JPS5991110A - Methacrylate polymer article and its production - Google Patents

Abstract

PURPOSE:To obtain the titled lightweight polymer article having high fire resistance and a translucent beautiful appearance, by pouring a mixture of a methacrylate-based polymerizable syrup and a specified amount of ettringite onto a casting surface, and molding the mixture by casting. CONSTITUTION:A mixture is prepared from a methacrylate-based polymerizable syrup containing 10-40wt% methacrylate polymer selected from the group consisting of a methyl methacrylate homopolymer and a copolymer of a methacrylate with an alpha,beta-ethylenically unsaturated compound (a syrup containing 10-40wt% methacrylate polymer dissolved in a methacrylate monomer), 20- 80wt%, based on the total weight of the mixture, ettringite, and a small amount, desirably 0.2-10wt%, of a catalyst for the syrup as a polymerization initiator. This mixture is poured onto the casting surface, and the poured mixture is cured by polymerization to obtain the desired cured product, namely the titled polymer article.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD This invention relates to filled methacrylate polymer plastic articles useful in the building industry and methods of making the same. Specifically, the present invention relates to ettringite (3CaO・Al
The present invention relates to a polymeric methacrylate article containing 10.3CaS0 .2B-311i 0), a methacrylate polymer article imparted with flame retardancy, and a method for producing the same.

[Background technology]

Adding inorganic substances to methyl methacrylate to produce hardened molded products with high translucency and an astronomical stone appearance is carried out industrially, for example, by blending large amounts of silica sand, calcined alumina, hydrated alumina, etc. .

However, in the case of polymerized hardened products to which inorganic substances such as silica sand and calcined alumina are added, when they are processed and used as building materials, the material is hard and brittle, which causes wear and tear on cutting tools and difficulty in processing. It had the disadvantage of lacking fire resistance, which is a very important characteristic as a building material.

In addition, in the case of a polymerized hardened product to which hydrated alumina is added, the workability is slightly improved, but in order to obtain sufficient fire resistance, hydrated alumina must be added at a high loading amount of 60% by weight or more. First, it generally leads to an increase in weight and a decrease in mechanical strength.

[Purpose of the invention]

The present invention was made to solve the above-mentioned drawbacks and inconveniences, and its purpose is to provide a methacrylate polymer article that is highly fire resistant, has a beautiful translucent appearance, and is lightweight. It's there.

[Disclosure of the invention]

As a result of intensive research to solve the above-mentioned drawbacks and inconveniences, the inventor of the present invention found that ettringite has high fire resistance, a beautiful translucent appearance, and is effective as an inorganic filler that reduces weight. I discovered something.

The methacrylate polymer article of the present invention is a composition comprising a methacrylate polymer and 20 to 80% by weight of ettringite based on the total amount of the mixture. - a polymerizable syrup of methacrylate containing 10 to 40% of a methacrylate polymer selected from copolymers with ethylenically unsaturated compounds (10 to 4% of a methacrylate polymer dissolved in methacrylate monomers)
0% by weight syrup), 20 to 80% by weight of ettringite, based on the total amount of the mixture, and a small amount, preferably 0.2 to 10% by weight, of a catalyst for syrup as a polymerization initiator. , the mixture is injected onto the casting surface, and the mixture is polymerized and cured to obtain the desired cured product.

Ettringite used as an inorganic filler has poor fire resistance when it is less than 20% by weight, and sufficient mechanical strength cannot be obtained when it is more than 80% by weight.

In the present invention, the methacrylate monomers include: ethyl methacrylate ethyl methacrylate probyl methacrylate methyl methacrylate ethyl acrylate butyl acrylate 2-ethylhexyl acrylate ethylene glycol dimethacrylate trimethylolpropane trimethacrylate hydroxypropyl methacrylate hydroxyethyl acrylate -dimethylaminoethyl Methacrylates include diethylaminoethyl methacrylate.

And ettringite as an inorganic filler is 3CaO
・AI 0・3CaSO・28-3100. The main component is ettringite, and some filler such as alumina hydrate or silica sand may be used therein. Ettringite as an inorganic filler is
Complete dryness is not a condition, and moisture adhering to the surface does not pose a particular problem in obtaining a cured product, and its amount can be allowed to be from 0 to 3% of the filler.

The catalyst for Shirabu as a polymerization initiator is active oxygen ft1
．． 16 to 12.4% and a half-life temperature of 185°C or less in 1 minute and 160°C or less in 10 hours, such as 2,4-dichlorobezoyl peroxide O-methyl benzoyl peroxide lauroyl peroxide benzoyl peroxide diacyl peroxide such as P-chlorobenzoyl peroxide dicumyl peroxide 2,5-dimethyl-2,5 di(tert-butylperoxy)-hexane 3-bis=(tert -Butylperoxy-isopropyl)-benzene tert-Butylcumyl peroxide and other dialkyl peroxides 1-di(tert-butylperoxy-3, 3,
5-trimethyl)-cyclohexane 1-di(tert-butylperoxy)-cyclohexane 2,2-di(tert-butylperoxy)-buta 4
・4-di(tert-butylperoxyvaleric acid-
〇-Butyl ester etc. Nopenny φ421K ter t-Butylperoxy-2-ethylhexanoate tert-Butylperoxy-hexahydroterephthalate ter t-Butylperoxy azelade ter
t-Butylperoxy-3, 5,5-trimethylhexo-1, tert-butylperoxyacetate-1-tert-
Examples include alkyl perester bis(4-tert-butylcyclohexyl) peroxydicarbonate such as butyl peroxymalate, tert-butylperoxybenzoate, tert-butylperoxyisopropyl carbonate, etc., and are selected from among these.

If desired, mercaptan chain transfer agents such as glycol dimercaptoacetate can be used.

A resin mixture composition of a polymerizable syrup of methacrylate as described above, 20 to 80% by weight of ettringite based on the total amount of the mixture, and a small amount of a catalyst for syrup as a polymerization initiator is prepared by rolling, kneading, etc. Using the mixture of the methacrylate polymers of the present invention, the mixture is thoroughly mixed with a mixer such as, etc., poured into a predetermined mold, and cured at a temperature of 25°C to 70°C to obtain the desired methacrylate polymerized product. All kinds of polymeric articles can be molded. Thus, the mixture can be poured into molds or onto textile, metal or glass layers to obtain useful products, or the mixture can be used as a laminate to wood or other plastics.

Next, an example will be described.

(Example) 85 parts of methyl methacrylate, 10 parts of ethyl acrylate
50% by weight of methyl methacrylate polymerizable silica containing 30% of a methacrylate polymer consisting of 5 parts and 5 parts of dimethylaminoethyl methacrylate in the monomer and 50% by weight of ettringite are thoroughly mixed in a kneader, and then 2 parts by weight based on the polymerizable silica are thoroughly mixed in a kneader. % of bis(4-tert-butylcyclohexyl) peroxyla carbonate,
After thoroughly mixing, the mixture was poured into a glass container coated with a silicone mold release agent, the upper surface of which was covered with a polyethylene terephthalate film, and the mixture was heated and cured in a 55° C. hot bath for 1.5 hours.

The cured product thus formed had self-extinguishing properties against flames, was translucent to light, and had a specific gravity of 1.40.

(Comparative Example) A similar hardened body was produced using 70% by weight of silica sand instead of the ettringite of the above example.

This cured product had no self-extinguishing property against flames and had a specific gravity of 1.82.

〔Effect of the invention〕

As described above, the methacrylate polymer article of the present invention has 20%
Since it is composed of ~80% by weight of ettringite, it has high fire resistance, a beautiful translucent appearance, and is lightweight.

patent applicant Matsushita Electric Works Co., Ltd. agent Patent Attorney Toshimaru Takemitsu (2 idiots)

Claims (1)

Claims: 1) A methacrylate polymer article comprising methacrylate polymer and 20 to 80% by weight of ettringite, based on the total weight of the mixture. 2) Mix a polymerizable silica based on methacrylate with 20 to 80% by weight of ettringite based on the total amount of the mixture and a small amount of the polymerization catalyst for the silica, pour the mixture onto the casting surface, and mix the mixture. A method for producing a methacrylate polymer article comprising a methacrylate polymer and 20 to 80 ffiff% of ettringite based on the total amount of the mixture, the method comprising curing and molding a methacrylate polymer article.