JPH05140360A - Heat-resistant sponge rubber composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in oil resistance and solvent resistance, improved in low-temperature characteristics by incorporating a filler, crosslinking agent and foaming agent in a polymer produced by dissolving or swelling a noncrystalline fluorine-contg. polymer in an acrylic monomer followed by polymerizing the monomer. CONSTITUTION:The objective composition is obtained by incorporating (A) 100 pts.wt. of a polymer produced by dissolving or swelling a noncrystalline fluorine-contg. polymer in an acrylic monomer followed by polymerizing the monomer with (B) 0.1-100 pts.wt. of a filler, (C) 0.1-10 pts.wt. of a crosslinking agent and (D) 1-50 pts.wt. of a foaming agent. The noncrystalline fluorine-contg. polymer is e.g. a copolymer such as of vinylidene-fluoride/hexafluoropropylene base or vinylidene--fluoride/tetrafluoroethylene/hexafluoropropylene base.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat resistant sponge rubber composition.

[0002]

2. Description of the Related Art Fluorine-containing polymers such as amorphous vinylidene fluoride copolymers have recently been excellent in heat resistance, chemical resistance, oil resistance, solvent resistance, etc. Demand is increasing for materials such as sealing materials, diaphragms, and hoses. However, fluorine-containing polymers have problems in low temperature characteristics, for example, -20 ° C in most cases.
Since the rubber elasticity is lost when the temperature is below the limit of use and the temperature is lower than the limit of use, there are drawbacks that the use is limited and the cost is high. In addition, its specific gravity is higher than that of other rubbers, which is disadvantageous for some applications.

On the other hand, acrylic elastomers are excellent in oil resistance, but have a drawback that they are inferior in heat resistance at high temperatures of 150 ° C. or higher.

[0004] It has been proposed to mix a fluorine-containing polymer and an acrylic elastomer for the purpose of covering each other's drawbacks. In these compositions, these are mechanically kneaded and blended by using a roll or the like. Method is used, in this method it is difficult to finely and uniformly disperse both components, and when heat treatment for vulcanization,
Phase separation occurs and the degree of dispersion is further reduced. Therefore, there is a problem that satisfactory performance cannot be exhibited.

[0005]

The object of the present invention is to uniformly disperse a fluorine-containing polymer and an acrylic elastomer to obtain a vulcanized rubber that does not phase-separate, and take advantage of the respective characteristics to improve oil resistance and solvent resistance. An object of the present invention is to provide a heat-resistant sponge rubber composition having excellent heat resistance and improved heat resistance, and a heat-resistant sponge rubber composition having improved low-temperature characteristics.

[0006]

The present invention provides a polymer obtained by dissolving or swelling an amorphous fluorine-containing polymer in an acrylic monomer, and then subjecting this monomer to polymerization to polymerize it. Filler 0.1 to 10 parts by weight
The present invention relates to a heat-resistant sponge rubber composition containing 0 part by weight, a crosslinking agent 0.1 to 10 parts by weight, and a foaming agent 1 to 50 parts by weight.

The inventors of the present invention have conducted extensive studies to uniformly disperse the fluorine-containing polymer and the acrylic elastomer and to maintain the compatibility after the heat treatment for vulcanization. It has been found that the object can be achieved by adding a filler, a crosslinking agent and a foaming agent to a polymer obtained by polymerizing the acrylic monomer after dissolving or swelling the polymer in the acrylic monomer.

As the amorphous fluorine-containing polymer which can be dissolved or swelled in the acrylic monomer used in the present invention, for example, vinylidene fluoride / hexafluoropropylene type, vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene type, Vinylidene fluoride / chlorotrifluoroethylene-based vinylidene fluoride-based copolymers, tetrafluoroethylene / propylene-based, hexafluoropropylene / ethylene-based, fluoro (alkyl vinyl ether) (including those containing multiple ether bonds ) / Olefin copolymers, fluorosilicone rubber, fluorophosphazene rubber, and the like. Among these, vinylidene fluoride / hexafluoropropene-based, vinylidene fluoride / tetra Fluoroethylene / hexafluoropropylene-based and vinylidene fluoride / chlorotrifluoroethylene-based polymers are preferred.

In the present invention, amorphous means DSC (Differ
A melting point at which a melting point is not substantially observed in a peak of the ential scanning colorimeter).

In the present invention, the type of the acrylic monomer is not limited, but mono- or polyfunctional ones are included, and one or more types are used. The polyfunctional monomer is used in combination with the monofunctional monomer in a small amount. Is preferred. Preferred examples of these are, for example, methyl methacrylate (MMA), ethyl methacrylate (EMA), butyl methacrylate (BMA), 2-hydroxyethyl methacrylate (HEMA), glycidyl methacrylate (GM).
A), 2-methoxyethyl methacrylate (MEMA),
3- (trimethoxysilyl) propyl methacrylate (M
SPM), 2- (phenylphosphoryl) ethyl methacrylate (phenyl-P), 2-hydroxy-3- (β-naphthoxy) propyl methacrylate (HNPM), N-phenyl-N- (2-hydroxy-3-methacryloxy) Propylglycine (NPG-GMA), ethylene glycol dimethacrylate (EDMA or 1G), diethylene glycol dimethacrylate (DiEDMA or 2G), triethylene glycol dimethacrylate (TriEDMA or 3)
G), tetraethylene glycol dimethacrylate (TE
DMA or 4G), 1,4-butanediol dimethacrylate (1,4-BuDMA), 1,3-butanediol dimethacrylate (1,3-BuDMA), 2,2-bis [4- (2-hydroxy- 3-methacryloxypropoxy) phenyl] propane (Bis-GMA), 2,2-bis (4-methacryloxyphenyl) propane (BPDMA), 2,2-bis (4-methacryloxyethoxyphenyl) propane (Bis -MEP
P), 2,2-bis (4-methacryloxypolyethoxyphenyl) propane (Bis-MPEPP), di (methacryloxyethyl) trimethylhexamethylenediurethane (UDM
A), trimethylolpropane trimethacrylate (TM)
PT), CH ₂ = C (CH ₃ ) COOCH ₂ CF ₃ (3FM
_{A), CH 2 = C (} CH 3) COOCH 2 CF 2 CF 2 H (4
_{FMA), CH 2 = C (} CH 3) COOCH 2 CF 2 CF 3
(5FMA), CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₂ ) ₂ C
F ₃ (7FMA), CH ₂ = C (CH ₃ ) COOCH ₂ (C
_{F 2) 3 CF 2 H (} 8FMA), their corresponding respective acrylate can be exemplified each α- fluoroacrylate.

Examples of the α-fluoroacrylate include CH ₂ ═CFCOOCH ₂ CF ₂ CF ₂ H (4FF
A), CH ₂ = CFCOOCH ₂ CF ₂ CF ₃ (5FFA),
CH ₂ = CFCOOCH ₂ (CF ₂ ) ₃ CF ₂ H (8FF
A), CH ₂ = CFCOOCH ₂ (CF ₂ ) ₅ CF ₂ H (12F
FA) etc. can be illustrated.

A small amount of acrylonitrile, 2-chloroethyl vinyl ether, vinyl monochloroacetate, methyl vinyl dichlorosilane, etc. may be used in the monomer for the purpose of modification. When a polyfunctional monomer is used, the amount of the polyfunctional monomer used is preferably 1 to 20 parts per 100 parts (parts by weight, the same applies hereinafter) of the monofunctional monomer.

In the present invention, the ratio of the amorphous fluorine-containing polymer and the acrylic monomer can be appropriately determined, but it is usually preferable to use the latter in the range of 5 to 1000 parts relative to the former 100 parts.

In the present invention, the above fluorine-containing polymer is dissolved or swollen in an acrylic monomer, and then this is polymerized to be polymerized. At that time, it is carried out in the presence of a polymerization initiation source, and further polymerization is carried out. Inhibitors, reducing agents, transfer agents, etc. can also be added. As a polymerization initiation source, in addition to light and heat, benzoyl peroxide, azoisobutyronitrile (AIBN), camphorquinone (CQ), 9-fluorenone, tributylborane (TBB), benzophenone, and other polymerization initiators are reduced. As the agent, dimethylaminoethyl methacrylate (DMAEMA), dimethyl-p-toluidine (DMPT), etc., as the polymerization inhibitor, hydroquinone,
Examples of the transfer agent include hydroquinone methyl ester, and examples of the transfer agent include lauryl mercaptan. Then, by crosslinking the composition of the present invention and by using a polyfunctional acrylic monomer, IPN (Interter
-Penetrating Polymer Network) is formed, but here IPN is originally two kinds of chain polymers mixed in a liquid state (a solution is also possible), and both or one of them is crosslinked to entangle the molecular chains with each other. It is a polymer formed in a combined form. When applying the IPN method to the present invention,
The following method is usually used. That is, a polymer substance is polymerized in advance, and a monomer that forms a guest polymer is injected into the polymer substance, or the polymer is dipped and injected into a solution containing the monomer, and then heated or irradiated with light. A method of polymerizing by the above operation, mixing a filler, a cross-linking agent, a foaming agent and the like and then performing cross-linking can be mentioned. Other methods can also be used.

Examples of the filler used in the present invention include reinforcing materials such as carbon black, silica, clay, diatomaceous earth, talc and calcium carbonate. The amount of the filler is preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the polymer. If it is less than 0.1 part by weight, a sufficient reinforcing effect cannot be obtained.
If it exceeds 00 parts by weight, it loses its rubbery properties.

The cross-linking agent used in the present invention includes, for example, peroxides, polyols, polyamines and the like used for cross-linking vinylidene fluoride type fluorine rubber. Oxide), triallyl isocyanurate (TAIC),
Bisphenol AF, N, N'-dicinnamylidene-1,6
-Hexadiamine and the like. Crosslinker is polymer 100
0.1 to 10 parts by weight is preferable with respect to parts by weight. If it is less than 0.1 part by weight, the degree of crosslinking is insufficient, and if it exceeds 10 parts by weight, rubbery properties tend to be lost.

Examples of the foaming agent used in the present invention include dinitrosopentamethylenetetramine type, azodicarbonamide type, azobisformamide type, paratoluenesulfonyl hydrazide type and 4,4'-oxybis (benzenesulfonylhydrazide) type. Examples of commercially available products include cell microphones CAP, C, A, H, S (above, manufactured by Sankyo Kasei Co., Ltd.) and the like. Foaming agent is polymer 10
0 to 50 parts by weight, more preferably 5 to 30 parts by weight
Use parts by weight. If it is less than 1 part by weight, foaming becomes insufficient, and if it exceeds 50 parts by weight, molding is difficult. Further, a foaming aid can be used if necessary. Examples include urea-based Celton N, Celton NP, Celton MR (manufactured by Sankyo Kasei Co., Ltd.).

Further, if necessary, an organic tertiary or quaternary compound containing nitrogen or phosphorus as a crosslinking accelerator, a divalent metal oxide or hydroxide as an acid acceptor, and a crosslinking aid. A compound containing a plurality of vinyl groups or allyl groups can be used. In addition, compounding agents such as an antiaging agent, a processing aid, a scorch inhibitor, an antiozonant, an ultraviolet absorber, a flame retardant, and a plasticizer may be used if necessary.

The heat-resistant sponge rubber composition of the present invention is usually
It can be vulcanized at a temperature of 80 to 200 ° C., preferably 100 to 180 ° C., usually for 1 minute or longer, preferably for 3 to 60 minutes. If the vulcanization temperature is low, vulcanization and foaming will be insufficient, and if it is high, vulcanization will be fast and foaming will be insufficient. Further, if the vulcanization time is short, vulcanization and foaming are insufficient, and if the vulcanization time is long, physical properties are deteriorated due to deterioration.

The use of the heat resistant sponge rubber composition obtained by the present invention is not particularly limited, and examples thereof include the following. Automotive: cushioning material, shock absorber, silent block, bush, spring combination material, dust seal,
Various packing, bumpers, vehicles, transportation equipment: track pads, seismic resistant materials, oil resistant packing, rollers, solid tires, sound absorbing / vibrating parts, general machine parts: sound absorbing / vibrating parts, various packing, cushioning materials, installation parts, rolls , Electrical equipment: cushioning material, pad, suspension stand, anti-vibration rubber, various sealing materials, sound-damping and damping parts, camera / precision equipment: felt alternative material, cushioning material, anti-vibration rubber, shipbuilding: cushioning material, fender material , Crane buffers, Spinning equipment: Various cushioning materials, Bitcar buffers, protective materials,
Bush, chemical machine: cushioning material, washing ball, flange backing,
Silent block

[0021]

EXAMPLES Examples and comparative examples will be described below.
In addition, part and% show a weight part and weight%.

Example 1 Daier G801 / n-butyl acrylate (nBuA
c) / ethylene glycol dimethacrylate (1G) =
MT carbon in 100 parts of the mixture of 70/27/3 (weight ratio)
20 copies, TAIC (4 copies), Perhex 2.5B (1.5
Part), celmic CAP-250 (10 parts) and 140
Vulcanized at 30 ° C. for 30 minutes. Table 1 shows the foaming ratio, specific gravity and JIS A hardness of the obtained vulcanized product. In addition, DAI-EL G80
Fluorine-containing polymer 1 is iodine-containing vinylidene fluoride (2F) and hexafluoropropylene (6F)
Is a binary copolymer fluorine rubber.

Example 2 A vulcanized product was obtained in the same manner as in Example 1 except that the proportion of Celmic CAP-250 as a foaming agent was changed to 20 parts.

Comparative Example 1 A vulcanized product was obtained in the same manner as in Example 1 except that no blowing agent was used.

[0025]

[Table 1]

[0026]

INDUSTRIAL APPLICABILITY In the present invention, a heat-resistant sponge rubber composition having improved oil resistance, solvent resistance, heat resistance and low temperature characteristics can be obtained by utilizing the respective characteristics of the fluorine-containing polymer and the acrylic elastomer.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C08L 33/00 LJB 7921-4J 51/00 LKN 7142-4J // C08L 27:12 (72) Invention Yoshihiro Shirai 1-1, Nishiichitsuya, Settsu-shi, Osaka Prefecture Yodogawa Manufacturing Co., Ltd. (72) Inventor Etsushi Minamino 1-1, Nishiichitsuya, Settsu-shi, Osaka Prefecture Yodogawa Manufacturing Co., Ltd. (72) Inventor Tomoda Masayasu 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industrial Co., Ltd. Yodogawa Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. Filling with 100 parts by weight of a polymer obtained by dissolving or swelling an amorphous fluorine-containing polymer in an acrylic monomer and then subjecting this monomer to polymerization to polymerize it. Material 0.1 to 100 parts by weight, crosslinking agent 0.1 to 1
A heat-resistant sponge rubber composition comprising 0 parts by weight and 1 to 50 parts by weight of a foaming agent.