JPS62197408A - Thermoplastic copolymer resin composition - Google Patents

Abstract

PURPOSE:To improve the heat stability of an aromatic vinyl/maleimide copolymer containing a rubbery polymer, by using a diene component-free ethylene/ propylene rubber component as the rubbery polymer. CONSTITUTION:Ethylene/propylene rubber is mixed with a maleimide monomer (e.g., maleimide or N-methylmaleimide) and an aromatic vinyl monomer (e.g., styrene) at a predetermined weight ratio. this mixture is copolymerized by adding, if necessary, a polymerization initiator (e.g., benzoyl peroxide) thereto. In this way, the purpose thermoplastic copolymer resin composition comprising 5-35wt% ethylene/propylene rubber component, 5-60wt% maleimide monomer unit component and 90-5wt% aromatic vinyl monomer unit component can be obtained. This resin composition can be suitably used in the production of moldings in the field where heat resistance is required, such as domestic electrical appliances.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to thermoplastic copolymer resin compositions.

More specifically, the present invention relates to a thermoplastic copolymer resin composition with improved thermal stability.

[Prior art and its problems] A copolymer of styrene and maleimide containing a rubbery polymer is known as a heat-resistant resin (Japanese Unexamined Patent Publication No. 59-11
No. 322, Special Publication No. 8O-411i122).

However, this S+ resin has a problem in that as its heat resistance improves, its melt viscosity decreases, making it difficult to mold. In order to improve the moldability of resin,
It is necessary to raise the temperature during molding, but since diene rubber has traditionally been used as the rubbery polymer, it has poor thermal stability and cannot be heated to 70%, making it difficult to put it into practical use. It is in.

[Means for Solving the Problems] Therefore, the present inventors conducted extensive studies to improve the thermal stability of the rubber-like polymer-containing styrene-maleimide copolymer described above. As a result, it was surprisingly discovered that the object could be achieved by using ethylene propylene rubber containing no diene component as the rubbery polymer, and the present invention was completed based on this knowledge.

That is, the present invention provides a thermoplastic copolymer resin composition comprising an ethylene propylene rubber component, a maleimide monomer unit component, and an aromatic vinyl monomer unit component.

In the present invention, various kinds of aromatic vinyl monomers can be used as raw materials for aromatic vinyl monomer unit components, and specific examples include styrene, α-methylstyrene, t-butylstyrene, chlorostyrene, vinyltoluene, etc. Of these, styrene and α-methylstyrene are preferred.

Next, the maleimide monomer that is the raw material for the maleimide monomer unit component is represented by the following general formula.

RI R2 C--1C (However, in formula 1, R1* R2 and R3 are hydrogen, halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or an aryl group, and each may be the same or different. Specific examples of maleimide monomers include maleimide, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-laurylmaleimide F, N-phenylmaleimide F, N-(p -bromophenyl)maleimide, etc. Among these, maleimide, N-
Methylmaleimide and N-phenylmaleimide are preferred.

In addition, the ethylene propylene rubber component as a rubbery polymer can be arbitrarily used as long as it does not contain a diene component, and a commercially available product may be used as it is. 50～
A suitable proportion is 90% by weight, a propylene content of 50 to 20% by weight, and a Mooney viscosity NL+-4 (100° C.) of about 10-120 is used. If the ethylene content in the ethylene propylene rubber is less than 50% by weight, the impact resistance of the resulting resin composition will decrease, and if the ethylene content exceeds 90% by weight, the ethylene propylene rubber will become an aromatic vinyl monomer. It is not suitable because it becomes difficult to dissolve and causes the formation of gel in the resulting copolymer resin composition. Also, if ethylene propylene rubber with a Mooney viscosity of less than 10 is used, the resultant resin and In composition The use of ethylene propylene rubber with a Mooney viscosity of more than 120 is not suitable because the gloss and impact resistance of the resin composition are reduced.

There are no particular restrictions on the method for producing the copolymer resin composition of the present invention, but usually, 4 to 15 parts by weight of ethylene propylene rubber are mixed with 100 parts by weight of aromatic vinyl monomer, and then maleimide-based The fli polymer is added and the polymerization reaction is carried out until the conversion of the aromatic vinyl monomer reaches 30 to 90% by weight.

If the amount of ethylene or propylene rubber is less than 4 parts by weight, the resulting resin composition will have poor impact resistance, and if it exceeds 15 parts by weight, the heat resistance of the resin composition will decrease.

If the conversion rate of the aromatic vinyl single adhesion is less than 30% by weight, productivity will be poor, and if it exceeds 1%, the polymerization system will have high viscosity and the reaction will be non-uniform, resulting in This is not preferred because the physical properties of the resin composition deteriorate.

The polymerization reaction may be carried out in one reaction tank or in multiple stages,
In particular, a two-stage or three-stage continuous polymerization process is preferred. The polymerization tank used may be an ordinary polymerization tank, but a complete mixing type is particularly suitable, and is further equipped with, for example, double helical blades or Crawford-Russell blades. Preferably.

When adopting such a multi-stage continuous process, especially a two-stage continuous process, in the 1st fi combination tank of the 1st stage.

A mixed solution or solution obtained by mixing or dissolving 4 to 15 parts by weight of ethylene propylene rubber in 100 parts by weight of an aromatic vinyl monomer is supplied, and then a maleimide monomer is supplied into this first polymerization tank. However, preferably 100 to 13
At 0°C, the conversion rate of aromatic vinyl oxide is preferably 10
The polymerization reaction is carried out until the concentration is ~40% by weight.Then, the entire amount of the polymerization reaction product is transferred from the second first polymerization tank to the second stage second polymerization tank, and the maleimide monomer is further added to this second polymerization tank. While feeding, the polymerization reaction is preferably carried out at 110 to 150° C. until the conversion rate of the aromatic vinyl #11 monomer becomes 30 to 90% by weight.

In this two-stage continuous process, the polymerization reactions are bulk polymerization,
Either solution polymerization may be used, but bulk polymerization is preferred since it eliminates the need for solvent recovery and separation.

In starting the polymerization reaction, for example, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, di-t-butyl peroxide, t-
Butyl peroxybenzoate, dicumyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, diisopropyl peroxydicarponate, t-butyl peroxypivalate.

Stearoyl peroxide, 1,1-bis-(t-
butylperoxy)-1,3,5-)limethylcyclohexane, 1,1-bis-(t-butylperoxyoctane), n-butyl-4,4-bis-(1-butylperoxy)valerate, Polymerization initiators such as 2.2-bis-(t-butylperoxy)butane, di-t-butyldiperoxyisophthalate), and 2.5-dimethyldi(benzoylperoxy)hexane may be added.

After the completion of the polymerization reaction, one polymerization reaction product is usually transferred from the polymerization tank to a heater and a deaerator, preferably at a temperature of 150 to 290 ml.
The unreacted aromatic vinyl monomer is recovered by degassing at 500 s/Hg or less, and when a solvent is used, the solvent is also recovered, and a pelletized resin is obtained using an extruder.

The resulting copolymer resin composition includes a copolymer 1 of an aromatic vinyl monomer and a maleimide monomer, such as styrene-
N-phenylmaleimi)'jt[N-phenylmaleimi)'jt[In 4, ethylene-propylene rubber containing the copolymer absorbed therein is dispersed and contained.

The content of each component in the copolymer resin composition of the present invention obtained as described above is 5 to 35% by weight of the ethylene propylene rubber component, 5 to 90% by weight of the maleimide-based seven-unit component,
The aromatic vinyl nitrate unit component should be 90 to 5% by weight. If the ethylene propylene rubber component is less than 5% by weight, the impact resistance of the copolymer resin composition will decrease, and if it exceeds 35% by weight, the heat resistance will decrease, which is not preferable. If the unit component is less than 5% by weight, the heat resistance of the resulting copolymer resin composition will decrease, and if it exceeds 90% by weight, the impact resistance will decrease, which is not preferable. If it exceeds 90% by weight, the impact resistance of the copolymer resin composition will decrease, and if it is less than 5% by weight, the heat resistance will decrease, which is not preferable.

Particularly preferable contents of each component are 10 to 40% by weight of the ethylene propylene rubber component, 10 to 40% by weight of the maleimide monomer unit component, and 90 to 30% by weight of the aromatic vinyl monomer unit component.

[Effects of the Invention] In the present invention, a resin composition with improved thermal stability can be obtained by using ethylene propylene rubber as a rubbery polymer as a component of a rubbery polymer-containing thermoplastic copolymer resin composition. can. Therefore, the resin composition of the present invention is suitable for producing molded products in fields where heat resistance is required, such as home appliances.

[Example] Next, the present invention will be explained in detail with reference to examples.

Examples 1 to 4 First polymerization tank (capacity 1.8N) equipped with double helical salt
It consists of a continuous two-stage tank type reaction tank in which a second ff1 combining tank (capacity 2.8 f), which is also equipped with a double helical Polymerization was carried out using a polymerization reactor.

Ethylene propylene rubber was supplied and dissolved together with styrene into a rubber dissolving tank in an amount of 4 to 15 ffl parts per 1001 parts of styrene, and this solution was continuously supplied to the first polymerization tank at a flow rate of 1 i'/hr. . On the other hand, this first
N-7 enylmaleimide was introduced into the polymerization tank at the ratio shown in Table 1, and the mixture was heated to 110 to 140°C to polymerize to a predetermined monomer conversion rate. At the same time, the reaction product was transferred from the first polymerization tank to the second polymerization tank, and N-phenylmaleimide was supplied to this tank at the ratio shown in Table 1 and polymerized by heating at 120 to 150°C.

The reaction product is continuously extracted from the second polymerization tank.

After removing residual volatile matter using a deaerator, the polymer was pelletized. Yellowness (Yl) of this pellet (JIS K
7105), and then the pellets were
After residence in the extruder for 30 minutes at 0°C.

Measure the YI of the pelletized material, and calculate the difference in ΔYI
It was expressed as The results are shown in Table 1.

Comparative Examples 1 and 2 Comparisons were carried out in the same manner as in Example 1 except that polybutadiene or ethylene propylene diene rubber was used as the rubbery polymer. The results are shown in Table 1.

Claims (2)

[Claims] (1) A thermoplastic copolymer resin composition comprising an ethylene propylene rubber component, a maleimide monomer unit component, and an aromatic vinyl monomer unit component. (2) The thermoplastic copolymer according to claim 1, comprising 5 to 35% by weight of an ethylene propylene rubber component, 5 to 60% by weight of a maleimide monomer unit component, and 90 to 5% by weight of an aromatic vinyl monomer unit component. Coalescent resin composition.