JP3328152B2 - Release agent containing silicone oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold release agent suitable for heat and pressure molding of rubber and resin products.
The present invention relates to a silicone oil-containing release agent which is suitable for heat and pressure molding of a resin product, has excellent releasability, does not impair the aesthetic appearance of a final product, and does not cause product defects.

[0002]

2. Description of the Related Art Conventionally, when molding a rubber product, a thermoplastic resin product, or a composite product of rubber and a thermoplastic resin by heating and pressing (vulcanizing) molding, it is necessary to improve the releasability from a mold. ,
Various release agents are applied in advance. For example, as an inner mold release agent for a tire, an oil-in-water emulsion (silicone emulsion) of dimethyl shikirsan is mixed with a fine powder of an inorganic compound having high lubricity such as mica, talc and a surfactant. Used. When the release agent needs to be blackened for the purpose of improving the appearance of a black product, a black dye such as carbon black is added to the composition.

[0003]

However, in the process of producing rubber or resin products having a vivid color or pattern, if the above-mentioned release agent is used, heating and pressing (vulcanization) molding is completed. There is a problem that the surface of the product is dyed white or black due to the release agent, and the value of the product is reduced.

Further, in order to make the release agent transparent, only a silicone emulsion is used and at least a part thereof is crosslinked in a laminate of a thin film of rubber and a thermoplastic resin or in a rubber and a thermoplastic resin. When a laminate of a thin film of a thermoplastic elastomer composition in which an elastomer component is dispersed is heated and pressed (vulcanized) and molded, a silicone emulsion and a thermoplastic resin, and a silicone emulsion and a thermoplastic elastomer composition are incompatible. For this reason, when the temperature of the film rises during heating and pressurizing, for example, when a film of nylon 11 or the like is melted, the silicone oil flows and is unevenly distributed, and the nylon 11 and the silicone oil are incompatible components. Therefore, a phase separation phenomenon occurs between the two, a hole may be opened in the layer of the thermoplastic resin or the thermoplastic elastomer composition, There was to be a goods defective.

As an emulsion containing a silicone oil, JP-A-60-36563 discloses an aqueous emulsion of a hydroxyl-terminated polydiorganosiloxane having a molecular weight of 50.000 or more, a silicone resin, a catalyst compound, a thixotropic filler, and a non-thixotropic. A stable silicone emulsion containing a filler is disclosed. However, this publication aims to obtain a coating composition for paints and sealants, and there is no description that this silicone emulsion is used as a release agent, which is completely different from the present invention.

Accordingly, the present invention relates to a thermoplastic elastomer composition comprising a rubber, a thermoplastic resin, or an elastomer component at least partially cross-linked in a thermoplastic resin, or a laminate of the thermoplastic elastomer composition and the like. An object of the present invention is to provide a release agent which has good releasability from a mold during heat and pressure molding, does not impair the original color of the product, and prevents the occurrence of product defects.

[0007]

According to the present invention, formula (I):

Embedded image (In the formula, n is an arbitrary integer.) In an oil-in-water emulsion obtained by emulsifying a silicone oil having a dimethylsiloxane structure with an emulsifier, 100 parts by weight of the silicone oil in the emulsion has silanol ( S
There is provided a release agent suitable for heat and pressure molding of rubber and resin products, which is obtained by blending silica particles having an iOH) group in an amount of 4 parts by weight or more and imparting viscosity.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the release agent according to the present invention is an oil-in-water emulsion obtained by emulsifying a silicone oil having a viscosity of preferably 1 to 1,000,000 cst (25 ° C.) with an emulsifier, and the silicone emulsion. 4 parts by weight or more of silica particles having a silanol group (SiOH) on the surface to impart thixotropic property to 100 parts by weight of the silicone oil therein, preferably when the release agent needs to have transparency. May be blended in an amount of 4 to 40 parts by weight, and if necessary, water, a dispersant, and a preservative may be blended.

The silicone oil having the structure of the above formula (I), which is a main component of the release agent of the present invention, is an oil-in-water emulsion with an emulsifier.

The viscosity of the base silicone oil of the release agent of the present invention is preferably 100 to 1,000,000 cSt (25 ° C.), more preferably 100,000 to 1,000,000 cSt (25 ° C.). Examples of such a silicone emulsion include TSF451 manufactured by Toshiba Silicone Co., Ltd., and SH490, SM8701, S870 manufactured by Dow Corning Toray Silicone Co., Ltd.
Commercial products such as H203 can be used. Further, n in the above formula (1) may be set so as to have the above-mentioned viscosity, and is, for example, n = 2.1 × 10 ^{3 to} 1.3 × 10 ³ .

The silica particles having a silanol group on the surface to be incorporated in the release agent of the present invention have a primary particle diameter of 5 to 50 n.
m, preferably 7 to 30 nm, and a specific surface area measured by a BET (nitrogen) method of 50 to 380 m ² / g, preferably 20
It is preferably from 0 to 380 m ² / g. If the primary particle size is too large, the dispersibility in water deteriorates, which is not preferable. On the other hand, if the specific surface area of the silica particles is too low, the thickening effect is undesirably reduced.

If the content of the silica particles in the release agent of the present invention is small, the effect of thickening is insufficient, so that a hole is formed in the thermoplastic resin or the thermoplastic elastomer composition, and as described below. When the product is finished, stickiness may occur. On the other hand, if the amount is too large, the product becomes white (the transparency is lost) at the time of finishing the product, which may not be preferable in terms of the aesthetic appearance of the product. If no silanol groups are present on the surface, no interaction due to hydrogen cross-linking occurs, and a three-dimensional network structure cannot be obtained, and thus a thickening effect cannot be obtained.

Typical materials used for molding under heat and pressure using the release agent according to the present invention include elastomer components (including rubbers) (for example, although not particularly limited, diene rubbers and their diene rubbers). Hydrogenated products (for example, natural rubber, polyisoprene rubber, epoxidized natural rubber, styrene-butadiene copolymer rubber, polybutadiene rubber (high cis BR,
Low cis BR), NBR, hydrogenated NBR, hydrogenated SB
R), various elastomers, for example, olefin rubber (for example, ethylene propylene copolymer rubber (EPDM, EP
M), maleic acid-modified ethylene propylene copolymer rubber (M-EPM), IIR, isobutylene and aromatic vinyl or diene monomer copolymer), halogen-containing rubber (for example, brominated butyl rubber, chlorinated butyl rubber, isobutylene-p) -Brominated methylstyrene copolymer (Br)
-IPMS), chlorosulfonated polyethylene (CS
M), chlorinated polyethylene (CM), maleic acid-modified chlorinated polyethylene (M-CM), thermoplastic elastomers (eg, styrene-based elastomers, olefin-based elastomers, ester-based elastomers), and the like. It may be a composition to which a compounding agent such as a vulcanizing agent is added), a thermoplastic resin (for example, although not particularly limited, a polyamide resin (nylon), a polyolefin resin (polyethylene, polypropylene, etc.), a polyester resin ( Polybutylene terephthalate, polyethylene terephthalate, etc.), vinyl-based resins (vinyl chloride, vinylidene chloride, etc.), and thermoplastic elastomer compositions (the above-mentioned elastomer components at least partially cross-linked in thermoplastic resin are dispersed) Things) It is possible.

The release agent according to the present invention includes, in addition to the silicone oil emulsion and silica particles described above,
Water, a dispersant (for example, various surfactants), and a preservative (for example, sodium nitrite) can be added as necessary.

[0015]

EXAMPLES The present invention will be further described with reference to the following examples, but it goes without saying that the scope of the present invention is not limited to these examples. Conventional Examples 1, Examples 1-4 and Comparative Examples 1-2 As an example where the transparency of the release agent is not required, a laminate of a non-colored nylon 11 film and a textile reinforcing rubber is heated and pressed. The following examples are shown as examples used in molding (Examples showing that they are effective as release agents for thermoplastic resins and rubbers). The composition (parts by weight) of the release agent is as shown in Table I, and the details of the components are as follows. Silicone emulsion: Toray Dow Corning Silicone SH490 silica powder: Nippon Aerosil A
EROSIL200 (primary particle diameter about 12 nm, specific surface area 2
(00 ± 25 m ² / g) The evaluation results are shown in Table I.

[0016]

[Table 1]

Preparation of Release Agent The release agent of Conventional Example 1 A silicone emulsion, water and a nonionic surfactant were added with stirring according to the formulation shown in Table I above to form a dispersion.
To this, mica fine powder and talc fine powder were gradually added to obtain a release agent. Release Agents of Comparative Examples 1 and 2 and Examples 1 to 4 Silicone emulsion, water and silica powder were added under stirring according to the formulations in Table I above to obtain release agents.

Preparation of Test Laminate A 100 μm thick nylon 11 film (manufactured by Atochem Co., Ltd., Rilsan BESN O TL) was used.
A laminated film was prepared by laminating a μm adhesive film. On the other hand, the rubber composition having the composition shown in Table II was
A fiber reinforced rubber was produced by coating both sides of the aligned polyester cord. Next, prepare a laminated film that is bonded so that the adhesive side of the laminated film is in contact with the fiber-reinforced rubber, further apply a release agent to the nylon film surface and the fiber-reinforced rubber surface using a brush, and after drying at room temperature, The test laminate was obtained by placing it in a mold and pressing at 190 ° C. for 10 minutes.

Preparation of Rubber Composition Preparation Method A masterbatch was prepared by mixing a vulcanization accelerator and raw materials other than sulfur in a closed mixer. The standard mixing time is 3.
The release temperature was 150 ° C. in 5 minutes. The remaining compounding agent was added to the master batch using an open roll to prepare an unvulcanized rubber.

[0020] Table II ────────────────── Component Parts by weight Natural rubber 80 SBR1502 20 FEF carbon black 50 Stearic acid 2 Zinc oxide 3 Sulfur 3 Vulcanization accelerator (NS ) 1 aroma oil 2 ──────────────────

Natural rubber: RSS # 1 SBR1502: Nipol 1502 Nippon Zeon Co., Ltd. FEF Carbon black: HTC100 Chubu Carbon Co., Ltd. Stearic acid: Lunac YA Kao Co., Ltd. Zinc oxide: Ginrei Zinc Flower Toho Zinc Co., Ltd. ) Sulfur: Powdered sulfur Karuizawa Smelting Co., Ltd.
Vulcanization accelerator (NS): Noxeller NS-P Ouchi Shinko Chemical Co., Ltd. Aroma oil: Komorix 300 Nippon Oil Co., Ltd.

[0022] After kneading the blended ingredients in a twin-screw kneader at 120 ° C. illustrated in preparing preparation Table III of the adhesive, to prepare a film of 30μm in T-die extruder.

Table III {Component parts by weight Epoxy-modified SBS 80 Rosin ester 20 Peroxide 50} ──────── Epoxy-modified SBS: ESBS AT015 Daicel Chemical Co., Ltd. Rosin ester: Pencel AD Arakawa Chemical Co., Ltd. Peroxide: Parkadox 14-40 Kayaku Akzo Co., Ltd.

As is clear from the results in Table I, Conventional Example 1
However, when the nylon film and the rubber side of the finished product are touched, there is a problem that the powder of the release agent on the surface is remarkably dropped, and the hands of the operator are stained white. In contrast, in Examples 1 to 4 using the release agent according to the present invention, holes were formed in the nylon film,
There was no stickiness on the finished product surface, and good results were obtained. On the other hand, Comparative Example 1 contained no silica powder,
The silicone emulsion is not thickened, which causes perforations in the nylon film, and the finished product surface becomes sticky with silicone oil. In Comparative Example 2, since the amount of silica powder was small, the thickening effect of the silicone emulsion was insufficient, so that a hole was formed in the nylon film, and the nylon film side and the rubber side surface of the finished product had silicone. The oil is sticky.

Conventional Example 2, Examples 5 to 8 and Comparative Examples 3 to 4 When the tire is vulcanized using the uncolored thermoplastic elastomer film as an inner liner in the composition (parts by weight) shown in Table IV, the inner surface of the tire is separated. Examples of use as mold agents (examples where the release agent does not require transparency) are shown below.

[0026]

[Table 2]

Production of Evaluation Tire and Evaluation A thermoplastic polyester elastomer was extruded by T-die to form a belt-like film having a width of 360 mm and a thickness of 100 μm. The thermoplastic polyester elastomer used was Hytrel 5577 manufactured by Du Pont-Toray Co., Ltd. The thermoplastic elastomer film and the adhesive film were laminated to form an integrated film, which was then placed on the drum side by the thermoplastic elastomer film. After winding the tire member around the tire forming drum so that the adhesive is on the tire member side, laminating the tire member thereon, inflating the green tire, and applying a release agent to the inner liner on the inner surface of the tire. After drying, it was vulcanized (condition: 180 ° C. × 10 minutes) to produce a tire having a tire size of 165SR13. The evaluation results are shown in Table IV.

As shown in Table IV, in Conventional Example 2, the inner liner did not have a hole, but when the tire touched the inside of the tire after vulcanization, the release agent powder on the surface adhered to the hands of the handler and turned black. Get dirty. On the other hand, Examples 5 to 8 have no perforation of the inner liner because the viscosity increase by the silica powder is sufficiently performed, and there is no stickiness of the tire inner surface after vulcanization,
Good product tires were obtained. On the other hand, in Comparative Example 3, since no silica powder was contained, the viscosity of the silicone emulsion was not increased, so that a hole was formed in the inner liner, and the surface of the finished product was sticky with silicone oil. In Comparative Example 4, the effect of thickening the silicone emulsion was insufficient due to the small amount of the silica powder, so that a hole was formed in the inner liner, and the tire inner surface became sticky with the silicone oil after vulcanization.

Conventional Example 3, Examples 9-12 and Comparative Examples 5
6 This example shows an example in which ordinary butyl rubber is used as an inner liner and vulcanization of the tire is used as a release agent on the inner surface of the tire (an example where transparency of the release agent is not required).

Preparation of Release Agent According to the formulation (parts by weight) in Table V of the release agent of the conventional example, a silicone emulsion,
Water and a surfactant were added with stirring to form a dispersion, and mica fine powder, talc fine powder, and carbon black were gradually added thereto to obtain a release agent. A silicone emulsion according to the formulation (parts by weight) of the release agent in Table V of Comparative Examples and Examples ,
Water and silica powder were added with stirring to obtain a release agent.

Preparation of Adhesive The same as in Examples 1 to 4.

[0032]

[Table 3]

Production of Evaluation Tire and Evaluation An inner liner layer (thickness: 500 μm) made of unvulcanized butyl rubber having the composition shown in Table VI was provided on the inner surface of the evaluation green tire via a tie rubber of about 700 μm. A release agent is applied to the inner liner on the inner surface of the tire, dried and then vulcanized (condition: 180 ° C. × 10 minutes), and the tire size is 165S.
An R13 tire was produced.

Preparation Method A masterbatch was prepared by mixing zinc oxide, a vulcanization accelerator and raw materials other than sulfur in the composition shown in Table VI using a closed mixer. The standard mixing time is 3.5 minutes and the release temperature is 15
It was 0 ° C. The remaining compounding agent was added to the master batch using an open roll to prepare an unvulcanized rubber.

[0035] Table VI ─────────────────── Component Parts by weight of the brominated butyl rubber 100 FEF carbon black 50 Stearic acid 1 Zinc oxide 3 Sulfur 1 Vulcanization accelerator (DM ) 1 aroma oil 10kg

[0036] Brominated butyl rubber: Exxon bromobutyl 2244, manufactured by Exxon Chemical Co., Ltd. FEF Carbon black: HTC100, manufactured by Chubu Carbon Co., Ltd. Stearic acid: Lunac YA, manufactured by Kao Corporation Zinc oxide: manufactured by Toho Zinc Co., Ltd. Sulfur: Powdered sulfur Karuizawa Refinery Co., Ltd.
Vulcanization accelerator (NS): Noxeller NS-P Ouchi Shinko Chemical Co., Ltd. Aroma oil: Komorix 300 Nippon Oil Co., Ltd.

From the results shown in Table V, in Conventional Example 2, when the inner surface of the tire is touched after vulcanization, the powder of the release agent on the surface adheres to the hands of the handler and is stained black. On the other hand, in Examples 9 to 12, since the silica powder was sufficiently mixed, the tire inner surface was not sticky after vulcanization, and a clean inner product tire was obtained. On the other hand, in Comparative Example 5, when the tire inner surface was touched after vulcanization, the tire was sticky by the silicone oil. In Comparative Example 6, since the silica powder was small, the tire inner surface was sticky by the silicone oil after the vulcanization.

Preparation of Release Agent Same as in Conventional Example 2, Examples 9 to 12, and Comparative Examples 5 to 6.

Preparation of Adhesives Same as Conventional Example 2, Examples 9 to 12, and Comparative Examples 5 to 6.

Conventional Example 4, Examples 13 to 15 and Comparative Example 7
Examples 9 to 9 are examples in which a release agent shown in Table VII was used as a release agent for the inner surface of a tire when a tire was vulcanized using a blue colored thermoplastic elastomer film as an inner liner (transparent release agent). An example in which the property is required is shown.

[0041]

[Table 4]

Preparation and Evaluation of Evaluation Tire 100 parts by weight of Br-IPMS (Exxpro 90-10 manufactured by Exxon Chemical), paraffin-based process oil 20
The parts by weight were mixed in a closed mixer to prepare a rubber master batch, and pelletized with a rubber pelletizer. Thereafter, the components shown in Table VIII were kneaded with a twin-screw mixer, pelletized with a resin pelletizer, and formed into a belt-shaped thermoplastic elastomer film (colored blue) with a width of 360 mm and a thickness of 100 μm by T-die extrusion. did.

[0043] Table VIII ─────────────────── Component Parts by weight of nylon 11 30 Color masterbatch 10 rubber master batch 60 Zinc oxide 0.3 Stearic acid 1.2 stearic Zinc acid 0.6 ───────────────────

Nylon 11: Rilsan BESN OTL Atochem Co., Ltd.
Color Masterbatch: PAM (F) 10989 BLUE (Nylon 12 base)
Manufactured by Dainichi Seika Co., Ltd. Zinc oxide: Ginrei zinc flower Toho Zinc Co., Ltd. Stearic acid: Lunac YA Kao Co., Ltd. Zinc stearate: Zinc stearate Seido Chemical Co., Ltd.

After laminating the thermoplastic elastomer film and the adhesive film to form an integrated film, this is molded into a tire such that the thermoplastic elastomer film is on the drum side and the adhesive is on the tire member side. After winding around a drum, a tire member is laminated thereon, the tire is inflated to form a green tire, a release agent is applied to an inner liner on the inner surface of the tire, dried, and then vulcanized (condition: 18).
(0 ° C. × 10 minutes), and a tire having a tire size of 165SR13 was produced.

As shown in Table VII, in the conventional example 3, the perforation of the inner liner did not occur, but the color of the inner liner was completely invisible due to the mold release agent. The release agent powder on the surface adheres to the hands of the handler and stains black. In contrast, in Examples 13 to 15,
Since the release agent was transparent, the color of the inner liner was visible, and there was no perforation in the inner liner and no stickiness on the inner surface of the tire after vulcanization, and a good product tire was obtained. on the other hand,
In Comparative Example 7, since no silica powder was contained, the silicone emulsion was not thickened, which caused perforations in the inner liner, and the finished product surface was sticky with silicone oil. Insufficient thickening effect of the silicone emulsion caused by perforation of the inner liner occurs, and the surface of the finished product becomes sticky with silicone oil. Further, in Comparative Example 9, no perforation occurs in the inner liner, but since the amount of the silica powder exceeds 40 parts by weight, the color (white) of the silica powder is conspicuous, and the color of the inner liner is not visible. In addition, the release agent and the adhesive agent are the same as those of the conventional example 2 and the examples 9 to
12 and Comparative Examples 5 to 6 were used.

Conventional Example 5, Examples 16 to 18, and Comparative Example 1
Examples of using a release agent shown in Table IX as a release agent for the outer surface side of the tire when vulcanizing a tire having a thermoplastic elastomer film colored 0 to 12 blue adhered to the outer surface side of the tire (release) An example in which transparency of a mold agent is required is shown.

[0048]

[Table 5]

Preparation and Evaluation of Evaluation Tire 100 parts by weight of Br-IPMS (Exxpro 90-10 manufactured by Exxon Chemical) and paraffin-based process oil 2
0 parts by weight were mixed in a closed mixer to prepare a rubber master batch, and pelletized with a rubber pelletizer.
Thereafter, each component of the composition (parts by weight) shown in Table X was kneaded with a twin-screw mixer and pelletized with a resin pelletizer.
T-die extrusion molding, 360mm width and 100μm thickness
A belt-shaped thermoplastic elastomer film (colored blue) was prepared.

[0050] Table X ─────────────────── Component Parts by weight of nylon 11 30 Color masterbatch 10 rubber master batch 60 Zinc oxide 0.3 Stearic acid 1.2 stearic Zinc acid 0.6 ───────────────────

Nylon 11: Rilsan BESN OTL Atchem Co., Ltd.
Color Masterbatch: PAM (F) 10989 BLUE (Nylon 12 base)
Manufactured by Dainichi Seika Co., Ltd. Zinc oxide: Ginrei zinc flower Toho Zinc Co., Ltd. Stearic acid: Lunac YA Kao Co., Ltd. Zinc stearate: Zinc stearate Seido Chemical Co., Ltd.

The thermoplastic elastomer film and the adhesive film were laminated to form an integrated film. Each unvulcanized tire rubber was molded on a molding drum according to a conventional method, and the adhesive of the above-mentioned integrated film was attached onto the tire side rubber so as to be on the side rubber side.
After molding the green tire by inflation, a release agent is applied to the side portion of the outer surface of the tire, dried, and then vulcanized (condition: 180 ° C. × 10 minutes) to obtain a tire size of 165SR1.
No. 3 tires were produced. The release agent and the adhesive used were the same as those of the conventional example 3, the examples 9 to 12, and the comparative examples 5 to 6.
The same one was used.

As shown in Table IX, in Conventional Example 4, when the side surface of the tire was touched after vulcanization, the powder of the release agent adhered to the hands of the handler and was stained black. In contrast, Examples 16 to
In No. 18, since the release agent was transparent, the color of the film adhered to the tire side was visible, and there was no stickiness on the tire side after vulcanization, and a good product tire was obtained. On the other hand, Comparative Examples 10 and 11 do not contain silica powder, or even if they contain silica powder, they are small, so they are transparent, so that the color of the thermoplastic film can be seen. However, the surface of the side portion of the tire is made of silicone oil. It was sticky. In Comparative Example 12, since the compounding amount of the silica powder exceeded 40 parts by weight, the color (white) of the silica powder was conspicuous, and the color of the inner liner was not visible.

[0054]

As described above, according to the present invention, according to the present invention, there is provided a thermoplastic elastomer composition comprising a rubber, a thermoplastic resin, or an elastomer component at least partially cross-linked in a thermoplastic resin, Alternatively, a silicone oil-containing release agent that has good release properties from the mold during heating and pressure molding of such laminates, does not impair the original color of the product, and prevents the occurrence of product defects is obtained. Can be

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-279571 (JP, A) JP-A-4-216864 (JP, A) JP-A 8-269338 (JP, A) JP-A 8- 151521 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 83/04 C08K 3/36 B29C 33/64

Claims (3)

(57) [Claims] 1. A formula (I): 1] (In the formula, n is an arbitrary integer.) In an oil-in-water emulsion obtained by emulsifying a silicone oil having a dimethylsiloxane structure with an emulsifier, 100 parts by weight of the silicone oil in the emulsion has silanol ( S
A release agent suitable for heat and pressure molding of rubber and resin products, which is obtained by compounding 4 parts by weight or more of silica particles having an iOH) group and imparting viscosity. 2. The transparent release agent according to claim 1, wherein the compounding amount of the silica particles is 4 to 40 parts by weight based on 100 parts by weight of the silicone oil in the emulsion. 3. The silica particles having a silanol group on the surface have a specific surface area of 50 to 380 m ² / g by a BET nitrogen method.
The release agent according to claim 1, wherein the primary particles have an average particle diameter of 5 to 50 nm.