JPH0739537B2 - Polycarbonate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a polycarbonate resin having excellent fluidity, mechanical strength, transparency, and antistatic performance, and particularly useful as an exterior component for office equipment such as optical disk cartridges. It relates to a composition.

[Conventional technology]

Polycarbonate resin has excellent heat resistance and impact resistance, and is widely used in the fields of various machine parts such as OA and office equipment, and electric parts.

Office equipment parts such as dry copy, facsimile, etc.
Particularly in chassis, in addition to dimensional accuracy and mechanical strength, antistatic performance is required in order to prevent troubles due to electrification between the parts and paper. However, conventional mechanical parts such as chassis are not required to have a design property, and any color tone may be used, and rather, black has been favored because it is easy to adjust the color. Therefore, conductive carbon black and carbon fiber have been blended.

For coloring applications other than black, antistatic agents such as sulfonate compounds of alkali metals and alkaline earth metals are used, but they become white and opaque, and the decomposition of the polycarbonate resin easily occurs, and mechanical properties It often damages the

Under such circumstances, examples of the use of the polycarbonate antistatic composition include optical disk cartridges.

That is, since the optical disc performs recording and reproduction with a laser beam focused to 1 μm or less, a slight dust affects recording and reproduction. As a countermeasure for these problems, it is considered that the optical disc is stored in a cartridge and handled as it is, but the double countermeasure of preventing the dust from adhering to the cartridge is also considered. . Impact strength is required for such exterior parts for office equipment, such as cartridges, in order to prevent damage when dropped.

In addition, it is functionally preferable that the internal product of an optical disk cartridge or the like be visible, and it is extremely important in terms of design. In addition, it is often an essential condition for office exterior parts to be transparent and to be visible inside.

However, under the present circumstances, it has been the fact that a resin composition which does not impair the transparency of the polycarbonate resin and has excellent antistatic properties has not been obtained.

[Object of the Invention]

The inventors of the present invention have conducted extensive studies to obtain a resin composition satisfying the required properties of exterior parts for office equipment, that is, mechanical strength, fluidity, antistatic property, and transparency, and as a result, heat resistance and dimensional stability have been improved. The present invention has been achieved by finding a composition that meets the purpose by incorporating a specific amount of a specific compound in an excellent polycarbonate resin.

That is, with respect to 100 parts by weight of the polycarbonate resin, [I] general formula In the polycarbonate resin composition, 0.1 to 20 parts by weight of sulfonic acid phosphonium salt and 0.01 to 1.0 part by weight of [II] phosphite are blended. However,
In [I], R ¹ is an alkyl group having 1 to 40 carbon atoms or an aryl group, R ^{2 to} R ⁵ are hydrogen atoms, an alkyl group having 1 to 10 carbon atoms, or an aryl group, which may be the same or different. May be.

[Structure of Invention]

 The present invention will be specifically described below.

Aromatic polycarbonate resin is a phosgene method of reacting various dihydroxydiaryl compounds with phosgene,
Alternatively, it is a polymer or copolymer obtained by a transesterification method in which a dihydroxydiaryl compound and a carbonic acid ester such as diphenyl carbonate are reacted, and a typical example thereof is 2,2-bis (4-hydroxyphenyl) propane ( Polycarbonate resins produced from bisphenol A) are mentioned.

Examples of the dihydroxydiaryl compound include bisphenol A, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane and 2,2
-Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5dibromo) Phenyl) propane, 2,2-bis (4-hydroxy-
Bis (hydroxyaryl) alkanes such as 3,5 dichlorophenyl) propane, bis (hydroxyaryl) such as 1,1-bis (4-hydroxyphenyl) cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane ) Dihydroxy diaryl ethers such as cycloalkanes, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 4,4'-dihydroxydiphenyl sulfide, 4,4'- Dihydroxydiaryl sulfides such as dihydroxy-3,3′-dimethyldiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfoxide, dihydroxydiaryl sulfoxides such as 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfoxide, 4,4'-dihydroxydipheny Sulfone, 4,
Examples thereof include dihydroxydiarylsulfones such as 4'-dihydroxy-3,3'-dimethyldiphenylsulfone.

These may be used alone or in combination of two or more,
In addition to these, piperazine, dipiperidyl, hydroquinone, resorcin, 4,4'-dihydroxydiphenyl and the like may be mixed and used.

The molecular weight of polycarbonate is greatly related to fluidity, but from the viewpoint of strength, it is preferably 14,000 to 30,000.

Further, the phosphonium sulfonate used in the present invention has a general formula Where R ¹ is an alkyl group or aryl group having 1 to 40 carbon atoms, R ^{2 to} R ⁵ are hydrogen, an alkyl group having 1 to 10 carbon atoms, or an aryl group (these may be the same or different. It is good).

The compound represented by the general formula is a polycarbonate resin.
0.1 to 20 parts by weight, preferably 0.5 to 5 parts by weight per 100 parts by weight
It is compounded in parts by weight. If it is 0.1 parts by weight or less, the antistatic effect cannot be obtained, and if it exceeds 20 parts by weight, the transparency is deteriorated, the mechanical properties are deteriorated, and silver or peeling is likely to occur on the surface of the molded product to easily cause poor appearance.

The above formula R ¹ is an alkyl group or an aryl group, but an aryl group is more preferable from the viewpoints of transparency, heat resistance, influence on the polycarbonate resin, etc., and is derived from, for example, an alkylbenzene or an alkylnaphthalene ring. Group.

Specific compounds include phosphonium dodecyl sulfonate and phosphonium dodecyl benzene sulfonate.

In the present invention, it is necessary that transparency and discoloration at the time of melt molding are small, but the above-mentioned phosphonium salt alone has a drawback that thermal deterioration and discoloration of the polycarbonate resin are easily induced.

Therefore, by adding a small amount of phosphite, the discoloration and deterioration of the polycarbonate resin are remarkably improved.

The phosphite ester which is a component of the composition of the present invention,
General formula P- (OR ") ₃ (In the formula, R" represents an alkyl group having 1 to 30 carbon atoms, an aryl group, an aralkyl group, a cycloalkyl group or an alkylaryl group, which may be the same or different. In addition, R ″ may have a substituent).

Specifically, for example, trioctadecyl phosphite,
Trioctyl phosphite, triphenyl phosphite, tri- (2-methylphenyl) phosphite,
Tri- (4-tert-butylphenyl) phosphite, tri- (2-tert-butylphenyl) phosphite, tri- (2,6-dimethylphenyl) phosphite, tri-
(2,6-Diethylphenyl) phosphite, tri-
(2-Methoxy-4-tert-butylphenyl) phosphite, tri- (2-methyl-4-tert-butylphenyl)
Phosphite, tri- (2-nonylphenyl) phosphite, tri- (2-nonyl-6-methylphenyl)
Phosphite, tri- (2-dodecylphenyl) phosphite, trisnonylphenylphosphite, monooctyldiphenylphosphite, tri- (2-dodecyl-4-tert-butylphenyl) phosphite, didecyl-monophenylphosphite, Dioctyl-monophenylphosphite, monobutyl-diphenylphosphite, diisopropyl-monophenylphosphite, monooctyl-di- (4-tert-butylphenyl) phosphite, mono-2-methylphenyl-di- (2-
Examples thereof include cyclohexylphenyl) phosphite, di (4-tert-butylphenyl) -mono-2-nonylphenylphosphite, trilaurylphosphite and trilaurylthiophosphite. Among these phosphorous acid esters, triaryl phosphite or monoalkyl diaryl phosphite is particularly preferable.

Of course, these phosphorous acid esters may be used in combination of two or more kinds.

The amount of phosphite used is polycarbonate resin 10
0 to 0 parts by weight, usually 0.01 to 1.0 parts by weight, preferably 0.05
~ 0.2% by weight. When the amount of the phosphite used is less than the above range, the desired discoloration preventing effect cannot be obtained, and when the amount of the phosphite is more than the above range, foaming easily occurs during molding of the composition of the present invention, causing a decrease in the molecular weight of the polycarbonate resin. However, it is not preferable.

As a method for blending the phosphonium sulfonate and the phosphite ester into the polycarbonate resin, various methods can be used at any stage until just before the final molded product is molded. The simplest method is a method of dry blending the polycarbonate and the additive, but the dry blended product may be melt-mixed and extruded into pellets.

Alternatively, a master pellet prepared by kneading a predetermined amount or more of additives may be prepared and blended with a polycarbonate for dilution. When performing melt mixing extrusion, it is preferable to devise to improve the dispersion of the additives. For example, in the case of a single-screw extruder, it is preferable to use a dullage type screw or a twin-screw extruder.

In order to obtain the final molded product, the above blends or pellets may be supplied to various molding machines such as injection, extrusion, blow, compression, etc., and molded according to a conventional method. Can be done at It is preferable to maintain the resin temperature at 220 to 300 ° C. in the molding for obtaining the final molded product.

Further, the composition of the present invention includes various well-known additives other than the above-mentioned compound, for example, glass fiber, carbon fiber, reinforcing agent such as metal whiskers, carbon black, calcium carbonate, filler such as glass beads, and the like. A paraffin wax, a lubricant such as silicone oil, an antioxidant such as hindered phenol, a weather resistance-imparting agent such as triazine, a halogen-based or phosphoric acid-based flame retardant, and the like may be contained. Polymers such as polybutylene terephthalate, polyethylene terephthalate, polyethylene and polyethylene / propylene copolymer may be used in combination.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the examples, "part" means "part by weight".

The physical properties are measured as follows.

Tensile strength, elongation ・ ・ ・ Compliant with ASTM D638.

Izod impact value: According to ASTM D256.

Surface resistivity: According to ASTM D257.

Total light transmittance: According to ASTM D1003.

Yellowness: According to JIS K 7103.

Examples 1 to 9 and Comparative Example 1 100 parts by weight of a bisphenol A type polycarbonate resin having a molecular weight of 21,000 was used, and a phosphite ester and a tetrabutylphosphonium salt of dodecylsulfonic acid or tetrabutyl dodecylbenzenesulfonic acid shown in Table 1 were used. The phosphonium salt was added in the blending amount shown in Table 1, and the mixture was kneaded into pellets at 260 ° C. by a twin-screw vent extruder manufactured by Nakatani Machinery. After drying the pellets with hot air, an injection molding machine (made by Toshiba Machine
IS75S type) was used to mold a test piece at a molding temperature of 280 ° C, and the tensile strength, elongation and Izod impact value were measured.

In addition, a sheet (2 mm thick) was molded under the same conditions for 40 seconds and 120 seconds for a molding cycle, and the change in the yellow index was measured.

The same sheet made with a molding cycle of 40 seconds was used for the measurement of surface resistivity and total light transmittance. The results are shown in Table-1.

Comparative Examples 2 to 5 As a comparative example, when the polycarbonate alone and the phosphite are removed, and as the antistatic agent of the prior art,
The same measurement as that of the example was carried out except that sodium polyoxyethylene alkyl ether sulfonate (manufactured by Kao Corporation, trade name; Emal 20C) was used. The results are shown in Table-1.

[Effects of the Invention] The polycarbonate resin composition of the present invention has excellent antistatic properties and mechanical properties, and is also excellent in transparency.

Claims (2)

[Claims] 1. A compound of the general formula [I] based on 100 parts by weight of a polycarbonate resin. A polycarbonate resin composition comprising 0.1 to 20 parts by weight of a phosphonium salt of sulfonic acid and [II] 0.01 to 1.0 parts by weight of a phosphite ester. 2. The polycarbonate resin composition according to claim ¹ , wherein R ¹ in the phosphonium sulfonate salt of [I] is an aryl group having 6 to 40 carbon atoms.