JPH09217013A - Thermoplastic resin composition - Google Patents

Abstract

(57) [PROBLEMS] To provide a thermoplastic resin composition which is excellent in antistatic property and mold antifouling property and has little influence on the resin contained therein. SOLUTION: (A) Thermoplastic resin 60 to 96.9% by weight, (B) Paraffin wax 0.1 to 10% by weight,
(C) 72 to 99 mol% of ethylene structural units, 0 to 10 mol% of ester structural units, 0 to 6 mol% of carboxylic acid structural units, and 1 to 12 mol% of amide structural units are linearly regular or irregular. With a weight average molecular weight of 1,
000-100,000 cation-modified copolymer 3-3
A thermoplastic resin composition comprising 0% by weight.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition having excellent antistatic properties and mold contamination prevention properties.

[0002]

2. Description of the Related Art Thermoplastic resins are widely used as materials for packaging materials, electric products, automobile parts and the like because of their excellent moldability. However, these thermoplastic resins generally have a large electric resistance and have a serious drawback that they are easily charged by friction and attract dust.

As a conventional method for obtaining a thermoplastic resin having a permanent antistatic property, there is, for example, a method of blending a cation-modified copolymer (JP-A-5-5066). The thermoplastic resin composition containing this cation-modified copolymer has excellent electrical properties and can impart permanent antistatic properties with a smaller amount added.

However, since the thermoplastic resin composition containing the cation-modified copolymer has a higher metal affinity than the thermoplastic resin composition containing no such components, there is a problem that the molding die is contaminated. there were.

For the purpose of preventing mold contamination of the resin composition, a polyolefin resin is disclosed in JP-A-4-4-2.
Japanese Patent No. 58647 discloses a method using an inorganic acid or an organic acid. Similarly, for the purpose of preventing mold contamination of a specific amount of a resin composition such as a styrene resin, JP-A-5-287161 discloses a method using an ester wax. Further, in order to improve rubber mold contamination, a method using a quinoline derivative in JP-A-55-108429, a method using a metal salt of a diamine or a phosphoric acid ester in JP-A-64-1745, Japanese Patent Application Laid-Open No. 7-124956 describes a method using a release agent and the like.

According to these methods, the effect of preventing mold contamination is certainly recognized, but it is still insufficient in practical use, and the method of applying a release agent is very complicated. Productivity fell. Further, the thermoplastic resin may be colored due to an additive added to improve mold contamination, which is not a satisfactory solution to mold contamination.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object thereof is to have excellent antistatic properties and mold antifouling properties, and to minimize the influence on the resin contained therein. The present invention provides a thermoplastic resin composition that can be retained.

[0008]

The thermoplastic resin composition according to claim 1 comprises: (A) thermoplastic resin 60 to 96.9% by weight (B) paraffin wax 0.1 to 10% by weight (C). The following structural units (I) to (IV) are linearly or regularly arranged in a linear manner and have a weight average molecular weight of 1,0.
00-100,000 cation-modified copolymer 3-30
A thermoplastic resin composition containing 100% by weight. 72 to 99 mol% of ethylene structural unit represented by formula (I) 0 to 10 mol% of ester structural unit represented by formula (II) 0 to 6 mol% of carboxylic acid structural unit represented by formula (III) Amide or ester structural unit 1 represented by (IV)
~ 12 mol%

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[Chemical 6]

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Embedded image (In the formulas (II) and (IV), R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents an alkylene group having 2 to 8 carbon atoms, and R ³ and R ⁴ are each independently. R ⁵ represents an alkyl group having 1 to 4 carbon atoms, R ⁵ represents an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an arylalkyl group or aryl group having 6 to 8 carbon atoms, and Y represents — NH- or -O- are shown, further and X ^- R
⁶ OSO ₃ ⁻ and / or R ⁷ SO ₃ ⁻ are shown, and R ⁶ and R ^{7 each} represent an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 6 to 18 carbon atoms, or an aryl group. )

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Component (A) As the thermoplastic resin (A) used in the present invention, polyolefin resin, polyvinyl chloride, polystyrene resin, A
BS resins, polyamide resins, polyester resins, polycarbonate resins, modified polyphenylene ethers, etc. can be exemplified, but of these, the use of polyolefin resins, polystyrene resins, ABS resins has the advantage that the present invention can be carried out more effectively. preferable.

Here, the polyolefin resin includes polyolefins, ethylene-vinyl ester copolymers, ethylene-acrylic ester copolymers and the like, and the use of these various polyolefins is the component (C) in the present invention. It is preferable because it has an excellent compatibility with.

More specifically, the above polyolefins are
High density polyethylene, medium density polyethylene, low density polyethylene, polypropylene (PP), polybutene, poly-4-methylpentene-1, a copolymer of ethylene and α-olefin, and the like. PP) is preferable, and the number average molecular weight thereof is usually 5,000 to 500,000, preferably 10,000 to 200,000.
00 is suitable.

Polystyrene as the polystyrene resin,
High-impact polystyrene (HIPS), (meth) acrylic acid ester-styrene copolymer, styrene-α-
Methylstyrene copolymer, of which high impact polystyrene (HIPS) is preferred and number average molecular weight is 1
Those of 10,000 to 200,000 are suitable.

The type of the ABS resin is not particularly limited, and those obtained by the grafting method or the polymer blending method can be used. Further, AS resin (acrylonitrile styrene resin), AES resin (acrylonitrile-EPDM-styrene resin) and the like can be used, but AB is preferable.
S resin.

The content of the thermoplastic resin (A) in the thermoplastic resin composition of the present invention must be in the range of 60-96.9% by weight, preferably 80-9.
It is 4.9% by weight. If it is less than 60% by weight, mechanical strength such as impact resistance is not sufficient, which is not preferable.

Component (B) The paraffin wax (B) in the thermoplastic resin composition of the present invention is an aliphatic hydrocarbon which is a crystalline paraffin separated from petroleum, and is mainly composed of regular paraffins, but isoparaffins and naphthenes. May be included. The number of carbon atoms is C _{16 to} C ₄₀ , and C ₂₀ to C ₄₀
The aliphatic hydrocarbon of ₃₅ is preferable in terms of the balance between the affinity for the resin and the effect of preventing mold contamination.

The amount of the paraffin wax (B) added to the thermoplastic resin composition of the present invention is required to be 0.1 to 10% by weight, preferably 0.5 to 5% by weight. If the addition amount is less than 0.1% by weight, it is not preferable because the prevention of mold contamination is hardly exhibited, while it is 10% by weight.
When it exceeds, the appearance of the molded product is deteriorated and the rigidity is lowered, which is not preferable.

Component (C) The constitution of the cation-modified copolymer (C) used in the present invention will be described in detail below. In the cation-modified copolymer used in the resin composition of the present invention, the ethylene structural unit represented by the formula (I) has 72 to 9 in the molecule.
9 mol% is contained, but this content ratio is 72 mol%
When it is less than, the relative ester structural unit (I
Since the content ratios of I) and the amide structural unit (IV) increase, the compatibility deteriorates when compounded with a thermoplastic resin, particularly a polyolefin, and as a result, the mechanical properties of the resin deteriorate. Further, when the content ratio of the ethylene structural unit (I) exceeds 99%, the antistatic ability of the cation-modified copolymer of the present invention becomes small. The content of the ethylene structural unit (I) is preferably 88 to 93 mol% from the viewpoint of the balance of softening point, mechanical properties and antistatic ability.

In the cation-modified copolymer of the present invention,
The ester structural unit represented by the formula (II) is contained in the molecule in an amount of 0 to 10 mol% as described above. When this content ratio exceeds 10 mol%, the crystallinity of the copolymer becomes low, and tackiness and stickiness occur, and the humidity dependence of the antistatic ability becomes large. Furthermore, when blended with polyolefin or the like, mechanical properties are deteriorated. The content of the ester structural unit (II) is preferably 0.5 to 6 mol% from the viewpoint of the softening point and the compatibility with the resin.

In the ester structural unit (II), R ¹ represents an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include methyl group, ethyl group, n-propyl group and iso-
Examples thereof include a propyl group and a tert-butyl group, and these groups may be mixed in one molecule. Of these, a methyl group and an ethyl group are more preferable from the viewpoint of maintaining the softening point of the obtained cation-modified copolymer.

In the cation-modified copolymer of the present invention,
Carboxylic acid structural unit (III) is 0 to 6 mol% in the molecule
It is contained. When it exceeds 6 mol%, the thermoplastic resin internally added thereto becomes hard. The content ratio of the carboxylic acid structural unit (III) is preferably 0.2 to 1.5 mol% from the viewpoint of antistatic property, impact resistance, bending resistance, and adhesiveness.

In the cation-modified copolymer of the present invention,
The amide or ester structural unit represented by the formula (IV) is contained in the molecule in an amount of 1 to 12 mol%, and when the content ratio is less than 1 mol%, the antistatic ability of the copolymer is reduced. Run out. On the other hand, if the content exceeds 12 mol%, hygroscopicity may occur when blended with the thermoplastic resin, or the mechanical properties of the resin may deteriorate due to deterioration of compatibility. From these tradeoffs, the content of the amide or ester structural unit (IV) is particularly preferably 1.2 to 10 mol%.

The amide or ester structural unit (I
In V), R ² represents an alkylene group having 2 to 8 carbon atoms, and specific examples thereof include an ethylene group, a propylene group, a hexamethylene group, and a neopentylene group. These groups are mixed in one molecule. Is also good. Among these groups, an ethylene group and a propylene group are more preferable, and a propylene group is particularly preferable, from the viewpoint of easy production and economical efficiency.

R ³ and R ⁴ in the amide or ester structural unit (IV) each independently represent an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group and a butyl group. However, these groups may be the same or different for each structural unit. Among these groups, a methyl group and an ethyl group are particularly preferable from the viewpoint of imparting antistatic properties.

R ⁵ in the amide or ester structural unit (IV) is an alkyl group having 1 to 18 carbon atoms, and 6 to 6 carbon atoms.
8 represents an arylalkyl group or an aryl group, and specific examples include a methyl group, an ethyl group, an n-propyl group, is
Examples thereof include o-propyl group and benzyl group, and these groups may be mixed in one molecule. Among these groups, a lower alkyl group is more preferable from the viewpoint of imparting antistatic ability, and a lower alkyl group or a benzyl group is more preferable from the viewpoint of heat resistance. Particularly preferred are methyl group and ethyl group.

Y in the amide or ester structural unit (IV) represents --NH-- or --O--, especially --NH--
Is more preferred.

The counterion X ⁻ of the quaternary ammonium salt in the amide or ester structural unit (IV) is R ⁶ OS.
O ₃ ⁻ and / or R ⁷ SO ₃ ⁻ , wherein R ⁶
And R ⁷ is an alkyl group having 1 to 12 carbon atoms, 6 to 6 carbon atoms.
18 represents an arylalkyl group or an aryl group. R
Specific examples of ⁶ and R ⁷ include a methyl group, an ethyl group, a propyl group, a phenyl group and a toluyl group, and these groups may be mixed in one molecule. From the viewpoint of heat resistance, a lower alkyl group, an aryl group and a toluyl group are more preferable.

Further, the structural unit (V) represented by the formula [Chemical Formula 9] may be contained within a range where there is no practical problem in terms of heat resistance. Here, R ² , R ³ , and R ⁴ are
The same as in the case of the amide or ester structural unit of formula (IV).

[0028]

Embedded image .

The weight average molecular weight of the cation-modified copolymer (C component) having the above-mentioned constitution is measured by gel permeation chromatography, and the weight average molecular weight in terms of polystyrene is used as an ultrahigh temperature GPC method (Kinukawa et al. Vol. 44, No. 2, pp. 139-141, 1987). The range of the weight average molecular weight is 1,000 to
100,000. When the weight average molecular weight is less than 1,000, the molecular weight is too small and the cation-modified copolymer of the present invention is volatilized by heat when blended in a thermoplastic resin and heated. The weight average molecular weight is 10
If it exceeds 50,000, the viscosity of the cation-modified copolymer of the present invention when melted will be too high and the workability will be deteriorated. The particularly preferable weight average molecular weight of the cation-modified copolymer of the present invention is in the range of 3,000 to 70,000.

The amount of the cation-modified copolymer (C) in the thermoplastic resin composition of the present invention is practically 3 to 30% by weight, but when the amount is less than 3% by weight. It is difficult to obtain the required antistatic property, and conversely, when the compounding amount exceeds 30% by weight, the mechanical properties of the resin, particularly the impact strength, deteriorates. From the viewpoint of the balance between the antistatic property and the mechanical properties of the resin, the amount of the cation-modified copolymer (C) is particularly preferably 5 to 20% by weight.

As the method for producing the thermoplastic resin composition in the present invention, the thermoplastic resin (A), the paraffin wax (B), and the cation-modified copolymer (C) are mixed in advance and the mixture is kneaded in a kneader, for example, Pelletized by a twin-screw extruder or the like.

[0032]

EXAMPLES In order to describe the present invention more specifically, the following examples and comparative examples will be described.

Synthesis example (cation-modified copolymer (a)-
(Synthesis of (k)) (see [Table 1]) 150 ml of xylene and ethylene / acrylic acid copolymer were placed in a 1-liter four-necked flask equipped with a thermometer, a stirrer, a dropping funnel, and a Dean-Stark water diverter. (Ethylene / acrylic acid = 91/9 (mol% / mol%)) and 150 g of p-toluenesulfonic acid were charged. Next, N, N-dimethylaminopropylamine 5
4 g was charged and reacted at 140 ° C. for 17 hours using an oil bath, and the amidation reaction was continued until the azeotropy of the produced water was not observed.

300 g of the obtained reaction product was cooled to 80 ° C., and 73 g of diethyl sulfuric acid was gradually added dropwise from the dropping funnel over 1 hour. During this time, fever was observed,
The reaction temperature was maintained at 90 ° C. by cooling, and after completion of dropping, an aging reaction was performed at 100 ° C. for 4 hours. The reaction product obtained here was poured into a large amount of methanol, and the produced precipitate was collected and dried to obtain a cation-modified copolymer (a).

Further, as in the above synthesis example, [Table 1]
The cation-modified copolymers (b) to (k) shown in Table 1 were obtained (the cation-modified copolymer (a) is also shown in [Table 1]).

[0036]

[Table 1] .

Examples 1 to 38 and Comparative Examples 1 to 27 Thermoplastic resins (A), paraffin wax (B) shown in [Table 2] to [Table 5], and cation-modified co- polymers obtained in the above synthesis examples. Combined (C) and other additives were mixed in the proportions shown in the same table, and this was used as S2 type KRC manufactured by Kurimoto Iron Works Co., Ltd.
What was kneaded with a kneader at 200 ° C. was pelletized.

After drying the obtained pellets, they were molded at 210 ° C. by an NN-Hyper Shot 3000 injection molding machine manufactured by Niigata Iron Works Co., Ltd., and 60 mm × 60 mm × 3 m.
A test piece composed of a flat plate of m was formed.

The components (A), (B) and other additives used in this example are listed below.

(Component A: thermoplastic resin) PP (polypropylene); Tokuyama Polypro ME-230,
Tokuyama Corp., number average molecular weight 35.000 HIPS (high impact polystyrene); Estyrene H-65, Nippon Steel Chemical Co., Ltd. ABS (ABS resin); JSR ABS35, Japan Synthetic Rubber Co., Ltd. B component: paraffin wax) No. 115; Paraffin wax (C ₂₄ ) No. manufactured by Nippon Seiro Co., Ltd. 135; the _(C 27) No. 155; the same ( _C33 ) (other additives) * 1; lauric acid * 2; 8-hydroxyquinoline

[Table 2]

[Table 3]

[Table 4]

[Table 5] .

Using this test piece, the mold contamination preventing property, the influence on the resin, and the antistatic property were examined.

(Mold Contamination Prevention Property and Effect on Resin) Regarding the mold contamination prevention property and the effect on the resin, the mold surface and the resin molded product surface were observed at 50 shots at the time of molding in the above method. Then, the degree of contamination was evaluated. The judgment criteria are as shown in [Table 6] below.

[0043]

[Table 6] .

(Antistatic property) The antistatic property was measured by measuring the surface specific resistance value of the test piece. That is, the test piece obtained by the above method is
Humidify for 12 hours at 65 ° C and 65% RH,
It was measured with a DVANTEST R8340 Ultra Resistance Meter at an applied voltage of 500V. The results are also shown in [Table 2] to [Table 5] above.

[0045]

EFFECT OF THE INVENTION The thermoplastic resin composition of the present invention is a resin composition comprising a specific amount of a thermoplastic resin and a cation-modified copolymer paraffin wax, and is excellent in permanent antistatic property as well as in preventing mold contamination. Are better. Also, it has little effect on the resin.

Claims (1)

[Claims] 1. A thermoplastic resin 60 to 96.9% by weight (B) Paraffin wax 0.1 to 10% by weight (C) The following structural units (I) to (IV) are linearly and regularly formed. Alternatively, the weight average molecular weight formed by irregular arrangement is 1,0.
00-100,000 cation-modified copolymer 3-30
A thermoplastic resin composition containing 100% by weight. 72 to 99 mol% of ethylene structural unit represented by formula (I) 0 to 10 mol% of ester structural unit represented by formula (II) 0 to 6 mol% of carboxylic acid structural unit represented by formula (III) Amide or ester structural unit 1 represented by (IV)
~ 12 mol% Embedded image Embedded image Embedded image (In the formulas (II) and (IV), R ¹ represents an alkyl group having 1 to 4 carbon atoms, R ² represents an alkylene group having 2 to 8 carbon atoms, and R ³ and R ⁴ are each independently. R ⁵ represents an alkyl group having 1 to 4 carbon atoms, R ⁵ represents an alkyl group having 1 to 18 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an arylalkyl group or aryl group having 6 to 8 carbon atoms, and Y represents — NH- or -O- are shown, further and X ^- R
⁶ OSO ₃ ⁻ and / or R ⁷ SO ₃ ⁻ are shown, and R ⁶ and R ^{7 each} represent an alkyl group having 1 to 12 carbon atoms, an arylalkyl group having 6 to 18 carbon atoms, or an aryl group. )