JPS619459A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:The titled composition having excellent heat resistance, thermal decomposition resistance, and formability, comprising a polymer containing a methacrylimide structural unit at least in a specified amount and a vinyl polymer. CONSTITUTION:10-95wt% polymer which contains at least 5wt% methacrylimide structural unit of the formula [where R is an (un)substituted 1-20C alkyl or an aryl] and is obtained by the thermal decomposition condensation of methacrylic acid in the presence of an imidizing agent selected from among NH3 (a generator), a primary amine (a generator), etc., and 5-90wt% vinyl polymer (e.g. a PP or a styrene/acrylonitrile copolymer) are compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates to a novel thermoplastic resin composition having excellent heat resistance and thermal decomposition resistance.

(Prior Art) Vinyl polymerized thermoplastic resins such as polymethyl, metariflate, and polystyrene are generally widely used as general-purpose resins in home appliances, etc., but they have the disadvantage of insufficient heat resistance. There is.

An example of a method for improving the heat resistance of these vinyl polymerizable thermoplastic resins is disclosed in Japanese Patent Application Laid-open No. 1999-11-155-Ll.

A method of introducing maleic anhydride has been proposed as described in No. 2614 and JP-A-57-153008.

Generally, the copolymerization properties of maleic anhydride are quite different from those of other divinyl monomers, and in order to improve the copolymerization properties, it is said that it is preferable to use styrene as a copolymerization monomer.

In this case, a five-membered ring structure of maleic anhydride is introduced into the main chain of the maleic anhydride/styrene copolymer, thereby improving heat resistance. Examples of such polymers include methyl methacrylate/maleic anhydride/styrene copolymer or methyl methacrylate/maleic anhydride/styrene/a-methylstyrene quaternary copolymer.

(Problems to be Solved by the Invention) However, since these polymers are multi-component systems, it is difficult to manufacture them, their transparency cannot be improved, and furthermore, none of these polymers can be thermoformed. This has the fatal disadvantage that depolymerization reactions tend to occur near the temperature, resulting in the production of volatile matter, which significantly deteriorates the physical properties of the polymer itself.

(Means for Solving the Problems) The present inventors have arrived at this invention as a result of repeated testing and research in order to solve the above-mentioned conventional problems. Polymer 5 of a polymer having a structural unit content of 5% by weight or more and 10 to 95% by weight and (B) a vinyl monomer or a vinyl monomer mixture
It is a thermoplastic resin composition consisting of ~90 weight percent.

The polymer (A) containing the above-mentioned methacrylimide structural unit used in the present invention has a methacrylimide structural unit represented by the general formula (an alkyl group, an allyl group, or a mixture thereof).

There are no particular restrictions on the method for obtaining such a polymer, but a method of thermally decomposing and condensing a methacrylic resin using an imidizing agent selected from the group of ammonia, an ammonia generator, a primary amine, and a primary amine generator. (For example, U.S. Patent No. 214
6209, German Patent No. 1077872, German Patent No. 12
No. 42369).

The above-mentioned methacrylic resin used in obtaining the polymer containing the methacrylimide structural unit represented by the above general formula (1) is a methyl methacrylate homopolymer, or a methyl methacrylate and 75% by weight or less acrylic ester. Alternatively, there are copolymers with methacrylic acid ester, acrylic acid, methacrylic acid, styrene, methylstyrene, chlorostyrene, etc. Examples of the acrylic ester include methyl acrylate, ethyl acrylate, butyl acrylate, and t-butyl acrylate.

Nclohexyl acrylate, 2-ethylhexyl acrylate, benzyl acrylate, etc., and as a methacrylate ester, ethyl methacrylate.

Butyl methacrylate, t-butyl methacrylate.

Cyclohexyl tutaacrylate, 2-ethylcyclohexyl methacrylate, benzyl methacrylate, etc. are used, and these monomers may be used alone or in combination of two or more.

In this invention, if the content of the methacrylimide structural unit is less than 5% by weight, heat resistance will not be noticeable.

Next, the polymer (B) of the vinyl monomer or vinyl monomer mixture used in the present invention includes, for example, medium/low pressure polyethylene, high pressure polyethylene, polytube v+
1, +lr pyronyl chloride, polystyrene.

Poly, methyl succinate, polyurethane/tan, polyamide, polyacetal, polycarbonate, modified PPO,
PET, PPS, styrene/acrylonitrile copolymer, styrene/methyl methacrylate copolymer, Styrene
Examples thereof include α-, methyl styrene/acridonitrile/methyl methacrylate copolymer, α-, methyl styrene/acrydonitrile/methyl methacrylate copolymer, and the like.

In the resin composition of the present invention, the polymer (B) is 5
It is necessary that the content of (B) be in the range of ~90% by weight.
If the content of the component polymer is less than 5% by weight, good shaping processability cannot be obtained, and if it exceeds 90% by weight, the heat resistance decreases, and neither is suitable.

(Effects of the Invention) According to the thermoplastic resin composition of the present invention, the above-mentioned heat resistance is improved, and the heat decomposition resistance is also improved, as is clear from the Examples below. Since it has good processability without any loss, it is suitable for use in various molding materials, optical materials, films, etc., and can solve the above problems, and its industrial value is extremely large. . , (Example) The present invention will be specifically explained below with reference to Examples.

In the above Examples, the method for measuring the properties of the polymer is as follows.

Dissolution of the resin composition and its (A) and (13) component polymers at 1111 degrees: using a Koka type flow tester at a temperature of 200 degrees.
Measured at °C, Heat distortion temperature: Measured according to ASTM D-648-56, Intrinsic viscosity of polymer: Deereax
B15choff) Preparation of polymer (A) containing lλ krylimide structural units, measured with a viscometer. Sufficiently dried methyl methacrylate polymer J.

0 parts (parts by weight, same hereinafter), dehydrated and dried toluene 90
10 parts of dehydrated and dried methyl alcohol and 20 parts of methylamine were heated at 230°C with stirring in an autoclave.
The reaction was carried out for 5 hours. The obtained polymer was charged into an extruder and pelletized by extrusion molding at a resin temperature of 250° C. while degassing from the exhaust port.

Methacrylimide polymer pellets having the respective compositions shown in Table 1 were obtained in a similar manner.

However, in the above table, *1: Methyl methacrylate polymer (intrinsic viscosity -0.51) *2: Methyl meccrylate-styrene copolymer (weight ratio -90710, intrinsic viscosity 0.53) *3 = Methyl methacrylate -Butyl acrylate copolymer (weight ratio -80
720, intrinsic viscosity 0.31) A: Methyl meccrylate-methyl acrylate copolymer (weight ratio 80/20,
Intrinsic viscosity: 0.35) Examples 1 to 18 The component polymer (A) prepared as above and shown in Table 2 below (
t: component polymer (B) is blended in the proportions shown in Table 3,
This is melted into pellets using an extruder at a resin temperature of 250°C.
It became. Test pieces for measuring heat distortion temperature were prepared using an injection molding machine using the obtained pellets, and the heat distortion temperature (HDT) and melt viscosity of each test piece were determined and the results are shown in Table 3. As is clear from the results in the same table, it was clear that the resin composition of the present invention was significantly superior in heat resistance and melt fluidity compared to the resin composition ζ.

Table 3 ”HDT: Heat distortion temperature under load of 18,56 kg~1)

Claims (1)

Scope of Claims: (A) 10 to 95% by weight of a polymer containing 5% by weight or more of methacrylimide structural units, and (B) a polymer 5 of a vinyl monomer or a vinyl monomer mixture.
A thermoplastic resin composition consisting of ~90% by weight.