JPH11166021A - (meth)acrylic premix, (meth)acrylic smc or bmc, and production of (meth)acrylic artificial marble - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a (meth)acrylic premix excellent in dimensional stability and hot water resistance and further excellent in productivity and appearance, and further to provide a (meth)acrylic SMC or BMC, excellent in molding processability and a thickening properties, and a method for producing a (meth) acrylic artificial marble. SOLUTION: This premix comprises (A) 100 pts.wt. of a resin composition containing (a) a (meth)acrylate having an ester group with a tricyclo ring, or monomer mixture containing the same, and (b) polymethyl methacrylate or a (meth)acrylic copolymer, (B) 1-500 pts.wt. of an inorganic filler, and (C) 0.01-20 pts.wt. of a hardener containing a compound having a >=75 deg.C 10 hr half-life temperature. The SMC and BMC comprises the premix and a thickener. The method for producing a (meth)acrylic artificial marble comprises heating, pressurizing and hardening the SMC or BMC within the range of 100-150 deg.C. The production method of the (meth)acrylic artificial marble having <=0.9% linear shrinkage comprises heating, pressurizing and hardening the SMC or BMC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is excellent in dimensional stability, hot water resistance, productivity and appearance.
A (meth) acrylic premix useful as a raw material of an acrylic artificial marble, and a (meth) acrylic SMC or BMC particularly useful as a raw material of a (meth) acrylic artificial marble having excellent moldability and viscosity. Further, the present invention relates to a method for producing a (meth) acrylic artificial marble having high productivity, good appearance and dimensional stability, and excellent hot water resistance.

[0002]

2. Description of the Related Art A (meth) acrylic artificial marble, in which an inorganic filler such as aluminum hydroxide is blended with a (meth) acrylic resin, has various outstanding functions such as excellent molded appearance, soft touch and weather resistance. It has characteristics, such as counters such as kitchen counters, vanities, waterproof pans,
Other widely used for architectural purposes.

[0003]

SUMMARY OF THE INVENTION For example, Japanese Patent Laid-Open Publication No. 2-3
Japanese Patent No. 05842 discloses tricyclo [5.2.1] as an artificial marble having excellent dimensional stability during molding and excellent hot water resistance.
[0 ^2,6 ] Artificial marble obtained by injecting a composition comprising a syrup and quartz powder containing decanyl (meth) acrylate into a molding die and then curing the same is described.

[0004] However, the composition described in JP-A-2-305842 has a problem in that productivity is low because curing requires a long time of 2 hours or more. Further, in order to shorten the curing time, for example, when these compositions are heated and cured at a high temperature of 100 ° C. or more, defects such as cracks and whitening occur in molded products, and transparency and marble are reduced. There is a problem in that the unique feeling of depth is reduced.

An object of the present invention is to provide a (meth) acrylic premix which is excellent as a raw material of a (meth) acrylic artificial marble which is excellent in dimensional stability and hot water resistance, and is also excellent in productivity and appearance, and Excellent in moldability and viscosity,
(Meth) acrylic SMC or BMC which is particularly useful as a raw material of (meth) acrylic artificial marble, and (meth) acrylic artificial marble having high productivity, good appearance and dimensional stability, and excellent hot water resistance Is to provide a method of manufacturing the same.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a (meth) acrylic resin composition which is a raw material of (meth) acrylic artificial marble has an ester group having a specific structure ( The inventors have found that the above-mentioned problems can be solved by adding (meth) acrylate and further using a specific compound as a curing agent, thereby completing the present invention.

That is, the present invention relates to a (meth) acrylate having an ester group having a tricyclo ring, or a monomer mixture (a) containing the same, and a polymethyl methacrylate or (meth) acrylic copolymer (b). ) And (meth) acrylic resin composition (A) 100 parts by weight,
It is characterized by comprising 1 to 500 parts by weight of an inorganic filler (B) and 0.01 to 20 parts by weight of a curing agent (C) containing a compound having a 10-hour half-life temperature of 75 ° C. or more (meta). It relates to acrylic premix,
The present invention relates to a (meth) acrylic SMC or BMC comprising the acrylic premix and a thickener, wherein the (meth) acrylic SMC or BM
The present invention relates to a method for producing (meth) acrylic artificial marble, wherein C is heated and pressurized in the range of 100 to 150 ° C.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The (meth) acrylic premix of the present invention comprises (meth) acrylate having an ester group having a tricyclo ring, or a monomer mixture (a) containing the same, and polymethyl methacrylate or A (meth) acrylic resin composition (A) containing a (meth) acrylic copolymer (b), an inorganic filler (B), and a compound having a 10-hour half-life temperature of 75 ° C. or higher. It is composed of a curing agent (C).

A (meth) acrylate having an ester group having a tricyclo ring, or a (meth) acrylic monomer containing the same, which is used as the component (a) constituting the (meth) acrylic resin composition (A) The body mixture is a component for imparting excellent dimensional stability and hot water resistance to the (meth) acrylic premix of the present invention, and for imparting excellent moldability and appearance.

As the (meth) acrylate having an ester group having a tricyclo ring used as the component (a), for example, adamantyl (meth) acrylate, tricyclo [ ^5.2.1.02,6 ] decanyl ( (Meth) acrylate and the like, but are not limited thereto. These may be used alone or in combination of two or more, if necessary. However, from the viewpoint of cost, tricyclo [ ^5.2.1.02,6 ] decanyl is used. (Meth) acrylates are preferred.

The (meth) acrylate having an ester group having a tricyclo ring is preferably used in an amount of 5 to 90% by weight in the (meth) acrylic resin composition (A) of the present invention. This is because when the amount of the (meth) acrylate having an ester group having a tricyclo ring is used in an amount of 5% by weight or more, the linear shrinkage at the time of curing is reduced, and the gloss unevenness of the obtained molded article is reduced. This is because the hot water resistance of the resulting molded article is improved. Further, when the content is 90% by weight or less, the mechanical strength of the obtained molded product is improved. More preferably, 10 to 85% by weight,
More preferably, it is in the range of 15 to 80% by weight.

Other monomers used as component (a) include, for example, (meth) acrylic acid esters having 1 to 20 carbon atom-containing alkyl groups, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like. ) Acrylate, glycidyl (meth) acrylate, hydroxyalkyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, trifluoroethyl (meth) acrylate, (meth) acrylic acid, metal (meth) acrylate Monofunctional monomers such as salts, fumaric acid, fumaric acid ester, maleic acid, maleic acid ester, aromatic vinyl, vinyl acetate, (meth) acrylamide, (meth) acrylonitrile, vinyl chloride, and maleic anhydride No. They are,
If necessary, they can be used alone or in combination of two or more kinds. However, a (meth) acrylic monofunctional monomer is preferable since the obtained molded article tends to have a good appearance.

Above all, the use of methyl methacrylate is particularly preferable because the resulting molded article can be given a depth peculiar to marble and tends to have a good appearance. In this case, the content of methyl methacrylate is
Although not particularly limited, it is preferable that the (meth) acrylic resin composition (A) be contained in an amount of 50% by weight or less. This is because when the content is within this range, the resulting molded article tends to have reduced gloss unevenness. It is more preferably in a range of 40% by weight or less, and particularly preferably in a range of 35% by weight or less.

Furthermore, when the acrylic resin composition of the present invention contains a polyfunctional monomer as the component (a),
Excellent strength, solvent resistance, heat resistance, dimensional stability and the like can be imparted to the obtained molded article.

Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,4-butylene glycol di ( (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, dimethylolethanedi (meth) acrylate, 1,1-dimethylolpropanedi (meth) acrylate, 2,2-dimethylolpropanedi (meth) acrylate , Trimethylolethanetri (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, neopentylglycoldi (meth)
Acrylates and polyfunctional esters of (meth) acrylic acid with polyhydric alcohols such as polyethylene glycol, polypropylene glycol, pentaerythritol and dipentaerythritol, and polyfunctional monomers such as divinylbenzene, triaryl isocyanurate and aryl methacrylate The body can be mentioned. These can be used alone or in combination of two or more as necessary.

In particular, by using neopentyl glycol dimethacrylate and / or 1,3-butylene glycol dimethacrylate as the polyfunctional monomer, the resulting molded article is imparted with excellent metallic luster and hot water resistance. Their use is particularly preferred because of their tendency.
In this case, if necessary, another polyfunctional monomer may be used in combination.

The content of these polyfunctional monomers is not particularly limited, but in order to obtain the above effects effectively, the content of the poly (meth) acrylic resin in the (meth) acrylic resin composition (A) is in the range of 1 to 50% by weight. It is preferable to contain them. This is because the gloss, strength, dimensional stability, heat resistance, and hot water resistance of the obtained molded article are improved by setting the content of the polyfunctional monomer to 1% by weight or more. Further, when the content is 50% by weight or less, the moldability of the (meth) acrylic premix of the present invention is improved. It is more preferably in the range of 3 to 40% by weight, and particularly preferably 5 to 40% by weight.
-30% by weight.

Although the content of the component (a) is not particularly limited, the workability of the (meth) acrylic premix of the present invention, and the (meth) acrylic premix of the (meth) acrylic Taking into account physical properties such as mechanical strength when used as a raw material for artificial marble,
It is preferable that the acrylic resin composition (A) is contained in the range of 10 to 90% by weight. This is because when the content of the component (a) is 10% by weight or more, the fluidity of the (meth) acrylic premix of the present invention is improved, and thus the workability is excellent. Further, by setting the content to 90% by weight or less, the linear shrinkage rate during curing of the obtained molded article can be reduced. It is more preferably in the range of 15 to 85% by weight, particularly preferably in the range of 20 to 80% by weight.

The component (b) constituting the acrylic resin composition (A) of the present invention is polymethyl methacrylate or (meth) acrylic copolymer.

Although the content of the component (b) is not particularly limited, the workability of the (meth) acrylic premix of the present invention and the (meth) acrylic premix of the (meth) acrylic premix Taking into account physical properties such as mechanical strength when used as a raw material of artificial marble,
A range of weight% is preferred. This is because by setting the content of the component (b) to 10% by weight or more, it is possible to reduce the linear shrinkage rate during curing of the obtained molded article. Further, when the content is 90% by weight or less, the flowability of the (meth) acrylic premix of the present invention is improved, and thus the workability is excellent. More preferably 15 to 85% by weight, even more preferably 20 to 85% by weight.
It is in the range of 80% by weight.

The component (b) may be a cross-linked polymer or a non-cross-linked polymer, and can be appropriately selected as necessary. However, the component (b) should be considered in consideration of the fluidity of the obtained resin composition and the mechanical strength of the molding material. When added, its weight average molecular weight is 15,0
It is preferably in the range of 00 to 2,000,000. By setting the weight average molecular weight to 15,000 or more, the mechanical strength of the obtained molded article is increased, and by setting the weight average molecular weight to 2,000,000 or less, the (meth) acrylic premix of the present invention is obtained. The reason for this is that the fluidity of the powder becomes good and the workability is excellent. More preferably, it is in the range of 25,000 to 1,000,000, and the most preferred range is 30,000 to 600,000.
00 range.

As the constituent components used in the (meth) acrylic polymer of the component (b), for example, the above-mentioned monofunctional monomers can be applied as they are. The constituent components can be used in combination of two or more kinds, and the above-mentioned polyfunctional monomers can be copolymerized if necessary. The component (b) can be produced by a known polymerization method such as a solution polymerization method, a bulk polymerization method, an emulsion polymerization method, and a suspension polymerization method.

In the present invention, the (meth) acrylic resin composition (A) may be one obtained by dissolving the component (b) in the component (a), or (a) by partially polymerizing the component (a). Component (b) which is a polymer of component (b) may be formed in the component, or component (a) may be added to the partially polymerized component, or component (b) may be further added to the partially polymerized component. May be added.

The inorganic filler (B) constituting the (meth) acrylic premix of the present invention is not particularly limited. Examples thereof include aluminum hydroxide, silica, fused silica, calcium carbonate, barium sulfate, and titanium oxide. , Calcium phosphate, talc, mica, clay, glass powder and the like. In particular, when the (meth) acrylic premix of the present invention is used as a molding material for artificial marble, the inorganic filler (B) is preferably aluminum hydroxide, silica, fused silica, calcium carbonate, or glass powder. .

The content of the component (B) is from 1 to 500 based on 100 parts by weight of the (meth) acrylic resin composition (A).
It is within the range of parts by weight. This is because by setting the content to 1 part by weight or more, the heat resistance of the obtained molded product becomes good and the linear shrinkage ratio becomes low. Also, by setting the content to 500 parts by weight or less, a molded article has a marble-like deep and good texture. The lower limit of the content of the component (B) is more preferably 50 parts by weight or more, and particularly preferably 100 parts by weight or more. Further, the upper limit of the content of the component (B) is more preferably 350 parts by weight or less, and particularly preferably 250 parts by weight or less.

The curing agent (C) constituting the (meth) acrylic premix of the present invention has a 10-hour half-life temperature of 75.
Contains compounds that are at or above ° C. When such a compound is used as a curing agent, the productivity and appearance of the obtained artificial marble are improved, and the storage stability of the (meth) acrylic premix is improved.

Examples of the compound having a 10-hour half-life temperature of 75 ° C. or more include t-butyl peroxyisobutyrate (trade name: Perbutyl IB, manufactured by NOF Corporation)
0-hour half-life temperature = 77 ° C.), di-t-butylperoxy-2-methylcyclohexane (trade name: Perhexa MC, manufactured by NOF Corporation, 10-hour half-life temperature = 83 ° C.),
1,1-bis (t-amylperoxy) 3,3,5-trimethylcyclohexane (trade name KD-2, manufactured by Kayaku Akzo Co., Ltd., 10-hour half-life temperature = 86 ° C.), 1,1,
3,3-tetramethylbutylperoxy-3,3,5-
Trimethylhexanoate (manufactured by Kayaku Akzo Co., Ltd., trade name KD-78, 10-hour half-life temperature = 86 ° C.), 1,1
-Bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane (manufactured by NOF Corporation, trade name: PerhexaTMH, 10-hour half-life temperature = 87 ° C.), 1,1-
Bis (t-hexylperoxy) cyclohexane (manufactured by NOF CORPORATION, trade name: Perhexa HC, 10-hour half-life temperature = 87 ° C.), 1,1-bis (t-butylperoxy) trimethylcyclohexane (NOF Co., Ltd., trade name Perhexa 3M, 10-hour half-life temperature = 90 ° C.),
1,1-bis (t-butylperoxy) cyclohexane (trade name Perhexa C, manufactured by NOF Corporation, 10 hour half-life temperature = 91 ° C.), 2,2-bis (4,4-di-t-)
Butyl peroxycyclohexyl) propane (manufactured by NOF Corporation, trade name: Pertetra A, 10-hour half-life temperature =
95 ° C.), t-amyl peroxy-3,3,5-trimethylhexanoate (manufactured by Kayaku Akzo Co., Ltd., trade name Kayaester AN, 10-hour half-life temperature = 95 ° C.), 1,1
-Bis (t-butylperoxy) cyclododecane (manufactured by NOF Corporation, trade name: Perhexa CD, 10-hour half-life temperature = 95 ° C), t-hexylperoxyisopropyl carbonate (manufactured by NOF Corporation, product Name perhexyl I, 10-hour half-life temperature = 95 ° C.), diethylene glycol-bis (t-butylperoxycarbonate) (manufactured by Kayaku Akzo Co., Ltd., trade name Kayalen O-50, 10-hour half-life temperature = 97 ° C.) , 1,6-bis (t-butylperoxycarbonyloxy) hexane (Kakuyaku Akzo Co., Ltd.)
Product name, Kayaren 6-70, 10 hour half-life temperature = 9
7 ° C.), t-butyl peroxylaurate (trade name: Perbutyl L, manufactured by NOF Corporation, 10 hour half-life temperature =
98 ° C.), t-butyl peroxy-2-ethylhexyl carbonate (trade name: Perbutyl E, manufactured by NOF Corporation, 10-hour half-life temperature = 99 ° C.), t-butylperoxyisopropyl carbonate (NOF Corporation) Manufactured by Perbutyl I, 10 hour half-life temperature = 99 ° C.), t
-Hexyl peroxybenzoate (Nippon Yushi Co., Ltd.)
Perhexyl Z, trade name, 10 hour half-life temperature = 99
C), t-amyl peroxybenzoate (trade name KD-1, manufactured by Kayaku Akzo Co., Ltd., 10-hour half-life temperature = 10)
0 ° C), 2,5-dimethyl-2,5-di (benzoylperoxy) hexane (trade name: Perhexa 25Z, manufactured by NOF Corporation, 10-hour half-life temperature = 100 ° C), t-butylperoxy- 3,3,5-trimethylhexanoate (trade name: Trigonox 42, manufactured by Kayaku Akzo Co., Ltd.)
10-hour half-life temperature = 100 ° C.), t-butyl peroxyacetate (manufactured by NOF CORPORATION, trade name: Perbutyl A)
−50, 10-hour half-life temperature = 102 ° C.), t-butylperoxybenzoate (trade name: Perbutyl Z, manufactured by NOF Corporation, 10-hour half-life temperature = 104 ° C.), 2,2
-Bis (t-butylperoxy) butane (trade name: Perhexa 22, manufactured by NOF Corporation, 10-hour half-life temperature = 103 ° C), n-butyl-4,4-bis (t-butylperoxy) valerate (Manufactured by NOF Corporation, trade name Perhexa V, 10-hour half-life temperature = 105 ° C), dicumyl peroxide (manufactured by NOF Corporation, trade name Parkmill D, 10-hour half-life temperature = 116 ° C), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (trade name: Perhexa 25B, manufactured by NOF CORPORATION, 10-hour half-life temperature = 118 ° C.), t-butylcumyl peroxide (Japan Made by Yushi Co., Ltd., trade name Perbutyl C, 10
Time half-life temperature = 120 ° C.), 1,3-bis (t-butylperoxyisopropyl) benzene (Perkadox 14, manufactured by Kayaku Akzo Co., Ltd., 10-hour half-life temperature = 121 ° C.), dibutyl par Oxide (manufactured by NOF Corporation, trade name: Perbutyl D, 10-hour half-life temperature =
124 ° C.) and the like; 2,2-azobis (2,
4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd.)
Manufactured, trade name V-65, 10 hour half-life temperature = 51 ° C),
2,2′-azobisisobutyronitrile (trade name: V-60, manufactured by Wako Pure Chemical Industries, Ltd., 10-hour half-life temperature = 65)
C), 1,1'-azobis (cyclohexane-1-carbonitrile) (trade name: V-4, manufactured by Wako Pure Chemical Industries, Ltd.)
(0, 10-hour half-life temperature = 88 ° C.). These can be used alone or in combination of two or more.

As the component (C), if necessary, a compound having a 10-hour half-life temperature of less than 75 ° C. can be used in combination. This makes it possible to reduce the linear shrinkage rate during curing without impairing the transparency of the obtained molded article. In this case, 75 ° C or higher compound and 75 ° C
The ratio when the compounds less than less than 75 ° C./compounds below 75 ° C. = 99.99 / 0.01 to 7
The range of 5/25 is preferable, and 99.9 / 0.1 to 90 /
A range of 10 is more preferred.

Compounds having a 10-hour half-life temperature of less than 75 ° C. include, for example, bis (4-t-butylcyclohexyl) peroxydicarbonate (Kakuyaku Akzo Co., Ltd.)
Made, trade name Parkadox 16, 10 hour half-life temperature =
44 ° C.), t-butylperoxy-2-ethylhexanoate (trade name: Perbutyl O, 10%, manufactured by NOF Corporation)
Time half-life temperature = 72 ° C.), benzoyl peroxide (manufactured by Kayaku Akzo Co., Ltd., trade name: Kadox B-CH5)
0, 10-hour half-life temperature = 72 ° C.).

The content of the component (C) is 0.01 to 100 parts by weight of the (meth) acrylic resin composition (A).
It is in the range of 20 parts by weight. This means that this content is reduced to 0,1.
When the amount is at least 01 parts by weight, the curability of the (meth) acrylic premix will be sufficient, and when the amount is at most 20 parts by weight, the storage stability of the (meth) acrylic premix will be good. . The lower limit of the content of the component (C) is more preferably 0.1 part by weight or more, and the upper limit is more preferably 10 parts by weight.

Further, by mixing and molding the (meth) acrylic premix of the present invention with resin particles containing an inorganic filler, a granite-like artificial marble having a stone pattern can be obtained.

The blending amount of the resin particles containing an inorganic filler is not particularly limited, but the (meth) acrylic premix 100
It is preferably in the range of 0.1 to 200 parts by weight based on parts by weight. This is because, by setting the blending amount of the inorganic filler-containing resin particles to 0.1 parts by weight or more, a stone pattern with good designability is obtained, and by setting the blending amount to 200 parts by weight or less, the (meth) acrylic This is because the kneadability during the production of the mix is improved. More preferably 1-1
It is in the range of 00 parts by weight.

The resin constituting the inorganic filler-containing resin particles may be any resin that does not dissolve in methyl methacrylate, and examples thereof include a crosslinked (meth) acrylic resin, a crosslinked polyester resin, and a crosslinked styrene resin.
A crosslinked (meth) acrylic resin is preferred because a molded article having a high affinity with the acrylic resin composition (A) of the present invention and having a beautiful appearance can be obtained. The crosslinked (meth) acrylic resin may contain a non-crosslinked (meth) acrylic polymer containing polymethyl methacrylate or methyl methacrylate as a main component.

The inorganic filler constituting the inorganic filler-containing resin particles is preferably used in a range of 1 to 500 parts by weight based on 100 parts by weight of the resin. This is because by using the inorganic filler in an amount of 1 part by weight or more, the texture and heat resistance of the obtained molded article are improved, and by using the inorganic filler in an amount of 500 parts by weight or less. This is because it is possible to give a molded article a marble-like deep and good texture.

As the inorganic filler, aluminum hydroxide, silica, fused silica, calcium carbonate, barium sulfate, titanium oxide, calcium phosphate, calcium carbonate,
Inorganic fillers such as talc, clay and glass powder can be used as needed. In particular, when producing granite-like artificial marble, as an inorganic filler,
Aluminum hydroxide, silica, fused silica, and glass powder are preferred.

The method for producing the inorganic filler-containing resin particles is not particularly limited. For example, a resin molded product containing an inorganic filler obtained by polymerization and curing by a hot press method, a casting method, or the like is pulverized and classified by sieving. Method. For example, it is preferable to use inorganic filler-containing resin particles obtained by grinding and classifying (meth) acrylic artificial marble.

In the present invention, one kind, or two or more kinds of resin particles containing an inorganic filler having different colors and particle sizes can be used. The particle size of the inorganic filler-containing resin particles is not particularly limited as long as it is equal to or less than the thickness of the molded product.

The (meth) acrylic premix of the present invention may be heat-cured or redox-cured by a casting method as it is, or after adding a thickener to form a (meth) acrylic SMC or BMC. Heat and pressure curing may be used. Above all, a method in which a (meth) acrylic SMC or BMC is formed and then heated and pressurized is preferable from the viewpoint of productivity.

There is no particular limitation on the thickening agent used when the (meth) acrylic SMC or BMC is used, and for example, magnesium oxide powder or polymer powder can be used. In particular, a polymer powder is preferable because the molded article tends to have excellent water resistance.

The polymer powder that can be used as a thickener is not particularly limited and can be appropriately selected as needed. For example, it is possible to use the above-mentioned resin particles containing an inorganic filler as a thickener. However, the bulk density is 0.1 to 0.
7 g / ml and an oil absorption of linseed oil of 6
It is preferable to use a non-crosslinked polymer powder having a range of 0 to 200 ml / 100 g and a swelling degree of 16 times or more with respect to methyl methacrylate. When such a specific polymer powder is used as a thickener, a (meth) acrylic SMC or BMC excellent in handling properties and productivity can be obtained,
In addition, molded articles having good appearance tend to be obtained.

This means that the bulk density of the polymer powder was 0.1 g /
When the amount is set to not less than 0.1 ml, the polymer powder is less likely to be scattered, the yield during the production thereof is improved, and powdering when adding and mixing the polymer powder to the (meth) acrylic premix is reduced. It is because the property becomes good, and by making it 0.7 g / ml or less,
This is because a sufficient thickening effect can be obtained by using a small amount of the polymer powder, and the thickening can be completed in a short time, so that the productivity is improved and the cost is advantageous. Preferably, it is in the range of 0.15 to 0.65 g / ml, and more preferably in the range of 0.2 to 0.6 g / ml.

When the amount of oil absorbed by the polymer powder in linseed oil is 60 ml / 100 g or more, a sufficient thickening effect can be obtained by using a small amount of the polymer powder, and the thickening can be performed in a short time. , The productivity is improved and the cost is also advantageous.
When the content is 100 g or less, the dispersibility of the polymer powder in the (meth) acrylic premix becomes good, and the kneading property when producing the (meth) acrylic SMC or BMC becomes good. . Preferably,
It is in the range of 70 to 180 ml / 100 g, and more preferably in the range of 80 to 140 ml / 100 g.

Further, by making the degree of swelling of the polymer powder to methyl methacrylate 16 times or more,
This is because the effect of thickening the (meth) acrylic premix becomes sufficient. More preferably, it is 20 times or more.

The polymer powder may be a non-crosslinked polymer powder or a crosslinked polymer powder, but is preferably a non-crosslinked polymer powder. This is because the polymer powder is a non-crosslinked polymer powder, whereby a sufficient thickening effect can be obtained in a short time, and a (meth) acrylic SMC or BMC containing this polymer powder can be produced into granite-like artificial marble. This is because, when used, the sharpness of the grain pattern is improved, and the grain pattern tends to be non-uniform. This tendency is considered to be due to the fact that, after the non-crosslinked polymer powder swells in the (meth) acrylic premix, part or all of it immediately dissolves even at room temperature.

In the present invention, the term "non-crosslinked polymer powder" means a polymer powder having at least a surface layer composed of a non-crosslinked polymer.

The weight average molecular weight of the polymer powder used in the present invention is not particularly limited, but may be 100,000 to 2
It is preferably in the range of one million.

When the weight average molecular weight is within this range, a sufficient thickening effect can be obtained in a short time, and the (meth) acrylic SMC or BM containing this polymer powder can be obtained.
This is because when C is used for the production of granite-like artificial marble, the sharpness of the grain pattern is improved, and the unevenness of the grain pattern is eliminated. It is more preferably in the range of 300,000 to 2,000,000, and particularly preferably in the range of 400,000 to 1,000,000.

The amount of the polymer powder used in the present invention is not particularly limited, but the amount of the polymer powder is 0.1 to 100 parts by weight based on 100 parts by weight of the acrylic resin composition (A) of the present invention.
It is preferably in the range of 100 parts by weight. This is because when the amount of the polymer powder used is 0.1 part by weight or more, a high thickening effect is exhibited, and when the amount is 100 parts by weight or less, the dispersibility of the polymer powder becomes good, and the cost becomes advantageous. It is. A more preferred amount of the polymer powder is in the range of 1 to 80 parts by weight.

The specific surface area of the polymer powder used in the present invention is not particularly limited.
It is preferably in the range of m ² / g.

This means that the specific surface area of the polymer powder is 1 m ² /
g or more, a sufficient thickening effect is obtained with the use of a small amount of the polymer powder, and the thickening becomes possible in a short time, thereby improving the productivity and further including the polymer powder. When (meth) acrylic SMC or BMC is used for the production of granite artificial marble, the sharpness of the grain pattern is improved, the unevenness of the grain pattern is eliminated, and 100 m ² /
When the amount is not more than g, the dispersibility of the polymer powder in the (meth) acrylic premix becomes good, and the kneading property when producing the (meth) acrylic SMC or BMC becomes good. . More preferably 3 to
100 m ² / g, more preferably 5 to 1
00 m ² / g.

The average particle size of the polymer powder is not particularly limited, but is preferably in the range of 1 to 250 μm. This is because, by setting the average particle diameter to 1 μm or more, the powdering of the powder is reduced, and the handleability of the polymer powder becomes good. By setting the average particle diameter to 250 μm or less, the appearance of the obtained molding material, particularly gloss This is because the surface smoothness becomes good. More preferably, 5-1
50 μm, more preferably 10 to 70 μm.
It is in the range of μm.

The polymer powder used in the present invention is preferably a secondary aggregate in which primary particles are aggregated. This is because when the polymer powder has the shape of a secondary aggregate, the absorption rate of the component (a) of the present invention is high, and the viscosity is extremely good.

In this case, the average particle diameter of the primary particles of the polymer powder is preferably in the range of 0.03 to 1 μm. This means that the average particle size of the primary particles is set to 0.
By setting the particle size to 03 μm or more, the yield during the production of the polymer powder that is a secondary aggregate is improved, and by setting the particle size to 1 μm or less, a sufficient thickening effect can be obtained by using a small amount of the polymer powder. Is possible in a short time, so that the productivity is improved.
This is because when acrylic SMC or BMC is used for the production of granite-like artificial marble, the sharpness of the grain pattern is improved, and the unevenness of the grain pattern is eliminated. More preferably,
It is in the range of 0.07 to 0.7 μm.

As the polymer constituting the polymer powder, various polymers can be appropriately selected and used as needed, and are not particularly limited, but the appearance of the obtained (meth) acrylic artificial marble and the like are not particularly limited. In consideration of the above point, the (meth) acrylic polymer is preferable.

The constituents of the polymer powder include, for example,
Alkyl (meth) having an alkyl group having 1 to 20 carbon atoms
Acrylate, cyclohexyl (meth) acrylate,
Glycidyl (meth) acrylate, hydroxyalkyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, trifluoroethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylate metal salt, fumaric Examples include acid, fumaric acid ester, maleic acid, maleic acid ester, aromatic vinyl, vinyl acetate, (meth) acrylamide, (meth) acrylonitrile, vinyl chloride, maleic anhydride and the like. These may be polymerized alone if necessary, or may be copolymerized in combination of two or more,
(Meth) acrylic monomers are preferred in consideration of the affinity with the monomer components constituting the (meth) acrylic premix.

Further, the polymer powder used in the present invention is:
Polymer powder having a so-called core / shell structure composed of a core phase and a shell phase having different chemical compositions, structures, molecular weights, and the like of the polymers forming them can also be used. In this case, the core phase may be a non-crosslinked polymer or a crosslinkable polymer, but the shell phase is preferably a noncrosslinked polymer.

The constituent components of the core phase and the shell phase of the polymer powder include, for example, an alkyl (meth) acrylate having an alkyl group having 1 to 20 carbon atoms, cyclohexyl (meth) acrylate, glycidyl (meth) acrylate, hydroxyalkyl (Meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, trifluoroethyl (meth) acrylate, (meth) acrylic acid, metal (meth) acrylate, fumaric acid, fumaric acid ester, maleic acid , Maleic ester, aromatic vinyl, vinyl acetate, (meth) acrylamide, (meth) acrylonitrile, vinyl chloride, maleic anhydride and the like. These may be polymerized singly or may be used in combination of two or more, if necessary, but have an affinity for the monomer component constituting the (meth) acrylic premix. From the viewpoint of heightening, it is preferable that the shell phase uses methyl methacrylate as a main component.

When the core phase is crosslinked, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butylene glycol di ( (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, dimethylolethanedi (meth) acrylate, 1,1-dimethylolpropanedi (meth) acrylate, 2,2-dimethylolpropanedi (meth) acrylate , Trimethylolethanetri (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, neopentylglycoldi (meth)
Acrylates and polyfunctional esters of (meth) acrylic acid with polyhydric alcohols such as polyethylene glycol, polypropylene glycol, pentaerythritol and dipentaerythritol, and polyfunctional monomers such as divinylbenzene, triaryl isocyanurate and aryl methacrylate The body can be used as a constituent component, and these can be used alone or in combination of two or more.

Although the polymer powder of the present invention may contain an inorganic filler, it is preferable that the polymer powder does not contain an inorganic filler in order to further increase the thickening effect.

The method for producing the polymer powder is not particularly limited, and examples thereof include bulk polymerization, solution polymerization, suspension polymerization,
It can be obtained by known methods such as emulsion polymerization and dispersion polymerization. Among them, a method of obtaining a polymer powder by subjecting an emulsion obtained by emulsion polymerization to a treatment such as spray drying, freeze drying, or salt / acid precipitation is preferable because the production efficiency is good.

The acrylic premix of the present invention may further include a reinforcing material such as glass fiber and carbon fiber, if necessary.
Various additives such as a colorant, a low-shrinkage agent, a curing agent, and an internal release agent can be added.

The method of mixing the components for obtaining the (meth) acrylic premix of the present invention is not particularly limited as long as it is a method capable of efficiently mixing a substance having a high viscosity. For example, a kneader, a mixer, a roll, an extruder, or the like can be used.

The (meth) acrylic premix of the present invention is thickened to form a (meth) acrylic SMC or BM
In obtaining C, the above-described various mixing devices can be used. In particular, when a non-crosslinked polymer having the specific bulk density, oil absorption and swelling degree is used as a thickener, the acrylic SMC or BMC of the present invention thickens and matures to a non-sticky level in a short time. Is unnecessary, the various constituent components are uniformly mixed and simultaneously thickened and extruded, and are molded into a predetermined shape to form a (meth) acrylic SM.
C or BMC can also be manufactured continuously.

In the case where the (meth) acrylic premix of the present invention is made into acrylic SMC or BMC and then cured under heating and pressure to produce artificial marble, compression molding, transfer molding, injection molding, extrusion molding, It can be manufactured by a method such as a molding method.

In this case, the heating temperature is not particularly limited, but is preferably in the range of 100 to 150 ° C. this is,
By setting the heating temperature to 100 ° C. or higher, it is possible to perform heating with steam which is advantageous in cost, and it is possible to shorten the curing time and to increase the productivity. This is because the linear shrinkage of the obtained molded article tends to be low. More preferably 105 to 145 ° C, particularly preferably 110 to 1
It is in the range of 40 ° C. Further, the upper mold and the lower mold may be heated with a temperature difference within the above temperature range.

The pressure is preferably in the range of 1 to 20 MPa. This is because when the pressurizing pressure is 1 MPa or more, the filling property of the (meth) acrylic SMC or BMC into the mold tends to be good. This is because a molded appearance tends to be obtained. More preferably, 2 to 15
MPa range.

The molding time may be appropriately selected depending on the thickness of the molded article.

The (meth) acrylic BMC or S of the present invention
The artificial marble obtained by curing the MC under heat and pressure has excellent molded appearance and hot water resistance, and can have a linear shrinkage of 0.9% or less.

[0069]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples. Parts and% in the examples are on a weight basis except for the value of linear shrinkage.

Physical properties of polymer powder Average particle diameter: Measured using a laser diffraction / scattering type particle size distribution analyzer (LA-910, manufactured by HORIBA, Ltd.).

Bulk density: JIS R 6126- 1970
It measured based on.

Oil absorption: JIS K 5101-1991
The end point was taken immediately before the putty-like mass suddenly softened with the last drop of linseed oil.

Specific surface area: Measured by a nitrogen adsorption method using a surface area meter SA-6201 (manufactured by Horiba, Ltd.).

Weight average molecular weight: measured value by GPC method (in terms of polystyrene) Swelling degree: The polymer powder was charged into a 100-ml graduated cylinder, patted several times and packed in 5 ml, and then cooled to 10 ° C. or lower methyl methacrylate Is added so that the total amount becomes 100 ml, and the mixture is rapidly stirred so that the whole becomes uniform. Thereafter, the graduated cylinder was kept in a thermostat at 25 ° C. for 1 hour, and the volume of the polymer powder layer after swelling was determined and indicated by the ratio to the volume before swelling (5 ml).

Measurement of Linear Shrinkage of Molded Product The actual size (Lmm) of the molded product was measured, and the mold size (L0m
m) was determined by the following equation.

Linear shrinkage (%) = {(L ₀ −L) / L ₀ } × 100 (%) Physical properties of molded product Hot water resistance: A molded plate is immersed in hot water of 98 ° C. for 120 hours, The color change (whiteness, color difference, yellowing degree) was compared with the plate before immersion.

(1) Production Example of Polymer Powder (P-1) In a reactor equipped with a cooling pipe, a thermometer, a stirrer, a dropping apparatus, and a nitrogen introduction pipe, 925 parts of pure water, sodium alkyldiphenyl ether disulfonate were added. 5 parts (manufactured by Kao Corporation, trade name: Perex SS-H) and 1 part of potassium persulfate were charged and heated to 70 ° C. while stirring under a nitrogen atmosphere. A mixture consisting of 500 parts of methyl methacrylate and 5 parts of sodium dialkylsulfosuccinate (trade name: Perex OT-P, manufactured by Kao Corporation) was added dropwise over 3 hours, and the mixture was maintained for 1 hour, and further heated to 80 ° C. The emulsion polymerization was terminated by heating and holding for 1 hour to obtain an emulsion having a polymer primary particle diameter of 0.08 μm.

The obtained emulsion was subjected to an inlet / outlet temperature = 1 using an L-8 type spray dryer manufactured by Okawara Kakoki Co., Ltd.
A spray drying treatment at 50 ° C / 90 ° C was performed to obtain a non-crosslinked polymer powder (P-1) having an average particle diameter of the secondary aggregate particles of 30 µm. The bulk density of the obtained (P-1) was 0.40 g / ml, and the oil absorption of linseed oil was 100 ml / 100.
g, and the degree of swelling with respect to methyl methacrylate is 20.
The specific surface area was 51 m ² / g, and the weight average molecular weight was 600,000.

(2) Production Example of Polymer Powder (P-2) 925 parts of pure water, sodium alkyldiphenyl ether disulfonate were placed in a reactor equipped with a cooling pipe, a thermometer, a stirrer, a dropping device, and a nitrogen inlet tube. 5 parts (manufactured by Kao Corporation, trade name: Perex SS-H) and 1 part of potassium persulfate were charged and heated to 70 ° C. while stirring under a nitrogen atmosphere. To this, 149.85 parts of methyl methacrylate, 1,3-
A mixture consisting of 0.15 parts of butylene glycol dimethacrylate and 5 parts of sodium dialkyl sulfosuccinate (trade name: Perex OT-P, manufactured by Kao Corporation) is mixed with 1.5 parts.
After dripping over time, holding for 1 hour, and then dripping 350 parts of methyl methacrylate over 3.5 hours,
After holding for 1 hour, further raising the temperature to 80 ° C., and holding for 1 hour to complete the emulsion polymerization, the primary particle size of the polymer was 0.10 μm.
m of emulsion was obtained.

The obtained emulsion was subjected to an inlet / outlet temperature = 1 using an L-8 type spray dryer manufactured by Okawara Kakoki Co., Ltd.
Spray drying at 50 ° C./90° C. to obtain a polymer powder having a core / shell structure in which the average particle diameter of the secondary aggregate particles is 20 μm, the core phase is a crosslinked polymer, and the shell phase is a non-crosslinked polymer ( P-2) was obtained. The bulk density of the obtained (P-2) is 0.38 g / ml, and the oil absorption of linseed oil is
100 ml / 100 g, the degree of swelling with respect to methyl methacrylate is 20 times or more, and the specific surface area is 51 m ^2.
/ G, and the weight average molecular weight of the shell phase was 600,000.

(3) Production Example of Polymer Powder (P-3) The charged amount of potassium persulfate was 0.25 part, and the monomers to be dropped were 497.5 parts of methyl methacrylate and 1,3-butylene glycol dimethacrylate. Emulsion polymerization was carried out in the same manner as in the production example of the polymer powder (P-1) except that the mixture was 2.5 parts and 5 parts of sodium dialkylsulfosuccinate, and the primary particle size of the polymer was 0.18 μm. I got an emulsion. The obtained emulsion was spray-dried in the same manner as in Production Example (1) to obtain a crosslinked polymer powder (P-3) having an average particle diameter of the secondary aggregate particles of 18 µm. The bulk density of the obtained (P-3) is 0.38 g / ml.
And the oil absorption of linseed oil is 95 ml / 100
g, and the degree of swelling with respect to methyl methacrylate is 20.
And the specific surface area was 24 m ² / g.

(4) Polymethyl methacrylate (B-
Production Example 1) 800 parts of pure water and polyvinyl alcohol (degree of saponification 8) were placed in a reactor equipped with a cooling pipe, a thermometer, a stirrer, and a nitrogen introduction pipe.
After dissolving 1 part of 8% and a degree of polymerization of 1000), a monomer solution in which 400 parts of methyl methacrylate, 2 parts of normal dodecyl mercaptan and 2 parts of azobisisobutyronitrile are dissolved is added, and the mixture is placed under a nitrogen atmosphere. While stirring at 400 rpm, the temperature was raised to 80 ° C. in 1 hour, and the mixture was directly heated for 2 hours. Thereafter, the temperature was raised to 90 ° C., and the mixture was heated for 2 hours.
The mixture was heated to 20 ° C., and the remaining monomers were distilled off together with water to obtain a slurry, thereby completing the suspension polymerization. After filtering and washing the obtained slurry, it was dried with a hot air dryer at 50 ° C. to obtain polymethyl methacrylate (B-1) having an average primary particle diameter of 93 μm. The bulk density of the obtained (B-1) was 0.70 g / ml, and the oil absorption of linseed oil was:
45 ml / 100 g, the swelling degree with respect to methyl methacrylate is 1.2, and the specific surface area is 0.07 m ² /
g, and the weight average molecular weight was 40,000.

(5) Production Example of Resin Particles Containing Inorganic Filler A mixture 100 consisting of 69% of methyl methacrylate, 2% of ethylene glycol dimethacrylate, and 29% of polymethyl methacrylate (B-1) obtained in Production Example (4).
In parts, 2.0 parts of t-butyl peroxybenzoate (trade name: Perbutyl Z, manufactured by NOF Corporation) as a curing agent,
After adding 0.5 part of zinc stearate and 0.25 part of a white inorganic pigment or a black inorganic pigment as an internal release agent, aluminum hydroxide (manufactured by Showa Denko KK,
200 parts of Hygilite H-310) (trade name) were added, and the polymer powder (P-1) 30 obtained in Production Example (1) was further added.
Part, and knead with a kneader for 10 minutes.
MC was obtained. Next, an acrylic BMC was filled into a 200 mm square flat mold, and the mold temperature was 130 ° C. and the pressure was 100 °.
The mixture was cured by heating and pressure under the condition of kg / cm ² for 10 minutes to obtain an acrylic artificial marble having a thickness of 10 mm. The obtained acrylic artificial marble was pulverized with a crusher to obtain white or black inorganic filler-containing resin particles having an average particle diameter of 350 μm.

Example 1 Tricyclo [5.2.1.0]
^2,6 ] decanyl methacrylate (Hitachi Chemical Industries, Ltd.)
25 parts, methyl methacrylate (manufactured by Mitsubishi Rayon Co., Ltd., trade name Acryester M) 23 parts, neopentyl glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name NK) Ester NPG) 25 parts, ethylene glycol dimethacrylate (Acryester ED, manufactured by Mitsubishi Rayon Co., Ltd.) 2
Part of the (meth) acrylic monomer (a) component,
As a component (b), 100 parts of a (meth) acrylic resin composition in which 25 parts of the polymethyl methacrylate (B-1) obtained in Production Example (1) were dissolved, and 1,1-bis (t- Butylperoxy) 3,3,5-trimethylcyclohexane (trade name: Perhexa 3 manufactured by NOF Corporation)
M, 10 hours half-life temperature = 90 ° C.), 2.0 parts of zinc stearate as an internal mold release agent, and aluminum hydroxide as an inorganic filler (Showa Denko KK)
And 195 parts of trade name (Heidilite H-310), and 25 parts of the polymer powder (P-1) obtained in the above Production Example (1) as a thickener, and kneaded with a kneader for 10 minutes. Thus, a (meth) acrylic BMC was obtained. The obtained (meth) acrylic BMC had no stickiness immediately after kneading, and had extremely good handleability.

Next, the obtained (meth) acrylic B
MC is filled into a molding die, and is heated and cured for 10 minutes under the conditions of an upper die temperature of 140 ° C., a lower die temperature of 125 ° C., and a pressure of 9.8 MPa, and has a thickness of 10 mm and a 200 mm square (meth) acrylic. An artificial marble molded product was obtained.

The surface of the obtained molded product had no gloss unevenness, was extremely high in gloss, and had an extremely good appearance.
Further, the molded article had high transparency and had a marble-like depth. The linear shrinkage of the molded product was as low as 0.80%. Also,
The color change of the molded article after immersion in hot water was extremely small, and the hot water resistance was extremely good.

Example 2 Tricyclo [5.2.1.0]
⁽⁶ )] (Meth) acrylic BMC was obtained in the same manner as in Example 1 except that decanyl methacrylate was 19% and methyl methacrylate was 29%. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 3 Tricyclo [5.2.1.0]
^[2,6 ] (Meth) acrylic BMC was obtained in the same manner as in Example 1 except that decanyl methacrylate was 15% and methyl methacrylate was 33%. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 4 Tricyclo [5.2.1.0]
^[2,6 ] Decanyl methacrylate was 9% and methyl methacrylate was 39%, and a (meth) acrylic BMC was obtained in the same manner as in Example 1. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 5 As a polymer powder (P-2)
(Meth) acrylic BMC was obtained in the same manner as in Example 1 except for using. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 6 Neopentyl glycol dimethacrylate was 15% polymethyl methacrylate (B
(Meth) acrylic BMC was obtained in the same manner as in Example 1, except that -1) was 35% and the polymer powder was (P-3). Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 7 Tricyclo [5.2.1.0]
Instead of [ ^2,6 ] decanyl methacrylate, tricyclo [ ^5.2.1.02,6 ] decanyl acrylate (Fancryl FA-513A, manufactured by Hitachi Chemical Co., Ltd.)
A (meth) acrylic BMC was obtained in the same manner as in Example 1 except for using. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Example 8 Tricyclo [5.2.1.0]
^2,6 ] decanyl methacrylate 24 parts, methyl methacrylate 24 parts, neopentyl glycol dimethacrylate 25 parts, ethylene glycol dimethacrylate 2 parts (meth) acrylic monomer (a) component, (b)
As a component, 100 parts of a (meth) acrylic resin composition in which 25 parts of the polymethyl methacrylate (B-1) obtained in Production Example (1) was dissolved, and 1,1-bis (t-
(Butylperoxy) 3,3,5-trimethylcyclohexane 2.0 parts, zinc stearate 0.1 part as an internal release agent.
After adding 5 parts, aluminum hydroxide was used as an inorganic filler (manufactured by Showa Denko KK, trade name Hygilite H-31).
0) 170 parts and a total of 70 parts of the black and white inorganic filler-containing resin particles obtained in Production Example (5) were added, and the polymer powder obtained in Production Example (1) was further used as a thickener. P-
1) 25 parts were added and kneaded with a kneader for 10 minutes. The obtained stone-grained (meth) acrylic BMC had no stickiness immediately after kneading and was extremely good in handleability.

Next, a granite-like (meth) acrylic artificial marble molded product was obtained in the same manner as in Example 1. Table 1 shows the appearance, linear shrinkage, and evaluation results of hot water resistance of the obtained molded product.

Comparative Example 1 A (meth) acrylic resin composition was obtained by mixing 48 parts of methyl methacrylate, 25 parts of neopentyl glycol dimethacrylate, 2 parts of ethylene glycol dimethacrylate, and the polymethyl methacrylate obtained in Production Example (1). (B-1) A (meth) acrylic BMC was obtained in the same manner as in Example 1, except that the mixture was composed of 25 parts. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. The obtained molded article had uneven gloss and had a poor appearance. The linear shrinkage of molded products is also 0.9
It was as large as 3%. The color change of the molded product after immersion in hot water was large.

Comparative Example 2 Tricyclo [5.2.1.0]
⁽⁶ )] A (meth) acrylic BMC was obtained in the same manner as in Example 1 except that styrene was used instead of decanyl methacrylate. Table 1 shows the results of the viscosity increase.

Next, a (meth) acrylic artificial marble was obtained in the same manner as in Example 1. The obtained molded product had severe gloss unevenness, low gloss, and very poor appearance. The linear shrinkage of the molded product was as large as 0.91%.

Comparative Example 3 Perhexa 3 was used as a curing agent.
Example 4 was repeated except that benzoyl peroxide (trade name: Kadox B-CH50, manufactured by Kayaku Akzo Co., Ltd., trade name: 10-hour half-life temperature = 72 ° C.) was used in place of M. A (meth) acrylic premix was obtained in the same manner.

This (meth) acrylic premix was filled in a molding die, and a molded product was obtained in the same manner as in Example 1. The obtained molded product was whitened, had low transparency, and did not have a deep feeling peculiar to marble.

[0107]

[Table 1]

513M: tricyclo [5.2.1.0]
^2,6] decanyl methacrylate 513A: tricyclo [5 · 2 · 1 · 0 ^2,6] decanyl acrylate MMA: methyl methacrylate NPGDMA: Neopentyl glycol dimethacrylate EDMA: ethylene glycol dimethacrylate ST: Styrene Perhexa 3M: 1, 1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane B-CH50: Benzoyl peroxide Thickening of the premix A: The viscosity increases immediately after kneading and has good tack-free handling. A mix was obtained.

B: After kneading, it took 24 hours or more to ripen at room temperature to increase the viscosity to the required viscosity.

Gloss unevenness of molded article A: There is no gloss unevenness, and the gloss is extremely high.

○: No gloss unevenness and high gloss.

Δ: There is uneven gloss and the gloss is low.

X: The gloss unevenness is severe and the gloss is extremely low.

The depth of the molded article (transparency) ：: The molded article has a high degree of transparency and has a marble-like depth.

X: The molded product was whitened, had low transparency, and did not have the depth characteristic of marble.

Hot water resistance of molded article A: Color change was extremely small.

○: The color change was small.

X: The color change was large.

[0119]

As is clear from the above embodiments,
By including a (meth) acrylate having an ester group of a specific structure as a (meth) acrylic resin composition and a specific compound as a curing agent, a linear shrinkage ratio is small, and a molded appearance without unevenness in gloss is obtained. It is possible to obtain a (meth) acrylic premix useful as a raw material for (meth) acrylic artificial marble with excellent moldability, and to add a polymer as a thickener to this (meth) acrylic premix. By containing the powder,
It is possible to obtain (meth) acrylic SMC or BMC which is suitable for high-temperature molding and has excellent moldability and is particularly useful as a raw material for (meth) acrylic artificial marble. The (meth) acrylic artificial marble has high productivity, is excellent in appearance, dimensional stability, and hot water resistance, is extremely useful particularly for bathtub use, and is industrially very useful.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08J 5/10 C08J 5/10 5/24 CEY 5/24 CEY C08K 3/00 C08K 3/00 C08L 33/00 C08L 33/00 51/00 51/00 // B29K 33:04 105: 06 (72) Inventor Yuichiro Kishimoto 4-160 Sunadabashi, Higashi-ku, Nagoya City, Aichi Prefecture Mitsubishi Rayon Co., Ltd. Product Development Laboratory

Claims (7)

[Claims] 1. A (meth) acrylate having an ester group having a tricyclo ring, or a monomer mixture (a) containing the same, and a polymethyl methacrylate or (meth) acrylic copolymer (b) (Meth) acrylic resin composition (A) 100 parts by weight, inorganic filler (B) 1
(Meth) acrylic premix comprising from 0.01 to 500 parts by weight and from 0.01 to 20 parts by weight of a curing agent (C) containing a compound having a 10-hour half-life temperature of 75 ° C. or higher. 2. The method according to claim 1, wherein the (meth) acrylate having an ester group having a tricyclo ring is tricyclo [5.2.1.0].
^2,6 ] decanyl (meth) acrylate. The (meth) acrylic premix according to claim 1, wherein 3. The (meth) acrylic premix according to claim 2, further comprising an inorganic filler-containing resin particle. 4. A (meth) acrylic SMC or BMC comprising the (meth) acrylic premix according to claim 2 and a thickener. 5. The (meth) acrylic SMC or B according to claim 4, wherein the thickener is a polymer powder.
MC. 6. The (meth) acrylic SM according to claim 4,
A method for producing a (meth) acrylic artificial marble, wherein C or BMC is cured by heating and pressurizing in the range of 100 to 150 ° C. 7. The (meth) acrylic SM according to claim 4,
A method for producing (meth) acrylic artificial marble having a linear shrinkage of 0.9% or less, wherein C or BMC is cured by heating and pressing.