JPS63110206A - Heat-resistant resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin, consisting of structural units of N-tert- butylmethacrylamide and structural units of styrene and methyl methacrylate and having excellent heat resistance, fluidity as well as colorability. CONSTITUTION:A linear random copolymer resin, consisting of (A) 20-90mol% N-tert-butylmethacrylamide expressed by formula I and (B) 80-10mol% one or more structural units of styrene and methyl methacrylate expressed by formula II or III and having 0.1-0.5 specific viscosity (etasp) (measured by using a solution in N,N-dimethylformamide solvent in 0.3% concentration at 30 deg.C). When the ratio of the units expressed by formula II in 100mol% monomer of the structural units (B) is 0-25mol%, transparency is excellent. When the ratio is 50-100mol%, fluidity is improved. The above-mentioned resin exhibits high heat resistance of about >=110 deg.C Vicat softening temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heat-resistant resin with improved heat resistance, fluidity, and colorability.

<Prior Art and Problems> Polystyrene resins and acrylonitrile-styrene copolymer resins, which are known as general-purpose resins, have excellent moldability but are poor in heat resistance. Conventionally, methods for improving heat resistance include a two-step method in which styrene is polymerized using maleic anhydride as a comonomer and then imidized (US Pat. No. 8,492,196), and methacrylic acid or α-methyl There is a method of using styrene etc. as a comonomer, but while these can improve heat resistance, the process is complicated, and the processability is significantly reduced due to the influence of the carboxyl group in the molecule. - When using methylstyrene, there are many problems such as coloring caused by acrylonitrile used to improve copolymerizability, and the heat resistance of these materials is also not sufficient.

As a result of intensive research to solve these problems, we found that the specific viscosity is 0.1 to 0.5, one or two monomers of Nt-butyl methacrylamide, styrene, and methyl methacrylate, and the necessary It has been discovered that a copolymer resin composed of other copolymerizable monomers has high heat resistance with a Vicat softening temperature of about 11 O''C or more, and has excellent fluidity and coloring properties, and the present invention It's arrived.

<Means for solving the problems> That is, the present invention has a specific viscosity of 0.1 to 0.5 and N-t
- linear random copolymer heat-resistant resin consisting of 20 to 90 mol% of butyl methacrylamide and 80 to 10 mol% of structural units of one or two monomers of styrene and methyl methacrylate; do.

The specific viscosity (ηsp) of the copolymer resin of the present invention is 0.1 to 0.
．． It is 5. The specific viscosity (ηsp) was measured using an Ostwald viscometer, and N,N-dimethylformamide solvent 0.3%, 3
This refers to the value measured at 0°C.

If the specific viscosity (ηsp) is less than 0.1, the fluidity will improve, but the molded product will become brittle, and if it is more than 0.5, the fluidity will be markedly reduced, which is not preferred.

The composition ratio of N-t-butylmethacrylamide represented by the structural unit (4) in the copolymer resin of the present invention is 20 to 9.
It is 0 mol%. If it is less than 20 mol %, the effect of improving heat resistance will not be exhibited so much, and if it is more than 90 mol %, the heat resistance will be improved but the molded product will become brittle (and fluidity will decrease).

In the present invention, styrene and methyl methacrylate, which have copolymerizability, heat resistance, and no problem in coloring, are selected as monomers to be copolymerized with N-t-butyl methacrylamide. However, if the proportion of the monomer styrene in the structural unit CB) is 0 to 25 mol%, the resulting copolymer resin will have good transparency;
00 mol%, more preferably 50 to 100 mol%, good fluidity is obtained.

Styrene as used in the present invention refers to styrene and nuclear-substituted styrenes such as parachlorostyrene, orthochlorostyrene, and paramethylstyrene.

In the present invention, other copolymerizable monomers that can be added as necessary include methacrylic acid, maleic anhydride,
There are monomers such as N-phenylmaleimide, α-methylstyrene, acrylonitrile, and methacrylate, and these can be used alone or in combination. The amount used is 0-1
5 mol% (total ioo mol% of monomers of structural unit (B)).

The method of copolymerization in the present invention is not particularly limited, and common suspension polymerization methods, emulsion polymerization methods, bulk polymerization methods, bath liquid polymerization methods, etc. can be used. In particular, a suspension polymerization method is preferred because of its simple wastewater treatment and drying steps.

In the reaction, known initiators such as peroxides and azo compounds are suitably used, and known redox initiators can also be used. Further, in the suspension polymerization method, emulsion polymerization method, etc., known dispersants and emulsifiers can be used.

The reaction is usually carried out at a temperature of 30 to 150°C for 1 to 15 hours. In addition, for controlling the molecular weight, known chain transfer agents such as t-dodecylmercaptan and 2-mercaptoethanol, and diallyl phthalate are used.

Known polyfunctional compounds such as diethylene glycol diacrylate and ethylene glycol dimethacrylate may be used during the production of the copolymer resin.

Furthermore, known lubricants such as behenic acid, stearic acid, and liquid paraffin may be added during the production of the copolymer resin.

The copolymer resin obtained in the present invention may be used alone or in a blend with the above-mentioned lubricants, known stabilizers, colorants, flame retardants, pigments, and various other polymers. Various polymers to be blended include polyvinyl chloride resin, chlorinated vinyl chloride resin, MBS resin, chlorinated polyethylene resin, acrylic rubber resin, NBR resin, polycarbonate resin, polyarylate resin, and polyamide resin. There are known resins such as engineering plastics.

The copolymer resin of the present invention is an injection method.

Can be processed and molded using a roll or extrusion molding machine. Further, as a product form, it can be used in the fields of plastic molded products and foam molded products.

<Examples> Examples of the present invention are shown below, but these do not limit the present invention.

The composition of the copolymer resin of the present invention was determined by elemental analysis and H-NMR. The heat resistance, fluidity, colorability, and transparency were measured by the following method after the resin was rolled and pressed.

Heat resistance: Vicat softening temperature (JIS-ni-7206) 5
kq/c-weighted flowability 2B method flow (JIS-7210), measurement temperature 240'C, 100kQ/d weighted transparency: JIS
-6714, the transmittance was measured and determined as follows.

Transmittance 85% or more 85-8080-7070% or less Symbol ◎ ○ △ × Colorability: Visually determined as follows.

Almost no coloration ◎ Very light yellow coloration ○ Yellow coloration △ Examples 1 to 3, Comparative Examples 1 to 2 600 g of deionized water in which polyvinyl alcohol o and 3y were dissolved in a 1e autoclave equipped with a stirrer. After adding a mixture of initiators in the proportions shown in Table 1 to 6 oy of Nt-butyl methacrylamide, 40 f of methyl methacrylate, and 100 parts by weight of the total monomers under stirring, the mixture was purged with nitrogen. After the temperature was raised to 90°C and polymerization was carried out for 7 hours, the temperature was further raised to 120°C and polymerization was carried out for 5 hours.

After rolling and pressing the obtained copolymer resin, heat resistance, fluidity, transparency, and colorability were measured.

As a comparative example, polymerization was carried out in the same manner using the initiators shown in Table 1, and then the physical properties were measured. The results are shown in Table 1.

Table 1 also shows the specific viscosity (ηSF) of each copolymer.

By comparing Margin Examples 1 to 3 and Comparative Examples 1 to 2 below, it was found that when the specific viscosity (ηsp) is smaller than 0.1, the fluidity improves, but it becomes brittle and cannot be molded; It can be seen that when it is larger, the fluidity is significantly reduced.

Examples 4 to 8, Comparative Examples 3 to 5 For 100 parts by weight of monomers having various compositions shown in Table 2,
0.10 parts by weight of benzoyl peroxide, 0.t-butylperoxy-8,5,5-)tumethylhexanoate.
After polymerizing in the same manner as in Examples 1 to 3 using 10 parts by weight, each physical property was measured.

In Comparative Examples, monomers having the composition shown in Table 2 were similarly polymerized, and then the physical properties were measured. The results are shown in Table 2.

Comparative Example 6 Styrene 701, methacrylic acid 30y1, benzoyl peroxide 0.8 parts by weight, t-butylperoxy-3,5
, 5-trimethylhexanoate o, i.

Part by weight of the mixed bath liquid was placed in an autoclave, the temperature was raised to 90°C after purging with nitrogen, and polymerization was carried out for 7 hours.
The temperature was raised to 0°C and polymerization was carried out for 4 hours. The resulting resin was pulverized, rolled and pressed, and then its physical properties were measured. The results are also listed in Table 2.

From Example 2.4.5 below, the heat resistance can be greatly improved as the composition ratio of Nt-butylmethacrylamide is increased, and compared to the polystyrene of Comparative Example 3, about 10°
It can be seen that the heat resistance can be improved compared to C and higher. It can also be seen that when the amount of N-t-butylmethacrylamide in Comparative Example 4 is less than 10 mol %, the effect of improving heat resistance is small, and in Comparative Example 5, the fluidity is significantly lowered and it is brittle. Example 6.
From 7, the styrene composition ratio in monomer (a) is 25 to 10.
It can be seen that when the content is 0 mol %, heat resistance can be maintained and fluidity can be greatly improved. From Example 8, 15 monomers (b)
It can be seen that when used in a mole % or less, heat resistance can be further improved without significantly reducing fluidity.

The copolymer resin of the present invention can significantly improve fluidity compared to the conventional method of improving heat resistance using methacrylic acid or the like as in Comparative Example 6 (Example 2.6.7.8).

Claims (5)

[Claims] (1) Formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ 20 to 90 mol% of the structural unit (A) represented by There is one or two types of structural units (B) 80-1 represented by ▼
It is a linear random copolymer consisting of 0 mol% and its specific viscosity (η_S_P) (N,N-dimethylformamide solvent 0
．． 3%, measured at 30°C) is 0.1 to 0.5. (2) The heat-resistant resin according to claim 1, wherein the proportion of ▲ showing mathematical formulas, chemical formulas, tables, etc. in 100 mol % of the monomer of the structural unit (B) is 0 to 25 mol %. (3) The heat-resistant resin according to claim 1, wherein the proportion of ▲ containing a mathematical formula, chemical formula, table, etc. in 100 mol % of the monomer of the structural unit (B) is 25 to 100 mol %. (4) The heat-resistant resin according to claim 3, wherein the proportion of ▲ containing mathematical formulas, chemical formulas, tables, etc. in 100 mol % of the monomer of the structural unit (B) is 5 to 100 mol %. . (5) Claim 1 obtained by suspension polymerization method
The heat-resistant resin according to any one of items 1 to 4.