JP3132890B2 - ABS resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ABS (acrylonitrile-butadiene-styrene) resin composition having excellent permanent antistatic properties, which is used as a film, a bag or the like for a packaging material or a material for an automobile part.

[0002]

2. Description of the Related Art ABS
(Acrylonitrile butadiene styrene) resin
2. Description of the Related Art Conventionally, it has been widely used as a packaging material, a material for an automobile part, or the like as a film or a bag. However, these thermoplastic resins generally have a large drawback in that they have high electric resistance, are easily charged by friction, and attract dust and the like.

Therefore, in recent years, the following method has been proposed as a method for imparting an antistatic property to a thermoplastic resin.

That is, (a) a method in which an antistatic agent is applied to the resin surface and then dried, (b) a method in which an internally added antistatic agent is kneaded into the resin, and (c) a silicone compound is applied to the resin surface. And (d) a method of modifying the resin itself.

However, in the method (A), a surfactant solution is used as an antistatic agent, and such an antistatic agent is easily removed from the resin surface by washing, so that a permanent charging agent is used. The protective ability could not be provided.

In the above method (b), glycerin fatty acid ester,
Sorbitan fatty acid esters, alkyldiethanolamides, sodium alkylbenzenesulfonates, quaternary salts of alkylimidazoles and the like have been used. When these internal addition type antistatic agents are used, even if the antistatic agent on the resin surface is lost by washing, a new antistatic agent sequentially bleeds from the inside thereof, so that the antistatic ability lasts for a relatively long time. .

However, in the method using the internal addition type antistatic agent, it takes a long time to recover the antistatic ability after the resin surface is washed, and when the antistatic agent bleeds excessively, However, there is a problem that the resin surface becomes tacky and dust or the like easily adheres.
Furthermore, since these antistatic agents are of low molecular weight, they are volatilized by heat during molding at a high temperature.
There were problems such as an economic disadvantage that an unnecessary amount of the antistatic agent had to be added, and difficulty in adjusting the effective amount of the antistatic agent.

In order to solve the above-mentioned drawbacks of the internally added antistatic agent, recently, polymethyl methacrylate in which 20 to 80 mol% of methoxy groups are modified with diethanolamine (JP-A-1-170603), alkoxypolyethylene A graft copolymer of glycol methacrylate (Japanese Patent Publication No. 58-39860), a styrene-maleic anhydride copolymer which has been imide-modified and then quaternized and cationized (Japanese Patent Publication No. 29820/1989);
Comb-type copolymer of high-molecular-weight monomer in which terminal carboxyl group is converted to methacryloyl group with glycidyl methacrylate from polymethyl methacrylate having a carboxyl group and aminoalkyl acrylate or acrylamide, and a quaternized cation-modified product thereof (JP-A-62-1
Polymer compounds having an antistatic functional group, such as No. 21717, have been proposed as internally added antistatic agents.

However, even when any of the above polymer compounds is used as an internally added antistatic agent, the physical properties of the resin such as transparency and high elongation are reduced, and the antistatic ability of the resin and its durability are also reduced. Was insufficient.

Further, in the method (c), the antistatic ability is maintained semipermanently, but the silicone compound used is expensive and the working efficiency is poor, so that it is very disadvantageous in terms of cost.

In the method (d), a hydrophilic group is introduced into the resin. However, it is necessary to introduce a considerable amount of a hydrophilic group in order to impart a sufficient antistatic ability. However, when a hydrophilic group is introduced as described above, there is a possibility that the moisture absorption resistance of the resin itself and the mechanical properties are reduced.

As described above, the conventional antistatic property A
The BS resin composition was still insufficient in antistatic ability, durability, physical properties of the resin, and the like.

In the method of kneading or applying the antistatic agent, the antistatic effect is exhibited by the antistatic agent layer which bleeds out or adheres to the resin surface.
If the antistatic agent layer falls off due to friction, washing or the like, there is a problem that the antistatic effect is lost. In particular, in a system in which an alkyldiethanolamine or the like generally used in an ABS resin is kneaded, the friction resistance and water resistance of the resin are significantly reduced.

Furthermore, in the method of kneading the antistatic agent,
The antistatic agent often bleeds out excessively, causing problems such as stickiness and dusting on the resin surface, and deterioration of the resin surface condition such as deterioration of the printing characteristics of the resin surface.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide an ABS resin composition having excellent permanent antistatic properties and good physical properties of the resin itself. Is to do.

[0016]

Means for Solving the Problems To achieve the above object, the resin composition of the present invention comprises an ABS (acrylonitrile-butadiene-styrene) resin as a matrix resin, and the following cationic copolymer as a matrix resin. ~ 30% by weight
It is a resin composition obtained by addition.

The cationic copolymer has an ethylene structural unit (I) 65 to 99 represented by the general formula 4 in the molecule.
It is a linear copolymer having a molar average molecular weight of 1,000 to 50,000 and containing 1 to 35 mol% of the acrylamide structural unit (III) represented by the general formula (5). Each structural unit may be arranged regularly or irregularly.

[0018]

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[0019]

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The cationic copolymer has an ethylene structural unit (I) 65 represented by the general formula 4 in the molecule.
-99 mol%, 15 mol% or less of the acrylate structural unit (II) represented by the general formula 6, and 1-35 mol% of the acrylamide structural unit (III) represented by the general formula 5; It is a linear copolymer having a weight average molecular weight of 1,000 to 50,000. Each structural unit may be arranged regularly or irregularly.

[0021]

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The constitution of the cationic copolymer used in the resin composition of the present invention will be described in more detail below.

In the cationic copolymer used in the resin composition of the present invention, the ethylene structural unit (I) represented by the general formula (4) is contained in the molecule in an amount of 65 to 99 mol%. If the proportion is less than 65 mol%, the compatibility with the matrix resin is deteriorated, and the physical properties of the resin composition are significantly reduced. On the other hand, if the content exceeds 99 mol%, sufficient antistatic ability cannot be obtained. From the viewpoints of compatibility and antistatic ability, the content of the ethylene structural unit (I) is preferably from 80 to 97 mol%.

Further, in the cationic copolymer used in the resin composition of the present invention, the acrylate structural unit (II) represented by the general formula (6) contains 0 to 15 mol% in the molecule.
It is contained. When the acrylate structural unit (II) is contained, the compatibility between the cationic copolymer and the matrix resin is improved. Acrylate structural unit (I
When the content of (I) exceeds 15 mol%, the physical properties of the resin composition deteriorate, and the content of the acrylate structural unit (II) is preferably about 3 to 13 mol% from the viewpoint of compatibility.

In the general formula 6 of the acrylate structural unit (II), R ¹ represents a methyl group or an ethyl group;
R ¹ may be the same or different for each structural unit (that is, a methyl group and an ethyl group may be mixed in one molecule).

Further, in the cationic copolymer used in the resin composition of the present invention, the acrylamide structural unit (III) represented by the general formula (5) is a cationic acrylamide structural unit in the form of a quaternary ammonium salt. And contained 1 to 35 mol% in the molecule. When the content is less than 1 mol%, the resin composition lacks antistatic ability, and when the content exceeds 35 mol%, the compatibility of the cationic copolymer with the matrix resin is deteriorated. From the viewpoints of antistatic ability and compatibility, the content of the acrylamide structural unit (III) is preferably 3 to 15 mol%.

In the general formula (5) of the acrylamide structural unit (III), R ² represents an ethylene group or a propylene group, which may be mixed in one molecule, and R ³ and R ⁴ are Represents a methyl group, and R ⁵ represents a methyl group or a methyl group from the viewpoint of easiness of production and good antistatic ability.
It represents a lower linear alkyl group such as an ethyl group or an arylalkyl group such as a benzyl group. Further, X ^- is, Cl ^-,
Br ^-, I ^-, etc. halide ion, CH ₃ OSO ₃
^- or CH ₃ CH ₂ OSO ₃ ^- represents a.

The weight average molecular weight of the above-mentioned cationic copolymer is measured by gel permeation chromatography. The weight average molecular weight in terms of polystyrene is determined by an ultra-high temperature GPC method (Kinukawa, “Polymer Transactions, Vol. 44, No. 2”). ", 13
9 to 141, 1987), but the weight average molecular weight ranges from 1,000 to 50,000. When the weight-average molecular weight is less than 1,000, the cationic copolymer becomes waxy, handling property deteriorates, and furthermore, excessive bleed-out causes a problem that the tackiness of the resin surface is increased, and the weight-average molecular weight is increased. Is 5
When it exceeds 000, there arises a problem that the compatibility with the matrix resin is deteriorated. The preferred weight average molecular weight of the cationic copolymer is from 3,000 to 30,00.
0.

As a method for producing the cationic copolymer used in the resin composition of the present invention, for example, an ethylene-acrylate copolymer obtained by copolymerizing ethylene and an acrylate by a high-pressure polymerization method is used. JP-A-60-79008 discloses that the ethylene-acrylic acid ester-acrylic acid copolymer is thermally degraded simultaneously with hydrolysis to a desired molecular weight by the method described in JP-A-60-79008. Amidation with an aminoalkylamine, cation modification with a known quaternizing agent and isolation to obtain the above cationic copolymer.

In the resin composition of the present invention, the addition amount of the above-mentioned cationic copolymer to the matrix resin is practically 3 to 30% by weight, but if this addition amount is less than 3% by weight, The required antistatic properties cannot be obtained,
Conversely, if the amount exceeds 30% by weight, the mechanical properties of the resin, particularly the impact strength, will be reduced. From the balance between the antistatic property and the mechanical properties of the resin, the amount of the cationic copolymer to be added to the matrix resin is particularly preferably 5 to 20% by weight.

In the resin composition of the present invention, an ABS resin is used as a matrix resin, but the type is not particularly limited. Specific examples of the ABS resin include a physical mixture (blend) of butadiene-acrylonitrile rubber and styrene-acrylonitrile resin, a graft polymer of acrylonitrile and styrene on butadiene rubber or butadiene-styrene rubber, and a copolymer of acrylonitrile, butadiene and styrene. There are homogeneous terpolymers and the like.

The method for producing the resin composition of the present invention includes:
The cationic copolymer may be added to the ABS resin in a known amount by a known method, for example, by a twin-screw extruder.

[0033]

The internal addition type antistatic agent bleeds out to the surface of the resin to form a moisture-absorbing layer and leaks the generated static electricity, whereas the cationic anti-static agent added in the resin composition of the present invention is used. The polymer forms a continuous layer in the matrix resin, and the leakage of static electricity occurs due to the movement of the charge accompanying the movement of the counter ion of the cationic group in the copolymer molecule. Accordingly, the cationic copolymer in the present invention has a higher rate of static electricity leakage than the conventional internally added antistatic agent.

Further, in the resin composition of the present invention, since the cationic copolymer is not present at a high concentration near the surface of the resin which is easily affected by external factors, the antistatic effect due to friction on the resin surface, washing with water and the like is eliminated. No loss occurs.

[0035]

The resin composition of the present invention has a number of remarkable functions and effects as described below since the cationic copolymer is not present at a high concentration near the surface of the resin.

(1) The resin composition of the present invention is a resin composition which does not lose the antistatic effect due to friction on the resin surface, washing with water, etc., and has excellent friction resistance and water resistance. Further, even under severe conditions (such as molding at a high temperature) under which the effect is deactivated when a normal antistatic agent is used, the resin composition of the present invention can be used at a high level. Retains antistatic ability.

(2) In the resin composition of the present invention, as in the case of using a conventional internal addition type antistatic agent, excessive bleed-out causes the resin surface to become tacky, and dust and the like are more likely to adhere. Problem does not occur.

(3) In the resin composition of the present invention, as in the conventional antistatic resin composition, the resin has impact resistance, strong elongation,
There is no reduction in physical properties such as transparency.

[0039]

EXAMPLES Specific examples A to C of synthesizing the cationic copolymer used in the resin composition of the present invention will be described below.

Specific Example of Synthesis of Cationic Copolymer A 400 ml of xylene, ethylene / ethyl acrylate were placed in a 1-liter four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a Dean-Stark separator. 150 g of an acrylic acid copolymer (ethylene / ethyl acrylate / acrylic acid = 93/3/4) and 1.0 g of paratoluenesulfonic acid were charged.

Next, 21.1 g of N, N-dimethylaminopropylamine was charged and the mixture was heated at 140 ° C. using an oil bath.
The water generated by heating was continuously removed by azeotropy with xylene, and further reacted at 140 ° C. for 17 hours, and the amidation reaction was continued until the azeotrope of generated water was not observed.

458 g of the obtained reaction product was cooled to 80 ° C., and 31.1 g of diethyl sulfate was added thereto from a dropping funnel.
It was dropped slowly over time. During this period, heat generation was observed, but the reaction temperature was maintained at 90 ° C. by cooling, and after completion of the dropwise addition, an aging reaction was performed at 100 ° C. for 4 hours.

The reaction product obtained here was put into a large amount of methanol, and the formed precipitate was recovered and dried to obtain a cationic polymer A.

The weight average molecular weight of polymer A was 5,300.

Specific Synthesis Example B of Cationic Copolymer 400 ml of xylene, ethylene-acrylic acid copolymer were placed in a 1-liter four-necked flask equipped with a thermometer, stirrer, dropping funnel and Dean-Stark separator. 150 g of a polymer (ethylene / acrylic acid = 91/9) and 1.0 g of paratoluenesulfonic acid were charged.

Next, 38.5 g of N, N-dimethylaminoethylamine was charged, and water produced by heating to 140 ° C. using an oil bath was continuously removed by azeotropy with xylene. For 17 hours, and the amidation reaction was continued until azeotropic formation of generated water was not observed.

The obtained reaction product was cooled to 80 ° C., and 72.0 g of methyl iodide was added dropwise thereto over 1 hour. During this period, heat generation was observed, but the reaction temperature was maintained at 90 ° C. by cooling, and after completion of the dropwise addition, an aging reaction was performed at 100 ° C. for 4 hours.

The obtained reaction product was poured into a large amount of n-hexane, and the formed precipitate was recovered and dried to obtain a cationic polymer B.

The weight-average molecular weight of Polymer B was 6,000.

Specific Example of Synthesis of Cationic Copolymer C 400 ml of xylene, ethylene / ethyl acrylate were placed in a 1 liter four-necked flask equipped with a thermometer, a stirrer, a dropping funnel and a Dean-Stark separator. 150 g of an acrylic acid copolymer (ethylene / ethyl acrylate / acrylic acid = 93/3/4) and 1.0 g of paratoluenesulfonic acid were charged.

Next, 21.1 g of N, N-dimethylaminopropylamine was charged and the mixture was heated at 140 ° C. using an oil bath.
The water generated by heating was continuously removed by azeotropy with xylene, and further reacted at 140 ° C. for 17 hours, and the amidation reaction was continued until the azeotrope of generated water was not observed.

458 g of the obtained reaction product was cooled to 80 ° C., and 25.5 g of benzyl chloride was added thereto from a dropping funnel.
It was dropped slowly over time. During this period, heat generation was observed, but the reaction temperature was maintained at 90 ° C. by cooling, and after completion of the dropwise addition, 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 formed precipitate was recovered and dried to obtain a cationic polymer C.

The weight average molecular weight of Polymer C was measured and found to be 5,500.

Hereinafter, specific examples of the resin composition of the present invention and specific comparative examples for comparison and comparison will be described. Various physical properties of the obtained resin composition were measured by the following methods. did.

Method of Evaluating Various Physical Properties of Resin Composition Surface resistivity was measured by applying a voltage of 500 V to a test piece of the resin composition using a megaohmmeter (manufactured by Toa Denpa Co., Ltd.).

Charged voltage decay rate Using a static honest meter (manufactured by Shishido Shosha),
The time required for applying a voltage of 10,000 V for 30 seconds to a test piece of the resin composition and reducing the voltage to half of the initial voltage was shown in seconds.

Abrasion Resistance A test piece of the resin composition was rubbed 80 times with gauze soaked in water and then dried, and the surface resistivity of the test piece was measured in the same manner as described above.

Water Resistance A test piece of the resin composition was boiled in boiling water for 2 hours, dried, and the surface resistivity of the test piece was measured in the same manner as described above.

Izod Impact Strength The Izod impact strength of a test piece of a resin composition was measured according to JIS K
Measured according to -7110.

Incidentally, regarding the above electrical characteristics,
It is measured after adjusting the humidity at a temperature of 20 ° C. and a relative humidity of 60% for 24 hours or more.

About ABS resin composition: Examples 1 to 8 The cationic polymer obtained in the above-mentioned synthesis example was applied to ABS resin (Psycolac T, manufactured by Ube Sykon Co., Ltd.) using a twin-screw extruder equipped with a quantitative supply device. A or B is added in a specified amount,
Pelletized.

The pellets were molded by an injection molding machine into test pieces, and various physical properties were measured. The results are shown in Table 1.

Comparative Examples 1 and 2 Test pieces of the resin composition were prepared in the same manner as in Examples 1 to 8 using lauryl diethanolamine instead of the cationic polymer, and various physical properties were measured. It was shown to.

Comparative Examples 3 to 6 The cationic polymers A or B were added to ABS resin (Psycholac T, manufactured by Ube Saikon Co., Ltd.) in an amount of 1.0% by weight or 40.0% by weight. A test piece of the resin composition was prepared in the same manner as described above. Various physical properties of each test piece were measured, and the results are shown in Table 1.

Examples 9 to 12 In Examples 1 to 8, test pieces of a resin composition were prepared using the polymer C obtained in the above Synthesis Example as a cationic polymer, and various physical properties were measured. The results are shown in Table 1.

[0067]

[Table 1]

According to Table 1, when the cationic polymer A, B or C is added to the resin in the range of 5.0 to 30.0% by weight, the antistatic property, the friction resistance, the water resistance and the impact resistance are excellent. An ABS resin composition was obtained.

When lauryl diethanolamine was added to the resin in place of the cationic polymers A, B and C, the surface resistivity of the resin was almost the same, but the friction resistance and water resistance were greatly reduced.

Further, the amount of the cationic polymer to be added was 1.
In the case of 0% by weight, the charged voltage decay rate was greatly reduced and the surface specific resistance was large.

When the addition amount of the cationic polymer was 40.0% by weight, the antistatic property of the resin was good, but the Izod impact strength was greatly reduced. In addition, when a test for water resistance was performed, the resin was sometimes deformed.

Continuation of the front page (56) References JP-A-5-194760 (JP, A) JP-A-2-229862 (JP, A) JP-A-63-54467 (JP, A) JP-A-63-54466 (JP) JP-A-54-66386 (JP, A) JP-A-62-121717 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 55/02 C08L 23/08

Claims (3)

(57) [Claims] In the molecule, 65 to 99 mol% of an ethylene structural unit (I) represented by the general formula 1 and an acrylamide structural unit (III) 1 represented by the general formula 2
~ 35 mol% and a weight average molecular weight of 1,000
An ABS obtained by adding a linear cationic copolymer having a molecular weight of up to 50,000 to an ABS resin.
Resin composition. Embedded image Embedded image (Where R ² represents an ethylene group or a propylene group, R ³ and R ⁴ represent a methyl group, and R ⁵ represents a lower linear alkyl group such as a methyl group or an ethyl group or a benzyl group. And X ^- is a halide ion, CH ₃ OSO ₃ ^- or CH ₃ CH
₂ OSO ₃ ^- represents a. Note that R ² may be the same or different for each structural unit. ) 2. An ethylene structural unit (I) 65 to 9 represented by the general formula 1 in a molecule.
9 mol% and an acrylate structural unit (II) 15 represented by the general formula 3
Mol% or less, and acrylamide structural unit (III) 1 represented by the general formula 2
~ 35 mol% and a weight average molecular weight of 1,000
ABS obtained by adding a linear cationic copolymer of up to 50,000 to an ABS resin
Resin composition. Embedded image (However, in the chemical formula 3, R ¹ represents a methyl group or an ethyl group, and R ¹ may be the same or different for each structural unit.) 3. The ABS resin composition according to claim 1, which is obtained by adding 3 to 30% by weight of the cationic copolymer to the ABS resin.