JPH03250045A - Molding material for artificial marble - Google Patents

Abstract

PURPOSE:To prepare the title material giving a translucent molded article which has a glossy surface and shows a low linear shrinkage, neither warp nor strain, and an excellent heat resistance by compounding an unsatd. polyester resin, aluminum hydroxide, and an N-substd. maleimide homopolymer, each in a specified amt., with a hardener. CONSTITUTION:100 pts.wt. unsatd. polyester resin (e.g. Upica 6500, a product of Nippon Upica Co., Ltd.), 30-300 pts.wt. aluminum hydroxide, 3-50 pts.wt. N-substd. maleimide homopolymer (e.g. an N-phenylmaleimide homopolymer), and a hardener (e.g. methyl ethyl ketone peroxide) are compounded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a molding material for artificial marble.

(Conventional technology) In recent years, artificial marble has been manufactured using organic and inorganic materials as a substitute for natural marble. Typical manufacturing methods include methods based on acrylic resin and methods based on unsaturated polyester resin. This method is known.

There are three methods for molding artificial marble using unsaturated polyester resin: normal temperature and pressure casting, heat molding, and heat pressure molding, but the room temperature and pressure casting method is inferior in productivity; However, the heat molding method tends to cause cracks, and therefore a method has been used to improve low shrinkage by adding a large amount of thermoplastic resin. However, although this method reduced the occurrence of cranking, there were problems such as the molded product becoming opaque. For these problems, Japanese Patent Application Laid-Open No. 63-118361
An unsaturated polyester resin molding material containing a filler such as polystyrene with a limited average particle size has been proposed, as shown in No. 1, but there were problems such as heat resistance and lack of surface gloss.

(Problems to be Solved by the Invention) The present invention aims to obtain artificial marble that can be heat-formed, has a translucent and glossy surface, has an excellent appearance without warping or distortion, and has good heat resistance. The purpose is to provide a molding material for artificial marble that can be mass-produced.

(Means for Solving the Problems) That is, the present invention provides an unsaturated polyester resin, and 30 to 300 parts by weight per 100 parts by weight of this unsaturated polyester resin.
The present invention provides a molding material for artificial marble containing parts by weight of aluminum hydroxide, 3 to 50 parts by weight of an N-substituted maleimide homopolymer, and a hardening agent.

The unsaturated polyester resin in the present invention refers to α, β-
Obtained by condensing an unsaturated acid, optionally an aromatic dicarboxylic acid or a saturated aliphatic dicarboxylic acid, and a polyhydric alcohol at, for example, 180°C to 250°C, and mixing other monomers with the condensation reaction. It is a viscous liquid.

Examples of the α,β-unsaturated acids include maleic acid, maleic anhydride, fumaric acid, itaconic acid, and citraconic acid, and two or more of them can be used as a mixture if necessary. aromatic dicarboxylic acid used as necessary;
Or saturated aliphatic dicarboxylic acids include phthalic acid, phthalic anhydride, halogenated phthalic anhydride, isophthalic acid,
Examples include terephthalic acid, tetrahydrophthalic acid, 3,6-nindomethylenetetrahydrophthalic acid, succinic acid, azelaic acid, adipic acid, glutaric acid, pimelic acid, and cepatic acid.

Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and I.

3-butylene glycol, 1,6-hexanediol,
Examples include neopentyl glycol, hydrogenated hisphenol A, and adducts of bisphenol A with ethylene oxide and propylene oxide.

The unsaturated polyester resin is not limited to one type, and two or more types can be used in combination.

Other monomers include, for example, styrene, halogenated styrene, α-methylstyrene, vinyltoluene, divinylbenzene, diallyl phthalate, diallyl phthalate prepolymer, chlorostyrene, dichlorostyrene, bromostyrene, dipromostyrene, diallylbenzene. Phosphonates, diallylaryl phosphinic acid esters,
Acrylic esters, methacrylic esters, triallyl cyanurate, tribromophenol allyl ether, N-substituted maleimides, and the like are used. These other monomers are not limited to one type (although two or more types can also be used in combination).

In the present invention, the N-substituted maleimide compound constituting the N-substituted maleimide homopolymer can be represented by the following large amount (1).

\ It NR3(1) / (In the formula, R1 and Rt each represent a hydrogen atom, a halogen atom, or a methyl group, and R3 is a straight chain or branched alkyl group having 1 to 18 carbon atoms, or a cycloalkyl group having 3 to 12 carbon atoms. ,
represents an alkyl-substituted cycloalkyl group having 3 to 12 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an aralkyl group).

As the N-substituted maleimide compound, for example, N-
Methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-
n-butylmaleimide, N5ec-butylmaleimide,
N-n-hexylmaleimide, N-cyclohexylmaleimide, N-2-methylcyclohexylmaleimide, N
-2-Ethylhexylmaleimide, N-decylmaleimide, N-dodecylmaleimide, N-cyclododecylmaleimide, N-octadecylmaleimide, N-phenylmaleimide, N-2-methylphenylmaleimide, N-4-
Isopropylphenylmaleimide, N-2,4-dimethylphenylmaleimide, N-benzylmaleimide, N-
Methyl-α-methylmaleimide, N-phenyl-α-methylmaleimide, N-phenyl-α-chloromaleimide,
Preferred examples include N-phenyl-α, β-dimethylmaleimide.

In the present invention, in order to polymerize an N-substituted maleimide compound to produce an N-substituted maleimide homopolymer, the N-substituted maleimide compound is subjected to known suspension polymerization, solution polymerization, or emulsion polymerization in the presence of a polymerization initiator. Alternatively, it can be obtained by polymerization such as bulk polymerization. Specifically, for example, the polymerization temperature is 0 to 120°C, particularly preferably 40 to 100°C.
It is desirable to carry out the polymerization within the range of 3 to 12 hours, and known organic peroxides or azo compounds can be used as the polymerization initiator. The amount of the polymerization initiator used is 0.0000000000 with respect to the N-substituted maleimide compound.
It is desirable that the amount is in the range of 0.01 to 5% by weight. The molecular weight of the obtained N-substituted maleimide homopolymer is not particularly limited, but the number average molecular weight is i, ooo-ioo, oo
A range of o is preferred. The number average molecular weight can be adjusted by adding a polymerization regulator such as mercaptans during polymerization.

The aluminum hydroxide used in the present invention is, for example, a commercially available product, Hisilite H310, 32 manufactured by Showa Light Metal ■.
There is 0. By using aluminum hydroxide as an inorganic filler, a deep translucent feel similar to natural marble can be obtained. When aluminum hydroxide is added to the resin composition, various fillers, polymerization inhibitors, internal mold release agents, binders, and plasticizers may be added before, after, or at the same time as necessary to the extent that the effects of the present invention are not impaired. It is also possible to add additives, flame retardants and fibrous reinforcing agents.

Other suitable fillers that can be used in combination with aluminum hydroxide include, for example, magnesium hydroxide, talc, clay, silica, calcium silicate, alumina, quartz, and glass powder. Preferred examples of the polymerization inhibitor include hydroquinone, benzoquinone, and t-butylcatechol. As the internal mold release agent, for example, stearic acid, zinc stearate, etc. can be used. Examples of thickeners include magnesium hydroxide and calcium hydroxide. Examples of the fibrous reinforcing agent include glass fiber, alumina whiskers, and aramid fiber.

The blending ratio of the unsaturated polyester resin, N-substituted maleimide homopolymer, aluminum hydroxide, and curing agent is not limited, but from the viewpoint of dispersibility of the mixture, low shrinkage of the molded product, and appearance, the unsaturated polyester resin 100 3 to 5 parts by weight of N-substituted maleimide homopolymer
The preferred range is 0 parts by weight, 30 to 300 parts by weight of aluminum hydroxide, and 1 to 3 parts by weight of the curing agent. If the proportion of the N-substituted maleimide homopolymer is less than 3 parts by weight, significant shrinkage occurs during molding. Moreover, if it exceeds 50 parts by weight, the appearance is unfavorable.

If the proportion of aluminum hydroxide is less than 30 parts by weight, shrinkage during molding and curing increases, and the resulting cured molded product is likely to be distorted. If the amount exceeds 300 parts by weight, the workability during dispersion of aluminum hydroxide may be reduced and the transparency of the resulting cured molded product may be impaired.

As the curing agent used in the present invention, common ones such as benzoyl peroxide, methyl ethyl ketone peroxide, lauroyl peroxide, bis-(4-butylcyclohexyl) peroxydicarbonate, and t-butyl peroxybenzoate can be used.
One or more of these can be used.

The molding method for the molding material for artificial marble of the present invention is a heat molding method including a hot pressure molding method, and a composition containing an unsaturated polyester resin, aluminum hydroxide, an N-substituted maleimide homopolymer, and a curing agent. 60-160
It may be molded and hardened in a molding die heated to ℃ or in an extruder.

(Effects of the invention) If the molding material for artificial marble of the present invention is used, it contains the four components specified above, so mass production is possible, it is translucent, has a glossy surface, has a small linear shrinkage rate, A molded artificial marble product with good heat resistance and a solid texture without warping or distortion can be obtained.

(Example) Hereinafter, the present invention will be specifically explained based on Examples.

Reference Example I Preparation of N-cyclohexylmaleimide Polymer In a four-bottle flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a Dimroth condenser, 1 part of partially saponified polyvinyl alcohol, 1 part of sodium lauryl sulfonate, and 400 parts of deionized water was charged and dissolved. Next, 100 parts of N-cyclohexylmaleimide was added to 1 part of methyl ethyl ketone.
00 parts solution and lauryl mercaptan 0.5 parts
A suspension solution was prepared under stirring. Next, 1.0 part of dibenzoyl peroxide as a polymerization initiator was dissolved in 5 parts of methyl ethyl ketone and added to the suspension solution, and then the temperature inside the system was raised to 80° C. to initiate polymerization. After continuing stirring for 8 hours, it was cooled to room temperature, the suspension was filtered, washed with water,
Thereafter, vacuum drying was performed to obtain an N-cyclohexylmaleimide homopolymer.

The yield was 86 parts, and the number average molecular weight was 18,000.

Reference Example 2 Preparation of N-phenylmaleimide homopolymer N-phenylmaleimide homopolymer having a number average molecular weight of 21,000 was prepared in the same manner as in Reference Example 1, except that N-phenylmaleimide was used instead of N-cyclohexylmaleimide. I got it.

Reference Example 3 Preparation of N-benzylmaleimide homopolymer N-benzylmaleimide with a number average molecular weight of 30,000 was prepared in the same manner as in Reference Example 1, except that N-penzylmaleimide was used instead of N-cyclohexylmaleimide. A homopolymer was obtained.

Reference Example 4 Preparation of N-dodecylmaleimide homopolymer A N-dodecylmaleimide homopolymer with a number average molecular weight of 52.000 was prepared in the same manner as in Reference Example 1, except that N-dodecylmaleimide was used instead of N-cyclohexylmaleimide. Obtained.

Examples 1 to 5 Unsaturated polyester resin (manufactured by Nippon Ubicar Co., Ltd., product name:
Yuvika 6500 (iso-based), aluminum hydroxide (manufactured by Showa Light Metal Co., Ltd., trade name Hisilite H310), and various N-substituted maleimide homopolymers were kneaded with DeSilver to obtain a molding material.

The artificial marble compound compounded in the proportions shown in Table 1 was injected into a 160 x 80 x 30 (ms) mold in advance and heated and molded at 60°C for 15 minutes. Linear shrinkage rate of the obtained artificial marble molded product The presence or absence of surface gloss was also measured.

Table 1 shows the formulation, molding conditions, and evaluation results of the obtained artificial marble.

Comparative Example I Instead of N-substituted maleimide homopolymer, particle size 10
A molding material was obtained using the same styrene polymer and operating in the same manner as in Example 1. Thereafter, the linear shrinkage rate and the presence or absence of surface gloss of the artificial marble molded product obtained in the same manner as in Example 1 were measured.

Table 1 shows the formulation, molding conditions, and evaluation results of the obtained artificial marble.

As can be seen from Table 1, compared to the molding material using the styrene polymer of Comparative Example 1, Examples 1 to 5 using the N-substituted maleimide homopolymer had a smaller linear shrinkage rate and an excellent glossy appearance. A molding material for artificial marble is obtained.

Claims (1)

[Claims] (1) Artificial marble containing an unsaturated polyester resin, 30 to 300 parts by weight of aluminum hydroxide, 3 to 50 parts by weight of N-substituted maleimide homopolymer, and a hardening agent based on 100 parts by weight of the unsaturated polyester resin. molding material.