JPS63125541A - Flexible article - Google Patents

Abstract

PURPOSE:To obtain a flexible article excellent in heat, weathering and ozone resistances, by molding a composition based on a rubber composition containing a specified crosslinked rubber mixture and carbon black. CONSTITUTION:A flexible article based on a rubber composition comprising a crosslinked rubber containing rubber and carbon black, wherein said rubber component is based on a rubber composition comprising 5-95wt% organic rubber (A), 0-90wt% polyorganosiloxane (B) and 5-95wt% silicone-modified organic rubber (C) formed by modifying an organic rubber with a silicone compound containing Si-H groups in the molecule. The flexible articles are, for example, flexible rubber articles such as rubber hoses, rubber joints, vibration- proof rubbers, transmission belts and O-rings. The organic rubber used in component (C) is preferably the same organic rubber as component A or one having similar main chain structure.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a new flexible article made of rubber, specifically a rubber hose, a rubber joint, and a rubber gasket that have excellent heat resistance, ozone resistance, weather resistance, etc.

Anti-vibration rubber, shock absorbers, conveyor belts, transmission belts,
It relates to flexible articles such as rubber screens, rubber seals, O-rings, and rubber rolls.

BACKGROUND ART Conventionally, vulcanized products of ethylene-propylene-polydiene copolymer rubber have been mainly used as rubber compositions used in highly heat-resistant flexible articles.

Due to its rubber structure, the vulcanizate of ethylene-propylene-polydiene co-polymer rubber has excellent heat resistance, ozone resistance, chemical resistance, etc., and is also flexible, so it is susceptible to severe mechanical vibration. It is suitably used in radiator hoses, which are parts around automobile engines that are exposed to high-temperature atmospheres.

However, due to recent automobile exhaust gas regulations, combustion efficiency has improved, and engine temperatures have increased accordingly.The temperature around the engine, which used to be below 100°C, has increased to over 100°C, and radiator hoses, etc. Engine peripheral parts are now exposed to even higher temperatures than before.

Therefore, radiator hoses used around the engine are required to have even higher heat aging resistance.
It is difficult to satisfy these required characteristics with conventionally known ethylene-propylene-polydiene copolymer rubber vulcanizates, and it has not been possible to obtain sufficiently satisfactory articles.

Improvements in required characteristics such as these apply not only to radiator hoses, but also to all flexible rubber products used around automobile engines, such as various rubber hoses, gaskets, anti-vibration rubber, power transmission belts, rubber seals, and O-rings. This is true.

Furthermore, engine temperatures are likely to rise further in the future, and from this point of view, innovative flexible articles made of rubber are in great demand.

Similarly, in the category of industrial products, high-temperature properties are required for various flexible products. , rubber screens, rubber rolls, etc. are also required to have higher heat resistance.

On the other hand, as a vibration isolating material for a damper for supporting a cantilever of a pickup cartridge, etc., a rubber material having vibration damping properties such as butyl rubber has conventionally been used. Since the frequency of vibration of these butyl-based rubber vibration damping materials depends on temperature, the resonance point shifts significantly due to temperature changes, and the vibration damping effect changes greatly depending on temperature, so the temperature range in which they can be used is narrow. It had the disadvantage of being limited to

Therefore, there is a strong demand for heat resistance stability in such vibration damping materials as well.

Compared to conventional organic rubbers such as ethylene-propylene-polydiene copolymer rubber and butyl rubber, silicone rubber has much better heat resistance, weather resistance, and ozone resistance.
It has attracted attention in recent years because of its excellent mold releasability. However, although it has these advantages, silicone rubber has the disadvantage that it is inferior in fracture characteristics, water resistance, and hot water resistance compared to general organic rubber, that is, a rubber elastic body made mainly of carbon. I'm here.

The field of application of silicone rubber articles is also limited.

Therefore, various studies have been made to combine silicone rubber and organic rubber to obtain products that have the advantages of both.For example, as vibration-proof rubber materials, silicone rubber and polyisobutylene (especially Kaisho 54-419
However, since organic rubber and polyorganosiloxane (silicone rubber) originally have no affinity, organic rubber and polyorganosiloxane are extremely separated. It's easy. For this reason, conventionally proposed mixtures of organic rubber and polyorganosiloxane have extremely poor storage stability when unvulcanized, tend to have a negative impact on the quality and characteristics of bonded products, and are extremely difficult to manage. It was something. Moreover, the required properties can be satisfied.For example, it can be used as a vibration isolator.
It was not possible to obtain sufficient vibration isolation, frequency characteristics, and trace performance.

Therefore, we now have the advantages of both silicone rubber and organic rubber. It is expected that flexible articles made of rubber compositions with excellent heat resistance (heat resistance stability), weather resistance, ozone resistance, etc. will appear.

The present invention solves the above conventional problems and improves heat resistance, water resistance,
The object of the present invention is to provide a flexible article with excellent hot water resistance, weather resistance, ozone resistance, and fracture properties, which is made of crosslinked rubber containing rubber and carbon black, and the rubber component is (A) organic rubber. 5 to 95% by weight, (B) 70 to 90% by weight of polyorganosiloxa, and (C) 5 to 95% by weight of silicone-modified organic rubber obtained by modifying an organic rubber with a silicone compound containing an Si-H group in the molecule. It is characterized by having a rubber composition as a main component.

As a result of intensive studies to solve the above-mentioned conventional problems, the present inventors discovered that conventional polyorganosiloxane (
Many of the disadvantages of mixed rubber compositions of polyorganosiloxane (silicone rubber) and organic rubber are due to the solubility characteristics of polyorganosiloxane and organic rubber, or their incompatibility due to differences in polarity. We have completed the present invention by discovering that by using a polymer, organic rubber can be mixed with good dispersibility, and the stability after dispersion is also extremely high, and that even when polyorganosiloxane is mixed, it is well dispersed.

The present invention will be explained in detail below.

In the present invention, flexible articles include, for example, rubber hoses, rubber joints, gaskets, dampers for supporting the cantilever of pickup cartridges, vibration-proof rubber such as rubber sheets for turntables, transmission belts, rubber packings, O-rings, rubber conveyor belts, etc. Rubber screens, rubber rolls, etc. alone, or rubber and fibers,
Refers to flexible rubber products made in combination with metal, etc.

The flexible article of the present invention includes (A) 5 to 95% by weight of organic rubber, (B) 70 to 90% by weight of polyorganosiloxa, and (C) organic rubber in the molecule.
It is characterized in that the main component is a rubber composition consisting of 5 to 95% by weight of a silicone-modified organic rubber modified with a silicone compound containing an i-H group.

(A) Organic rubbers include natural rubber, in-prene rubber,
Styrene butadiene rubber, butadiene rubber, acrylonitrile butadiene rubber, ethylene-α olefin rubber, others, butyl rubber, halogenated butyl rubber, fluororubber, acrylic rubber, epichlorohydrin rubber, ethylene-vinyl acetate copolymer, ethylene-acrylate rubber,
Examples include polyurethane rubber.

In the present invention, when the flexible article formed from the rubber composition is a vibration-proof rubber, the organic rubber is butyl rubber, halogenated butyl rubber, or (a) a styrene content of 20% by weight or more and 45% by weight. less than 2, preferably 2
5 to 40% by weight of a styrene-butadiene copolymer, especially a styrene-butadiene copolymer having a butadiene 1.2 bond content of 20 to 60% by weight, and/or
(b) An acrylonitrile-butadiene copolymer having an acrylonitrile content of 25% by weight or more and less than 45% by weight, preferably 25 to 40% by weight is preferably used. (As will be described later, in the case of anti-vibration rubber, (B) polyorganosiloxane preferably accounts for 20 to 80% by weight, particularly preferably 30 to 65% by weight, of the total rubber component.) Particularly, in the present invention, When obtaining a heat-resistant shock absorber, (A) the organic rubber is (a) a styrene-butadiene copolymer having a styrene content of 45 to 75% by weight, preferably 50 to 60% by weight, and/or (b) Acrylonitrile content is 45 to 75% by weight, preferably 50 to 75% by weight
Acrylonitrile-butadiene copolymer and (C) butyl rubber (halogenated butyl rubber) having a content of 60% by weight are preferably used. (As will be described later, in the case of a heat-resistant shock absorber, (B) polyorganosiloxane is preferably at a proportion of 60% by weight or less, especially 30 to 50% by weight, in the total rubber component.) (A) Organic rubber is: In terms of uniform dispersibility with polyorganosiloxane and crosstalk workability, its Mooney viscosity M L
1÷4 is in the range of 20 to 150, preferably 30 to 100
A range of from 40 to 80 is particularly preferred. By using an organic rubber having such a viscosity as described above, a flexible article having stable quality and characteristics can be obtained. If the Mooney viscosity of the organic rubber is outside the above range, the kneading workability and dispersibility will deteriorate, making it difficult to maintain quality and properties.

In addition, (B) polyorganosiloxane has the general formula (where R and R' are hydrocarbon groups, and n represents an integer of 50 or more, R and R' may be the same or different. , ), the monovalent organic groups R and R' bonded to the silicon atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, Octyl group.

Alkyl groups such as nonyl group, decyl group, dodecyl group;
Aralkyl such as 2-phenylethyl group, 2-phenylpropyl group, l! i: Aryl group such as phenyl group, tolyl group, xylenyl group, t-butylphenyl group: and chloromethyl group, 3,3゜3-trifluoropropyl group, chlorophenyl group, fluorophenyl group, dichlorophenyl group, trichlorophenyl group Examples include substituted hydrocarbon groups such as C═C aliphatic double bond, vinyl group, allyl group,
Alkenyl groups such as 4-pentenyl group and 4-hexenyl group: ethylidenenorpornyl group.

Examples of these organic groups include, but are not limited to, alkylidenenorbornyl groups such as methylenenorbornyl groups, cycloalkenyl groups such as dicyclooctenyl groups, and dicyclopentenyl groups. , ease of synthesis and heat resistance as a polyorganosiloxane,
In order to provide properties such as weather resistance and mold releasability, methyl groups are preferably used in an amount of 60 mol% or more, more preferably 90 mol% or more.

(B) The degree of polymerization of the polyorganosiloxane, that is, n in the general formula (1) is 50 or more, preferably 2000 or more,
More preferably, it is 5000 or more.
If the degree of polymerization is less than 50, it will be difficult to reinforce with carbon black, and the workability during kneading will be poor.

The polyorganosiloxane (CB) used in the present invention is preferably substantially linear, but may have a partially branched or network structure.

In the present invention, in order to impart sufficient physical properties to the resulting rubber, the polyorganosiloxane is preferably crosslinked or co-crosslinked with an organic rubber to form a network structure.

Of course, in the present invention, sufficient effects can be obtained even when crosslinking or co-crosslinking is not performed.

In the case of crosslinking or co-crosslinking, the substituents R and R' of the polyorganosiloxane are 0.02 to 20 mol%,
Preferably 0.03 to 10 mol%, particularly preferably 0.03 to 10 mol%.
At least one or more C═C in the range of 05 to 5 mol%
It is necessary that the structure has an aliphatic double bond, especially when a crosslinking agent other than organic peroxide is used.

Preferably, the above-mentioned crosslinking substituent is such that it has a c=c aliphatic double bond via at least one carbon atom from the silicon atom of the siloxane. Further, the crosslinkable substituent preferably has five carbon atoms.

In addition, the silicone-modified organic rubber that is component (C) is an organic rubber, that is, a hydrocarbon polymer having a C=C double bond in the main chain, side chain, or terminal, and contains Si-H groups in the molecule. It is modified by a hydrosilylation reaction of a silicone compound.

The organic rubbers used as base materials for the silicone-modified organic rubber include natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, diene-based rubbers such as acrylonitrile-butadiene rubber, and ethylene-alpha rubbers such as ethylene-propylene diene rubber (EPDM). Other examples include olefin rubber 1, butyl rubber, halogenated butyl rubber, fluororubber, acrylic rubber, polyisobutylene having a terminal C═C double bond, and the like.

Among these, organic rubbers used for component (C) include (A) d! It is preferable to use one having the same or similar main chain structure as the organic rubber used as the organic rubber.

Also, S is used in the molecule to modify organic rubber.
As a silicone compound containing i-H3, 5t-
Although it is not limited as long as it has an H group,
A linear, branched, or cyclic polyorganohydrodiene siloxane is preferable, and the siloxane unit containing an Si-H bond is a terminal group, an intermediate group,
Any branched group may be used.

Monovalent organic groups bonded to the silicon atom of polyolga/hydrodiene siloxane include methyl group, ethyl group,
Alkyl groups such as propyl, butyl, pentyl, hexyl, octyl, and decyl; aralkyl groups such as 2-phenylethyl and 2-phenylpropyl; aryl groups such as phenyl; and chloro Examples include halogenated hydrocarbon groups such as methyl group, chlorophenyl group, and 3,3.3-)lifluoropropyl group, but the resulting flexible articles have various properties such as heat resistance and mold release properties. It is preferable that 90 mol% or more be methyl groups in order to provide the following properties.

In addition, examples of silicone compounds containing a 5t-H group include polysylmethylene in which the above-mentioned organic group and hydrogen atom are bonded to silicon atoms, and polysylethylene-siloxane copolymers.

Moreover, the weight average degree of polymerization of this silicone compound is 10 to
The range of 5000 is preferable, and the range of 50 to 3000 is particularly preferable, and the range of 90 to 1000 is particularly preferable.If the weight average degree of polymerization of the modified silicone compound is less than lθ, its performance as a compatibilizer may be extremely poor. Yes, 5000
If it exceeds this amount, not only is it difficult to synthesize, but it may also be substantially difficult to react with the organic rubber. Furthermore, the ratio of segments containing Si-H groups in the silicone compound [mX100/
(m+n)] is preferably 55% or less, particularly preferably 20% or less. If the 5f-H group ratio is too high, gelation may occur during the reaction, and the compatibilizing moiety may essentially disappear. be.

Furthermore, the organic rubber/silicone compound ratio in the silicone-modified organic rubber that is component (C) is preferably such that each segment unit ratio [XX 100/(X+Y)] is in the range of 0.1 to 60%, particularly 0.5 to 30%. A range of is preferred.

Here, X and Y are calculated from the following formula.

X=NX(m+n) N: Number of reacting silicone compounds n: Number of segments containing Si-H bonds n: Si-
Number of segments that do not contain H bonds Y = MXp M: Number of reacting organic rubbers p: Number of segments of organic rubber Whether the segment unit ratio [XX100/(X+Y)] is 0.1% or less or 60% or more, there is no compatibility. In some cases, solubility is not substantially exhibited.

This silicone-modified organic rubber is obtained by modifying the above-mentioned organic rubber 2 base material with the above-mentioned silicone compound by hydrosilylation.

In addition, a transition metal complex catalyst is required in the step of carrying out the hydrosilylation reaction.

Transition metal complex catalysts have already been published in the Journal of Organic Synthesis,
As reported in Vol. 28, p. 919 (1970), group II transition metal complexes selected from platinum, rhodium, cobalt, palladium, nickel, etc. are effectively used, but in particular chloroplatinic acid, platinum Metals, platinum-based catalysts such as activated carbon with platinum, platinum chloride and platinum olefin complexes are excellent. This hydrosilylation reaction starts at 30℃
Achieved at any temperature in the range of 150°C, but 60°C
It is more preferable to carry out the reaction at a temperature of 120 DEG C. to 120 DEG C. in order to suppress side reactions. The zero reaction is usually achieved within 6 hours, but as the molecular weight of the organic rubber increases, the reaction time needs to be increased. A solvent may not be used, but if it is used, inert solvents such as ethers, aliphatic hydrocarbons, aromatic hydrocarbons and halogenated hydrocarbons are suitable.

The rubber composition forming the rubber component in the present invention is (A
) 5 to 95 parts by weight of organic rubber, (B) 70 to 90 parts by weight of polyorganosiloxa, and (C) 95 to 5 parts by weight of silicone-modified organic rubber, whose composition ratio (weight ratio) is as follows: (A)/[(B)+(C)]=40
/ 60 to 9515 is preferable, and further (A) /
[(B)+(C)]=50/50~85/15
The range is more preferable.

In particular, when hot water resistance is required for flexible articles,
(A)/[(B)+(C)]=65745~95
15 is desirable.

If [(B) + (C)] is 66% or more, sufficient physical properties will not be obtained, and if r(B) + (C)] is 5% or less, sufficient heat resistance, weather resistance, and durability will not be obtained. It is difficult to obtain ozone properties.

In the present invention, examples of the vulcanizing agent used in the crosslinking or co-crosslinking reaction include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3゜3,4-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, and acetylacetone peroxide. oxide, 1,1-bis(t-
butylperoxy)3,3.5-)limethylcyclohexane, 1,1-bis(butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)octane, n-butyl-4゜4-bis(t-butylperoxy)valerate, 2.2-bis(t-butylperoxy)butane, t-butylhydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-methane hydroperoxide oxide, dicumyl peroxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, di-t-butyl peroxide, t
-Butylcumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2゜5
-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3-7 cetyl peroxide, acetyl peroxide, imbutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3.5-) lytylhexanoyl peroxide, sulfonic and peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide Trioyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, di-n-propyl peroxycarbonate, dimyristyl peroxydicarbonate, diallyl peroxydicarbonate, di-2-ethoxyethyl peroxy carbonate, dimethoxyisopropyl peroxycarbonate, di(3-methyl-3-methoxybutyl) peroxycarbonate, t-butyl peroxyacetate, t-butyl peroxyisobutyrate,
t-Butyl peroxy biparate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy-2-ethyl octanoate, t-butyl peroxy-3,5,5 -) to Limethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy) Xane, t-butylperoxymaleic acid, t-butylperoxyimprobyl capo, nate, cumyl peroxyoctanoate, t-hexyl peroxybivalate, t-butylperoxyneohexanoate, t - Organic peroxides such as hexylperoxyhexanoate, acetylcyclosulfonyl peroxide, t-butylperoxyallyl carbonate, sulfur, sulfur-like compounds, dipentamethylenethiuram tetrasulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide , thiuram compounds such as tetrabutylthiuram disulfide, 2-
Thiazole compounds such as (4-morpholino-dithio)benzothiazole, 4,4'-dithiol compounds, N, N
-4-thiobis(hexahydro-2H-7zebinone-2
), alkylphenol disulfide, sulfur donor exemplified by polymer polysulfide, p-quinone oxime, p'
, p'-dibenzoylquinone oxime, polynitrosobenzene, N-(2-methyl-2-nitrofurovir)
-Oxime and nitroso compounds exemplified by 4-nitrosoaniline, alkylphenol formaldehyde resins, heat-reactive phenol resins, melamine-formaldehyde condensates, triazine-formaldehyde condensates,
Examples include resin vulcanizing agents exemplified by halogenated alkylphenol/formaldehyde resins, dithiol compounds, polyamines, polyol metal oxides, and a wide range of crosslinking agents such as alkylphenol resins and quinoids.

In the present invention, the carbon black blended into the rubber composition forming the flexible article is preferably carbon black having an average particle diameter of 1000 angstroms or less, particularly 600 λ or less, as measured by an electron microscope. When the average particle diameter exceeds 1,000λ, it becomes difficult to obtain a reinforcing effect to develop sufficient physical properties.

Examples of carbon black having an average particle diameter of 1000λ or less include SRF, GPF, and HMF.

ACEF, FF, FEF, HAF, l5FF, SAF,
CF, SCF, XCF, EPC, MPC1HPC, CC
, GERMAN, Ketjen black, acetylene black, etc., but are not limited to these.

The amount of carbon black is the total amount of organic rubber, polyorganosiloxane, and silicone-modified organic rubber.
0 parts by weight, 2 to 200 parts by weight, preferably 5 to 1 parts by weight
00ii parts, more preferably 10 to 70 parts by weight. Even if the amount of carbon black is less than 2 parts by weight with respect to 100 parts by weight of the total amount of organic rubber, polyorganosiloxane and silicone-modified organic rubber, 200 parts by weight
Even if the amount exceeds 200 parts by weight, it is difficult to obtain a rubber composition with preferable physical properties, and if the amount exceeds 200 parts by weight, processing workability may deteriorate significantly.

Other fillers may be added to the rubber composition according to the present invention, if necessary. These fillers include fumed silica, precipitated silica, silica aerosol, crushed quartz, heavy calcium carbonate, light carbonate, chalk, chalk, magnesium-containing special carbonate, white oxide, magnesium carbonate, magnesite, kaolinite, Tea, tukaite, nakulanite, halloysite, hydrated halloysite, allophane, pyrophyllite, talc, montmorillonite, beidellite, hectorite, sabonite, nontronite, selinite, illite, muscovite, phlogopite, biotite, amesite, chamosite , cronstedite,
Hard clay, soft clay, kaolin clay, calcined clay, diatomaceous earth, gibbsite, beidellite, boehmite, diaspore, γ-alumina, α-alumina, barium carbonate, strontium carbonate, bentonite, whitebait, zinc white, zinc carbonate, zinc oxide, Activated clay, aluminum hydroxide (hysilite), titanium oxide, ferrite, asbestos, glass powder, aluminum silicate, red iron oxide, hydrotalcite, magnesium hydroxide, activated zinc white,
Inorganic compounds such as silicon carbide, silicon nitride, zirconium titanate, zirconium oxide, aluminum sulfate, calcium sulfate, barium sulfate, etc., and phenolic resins, coumaron resins, styrene resins, high styrene styrene-butadiene copolymers, nylon, aramid resins, etc. Examples include powders of organic compounds and single fibers. It is also possible to use fillers whose surfaces have been treated with an organic silicon compound, polydiorganosiloxane, etc. to make them hydrophobic.

In addition, other known heat resistance improvers, flame retardants, thermal conductivity imparting agents, vulcanization accelerators, vulcanization accelerators, processing aids, etc. may be added.

The flexible article of the present invention comprises (A) organic rubber 5 as described above.
~95 parts by weight, (B) polyorganosiloxa 70-90
parts by weight and (C) a rubber component consisting of 5 to 95 parts by weight of silicone-modified organic rubber, carbon black and a vulcanizing agent,
It is easily manufactured by adding reinforcing agents, processing aids, and other additives, and then heat curing and molding.

In particular, when obtaining a vibration-proof rubber in the present invention, (A) the above-mentioned (a) styrene-butadiene copolymer, (b) acrylonitrile-butadiene copolymer, (
C) Using butyl rubber alone or in a mixture, (a), (b)
) and (C), and the total amount of (B) polyorganosiloxane and (C) silicone-modified organic rubber [(B) + (c) 12 o to 80 parts by weight, preferably the above ( Total amount of a), (b) and (C) 70-35
parts by weight, and the total amount of (B) polyorganosiloxane and (C) silicone-modified organic rubber [CB) + (C) 130
By adding a rubber component consisting of ~65 parts by weight, carbon black, a vulcanizing agent, a reinforcing agent, a processing aid, and other additives, and heat curing and molding, a heat-resistant anti-vibration rubber with excellent anti-vibration properties is produced. Obtainable.

In addition, when obtaining a thermal shock absorbing material, (A) the above-mentioned (a) styrene-butadiene copolymer as the organic rubber, (b)
) acrylonitrile-butadiene copolymer, (C) butyl rubber (halogenated butyl rubber) alone or as a mixture, a total of 40 parts by weight or more of (a), (b) and (C), (B) polyorganosiloxane and (C) Total amount of silicone-modified organic rubber [(B) + (C) IS 0 parts by weight or less, preferably 50 to 70 parts by weight of the above (a), (b) and (C), and (B) Total amount of polyorganosiloxane and (C) silicone-modified organic rubber [(B) +
(C) A rubber component consisting of 130 to 50 parts by weight, and based on a total of 100 parts by weight of these rubber components, 30 to 300 parts by weight of a filler such as carbon black, 0 to 10 parts by weight of a vulcanizing agent, and 0 parts by weight of a blowing agent. By blending up to 10 parts by weight and curing with heat, it is possible to obtain a non-foamable or foamable thermal shock absorbing material having excellent shock absorbing properties with a rebound resilience of 30% or less.

The flexible article of the present invention has various excellent properties such as excellent heat resistance, hot water resistance, weather resistance, ozone resistance, and water resistance, as well as high mechanical strength, and It also has extremely good shock absorption properties.

Therefore, it can be applied to various rubber products, but because the temperature characteristics of vibration-proofing performance are stable, it is advantageous to apply it as a vibration-proofing rubber for shock absorption such as turntable rubber sheets and big-absorbing cartridges. It is.

υ The flexible article formed from the rubber composition mainly composed of (A) organic rubber, (B) polyorganosiloxane, and (C) silicone-modified organic rubber according to the present invention has 1 mechanical strength, heat resistance, and weather resistance. The physical properties such as hardness, ozone resistance, water resistance, hot water resistance, and durability are extremely superior to those made of a simple mixture of organic rubber and polyorganosiloxane (silicone rubber). This is because the silicone-modified organic rubber of the present invention exhibits a strong affinity for both organic rubber and polyorganosiloxane and acts as a so-called compatibilizer, resulting in stability not found in conventional organic rubber-polyorganosiloxane compositions. Depends on what you can do.

Further, even a combination of only an organic rubber and a silicone-modified organic rubber can improve heat resistance and provide stability not found in conventional organic rubber-polyorganosiloxane compositions.

[Examples] The present invention will be described in more detail below with reference to Examples and Comparative Examples; however, the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, prior to each individual explanation, the silicone-modified organic rubber used in the present invention and its production example will be explained.

[Manufacturing Example 1] The hair is a 20 wt% chloroform solution of butyl rubber with an average molecular weight of 500,000 and an unsaturation degree of 2.0%. it'll
was placed in a pressure-resistant glass reaction vessel purged with nitrogen.

Subsequently, under a nitrogen atmosphere, 80 parts by weight of linear polymethylhydrodiene siloxane with a polymerization degree of 150.3i-H group ratio of 10% and 0.005 parts by weight of platinum Φ ethylene complex were added to the chloroform solution of this butyl rubber, and chloroform was added. After the reaction was completed under reflux conditions with stirring for 4 hours, the reaction vessel was added to a large excess of methanol solution and solidified to obtain crude silicone-modified butyl rubber. A silicone-modified butyl rubber was produced by dissolving this crude silicone-modified butyl rubber again in chloroform and repeating the procedure of reprecipitating with methanol twice, followed by vacuum drying.

[Production Example 2] Based on the same operation as Production Example 1, the weight average molecular weight was 160,000,
Chloroform solution of EPDM with 3.5% unsaturation SOO
Weight part 1 degree of polymerization 50. Silicone-modified EPDM was produced using 80 parts by weight of a linear polymethylhydrodiene siloxane with a Si-H group ratio of 10% and 0.005 parts by weight of a platinum/ethylene complex.

[Production Example 3] Based on the same operation as Production Example 1, 500 parts by weight of a chloroform solution of a styrene-butadiene copolymer (SUR) with a weight average molecular weight of 200,000, containing 46% styrene, 13% vinyl in the butadiene portion, and a degree of polymerization of 50. ．． A silicone-modified SBR was produced using 80 parts by weight of a linear polydimethylhydrodiene siloxane with a Si-H group ratio of 10% and 0.005 parts by weight of a platinum/ethylene complex.

[Example 1.2 and Comparative Examples 1 to 3] The raw materials having the compositions shown in Table 1 were molded at a vulcanization temperature of 170° C. to produce rubber hoses as shown in FIGS. 1 and 2.

That is, in the rubber hose shown in FIG. 1, the vulcanized rubber part l and the fiber cloth part 2 made of synthetic fiber or natural fiber are cylindrical! The rubber hose shown in Figure 2 has an R layer, and the vulcanized rubber part is 3.5 m! I
This is a rubber hose laminated in a cylindrical shape on the inner and outer layers of the fabric portion 4.

DIN No. 3 dumbbells were punched out from the vulcanized rubber portion of this rubber hose, and their various properties were measured. The results are shown in Table 1.

(Margin below) Table 1 Note that in Table 1, *1 to *13 are as follows.

*1: Polydiorganosiloxane with a degree of polymerization of 6000 and 0.1 mol% of organic groups bonded to silicon atoms being vinyl groups and the remainder being methyl groups *2: JSREP57C *3: Silicone-modified butyl rubber obtained in Production Example 1 * 42 Geast S manufactured by Tokai Carbon Co., Ltd. (average particle size 150) *5: FEF black *6: 2,5-dimethyl-2,5-di-t-butylperoxyhexane diluted with polydimethylsiloxane, Organic peroxide content 50% *7: Observation results after leaving it for 24 hours after kneading.
Observation results after stimulation with time ultrasound *8: Tensile speed 300ms/sin (D I N 3
), breaking strength Tb (Kg/cm2) at break point at 25°C *9: elongation at break Eb (%) at break point of *8 *10
: Hardness Hs according to JIS K2SO3 (JIS A
) *ll: While open, after heat treatment at 160℃ for 7 days *Change rate (%) determined by the following formula and measured under the same conditions as in *8 Tb+ Tbl : Value determined from *8 and *9 Tb2: After heat treatment Value br Ebx: Value determined by *8, *9 Eb2: Value after heat treatment *12: Hot water treated at 180°C for 15 hours using an autoclave, measured under the same conditions as *8, and determined using the above formula Rate of change (%) (hereinafter blank) From Table 1, the rubber composition according to the present invention has no separation of organic rubber and polyorganosiloxane, has excellent processing workability and quality stability, and It is clear that the rubber hose obtained by this method has extremely excellent heat resistance and hot water resistance.

[Examples 3 and 4 and Comparative Examples 4 to 6] The raw materials having the composition shown in Table 2 were heated and molded at a vulcanization temperature of 170°C to form a toothed belt as shown in Fig. 3 and a toothed belt as shown in Fig. 4. A V-belt and a conveyor belt (not shown) were vulcanized and molded.

In FIGS. 3 and 4, 11 is a tooth, 12 is a holding rubber layer, 13 is a cord, 14 is an outer cover layer made of vulcanized rubber, and 15 is an adhesive rubber layer.

DINS dumbbells were punched out from the vulcanized rubber portions of these belts, and their various properties were measured. The results are shown in Table 2.

(Margin below) Table 2 Note that in Table i2, polyorganosiloxane-1° carbon black-1, carbon black-2, and organic peroxide are the same as those in Table 1, and the initial physical properties and heat resistance are the same as those in Table 1. The methods for measuring the properties and hot water resistance are also the same. Other *a to *d are as follows.

*a: JsREPII *b: R3s No. 1 *C: Silicone modified E PDM obtained in Production Example 2 *d:
The number of generated cracks is indicated in alphabetical order as the 0 judgment standard determined by a static ozone test using static ozone 100p100pph℃ x 40% stretch for 48 hours, where A is a small number, B is a large number, and C is an innumerable number of cracks. This indicates that a crack has occurred, and also indicates the size of the crack that has occurred.

1 can be confirmed with a 10x magnifying glass, 2 can be confirmed with the naked eye,
3 is crack less than 1mm, 4 is crack 1-3mm, 5 is 3m
Cracks of m or more are shown respectively.

From Table 2, it is clear that the flexible article of the present invention has excellent heat resistance, hot water resistance, and weather resistance. Although this example shows an example in which the outer cover layer of a belt is prepared according to the present invention, it goes without saying that the present invention can also be applied to the holding rubber layer 12 shown in FIGS. 3 and 4.

Further, the present invention can be similarly applied to O-rings, rubber rolls, gaskets, rubber packings, etc.

[Examples 5 to 7 and Comparative Examples 7 to 101 After mixing the raw materials in the formulations shown in Table 3 (A) and (B) in a rubber mixer at a container internal temperature of 80°C.

Form into a sheet with a roll with a surface temperature of 50℃, and then
Filled into a 10x0.1cm mold and weighed 50Kg/cm
After heating and pressurizing at 2,170°C for 10 to 15 minutes, the mold was demolded.

From the obtained sheet, punch out DINS dumbbells,
Its properties were measured in the same manner as in Tables 1 and 2. The results are shown in Table 3 (A) and Table 3 (B).

Table 3 (A) Table 3 (B) Note that zeros a-k in Table 3 are as follows.

Book A: Polydiorganosiloxane with degree of polymerization s, ooo, 0.25 mol% of the organic groups bonded to silicon atoms are vinyl groups and the remainder are methyl groups Book B: R5s No. 1 Book C: 35% bonded styrene, butadiene 1.2 bond 40
%, ML1+4 = 52 SBR book d: 40% bound styrene, 40% butadiene 1.2 bound, M L l◆
4=50 SBR book e: Polysar bromobutyl Book i: Dynamic spring constant (E' - η2) and static shear modulus (Gs) (
7) Ratio: E'mηz/Gs (the smaller the better) Book J: Loss tangent 20℃, 15Hc (larger rod is better) Zero = low temperature torsion test, temperature at which the specific modulus becomes 2 (
(The lower the better) From Table 3 (A), the rubber sheet according to the present invention has no separation of organic rubber and polyorganosiloxane, has good processing workability, 5 quality stability, and has good breaking strength, heat resistance, and heat resistance. It is highly water-based, has good static-dynamic ratio and tan δ, and has excellent properties as a vibration-proof rubber. Furthermore, due to the influence of polyorganosiloxane, the temperature characteristics of vibration-proof performance are also extremely stable. .

Therefore, it is clear that the rubber sheet for turntables and the vibration-proof rubber for acoustics such as pickup cartridges according to the present invention have extremely excellent performance.

[Examples 8 to 10 and Comparative Examples 11 and 12] Rubber sheets were molded in the same manner as in Examples 5 to 7, except that the raw materials with the formulations shown in Table 4 were used, and the resulting sheets had DIN3
Table 4 shows the results of punching out dumbbells and measuring various objects.

Table 4 In Table 4, polyorganosiloxane-2, natural rubber and carbon black-1 are the same as those in Table 3, and the other numbers 1 to 6 are as follows.

☆1: Styrene 60% ☆2: 7Crylonitrile 60% ☆3: Silicone-modified SBR according to Production Example 3 ☆4: 2,
5-dimethyl-2,5-diE-butylperoxyhexane diluted with polydimethylsiloxane, organic peroxide content 50% ☆5 Mixture of dinitrosopentamethylenetetramine and urea ☆6: Danlop trypso Table 4 shows that the rubber sheet according to the present invention has excellent breaking strength and heat resistance, has no separation of organic rubber and silicone rubber, and has good processability and quality stability. The elasticity measurement results show that it has high impact absorption properties, and due to the influence of polyorganosiloxane, it has excellent ozone resistance and weather resistance.

Therefore, it is clear that an excellent shock absorbing material can be obtained by the present invention. Furthermore, this effect is similarly exhibited in the foamed material (Example 10).

Effects of the Invention As detailed above, the flexible article of the present invention utilizes the property that silicone-modified organic rubber is compatible with organic rubber and also acts as a compatibilizer between organic rubber and polyorganosiloxane. Not only is silicone-modified organic rubber itself effective in modifying organic rubber, but it also allows extremely stable mixing of organic rubber and polyorganosiloxane.

Therefore, the rubber composition forming the flexible article of the present invention is
There is no separation of polyorganosiloxane and organic rubber, and it has excellent quality stability and processing workability.

Moreover, the obtained article has extremely high strength, and is excellent in durability, heat resistance, water resistance, hot water resistance, ozone resistance, and weather resistance.

Furthermore, the flexible article according to the present invention has an excellent 1f11! This shock absorption property is extremely thermally stable.

Therefore, the +4-polymerized article of Kizari 1 is extremely useful as various rubber products, and especially when used as a vibration-proof material, it can exhibit excellent effects over a wide range of temperatures and is extremely advantageous industrially.

[Brief explanation of the drawing]

Figure f51 and Figure 2 are for Example 1.2 and Comparative Examples 1 to 3.
3 and 4 show the belts made in Example 3 and Comparative Examples 4 to 6, and FIG. 3 is a longitudinal sectional view of the toothed belt, and FIG. The figure is a cross-sectional view of the V-belt.

Claims (1)

[Scope of Claims] Consisting of a crosslinked rubber containing rubber and carbon black, the rubber component is (A) organic rubber 5 to 95% by weight (B) polyorganosiloxane 0 to 90% by weight (C)
A flexible article characterized in that the main component is a rubber composition comprising 5 to 95% by weight of a silicone-modified organic rubber obtained by modifying an organic rubber with a silicone compound containing an Si-H group in the molecule.