JP3206076B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has excellent heat resistance, workability, chemical resistance and impact resistance, and has good mold release properties.
The present invention relates to a thermoplastic resin composition useful for electric products, automobile parts, and the like.

[0002]

2. Description of the Related Art Heretofore, research and development of a blended resin of a maleimide-based copolymer and an AS resin or an ABS resin (hereinafter sometimes referred to as "maleimide-based copolymer composition") has been actively conducted. Since this maleimide copolymer composition is particularly excellent in heat resistance, it is used in automobile parts and home electric parts in place of parts in which a modified polyphenylene ether resin or the like is conventionally used due to insufficient heat resistance of ABS resin. Research and development are underway for the purpose.

[0003] In recent years, the use of such components has been increasing in size and complexity, and some molded articles have a problem of cracking at the time of release from a mold. Regarding this mold release defect,
A method of applying a release agent to a mold cavity is generally performed by a molding manufacturer. However,
In recent years, automatic unmanned operations have been increasing in molding processing manufacturers, and molding may not be actually performed with molding materials that require application of a release agent. For this reason, the releasability of the molding material is an important required property as well as the material properties. In particular, a composition comprising a maleimide-based copolymer containing a vinyl cyanide monomer as an essential component and a rubber-modified styrene-based thermoplastic resin has excellent heat resistance, chemical resistance, impact resistance, and processability. But the releasability is not sufficient.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and comprises a maleimide copolymer containing a vinyl cyanide monomer as an essential component and a rubber-modified styrene thermoplastic resin. By blending a small amount of an organic polysiloxane as a third component into a composition comprising: a thermoplastic resin composition having excellent heat resistance, workability, chemical resistance, impact resistance, and mold release properties. To provide.

[0005]

The present invention provides (I) (a) N
5 to 50% by weight of a substituted maleimide monomer, (b) 10 to 94% by weight of an aromatic vinyl monomer, and (c) 1 to 40% by weight of a vinyl cyanide monomer [where (a) + ( b) +
(C) = 100 wt%] of copolymerizing a maleimide copolymer 5 parts by weight or more but less than 50 parts by weight obtained, (II) a rubber-modified styrene thermoplastic resin 95 parts by weight or less to 50 fold
Parts by weight and (III) the organopolysiloxane in an amount of 0.1 to 100 parts by weight based on the total amount of the components (I) to (II).
It is intended to provide a thermoplastic resin composition containing more than 05 parts by weight and not more than 3.0 parts by weight.

First, (I) N-substituted maleimide monomers (a) used in maleimide copolymers include N-alkylmaleimides having an alkyl group having 1 to 4 carbon atoms,
-Phenylmaleimide, N-substituted phenylmaleimide,
Examples thereof include N-cyclohexylmaleimide, and preferred are N-phenylmaleimide and N-cyclohexylmaleimide. (A) Examples of the N-substituted maleimide monomer include those obtained by copolymerizing maleic anhydride and imidizing with aniline or the like.

Also, (I) the aromatic vinyl monomer (b) used in the maleimide-based copolymer includes styrene,
α-methylstyrene, α-chlorostyrene, bromosty
Len, p-methylstyrene and the like can be mentioned, and one kind or a mixture of two or more kinds is used. Particularly, styrene and α-methylstyrene are preferred. Further, (I) vinyl cyanide monomer (c) used in the maleimide-based copolymer includes acrylonitrile, methacrylonitrile, maleonitrile and the like, and these may be used alone or in combination of two or more. Used. In particular, acrylonitrile and methacrylonitrile are preferred.

The amount of the (a) N-substituted maleimide monomer is from 5 to 50% by weight, preferably from 10 to 50% by weight, based on the component (I).
When the content is less than 5% by weight, the effect of improving heat resistance is small. (B) The amount of the aromatic vinyl monomer to be used is 10 to 94% by weight, preferably 20 to 85% by weight in the component (I). If the amount is less than 10% by weight, the processability is reduced. %, The impact resistance decreases. (C) The amount of the vinyl cyanide monomer used is 1 to 40% by weight, preferably 5 to 35% by weight in the component (I),
If it is less than 1% by weight, heat resistance, impact resistance and chemical resistance are reduced, while if it exceeds 40% by weight, workability and releasability are reduced. (I) The maleimide-based copolymer has the above (a) to
(C) It is obtained by copolymerizing a monomer component containing a monomer, and its polymerization method includes emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like. The limiting viscosity (in methyl ethyl ketone, 30 ° C.) of the maleimide-based copolymer (I) used in the present invention is usually 0.3 to 0.9 dl.
/ G.

Next, the (II) rubber-modified styrenic thermoplastic resin used in the present invention is preferably an aromatic vinyl monomer or an aromatic vinyl monomer and another vinyl monomer in the presence of a rubbery polymer. What is obtained by what is called a graft copolymerization prescription in which a monomer is graft-copolymerized is preferable.
Further, a rubber-modified styrene-based thermoplastic resin (graft copolymer) obtained by the graft copolymerization prescription is mixed with a styrene-based (co) polymer obtained by a separate method. A thing may be used.

Here, the rubbery polymer includes polybutadiene, styrene-butadiene copolymer, acrylic copolymer, hydrogenated diene copolymer, ethylene-propylene copolymer, chlorinated polyethylene, and polyurethane. Although polybutadiene is particularly preferred. (II) The preferred particle size of the rubber component of the rubber-modified styrenic thermoplastic resin is at least 50% by weight of 1,200 to
1,500 °, more preferably at least 70% by weight of 1,200 to 2,500 °.

The aromatic vinyl monomer used in the rubber-modified styrene-based thermoplastic resin (II) is the same as the component (a) used in the component (I), but is preferably used. Is styrene, α-methylstyrene, bromostyrene and p-methylstyrene. Further, other copolymerizable vinyl monomers other than the aromatic vinyl monomer include the same N-type as the component (a) used in the component (I).
In addition to the substituted maleimide monomer and the same vinyl cyanide monomer as the component (c), methyl methacrylate, ethyl methacrylate, maleic anhydride, methacrylic acid, methyl acrylate, ethyl acrylate and the like are used.
(II) Resin component other than rubbery polymer of rubber-modified styrene-based thermoplastic resin (graft component + matrix component)
Preferably comprises an aromatic vinyl monomer and a vinyl cyanide monomer, and the composition ratio thereof is preferably 60 to 9
0/40 to 10 wt%, more preferably 65-85 /
35 to 15% by weight. Within this composition range, impact resistance is further improved.

Specific examples of the rubber-modified styrene-based thermoplastic resin (II) thus obtained include a conventional acrylonitrile-butadiene-styrene resin (ABS resin) and an acrylonitrile-ethylene-propylene-styrene resin (AES resin). And methyl methacrylate-butadiene-styrene resin (MBS resin), acrylonitrile-butadiene-methyl methacrylate-styrene resin (transparent ABS resin), and rubber-modified polystyrene (high impact polystyrene; HIPS). (II) The rubber content in the rubber-modified styrene-based thermoplastic resin is preferably 5 to 40% by weight, more preferably 10 to 30% by weight. (II) The intrinsic viscosity [η] of the rubber-modified styrene-based thermoplastic resin measured at 30 ° C. in methyl ethyl ketone is preferably 0.2 to 1.2 d.
1 / g, more preferably 0.3 to 1.0 dl / g. Further, (II) the graft ratio, as measured by solvent fractionation of the rubber component of the graft polymer in the rubber-modified styrene-based thermoplastic resin with acetone or the like, is preferably 1
It is 0 to 150%, more preferably 20 to 100%.

Next, the organopolysiloxane (III) used in the present invention has the following general formula: (Wherein, R ¹ and R ² are the same or different and each represents an alkyl group, an aryl group, or an aralkyl group).

The organic polysiloxane (III) may be partially substituted with a hydroxyl group, an alkoxy group, a hydroxyalkyl group or the like. These (III) organopolysiloxanes may be used alone or in combination of two or more. Specific examples of the (III) organic polysiloxane include methylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane, and the like. (III) The viscosity of the organic polysiloxane is not particularly limited, but is preferably 110 to 100,000 cst (30
C), more preferably 100 to 20,000 cst.

The thermoplastic resin composition of the present invention comprises the above components (I) to (III) as main components.
(I) Maleimide-based copolymer is at least 5 parts by weight to 50 parts by weight
Less than 10 parts by weight , preferably from 10 parts by weight to less than 50 parts by weight ,
(II) rubber-modified styrene-based thermoplastic resin is 95 parts by weight or less
Bottom to more than 50 parts by weight , preferably 90 parts by weight or less
An amount exceeding 50 parts by weight [(I) + (II) = 1]
00 parts by weight], and (III) the organopolysiloxane is as defined in (I) above.
More than 0.05 part by weight and not more than 3.0 parts by weight, preferably 0.1 to 2.0 parts by weight, per 100 parts by weight of the total amount of the components (II)
Parts by weight. (I) the amount of component is less than 5 parts by weight is insufficient improvement in heat resistance, while the 50 parts by weight or more
Is not practical due to reduced workability. When the amount of the component (II) is less than 50 parts by weight, the impact resistance is low.
If it exceeds 5 parts by weight, the heat resistance will decrease. Furthermore, (III)
When the amount of the component is 0.05 part by weight or less with respect to 100 parts by weight of the total amount of the components (I) to (II), the effect of improving the mold releasability is not exhibited. However, the effect of mold releasability will level off and it is not economical.

The thermoplastic resin composition of the present invention comprises the above-mentioned components (I) to (III) as main components, and if necessary, further includes a lubricant, an antistatic agent, an antioxidant, a flame retardant, and an ultraviolet absorber. It is possible to mix inorganic antioxidants, colorants, inorganic fillers such as glass fibers, and other additives and additives commonly used in this type of thermoplastic resin composition.

In the mixing of the thermoplastic resin composition of the present invention,
Banbury mixer, Brabender, plast mill, kneader, various extruders and the like can be used various mixing devices and methods generally used for mixing thermoplastic resins, among these, using a vented extruder The method is preferred. The form of each resin component before mixing is not particularly limited. For example, any form such as pellets, beads, powders, and flakes can be mixed, but the mixing temperature is determined by mixing (I ) The temperature must be equal to or higher than the melting point of the maleimide-based copolymer, and therefore, the mixing temperature is preferably 200 ° C or higher.

[0018]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. In the examples, parts and% are based on weight unless otherwise specified.
Various measurements in the examples were based on the following methods. Physical properties of a test piece injection molded at an Izod impact strength and a heat deformation temperature of 260 ° C. were measured under the following conditions. Izod impact strength; ASTM D256 (1/4 ")
Notched) Heat distortion temperature; ASTM D648 (1/2 ", 18.6)
kg / cm ² ) Melt flow rate Measured at 240 ° C. under a load of 10 kg according to JIS K7210.

Evaluation of mold releasability Molding was performed using the mold shown in FIG. 1, and the number of whitened portions of 14 protruding pins was counted and evaluated according to the following criteria. Number of whitening points Evaluation point 0-2 ◎ 3-5 ○ 6-10 △ 11-14 ×

Reference Example 1 [(I) Preparation of Maleimide Copolymer] Into a 5 liter reactor equipped with a stirrer and a plate baffle, 50 parts of pure water and 0.2 parts of potassium persulfate were charged and reacted. After replacing the inside of the vessel with nitrogen gas,
The temperature was raised to 0 ° C. To this reactor, a mixture of 0.1 part of t-dodecylmercaptan, 1 part of sodium dodecylbenzenesulfonate, 100 parts of pure water and the monomers shown in Table 1 was continuously added over 5 hours. Thereafter, the temperature was raised to 80 ° C. and aging was performed for 2 hours to obtain a latex. An aqueous calcium chloride solution was added to the obtained copolymer latex for coagulation treatment, and the product was recovered.

[0021]

[Table 1]

Reference Example 2 [(II) Preparation of Rubber-Modified Styrenic Thermoplastic Resin] ABS Resin 1: 40 parts of polybutadiene rubber and styrene 4
A graft polymer obtained by graft-polymerizing 5 parts and 15 parts of acrylonitrile. Graft ratio = 50%, [η] (Intrinsic viscosity of methyl ethyl ketone soluble matter) = 0.5 dl / g AS resin 1: 75 parts of styrene and acrylonitrile 2
AS resin consisting of 5 parts. [Η] (Intrinsic viscosity of methyl ethyl ketone soluble matter) = 0.6 dl / g

Reference Example 3 [(III) Preparation of Organic Polysiloxane] C-1: Methylpolysiloxane, viscosity = 200 cst
(30 ° C.) C-3; diphenylpolysiloxane, viscosity = 1,000
cst (30 ° C)

Examples 1 and 2 and Comparative Examples 1 to 8 The components (I) to (III) were mixed in a Henschel mixer according to the formulation shown in Tables 2 to 3, and the mixture was further heated to 230 to 260 ° C. using a twin screw extruder. Pellets were produced at the following temperatures. The pellets were injection molded at 260 ° C., and the Izod impact strength and the heat distortion temperature were measured. The mold releasability was evaluated by molding using the mold shown in FIG. 1 as described above. The results are shown in Tables 2 and 3.

As is clear from Table 2, Examples 1 to2
Is a composition of the present invention, and has good physical properties and mold release.
The properties are also good. In contrast, Table 3 clearly shows
In Comparative Example 1, (III) the organopolysiloxane of the present invention
This is a case where the amount is out of the range and is small, and the mold releasability is inferior. ratio
Comparative Example 2 shows that (III) the organopolysiloxane is within the scope of the present invention.
In many cases, mold release properties have reached a plateau
You. Comparative Example 3 shows that the vinyl cyanide monomer was within the scope of the present invention.
This is an example in which the component (I) is used in an amount less than
Poor thermal properties.

Comparative Example 4 is an example in which N-phenylmaleimide uses the component (I) which exceeds the range of the present invention, and is inferior in impact resistance and moldability. Comparative Example 5 is an example using the component (I) in which the cyan vinyl monomer exceeds the range of the present invention and the amount of styrene is less than the range of the present invention. Is inferior. Comparative Example 6 is a case where the content of the aromatic vinyl monomer (b) of the component (I) exceeds the range of the present invention, and the impact resistance and the heat resistance are inferior. Comparative Example 7
This is an example in which (c) a vinyl cyanide monomer is not used as the component (I), and the impact resistance and heat resistance are poor. Comparative Example 8 shows that (I)
This is the case when there are many parts, and the workability is poor.

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

The thermoplastic resin composition of the present invention has excellent heat resistance, processability, chemical resistance, impact resistance, and mold release properties. The thermoplastic resin composition of the present invention is particularly excellent in mold releasability, so that it is useful as a molding material for large molded products requiring excellent releasability, molded products having complicated shapes, Trouble due to poor mold release when performing the molding process of the molded article by automatic unmanned operation is greatly improved, and its industrial significance is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic view of a mold used for evaluating mold releasability, (a) is a plan view, (b) is a side view,
(C) is a front view.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeki Furuyama 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-4-7345 (JP, A) JP-A Sho 63-135441 (JP, A) JP-A-5-163404 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 55/02 C08L 25/00-25/18 C08L 33 / 18-33/26 C08L 35/06

Claims (1)

(57) [Claims] (I) (a) N-substituted maleimide monomer 5
50 wt%, (b) an aromatic vinyl monomer 10 to 94 wt%, and (c) a vinyl cyanide monomer 1 to 40 wt%
[However, (a) + (b) + (c) = 100% by weight] 5% by weight or more of a maleimide-based copolymer obtained by copolymerizing
Less than 50 parts by weight, (II) to 95 parts by weight of a rubber-modified styrene thermoplastic resin
And more than 50 parts by weight and (III) an organic polysiloxane in an amount of more than 0.05 part by weight and 3.0 parts by weight or less based on 100 parts by weight of the total amount of the components (I) to (II). A thermoplastic resin composition comprising: