JPS60152513A - Production of cured acrylate resin object - Google Patents

Abstract

PURPOSE:To obtain a cured acrylate resin object excellent in appearance, heat resistance, etc., and suitable as a building material or the like, by mixing a polymerizable monomer based on methyl methacrylate with calcium aluminate hydrate and polymerizing the obtained mixture. CONSTITUTION:15-80wt% polymerizable monomer (prepolymer) based on methyl methacrylate and containing, if necessary, comonomers such as acrylic acid and vinyl acetate is mixed with 85-20wt% calcium aluminate hydrate. As the calcium aluminate hydrate, calcium aluminate hydrate represented by 3 CaO. Al2O3.6H2O can be suitably used, and a by-product from the production of alumina, etc., can also be used. A polymerization initiator (e.g., 2,2'-azobisisobutyronitrile) is added to the above mixture, and this mixture is polymerized by, for example, a bulk polymerization process to obtain the purpose cured acrylate resin object.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing filler-containing plastics useful in the construction industry that have improved appearance and heat resistance.

Filler-containing plastics are widely used as building materials and interior decoration. However, compared to natural stone, which has traditionally been used for building materials and interior decoration, plastics containing fillers are more flammable, have lower heat resistance, have poorer surface hardness, and do not have the same appearance as natural stone. There is a lot of room for improvement, such as the lack of depth.

Regarding internal cylinder combustibility of these improvements,
As seen in Japanese Patent No. 22586, a method is known in which a methyl methacrylate polymer is made flame retardant by incorporating an alumina hydrate therein. However, although alumina hydrate has excellent properties as a flame retardant, it decomposes at temperatures above 180°C, resulting in very poor heat resistance. Therefore, the alumina hydrate-containing methyl methacrylate polymer cannot be subjected to secondary processing such as heat bending that can be performed with ordinary polymers. Further, JP-A-56-9261 discloses an acrylic resin containing Sio2 and alumina hydrate.

However, SiO□ is not effective at all in making the material flame retardant and improving its heat resistance, and has the same drawbacks in terms of heat resistance as when it contains alumina hydrate.

Furthermore, in JP-A-52-16181, thermoplastic resins such as polystyrene, polyvinyl chloride, polyolefin, etc.
A composition obtained by melting and kneading O・A/20g・6H20 is described. However, these resins have poor surface hardness, heat deformation resistance, and weather resistance, and do not have sufficient performance as a substitute for natural stone.

Since it undergoes thermal decomposition, it is difficult to mix in fillers by melt mixing. Therefore, the present inventors investigated to obtain a cured acrylic resin product with excellent flame retardancy, heat resistance, surface hardness, and appearance. As a result, the present inventors preliminarily added calcium aluminate hydrate to a polymerizable monomer whose main component is methyl methacrylate. It has been discovered that this object can be achieved by polymerizing the materials after mixing them, leading to the present invention.

That is, the present invention uses 15 to 80% by weight of a polymerizable monomer containing methyl methacrylate as a main component or a partial polymer thereof.
This is a method for producing a cured acrylic resin by polymerizing a mixture of 20 to 85% by weight of calcium aluminate hydrate and calcium aluminate hydrate.

The cured acrylic resin obtained by the present invention has better flame retardancy, heat resistance, secondary processability, and better properties than conventional filler-containing plastics.
It has dramatically superior surface hardness and appearance.

Calcium aluminate hydrate in the present invention is OaO
There are various forms depending on the ratio of /Al2O3/H20, but the form expressed as 3CaO-kl,Os ・6H20'''Q is the most stable and easy to obtain form.8CaO・An
What is represented by zOs・6H20 is A10H)* and 0
The thermal decomposition temperature is as high as 250°C, and the X-ray diffraction absorption peak is also completely different from that of a material in which a(OH)2 is simply mixed at a molar ratio of 2=3.

The manufacturing method is l-GMELINS HANDBUCHDERA
NORG-ANISOHEN C! HEMIE ALU
MINIUM TEILBSYSTEM-NUMBER
85j (VERLAG CHEMIE G.

M, B, H, 1984), p. 560, shows that it can be obtained by the reaction of an aluminum compound and a calcium compound, but by-products from the production of alumina can also be used. The average particle size is preferably 8 μm or more and 80 μm or less, and if the average particle size is less than 3 μm, dispersibility during filling will be poor.
It becomes difficult to fill more than % by weight. Also, the average particle diameter is 80
If it is larger than ltm, separation from the matrix resin may occur due to sedimentation of particles during filling, which is not preferable.

As a polymerizable monomer mainly composed of methyl methacrylate, the resulting cured product has a similar appearance to natural stone, weather resistance,
From the viewpoint of surface hardness and heat deformation resistance, it is necessary to contain 50% by weight or more of methyl methacrylate units. If the amount is less than this, surface hardness, weather resistance, appearance, and heat deformation resistance cannot be ensured. In addition, in order to improve the thermal decomposition resistance of the methyl methacrylate polymer and the adhesion between the matrix resin and calcium aluminate hydrate, or to improve the moldability of the resulting cured product, less than 50% by weight of a polymerizable monomer may be added. Can be copolymerized. Monomers for copolymerization include methacrylic acid or acrylic acid (hereinafter referred to as (meth)acrylic acid), methyl acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, stearyl (meth)acrylate, Esters of (meth)acrylic acid and alcohol such as 2-ethylhexyl (meth)acrylate and 2-hydroxyethyl (meth)acrylate, (meth)acrylamide and its derivatives, styrene and its derivatives, vinyl acetate, etc. This can be given as a specific example.

Although the polymerizable monomer may be used as it is, it is more preferable to use a partial polymer in order to prevent the mixed calcium aluminate hydrate from being unevenly distributed.

The partial polymer may be one that is commonly used and is called syrup when producing methyl methacrylate (co)polymer.
The content of the polymer is about 3 to 40% by weight. 40% by weight
Exceeding this is not preferable because the viscosity becomes high and it becomes difficult to handle.

In addition, known methods may be used to produce this partial polymer, such as a method in which an initiator is added to a polymerizable monomer and polymerized, and the polymerization is stopped at an appropriate polymerization rate, a method in which a polymer of the monomer is There is a method of dissolving a predetermined amount of

To mix the polymerizable monomer or its partial polymer and calcium aluminate hydrate, put both in a container with a stirrer and mix them uniformly.
The method is not limited.

The amount of Naori lucium aluminate hydrate is 20% by weight ~
85% by weight is required. If it is less than 20% by weight, the flame retardance and heat resistance will be poor, and if it exceeds 85% by weight,
Not only is it difficult to mix uniformly with the polymerizable monomer or its partial polymer, but also the resulting cured product loses its secondary processability, which is undesirable.

As the polymerization method, bulk polymerization, suspension polymerization, etc. are applied.

Among these, bulk polymerization is preferred, and a method of casting polymerization in a mold is particularly preferred. In the cast polymerization method, a mold in the shape of a plate or a desired molded body is created, and in it, a polymerizable monomer mixture or a partial polymer of a polymerizable monomer mixture, a polymerization initiator, calcium aluminate hydrate, A predetermined amount of additives, etc. mixed is poured into the container and polymerized. Although the polymerization temperature and time vary depending on the type of shape initiator used in the molded article, it is generally carried out at 25°C to 95°C for 130 minutes to one week.

As the polymerization initiator, it is preferable to use a radical polymerization initiator such as an azo compound or an organic peroxide, and the amount thereof is preferably 0.001 to 1% by weight based on the polymerizable monomer, and more preferably 0.001 to 1% by weight based on the polymerizable monomer. It is preferable to add 0.01 to 0.5% by weight. Specific examples of azo compounds used as radical polymerization initiators include 2,2'-azobis(isobutyronitrile L2,2'-azobis(2,4-
dimethylvaleronitrile), 2,2'-azobis(2,
Examples of organic peroxides include benzoyl peroxide and lauroyl peroxide. Alternatively, a redox polymerization initiator, such as a combination of an organic peroxide and an amine, can also be used as a radical polymerization initiator. During this polymerization, additives commonly used in the production of methyl methacrylate polymers can be incorporated.

Its additives include crosslinking agents, ultraviolet absorbers, oxidation stabilizers,
One or more types of plasticizers, molecular weight regulators, colorants, etc. can also be used. As the crosslinking agent, commonly used crosslinking agents containing multiple polymerizable unsaturated bonds in one molecule can be used, such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate. Examples include acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, allyl(meth)acrylate, and the like. By adding a crosslinking agent, the surface hardness and solvent resistance of the molded article can be improved, and it can be used in an amount of 20% by weight or less based on the polymerizable monomer.

The ultraviolet absorber is added to improve the weather resistance of the IJ wax fat, and can be used in an amount of 5% by weight or less based on the amount of matrix resin. As oxidation stabilizers, there are those added to improve the weather resistance of the matrix resin and those added to prevent inhibition of polymerization by air during polymerization, and both are used in an amount of 5% by weight or less based on the amount of matrix resin. Plasticizers, molecular weight regulators, colorants, etc. can be added as necessary.

The present invention will be explained in more detail below with reference to Examples.

In the following examples, the oxygen index was measured according to JI8 7201, and the Rockwell hardness was measured according to ASTM D-785. The viscosity was measured at 25°C using an E-type viscometer (manufactured by Tokyo Keiki).

Example 1 Methyl methacrylate polymer (SumiPex BMH manufactured by Sumitomo Chemical) 121 was mixed with methyl methacrylate monomer 480
A methyl methacrylate partial polymer having a polymer content of 20% and a viscosity of 1 poise was obtained.

Above methyl methacrylate partial polymer 100g30a
O-AIj20. -6H20 (average particle size 12.um) 5
0f Ethylene glycol dimethacrylate-1-IF5.2'
-Azobisisobutyronitrile 0. IP The above mixture was placed in a 500 tRl glass flask and stirred with a stirring blade for 30 tRl.
Stir thoroughly for a minute.

A mold of 150×150×5 m/m was prepared, and the mixture was poured into it and polymerized by heating at 80° C. for 2 hours in a water bath.

The obtained cured product had an oxygen index of 26, a Rockwell surface hardness of 98 (M scale), and had excellent flame retardancy and surface hardness. The appearance was also left to my liking. This hardened product was heated in a hot air oven for 2
Although it was heated at 00°C for 120 minutes, there was no change in appearance such as swelling.

Example 2 Methyl methacrylate 892 f in 11 containers with a stirrer,
Methyl acrylate 8f to lauryl mercaptan 1.2
t,2,2'-azobisisobutyronitrile o,o2
y was added to obtain a partial polymer under zero nitrogen atmosphere.

, E partial polymer 100f 8 CaO-AR2os ・6HPO (average particle size 12.
um) 85g Triethylene glycol dimethacrylate'2fI Benzoyl peroxide 0.1g N,N-dimethyl-p-)luidine 0.051 The above mixture was thoroughly mixed with a stirring blade in a glass flask for 80 minutes, then 150x It was poured into a 150 x 5 m mold and left at room temperature for one day.

The obtained cured product had an oxygen index of 88 and a Rockwell surface hardness of 99 (M scale), showing excellent flame retardancy and surface hardness.

The cured product was heated at 200° C. for 80 minutes, but there was no change in appearance such as swelling.

Comparative Example 1 Partial polymer obtained in Example 2 1oop triethylene glycol dimethacrylate 2f benzoyl peroxide
0.3 g of the above mixture was added to a 0.05% by weight aqueous solution of hydroxyethyl cellulose, and suspension polymerization was carried out at 85° C. with vigorous stirring.

The obtained reta polymer 20y is 80aO-/J! 203°61
(After mixing with 2087f, roll mixer (Toyo Seiki 6)
The mixture was mixed using an inch roll) at 250°C, but the polymer did not melt and could not be blended.

Example 3 Methyl methacrylate polymer (Sumipex BMH manufactured by Sumitomo Chemical) 92F was mixed with methyl methacrylate monomer 312
A methyl methacrylate partial polymer having a polymer content of 23% and a viscosity of 2 poise was obtained.

The above partial polymer 800f 3CaO-IJ, 03-61 (20 (average particle size 12 μm
)50 f 2.2'-Azobisisobutyronitrile 0.21 The above mixture was thoroughly mixed in a 11-glass flask with a stirring blade for 30 minutes, poured into a mold of 250 x 250 x 6 m/m, and placed in a water bath. Polymerize by heating to 70°C for 4 hours. The appearance of the obtained cured product was good in both color tone and depth. The oxygen index of the cured product is 26, and the Rockwell hardness is 96.
(M scale), flame retardancy, and surface hardness were both excellent.

Comparative Example 2 Powdered methyl methacrylate polymer (SumiPex BMH manufactured by Sumitomo Chemical) 40F and 80aO-A1203
- After mixing 6H2010F, it was kneaded for 10 minutes at 230°C using a Plastomill (Brabender). The resulting polymer contained a large number of bubbles and a very fragile composition was obtained.

Example 4 Methyl methacrylate monomer 180 in 10F methyl methacrylate polymer (SumiPex BMH manufactured by Sumitomo Chemical)
f, 30 g of styrene monomer, and 5 f of ethyl acrylate were added and dissolved with stirring to obtain a partial polymer of polymerizable monomers.

Partial polymer of the above polymerizable monomer 1009a c
aO@Al2O3・6H,O (average particle size 12 μm) 1
80 g N,N-dimethyl-p-)luidine 0.1 g Benzoyl peroxide 0.15 f After thoroughly mixing the above mixture, pour it into a mold of 150 x 150 x 5 m/m.
It was left at °C for 1 day. The appearance of the obtained cured product was excellent, with an oxygen index of 80 and a Rockwell surface hardness of 90 (
M scale), showed excellent flame retardancy and surface hardness.

Procedural amendment (voluntary) March J, 1982 1. Display of incident 1981 Patent Application No. 9157 2. Name of the invention Manufacturing method of cured acrylic resin 3 Person making the amendment Relationship to the incident: Patent applicant Address: 5-15-5 Kitahama, Higashi-ku, Osaka, subject to correction Detailed description of the invention in the specification.

6, Contents of 7iJf l) From the 8th negative line 1 to the 3rd line of the specification, methacrylic acid is difficult. ” it says,
[Mafko Resin mainly composed of methyl methacrylate has a high softening point: dCaO・AI! If an attempt is made to melt and knead 203.6B20, 3CaO.A/zoa.6H20 will thermally decompose, so the method of melting and kneading cannot be used. ”
Change it to

2) "Insert 1-11 after CHIBMIEJ" on page 4, line 9 of the specification.

3) Details 1. In the 9th line of page 4, [TEILBJ] is corrected to [TEIL BJ.

4) Line 2 from the fourth negative mark of the specification, line 1θ of page 6, line 3 of page 7, line 7 of the same page, and line 9 of the same page. [preferably correct it to 1].

5) Details @ page 8, line 7 to line 9, 12
．． 2-Azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2-Azobis(2,4-
dimethyl-4-methoxyvaleronitrile) J and @iE
do.

6) Specification ajoa line to, line 18jj @ line 8,
In the 6th line of page 14 and the 9th line of the same page, the words ``Sumipex (SuBMB)'' are corrected to ``■'' ``Sumipex -B MHJ.''

7) On the 11th negative line 14th line of the statement, it says “1 chitso” 7j
-1 nitrogen”.

that's all

Claims (1)

[Claims] (1) A method for producing a cured acrylic resin by polymerizing a mixture of 15 to 80% by weight of a polymerizable monomer containing methyl methacrylate or a partial polymer thereof and 20 to 85% by weight of calcium aluminate hydrate .