JPH02169648A - Heat-and shock-resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition having well-balanced heat resistance and impact resistance by mixing a copolymer comprising methacrylamide and a styrene with a butadiene rubber. CONSTITUTION:A resin composition comprising 60-95wt.% copolymer comprising 5-60mol% methacrylamide, 95-40mol% styrene and 0-40mol% vinyl monomer copolymerizable therewith and 40-5wt.% butadiene rubber. Said styrene refers to styrene derivatives such as p-methylstyrene, p-chloromethylstyrene and p- chlorostyrene, and they can be used alone or as a mixture. When the amount of the copolymer used in said composition is below 60wt.%, the heat resistance improving effect is small, while when it is above 95wt.%, the impact resistance is low.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel resin composition having a good balance of heat resistance and impact resistance.

[Conventional technology and problems]

ABS resin is widely used in various fields, but it cannot be said that it has sufficient heat resistance.
Modified ABS resins in which α-methylstyrene, phenylmaleimide, etc. are introduced into S resin are being considered. Although the heat resistance of ABS is improved to some extent by the introduction of these compounds, it is not necessarily sufficient, and on the other hand, the introduction of these compounds presents a new problem in that the impact resistance is reduced.

[Means for solving problems]

In view of these circumstances, the present invention provides a novel resin composition that solves the above problems and has heat resistance and impact resistance in a well-balanced manner.

That is, the present invention provides a copolymer (A) 6 consisting of 5 to 60 mol% of methacrylamide, 95 to 40 mol% of styrene, and O to 40 mol% of a vinyl monomer copolymerizable with these.
0 to 95% by weight and butadiene rubber (B,) 40 to 5
The content is a resin composition consisting of 100%.

The styrene used in the present invention refers to styrene and known styrene derivatives such as p-methylstyrene, p-chloromethylstyrene, and p-chlorostyrene, which may be used alone or in combination.

Examples of the copolymerizable vinyl monomer used in the present invention include acrylic acid, an alkyl acrylic ester of acrylic acid and an alcohol having 1 to 18 carbon atoms, methacrylic acid, and a combination of methacrylic acid and an alcohol having 1 to 18 carbon atoms. There are known vinyl monomers such as alkyl methacrylic ester, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl ether compounds, acrylamide, t-phenylmethacrylamide, and N-t-butyl meccrylamide, which may be used alone or in combination. used in combination.

In the present invention, the amount of methacrylamide in the copolymer (A) is 5 to 60 mol%. If it is less than 5 mol%, the effect of improving heat resistance will be small, and if it exceeds 60 mol%, impact resistance will decrease. The preferred methacrylamide content of the copolymer (A) is 10 to 50 mol%.

When obtaining the resin composition of the present invention, the copolymer (A) may be polymerized separately from the butadiene rubber (B) and then blended, or the copolymer (A) may be blended with the butadiene rubber (B) in the coexistence (A) may be produced by polymerization.

Single methods for producing the copolymer (A) include conventional bulk polymerization methods and solution precipitation polymerization methods. Butadiene rubber CB)
As independent methods for producing , there are conventional solution polymerization methods and emulsion polymerization methods. The copolymer (A) and butadiene rubber (B) that have been separately obtained in this way are blended, and if necessary, the blend can be used in the form of pellets using an extruder.

When copolymer (A) is polymerized in the coexistence of butadiene rubber (B), butadiene rubber (B) is copolymerized with copolymer (A).
) The desired resin is obtained by dissolving the butadiene rubber (B) in the seven-mer composition mixture constituting the composition and then polymerizing it. In this case, a solvent may be used if necessary. Polymerization methods in this case include conventional bulk polymerization methods and solution polymerization methods.

The butadiene rubber (B) of the present invention refers to polybutadiene, a styrene-butadiene copolymer consisting of 20 to 40% by weight of styrene and 80 to 60% by weight of butadiene, and 15 to 40% by weight of acrylonitrile and 85 to 60% by weight of butadiene. at least one polymer selected from among these polybutadiene, styrene-butadiene copolymers, and acrylonitrile-butadiene copolymers.
80% by weight and 70 to 20% by weight of a mixture of styrene, methacrylic ester, acrylic ester, and other vinyl compounds copolymerizable with these are graft-polymerized. Here, the breakdown of this mixture is:
Suitable proportions include 20 to 80 parts by weight of styrene, 80 to 20 parts by weight of (meth)acrylic acid ester, and 0 to 40 parts by weight of other vinyl compounds.

The resin composition of the present invention comprises 60 to 95% by weight of the copolymer (A) and 40 to 5% by weight of the butadiene rubber (B), preferably 70 to 90% by weight of the former and 30 to 10% by weight of the latter.
Consisting of If the amount of copolymer (A) used is less than 60% by weight, the effect of improving heat resistance will be small, and if it exceeds 95% by weight, impact resistance will decrease.

The resin composition of the present invention is suitably used in fields requiring heat resistance and impact resistance. Molding methods for the resin composition of the present invention include extrusion molding, injection molding, calendar molding, roll molding, and blow molding. Known molding methods such as molding and press molding are used, and sheets,
Molded objects such as deformed products, hollow products, and pressed products can be obtained. In addition, in the present invention, stabilizers such as phenolic antioxidants, sulfur-containing antioxidants, and phosphorus-containing stabilizers, low molecular weight polyethylene,
There is no problem when using known lubricants such as paraffin wax, ester lubricants, and amide lubricants, known coloring agents such as batter pigments and inorganic pigments, and known fillers such as calcium carbonate, clay, and glass fiber. do not have.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these.

Reference Example 1: Production of copolymer (A) (continuous bulk polymerization method) A mixed solution of styrene, methacrylamide, and methyl ethyl ketone was continuously (
900 g/waiting time was supplied, and the reaction mixture was continuously taken out from the other side and led to a degassing tower to degas unreacted monomers and methyl ethyl ketone to obtain a copolymer. The polymerization temperature at this time was 150°C, and the temperature inside the degassing wound was 200°C.

Copolymers having the compositions shown in Table 1 were obtained by varying the mixing ratio of styrene, methacrylamide, and methyl ethyl ketone.

Table ■ MAM: Methacrylamide ST: Styrene MEK: Methyl ethyl ketone Reference example 2: Production of copolymer (A) (solution method R polymerization method) Styrene, methacrylamide, methacrylic acid, and methacrylic acrylate in a polymerization vessel with an internal volume of 201 tl thing 5hg,
Isopropyl alcohol Il, n-hexane 91. 10 g of benzoyl peroxide was charged and polymerized at 95° C. for 8 hours, followed by filtration and drying to obtain a powdery copolymer. The results are shown in Table 2.

Table 2 MAA: MMA methacrylate: Methyl methacrylate Reference example 3: Production volume of butadiene rubber (B) 121
In a polymerization vessel, 61 parts by weight of ion-exchanged water, butadiene, styrene, and 100 parts by weight of these mixed monomers, 0.2 parts by weight of diisopropylbenzene hydroperoxide, 0.04 parts by weight of ethylenediaminetetraacetate, and 1 part by weight of iron sulfate were added. , Rongalisoto 0.21℃
Add 2 parts by weight of sodium oleate and heat to 45°C.
The mixture was polymerized for 18 hours to obtain a styrene-butadiene copolymer.

Next, the same amounts of ethylenediaminetetraacetate, iron sulfate, and longalisotho as above were charged, and 0.2 parts by weight of cumene hydroperoxide was charged.

Raise the internal temperature to 60°C, add methyl methacrylate and styrene mixed monomer continuously over 5 hours, and then
After continuing polymerization for a period of time, the mixture was coagulated, dehydrated, and dried to obtain a butadiene rubber. Rubber copolymers shown in Table 3 were obtained by changing the seven-layer composition.

Table 3 B: Butadiene Examples 1 to 8, Comparative Examples 1 to 4 Nu (1) to (7) of copolymer (A) obtained in Reference Example 1
and butadiene rubber (B) of the butadiene rubber (B) obtained in Reference Example 3 were blended according to Table 4, and then pelletized using an extruder. This pellet was molded into l/4 using Nisshin Jushi Kogyo's FS-75 model molding machine.
An inch bar was prepared and the 1/4 inch bar was then used to measure the notched eye lift impact value according to ASTM D 256 and 18 inch according to ASTM 0648.
The heat distortion temperature at a load of 6 kg/- was measured. In addition, Irganox 1076 (trade name, Ciba Geigy@) and DSTP (trade name, Yoshitomi Pharmaceutical ■) are added as antioxidants per 100 parts by weight of resin during blending.
0.5 parts by weight of each were added. The results are shown in Table 4.

As is clear from Table 4, if the methacrylamide content in the copolymer is less than 5 mol%, the effect of improving heat resistance is small (Comparative Example 2), while if it exceeds 60 mol%, impact resistance decreases (Comparative Example 2). 1), and when the amount of copolymer used is less than 60% by weight, the effect of improving heat resistance is small (Comparative Example 3);
It can be seen that when the content exceeds 5% by weight, the impact resistance decreases (Comparative Example 4).

Examples 9 to 11 l1m of the copolymer (A) obtained in Reference Example 2 (8) to (I
O) and (a) to (c) of the butadiene rubber (B) obtained in Reference Example 3 were blended and pelletized in the same manner as in Examples 1 to 8, and after injection molding, the physical properties were evaluated. went. The results are shown in Table 5.

Table Example 12.13 A mixture of styrene, methacrylamide, methyl ethyl ketone, and SBS rubber (Kutuprene (A) Asahi Kasei Corporation ■) is continuously supplied to a loop-type continuous bulk polymerization vessel with an internal volume of 21, and polymerization is carried out from the other side. A mixed solution of unreacted monomers and solvent is taken out and led to a degassing tank, where unreacted monomers and solvent are degassed, and methacrylamide, styrene and SBS are removed.
A resin consisting of The physical properties of this resin were evaluated in the same manner as in the above examples. The results are shown in Table 6.

As is clear from Table 6, the resin obtained by copolymerizing methacrylamide with styrene in the presence of SBS rubber also has good heat resistance and impact resistance.

〔Effect of the invention〕

The resin composition of the present invention has a well-balanced heat resistance and impact resistance, and can be made into sheets, irregularly shaped products, hollow products, and pressed products by extrusion molding, injection molding, calendar molding, roll molding, blow molding, press molding, etc. It is molded into various molded bodies such as, and is widely used in fields where heat resistance and impact resistance are required.

Claims (1)

[Claims] 1. 5 to 60 mol% methacrylamide, 95 to 60 mol% styrene
40 mol%, and 60 to 95% by weight of a copolymer (A) consisting of 0 to 40 mol% of a vinyl monomer copolymerizable with these, and 40 to 5% by weight of a butadiene rubber (B). Resin composition. 2. The composition according to claim 1, wherein the copolymer (A) comprises 10 to 50 mol% of methacrylamide and 90 to 50 mol% of styrene. 3. The composition according to claim 1 or 2, wherein the amount of copolymer (A) used is 70 to 90% by weight.