₂ ) _q — ( Where q
Is preferably an alkylene group such as a hexylene group or a (poly) hexylene oxide group, a neopentyl group, or a polyalkylene oxide group represented by 0 to 7); 2,2-bis [4- (methacryloxy) phenyl] propane, 2,2-bis compound group ^{R 2,} such as [4- (methacryloxy ethoxy) phenyl] propane having an aromatic nucleus; 1,4-bis (methacryloxy methyl)
Group R ^2, such as cyclohexane and the like compounds are alicyclic group.

Further, in the poly (meth) acryloyl compounds represented by the above formula (1), the divalent organic group R ² may be a group produced by urethane-forming reaction, such groups R ² Examples of the poly (meth) acryloyl compound having the formula (I) include di (meth) acryloyl polyurethane obtained by the reaction of hydroxy (meth) acrylates, diols and diisocyanates. Examples of preferred diols that can be used at that time include poly (propylene oxide) diol, poly (ethylene oxide) diol, copoly (ethylene oxide-propylene oxide) diol, hydroxyethoxylated bisphenol A, hydroxyethoxylated bisphenol S, Examples include spiro glycol and carbonate diol. Examples of diisocyanates include tolylene diisocyanate, 4,4-
Examples include diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene bis (cyclohexyl isocyanate), and trimethylhexamethylene diisocyanate.

Examples of the compound having three or more (meth) acryloyl groups include trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, and tetramethylol methane tetraacrylate. It is also possible to use these trifunctional or higher poly (meth) acryloyl compounds.

One or more of these poly (meth) acryloyl compounds can be used, and the amount of the compound is preferably 0.05 to 50 parts by weight per 100 parts by weight of the polymerizable resin raw material (A). And particularly preferably 0.1 to 3
It is preferably 0 parts by weight. When the amount is less than 0.05 parts by weight, properties such as heat resistance may not be sufficiently exhibited, or it may be difficult to release from a mold at the time of forming a different shape, and on the other hand, more than 50 parts by weight. In such a case, long-time polymerization is required, and thus problems such as deterioration in productivity and deterioration in weather resistance may occur, which is not preferable.

In the present invention, the total amount of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups is from 110 ° C. to 13 ° C.
A peroxide (C) containing peroxyketal (c1) as a main component having an exothermic peak temperature of less than 0 ° C. is added at a ratio of 0.05 to 0.2% as an active oxygen amount. If the amount of the peroxide (B) is less than 0.05%, the degree of curing of the molded article will not be sufficiently high, and thus the molded article will be deformed when it is released from the mold, If the strength is insufficient, while if it exceeds 0.2%, the cured state becomes poor, so that cracks tend to occur at the center of the thickness of the molded product, resulting in poor appearance.

Here, the exothermic peak temperature of the peroxide in the present invention means that the peroxide (C) is a polymerizable resin raw material (A) and a compound (B) having at least two (meth) acryloyl groups. , The temperature when added to the mixture of the inorganic filler (D) and measured as described below,
The amount of active oxygen of peroxide relative to a mixture of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups refers to the amount calculated as follows.

Measurement of the exothermic peak temperature of the peroxide: The peroxide (C) was converted into a polymerizable resin raw material (A), a compound (B) having at least two (meth) acryloyl groups, and an inorganic filler (D). To the mixture of (1), a peroxide having an active oxygen content of 0.193% was added to prepare a sample. The sample was filled in a closed aluminum pan (3 mg), and DSC (Mac Science 3100) was used. 10 from room temperature to 250 ° C
The temperature at which the calorific value shows the maximum value when the temperature is raised at a rate of ° C / min is defined as the exothermic peak.

The polymerizable resin raw material (A) and at least two
Mixing with compound (B) having (meth) acryloyl group
Active oxygen content of peroxide with respect to the product : Peroxide activity per 1 kg of a mixture of the resin component (A) and the compound (B) having at least two (meth) acryloyl groups according to the following formula (2): Calculate the oxygen content (%).

Active oxygen content (%) = Pu × {(No × 16) / Mn} (2) where Pu = purity of peroxide (%) No = peroxide-O—O— bond Number Mw = molecular weight of peroxide The peroxyketal (c1) used in the present invention is generally represented by the following formula (3).

[0027]

Embedded image

[0028] ^(wherein, R ^3, R 4, ^{R 5} and ^{R 6} each independently represent an alkyl group, a cycloalkyl group, a hydrocarbon group such as an aryl group, ^{R 3} and ^{R 4} are bonded to each other (A divalent cyclic hydrocarbon group may be formed, and R ⁵ and R ⁶ are preferably a t-butyl group.)

In the present invention, of the peroxyketal represented by the above formula (3), its exothermic peak temperature is 11
It is necessary to use one having a temperature of 0 ° C. or more and less than 130 ° C., and by using such a specific peroxide in a specific amount, the amount of the residual monomer in the final molded article is extremely small, and it is sufficiently cured. Thus, a molded article having excellent physical properties such as strength, heat resistance and durability can be obtained, and even if the thickness of the produced molded article changes, such excellent properties are not impaired. On the other hand, when a peroxyketal having an exothermic peak temperature out of the range of 110 ° C. or more and less than 130 ° C. is used, the amount of the residual monomer in the final molded article is increased and the molding is sufficiently cured. A product cannot be obtained, and the degree of curing varies depending on the thickness of the molded product, resulting in inferior physical properties such as strength, heat resistance and durability of the molded product. Preferred examples of the peroxyketal (c1) having an exothermic peak temperature of 110 ° C. or higher and lower than 130 ° C. include 1,1-t-butylperoxy-3,3,5-trimethylcyclohexane and 2,2-di (t -Butylperoxy) butane, and it is preferable to use a mixture of any one or both of them.

In the present invention, as the peroxide (C), the amount of peroxyketal (c1) is 0.1% by the amount of active oxygen.
When the mixture of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups is cured by using together with the peroxyketal (c1) in an amount of 09 to 0.11%, A peroxide (c2) having an exothermic peak of 90 ° C. or more and less than 110 ° C., from 0 to 0.006%, preferably 0 to 0.004%, a peroxide having an exothermic peak of 130 ° C. or more and less than 140 ° C. c3) from 0 to 0.06%,
Preferably 0.004 to 0.06%, 140 ° C. or higher 17
A peroxide (C4) having an exothermic peak below 0 ° C.
In the case where a peroxide containing 0.06%, preferably 0.004 to 0.06%, is used, even if the thickness of the molded article is as thick as 10 mm, for example, the thermosetting property is high. The same thermosetting resin composition without changing the type and composition of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups in the resin composition for each thickness of the molded article By using the above, it is possible to obtain a sufficiently cured good molded product having almost the same degree of curing and other physical properties.

The peroxide (c2) may be any one as long as its exothermic peak temperature is 90 ° C. or higher and lower than 110 ° C., and the type thereof is not limited. Examples of the peroxide (c2) satisfying such conditions include t-butyl peroxy neodecanoate, di-3-methoxybutyl peroxy dicarbonate, di-2-ethylhexyl peroxy dicarbonate, bis ( 4-t-butylcyclohexyl) peroxydicarbonate, t-hexylperoxy neodecanoate, 2,4,4-trimethylpentylperoxy-2-neodecanoate, and the like.
When a peroxide (c2) of 0.006% or less is used together with the peroxyketal (c1), the peroxide (c2) is used before the reaction in which the calorific value of the peroxyketal (c1) is maximized. Is generated, the amount of heat generated can be dispersed over time so that excessive heat is not generated at one time, and until the mold is completely filled with the thermosetting resin composition (molding material). And the start time of the curing reaction can be adjusted, so that molding can be performed smoothly.

The peroxide (c3) which can be used in combination with the peroxyketal (c1) may be any peroxide as long as its exothermic peak temperature is from 130 ° C. to less than 140 ° C. Is not limited. Examples of the peroxide (c3) satisfying such conditions include t-butylperoxy-3,5,5-trimethylhexanoate,
Examples thereof include t-butyl peroxyisopropyl carbonate, cyclohexanone peroxide, t-butyl peroxybenzoate, t-butyl peroxy acetate, and the like.

The peroxide (c4) which can be used in combination with the peroxyketal (c1) may be any peroxide as long as its exothermic peak temperature is 140 ° C. or more and less than 170 ° C. There is no particular limitation. Preferred peroxides (c4) satisfying such conditions include 1,1
3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, t-butylcumyl peroxide,
2,5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butyl peroxide,
4,4-trimethylpentyl-2-hydroperoxide and the like can be mentioned. Peroxyketal (c
1) together with the peroxide (c) at an active oxygen content of 0.06% or less.
When 3) and the peroxide (c4) are used in combination, the degree of curing can be increased when a molded article having a thickness of about 10 mm or more is produced using the thermosetting tree composition of the present invention. it can.

In the present invention, the inorganic filler (D) is not particularly limited, and examples thereof include aluminum hydroxide, magnesium hydroxide, calcium carbonate, silica, and frit glass. From the viewpoint, aluminum hydroxide and frit glass are preferably used. The amount of the inorganic filler added is 100 in total of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups in the thermosetting resin composition.
The amount is preferably from 30 to 200 parts by weight, particularly preferably from 60 to 150 parts by weight, based on parts by weight. When the amount of the inorganic filler is less than 30 parts by weight, volumetric shrinkage due to polymerization is increased, and dimensional stability may be deteriorated. On the other hand, when the amount is more than 200 parts by weight, the mechanical strength of the molded product is reduced. Problems such as lowering tend to occur, which is not preferable.

By adding a resin having a glass transition temperature of 25 ° C. or lower to the thermosetting resin composition of the present invention, a molding material having improved impact strength can be obtained. The resin having a glass transition temperature of 25 ° C. or lower is not particularly limited, and examples thereof include polybutadiene, polyisoprene,
Butadiene-isoprene copolymer, polychloroprene,
Conjugated diene polymers such as styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylate-butadiene copolymer; hydrogenated products of the diene polymers; ethylene-propylene copolymer, ester-propylene Olefin rubbers such as diene copolymers, ethylene-vinyl acetate copolymer rubbers and polyisobutylene rubbers; acrylic rubbers; fluoro rubbers; thermoplastic elastomers such as polyurethane elastomers, polyester elastomers, polyamide elastomers, and the above polymers. Examples thereof include a polymer having a multilayer structure as a rubbery polymer layer, and one or more of these polymers can be used.

The amount of these polymers is preferably 1 to 100 parts by weight based on the total of 100 parts by weight of the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups. Not more than 5 parts by weight, particularly preferably 5 parts by weight
The amount is preferably not less than 30 parts by weight and not more than 30 parts by weight. If the amount of the polymer is less than 1 part by weight, the effect of improving impact resistance may not be exhibited, while if it exceeds 100 parts by weight, various physical properties such as surface hardness, chemical resistance, weather resistance and the like. Is sometimes reduced, which is not preferable.

The thermosetting resin composition of the present invention may further comprise, if necessary, an ultraviolet absorber, a light stabilizer, an antioxidant, an organic or inorganic coloring dye, resin granules, or natural stone granules. Other additives such as a pattern material such as an object, an organic or inorganic short fiber, a filler, another resin of a different kind, and the like can be added as long as the object of the present invention is not impaired. The method for producing the thermosetting resin composition of the present invention is not particularly limited, and any method can be adopted as long as the above-mentioned components can be uniformly added and mixed.

In producing a molded article using the thermosetting resin composition of the present invention, the thermosetting resin composition of the present invention is filled in a mold which has been heated to a predetermined temperature in advance and heated. A compression molding method in which pressure is applied is preferably used, but the method is not limited thereto, and other methods such as injection molding and transfer molding can be employed.

The molded article obtained from the thermosetting resin composition of the present invention and a molding material comprising the thermosetting resin composition has a high degree of curing, has a uniform degree of curing in the thickness direction, and has a high degree of curing. Excellent appearance, durability, heat resistance, excellent strength,
Suitable for molding materials such as counters, washstands, washbasins, washbasins, bathtubs, etc. in the interior of building materials, especially by giving them a marble-like appearance, because they have excellent impact resistance and can be deformed by deep drawing etc. Can be used.

[0040]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited thereto. In the following examples, the one-minute half-life temperature of the peroxide was determined by using the catalog value of the manufacturer, and the ratio of residual monomer content to polymerization rate in the molded product was measured as follows.

Polymerization ratio (%) in molded article : 10 mg of the thermosetting resin composition before molding was filled in a closed aluminum pan, and the temperature was increased from room temperature to 250 ° C. using DSC (Model 3100, manufactured by Mac Science) at 10 ° C. The total calorific value per unit amount when the temperature is raised at a rate of / min is defined as ε. Next, assuming that the total calorific value per unit amount when the sample after molding and curing is measured in the same manner is ζ, the polymerization rate is represented by the following formula 4. Polymerization rate (%) of molded article = ζ × 100 / ε (4)

Test Example 1 Measurement of the exothermic peak temperature and 1-minute half-life temperature of peroxide (1) Polymerizable mixed liquid (A1) 60 comprising 70% by weight of methyl methacrylate and 30% by weight of neopentyl glycol dimethacrylate 40% by weight of Parabeads EH (manufactured by Kuraray Co., Ltd.) was added to the weight%, and the mixture was stirred in a hot water bath at 60 ° C. for 2 hours to obtain a viscous syrup (A). To 60% by weight of this syrup (A), 40% by weight of aluminum hydroxide (CWL-308S manufactured by Sumitomo Chemical Co., Ltd.) was added, and 10% was added using a plast mill (manufactured by Toyo Seiki Co., Ltd.).
After kneading for minutes, a clay-like polymerizable composition (E) was obtained. (2) Each peroxide is independently added to the polymerizable mixed liquid (A1) contained in the polymerizable composition (E) obtained in (1) above at a rate of 0.2% of active oxygen, After stirring with a plastmill (manufactured by Toyo Seiki Co., Ltd.) for 10 minutes, the exothermic peak temperature of the polymerizable composition (E) upon heat curing was measured. Table 1 also shows the one-minute half-life temperatures of the peroxides described in the catalogs of the manufacturers.

[0043]

[Table 1]

In general, the one-minute half-life temperature of peroxide is widely used as a standard for the curing reaction temperature and curing reactivity of a polymer with a peroxide, but it is clear from the results in Table 1 above. In addition, the actual activation temperature (exothermic peak temperature) when the peroxide is mixed with the polymerizable composition (E) does not always coincide with the one-minute half-life temperature. The one-minute half-life temperature cannot be used as a standard for the curing reaction of the polymerizable composition (E), and the exothermic peak is employed. According to the present invention, the specific temperature more suitable for the curing reaction of the polymerizable composition (E) This makes it possible to select the type of peroxide and determine the amount of addition.

<< Examples 1 and 2 >> The exothermic peak temperature of 110 ° C. or more and less than 130 ° C. as the peroxide (C) was added to the polymer composition (E) produced in the same manner as in the above Test Example (1). Peroxyketal having an active oxygen content of 0.1%
To obtain a thermosetting resin composition. (2) The thermosetting resin composition 400 obtained in the above (1)
g is heated to 130 ° C. in advance, and is a box-shaped molded product with a collar (collar: outer size: 176 mm × 146 mm, inner size: 15
0 mm x 120 mm, thickness 8 mm, height 51 mm, rising wall: thickness 3.5 mm, bottom in box: 144 mm x
(114 mm, bottom thickness: 8 mm) was obtained, and after holding for 5 minutes at a molding pressure of 80 kg / cm ^{2 with} respect to the projected area of the molded product, the mold was opened to obtain a molded product. (3) One sample was taken from the bottom of the molded product obtained in (2) above.
0 mg was sampled, and the polymerization rate of the molded article was measured by the above method. As a result, a high polymerization rate was achieved as shown in Table 2.

Comparative Examples 1 to 8 Peroxyketals having an exothermic peak temperature of less than 110 ° C. or 130 ° C. or more, and substances other than peroxyketals having an exothermic peak temperature of 110 ° C. to less than 130 ° C. are used as peroxides. Except for the above, a molded article was prepared in the same manner as in Example 1 and the polymerization rate was measured. As shown in Table 2, the degree of curing was low and sufficient curing was not performed.

[0047]

[Table 2]

Examples 3 and 4 The polymerization composition (E) produced in the same manner as in Test Example (1) was added with 1,1-t-butylperoxy-peroxyketal (c1).
3,3,5-trimethylcyclohexane, 2,4,4-trimethylpentylperoxy-2-neodecanoate as peroxide (c2), t-butylperoxyisopropyl carbonate as peroxide (c3), peroxide A thermosetting resin composition was prepared by using 1,3-bis (t-butylperoxyisopropyl) benzene as the product (c4) and adding each at the ratio shown in Table 3 below. (2) The thermosetting resin composition obtained in (1) was used in Example 1.
(2) to obtain a molded article. (3) Example 1 of the molded article obtained in (2)
As a result of measuring the polymerization rate in the same manner as (3), as shown in Table 3, a higher polymerization rate was achieved than when peroxyketal (c1) was used alone.

Comparative Examples 9 to 13 Molded articles were prepared in the same manner as in Example 2 except that the addition amounts of the peroxyketal (c1) and the peroxides (c2 to c4) were changed, and the polymerization rate was determined. As a result of the measurement, as shown in Table 3, the degree of curing was low, and sufficient curing was not performed.

[0050]

[Table 3]

<< Examples 5 to 7 >> (1) The polymerization composition (E) produced in the same manner as in Test Example (1) above was added with 1,1-t-butyl peroxyketal (c1). Oxy-3,3,5-trimethylcyclohexane is 0.093% in terms of active oxygen, 0.050% of t-butylperoxyisopropyl carbonate as peroxide (c3), and 1,3 as peroxide (c4). -Bis (t-butylperoxyisopropyl) benzene was added in an amount of 0.050%, and a resin component having a glass transition temperature of 25 ° C. or lower as shown in Table 4 was polymerized in the polymerizable composition (E). 10% by weight was added to the resin raw material (A) to prepare a thermosetting resin composition. (2) The thermosetting resin composition obtained in (1) was used in Example 1.
(2) to obtain a molded article. (3) As a result of performing a fracture toughness test on a sample cut from the bottom of the molded body obtained in (2) in accordance with ASTM D5045-91, values shown in Table 4 were obtained.

Comparative Example 14 A molded product was prepared in the same manner as in Example 4 except that a resin component having a glass transition temperature of 25 ° C. or lower was not added, and the fracture toughness was measured.
The values shown in Table 4 were obtained.

[0053]

[Table 4]

[0054]

The thermosetting resin composition of the present invention has no significant effect on the degree of curing even if the thickness of the molded article changes, and can be used as it is for molded articles of various thicknesses. An acrylic resin molded product having a high degree of curing and having a uniform degree of curing in the thickness direction and having excellent properties such as appearance, durability, heat resistance and impact resistance can be produced.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BG051 DE078 DE148 DE238 DJ018 DL008 EH076 EH106 EK007 EK057 EK067 EK077 EK087 FD018 FD147 FD206 4J011 BB01 BB02 BB06 BB10 GA01 GA05 GB02 GB07 4J015 BA03Q04 AB03 AB04 AB04R AC03Q AC03R AG04Q AG04R AJ02Q AJ02R AK01Q AK01R AL03P AL03Q AL03R AL04P AL04Q AL04R AL05P AL05Q AL05R AL08P AL08Q AL08R AL09Q AL09R AM02Q AM02R AM15Q AM15R BA03Q BA03RBC04BC01 BC01

Claims (4)

[Claims] (A1) alkyl methacrylate, (a)
2) an α, β-ethylenically unsaturated monomer mixture containing alkyl methacrylate as a main component, and (a3) an alkyl methacrylate homopolymer and / or an alkyl methacrylate-based copolymer in an alkyl methacrylate or containing an alkyl methacrylate as a main component A polymerizable resin material (A) selected from alkyl methacrylate syrups dissolved in an α, β-ethylenically unsaturated monomer mixture, a compound (B) having at least two (meth) acryloyl groups, In the thermosetting resin composition comprising the oxide (C) and the inorganic filler (D), the peroxide (C) is mainly composed of a peroxyketal having an exothermic peak of 110 ° C. or more and less than 130 ° C. Oxides,
And the amount of peroxide (B) added is such that the polymerizable resin raw material (A)
With respect to the total amount of the compound (B) having at least two (meth) acryloyl groups and 0.0
A thermosetting resin composition of 5 to 0.2%. 2. The peroxide (C) has a temperature of 110 ° C. or more and 130
Peroxyketal (c) having an exothermic peak of less than
1) When curing the polymerizable resin raw material (A) and the compound (B) having at least two (meth) acryloyl groups in combination with the peroxyketal (c1), 9
A peroxide (c2) having an exothermic peak temperature of 0 ° C or more and less than 110 ° C, a peroxide (c3) having an exothermic peak of 130 ° C or more and less than 140 ° C, or a peroxide having an exothermic peak of 140 ° C or more and less than 170 ° C. Peroxyketal (c1) 0.09-0.11%, peroxide (c2) 0
The thermosetting resin composition according to claim 1, wherein the content is in the range of 0 to 0.006%, 0 to 0.06% of peroxide (c3), and 0 to 0.06% of peroxide (c4). 3. The method according to claim 1, wherein the peroxyketal (c1) is 1,1
-T-butylperoxy-3,3,5-trimethylcyclohexane and 2,2-di (t-butylperoxy)
The claim 1 or claim 2 which is at least one of butane.
3. The thermosetting resin composition according to item 1. 4. A molding material comprising the thermosetting resin composition according to claim 1, wherein the addition of a resin having a glass transition temperature of 25 ° C. or less improves the impact resistance. A molding material characterized by being made.