JPH0726025A - Rubber-chemical masterbatch blend composition - Google Patents

Abstract

PURPOSE:To reduce tackiness to improve roll processibility and to prevent degradation in rubber elasticity after vulcanization by compounding a rubber chemical, a rubber, and a specific liq. fatty acid or a specific organic unsatd. fatty acid. CONSTITUTION:The compsn. is prepd. by compounding 50-90 pts.wt. rubber chemical such as a vulcanizing agent, an accelerator, an antioxidant, an activator, a scorch retarder, or a filler, 10-50 pts.wt. rubber such as a natural rubber, a synthetic rubber, or their blend, and 1-30 pts.wt. 8-20C liq. fatty acid having a viscosity at 80 deg.C of 100cP or lower (e.g. oleic acid, linolic acid, linolenic acid, or tall oil fatty acid) or 0.1-20 pts.wt. organic unsatd. fatty acid having at least two C-C double bonds in the molecules having a least 10wt.% conjugated dienoic acid having at least one pair of two conjugated C-C double bonds (e.g. 9,11-octadecadienoic acid).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a chemical masterbatch compounding agent composition for rubber.

[0002]

2. Description of the Related Art Generally, many chemicals for rubber are in the form of fine powder, so they are dusted and scattered to cause a decrease in measurement accuracy, or they adhere to an operator to irritate or inhale the skin. It may enter the body and is not good for hygiene. Therefore, in the rubber product manufacturing industry, a so-called masterbatch system is adopted in which a chemical for rubber is kneaded into rubber in advance and predispersed. This masterbatch system has no scattering properties and is excellent in dispersibility in rubber, and thus it is easy to mix it with rubber even in the case of the above-mentioned problematic rubber chemicals.

As a technique related to a chemical masterbatch for rubber, Japanese Patent Laid-Open No. 223130/1990 discloses a rubber compounding agent comprising three components of a chemical for rubber, rubber and ethylene-vinyl acetate copolymer, and oils. A composition has been proposed, but depending on the type of rubber chemical or the composition ratio of the three components, the composition may become sticky and cause problems in processing or storage of the composition. For example,
In the case of producing a plate-shaped masterbatch, the sheet is put out by a roll, and at this time, if the composition has a high tackiness,
There is a problem that a sheet is stuck on the surface of the roll, the releasability is bad, and the workability is significantly impaired.

On the other hand, in Japanese Unexamined Patent Publication No. 53-41342, rubber is selected as a binder and process oil for rubber is selected as an oil when a masterbatch is produced with a composition comprising rubber and a vulcanization accelerator. However, there is no mention of preventing tackiness of the masterbatch itself. In addition, JP-A-6
In JP-A 2-201947, oil in which rubber is dissolved is mixed with an additive for rubber, but nothing is mentioned about prevention of tackiness of the composition.

Further, as a technique relating to a chemical masterbatch for rubber, Japanese Patent Application No. 2-312153 discloses a chemical for rubber, a rubber and an ethylene-vinyl acetate copolymer (EV).
A rubber compounding composition comprising four components of A), a fatty acid such as stearic acid, and oils has been proposed. In this rubber compounding agent composition, the rubber acts as a binder, the fatty acid prevents the viscosity of the composition, and the oils lower the viscosity of the rubber. However, in this rubber compounding agent composition, since oil is an essential component, there is a problem that adhesion to a roll occurs, roll workability deteriorates, and the rubber elastic modulus after vulcanization decreases. is there.

[0006]

The object of the present invention is to solve the above-mentioned problems, namely to maintain a good shape which is the original purpose of the masterbatch and to impair the good dispersibility in rubber. It is an object of the present invention to provide a chemical masterbatch compounding agent composition for rubber that prevents the tackiness of the composition to improve the roll workability and does not reduce the rubber elastic modulus after vulcanization.

[0007]

Means for Solving the Problems The inventors of the present invention have made extensive studies in order to solve the above-mentioned problems, and as a result, have formulated a rubber chemical masterbatch composition composition for the above-mentioned purpose by blending a specific fatty acid. It succeeded in obtaining it and came to complete the present invention. That is, the chemical masterbatch compounding agent composition for rubber of the first invention of the present invention has the following (a) to
(C) Component. (A) Chemicals for rubber 50 to 90 parts by weight (b) Rubber 10 to 50 parts by weight (c) Liquid fatty acid having 8 to 20 carbon atoms and having a viscosity of 100 cps or less at 80 ° C. 1 to 30 parts by weight Second The rubber chemical masterbatch compounding agent composition of the invention is
It comprises the following components (a), (b) and (d). (A) Chemicals for rubber 50 to 90 parts by weight (b) Rubber 10 to 50 parts by weight (d) Molecules containing at least one set of two carbon-carbon double bonds in a conjugated relationship Conjugated dienoic acid 10% by weight Organic unsaturated fatty acid containing two or more carbon-carbon double bonds in the contained molecule 0.1 to 20 parts by weight

The contents of the present invention will be described below. As the rubber chemicals used in the first invention and the second invention of the present invention,
For example, vulcanizing agent, vulcanization accelerator, antioxidant, vulcanization aid,
Examples include scorch agents and fillers. The amount of the rubber chemical compounded is 50 to 90 parts by weight. If the compounding amount of the rubber chemicals is less than 50 parts by weight, it will be deviated from the intended use of the rubber article, and if it exceeds 90 parts by weight, the content of the other components serving as the binder will be too small and the shape will be unstable, which is preferable. Absent.

Examples of the rubber used in the first and second inventions of the present invention include natural rubber (NR) and / or styrene-butadiene rubber (SBR) and butylene rubber (B).
R), ethylene-propylene-diene terpolymer rubber (EPDM) and other synthetic rubbers, or a mixture thereof. The amount of rubber compounded is 10 to 50 parts by weight. If the amount is less than 10 parts by weight, the tackiness of the masterbatch after mixing is large, so that the sheet cannot be taken out by a roll, and if it exceeds 50 parts by weight, the dispersibility of the fatty acid of the present invention is deteriorated Absent.

As the liquid fatty acid having a viscosity of 100 cps or less at 25 ° C. and a carbon number of 8 to 20 used in the first invention of the present invention, for example, oleic acid, linoleic acid, linoleic acid, tall oil fatty acid and the like are used. be able to. If the viscosity of the liquid fatty acid at 80 ° C. exceeds 100 cps, the shape of the masterbatch becomes unstable, which is not preferable. Further, if the liquid fatty acid has a carbon number other than 8 to 20, it is not preferable because the breaking property of the rubber is deteriorated. The liquid fatty acid content is 1 to 30 parts by weight. If the amount of the liquid fatty acid is less than 1 part by weight, the effect of preventing adhesion cannot be exhibited, and
If it exceeds 30 parts by weight, the shape of the masterbatch becomes unstable, which is not preferable.

The organic unsaturated fatty acid used in the second invention of the present invention is a molecule containing at least 10% by weight of a conjugated dienoic acid containing at least one pair of two carbon-carbon double bonds having a conjugated relationship in the molecule. It is an organic unsaturated fatty acid containing two or more carbon-carbon double bonds. The above-mentioned “conjugated dienoic acid” refers to an organic unsaturated monocarboxylic acid containing at least one set of two carbon-carbon double bonds having a conjugated relationship in its molecule, and the carbon-carbon double bond having a conjugated relationship is one. A set of two sets is preferable, but there may be two or more sets. The organic unsaturated fatty acid containing two or more carbon-carbon double bonds in the molecule containing 10% by weight or more of the conjugated dienoic acid (hereinafter, simply referred to as organic unsaturated fatty acid) naturally contains the conjugated dienoic acid, but otherwise. The organic unsaturated fatty acid of 2 contains two or more carbon-carbon double bonds, but they are different from each other in that they are not in a conjugation relationship with each other.

The content of the conjugated dienoic acid in the organic unsaturated fatty acid must be 10% by weight or more, preferably 25% by weight or more, and 100% by weight, that is, the organic unsaturated fatty acid is all conjugated dienoic acid. May be. When the content of the conjugated dienoic acid is less than 10% by weight, the rubber elastic modulus after vulcanization is lowered, which is not preferable.

Examples of the conjugated dienoic acid include 2,4-
Pentadienoic acid, 2,4-hexadienoic acid, 2,4-decadienoic acid, 2,4-dodecadienoic acid, 9,11-octadecadienoic acid, α-eriostearic acid, 9,11,
13,15-octadecatetraenoic acid, 9,11,13
-Octadecatrienoic acid and the like.

Preferred examples of organic unsaturated fatty acids include:
Examples include dehydrated castor oil fatty acids. This dehydrated castor oil fatty acid is obtained by dehydrating castor oil. The content of the conjugated dienoic acid can be changed depending on the dehydration method, and for example, 35% by weight and 60% by weight can be obtained. In the case of this dehydrated castor oil fatty acid, the conjugated dienoic acid is 9,
11-Octadecadienoic acid is the main, other organic unsaturated fatty acids mainly contain non-conjugated octadecadienoic acid, and other examples include linoleic acid and linoleic acid. Further, in the present invention, in addition to the dehydrated castor oil fatty acid,
Conventionally used fatty acids represented by stearic acid may be used in combination.

The organic unsaturated fatty acid is a total unsaturated fatty acid,
It is desirable that the unsaturated fatty acid having a long-chain alkyl group having 10 to 22, preferably 12 to 22 carbon atoms is contained in an amount of 75% or more. When the carbon number is 10 to 22, the effect of the present invention can be further improved. Further, the degree of unsaturation of all unsaturated fatty acids is preferably 130 or more in terms of iodine value. The iodine value of 130 or more can further improve the effects of the present invention.

In the rubber chemical masterbatch compounding agent composition of the first and second inventions of the present invention, if necessary, roll workability is deteriorated and the rubber elastic modulus after vulcanization is lowered. Oils such as naphthenic oils can be blended within the range not present.

[0017]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Examples 1 to 8 and Comparative Examples 1 to 7) Table 1 below
According to the compounding recipe (compounding unit: parts by weight), each of the rubber chemical masterbatch compounding agent compositions was prepared. Then
Each rubber chemical masterbatch compounding agent composition corresponding to 8 parts by weight of zinc white was added to the following basic compounding rubber composition A and kneaded with a Banbury mixer to prepare various rubber compositions, and roll workability and Rubber elastic modulus after vulcanization (1
00% modulus, index display) was evaluated.

[Basic compounded rubber composition A] Natural rubber 100 parts by weight Carbon black (HAF) 60 parts by weight Sulfur 6 parts by weight Vulcanization accelerator (N ′, N′-dicyclohexyl-2-benzothiazolyl sulfenamide) 0.8 parts by weight

(Examples 9 to 13 and Comparative Examples 8 to 12) According to the compounding recipe (compounding unit: parts by weight) of Table 2 below, respective chemical masterbatch compounding agent compositions for rubber were prepared. Next, each rubber chemical masterbatch compounding agent composition corresponding to 6 parts by weight of sulfur was added to the following basic compounding rubber composition B,
Various rubber compositions were prepared by kneading with a Banbury mixer, and the roll workability and the rubber elastic modulus after vulcanization (100% modulus, index display) were evaluated. [Basic compounded rubber composition B] Natural rubber 100 parts by weight Carbon black (HAF) 60 parts by weight Zinc white 10 parts by weight Vulcanization accelerator (N ', N'-dicyclohexyl-2-benzothiazolyl sulfenamide) 0. 8 parts by weight

Roll workability and elastic modulus after vulcanization were measured and evaluated by the following methods. (1) Roll workability (roll adhesion) ◯: good (low tackiness) x: poor (stickiness) (2) elastic modulus after vulcanization (100% modulus, index display) Evaluated according to JIS K6301 . The 100% modulus (kg / cm ² ) of Comparative Example 8 was set as 100, and the result was expressed as an index.

[0022]

[Table 1]

[0023]

[Table 2]

From the results shown in Tables 1 and 2, the following was found. In the rubber chemical masterbatch compounding agent compositions of Examples 1 to 13 using the liquid fatty acid or the organic unsaturated fatty acid defined in the present invention, both roll workability and elastic modulus after vulcanization were good. . On the other hand, Comparative Examples 1 to 3, 5, 6, 8, 9, 11, 12 using naphthenic oil
The rubber chemical masterbatch compounding agent composition of, or Comparative Examples 3, 4, 7 in which the compounding amount of the liquid fatty acid or the organic unsaturated fatty acid specified in the present invention is not included in the scope of the present invention.
Nos. 9, 19, and 12 were poor in roll workability and elastic modulus after vulcanization.

[0025]

According to the present invention, the viscosity of the masterbatch can be improved by using liquid fatty acid or organic unsaturated fatty acid instead of the oil which causes the adhesion to the roll and lowers the rubber elastic modulus after vulcanization. And a chemical masterbatch compounding agent composition for rubber, which can prevent the composition from sticking and prevent the rubber elastic modulus after vulcanization from decreasing.

Claims (2)

[Claims] 1. A chemical masterbatch compounding agent composition for rubber comprising the following components (a) to (c): (A) Chemicals for rubber 50 to 90 parts by weight (b) Rubber 10 to 50 parts by weight (c) Liquid fatty acid having 8 to 20 carbon atoms and having a viscosity of 100 cps or less at 80 ° C. 1 to 30 parts by weight 2. A chemical masterbatch compounding agent composition for rubber comprising the following components (a), (b) and (d). (A) Chemicals for rubber 50 to 90 parts by weight (b) Rubber 10 to 50 parts by weight (d) Molecules containing at least one set of two carbon-carbon double bonds in a conjugated relationship Conjugated dienoic acid 10% by weight Organic unsaturated fatty acid containing two or more carbon-carbon double bonds in the contained molecule 0.1 to 20 parts by weight