JPH08157682A - Transparent and permanently antistatic resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition, comprising an MBS resin, etc., containing methyl methacrylate, etc., a cross-linked type thermoplastic polyethylene oxide and an amine-based surfactant without deteriorating resin physical properties and having antistatic effects unlost by washing with water. CONSTITUTION: This resin composition is obtained by blending (A) an MBS or an MABS resin comprising 48-70wt.% methyl methacrylate unit, 25-50wt.% styrene unit, 2-20wt.% butadiene unit and 0-5wt.% acrylonitrile unit with (B) a cross-linked type thermoplastic polyethylene oxide prepared by reacting a water-soluble resin polyethylene oxide with one or more compounds having a mono- or a polyisocyanate group and (C) an amine-based surfactant. The amounts of the components are 85-98wt.% component (A) and 2-15wt.% component (B) when the sum total of the components (A) and (B) is 100wt.%. The amount of the component (C) is 0.2-3wt.% based on 100wt.% sum total of the components (A) and (B). The resin composition does not lose antistatic effects even by washing with water without deteriorating physical properties and causing delamination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having a permanent antistatic property and transparency and having a good balance of physical properties. Further, it is a resin composition that does not cause delamination when formed into a molded product.

[0002]

2. Description of the Related Art Generally, most plastics have a high electric insulating property and are easily charged by friction or the like, so that there is a problem in that dust or dirt adheres to the molded product, sheet, film or the like to deteriorate its appearance. Especially in applications requiring transparency,
The dust and dirt that adheres to it is noticeable, which is a big problem. In addition, recently, with the remarkable development of electronic products such as video, computers, OA equipment, etc., plastic products are used for these products, so that noise or I caused by static electricity is generated in the products.
Damage of C parts has become an important issue.

In order to prevent such damage to the plastic due to static electricity, (1) an internal mixing method of an antistatic agent, (2) an external coating method of an antistatic agent, and (3) a method using a static eliminator A variety of antistatic treatment methods have been implemented.

However, in the internal kneading method of the antistatic agent of (1), the low molecular weight surfactant which is generally used as the antistatic agent is removed by washing the surface of the molded article with water or rubbing, etc. The effect is lost, and it is difficult to maintain the permanent antistatic property.

Also in the external coating method of the antistatic agent of (2), the applied antistatic agent is easily removed by washing the surface of the molded product with water, rubbing, etc., and the above-mentioned internal kneading method of the antistatic agent. As with the above, the antistatic effect is lost, and it is difficult to provide permanent antistatic performance. Also, this method requires a surface coating step, unlike the internal kneading method, and thus the cost is high.

Further, the method of using the static eliminator of (3) includes a corona discharge type and a radioisotope type. The former is a danger of ignition due to spark discharge, and the latter is limited in use by using radiation. There are few examples that have been put to practical use. In addition, this method simply has a function of removing static electricity and does not have permanent antistatic performance.

As another method for imparting a permanent antistatic property, there is a method of kneading a large amount of carbon black, metal powder, metal fibers and the like, but this method imparts a sufficient antistatic effect. On the other hand, on the other hand, not only the moldability, impact resistance, etc. are deteriorated, but also a transparent molded article cannot be obtained.

On the other hand, JP-A-61-73753, JP-A-61-73765 and JP-A-61-24624.
As disclosed in Japanese Patent Publication No. 4), a method of imparting a permanent antistatic property by mixing a polyether ester amide elastomer with a thermoplastic resin is known. However, because of poor compatibility, the strength of a molded product is reduced and delamination is caused. There is a problem that causes.

[0009]

[Problems to be Solved by the Invention]
The object of the present invention is not to lose the excellent antistatic effect even when washed with water, without deteriorating the physical properties such as impact strength of the resin, heat resistance and molding processability, and delamination when formed into a molded product. It is intended to provide a thermoplastic resin composition having excellent permanent antistatic property and excellent transparency.

[0010]

As a result of earnest studies for this purpose, the present inventor has found that a thermoplastic resin that retains excellent permanent antistatic properties even when washed with water and has a good balance of transparency and physical properties. The resin composition was achieved by blending a specific MBS resin or MABS resin with a specific crosslinkable thermoplastic polyethylene oxide and a specific amount of an amine surfactant.

That is, in the present invention, the methyl methacrylate unit is 48 to 70% by weight and the styrene unit is 25 to 50% by weight.
MBS resin or MABS resin (A) consisting of 2% to 20% by weight of butadiene unit and 0 to 5% by weight of acrylonitrile unit, and at least one kind having a mono- or polyisocyanate group in water-soluble resin polyethylene oxide. Which comprises a cross-linkable thermoplastic polyethylene oxide (B) obtained by reacting the above compound and an amine-based surfactant (C), the MBS resin or MABS resin (A)
And the cross-linking type thermoplastic polyethylene oxide (B) is 100% by weight, the MBS resin or MABS resin (A) is 85 to 98% by weight, and the cross-linking type thermoplastic polyethylene oxide (B) is 2 to 15%. % Of the total of the MBS resin or MABS resin (A) and the crosslinkable thermoplastic polyethylene oxide (B), and the amine surfactant (C) is 0.2 to 3% by weight. This can be achieved by using a transparent permanent antistatic resin composition that is

The present invention will be described in more detail below. M
The BS resin is known as a copolymer resin composed of a methyl methacrylate unit, a styrene unit and a butadiene unit, and the MABS resin is known as a copolymer resin composed of a methyl methacrylate unit, a styrene unit, a butadiene unit and an acrylonitrile unit. The resin composition of the MBS resin or MABS resin used in the present invention has a methyl methacrylate unit of 48 to 70% by weight, a styrene unit of 25 to 50% by weight, a butadiene unit of 2 to 20% by weight, and acrylonitrile. It is a resin whose unit is 0 to 5% by weight (MBS resin when 0% by weight), and this composition is preferable because the transparency of the resin composition is particularly excellent.

The crosslinkable thermoplastic polyethylene oxide (B) used in the present invention is obtained by reacting a water-soluble resin polyethylene oxide with a small amount of at least one compound having a mono- or polyisocyanate group. .

The water-soluble resin polyethylene oxide can copolymerize ethylene oxide with propylene oxide, butylene oxide and other copolymerizable components as long as the water solubility is not lost. The chain may contain an alkylene group or an alkyl group.
These may be used alone or in a mixture of two or more. When the number average molecular weight of the water-soluble resin polyethylene oxide is 2000 or more and less than 100,000, the resin composition has excellent transparent permanent antistatic performance and mechanical properties such as strength, and more preferably has a number average molecular weight of 5,000 to 800.
When 00, particularly excellent characteristics are obtained. Number average molecular weight is 20
If it is less than 00, the swelling property in water and the ability to capture the amine-based surfactant are lowered, and thus the holding power of the permanent antistatic property is lowered, and if it is 100000 or more, the compatibility or transparency with the MBS resin or the MABS resin is lowered, This tends to cause a decrease in strength of the molded product and delamination.

On the other hand, the compound having a mono- or polyisocyanate group is an organic compound containing one or two or more isocyanate groups in the same molecular weight, such as n-propyl isocyanate, n-butyl isocyanate, n-hexyl isocyanate, dodecyl isocyanate, octadecyl isocyanate,
Cyclohexyl isocyanate, methylcyclohexyl isocyanate, benzyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, p
-Nitrophenyl isocyanate, 2-chloroethyl isocyanate, stearoyl isocyanate, p-toluosulfonyl isocyanate, isopropenyldimethylbenzyl isocyanate, propane diisocyanate, hexane diisocyanate, decane diisocyanate, w, w'-dipropyl ether diisocyanate,
Thiodiethyl diisocyanate, hexafluoropropane diisocyanate, 1,3-dimethylbenzene-w,
w'-diisocyanate, 1,4-dimethylnaphthalene-w, w'-diisocyanate, 2,4-tolylene diisocyanate, 1,3-dimethylbenzene-2,4-diisocyanate, 3,3'-dimethyldiphenyl-4,
4'-diisocyanate, tetramethylxylene diisocyanate, naphthalene-1,4-diisocyanate,
Biphenyl-4,4'-diisocyanate, 2-nitrobiphenyl-4,4'-diisocyanate, 3,3'-
Dimethoxybiphenyl-4,4'-diisocyanate,
Diphenylmethane-4,4'-diisocyanate, dianisidine diisocyanate, diphenyl ether-4,
4'-diisocyanate, bitolylene diisocyanate, isophorone diisocyanate, lysine diisocyanate methyl ester, metaxylylene diisocyanate, isopropylidene bis (4,4'-cyclohexyl isocyanate), dimer acid diisocyanate, cyclohexylmethane diisocyanate, 3,3'-dichloro Diphenyldimethylmethane-4,4'-diisocyanate, 1-methylbenzene-2,4,6-triisocyanate, naphthalene-1,3,7-triisocyanate, biphenyl-2,4,4'-triisocyanate,
Triphenylmethane-4,4 ', 4 "-triisocyanate, 4,4', 4" -triisocyanate phenyl thiophosphate, polymeric diphenylmethane diisocyanate and the like can be mentioned. These may be used alone or in combination of two or more for the reaction.

As a general method for reacting at least one compound having a mono- or polyisocyanate group with a polyethylene oxide resin, there is a method of reacting in a solution at a temperature of 50 to 150 ° C. in a solvent such as nitromethane. can give.

The amount of the cross-linkable thermoplastic polyethylene oxide (B) used in the present invention is the MBS resin or M
It is 2 to 15% by weight, and particularly preferably 4 to 10% by weight, based on 100% by weight of the total of the ABS resin (A) and the crosslinkable thermoplastic polyethylene oxide (B). If it is less than 2% by weight, excellent permanent antistatic property cannot be imparted, and
If the content exceeds 10% by weight, the rigidity (flexural modulus) of the molded product is lowered, the heat resistance is lowered, and the molded product is delaminated, which is not preferable.

As the amine-based surfactant (C) used in the present invention, particularly, N, N'-bis (2-hydroxyethyl) alkylamine, polyoxyethylenealkylamine, polyoxyethylenealkylamine When an amine-based surfactant such as fatty acid ester is used,
It is preferable because the resin composition has excellent permanent antistatic performance, mechanical properties such as transparency and strength.

The amount of the amine-based surfactant (C) used in the present invention is the same as that of the MBS resin or MABS resin (A).
And 1 of cross-linked thermoplastic polyethylene oxide (B)
It is 0.2 to 3% by weight, preferably 0.5 to 1.5% by weight, based on 00% by weight. If it is less than 0.2% by weight, excellent permanent antistatic property cannot be imparted, and if it exceeds 3% by weight, the heat resistance inherent to the resin is lowered, which is not preferable.

Further, the resin composition of the present invention may be mixed with other thermoplastic resins such as polyphenylene oxide, polycarbonate, nylon resin, polybutylene terephthalate, etc. to improve the performance as a molding resin. .

If desired, stabilizers, flame retardants, weathering agents, antistatic agents, fillers, plasticizers, lubricants and colorants may be added to the thermoplastic resin composition of the present invention. .

The resin composition of the present invention can be produced using a usual melt-kneading machine. Examples of the melt-kneading device that can be suitably used include a screw extruder, a Banbury mixer, a cokneader, and a mixing roll.
The MBS resin or MABS resin (A), the crosslinkable thermoplastic polyethylene oxide (B) and the amine-based surfactant (C) are not particularly specified in the order of charging, and may be charged all at once.

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the scope of the present invention is not limited by the examples as long as the gist thereof is not exceeded. The MBS resin or MABS resin (A), crosslinkable thermoplastic polyethylene oxide (B) and surfactant (C) used are as follows. B) and the surfactant (C) are as follows.

MBS or MABS resin (A) (1) A styrene-butadiene copolymer having a styrene content of 25% by weight (a product manufactured by Asahi Kasei Co., Ltd.) in a reaction vessel equipped with a stirrer having a fiddler blade, a thermometer, and a reflux condenser. Name Tafuden 2000) 6 parts by weight of styrene monomer 40 parts by weight and M
The MA monomer was dissolved in 54 parts by weight, and 0.2 part by weight of t-dodecyl mercaptan as a molecular weight modifier and 0.04 part by weight of benzoyl peroxide as a polymerization initiator were added thereto, and the homogeneous mixture was stirred. Heated to 90 ° C.
When the conversion of polymerization reached 30%, the reaction mixture was cooled to stop the reaction. Then, 0.2 part by weight of dicumyl peroxide was newly added to the reaction mixture as a polymerization initiator, and then stirred and dispersed in 200 parts by weight of an aqueous solution containing 1 part by weight of tricalcium phosphate as a suspension stabilizer, Polymerization was carried out by heating at 100 ° C. for 2 hours, 115 ° C. for 3.5 hours, and 130 ° C. for 2.5 hours. After the reaction,
After dehydration, washing, and drying, MBS resin beads were obtained (resin composition: styrene unit / MMA unit / butadiene unit =
41.5% by weight / 54.0% by weight / 4.5% by weight) (hereinafter referred to as A-1). (2) Other than using 6 parts by weight of a styrene-butadiene copolymer having a styrene content of 18% by weight (Tafden 1000 manufactured by Asahi Kasei Co., Ltd.), 36 parts by weight of a styrene monomer and 58 parts by weight of an MMA monomer ( MBS resin beads were obtained in the same manner as in (1) (resin composition: styrene unit / MMA unit / butadiene unit = 37.1% by weight / 58.0% by weight / 4.
9% by weight) (hereinafter referred to as A-2). (3) 6 parts by weight of a styrene-butadiene copolymer having a styrene content of 25% by weight (trade name Tafden 2000 manufactured by Asahi Kasei Corporation), 41 parts by weight of styrene monomer, 51 parts by weight of MMA monomer and 2 parts by weight of acrylonitrile. Other than that,
MABS resin beads were obtained in the same manner as in (1) (resin composition: styrene unit / MMA unit / butadiene unit / acrylonitrile unit = 42.5% by weight / 51.0% by weight /
4.5% by weight / 2.0% by weight) (hereinafter referred to as A-3). (4) Polybutadiene (Asahi Kasei's Diene 55NF) 5
Parts by weight, styrene monomer 23 parts by weight, MMA monomer 72
MBS resin beads were obtained in the same manner as in (1) except that parts by weight were used (resin composition: styrene unit / MMA unit / butadiene unit = 23.0% by weight / 72.0% by weight / 5.
0% by weight) (hereinafter referred to as A-4). (5) Except that 6 parts by weight of a styrene-butadiene copolymer having a styrene content of 37% by weight (Tafden 4003, trade name, manufactured by Asahi Kasei Corporation), 48 parts by weight of styrene monomer and 46 parts by weight of MMA monomer were used ( MBS resin beads were obtained in the same manner as in (1) (resin composition: styrene unit / MMA unit / butadiene unit = 50.2% by weight / 46.0% by weight / 3.
8% by weight) (hereinafter referred to as A-5).

Crosslinkable thermoplastic polyethylene oxide (B) (1) 100 parts by weight of polyethylene oxide having a number average molecular weight of 60,000 and 0.25 part by weight of triethylenediamine are added to 2400 parts by weight of nitromethane, and the mixture is placed in a nitrogen atmosphere.
After completely dissolving at 0 to 40 ° C., 0.7 part by weight of diphenylmethane-4,4′-diisocyanate was added,
Reaction was carried out at 0 ° C. for 5 hours to obtain a crosslinked thermoplastic polyethylene oxide (hereinafter referred to as B-1). (2) A crosslinked thermoplastic polyethylene oxide was obtained in the same manner as in (1) except that polyethylene oxide having a number average molecular weight of 2500 was used (hereinafter referred to as B-2). (3) A crosslinked thermoplastic polyethylene oxide was obtained in the same manner as in (1) except that polyethylene oxide having a number average molecular weight of 90,000 was used (hereinafter referred to as B-3).

Surfactant (C) (1) Amine-based Surfactant N, N'-bis (2-hydroxyethyl) alkylamine (trade name MIYOCOL 324 manufactured by Miyoshi Yushi Co., Ltd.) was used as a surfactant (hereinafter referred to as C -1). (2) Non-amine-based surfactant Sodium alkyl sulfonate (trade name Dasper 802D manufactured by Miyoshi Yushi Co., Ltd.) was used as a surfactant (hereinafter referred to as C-2).

<Examples 1 to 7> The methyl methacrylate unit obtained by the above method is 48 to 70% by weight, the styrene unit is 25 to 50% by weight, the butadiene unit is 2 to 20% by weight, and the acrylonitrile unit is 0 to 0% by weight. 5% by weight of MBS resin and MABS resin (A-1, A-2 and A-
3), cross-linked thermoplastic polyethylene oxide (B-1,
B-2 and B-3), and an amine-based surfactant (C-
1) was put into a Henschel mixer having a volume of 20 liters according to the formulation shown in Table 1 and blended, and then 220 ° C. using a twin-screw extruder (TEM35B) manufactured by Toshiba Machine Co., Ltd.
Were melted and kneaded to prepare pellets. The obtained pellets are injection molding machines (IS-80CNB) manufactured by Toshiba Machine Co., Ltd.
Table 1 shows the results of Examples in which test pieces for evaluation were prepared by using, and various evaluations were performed using them.

<Comparative Examples 1 to 9> M obtained by the above method
The BS resin (A-1, A-4 and A-5), the crosslinkable thermoplastic polyethylene oxide (B-1), and the surfactant (C-1 and C-2) were blended according to the formulation shown in Table 2. Table 2 shows the results of a comparative example in which pellets were produced, test pieces for evaluation and various evaluations were performed in the same manner as in the examples.

The physical properties were measured by the following methods. (1) Mechanical properties, heat resistance, fluidity and transparency (a) Izod impact strength: Measured according to ASTM D-256. (B) Flexural modulus: Measured according to ASTM D-790. (C) Heat distortion temperature: Measured according to JIS K-6871. (D) Flowability: Melt flow rate (MF) at a temperature of 200 ° C. and a load of 5 kg according to ASTM D-1238.
R) was measured. (E) Transparency: Total light transmittance and haze were measured according to JIS K-6714.

(2) Antistatic Effect The antistatic effect was evaluated by the surface specific resistance value measured using the following two conditions using an injection molded square plate having a thickness of 2 mm. (A) Immediately after molding: The rectangular plate immediately after molding was washed in pure water for 1 minute, sufficiently dried, and then conditioned at a temperature of 23 ° C. and a humidity of 50% RH for 24 hours in accordance with JIS K-6911. The surface specific resistance value was measured. (B) After leaving for 300 days: the square plate after molding is heated at a temperature of 23 ° C.
After leaving it in a humidity of 50% RH for 300 days, in pure water 1
The surface specific resistance value was measured by washing the sample for a sufficient period of time, thoroughly drying it, and conditioned for 24 hours at a temperature of 23 ° C. and a humidity of 50% RH in accordance with JIS K-6911. The correlation between the surface specific resistance (Ω) and the antistatic effect is excellent when the surface specific resistance is 10 ¹⁰ or less. If the surface resistivity exceeds 10 ¹⁰ and 10 ¹³ or less, the antistatic effect is good, but if the surface resistivity exceeds 10 ¹³ and less than 10 ¹⁴ , the antistatic effect is weak, and if the surface resistivity is 10 ¹⁵ or more, antistatic property is obtained. There is no effect. (3) Layered releasability The layered releasability was evaluated by observing a cut surface when an injection-molded square plate having a thickness of 2 mm was folded by hand. On the cut surface, when scale-like fragments were present parallel to the square plate, the evaluation was rated as x, indicating that there was delamination, and the above-mentioned state where there were no fragments and there was no directionality and was cracked was layered. The evaluation is indicated by ◯ as having no peeling property.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

According to the present invention, the methyl methacrylate unit is 48 to 70% by weight, the styrene unit is 25 to 50% by weight, the butadiene unit is 2 to 20% by weight, and the acrylonitrile unit is 0 to 5% by weight. MBS resin or M
The composition comprising ABS resin, cross-linked thermoplastic polyethylene oxide obtained by reacting a water-soluble resin polyethylene oxide with an isocyanate compound, and an amine-based surfactant has a permanent antistatic property as compared with a conventional antistatic resin. It has excellent properties and transparency, does not deteriorate over time, and has an excellent balance of physical properties.

Claims (2)

[Claims] 1. A methyl methacrylate unit of 48 to 70.
% By weight, 25 to 50% by weight of styrene units, 2 to 20% by weight of butadiene units and 0 to acrylonitrile units.
MBS resin or MABS resin (A) consisting of 5% by weight
And a crosslinkable thermoplastic polyethylene oxide (B) obtained by reacting a water-soluble resin polyethylene oxide with at least one kind of compound having a mono- or polyisocyanate group, and an amine-based surfactant (C). When the total of the MBS resin or MABS resin (A) and the cross-linking type thermoplastic polyethylene oxide (B) is 100% by weight, the MBS resin or MABS resin (A) is 85 to 98%.
% By weight, the crosslinkable thermoplastic polyethylene oxide (B) is 2 to 15% by weight, and the MBS resin or M
Transparent permanent antistatic resin composition in which the amine-based surfactant (C) is 0.2 to 3% by weight based on 100% by weight of the total of the ABS resin (A) and the crosslinkable thermoplastic polyethylene oxide (B). . 2. The transparent permanent antistatic resin composition according to claim 1, wherein the water-soluble polyethylene oxide (B) which forms the crosslinked thermoplastic polyethylene oxide has a number average molecular weight of 2000 or more and less than 100,000.