JPH09272721A - Copolymer and composition thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolymer which can be compounded with a wide variety of resins, can retain satisfactory antistatic performance over long, and has excellent thermal stability. SOLUTION: This copolymer is one made up mainly of units (A) derived from a compound having a sulfo group and an ethylenic bond, units (B) represented by the formula, and units (C) derived from a compound having an ethylenic bond and different from the units (A) and (B), or a salt thereof. The content of the units (A) is 5-30wt.%, that of the units (B) is 10-70wt.%, and that of the sum of the units (A) and (B) is 20-90wt.%. In the formula, R<1> is hydrogen or methyl, R<2> is an optionally hydroxylated divalent hydrocarbon group, R<3> is a 2-4C divalent saturated aliphatic hydrocarbon group, R<4> is a 4-30C monovalent hydrocarbon group, and n is a number of 3-200 on the average.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a copolymer, an antistatic agent using the same, and a composition thereof.

[0002]

2. Description of the Related Art Although plastics are widely used for covers and housings of home electric appliances, they have excellent insulating properties, but on the other hand, they are prone to electrification, dust adhesion, and adverse effects on semiconductor products. . Therefore, conventionally, as a method of suppressing charging, a surfactant type antistatic agent represented by a higher fatty acid derivative or the like has been generally added. The antistatic agent exerts its performance by being present near the surface of the molded product, but on the other hand, it prevents the contamination of the molding die, the generation of dirt on the product surface over time, and the migration to the surface due to long-term use. There is a problem such as a decrease in antistatic performance due to the dropping of the agent.

As a method for improving these, a poly (meth) acrylic acid polyalkylene oxide ester type reactive antistatic agent is copolymerized with a radical polymerizable monomer typified by styrene, methyl methacrylate, etc.
A method of obtaining a non-extraction type antistatic resin and adding this to a plastic (Japanese Patent Publication No. 57-24364, Japanese Patent Publication No. 2)
-38110). However, the antistatic resin composition produced by such a method has a decrease in elastic modulus because the polyalkylene oxide portion acts as a plasticizer,
There are problems such as deterioration of thermal stability. Polyamide elastomers and polyester elastomers may also be added to plastics as antistatic resins, but the thermal stability of the resin composition decreases due to the amide bond and ester bond that make up the main chain. Occurs. Since the acrylic resin has a higher molding temperature than other general-purpose resins, the antistatic resin compounded therein has particularly severe requirements for thermal stability in order to prevent gelation, decomposition, coloring, and the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is that it can be blended with a wide range of resins including acrylic resins, and can retain good antistatic performance for a long period of time, and has good thermal stability. An object of the present invention is to provide an excellent polymer, an antistatic agent comprising the same, and a resin composition containing the same.

[0005]

As a result of the study by the present inventors, a compound having a sulfonic acid group and an ethylenically unsaturated bond, a polyalkylene oxide chain in which one end of the molecular chain is terminated by a hydrocarbon group And a specific compound having an ethylenically unsaturated bond, and a copolymer of a compound having an ethylenically unsaturated bond other than these, or a salt thereof was found to sometimes solve the above problems, and further studies were conducted. As a result, the present invention has been completed.

That is, according to the present invention, a unit (A) derived mainly from a compound having a sulfonic acid group and an ethylenically unsaturated bond, and a unit (B) represented by the formula (1).
And a unit (C) derived from a compound having an ethylenically unsaturated bond and different from (A) and (B), the weight percentage of (A) is 5 to 30%, and (B)
And a salt thereof, wherein the weight percentage of (A) is 10 to 70%, and the sum of the weight percentage of (A) and the weight percentage of (B) is 20 to 90%.

[0007]

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(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group which may have a hydroxyl group, and R ³ represents a divalent hydrocarbon group having 2 to 4 carbon atoms. It represents a saturated aliphatic hydrocarbon group, R ⁴ represents a monovalent hydrocarbon group having 4 to 30 carbon atoms, and n represents a number of 3 to 200 in average value.)

According to the present invention, there is provided an antistatic agent comprising the above copolymer or a salt thereof. Further, according to the present invention, there is provided a resin composition containing 100 parts by weight of a thermoplastic resin and 1 to 80 parts by weight of the above copolymer or a salt thereof. Hereinafter, the present invention will be described in detail. The "copolymer or salt thereof" of the present invention may be simply referred to as "copolymer".

In the present invention, the structural unit (A) or a vinyl compound having a sulfonic acid group and an ethylenically unsaturated bond or a salt thereof which gives a structural unit in the form of a salt of the structural unit is represented by the formula (2). Those having the structure shown are preferred. Examples thereof include salts of allyl sulfonic acid, methallyl sulfonic acid, p-styrene sulfonic acid, p-vinyl benzyl sulfonic acid and the like with alkali metals such as sodium and potassium, and quaternary ammonium. , And salts with organic cation compounds represented by quaternary phosphonium and the like are preferable.

[0011]

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(R ⁵ represents a hydrogen atom or a methyl group, and R 5
⁶ represents a divalent hydrocarbon group, M represents an m-valent cation, and m represents the ionic valence number of the cation M. )

The polyalkylene oxide compound which gives the structural unit (B) has a structure represented by the formula (3). The compound is a polymerizable double bond segment (a) of formula (4)
And a polyalkylene oxide segment (b) of formula (5)
And a hydrocarbon group segment (c) of the formula (6).

[0014]

[Chemical 6]

[0015]

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[0016]

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[0017]

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(In the above formulas, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group which may have a hydroxyl group, and R ³ represents 2 having 2 to 4 carbon atoms. Represents a valent saturated aliphatic hydrocarbon group, R ⁴ represents a monovalent hydrocarbon group having 4 to 30 carbon atoms, and n represents an average value of 3 to 200.)

R ² in the above formula (4) representing the polymerizable double bond segment (a) is a divalent hydrocarbon group which may have a hydroxyl group, and is a divalent hydrocarbon group having 1 to 4 carbon atoms. It is preferable that the hydrocarbon group is

Polyalkylene oxide segment (b)
Examples thereof include a polyethylene glycol chain and a polypropylene glycol chain, but a polyethylene glycol chain is preferable. Here, n representing the number of repeating alkylene oxide units is from 3 to 200 on average. When the number of repetitions is smaller than the above range, sufficient domain formation is not achieved to exhibit antistatic performance, and when it is larger than this range, sufficient antistatic performance is not exhibited due to crystallization and the like. From the viewpoint that the antistatic performance is exhibited particularly effectively, n is 1 in the average value.
It is preferably a number from 0 to 150. The n R ^{3 s} contained in the segment (b) may all be the same hydrocarbon group or may be two or more kinds of hydrocarbon groups.

The hydrocarbon group segment (c) has 4 carbon atoms.
To 30 hydrocarbon groups, and represents a linear or branched alkyl group or an aromatic group having an aliphatic group.
Examples are dodecyl group, tetradecyl group, stearyl group, nonylphenyl group and the like. When the number of carbon atoms is smaller than 4, sufficient antistatic performance is not exhibited. Also, when the carbon number is more than 30, the antistatic performance is insufficient,
In some cases, the mechanical performance may further deteriorate.

The polyalkylene oxide compound represented by the above formula (3), in which one end of the molecular chain is terminated by a hydrocarbon group, can be produced by a known method. For example, ethylene oxide or the like is polymerized using an alkali metal alkoxide of alkyl alcohol as a polymerization initiator, and then unsaturated carboxylic acid halides such as methacrylic acid chloride and acrylic acid chloride, and unsaturated carboxylic acid glycidyl esters such as glycidyl methacrylate and glycidyl acrylate. Examples thereof include a method of introducing an ethylenically unsaturated bond at the terminal of the molecular chain by reacting with an ester.

The compound having an ethylenically unsaturated bond which gives the structural unit (C) is, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-acrylic acid acrylate.
Acrylic acid derivatives typified by ethylhexyl; methyl methacrylate, ethyl methacrylate, methacrylic acid n
-Methacrylic acid derivatives such as butyl and lauryl methacrylate; vinyl ester compounds such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and α-methylstyrene. These are used alone or in combination of two or more. it can. When the copolymer of the present invention is used as a composition with another resin, the structural unit (C) is
It is preferable that it has an affinity for the other resin. For example, for the purpose of blending the copolymer with the acrylic resin, the structural unit (C) is preferably a unit derived from an acrylic acid derivative or a methacrylic acid derivative.

The weight percentage of each unit of (A), (B) and (C) with respect to the whole copolymer is such that (A) is 5 to 30%,
(B) is 10 to 70%, and the total of (A) and (B) is 20 to 90%. When the sum of the weight percentages of (A) and (B) is less than 20%, the ratio of the antistatic component becomes small, so that sufficient antistatic performance cannot be exhibited.
Further, when the content is more than 90%, the hydrophilicity becomes too high, so that the copolymer is likely to drop off from the resin composition containing the copolymer by washing with water and the durability of the desired antistatic performance is lowered. To do.

If the weight percentage of (A) is less than 5%, the antistatic performance of the intended copolymer of the present invention or the resin composition to which it is added deteriorates, and depending on the case,
Furthermore, the mechanical strength is also reduced. On the other hand, if it is more than 30%, the thermoplasticity of the copolymer or the resin composition to which it is added is significantly impaired, problems occur during blending, shaping, etc., and the antistatic performance is also reduced.

If the weight percentage of (B) is less than 10%, the antistatic performance of the copolymer or the resin composition to which it is added will not be exhibited. The mechanical strength of the resin composition containing the polymer is significantly reduced.

The copolymer of the present invention can be produced according to a general polymerization technique for copolymerizing a compound having an ethylenically unsaturated bond. For example, in solution polymerization, in a mixed solvent of an organic solvent such as dioxane or dimethylformamide and water, an azo compound such as N, N'-azobisisobutyronitrile, a peroxide such as benzoyl peroxide, or potassium persulfate. And the like using a general radical polymerization initiator such as persulfate. The temperature at that time may appropriately adopt a temperature suitable for the polymerization initiator to be used,
Generally, it is in the range of 0 to 100 ° C. In addition, a chain transfer agent such as an alkyl thiol can be used during the polymerization.

The thus obtained copolymer of the present invention can be used alone as an antistatic resin, but it can also be added to a resin to which antistatic performance is desired. The amount of addition at that time is arbitrary, and is determined, for example, from the balance of antistatic performance, mechanical properties, cost and the like. For example, the addition amount of 1 to 80 parts by weight is common to 100 parts by weight of the resin to which antistatic performance is desired to be added.

Since the copolymer of the present invention is excellent in heat resistance, a resin composition prepared by blending with a thermoplastic resin which is subjected to thermal molding and processing, among other resins, is particularly advantageous. It is effectively used. Examples of the thermoplastic resin used in the resin composition include acrylic resins; styrene resins; ABS resins; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyamide resins such as nylon-6; polycarbonate resins and the like. The composition of each of the units (A), (B) and (C) of the copolymer to be added can be appropriately set to a suitable value depending on the resin to be combined, and accordingly, the antistatic performance and mechanical properties can be improved. It is possible to balance the thermal properties.

Any known method may be used as a blending method for producing a resin composition containing the copolymer of the present invention and a thermoplastic resin. For example, blending can be performed by a melt-kneading method using a screw-type continuous extruder, a hot roll, or a kneader. The temperature at the time of blending is also possible within a normal range, for example, 150 to 3
00 ° C is preferred.

A molding / processing method is optional when the copolymer of the present invention or a resin composition containing the same and a thermoplastic resin is used as a molded product. As the method, a molding / processing method such as injection molding, extrusion molding, blow molding, and inflation molding, which are usually performed, can be applied.
In particular, when used as a resin composition, a molding method and a molding condition in which a strong shearing force is applied to the resin composition are adopted so that the antistatic component composed of the copolymer of the present invention can easily form a streak-shaped conductive circuit. Is preferred.

Regarding the molding temperature, the same temperature range as in the usual case can be adopted. For example, the molding can be carried out under the same conditions as the temperature range at the time of blending.

[0033]

EXAMPLES Specific examples of the present invention are shown below, but the scope of the present invention is not limited by these examples. In addition, each measured value was measured as follows.

(1) Nuclear magnetic resonance spectrum: The copolymer was dissolved in d ₆ -dimethylformamide to prepare a JN
A nuclear magnetic resonance spectrum of a hydrogen nucleus was measured by MLA-400. (2) Flexural modulus: A test piece was prepared in accordance with ASTM D-790 and its physical properties were measured. (3) Antistatic performance: A plate-shaped test piece having a thickness of 1 mm was prepared, and allowed to stand at 25 ° C. and 50% RH for 1 week.
Was applied to measure the maximum charge voltage and the half-life of charge decay. Furthermore, after the surface of the test piece was washed with distilled water, the same measurement was performed again. (4) Thermal stability: The sample was crushed and 270 ° C under a nitrogen stream.
It was filled in the heating cylinder of Capirograph 1C manufactured by Toyo Seiki Co., Ltd. This was held for 60 minutes and then extruded with a piston to visually evaluate the degree of coloring of the sample.

Reference Example 1 (Polyethylene oxide compound in which one end of the molecular chain is terminated by an alkyl group (3
-1) Production) In a glass reaction vessel equipped with a stirrer and a reflux condenser, degassed and dry toluene 90g were added to 20 g of dried lauryl alcohol and dissolved, and metallic sodium was added thereto to form sodium alkoxide. Converted The supernatant of the obtained solution was transferred to a pressure resistant reaction vessel equipped with a stirrer and a dropping funnel, and 120 g of dried ethylene oxide was introduced and polymerization was carried out. When the polymerization was completed, 14.4 g of methacrylic chloride was added from a dropping funnel to terminate the reaction. The obtained solution was treated with 1N-hydrochloric acid, the lower aqueous layer was removed, and the organic layer was dried over sodium sulfate overnight. Then, it is concentrated and dried in a vacuum, and the polyethylene oxide compound (3-
1) was obtained. According to ¹ H-NMR, the addition amount of ethylene oxide was 28.6 mol and the addition amount of the alkyl group having 12 carbon atoms was 1.1 mol per mol of the methacryloyl group.

Reference Example 2 (Polyethylene oxide compound (3 having one end of the molecular chain terminated with an alkyl group)
-2) Production) In a glass reaction vessel equipped with a stirrer and a reflux condenser, deaeration was performed on 28.5 g of dried stearyl alcohol,
100 g of dried toluene was added and dissolved, and metallic sodium was added thereto to convert into sodium alkoxide. The obtained solution was transferred to a pressure resistant reaction vessel equipped with a stirrer and a dropping funnel, 200 g of dried ethylene oxide was introduced, and polymerization was performed. When the polymerization was completed, 14.4 g of methacrylic chloride was added from a dropping funnel to terminate the reaction. After treating the resulting solution with 1N hydrochloric acid,
The lower aqueous layer was removed, and the organic layer was dried over sodium sulfate overnight. Then, the mixture is concentrated and dried in a vacuum, and a polyethylene oxide compound (3 having one end of the molecular chain stopped by a methacryloyl group and the other end stopped by a stearyl group (3
-2) was obtained. According to ¹ H-NMR, the addition amount of ethylene oxide per 1 mol of methacryloyl group is 20.2.
The amount of addition of the alkyl group having 18 carbon atoms was 1.0 mol.

Example 1 The inside of a glass reaction vessel equipped with a stirrer and a reflux condenser was replaced with nitrogen, and after degassing under reduced pressure, 1,4-dioxane (500 g) which had been subjected to a nitrogen gas blowing treatment, and distillation were carried out. Water 5
00g was charged. Then, treated with an aqueous solution of sodium hydroxide, washed with water and distilled to obtain methyl methacrylate 20.
g, p-sodium styrenesulfonate (Tosoh Corporation)
20 g of Spinomer NaSS) and 60 g of polyethylene oxide compound (3-1) were charged and stirred with stirring 8
The temperature was raised to 0 ° C. Then, 0.2 g of N, N'-azobisisobutyronitrile was charged and polymerization was carried out for 8 hours. After completion of the polymerization, the solution was taken out, dropped into a mixed solvent of acetone / n-hexane (80/20: volume ratio) to cause precipitation, and dried to obtain 88 g of a polymer (1-1). NMR
The compositional ratio calculated from is 31.
0% by weight, sodium p-styrenesulfonate unit 9.
It was 4% by weight.

Example 2 Monomer charge was 30 g of methyl methacrylate, p-
Polymerization was performed in the same manner as in Example 1 except that sodium styrenesulfonate (10 g) and polyethylene oxide compound (3-1) (60 g) were used. It was recovered and dried in the same procedure as in Example 1 to obtain 91 g of a polymer (1-2). NM
The composition ratio calculated from R is methyl methacrylate unit 3
The content was 2.2% by weight and sodium p-styrenesulfonate unit was 9.2% by weight.

Example 3 As monomers, 30 g of methyl methacrylate, 10 g of n-butyl acrylate, 10 g of sodium p-styrenesulfonate and polyethylene oxide compound (3-1)
Polymerization was performed in the same manner as in Example 1 except that 50 g was used. It was collected and dried by the same procedure as in Example 1 to obtain 87 g of a polymer (1-3). The compositional ratio calculated from NMR was 31.2% by weight of methyl methacrylate unit, 11.4% by weight of n-butyl acrylate unit, and 8.6% by weight of p-sodium styrenesulfonate unit.

Example 4 Same as Example 1 except that 30 g of methyl methacrylate, 10 g of 2-ethylhexyl acrylate, 10 g of sodium p-styrenesulfonate and 50 g of polyethylene oxide compound (3-1) were used as monomers. Was polymerized. Recovered and dried by the same procedure as in Example 1,
90 g of polymer (1-4) was obtained. The composition ratio calculated from NMR is 32.1% by weight of methyl methacrylate unit,
2-ethylhexyl acrylate unit 10.7% by weight, p
-Sodium styrene sulfonate unit was 8.8% by weight.

Example 5 As a monomer, 2-ethylhexyl acrylate 30 was used.
Polymerization was performed in the same manner as in Example 1 except that g, 10 g of sodium p-styrenesulfonate and 60 g of polyethylene oxide compound (3-2) were used. It was collected and dried by the same procedure as in Example 1 to obtain 83 g of Polymer (1-5). The composition ratio calculated from NMR is 2-
Ethylhexyl unit was 32.1% by weight, and sodium p-styrenesulfonate unit was 9.6% by weight.

Example 6 Polymerization was carried out in the same manner as in Example 1 except that 65 g of methyl methacrylate, 10 g of sodium p-styrenesulfonate and 25 g of polyethylene oxide compound (3-1) were used as the monomers. It was recovered and dried by the same procedure as in Example 1 to obtain 92 g of a polymer (1-6). NMR
The composition ratio calculated from is the methyl methacrylate unit 6
The content was 9.0% by weight, and the sodium p-styrenesulfonate unit was 8.5% by weight. As shown in Table 1 below, 100 parts by weight of the obtained polymer was melt-kneaded with 0.3 part by weight of a phosphite-based antioxidant (PEP-36 manufactured by Asahi Denka Co., Ltd.) by a twin-screw extruder, and then hot pressed. By making various test pieces by
The flexural modulus and antistatic performance were evaluated. The obtained results including other evaluation results are shown in Table 1.

Example 7 As monomers, 67 g of methyl methacrylate, 3 g of methyl acrylate, 10 parts of sodium p-styrenesulfonate were used.
g and polyethylene oxide compound (3-1) 20 g
Polymerization was carried out in the same manner as in Example 1 except that It was recovered and dried in the same procedure as in Example 1 to obtain 90 g of a polymer (1-7). The composition ratio calculated from NMR was 69.6% by weight of methyl methacrylate unit, 2.7% by weight of methyl acrylate unit, and 8.9% by weight of sodium p-styrenesulfonate unit. As shown in Table 1 below,
0.3 parts by weight of a phosphite antioxidant (PEP-36 manufactured by Asahi Denka Co., Ltd.) was melt-kneaded with 100 parts by weight of the obtained polymer in a twin-screw extruder, and various test pieces were prepared by hot pressing. The flexural modulus and antistatic performance were evaluated. The obtained results including other evaluation results are shown in Table 1.

Example 8 As monomers, 40 g of methyl methacrylate, 30 g of n-butyl methacrylate, 10 g of sodium p-styrenesulfonate and polyethylene oxide compound (3-
1) Polymerization was performed in the same manner as in Example 1 except that 20 g was used. Recovered and dried by the same procedure as in Example 1, 88 g
The polymer (1-8) of was obtained. The composition ratio calculated from NMR was 41.1% by weight of methyl methacrylate unit, 28.4% by weight of n-butyl methacrylate unit and 9.4% by weight of p-sodium styrenesulfonate unit.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that 40 g of methyl methacrylate and 60 g of polyethylene oxide compound (3-1) were used as monomers. The procedure of Example 1 was followed by collecting and drying to obtain 81 g of polymer (1′-1). The composition ratio calculated from NMR was 42.7% by weight of methyl methacrylate unit. As shown in Table 1 below, 100 parts by weight of the obtained polymer was melt-kneaded with 0.3 part by weight of a phosphite-based antioxidant (PEP-36 manufactured by Asahi Denka Co., Ltd.) by a twin-screw extruder, and then hot pressed. Various test pieces were prepared according to the above, and the flexural modulus and antistatic performance were evaluated. The obtained results including other evaluation results are shown in Table 1.

Comparative Example 2 Polymerization was carried out in the same manner as in Example 1 except that 70 g of methyl methacrylate and 30 g of sodium p-styrenesulfonate were used as the monomers. It was dripped into 2N-hydrochloric acid to collect it, then washed with water, and then vacuum dried at 80 ° C. to obtain 9
4g of polymer (1'-2) was obtained. The compositional ratio calculated from NMR is 74.0% by weight of methyl methacrylate unit,
P-sodium styrenesulfonate unit 26.0% by weight
Met. However, this polymer could not be melted below 280 ° C.

Comparative Example 3 As the monomer, 70 g of methyl methacrylate and 30 g of a polyethylene glycol compound in which one end of the molecular chain was blocked with a methyl group and the other end with a methacryloyl group (manufactured by Kyoei Chemical Co., Ltd., the degree of polymerization of polyethylene glycol portion was 20) were used. Polymerization was performed in the same manner as in Example 1 except for the above. It was recovered, dried and vacuum dried at 80 ° C. in the same procedure as in Example 1 to obtain 94 g of a polymer (1′-3). The composition ratio calculated from NMR was 79.2% by weight of methyl methacrylate unit. As shown in Table 1 below, 100 parts by weight of the obtained polymer was added to a phosphite-based antioxidant (PEP-3 manufactured by Asahi Denka Co., Ltd.).
6) 0.3 parts by weight was melt-kneaded with a twin-screw extruder, and various test pieces were prepared by hot pressing to evaluate flexural modulus and antistatic performance. The obtained results including other evaluation results are shown in Table 1.

[0048]

[Table 1]

Comparative Example 4 As a monomer, 20 g of methyl methacrylate, 20 g of sodium p-styrenesulfonate and a polyethylene glycol compound having one end of the molecular chain blocked with a methyl group and the other end with a methacryloyl group (manufactured by Kyoei Chemical Co., Ltd. Polymerization was carried out in the same manner as in Example 1 except that 60 g of a polymerization degree of 20) was used. It was recovered and dried in the same procedure as in Example 1 to obtain 77 g of a polymer (1′-4). NM
The composition ratio calculated from R is 2 units of methyl methacrylate unit.
The amount was 8.4% by weight and the sodium p-styrenesulfonate unit was 31.9% by weight.

Comparative Example 5 In a pressure resistant polymerization vessel, 30 g of ion-exchanged water and 0.0 of ferrous sulfate were placed.
004g, ethylenediaminetetraacetic acid 0.0006
g, sodium pyrophosphate 0.05 g and sodium dodecylbenzene sulfonate 0.1 g, then 1,3-butadiene 12 g, methyl acrylate 8 g, polyethylene with one end of the molecular chain blocked with a methyl group and the other end with a methacryloyl group Glycol compound (manufactured by Kyoei Chemical Co., Ltd., degree of polymerization of polyethylene glycol part 20) 10 g and p
0.4 g of divinylbenzene was charged and polymerized at 50 ° C. for 12 hours to produce a polymer latex. afterwards,
In the obtained latex, 65 g of methyl methacrylate, 5 g of methyl acrylate, 0.4 of n-dodecyl mercaptan
g, potassium persulfate 0.072 g and deionized water 27
The second stage polymerization was carried out by adding 0 g. The obtained latex was treated with an acid, and the precipitated polymer particles were washed with water and dehydrated and dried to obtain a fine particle powder. This powder was vacuum dried at 80 ° C. to obtain 94 g of a polymer (1′-5). The composition ratio calculated from NMR was 79.2% by weight of methyl methacrylate unit.

Examples 9-18, Comparative Examples 6-10 Examples 1-5 or 8; Polymers obtained according to Comparative Examples 1, 3, 4 or 5; or acrylic resins are shown in Tables 2 and 3, respectively. With the composition as shown, the resin was kneaded with another resin and an antioxidant in a twin-screw extruder, and various test pieces were prepared by hot pressing, and the flexural modulus and antistatic performance were evaluated. The obtained results including other evaluation results are shown in Tables 2 and 3.

However, the contents of the abbreviations used in Tables 2 and 3 are as follows. PEP-36: Asahi Denka Co., Ltd. phosphite-based antioxidant Acrylic resin: Kuraray parapet EH ABS: Acrylonitrile-butadiene-styrene resin (Ube Saikon Cycorac T) PBT: Polybutylene terephthalate resin (phenol / tetrachloroethane (weight ratio) 1/1) Intrinsic viscosity in mixed solvent: 0.60 dl / g) PC: Polycarbonate resin (Teflon A2200 manufactured by Idemitsu Petrochemical Co., Ltd.)

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

EFFECT OF THE INVENTION The copolymer of the present invention has excellent antistatic performance and thermal stability, and therefore can be blended as an antistatic agent for a wide range of resins. Maintains good antistatic performance for a long period of time. Further, when the copolymer of the present invention is blended with other resin, the obtained resin composition can highly retain the original elastic modulus of the resin.

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Claims (4)

[Claims] 1. A unit (A) mainly derived from a compound having a sulfonic acid group and an ethylenically unsaturated bond,
The unit (B) represented by the formula (1) and a unit (C) derived from a compound having an ethylenically unsaturated bond and different from (A) and (B), and having a weight percentage of (A). Is 5 to 30%, and the weight percentage of (B) is 10
A copolymer or a salt thereof, characterized in that the copolymer has a weight percentage of (A) and a weight percentage of (B) of 20 to 90%. Embedded image (In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group which may have a hydroxyl group, and R ³
Represents a divalent saturated aliphatic hydrocarbon group having 2 to 4 carbon atoms,
R ⁴ represents a monovalent hydrocarbon group having 4 to 30 carbon atoms, and n represents a number of 3 to 200 in average value. ) 2. A unit (A) mainly derived from a compound having a sulfonic acid group and an ethylenically unsaturated bond,
The unit (B) represented by the formula (1) and a unit (C) derived from a compound having an ethylenically unsaturated bond and different from (A) and (B), and having a weight percentage of (A). Is 5 to 30%, and the weight percentage of (B) is 10
An antistatic agent comprising a copolymer or a salt thereof, which is ˜70% and the sum of the weight percentage of (A) and the weight percentage of (B) is 20 to 90%. Embedded image (In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group which may have a hydroxyl group, and R ³
Represents a divalent saturated aliphatic hydrocarbon group having 2 to 4 carbon atoms,
R ⁴ represents a monovalent hydrocarbon group having 4 to 30 carbon atoms, and n represents a number of 3 to 200 in average value. ) 3. A thermoplastic resin (100 parts by weight), a unit (A) derived from a compound having a sulfonic acid group and an ethylenically unsaturated bond, a unit (B) represented by the formula (1) and ethylene. Derived from a compound having a polyunsaturated bond and composed of a unit (C) different from (A) and (B), the weight percentage of (A) is 5 to 30%, and the weight percentage of (B) is Is 10 to 70%, and the sum of the weight percentage of (A) and the weight percentage of (B) is 20 to
A resin composition containing 1 to 80 parts by weight of a 90% copolymer or its salt. Embedded image (In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group which may have a hydroxyl group, and R ³
Represents a divalent saturated aliphatic hydrocarbon group having 2 to 4 carbon atoms,
R ⁴ represents a monovalent hydrocarbon group having 4 to 30 carbon atoms, and n represents a number of 3 to 200 in average value. ) 4. The resin composition according to claim 3, wherein the thermoplastic resin is an acrylic resin.