JP3120125B2 - Thermoplastic 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 a thermoplastic resin composition having excellent antistatic properties, mechanical strength and appearance of a molded product.

[0002]

2. Description of the Related Art Various thermoplastic resins such as polyolefin, (rubber reinforced) styrene resin, acrylic resin and engineering plastic have excellent moldability and mechanical strength, and are widely used in automobile parts and electric parts. However, there are problems such as inferior antistatic properties due to the use of an insulator, and improvement of these is strongly desired.

[0003]

A method of kneading an antistatic agent, carbon black, and metal powder is known as an antistatic means, but the method of kneading the antistatic agent is as follows.
There are problems such as contamination of molded articles due to bleed out of the incorporated antistatic agent, deterioration of appearance, reduction of mechanical strength, deterioration of the antistatic effect due to aging of the incorporated antistatic agent, and carbon black or The method of kneading the metal powder has drawbacks such as the molded article being colored black and not being able to be colored to an arbitrary color, or a decrease in moldability and physical properties.

[0004]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have found that a small amount of a specific metal salt is mixed in a mixture of a thermoplastic resin and a thermoplastic polyurethane elastomer. The present inventors have found that a material having excellent antistatic properties and mechanical strength can be obtained, and have reached the present invention.

That is, the present invention relates to a thermoplastic resin (A)
Antistatic obtained by mixing 0.1 to 5 parts by weight of an alkali metal salt of an organic acid (C) with 100 parts by weight of a composition comprising 98 to 75% by weight and 2 to 25% by weight of a thermoplastic polyurethane elastomer (B). An object of the present invention is to provide a thermoplastic resin composition having excellent properties, mechanical strength and appearance of a molded article.

Hereinafter, the present invention will be described in detail.

The thermoplastic resin (A) used in the present invention is not particularly limited. For example, polyolefins such as polyethylene and polypropylene, polystyrene, styrene-acrylonitrile copolymer, ABS resin, and rubber components of ABS resin are composed of EPDM rubber. AES changed to acrylic rubber
Resins, (rubber-reinforced) styrene resins such as AAS resins, acrylic resins such as polymethyl methacrylate, and so-called engineering plastics such as polyacetal, polyphenylene oxide, polycarbonate, polyester, and polyamide. Further, thermoplastic resins obtained by polymer blending these thermoplastic resins can also be used. Among them, a (rubber-reinforced) styrene resin is preferable.

[0008] Next, the thermoplastic polyurethane elastomer (B) used in the present invention is a polyurethane polyurethane comprising repeating segments of linear long-chain urethane units and short-chain urethane units randomly bonded head to tail by urethane bonds. A polymer, wherein the long-chain urethane unit can be represented by the following formula:

[0009]

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The short-chain urethane unit can be represented by the following chemical formula 2.

[0011]

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In these Chemical Formulas 1 and 2, E is about 50
A divalent group remaining after removal of terminal hydroxyl groups from at least one long-chain glycol having a molecular weight of 0 to 6000, and Z remaining after removal of isocyanate groups from at least one diisocyanate having a molecular weight of less than about 700 G is a divalent group and G is a divalent group remaining after removal of hydroxyl groups from at least one low molecular weight diol having a molecular weight of less than about 350.

The diisocyanates having a molecular weight of less than about 700 are aliphatic, cycloaliphatic, aromatic-substituted aliphatic, aromatic or heterocyclic diisocyanates such as hexamethylene-1,6-diisocyanate,
2,2,4- or 2,2,6-trimethylhexamethylene-1,6-diisocyanate, 1-isocyanato-
3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cis- or trans-cyclohexane-
1,4-diisocyanate, dicyclohexylmethane-
4,4′-diisocyanate, ω, ω′-diisocyanatocyclohexane, isopropylidene dicyclohexyl-1,4-diisocyanate, dimer diisocyanate, tolylene-2,4- or -2,6-diisocyanate, diphenylmethane-2,4 -Or -4,4'-
Diisocyanate, naphthylene-1,5-diisocyanate, pytylene diisocyanate, dianisidine diisocyanate, m- or p-phenylenediisocyanate, xylylene-1,3- or -1,4-diisocyanate, azobenzene-4,4'-diisocyanate, diphenyl Sulfone-4,4′-diisocyanate, diphenylether-4,4′-diisocyanate, N, N-bis (ω-isocyanatopropyl) oxadiazinetrione, and the like. Good.

Diols having a molecular weight of less than about 350 which react with these diisocyanates to form short chain urethane units are aliphatic, cycloaliphatic, aromatic-substituted aliphatic or heterocyclic diols, such as , Ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 2,3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-
Dimethyl-1,3-propanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, 1,4-bis (beta-hydroxyethoxy) benzene, p-xylylenediol, phenyldiethanolamine, methyldiethanolamine,
3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,
5] undecane, α, α '-(isopropylidene-p
-Phenylene) bis- (ω-hydroxypropylene) and the like. These may be used by copolymerizing two or more kinds.

The long-chain glycol which forms a long-chain urethane unit by reacting with a diisocyanate having a molecular weight of about 700 or less includes, for example, polyester diol, polyoxyalkylene diol, polycarbonate diol, polybutadiene diol, polyolefin diol, polythioether diol, polyacetal. And diols.

Suitable polyester diols include, for example, those obtained from dicarboxylic acids and diols. Examples of suitable dicarboxylic acids include
Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, pracylic acid, maleic acid, fumaric acid, glutaconic acid, α-butyl-α-ethyl-glutaric acid and the like All can be used. Suitable diols include, for example, ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,4-pentanediol, 1,3-pentanediol, , 6-hexanediol, 1,7-
Heptanediol, 1,8-octanediol, 1,9
-Nonanediol, 2,2-dimethyl-1,3-propanediol, 2,2-dimethyl-3-hydroxypropyl-2,2-dimethyl-3-hydroxypropionate, dimethylethanolamine and the like All can be used.

Further, suitable polyester diols include those obtained by reacting hydroxycarboxylic acid with the above diol and those obtained by ring-opening polymerization of lactone using the above diol as an initiator. it can. Examples of suitable hydroxycarboxylic acids include lactic acid, 3-hydroxypropionic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 5-hydroxyvaleric acid,
Hydroxycaproic acid, 3-hydroxy-4-methylenanthic acid, 4-hydroxycapryloic acid and the like can all be used. Suitable lactones include beta-propiolactone, gamma-butyrolactone, eta-valerolactone, epsilon-caprolactone, gamma-caprylolactone, 3-methyl-eta-valerolactone, and the like.

Suitable polyoxyalkylene diols include, for example, diols such as those described above for the preparation of polyester diols, or water and the like, starting with cyclic oxides such as ethylene oxide, propylene oxide, trimethylene oxide, and tetrahydrofuran. Those produced by polymerizing or copolymerizing ether can be used.

Suitable polycarbonate diols include, for example, those prepared by the transesterification of diols and carbonates such as those described above for the preparation of polyester diols, for example, diethyl carbonate, dipropyl carbonate, ethylene carbonate, diphenyl carbonate. Anything like that can be used.

Suitable polybutadiene diols include:
Poly-1,4-butadiene having a hydroxy group at a terminal,
All such as poly-1,2-butadiene or a copolymer thereof, polybutadiene-CO-acrylonitrile, polybutadiene-CO-styrene and the like can be used.

Suitable polyolefin diols include:
All diols obtained by hydrogenation reduction of the above-mentioned polybutadiene diol and all long-chain diols having a saturated hydrocarbon chain such as a polyethylene propylene copolymer having a hydroxyl group at a terminal can be used.

Suitable polythioether diols include, for example, all condensation products of thioglycol or the reaction products of the abovementioned diols with any other suitable thioether glycol for the production of polyester diols. Further, the long-chain diol,
Although they can be used alone or as a mixture of two or more, among them, polyoxyalkylene diol and polythioether diol are particularly preferable. In the reaction between diisocyanate and diols, the preferred molar ratio of isocyanate group / hydroxyl group is 0.9 to 1.2, particularly preferably 0.98 to 1.03. In addition, the molar ratio of long-chain diol / short-chain diol can be changed in a wide range according to the type of raw material and the purpose of use of the polyurethane elastomer.

The alkali metal salt (C) of an organic acid used in the present invention includes lithium trifluoroacetate, sodium trifluoroacetate, potassium trifluoroacetate, lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, trifluoromethanesulfonate. Potassium acetate, lithium acetate, sodium acetate, potassium acetate, lithium dodecylbenzenesulfonate, potassium dodecylbenzenesulfonate, sodium dodecylbenzenesulfonate, lithium dodecylsulfonate, potassium dodecylsulfonate, sodium dodecylsulfonate, and the like. Alternatively, two or more kinds may be used in combination. Among them, an alkali metal salt of a nucleus-substituted benzenesulfonic acid such as dodecylbenzenesulfonic acid is particularly preferable.

The mixed composition of the thermoplastic resin (A), the thermoplastic polyurethane elastomer (B) and the alkali metal salt of an organic acid (C) in the thermoplastic resin composition of the present invention is 98-75 for the thermoplastic resin (A). % By weight, preferably 95 to 80% by weight, 100% by weight of a composition comprising 2 to 25% by weight, preferably 5 to 20% by weight of the thermoplastic polyurethane elastomer (B). 0.1 to 5 parts by weight.

When the content of the thermoplastic polyurethane elastomer is less than 2% by weight (more than 98% by weight of the thermoplastic resin), the mechanical strength and the antistatic property are inferior. When the content exceeds 25% by weight (less than 75% by weight of the thermoplastic resin), Poor target strength.

When the amount of the alkali metal salt of the organic acid is less than 0.1 part by weight, the antistatic property is poor. When the amount exceeds 5 parts by weight, the molded article is undesirably colored.

As a method of mixing the thermoplastic resin, the thermoplastic polyurethane elastomer and the alkali metal salt of the organic acid, known methods such as a Banbury mixer, a roll, and an extruder can be adopted.

In addition, a known impact modifier (impact modifier) can be further added at the time of mixing for the purpose of increasing the impact resistance of the composition.

In addition, at the time of mixing, if necessary, an antioxidant,
UV absorbers, light stabilizers, lubricants, dyes, pigments, plasticizers,
Additives such as flame retardants, release agents, glass fibers, metal fibers, carbon fibers, and metal flakes, reinforcing agents, fillers, and the like can be added.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

In the Examples and Comparative Examples, "parts" and "%" are based on weight, and are used thermoplastic resins, thermoplastic polyurethane elastomers, alkali metal salts of organic acids and antistatic agents. Is a substance shown below.

Thermoplastic resin (A) ABS resin An ABS graft copolymer comprising 50 parts of polybutadiene (solid content), 15 parts of acrylonitrile and 35 parts of styrene was produced by a known emulsion polymerization method. Similarly, a SAN copolymer comprising 25 parts of acrylonitrile and 75 parts of styrene was produced by an emulsion polymerization method. The above graft copolymer and SAN copolymer were mixed at a ratio (part) of 20/80 to obtain an ABS resin.

AES resin An AE comprising an iodine value of 15.8, a Mooney viscosity of 67, a propylene content of 50% by weight, 50 parts of EPDM containing ethylidene norbornene as a diene component, 15 parts of acrylonitrile and 35 parts of styrene by a known solution polymerization method.
An S-graft copolymer was produced. The AES graft copolymer and the SAN copolymer used in the ABS resin were mixed in 20 /
The mixture was mixed at a ratio of 80 (parts) to obtain an AES resin.

Thermoplastic polyurethane elastomer (B) B-1: A prepolymer is prepared from 4,4'-diphenylmethane diisocyanate as a diisocyanate and polyethylene glycol having a weight average molecular weight of about 1000 as a long chain glycol, and then a short chain glycol is used. Ethylene glycol was added to increase the molecular weight to obtain an elastomer comprising a long-chain urethane unit represented by Chemical Formula 3 and a short-chain urethane unit represented by Chemical Formula 4.

[0035]

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[0036]

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The ratio of long chain urethane units to short chain urethane units was 85/15, and the weight average molecular weight was about 500,000.

B-2: In B-1, the ratio of the long chain urethane unit to the short chain urethane unit was changed to 70/30 by changing the ratio of the prepolymer and ethylene glycol used.
To obtain an elastomer.

B-3: An elastomer was obtained in the same manner as in B-1, except that polytetramethylene glycol having a weight average molecular weight of about 1000 was used as the long-chain glycol.

Alkali metal salt of organic acid (C) DBS: Sodium dodecylbenzene sulfonate LAS: Sodium linear alkyl sulfonate

[0041]

Examples 1 to 8 and Comparative Examples 1 to 6 The thermoplastic resin (A), the thermoplastic polyurethane elastomer (B), the alkali metal salt of an organic acid (C) and the antistatic agent were added in the proportions shown in Table 1. Mix, melt and mix with a Banbury mixer,
Granulated. After granulation, various test pieces were molded using a 3.5 ounce injection molding machine. (Set the molding temperature to 210 ° C.)
The quality of the obtained resin composition was evaluated by the following method.
The results are shown in Table 1.

O Impact strength (Izod with notch): AS
TM D-256 (23 ° C, Kg · cm / cm)

O Flexural modulus: ASTM D-790 (2
3 ° C, Kg / cm ² )

O Half-life: (1) Before treatment: 50 mm × 50 mm
A molded product having a size of 3 mm was prepared, and after conditioning at 23 ° C. and a relative humidity of 55% for 24 hours, the half-life of the charged voltage was measured using a static honest meter (manufactured by Shisido Electrostatics) (sec).
Was measured. (2) After treatment: After molding the same molded article as in (1), the molded article was immersed in running water for 10 minutes to remove water on the surface, and conditioned at 23 ° C. and 55% relative humidity for 24 hours. ), The half-life (seconds) of the charged voltage was measured.

O Appearance of molded article: A molded article of 50 mm × 50 mm × 3 mm was molded, and the presence or absence of silver streaks and coloring was visually confirmed.

[0046]

[Table 1]

Claims (1)

(57) [Claims] 1. 98 to 75% by weight of a thermoplastic resin (A) and 2 to 25 of a thermoplastic polyurethane elastomer (B)
A thermoplastic resin composition comprising 0.1 to 5 parts by weight of an alkali metal salt of an organic acid (C) per 100 parts by weight of a composition of 100% by weight.