JP2000302958A - Polycarbonate resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarbonate resin composition excellent in sliding properties without spoiling properties inherent in a polycarbonate resin excellent in mechanical strengths and heat resistance. SOLUTION: This polycarbonate resin composition comprises 100 pts.wt. of a polycarbonate resin (A), 0.05-10 pts.wt. of a silicon oil (B) having >=10,000 mm2/s viscosity at 25 deg.C and 0.5-30 pts.wt. of a polyorganosiloxane (C) prepared by graft-copolymerizing a (meth)acrylic acid ester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate resin composition having excellent slidability without impairing the inherent properties of the polycarbonate resin such as mechanical strength and heat resistance.

[0002]

2. Description of the Related Art In recent years, synthetic resins have been increasingly used for sliding members for the purpose of reducing the size and weight of OA equipment and electronic equipment and reducing the number of parts. It is used for parts of sliding members such as gears because of its mechanical strength. However, since the polycarbonate resin is originally a resin having poor sliding properties,
For the purpose of improvement, a sliding agent has been added.
For example, Japanese Unexamined Patent Application Publication No.
No. 136065 describes that a resin such as a fluororesin, polyolefin, polyamide, or polyester is added to a polycarbonate resin as a slidability improving material. However, when a fluorine resin is added to a polycarbonate resin, a small amount of fluorine gas is generated at the time of molding, which causes problems such as corrosion of a mold and a molding machine, and a large amount of a fluorine resin having no affinity needs to be added. Also, problems such as delamination and mold deposit during molding have occurred. Also, if you add a large amount of other thermoplastic resins such as polyolefin, polyamide, polyester,
In addition to impairing the inherent properties of polycarbonate resin such as mechanical strength, heat resistance, and flame retardancy,
Problems such as delamination also occur.

[0003] On the other hand, polycarbonate resin is chemically,
Silicone oil, which is a physically stable lubricant, is also added, but since the silicone oil on the surface of the molded product oozes out in a short time and is consumed, excellent sliding properties are initially obtained. Although it manifested, the long-term slidability was insufficient, and there were also problems such as stickiness of the surface, which was not satisfactory. In order to solve this, for example, attempts have been made to use a high molecular weight silicone oil. In this case, although the bleed out of the oil to the molded product and the long-term slidability have been improved, it is not always satisfactory. Inevitably must be added, and as a result, gloss unevenness and the like due to phase separation of the silicone oil easily occur on the surface of the molded product, which is not satisfactory in practical use. In addition, JP-A-9-255864 describes that the appearance is improved by adding another thermoplastic resin such as a polyolefin resin or a polystyrene resin to a composition comprising a polycarbonate resin and a high-viscosity silicone oil. However, the improvement effect was not enough.

[0004]

SUMMARY OF THE INVENTION Under such circumstances, the present invention has improved the slidability without deteriorating the mechanical strength and heat resistance inherent to the polycarbonate resin, and has excellent molded article appearance. An object of the present invention is to provide a polycarbonate resin composition.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, obtained by graft copolymerizing a high-viscosity silicone oil and a (meth) acrylate ester on a polycarbonate resin. The resin composition obtained by adding the polyorganosiloxane is mechanical strength,
The inventors have found that they have excellent heat resistance and slidability, and have reached the present invention. That is, the present invention has a viscosity at 25 ° C. of 10, 10 parts by weight based on 100 parts by weight of the polycarbonate resin (A).
000 mm ² / s or more of silicone oil (B) 0.0
Polyorganosiloxane (C) obtained by graft copolymerizing 5 to 10 parts by weight and (meth) acrylic acid ester
An object of the present invention is to provide a polycarbonate resin composition containing 0.5 to 30 parts by weight.

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, aromatic polycarbonate, aliphatic polycarbonate and aromatic-aliphatic polycarbonate can be used as the polycarbonate resin (A), but aromatic polycarbonate is preferred. As the aromatic polycarbonate resin in the present invention, an aromatic dihydroxy compound or a thermoplastic aromatic polycarbonate polymer which may be produced by reacting a small amount of the polyhydroxy compound with phosgene or a carbonic acid diester may be used. Or it is a copolymer. The production method is not particularly limited, and it can be produced by a phosgene method (interfacial polymerization method) or a melting method (ester exchange method). Further, an aromatic polycarbonate resin produced by a melting method and having an adjusted amount of terminal OH groups can also be used. As the aromatic dihydroxy compound, 2,2-bis (4-
Hydroxyphenyl) propane (= bisphenol A), tetramethylbisphenol A, bis (4-hydroxyphenyl) -P-diisopropylidenebenzene, hydroquinone, resorcinol, 4,4-dihydroxydiphenyl, etc., and preferably bisphenol A Is mentioned. Further, a compound in which one or more tetraalkylphosphonium sulfonates are bonded to the aromatic dihydroxy compound for the purpose of further increasing the flame retardancy,
And / or a polymer or oligomer having a phenolic OH group at both ends and having a siloxane structure can be used.

To obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-dimethyl-2,4,4
6-tri (4-hydroxyphenyl) heptene-2,
4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptane, 2,6-dimethyl-2,4,6-
Tri (4-hydroxyphenyl) heptene-3,1,
3,5-tri (4-hydroxyphenyl) benzol,
1,1,1-tri (4-hydroxyphenyl) ethane,
2,6-bis (2-hydroxy-5-methylbenzyl)
-4-methylphenol, α, α ′, α ″ -tri (4-
Polyhydroxy compounds such as (hydroxyphenyl) -1,3,5-triisopropylbenzene, 3,3-bis (4-hydroxyphenyl) oxindole (= isatin bisphenol), 5-chlorisatin bisphenol, , 7-Dichloroisatin bisphenol, 5-bromoisatin bisphenol, etc. may be used as a part of the aromatic dihydroxy compound.
0 mol%, preferably 0.1 to 2 mol%.
In order to control the molecular weight, a monovalent aromatic hydroxy compound may be used, and examples thereof include m- and p-methylphenol, m- and p-propylphenol, p-tert-butylphenol, and p-long-chain alkyl-substituted phenol. Can be As the aromatic polycarbonate resin, preferably, a polycarbonate resin derived from bisphenol A as an aromatic dihydroxy compound, or a polycarbonate copolymer derived from bisphenol A and another aromatic dihydroxy compound is preferably used. Further, a polymer or oligomer having a siloxane structure can be copolymerized for the purpose of enhancing flame retardancy. As the aromatic polycarbonate resin, a mixture of two or more resins may be used.

[0008] The molecular weight of the aromatic polycarbonate resin is
Methylene chloride was used as a solvent, and the viscosity average molecular weight was 1 based on the solution viscosity measured at a temperature of 25 ° C.
6,000 to 30,000. More preferably 1
7,000-25,000, most preferably 1
8,000-23,000. Viscosity average molecular weight of 1
If it is less than 6,000, the mechanical strength is insufficient, and
Exceeding the range is not preferred because the appearance of the molded article tends to be poor. The silicone oil (B) used in the present invention is:
It is a silicone oil having a viscosity at 25 ° C. of 10,000 mm ² / s or more, and can be arbitrarily selected from commonly known ones. For example, those composed of polydimethylsiloxane, silicone oil in which some or all of the methyl groups of polydimethylsiloxane are substituted with phenyl groups, hydrogen, alkyl groups having 2 or more carbon atoms, halogenated phenyl groups, fluoroester groups, epoxy Epoxy-modified silicone oil having a group, amino-modified silicone oil having an amino group, alcohol-modified silicone oil having an alcoholic hydroxyl group, polyether-modified silicone oil having a polyether structure, and the like,
These may be used alone or in combination of two or more.
The viscosity of the silicone oil at 25 ° C. is preferably 10
0.00000 mm ² / s or more, more preferably 500,0
00 mm ² / s or more, particularly preferably
It is not less than 000 mm ² / s. If the viscosity of the silicone oil is less than 10,000 mm ² / s, the long-term slidability is unsatisfactory. The polyorganosiloxane (C) obtained by graft copolymerization of a (meth) acrylate used in the present invention is obtained by graft copolymerization of a (meth) acrylate with a polyorganosiloxane represented by the following general formula (1). What is done.

[0009]

Embedded image

[Wherein R1, R2 and R3 independently represent an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group;
A monovalent hydrocarbon group having 1 to 20 carbon atoms, such as an aryl group such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group, or at least one hydrogen atom bonded to a carbon atom of these groups is halogen. Represents a group substituted with an atom. Y represents a radical reactive group exemplified by a vinyl group, an allyl group, a γ-methacryloxypropyl group, or an —SH group-containing organic group exemplified by a γ-mercaptopropyl group. Z1,
Z2 is independently a hydrogen atom, a lower alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, or -SiR4R5
R6 (R4 and R5 each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms as exemplified by R1 to R3; ~ 20
A monovalent hydrocarbon group, a monovalent halogenated hydrocarbon group having 1 to 20 carbon atoms, or an organic group having a radical reactive group exemplified by Y or a —SH group. ) Represents a triorganosilyl group. m represents a positive integer of 10,000 or less, and n represents an integer of 1 or more. In one molecule, each of R1 to R6 and Y may be the same or different. Such a polyorganosiloxane can be produced by a known method. For example, it can be produced by using a chain or cyclic low-molecular-weight polyorganosiloxane or alkoxysilane having the above-mentioned group and combining means of hydrolysis, polymerization and equilibration. Hydrolysis, polymerization, and equilibration can be performed by a known technique even in a state of being dispersed in water. (Meth) acrylic acid ester is an alkyl of (meth) acrylic acid such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, 2-ethylhexyl, lauryl and stearyl. Esters, methoxyethyl, alkoxyalkyl esters such as butoxyethyl, cycloalkyl esters such as cyclohexyl,
Aryl esters such as phenyl are exemplified, and one or more of them can be used in combination.

In the present invention, the (meth) acrylic acid ester can be used in admixture with one or more other vinyl monomers copolymerizable therewith. These other copolymerizable vinyl monomers are 30% by weight based on the total amount of (meth) acrylic acid esters as 100% by weight.
The following is preferred. The graft copolymerization can be performed by a known technique. For example, graft copolymerization can be performed by emulsifying and dispersing a mixture of a polyorganosiloxane and a (meth) acrylate ester or another vinyl monomer in water and polymerizing the mixture in the presence of a radical polymerization initiator. Emulsifiers and radical polymerization initiators used in this method may be those known for emulsion polymerization. After completion of the polymerization, a graft copolymer can be obtained by salting out, filtration, washing with water and drying. In this emulsion graft copolymerization, if the polyorganosiloxane is produced in a state of being dispersed in water as described above, the resulting emulsion of the polyorganosiloxane can be directly used as a raw material for graft copolymerization. In the present invention, the weight ratio of (meth) acrylate to polyorganosiloxane is 90:
The graft copolymerization is preferably performed at 10 to 20:80, more preferably 85:15 to 30:70, and particularly preferably 80:20 to 40:60. At this weight ratio, if the (meth) acrylate is less than 10, the compatibility with the polycarbonate is insufficient, and the mechanical strength and appearance of the molded product are difficult. If the (meth) acrylate exceeds 80, the (meth) acrylic ester exceeds 80. And the sliding property is insufficient.

The polyorganosiloxane obtained by graft-copolymerizing the (meth) acrylic ester is sold, for example, under the trade name of "Charine" by Nissin Chemical Co., Ltd., and can be easily obtained from the market. Can also. The polycarbonate resin composition of the present invention may further contain additives such as ultraviolet absorbers, stabilizers such as antioxidants, pigments, dyes, lubricants, flame retardants, release agents, glass fibers, and glass flakes, if necessary. A reinforcing material such as carbon fiber or a whisker such as potassium titanate or aluminum borate, or a resin other than a polycarbonate resin can be added and blended. Examples of the resin other than the polycarbonate resin include polyester resins such as polybutylene terephthalate and polyethylene terephthalate, polyamide resins, styrene resins such as high impact polystyrene (HIPS) resins or ABS resins, and thermoplastic resins such as polyolefin resins. The compounding amount of the resin other than the polycarbonate resin is preferably 40% by weight or less, more preferably 30% by weight or less of the total amount of the polycarbonate resin and the resin other than the polycarbonate resin. In the polycarbonate resin composition of the present invention described in detail above, the composition ratio of the polycarbonate resin (A), the silicone oil (B), and the polyorganosiloxane (C) obtained by graft-copolymerizing the (meth) acrylate ester is as follows. When A) is 100 parts by weight, the silicone oil (B) is 0.05 to 10 parts by weight, preferably 0.1 to 10 parts by weight.
4 parts by weight, particularly preferably 0.2 to 3 parts by weight, and the polyorganosiloxane (C) is 0.5 to 5 parts by weight.
The amount is 30 parts by weight, preferably 1 to 20 parts by weight, particularly preferably 1 to 15 parts by weight.

When the proportion of the polycarbonate resin (A) is small, the mechanical strength, heat resistance and appearance of the molded product are unsatisfactory, and when it is too large, the slidability is insufficient. When the proportion of the silicone oil (B) is less than 0.05 part by weight, the slidability is unsatisfactory, and when it exceeds 10 parts by weight, the appearance of the molded product is unsatisfactory. If the proportion of the polyorganosiloxane (C) obtained by graft-copolymerizing the (meth) acrylic ester is less than 0.5 part by weight, the effect of improving the slidability is unsatisfactory. The strength decreases, which is not preferable. Also, silicone oil (B),
The mixing ratio of the polyorganosiloxane (C) obtained by graft-copolymerizing the (meth) acrylic ester was also 5: 1 by weight.
１ ： 1: 50, more preferably 2: 1:
1 to 1:30. , Silicone oil (B),
If the compounding ratio of the polyorganosiloxane (C) obtained by graft-copolymerizing the (meth) acrylic ester exceeds this range, the mechanical strength and the appearance of the molded product are undesirably reduced. As a method for obtaining the polycarbonate resin composition of the present invention, various kneaders, for example, uniaxial and multiaxial kneaders,
After kneading the above components with a Banbury mixer, roll, Brabender plastograph, or the like, a method of cooling and solidifying or a suitable solvent such as hexane, heptane, benzene,
A solution mixing method is used in which the above components are added to hydrocarbons such as toluene and xylene and derivatives thereof, and the dissolved components are mixed together, or the dissolved and insoluble components are mixed in a suspended state. The melt-kneading method is preferred from the industrial cost, but is not limited thereto. The method for molding the polycarbonate resin composition of the present invention is not particularly limited, and molding methods generally used for thermoplastic resin compositions, for example, injection molding, hollow molding, extrusion molding, sheet molding, thermoforming, Molding methods such as rotational molding and lamination molding can be applied.

[0014]

EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples.
Although described in detail, the present invention is not limited to these ranges. In this example and the comparative example,
The following were used as each component. (A) Polycarbonate resin: poly-4,4-isopropylidene diphenyl carbonate Trade name: Iupilon S-3000, manufactured by Mitsubishi Engineering-Plastics Corporation, viscosity average molecular weight 2
1,000 (hereinafter sometimes referred to as "PC") (B) Silicone oil: B-1 Polydimethylsiloxane Trade name: VRS-0
1. Shin-Etsu Silicone Co., Ltd., viscosity at 25 ° C: 6,
1,000,000 mm ² / s B-2 polydimethylsiloxane Trade name: KF-9
6. Shin-Etsu Silicone Co., Ltd., viscosity at 25 ° C: 50
0 mm ² / s (C) Polyorganosiloxane graft-copolymerized with methacrylic acid ester Polydimethylsiloxane graft-copolymerized with methyl methacrylate Product name: Charine R170, a product of Nissin Chemical Co., Ltd. Polydimethylsiloxane content: 70% by weight

[Examples 1 to 4 and Comparative Examples 1 to 5] Compositions having the components and compositions shown in Table 1 wherein the weight ratio of polycarbonate to silicone oil was 90:10 were uniformly mixed by a mixer. Thereafter, using a twin-screw extruder (manufactured by Nippon Steel Works), pelletization was performed at a cylinder temperature of 280 ° C. and a screw rotation speed of 250 rpm. Subsequently, after uniformly mixing the pellets and the remaining components with a mixer so as to have a predetermined ratio, a twin-screw extruder (a product of Nippon Steel Works)
And pelletized at a cylinder temperature of 280 ° C. and a screw rotation speed of 250 rpm. Next, this resin composition was injected into an injection molding machine (product of Japan Steel Works, clamping force: 50T).
And injection molding was performed under the conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. to produce a molded product, which was evaluated by the following method. (Evaluation method) (1) Izod impact test A notched Izod impact test was performed according to ASTM D256. (2) Flexural Modulus A three-point bending test was performed according to a bending test method according to ASTM D790.

(3) Heat deformation temperature According to ASTM D648, under the condition of 1.82 MPa,
A load deflection test was performed. (4) Cyclic bending fatigue According to ASTM D671, a test was performed using a Type A test piece at 23 ° C. and an actual stress of 19 MPa, and the number of times of destruction was evaluated. (5) Slidability According to JIS K7218 A method, S45
Using a C ring, load 5kg (contact pressure 2.5kg / c
m ² ), a sliding test was performed under the conditions of a peripheral speed of 10 cm / sec and a running time of 10 hours, and a specific wear amount was calculated from the wear amount by the following equation. Specific wear (mm ³ / kg · km) = wear (g) / density (g / mm ³ ) / load
(kg) / Running distance (km) (6) Appearance of molded article The appearance of a test piece used for the repeated bending fatigue test was visually observed and evaluated according to the following steps. ：: good △: slightly poor ×: bad

[0017]

[Table 1]

[0018]

The polycarbonate resin composition of the present invention has excellent mechanical strength and heat resistance, which are the characteristics of the polycarbonate resin, and has improved slidability, which has been regarded as low, so that it is particularly suitable for gears. It is useful for various sliding applications such as, and its industrial utility is large, and it is useful in many fields such as electric and electronic fields and parts for OA equipment.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoto Obayashi 5-6-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Inside the Technology Center of Mitsubishi Engineering-Plastics Corporation (72) Takashi Miyajima 5-chome, Higashi-Yawata, Hiratsuka-shi, Kanagawa No. 6-2 Mitsubishi Engineering Plastics Co., Ltd. Technology Center F term (reference) 4J002 BN173 CG001 CP032 GM00

Claims (6)

[Claims] 1. A viscosity at 25 ° C. of 10,000 mm ² / s with respect to 100 parts by weight of a polycarbonate resin (A).
0.05 to 10 parts by weight of the above silicone oil (B),
And a polyorganosiloxane (C) obtained by graft copolymerization of (meth) acrylic acid ester and 0.5 to 30 parts by weight of a polycarbonate resin composition. 2. Viscosity of silicone oil (B) at 25 ° C.
Is 100,000mm ^Two/ S or more
The polycarbonate resin composition according to claim 1. 3. The polycarbonate resin composition according to claim 1, wherein the viscosity of the silicone oil (B) at 25 ° C. is 1,000,000 mm ² / s or more. 4. The polycarbonate resin composition according to claim 1, wherein the viscosity average molecular weight of the polycarbonate resin (A) is from 16,000 to 30,000. 5. A polyorganosiloxane (C) obtained by graft copolymerization of a (meth) acrylic acid ester, wherein the (meth) acrylic acid ester is grafted to the polyorganosiloxane at a weight ratio of 90:10 to 20:80. 5. The copolymer according to claim 1, wherein the copolymer is copolymerized.
The polycarbonate resin composition according to any one of the above. 6. The weight ratio of the silicone oil (B) and the polyorganosiloxane (C) obtained by graft copolymerizing the (meth) acrylate is 5: 1 to 1:50.
The polycarbonate resin composition according to any one of claims 1 to 5, wherein