JPS6028862B2 - thermoplastic resin composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to a thermoplastic resin composition with excellent appearance.

A-prepared resin (acryonitrile-butane-styrene polymer) has excellent physical properties and is widely used in automobile parts and the like, but it has problems such as poor weather resistance and properties. On the other hand, polymers obtained by polymerizing aromatic vinyl compounds, vinyl cyanide compounds, and/or methacrylic acid ester compounds in the presence of an ethylene-propylene rubbery copolymer only have impact resistance and chemical resistance. It has excellent weather resistance and is expected to be used in a wide range of fields, including automotive exterior parts. However, this polymer has the disadvantage that flow marks and uneven gloss are likely to occur on the product surface during processing, particularly during injection molding.

Originally, this polymer has excellent weather resistance, so A
Unlike BS resin, it does not require surface treatment such as painting to improve weather resistance, and therefore the appearance of the molded product is of utmost importance. The present inventors have arrived at the present invention as a result of intensive research to solve these problems.

That is, the present invention involves polymerizing one or more compounds each selected from at least two groups of aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds in the presence of an ethylene-propylene rubbery copolymer. The resulting polymer has an intrinsic viscosity of 0.40 to 0.90.
A copolymer field obtained by polymerizing one or more compounds each selected from at least two groups of aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds; The object of the present invention is to provide a thermoplastic resin composition with an excellent appearance, which is characterized in that it is mixed into a thermoplastic resin composition. In the present invention, the ethylene-propylene rubbery copolymer refers to a binary copolymer (EPR) consisting of ethylene and propylene, and a ternary copolymer (EPDM) consisting of etherene, propylene, and non-conjugated ene.
etc., and one or more types may be used.

Non-conjugated dienes in EDPM include dicyclobentazine, ethylindenorbornene, 114-hexadiene, 115-hexadiene, 2-methyl-1,5-hexadiene, 1,4-cycloheptadine, and 1,5-cyclooctadiene. etc. EPR and EPD
Preferably, the molar ratio of ethylene to propylene in M ranges from 5:1 to 1:3.

Further, in EPOM, it is preferable that the proportion of non-conjugated gen is in the range of 2 to 50 in terms of iodine value.

Examples of the aromatic vinyl compound constituting the polymer and copolymer 'B' include styrene, Q-methylstyrene, Q-chlorostyrene, and vinyltoluene, with styrene being particularly preferred.

Acrylic is a vinyl cyanide compound.

Examples include nitrile and methacrylonitrile, with acrylonitrile being particularly preferred. Furthermore, examples of the methacrylic acid ester compound include methacrylic acid ester compounds such as methyl, ethyl, propyl, butyl, benzyl, and hexyl, with methyl methacrylate being particularly preferred. One or more compounds selected from at least two groups of the above-mentioned aromatic vinyl compounds, vinyl cyanide compounds, and other polymerizable monomer compounds are used.

The weight ratio of these compounds and the rubbery copolymer in the polymer composition can be varied within an appropriate range depending on the purpose.

Usually 5% to 4% by weight of the compound and 5% to 4% by weight of the rubbery copolymer.
6% by weight of the rubbery copolymer, preferably 5 to 25% by weight of the rubbery copolymer to 95 to 75% by weight of the compound. All known methods can be used to polymerize a compound in the presence of a rubbery copolymer to produce polymer (2).

Examples include suspension polymerization, bulk polymerization, emulsion polymerization, and solution polymerization. Moreover, the polymerization is not limited to one stage, but may be carried out in two or more stages. The copolymer [B) used in the present invention is a copolymer obtained by polymerizing one or more compounds selected from at least two groups among aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds. In particular, the intrinsic viscosity of the copolymer is important.

A copolymer having an intrinsic viscosity of 0.40 to 0.90 is used.

Note that the value of the intrinsic viscosity of the copolymer is a value measured at 30° C. in a dimethylformamide (DMF) solution. If the copolymer has an intrinsic viscosity of less than 0.4 degrees, the impact strength of the final composition will be significantly inferior, and if the intrinsic viscosity exceeds 0.90, it will be difficult to eliminate flow marks under normal molding conditions.

Although there is no particular limit to the composition of the copolymer, it is preferable that the amount of the aromatic vinyl compound is 60 to 75 percent by weight and the vinyl cyanide compound and/or methacrylic acid ester compound is 40 to 25 percent by weight.

As organic peroxides, alkyl hydroperoxides (
R-02H), peracid (RCO-02H), peracid ester (R-CO-02R'), alkyl peroxide (R-
02-R), acyl peroxide (RCO-Q-OCR)
), but polymer ■ and copolymer [B}
In consideration of mechanical mixing with a hydroperoxide, a hydroperoxide, a dialkyl peroxide, etc., which have a relatively high decomposition temperature, are preferable.

Further, from the viewpoint of operational safety, the half-life temperature for 10 hours is preferably 100 qC or higher. There is no particular restriction on the amount of organic peroxide used, but it is 0.01 to 2 parts by weight per 100 parts by weight of the total of the polymer and copolymer 'B'.

The composition of the present invention achieves the object of the present invention only by combining the above-mentioned polymer, a copolymer having a specific intrinsic viscosity, and an organic peroxide.

Examples of the mixing method for the polymer (1), the copolymer {B}, and the organic peroxide (C) include known mixing methods such as a Banbury mixer and an extruder.

It is also possible to add stabilizers, plasticizers, antistatic agents, lubricants, beam pigments, fillers, ultraviolet absorbers, etc. during mixing. Hereinafter, the present invention will be explained in detail with reference to Examples. Example 1 Polymer-EPDM (iodized with 8.0% Mooney viscosity of 61, proprene content of 4% by weight, containing ethylidene norbornene as a non-conjugated component).

) 2% by weight of styrene, 5% by weight of styrene and 2% by weight of acrylonitrile (bulk polymer product). - Copolymer {B} - 70% by weight of styrene and 3% by weight of acrylonitrile
A copolymer consisting of

B-1: Intrinsic viscosity 0.55 (suspension polymerization product) B-2: Intrinsic viscosity 0.35 (suspension polymerization product) B-3: Intrinsic viscosity 1
．． 10 (Emulsion polymerized product) - Organic peroxide 'q-dicumyl/
Gu oxide t-butyl peroxide Based on the composition ratio shown in Table 1, the above polymers and copolymers were kneaded using a Banbury mixer in the presence of an organic peroxide (sample numbers 1 to 5). I got it.

Additionally, pellets (sample numbers 6 and 7) were obtained in the same manner from only the polymer and copolymer. The obtained pellet was used to prepare a flat plate (7 skins x 12 arcs) and a test piece for surface appearance determination using a 5-ounce injection molding machine manufactured by Nissei Jushi Co., Ltd.

Table 1 shows the surface appearance and physical properties of the composition.

Table 1 *1 Flow marks are still observed, although they are less than those for 230oo molded products.

*2 Yellowing of the composition is observed.

Claims (1)

[Claims] 1 In the presence of an ethylene-propylene rubbery copolymer,
A polymer (A) obtained by polymerizing one or more compounds each selected from at least two groups among aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds, and an intrinsic viscosity of 0.40 to 0.90. A copolymer (B) obtained by polymerizing one or more compounds selected from at least two groups of aromatic vinyl compounds, vinyl cyanide compounds, and methacrylic acid ester compounds, and an organic peroxide (C ) A thermoplastic resin composition characterized in that it is mixed in the presence of.