JPH09157405A - Sliding elastomer molding product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molding product, comprising a specific elastomer dispersed on the surface of a molding product in a specific resin and useful as an automotive glass run, etc., and excellent in sliding properties at a low cost. SOLUTION: This molding product comprises (A) an elastomer having 20-100 A hardness specified by JIS and (B) a resin having >=50 deg.C glass transition temperature. The component (B) has 0.5-500μm particle diameter and is dispersed in the component (A) and the surface of the molding product. The difference in solubility parameter between the components (A) and (B) is >=0.4 and the weight ratio of the components (A) and (B) is (99:1) to (60:40). The component (A) is at least one selected from the group consisting of an olefin/diene copolymer, a polyurethane resin and a polyurethane-urea resin. The component (B) is preferably at least one selected from the group consisting of a polystyrene, a styrene/(meth)acrylate copolymer and a polyamide.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an elastomer molded article having excellent slidability. More specifically, it relates to a low-hardness elastomer molded product suitable for automobile glass runs, copying machine cleaning blades, etc., at low cost and excellent in slidability.

[0002]

2. Description of the Related Art Conventionally, as a slidable elastomer,
A low-hardness elastomer chemically modified with a compound containing fluorine or polysiloxane (for example, Japanese Patent Application Laid-Open No. H06-242242).
No. 1917); a material having improved slidability by forming a coating film that imparts slidability on the surface of a low hardness elastomer (for example, JP-A-5-171109);
A low hardness elastomer to which fine powder of a fluorine-containing resin is added (for example, JP-A-7-287494);
Etc. are known.

[0003]

However, the above-mentioned materials have a problem that the cost is very high and the unreacted raw material used for the modification bleeds out over time on the surface of the molded product. In the case of the above, there is a problem that a step for forming a coating film is required, resulting in high cost, and the repeated use causes deterioration of the coating film and deterioration of slidability. In order to uniformly disperse the fluorine-containing resin in the molded product, a high shearing force disperser is required, resulting in high cost, and the problem that fine powder of the fluorine-containing resin falls off from the surface of the molded product when repeatedly used. was there.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the cost can be reduced without using a compound containing fluorine or polysiloxane for improving slidability. Further, they have found that a low-hardness elastomer molded body excellent in slidability can be obtained, and arrived at the present invention.

That is, the present invention is based on A specified by JIS.
A molded body comprising an elastomer (A) having a hardness of 20 to 100 and a resin (B) having a glass transition point of 50 ° C. or higher, wherein (B) has a particle size of 0.5 μm to 500 μm (A). It is a slidable elastomer molded body dispersed in the inside and on the surface of the molded body.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The elastomer (A) used in the present invention includes olefin / diene copolymers (EPDM, TPO, etc.), ethylene / vinyl acetate copolymers, ethylene / (meth) acrylic acid copolymers. Coalesce, ethylene / (meth) acrylic acid copolymer metal crosslinked product, ethylene / (meth) acrylic acid ester copolymer, polyurethane resin, polyurethane urea resin, styrene / diene copolymer (ABS, SBR, SBC, etc.), Examples thereof include soft vinyl chloride, polyester elastomer, polyamide elastomer, silicone rubber (silicon RTV, etc.).

Of these, preferred are olefins /
These are diene copolymers, polyurethane resins and polyurethane urea resins.

The number average molecular weight of (A) is not particularly limited, but is usually 10,000 to 3,000,000, preferably 10,000 to 1,000,000.

The A hardness defined by JIS (A) is usually 20 to 100, preferably 40 to 75. Hardness is 1
When it exceeds 00, the flexibility is reduced and it becomes unsuitable for use in glass run for automobiles and the like, and when it is less than 20, tackiness appears on the surface of the molded article and slidability deteriorates.

The resin (B) used in the present invention includes polystyrene, styrene / (meth) acrylic acid ester copolymer, polypropylene, polyamide, polyester, epoxy resin, furan resin, guanamine resin,
Examples thereof include phenol resin, vinyl ester, melamine resin, alkyd resin, urea resin, and hard vinyl chloride.

Of these, preferred are polystyrene, styrene / (meth) acrylic acid ester copolymers and polyamides.

The number average molecular weight of (B) is not particularly limited, but is usually 50,000 to 3,000,000, preferably 100,000 to 1,000,000. The glass transition point (Tg) of (B) is usually 50 ° C. or higher, preferably 100 ° C. or higher. (B)
When the Tg of the product was less than 50 ° C, it was dispersed on the surface of the molded product (B)
The particles are softened by frictional heat during use and the slidability of the molded product is deteriorated.

In the present invention, the particle size of (B) dispersed in (A) and on the surface of the molded product is usually 0.5 μm to 5 μm.
It is 00 μm, preferably 1.0 μm to 50 μm.
If the particle size of (B) is less than 0.5 μm, the number of particles of (B) dispersed and exposed on the surface of the molded product decreases, and the slidability becomes insufficient. It becomes difficult to disperse the particles uniformly.

The weight ratio of (A) and (B) in the slidable elastomer molding of the present invention is usually (50 to 99):
(1 to 50), preferably (60 to 95): (5 to 4)
0). When the ratio of (A) is less than 50, the flexibility of the molded product is reduced, and when it exceeds 99, the slidability is deteriorated.

In the present invention, the difference between the absolute values of the SP values of (A) and (B) is preferably 0.4 or more. SP
If the difference between the absolute values is less than 0.4, (B) in (A)
Is dissolved and the particles of (B) are not formed, so that the slidability of the molded article is reduced. The SP value is calculated by the Fedors method [Polym. Eng. Sci. 14 (2) 152,
(1974)].

The method for producing the slidable elastomer of the present invention is not particularly limited, but the following method may be mentioned, for example. A method of forming (B) in molten (A) and mixing and dispersing. A method in which (A) and (B) are melted and mixed and dispersed. A method in which the raw material of (A) and the raw material of (B) are mixed, and (A) and (B) are simultaneously formed and mixed and dispersed. The particles of (B) are dispersed in the raw material of (A),
A method of forming (A) and mixing and dispersing. Of these, the preferred method is industrially excellent in productivity,
And (B) can be uniformly dispersed in (A).

As a condition of the above method, the temperature for melting (A) and the temperature for forming (B) are usually 1
The temperature is from 00 to 350 ° C, preferably from 100 to 200 ° C.
The pressure is not particularly limited, but when industrial production is considered-
It is 0.99 to 20 atm, preferably -0.90 to 10 atm. The mixing and dispersing time is preferably as short as possible so that thermal deterioration of each component during mixing does not occur, and is usually 0.5 to 60 minutes, preferably 1 to 30 minutes. As a condition of the method (1), the temperature at which (B) is dispersed in the raw material (A) and the temperature at which (A) is formed are usually 100 to 3.
The temperature is 50 ° C, preferably 100 to 200 ° C. The pressure is not particularly limited, but when industrial production is considered, it is usually -0.99.
-20 atm, preferably -0.90-10 atm.
The mixing and dispersing time is preferably as short as possible so that thermal deterioration of each component during mixing does not occur, and usually 0.5 to
60 minutes, preferably 1 to 30 minutes.

Examples of the mixing / dispersing (reacting) apparatus include various known mixers such as an extruder, a kneader, a Banbury mixer, and a planetary mixer.

In the slidable elastomer molding of the present invention, if necessary, a dispersant, a release agent, a pigment, a dye, a weather resistance stabilizer, a lubricant, a plasticizer, a coupling agent, a heat resistance stabilizer, and a flame retardant. Known additives such as the above may be added.

As a molding apparatus for obtaining the slidable elastomer molding of the present invention, various known molding machines (for example,
Injection molding machine, press molding machine, extrusion molding machine, rotational molding machine and the like).

[0021]

EXAMPLES The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. In the following description, “part” indicates “part by weight” and “%” indicates “% by weight”.

Production Example 1 Polystyrene glycol containing polypropylene having a hydroxyl value of 56.1 [SANNIX SP-3000; Sanyo Chemical Industries, Ltd., polystyrene content 30 in a four-necked flask equipped with a stir bar and thermometer. %)] 80 parts, and heated to 110 ° C. under a reduced pressure of 3 mmHg for 1
Dehydration was performed for hours. Subsequently, 20 parts of isophorone diisocyanate [hereinafter abbreviated as IPDI] was additionally charged, and the temperature was 110 ° C.
Was reacted for 10 hours to obtain a polyurethane prepolymer (A1) having an isocyanate group at the terminal. The (A1)
Had a free isocyanate content of 4.2%.

Example 1 80 parts of EPDM rubber [E505; manufactured by Sumitomo Chemical Co., Ltd.],
15 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of azobisisobutyronitrile and 2 parts of a white pigment [Taipaque R-820; manufactured by Ishihara Sangyo Co., Ltd.] are twin-screw extruder [Toyo Seiki Seisakusho KK] Made 2D25-S type, 20mm
φ, L / D = 25], cylinder temperature 180 ° C
Melt kneading for 10 minutes, molding the kneaded material using an extrusion molding machine, and a thickness of 3 m in which resin particles are uniformly dispersed on the surface.
A plate-like slidable elastomer molded product (D1) of m was obtained.
The average particle size of the surface-dispersed particles measured with a video microscope (manufactured by Meishin Machinery Co., Ltd.) (the same applies hereinafter) is about 15
μm.

Example 2 78 parts of EPDM rubber [E505; manufactured by Sumitomo Chemical Co., Ltd.]
20 parts of a styrene / acrylic copolymer [Haimer RSE11; manufactured by Sanyo Kasei Co., Ltd.] and 2 parts of a white pigment [Tapeque R-820; manufactured by Ishihara Sangyo Co., Ltd.] are twin-screw extruder [Toyo Seiki Seisakusho KK] Made 2D25-S type, 20mm
φ, L / D = 25], cylinder temperature 180 ° C
Then, the mixture was melt-kneaded for 5 minutes to obtain a slidable elastomer molding (D2) in the same manner as in Example 1. The average particle size of the surface-dispersed particles was about 10 μm.

Example 3 10 parts of styrene, 3 parts of methyl methacrylate, 0.2 part of azobisisobutyronitrile, and a hydroxyl value of 56.1.
Polycaprolactone diol (59 parts), 1,4-butanediol (6 parts), and dicyclohexylmethane diisocyanate [hereinafter abbreviated as MDI-H] (22 parts) are twin-screw extruders (manufactured by Toyo Seiki Seisakusho Co., Ltd. 2D25-S type, 20 mm).
φ, L / D = 25], cylinder temperature 180 ° C
And melt-kneaded for 10 minutes to obtain a slidable elastomer molding (D3) in the same manner as in Example 1. The average particle size of the surface-dispersed particles was about 20 μm.

Example 4 Polyurethane prepolymer (A1) 85 obtained in Production Example 1
Part, 1,4-diaminocyclohexane 8 parts and a white pigment [Taipaque R-820; manufactured by Ishihara Sangyo Co., Ltd.] 2 parts by twin-screw extruder [manufactured by Toyo Seiki Seisakusho 2D25-S type,
20 mmφ, L / D = 25] and melt-kneaded for 5 minutes at a cylinder temperature of 180 ° C., and then, in the same manner as in Example 1 to obtain a slidable elastomer molded body (D4). The average particle size of the surface-dispersed particles was about 5 μm.

Comparative Example 1 68 parts of polycaprolactone diol having a hydroxyl value of 56.1, 7 parts of 1,4-butanediol and MDI-H2
5 parts and a white pigment [Taipaque R-820; manufactured by Ishihara Sangyo Co., Ltd.] 3 parts using a twin-screw extruder [manufactured by Toyo Seiki Seisakusho Co., Ltd. 2D25-S type, 20 mmφ, L / D = 25] Melt-kneading at a cylinder temperature of 180 ° C. for 5 minutes, and then in the same manner as in Example 1 below, a comparative elastomer molding (D
5) was obtained.

Comparative Example 2 98 parts of EPDM rubber [E505; manufactured by Sumitomo Chemical Co., Ltd.] and white pigment [Taipek R-820; Ishihara Sangyo Co., Ltd.]
2 parts of a twin-screw extruder [manufactured by Toyo Seiki Seisakusho Co., Ltd. 2D2]
5-S type, 20 mmφ, L / D = 25], and melt-kneaded at a cylinder temperature of 180 ° C. for 5 minutes.
A comparative elastomer molded product (D6) was obtained in the same manner as in.

Physical Property Measurement Example 1 Hardness (JIS A) of the elastomer moldings (D1) to (D6) obtained in Examples 1 to 4 and Comparative Examples 1 and 2.
Was measured. Table 1 shows the results.

[0030]

[Table 1]

Physical Property Measurement Example 2 The surface friction resistance of the elastomer molded bodies (D1) to (D6) obtained in Examples 1 to 4 and Comparative Examples 1 and 2 to glass was measured. The results are shown in Table 2. Incidentally, the surface friction measuring device "Tribogear TYPE = 14DR" manufactured by Shinto Chemical Co., Inc. was used for measuring the surface friction resistance.

[0032]

[Table 2]

[0033]

The slidable elastomer molding of the present invention is
Excellent slidability is obtained without using a compound containing fluorine or polysiloxane for improving slidability.
Further, the elastomer mixture can be produced in one shot by using a general-purpose kneader such as a twin-screw extruder, and can be obtained at low cost. Since the above-mentioned effects are exhibited, the slidable elastomer molded article of the present invention can be suitably used for a wide range of applications such as elastomer for automobile Gran Run and cleaning blade for copying machines.

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Claims (5)

[Claims] 1. A hardness specified by JIS is 20 to 10
A molded product comprising an elastomer (A) of 0 and a resin (B) having a glass transition point of 50 ° C. or higher, wherein (B)
Is dispersed in (A) and on the surface of the molded product in a particle size of 0.5 μm to 500 μm. 2. The molded article according to claim 1, wherein the difference in absolute value of the solubility parameter (SP value) between (A) and (B) is 0.4 or more. 3. A weight ratio of (A) to (B) is 99: 1 to 6
The molded product according to claim 1 or 2, which has a ratio of 0:40. 4. The molded product according to claim 1, wherein (A) is at least one elastomer selected from the group consisting of an olefin / diene copolymer, a polyurethane resin, and a polyurethane urea resin. 5. (B) is polystyrene, styrene /
The molded product according to claim 1, which is at least one resin selected from the group consisting of (meth) acrylic acid ester copolymers and polyamides.