JPH0576498B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a rubber compounding oil, and more particularly to a rubber compounding oil effective for improving the physical properties of vulcanized rubber. [Prior art and problems to be solved by the invention] Conventionally, paraffinic, naphthenic, or aromatic mineral oils have been used as process oils and extender oils that are blended into rubber as extenders, fillers, or softeners. Among them, aromatic mineral oils are often used. In addition, in recent years, liquid polybutadiene, liquid polyisoprene, and hydroxyl group-added oils have been known as so-called reactive process oils that react with rubber molecules and are difficult to leach out. However, these rubber compounding oils such as process oils and extension oils have room for improvement in the physical properties of vulcanized rubber, especially mechanical strength (especially tensile strength, modulus, etc.) and dynamic calorific value, and are used in tires. In this case, it was not completely satisfactory. [Means for Solving the Problems] Therefore, the present inventors have conducted extensive research in order to solve the problems of the prior art as described above and to develop an excellent rubber compounding oil. As a result, the inventors discovered that a reaction product between a specific silane compound and a liquid diene polymer has the desired physical properties, and completed the present invention. That is, the present invention provides a rubber compounding oil comprising a reaction product of 100 parts by weight of a mercaptoalkoxysilane compound and 10 to 5,000 parts by weight of a hydroxyl group-containing liquid diene polymer. Various mercaptoalkoxysilane compounds can be used as the mercaptoalkoxysilane compound used in the present invention, but they usually have the general formula SH(CH ₂ ) _o Si(OR) ₃ [wherein R
represents an alkyl group having 1 to 5 carbon atoms, and n is 1 to 30
indicates an integer. ] is a compound represented by Specific examples include mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptobutyltrimethoxysilane, and mercaptophenyltrimethoxysilane. On the other hand, the number average molecular weight of the hydroxyl group-containing liquid diene polymer is 300 to 25,000, preferably 500 to 25,000.
There are 10,000 examples. Particularly suitable are liquid diene polymers containing a hydroxyl group in the molecule, especially at the end of the molecule. Here, the hydroxyl group content is 0.1~
10meq/g is preferred. These liquid diene polymers include diene polymers and diene copolymers having 4 to 12 carbon atoms, and copolymers of these diene monomers and α-olefinic addition polymerizable monomers having 2 to 22 carbon atoms. There is. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer, and the like. These liquid diene polymers can be produced, for example, by subjecting a conjugated diene monomer to a heating reaction in a liquid reaction medium in the presence of hydrogen peroxide. The rubber compounding oil of the present invention consists of a reaction product of the above-mentioned mercaptoalkoxysilane compound and a hydroxyl group-containing liquid diene polymer. There are no particular restrictions on the conditions for reacting the two, but usually at a temperature of 10 to 100°C in a non-reactive solvent such as benzene.
The reaction may be carried out at a temperature of preferably 25 to 80°C and a pressure of 1 to 10 kg/cm ² G, preferably 1 to 5 kg/cm ² G for 0.1 to 10 hours, preferably 0.5 to 5 hours. Furthermore, the blending ratio of both of the above compounds should be determined in the range of 10 to 5,000 parts by weight, preferably 100 to 4,000 parts by weight of the hydroxyl group-containing liquid diene polymer to 100 parts by weight of the mercaptoalkoxysilane compound. be. The rubber compounding oil of the present invention thus obtained can be compounded into various natural rubbers or synthetic rubbers as process oils or extender oils.
Examples of this synthetic rubber include polybutadiene rubber (BR), polyisoprene rubber (IR), polychloroprene rubber (CR), polystyrene-butadiene rubber (SBR), polyacrylonitrile-butadiene rubber (NBR), and polyisobutylene-isoprene rubber. (IIR), etc. When blending the rubber compounding oil of the present invention with the above-mentioned natural rubber or synthetic rubber, there is no particular restriction on the blending amount, and it may be determined as appropriate depending on the type of rubber, physical properties to be improved, etc., but usually natural rubber Or add 5 to 200 parts of rubber compounding oil to 100 parts by weight of synthetic rubber.
It may be determined in parts by weight, preferably in the range of 10 to 100 parts by weight. Furthermore, when blending the rubber compounding oil of the present invention with the above-mentioned natural rubber or synthetic rubber, various additives can be added. Specifically, crosslinking agents (vulcanizing agents) such as sulfur, organic sulfur compounds, metal oxides, and polyamines; aldehyde-amines;
Vulcanization accelerators such as dithiocarbamates, guanidines, and sulfides; Vulcanization accelerators such as metal oxides and fatty acids; Antiaging agents such as amines, amine-aldehyde reactants, amine-ketone reactants, and phenols, etc. Reinforcing agents such as carbon black and white carbon; Fillers such as calcium carbonate, basic magnesium carbonate, diatomaceous earth, and clay; Tackifiers such as hydrogenated rosin, coumaron-indene resin, and polybutene; Dimethyl phthalate ( Plasticizers such as DMP), diethyl phthalate (DEP), and dioctyl phthalate (DOP); process or extension oils such as paraffinic, naphthenic, and aromatic; lead phosphite, cadmium phosphite, and zinc phosphite , barium phosphite, lead stearate, cadmium stearate, zinc stearate, barium stearate, and other stabilizers; calcium or magnesium reactants of flame-retardant azo dyes, cadmium yellow, chrome yellow, phtrocyanine blue, titanium white coloring agents such as; inorganic flame retardants such as antimony oxide, zircon oxide, barium metaborate, or organic flame retardants such as phosphate ester; benzophenone type (e.g. 2-hydroxybenzophenone etc.), triazole type,
UV inhibitors such as salicylic acid derivatives and acrylonitrile derivatives; phenolics (e.g. 2,
Examples include antioxidants such as 6-di-t-butyl-p-cresol; antistatic agents such as surfactants; and the like. [Effects of the Invention] The rubber compounding oil of the present invention can significantly improve the mechanical strength of rubber, especially tensile strength, modulus, etc., by blending it into rubber, especially vulcanized rubber, as a process oil or extension oil. . Furthermore, the dynamic calorific value of the rubber can be reduced.
Furthermore, since the rubber compounding oil of the present invention is a reactive compounding oil, it is difficult to leach out from the rubber, and from this point as well, the physical properties of the rubber can be favorably improved. Therefore, the rubber compounding oil of the present invention can be effectively used for improving the physical properties of rubber, particularly rubber used for tires and the like. [Examples] Next, the present invention will be explained in more detail based on Examples. Examples 1 and 2 (1) Rubber compounding oil Hydroxyl group-containing liquid polybutadiene (manufactured by Idemitsu Petrochemical Co., Ltd., number average molecular weight 2800, hydroxyl group content
0.79 meq/g) was collected in a 200 ml separable flask and heated under vacuum at 8° C. and 1 mmHg for 1 hour to dehydrate. After that, it was cooled to room temperature and γ-mercaptopropylmethoxysilane was added.
5.0g was added and mixed. Next, the temperature was raised to 80° C., heated and stirred for 3.5 hours, and then cooled to obtain a reaction product (rubber compounding oil). This was stored sealed in a 100 c.c. glass container. The viscosity of this thing is 50
Poise/It was 30℃. (2) Production of vulcanized rubber The reaction product obtained in (1) above (rubber compounding oil)
The components shown in Table 1 were blended in predetermined amounts and kneaded at 45° C. for 30 minutes using an internal mixing roll to obtain a rubber composition. This composition was press-vulcanized at 150° C. for 30 minutes to produce a vulcanized rubber. The physical properties of the obtained vulcanized rubber were measured and the results are shown in Table 1. Comparative Examples 1 to 3 In Example 1 (2), the reaction product (rubber compounding oil)
The same operation as in Example 1 (2) was carried out except that . The results are shown in Table 1.

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【table】

Claims (1)

[Scope of Claims] 1. A rubber compounding oil comprising a reaction product of 100 parts by weight of a mercaptoalkoxysilane compound and 10 to 5,000 parts by weight of a hydroxyl group-containing liquid diene polymer. 2 The mercaptoalkoxysilane compound has the general formula SH(CH ₂ ) _o Si(OR) ₃ [wherein R has 1 to 5 carbon atoms]
represents an alkyl group, and n represents an integer of 1 to 30. ]
The rubber compounding oil according to claim 1, which is represented by: