JPH0248581B2 - NANNENSEIJUSHISOSEIBUTSU - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame-retardant resin composition obtained by blending an acrylic resin with an inorganic filler. More specifically, it is useful as an inexpensive and non-toxic decorative board material made by blending 10 to 50 parts by weight of aluminum hydroxide, 1 to 10 parts by weight of red phosphorus, and 100 to 200 parts by weight of alumina to 100 parts by weight of acrylic resin. The present invention relates to a flame retardant resin composition. Conventionally, the addition and mixing of organic halogen compounds or organic phosphorus compounds has been known as a method for making acrylic resin flame retardant, and some methods have been put into practical use, but the resulting composition is generally Many have poor properties or water resistance, smoke generation,
The issue of toxicity also remains. In addition, a method of blending alumina trihydrate with acrylic resin and making it flame retardant by utilizing the dehydration endothermic reaction of alumina trihydrate at combustion temperature (Special Publication No. 50-22586;
No. 21776) has been disclosed. However, according to additional tests conducted by the present inventors, this method requires the addition of 100 to 150 parts by weight or more to 100 parts by weight of acrylic resin in order to fully exhibit the flame retardant effect of alumina trihydrate. This has the drawback that the water resistance and surface hardness of the resulting resin composition are reduced accordingly. Furthermore, attempts have been made to make flame retardant by adding red phosphorus to general synthetic resins. For example, for epoxy resins, the combined effect of red phosphorus and aluminum hydroxide (Japanese Patent Publication No. 51-44040), polyphenylene oxide Regarding resins, a combination of red phosphorus and a molybdenum compound (JP-A-55-82152) has been disclosed, but it is difficult to make acrylic resins flame retardant with red phosphorus alone, and a large amount of addition is required. Due to the accompanying deterioration in physical properties, coloration, poor dispersion, etc., a satisfactory composition cannot be obtained, and it is also disadvantageous in terms of cost. There have also been attempts to create articles with a marble-like appearance by blending inorganic compounds such as alumina with acrylic resin (for example, U.S. Patent No. 3405088);
Many have poor flame retardancy and are unsatisfactory in appearance. On the other hand, it is well known that acrylic resins are highly used as various decorative materials due to their beauty, but their uses are limited because they are easily combustible. Therefore, imparting good flame retardancy has been desired by those concerned for a long time since it will enable application as a building material. In view of the above-mentioned current situation, the present inventors conducted intensive studies to obtain an inexpensive, non-toxic acrylic flame-retardant resin composition with excellent physical properties. The present invention was achieved by discovering that the present invention can be obtained. That is, in the present invention, 10 to 50 parts by weight of aluminum hydroxide, preferably 20 to 45 parts by weight, 1 to 10 parts by weight, preferably 3 to 8 parts by weight of red phosphorus, and 100 to 100 parts by weight of alumina are added to 100 parts by weight of acrylic resin. This is a flame-retardant resin composition containing 200 parts by weight, preferably 100 to 150 parts by weight. aluminum hydroxide 10
If the amount of aluminum hydroxide is less than 1 part by weight or the amount of red phosphorus is less than 1 part by weight, sufficient flame retardancy will not be obtained, and if the amount of aluminum hydroxide is more than 50 parts by weight or the amount of red phosphorus is more than 10 parts by weight, the water resistance of the resulting resin composition will decrease. However, the surface hardness also decreases. The use of alumina in combination is important, as it not only improves the water resistance, surface hardness, flame retardance, etc. of the resulting resin composition, but also has the effect of improving workability when inorganic substances with different specific gravity are used together to obtain a composition. It also has If the amount of alumina is less than 100 parts by weight, these remarkable effects will not be observed, and if it is more than 200 parts by weight, it will have an adverse effect on workability and reduce the impact strength of the resulting composition, which is not preferred. In the present invention, the acrylic resin refers to methyl methacrylate homopolymer, methyl methacrylate and α.β-
Copolymers with ethylenically unsaturated compounds such as acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, vinyl cyanide, aromatic vinyl, etc., and copolymers of these with divinylbenzene, allyl acrylate, polyethylene glycol dimethacrylate, trimethylol A general term for copolymers crosslinked with a crosslinking agent such as propane trimethacrylate. Naturally, the physical properties of the resulting resin composition are influenced by the type and degree of polymerization of these base polymers, but in particular copolymerization consisting of a dominant amount of methyl methacrylate, a minor amount of methacrylic acid, and a crosslinking agent. A combination is preferable because it has excellent chemical resistance. In an embodiment of the present invention, a mixture of these monomers and polymers, that is, a partial polymer of the monomers or a syrup in which the polymer is dissolved in the monomers, is prepared, and predetermined amounts of aluminum hydroxide, red phosphorus, After adding alumina and a known radical polymerization initiator, stirring and mixing thoroughly, pouring into a suitable mold and defoaming, heating at 30 to 90℃.
It can be obtained by heating polymerization and curing at a temperature of 100°C or higher, depending on the case. The polymer content in the syrup used in the present invention is 10
~35% syrup viscosity is 0.5~10 poise (25℃)
However, if the polymer content is too low and the viscosity is too low, it will take a long time to cure, which is not only economically undesirable, but there is also a risk of foaming.If the polymer content is too high and the viscosity is too high, the workability will be affected becomes worse. Therefore, when preparing a syrup of the base polymer, it is effective to control the degree of polymerization by a known method using a chain transfer agent. On the other hand, there are no particular restrictions on the form of the inorganic substance to be blended, but the average particle size is preferably 5 to 50 microns.Red phosphorus may be coated with a resin or not, and the amount added is determined by the amount of pure It can be blended as As a radical polymerization initiator, diisopropyl peroxydicarbonate, bis-4-t-butylcyclohexyl peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, t-butyl peroxypivalate, lauroyl peroxide, benzoyl peroxide,
Peroxides such as t-butylperoxy (2-ethylhexanoate), 2.2'-azobis-4-methoxy-2.4-dimethylvaleronitrile, 2.2'-azobis-2.4-dimethylvaleronitrile, 2.2'-azobis Azo compounds such as isobutyronitrile, redox initiators such as a combination of benzoyl peroxide and dimethyl para-toluidine, etc. are preferably used, and combinations of high temperature active initiators are also useful for improving the physical properties of the resulting resin composition. . As another embodiment for obtaining the resin composition of the present invention, for example, adding a compounding agent to the above polymer,
Kneader. A method of heating and mixing using a roll kneader, extruder, etc. is also possible. In addition to the above-mentioned inorganic substances, the resin composition of the present invention includes known fillers such as calcium carbonate, barium sulfate, titanium oxide, silicon oxide, mica, clay,
It is also possible to mix inorganic compounds such as talc, organic and inorganic dyes and pigments, various fibers, various stabilizers, and various dispersants. As described above, the resin composition obtained by the present invention has excellent flame retardancy, water resistance, surface hardness, etc., and can be used for sanitary wear, kitchen counters, table tops, tiles, etc. by using various molds. It can be useful as a decorative board material for top boards, wainscoting, etc. As will be described in detail in the examples below, the resin compositions in the examples were evaluated as follows. Flame retardancy: Test piece shown in UL94 (5 x 1/2 x
1/8 inch) was prepared, and a combustion test was conducted using a methane gas burner to determine the results. Surface hardness: Method specified in ASTMD785 (Rockwell hardness test method, M scale)
It was measured with Water resistance: A 2×2×1/8 inch flat test piece was immersed in boiling water for 2 hours, and the weight increase and appearance were examined. Examples 1 to 5 Aluminum hydroxide (Hygilite H-310 manufactured by Showa Denko) and alumina (A- 42) and red phosphorus (Rin Kagaku Nobalett #280A, pure
55%) in various proportions. After mixing thoroughly,
To 100 parts by weight of the mixture, 2 parts by weight of trimethylolpropane trimethacrylate, 0.05 parts by weight of lauroyl peroxide, and a small amount of silicone mold release agent were added, and after degassing under reduced pressure, the mixture was poured into two glass cells. , followed by heat curing at 80°C for 2 hours and then at 120°C for 2 hours. The evaluation results of the obtained resin compositions are shown in Table 1, including comparative examples. As is clear from Table 1, the composition of the present invention has excellent flame retardancy, hardness, and water resistance, and is useful as a decorative board material. Examples 6-7 Methyl methacrylate 95% by weight and methacrylic acid 5
By partially polymerizing the mixed monomers by weight%, the viscosity is 3poise
(25°C) syrup was obtained. Aluminum hydroxide, alumina, and red phosphorus were blended with 100 parts by weight of this syrup to prepare a resin composition in the same manner as in Examples 1 to 5. The evaluation results are shown in Table 2. These materials not only had excellent flame retardancy, hardness, and water resistance, but also had excellent chemical resistance, with no change in appearance after immersion in acetone for 50 hours, and a weight increase of 2 to 3% by weight.

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Claims (1)

[Claims] 1. A flame-retardant resin composition characterized in that 10 to 50 parts by weight of aluminum hydroxide, 1 to 10 parts by weight of red phosphorus, and 100 to 200 parts by weight of alumina are blended with 100 parts by weight of acrylic resin.