JPS61197646A - Blending oil for rubber - Google Patents

Abstract

PURPOSE:To provide the titled blending oil which imparts excellent modulus and tensile strength to rubber and hardly oozes out from rubber, by reacting a mercaptoalkoxysilane compd. with a liquid diene polymer. CONSTITUTION:A 4-12C diene (co)polymer having a number-average MW of 300-25,000 and contg. hydroxyl groups in a quantity of 0.1-10meq/g particularly at terminals obtd. by polymerizing a conjugated diene monomer in the presence of hydrogen peroxide in a liquid reaction medium with heating, or a liquid diene polymer which is a copolymer of said (co)polymer with an addition-polymerizable 2-22C alpha-olefin monomer is used. 10-5,000pts.wt. said diene (co)polymer or said liquid diene polymer is reacted with 100pts.wt. mercaptoalkoxysilane compd. of the formula (wherein R is a 1-5C alkyl; n is 1-30) such as gamma-mercaptopropylmethoxysilane in a non-reactive medium at 10-100 deg.C under a pressure of 1-10kg/cm<2>G for 0.1-10hr to obtain a blending oil for rubber. 5-200pts.wt. said blending oil is blended with 100pts.wt. natural or synthetic rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] 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. Also, in recent years,
Liquid polybutadiene, liquid polyisoprene, and those obtained by adding hydroxyl groups to these are 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 problems]

Therefore, the inventors of the present invention have conducted intensive 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 a mercaptoalkoxysilane compound and a 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:
R represents an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 1 to 30. ] This is a compound represented by Specific examples include mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, mercaptobutyltrimethoxysilane, and mercaptophenyltrimethoxysilane.

On the other hand, as the liquid diene polymer, there are no particular restrictions and various types can be used, but the number average molecular weight is 300 to 250.
00, preferably 500 to 10,000. 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 to 10 meq/g.

Among these, those in the range of 1.5 to 3.0 meq/g are preferred. These liquid diene polymers have 4 to 1 carbon atoms.
Examples include diene polymers and diene copolymers of No. 2, and copolymers of these diene monomers and α-olefinic addition polymerizable monomers having 2 to 22 carbon atoms. Specifically, butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer.

Examples include butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer, and the like. These liquid diene polymers are
For example, it can be produced by subjecting a conjugated diene monomer to a heating reaction in the presence of hydrogen peroxide in a liquid reaction medium.

The rubber compounding oil of the present invention consists of a reaction product of the above-mentioned mercaptoalkoxysilane compound and a liquid diene polymer. There are no particular restrictions on the conditions for reacting the two, but usually at a temperature of 10°C in a non-reactive solvent such as benzene.
~100°C, preferably 25-80°C, pressure 1-101
qr/aaG, preferably 0.0 at 1-5 kg/cdG.
The reaction may be carried out for 1 to 10 hours, preferably 0.5 to 5 hours. The blending ratio of both of the above compounds may be appropriately selected depending on various conditions, but generally 10 to 5000 parts by weight, preferably 100 to 5000 parts by weight of the liquid diene polymer is added to 100 parts by weight of the mercaptoalkoxysilane compound. 4
It should be determined within a range of 1,000 parts by weight. 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. (I
IR), etc.

When blending the rubber compounding oil of the present invention into the above-mentioned natural rubber or synthetic rubber, the amount to be blended is not particularly limited and may be adjusted as appropriate depending on the type of rubber, physical properties to be improved, etc.
Usually, 5 to 200 parts by weight of rubber compounding oil, preferably 10 to 1 part by weight, is added to 100 parts by weight of natural rubber or synthetic rubber.
It may be determined within a range of 0.00 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, sulfur.

Crosslinking agents (vulcanizing agents) such as organic sulfur compounds, metal oxides, and polyamines; Vulcanization accelerators such as aldehyde-amines, dithiocarbamates, guanidines, and sulfides;
Vulcanization accelerators such as metal oxides and fatty acids; amines and amine-aldehyde reactants.

Antiaging agents such as amine-ketone reactants and phenols;
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 mouth resin 5, coumaron-indene resin, and polybutene; dimethyl phthalate (DMP) , diethyl chloride (DEP),
Desirable agents such as dioctyl phthalate (DOP); process or extender oils such as paraffinic, naphthenic, and aromatic; lead sulfite, cadmium phosphite, zinc sulfite, barium phosphite, Stabilizers such as lead stearate, cadmium stearate, zinc stearate, barium stearate; calcium or magnesium reactants of flame-retardant azo dyes; colorants such as cadmium yellow, chrome yellow, phthalocyanine blue, titanium white; antimony oxide , inorganic flame retardants such as zirconium oxide and barium metaborate, or organic flame retardants such as phosphate esters; UV inhibitors such as benzophenone type (e.g. 2-hydroxybenzophenone), triazole type, salicylic acid derivative type, acrylonitrile derivative type etc. ; Phenol type (for example, antioxidants such as 2,6-di-t-butyl-p-cresol; antistatic agents such as surfactants); and the like.

〔Effect of the invention〕

By blending the rubber compounding oil of the present invention into rubber, particularly vulcanized rubber, as a process oil or extension oil, it is possible to significantly improve the mechanical strength, particularly tensile strength, modulus, etc. of the rubber. 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.

In other words, the rubber compounding oil of the present invention can be effectively used to improve the physical properties of rubber, particularly rubber used for tires and the like.

〔Example〕

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) 100 g was collected in a 200 ml separable flask and heated under vacuum at 80° C. and 1 mHg for 1 hour to dehydrate. Thereafter, the mixture was cooled to room temperature, and 5.0 g of γ-mercaptopropylmethoxysilane 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 is 1
It was sealed and stored in a 00cc glass container. The viscosity of this product was 5° poise/30°C.

(2) Production of vulcanized rubber The reaction product obtained in (1) above (rubber compounding oil) and the components shown in Table 1 are blended in predetermined amounts and kneaded at 45°C for 30 minutes using an internal mixing roll to form a rubber compound. A composition was obtained. 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 Example 1 (In 2>, 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.

*1: Styrene-butadiene rubber *2: Manufactured by Idemitsu Petrochemical Co., Ltd., number average molecular weight 2800°, hydroxyl group content 0.79 meq/g *3 Nioleum furnace black *4: Koka type flow tester *5: JIS K- Compliant with 6301 *6: Compliant with ASTM D-623. Using a flexometer (measurement conditions: 251b).

Claims (4)

[Claims] (1) A rubber compounding oil consisting of a reaction product of a mercaptoalkoxysilane compound and a liquid diene polymer. (2) The rubber compounding oil according to claim 1, wherein the liquid diene polymer contains a hydroxyl group. (3) The mercaptoalkoxysilane compound has the general formula S
H(CH_2)_nSi(OR)_3 [In the formula, R represents an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 1 to 30. ] The rubber compounding oil according to claim 1, which is represented by: (4) The rubber compounding oil according to claim 1, wherein 0.5 to 100 parts by weight of a liquid diene polymer is blended with 100 parts by weight of a mercaptoalkoxysilane compound.