JPS58167693A - Organopolysiloxane lubricant - Google Patents

Abstract

PURPOSE:An organopolysiloxane lubricant that contains an organopolysiloxane having a plurality of functional groups, thus being suitable for use in giving durable lubricity and releasability to synthetic resins and rubbers. CONSTITUTION:The objective lubricant contains, as the major component, an organopolysiloxane having 1 or more of 2 different kinds of functional groups selected from 4 different groups of -R<1>-COOH, -R<2>-SH and -R3-OY and -R<4>-X R<1>, R<2>, R<3>, R<4> are divalent organic group; Y is H, monovalent organic group; X is -CH2Cl, -(CF2)n-A (A is H, F; n is 1-8) , all of which bond to Si atoms in a molecule. The resultant lubricant is used usually by 0.05-20pts.wt. per 100pts.wt. of the synthetic resin or rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an organopolysiloxane lubricant, which is particularly useful for imparting durable and excellent lubricity or mold release properties to synthetic resins or synthetic rubbers. This invention relates to organopolysiloxane lubricants.

Conventional 9 synthetic resins and synthetic rubbers have been used in a wide range of applications such as molded products, cast products, laminates, films, fibers, foams, adhesives, and paints. Because the properties of the product require lubricity or mold releasability.

Attempts have been made to improve its properties by adding additives such as silicone oil, wax, higher alcohols, and metallic soaps. In particular, the addition of silicone oil significantly improves lubricity and mold release properties, but it lacks compatibility with the resin, so the silicone oil separates from the resin and oozes out, causing various problems. ing. In order to improve this problem, for example, Japanese Patent Application Laid-open No. 121344/1983 is a mixture of thermoplastic resin silicone oil and silicone rubber, but it is not possible to sufficiently prevent the silicone oil from seeping out, and it is a problem. There is a drawback that the inherent properties of the thermoplastic resin change when silicone rubber is blended. Furthermore, Japanese Patent Publication No. 52-6751 discloses a compound containing an organopolysiloxane having a 10COR' group (R' is a substituted or unsubstituted monovalent hydrocarbon group) directly bonded to a silicon atom in a vinyl chloride resin. In Although.

-〇COR' group is directly bonded to silicon atom.

It has the disadvantage that it is easily hydrolyzed and gels due to moisture in the air, which significantly impairs the lubricity and appearance of the resin.

In Japanese Patent Application Laid-Open No. 56-412'56, it is used as a modifier for synthetic resins in one molecule.

Bonds to silicon atoms. -CH2Cl group Y group, (Y is -
CF3 group or +CF20F2-+kW (W represents a hydrogen atom or a fluorine atom, is an integer from 1 to 4)] and -
An organopolysiloxane having a 0COR' group (R' is a monovalent hydrocarbon group having 7 to 21 carbon atoms) is disclosed, but as described above, the -0COR group is directly bonded to a silicon atom. However, it has the disadvantage that it absorbs moisture and decomposes, causing its properties to change over time.

The present inventors have conducted extensive research on organopolysiloxane lubricants, especially lubricants for synthetic resins and synthetic rubbers that do not have the above-mentioned drawbacks. By blending an organopolysiloxane having a specific functional group that easily binds to the additives to be used and imparts compatibility, the organopolysiloxane does not ooze out and is durable. It was discovered that excellent lubricity and mold release properties can be imparted9.
We have arrived at the present invention.

In other words, nine of the present invention are bonded to silicon atoms in one molecule. -R'' C0OH group, -R2-8H group, R3-
〇Y group and -R'-X group [here + R' + R2
+ R3 and R4 are divalent organic groups, Y is a hydrogen atom or a monovalent hydrocarbon group, X is -CI (2Cl group or +CF
2−+nA group (where A is a hydrogen atom or a fluorine atom, and n is a positive integer from 1 to 8). The present invention relates to an organopolysiloxane lubricant having as a main ingredient an organopolysiloxane having at least one functional group of two types arbitrarily selected from among the four types of functional groups shown below.

41 The organopolysiloxane used as the lubricant of the present invention can have a linear, 9-branched, or networked molecular shape, but is preferably a linear one,
Bonds to silicon atoms. -R'-COOH group, -R
2-8H group, -R3-OY group (Y is hydrogen atom size or 1
valent hydrocarbon group) and -R4-X group (X is CH2Cl group or +CF, -+nA group, A is hydrogen atom or fluorine atom, n is an integer from 1 to 8) It has at least one functional group of two types. Therefore, -R'-COOH group and -
R2-8H group, -R'-COOH group and -R''-OY group,
-R'-COOH group and -R''X group, -R2-8R group and -R3-OY group + R2-8H group and -R'-X group,
and l There are six types of combinations of -R3-OY and -R4-X groups0 Here, as the divalent organic group represented by R1゜R2, R3 and R4, 9For example, methylene group, ethylene group , alkylene groups such as propylene groups and butylene groups, phenylene groups, alkylenearylene groups, -(
-CH2CH3 I C ding■20+-l! , +CH2CHO+m, (however,
(l and m are integers of 1 to 50) are exemplified by oxyalgylene groups and polyoxyalkylene groups, but 1
It includes divalent organic groups consisting of a combination of two or more of the exemplified organic groups. The two types of divalent organic groups selected from R', R2+, R3 and R4 bonded to the silicon atom in one molecule may be the same or different. Among the divalent organic groups, preferably ethylene group,
They are a propylene group and a polyoxyalkylene group. In the case of a polyoxyalkylene group, if the molecular chain becomes too long, the activity of the functional group bonded to the end of the group will weaken, reducing the bonding strength with the synthetic resin, the synthetic rubber, or the various additives blended with it. -'i or m is preferably in the range of 1 to 10. Y in the R3-0Y group is a hydrogen atom or a monovalent hydrocarbon group, and examples of the monovalent hydrocarbon group include a methyl group, an ethyl group, and a propyl group.

Dotesyl group, cyclohexyl group, phenyl group.

β-phenylethyl radical is exemplified. Among these, hydrogen atoms are preferred.

It bonds to the silicon atom of this organopolysiloxane.

The positions where the two different types of functional groups are present are not particularly limited, and they may be present only at the end of the molecular chain of organopolysiloxane, or only within one molecular chain, and may be present in a twisted molecular chain. It may exist both at the terminal and in the molecular chain.

Other organic groups that bond to the silicon atom in one molecule include methyl, methyl, and phenyl groups. This is the case.

The siloxane level number (degree of polymerization) of the organopolysiloxane used is in the range of 5 to 1,000.

If it is smaller than this range, the lubricity or mold release properties will deteriorate, and if it is thicker than this range, the viscosity will be too high and it will be difficult to handle. In terms of lubricity, mold releasability, and handling, the number of siloxane units is preferably in the range of 20 to 400. The ratio of the total number of two types of functional groups to the total number of siloxane units contained in one molecule is 100:2 to 1.
The range is preferably 00:50.

When used for a particularly preferred synthetic resin or synthetic rubber as a target for imparting lubricity or mold release properties, the amount used is 9. The type of synthetic resin or synthetic rubber, the type of organopolysiloxane and the density of its functional group, Although it is not limited as it varies depending on the purpose of lubricity or mold release, etc.9 Usually, it is based on 100 parts by weight of synthetic resin or synthetic rubber.

Organopolysiloxane 005-20 needle part.

It is preferably used in an amount of 0.5 to 10 parts by weight.

If the amount is less than 0.005 parts by weight, the effect of lubricity or mold releasability will be small, and if it is more than 20 parts by weight, it will not only be economically disadvantageous but also affect the inherent properties of the 1 synthetic resin or synthetic rubber.

The organopolysiloxane of the present invention can be used in the form of liquid, solution, emulsion, or paste, and may be added or blended into the object to impart lubricity or mold release properties.
Alternatively, it may be applied or impregnated. In short, any method that can impart lubricity or mold releasability to the object can be used.

An example of the method for producing the organopolysiloxane of the present invention is to use the addition reaction described in Publication No. 9969 in 1999, which basically produces organohydrodiene polysiloxane. and CH2= CH
COOH, CH2=CHC1 (2SH.

Two glazes of the functional group-containing unsaturated compounds represented by CH2-CHCH20H and CH2=CHCF3 can be easily obtained by addition-reacting them simultaneously or separately in the presence of a platinum-based catalyst.

Suitable objects that impart lubricity or mold release properties are conventionally known synthetic resins or synthetic rubbers.

Naturally, synthetic resins include thermoplastic resins and thermosetting resins. Examples of these synthetic resins and synthetic rubbers include polyvinyl chloride.

Polyvinyl acetate, polyethylene, polypropylene, polyamide, polyester, polyurethane.

Polyacrylonitrile, polyvinylidene chloride.

Polystyrene, polycarbonate, polypynyl fluoride, polyacrylic ester, polymethacrylic ester, polyvinyl alcohol, polyvinyl acetal, polyvinyl formal, epoxy resin, silicone resin, alkyd resin.

Melamine resin, cellulose resin, phenolic resin, vinyl chloride-vinylidene chloride copolymer, cyclized vinyl-methyl acrylate copolymer, vinyl chloride-methyl methacrylate copolymer, vinyl chloride-acrylonitrile copolymer, vinyl chloride- Styrene copolymer, vinyl chloride-ethylene copolymer, styrene-acrylonitrile copolymer.

methacrylic ester-acrylic ester copolymer,
Acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, vinyl acetate-vinyl chloride copolymer.

Vinyl acetate-ethylene copolymer, vinyl acetate-acrylic acid copolymer, vinyl acetate-acrylonitrile copolymer,
Vinyl acetate acrylate copolymer, vinyl acetate
Malenic acid copolymer.

Vinyl acetate-styrene copolymer, vinyl acetate-polyvinyl alcohol copolymer, vinyl acetate-vinyl chloride-polyvinyl alcohol copolymer, vinyl acetate-vinyl chloride-
Ethylene copolymer, imprene rubber, chloroprene rubber, fluororubber, polyurethane rubber, polyether rubber, ethylene-propylene rubber.

Examples include ethylene-propylene-diene rubber, butyl rubber, acrylic rubber, and acrylonitrile-butadiene rubber. 6. Although natural rubber does not normally contain cavities in synthetic rubber, its molecular structure is similar to that of impregnated rubber. The synthetic rubber mentioned above shall include natural rubber. Two or more of the exemplified synthetic resins and synthetic rubbers may be used as a mixture. Of these, particularly preferred are synthetic resins such as vinyl chloride resins, vinyl acetate resins, polyurethane resins, and epoxy resins. 9 synthetic rubber is an ethylene-propylene-diene-based rubber. The term "system" as used herein is meant to include all copolymers or mixtures containing it.

The form of synthetic resin or synthetic rubber is liquid or solution.

emulsion, paste, latex, powder.

11- It can be used in any solid state. and.

For example, molded products, cast products, laminates, and films.

It can take the form of fiber, adhesive, foam, paint, etc. depending on the purpose.

When the organopolysiloxane of the present invention and either or both of the synthetic resin and the synthetic rubber are used as a solution, an organic solvent may be used, and when the organopolysiloxane of the present invention is used as an emulsion, a surfactant may be used. . I cut it.

For example, various conventionally known additives may be added to either or both of them.

Dry process silica, wet process silica, magnesium silicate, aluminum silicate, calcium carbonate.

Clay, mica, talc, titanium oxide, aluminum oxide, magnesium oxide, red iron oxide, magnetism, iron oxide, various metal powders, carbon blank.

Silicone oil, silane coupling agent, rosin, incyanates, wax, higher alcohol-12-alcohol, organic tin fatty acid salt, plasticizer, stabilizer, flame retardant, ultraviolet absorber, lubricant, antistatic agent, antioxidant , fungicide 1
Foaming agent 9 A coloring agent, an adhesion promoter, etc. can be blended.

The organopolysiloxane of the present invention can be suitably used as a material for imparting lubricity or mold release properties in all applications of synthetic resins or synthetic rubbers. For example, molded products, cast products, laminates, films, and fibers.

These include foams, adhesives, and paints. This organopolysiloxane is mixed with the functional groups of the organopolysiloxane by adding, blending, coating, impregnating, dipping, etc. to the synthetic resin or synthetic rubber. Since it has a strong affinity with additives, it can provide durable and excellent lubricity or mold release properties. For example, when added to a molded product, it has the effect of an internal lubricant or an internal mold release agent, and when applied to the surface of a molded product or the inner surface of a molding die, it acts as an internal lubricant or internal mold release agent. It is possible to impart lubricity or mold releasability to the surface. Similarly, when a resin plate is made into a film, it has non-blocking properties, and when added to paint or applied to the surface of the film, a cured film with excellent lubricity, water repellency, and gloss can be obtained. . The use of the organopolysiloxane lubricant of the present invention is not limited, but some specific examples of use in 9% are magnetic tapes, magnetic toners, and magnetic cards.

By adding synthetic resin or synthetic rubber to magnetic disks, audio disks, and other materials that use synthetic resin or synthetic rubber as a binder or base material, durable and excellent lubricity can be imparted. Also, by adding it to polyurethane resins used as materials for automobile bumpers, it has an excellent effect as an internal mold release agent or internal lubricant during injection molding, and similarly, it can be added to epoxy resin compositions for molding. As a result, it exhibits excellent mold releasability without mold contamination during molding.

In addition, automotive mat guards, banking, gaskets, and food packaging films that require lubricity or mold release properties.

It is useful as a film for agricultural vinyl houses, a synthetic resin bearing for medical equipment 1, and a lubricant for textiles.

The organopolysiloxane lubricant of the present invention can be used as a lubricant for machines and equipment in the form of oil or compound in addition to imparting lubricity or mold release properties to synthetic resins or synthetic rubbers. shows. Parts and articles in the examples refer to parts by weight and parts by weight, and viscosity is a value measured at 25°C.

Example 1 Polyvinyl chloride (P-455 manufactured by Mitsubishi Monsando).

Vinyl chloride-vinyl acetate copolymer (Denkabinyl M M-90 manufactured by Denki Kagaku Co., Ltd., vinyl acetate content 10%),
Ethylene-vinyl acetate copolymer (Ultra Seven 680 manufactured by Toyo Soda), polyethylene (Milan 24 H manufactured by Mitsui Polychemicals), polypropylene (Noprene H'5Q1 manufactured by Sumitomo Chemical).

Polymethyl methacrylate (Sumipe, Kusu 1 manufactured by Sumitomo Chemical Co., Ltd.)
5-LG), polyamide (6 nylon for fiber manufactured by Toshisha Co., Ltd.)
.

7th formula for 100 parts of each resin of polyester (polyethylene terephthalate for fibers manufactured by Toshisha Co., Ltd.).

Viscosity: 310 centistokes.

1 COOT(SH Viscosity 300 centistokes.

Viscosity: 98 centistokes.

16- l CH2Cl SH Viscosity 350 centistokes.

Viscosity 450 centistokes.

Viscosity 180 centistokes.

A film having a thickness of 1.5 mm was prepared by adding 15 parts of each of the organopolysiloxanes represented by the following formulas. For each film, the seepage into the organopolysiloxane film before heating and after heating at 70°C (7) for 5 days was observed with the naked eye and judged on a four-level scale. .

◎ There is no strong seepage to the film surface. ○ Almost no seepage onto the film surface.

△ Slight seepage onto the film surface.

× Significant seepage onto the film surface.

As a comparative example, an experiment similar to the above was conducted using a 300 centistoke dimethylpolysiloxane with both ends of its molecular chain endblocked with trimethylsilyl groups. These results are shown in Table 1.

The film to which the organopolysiloxane of the present invention was added did not bleed onto the film surface and was extremely superior to the film to which dimethylpolysiloxane was added as a comparative example. It was observed that the organopolysilos and xane of the present invention tended to have better affinity and compatibility with vinyl chloride resins and vinyl acetate resins. from this result.

Vinyl chloride resin9. Fields that require vinyl acetate resin to have lubricating properties, especially magnetic hoops,
It is expected to be effective in applications such as magnetic recording media such as magnetic disks, vinyl film for agricultural use, and medical equipment.

Table 1 Example 2 100 parts of polyether polyol (OH value 28.2), 17 parts of ethylene glycol, 1.2 parts of a 33-dipropylene glycol solution of triethylene diamine, and dibutyltin were added to four 11 paper cups. Dilaurate 00
Take 8 parts, add 2 parts each of the organopolysiloxanes (A), Q3), (C) and q) used in Example 1, and stir evenly for 10 seconds at a stirring speed of 1500 rpm. , 107 parts of crude methylene diisocyanate (incyanate 26%) was added, and the mixture was heated again at 1500 rpm.
The mixture was stirred for 10 seconds at m. This mixture is 30 x 30
Pour into a 0.5 cm x 0.5 cm mold (lined with 30 μm thick clean aluminum foil on the inside and preheated to 70°C), heat for 3 minutes at <70"C, and then heat to 120" C. It was heated and cured at 0.degree. C. for 60 minutes.After cooling, it was taken out from the mold and cut into pieces of 3 CTn in width.The releasability between the aluminum foil and the polyurethane resin was examined, and the effect as an internal mold release agent was examined.

After the peeling test, the film was further heated in the open at 60°C for 2 days, and then a line was drawn with oil-based marker ink on the surface of the polyurethane resin that had been in contact with the aluminum foil to examine the taintability. Peelability and vain tupleability were evaluated in the following three stages.

[Releasability]

Grade 1: Very easy to peel.

Grade 2: Peeling is somewhat heavy.

Grade 3: Peeling is very heavy or difficult.

[Bain tupleness]

Grade 1: The magic ink does not fade and the ink comes out evenly.

Grade 2: There is some misalignment of the magic ink.

Grade 3: Magic ink becomes dotted and not uniform.

The results are shown in Table 2.

As a comparative example, instead of the organopolysiloxane of the present invention, 500 centistoke dimethylborine loxane with trimethylsilyl groups endblocked at both ends of the molecular chain, methylphenylpolysiloxane endblocked with trimethylsilyl groups at both ends of the molecular chain of 500 centistokes, and polyurethane. The peelability and taintability of the molded products were examined under the same conditions as above, except that 2 parts each of a 500 centistoke dimethylborisyrogylene/polyoxyalkylene combination, which is used as a foam stabilizer, was added. . The results are shown in Table 2. All products using the organopolysiloxane of the present invention have good releasability, that is, internal mold releasability, and also have good taintability because they do not bleed to the surface even when heated. Met. This result shows that it is useful as an internal mold release agent in the production of automobile bumpers, which are polyurethane resin molded products, and it is also useful as a mold release agent when coating products with polyurethane resin and applying embossing. It shows that there is. moreover.

When a polyurethane resin is used as a binder for magnetic tape, it is presumed that it is also suitable for adding lubricity to the binder.

23- Table 2 Example 3 Epoxy equivalent weight 220. 75 parts of cresol novolak epoxy resin with a softening point of 80°C, 25 parts of brominated bisphenol A type epoxy resin with an epoxy equivalent of 400, a softening point of 70°C, and a bromine content of 45% by weight, a softening point of 90° as a hardening agent.
C phenol novolac resin 24-50 parts of fat, 420 parts of fused silica powder as an inorganic filler, 1 part of 2-methyl-4-imidazole as a hardening accelerator, 2 parts of carbon black as a pigment, 20 parts of antimony trioxide, internal dispersion Two parts of the organopolysiloxane powder used in Example 1 was added as a molding agent, and the mixture was kneaded with heated rolls at 80 to 90°C.

After cooling, it was pulverized to obtain an epoxy resin composition for molding. This composition is molded and mold releasability.

Mold stains, imprintability, and adhesion were evaluated. Subsequently, organopolysiloxane (B) used in Example 1
, (C) and [F] were molded under the same conditions as above except that 2 parts each were added.

A similar evaluation was conducted. The results are shown in Table 3. As a comparative example, instead of the above organopolysiloxane,
Two parts of carnauba wax and two parts of dimethylpolysiloxane having a viscosity of 1000 centistokes and having trimethylsilyl groups capped at both ends of the molecular chain were also molded under the same conditions and evaluated in the same manner.

The evaluation method was as follows.

[Mold releasability]

A mold with a cylindrical cavity with a cross-sectional area of 1 crI, 1
5 g of each composition was compression molded at 175°C for 2 minutes, and the extrusion force (kg) released from the mold immediately after molding was measured using a push-pull gauge. This was repeated 10 times and the lowest and highest values were taken.

[Mold dirt]

Use a mold for 20 To-202 transistors.

Transfer molding was performed continuously at 175° for 2 minutes 500 times, and stains on the mold after molding were visually observed. If there is no clouding at all on the steel surface of the mold, it is considered "none".

Items with cloudy appearance were judged as [Yes, J].

[Imprintability]

To-202) 2791220-piece mold was used.

On the molded surface, which was transfer molded at 175°C for 2 minutes,
Marked with Markem 7261 ink and heated to 150°C.
After curing the ink for a period of time, a cellophane tape was brought into close contact with the surface of the ink, and when the tape was rapidly peeled off, the transferability of the ink to the tape side was visually judged. Repeat this 10 times. If there is no transfer at all to the tape side in all 10 times, mark ○, if there is at least one transfer to the tape side, mark Δ, and if it is transferred to the entire surface of the tape, mark once. The above items were marked with an X.

[Adhesion]

To-202) 2791220 molds were used.

The semiconductor was sealed by molding the transformer at 175°C for 2 minutes. Immerse 10 of each molded product in Red Check liquid, boil it for 12 hours, take it out, and check the degree of penetration of Red Check liquid into the interface between the molded product and the lead frame using a microscope. , Those in which even a slight amount of infiltration was observed in all 10 pieces were marked with an x mark.

27-Table 3 As is clear from Table 3, the mold releasability is extremely superior compared to the comparative example using a conventional internal mold release agent such as carnauba wax.

It does not stain molds and has excellent marking properties and adhesion to semiconductor components, so it is suitable for semiconductor sealing materials etc. whose main material is epoxy resin.

Example 4 EP-43 (Ethylene Glopyre 28 manufactured by Japan Synthetic Rubber Co., Ltd.
~ Interpolymer), 48 parts of Nibsil VN-3 (wet silica manufactured by Nippon Silikani Gyo Co., Ltd.) was thoroughly kneaded with two rolls, and then mixed with 5 parts of organopolysiloxane and Antige RD (as an anti-aging agent)
0.5 part of quinoline anti-aging agent (manufactured by Kawaguchi Chemical Co., Ltd.), 1.0 part of stearic acid and 30 parts of dicumyl peroxide were added and uniformly mixed with two rolls at a temperature of 1.
Pressing (primary vulcanization) at 60"C for 20 minutes at a pressure of 200/9/crl to obtain a sheet with a thickness of 2 mm. This was then heat treated in a hot air circulation oven at 150 °C for 2 hours ( (secondary vulcanization).

The surface of this sheet was shiny.

Polyester tape 31B (
Acrylic adhesive tape manufactured by Nitto Electric Industry Co., Ltd., width 5crIL
) was applied evenly and then peeled off, and the tape was easily peeled off by just pulling it lightly. Also, hold the rubber sheet at 150°
Even after heating for 168 hours in a hot air circulation oven (C), the rubber surface did not lose its luster.

On the other hand, as a comparative example, a rubber sheet was prepared under the same conditions as above except that only organopolysiloxane (G) was not added, and the same test was conducted. showed that. still,
The rubber sheet was glossy before heating, but at 150°C it became 16
After heating for 8 hours, the gloss had been lost.

From this result, it is presumed that it is useful for wiper blade rubber for automobiles, weather strip rubber, Prada rubber for tire molding, rubber for rolls, etc.

Patent applicant: Toray Silicone Co., Ltd. 31- 631-

Claims (1)

[Claims] +R'-COO bonded to silicon atom in 11 molecules
H group, -R2-8R group, -R3-OY group, and. -R'-X group [where R'l R2, R3 and R
4 is a divalent organic group; Y is a hydrogen atom or a monovalent hydrocarbon group; It is. ] Among the four types of functional groups shown in
An organopolysiloxane lubricant whose main ingredient is an organopolysiloxane having at least one each of two types of arbitrarily selected functional groups. 2. The only other organic group bonded to the silicon atom of the organopolysiloxane is a methyl group. The lubricant according to claim 1. 3. Other organic groups bonded to the silicon atom of the organopolysiloxane are a methyl group and a phenyl group. The lubricant according to claim 1. 4 The number of siloxane units of the organopolysiloxane is 5
~1000 pieces. The lubricant according to claim 1, wherein the object to which lubricity is imparted is a synthetic resin covered with a synthetic resin. It is mu. The lubricant according to claim 1. 6. The lubricant according to claim 5, wherein the synthetic resin is a vinyl chloride resin, a vinyl acetate resin, a polyurethane resin, or an epoxy resin, and the synthetic rubber is an ethylene-propylene-diene rubber. 7.Synthetic resin is equivalent to 100 parts of synthetic rubber. The lubricant according to claim 5 or 6, wherein the organopolysiloxane is used in a range of 0.05 to 20 parts.