JP2003221452A - Rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a masterbatched rubber composition comprising a rubber clay nanocomposite in which a stratified sheet of an organic treated stratified clay mineral is uniformly and finely dispersed into the rubber. <P>SOLUTION: The masterbatching rubber composition comprises compounding a rubber of 100 pts.wt., carbon black of ≥80 pts.wt., and the stratified clay mineral of 1-50 pts.wt., the mineral being organic treated by ionic bonding of a secondary ammonium ion and/or a tertiary ammonium ion of ≥6C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition containing an organically modified layered clay mineral, more specifically, using a specific organically modified layered clay mineral and a predetermined amount of carbon black. The present invention relates to a masterbatch rubber composition in which a layered sheet of an organically treated layered clay mineral is uniformly finely dispersed.

[0002]

A rubber composition in which a layered sheet of a layered clay mineral is dispersed in rubber (Japanese Patent Publication No. 6-84456),
It is reported that the gas barrier property of such a rubber composition is improved (Japanese Patent Publication No. 8-510421). It has also been reported that the organized clay and rubber are kneaded with a process oil for rubber to uniformly disperse the clay in the rubber (JP-A-10-81).
785).

[0003]

DISCLOSURE OF THE INVENTION In the present invention, a masterbatch rubber composition comprising a rubber / clay nanocomposite in which a layered sheet of an organically treated layered clay mineral is uniformly finely dispersed in rubber is provided. The purpose is to get.

[0004]

According to the present invention, a rubber 1
1 part by weight to 50 parts by weight of carbon black, 80 parts by weight or more of carbon black, and 1 to 50 parts by weight of a layered clay mineral organized by ionic bonding of secondary ammonium ions and / or tertiary ammonium ions having 6 or more carbon atoms. A masterbatch rubber composition is provided.

Further, according to the present invention, there is provided the above-mentioned masterbatch rubber composition using 60 parts by weight or more of natural rubber per 100 parts by weight of rubber.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when kneading a clay mineral organically treated with a secondary ammonium ion and / or a tertiary ammonium ion and a rubber, 80 parts by weight or more of carbon black is added. It has been found that by masterbatching, a rubber / clay nanocomposite in which a layered sheet of clay mineral is finely dispersed can be formed. Further, it was also found that the rubber composition obtained by such a method exhibits the same scorch time as the rubber composition containing no organically modified clay mineral and maintains processability.

The organically treated layered clay mineral used in the present invention is organically treated by ionically bonding a secondary ammonium ion and / or a tertiary ammonium ion to the surface of a layered sheet constituting the clay mineral. Layered clay minerals are used. The quaternary ammonium ion is not preferable because the interlayer of the clay mineral does not spread to the extent that a rubber / clay nanocomposite can be formed, and the quaternary ammonium ion deteriorates the scorch of the obtained rubber composition. .

The secondary ammonium compound as an organic treating agent effectively used in the present invention includes dibutylammonium ion, dihexylammonium ion, dioctylammonium ion, didecylammonium ion,
Didodecyl ammonium ion, distearyl ammonium ion and the like are included, and the tertiary ammonium compound includes tributyl ammonium, trihexyl ammonium, trioctyl ammonium, tridecyl ammonium, tridodecyl ammonium, trioctadecyl ammonium, butyl dimethyl ammonium, Hexyl dimethyl ammonium, octyl dimethyl ammonium,
It includes decyldimethylammonium, dodecyldimethylammonium, octadecyldimethylammonium, didodecylmethylammonium, and the like.

Examples of the layered clay mineral used in the present invention include smectites such as montmorillonite, saponite, hydelite, nontorite, hectorite, and stevensite, vermiculite, halloysite, and the like, and either natural or synthetic is used. be able to. Also,
In the present invention, one or more of these layered clay minerals may be used.

The amount of the organically treated layered clay mineral effectively used in the present invention is 1 to 50 parts by weight, preferably 3 to 45 parts by weight. If the amount is less than 1 part by weight, the desired effect is not exhibited, and if it exceeds 50 parts by weight, the desired layered sheet of the organically modified layered clay mineral in rubber is uniformly obtained. Fine dispersion and scorch cannot be obtained.

The amount of carbon black to be effectively used in the present invention is 80 parts by weight or more, preferably 80 to 150 parts by weight, based on 100 parts by weight of rubber. If the amount is less than 80 parts by weight, the desired fine dispersion of the layered sheet of the organically treated layered clay mineral in rubber cannot be obtained.

The rubber used in the present invention includes natural rubber, synthetic rubber, thermoplastic elastomer or a mixture thereof. As the synthetic rubber, for example, isoprene rubber,
Chloroprene rubber, styrene rubber, nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, butyl rubber, epichlorohydrin rubber, acrylic rubber, urethane rubber, fluororubber, silicone rubber, styrene-butadiene copolymer rubber, ethylene-vinyl acetate rubber Chlorinated polyethylene and the like are used, and examples of the thermoplastic elastomer include 1,2-polybutadiene, styrene-butadiene block copolymer, styrene-isoprene block copolymer and the like. Since this rubber is a vulcanized rubber in a bulk state, it is preferable to use one having a molecular weight of 10,000 or more. Further, in the present invention, the fact that 60 parts by weight or more of the natural rubber is contained in 100 parts by weight of the whole rubber allows the clay mineral treated with the organic compound under high viscosity to be mixed and dispersed, and thus the dispersibility in rubber is further improved. It is preferable in that it can be further increased.

In addition to the above essential components, the rubber composition of the present invention further comprises a reinforcing agent such as carbon black or silica,
Vulcanizing or crosslinking agents, vulcanization or crosslinking accelerators, various oils, antioxidants, fillers, softeners, various compounding agents and additives to be added to general rubber compositions such as plasticizers may be added. The compounding amount of these compounding agents and additives can also be made into the general amount suitable for the use.

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but it goes without saying that the scope of the present invention is not limited to these Examples.

Organized lamellar clay mineral (organized clay
Preparation of Ray 1) Distearylamine (Pharmine D8 manufactured by Kao Corporation)
6) 58g and hydrochloric acid 12.4g were made to react in an isopropanol solution, and distearylamine hydrochloride was obtained. The obtained isopropanol solution of distearylamine hydrochloride was added at 95 ° C. to 100 g of a layered clay mineral Na-type montmorillonite (Kunipine F, manufactured by Kunimine Industries Co., Ltd.) dispersed in 3 L of water in advance. The layered clay mineral was organized by stirring at 95 ° C for 12 hours.
The obtained precipitate was filtered, washed with water, and then dried to obtain a clay mineral organically treated with distearyl ammonium ion.

Organized clay minerals (organized clay
Preparation of Ray 2) 43.8 g of didodecylmethylamine (Pharmine M2-2095 manufactured by Kao Corporation) was reacted with 12.4 g of hydrochloric acid in an isopropanol solution to obtain didodecylmethylamine hydrochloride. The obtained isopropanol solution of didodecylmethylamine hydrochloride was added at 95 ° C. to 100 g of a layered clay mineral Na-type montmorillonite (Kunipia F, manufactured by Kunimine Industries Co., Ltd.) previously dispersed in 3 L of water. The layered clay mineral was organized by stirring at 95 ° C for 12 hours. The obtained precipitate was filtered, washed with water, and dried to obtain a clay mineral organically treated with didodecylmethylammonium ion.

Organized clay minerals (organized clay minerals
Preparation of Ray 3) After adding 93.8 g of distearyldimethylammonium chloride (manufactured by Kao Corporation, Kotamin D86P, containing 75%) to 3 L of water, the temperature was adjusted to 80 ° C. 100 g of the layered clay mineral Na type montmorillonite (Kunipia F, manufactured by Kunimine Industries Co., Ltd.) was gradually added to this aqueous solution, and the layered clay mineral was organized by stirring at 80 ° C. for 5 hours. The obtained precipitate was filtered, washed with water, and then dried to obtain a clay mineral organically treated with distearyldimethylammonium ion.

Organically treated layered clay minerals and oil compounds
Preparation of coalesced (oil-treated organoclay) Organized clay 1 (20 g) and aroma oil (32 g) were added to a toluene solution, and the mixture was stirred at room temperature for 3 hours. An oil-treated organized clay was obtained by removing toluene.

The standard examples, Examples 1 and 2 and Comparative Examples 1 to 3 and each compounding agent were loaded into a Banbury mixer at a compounding ratio shown in Table 1 below, and sufficiently kneaded to obtain a master batch. A rubber sheet sample was obtained. The dispersibility of the layered clay mineral in the rubber sheet was confirmed by analyzing the sample of the obtained rubber sheet using an X-ray diffraction method. The case where the peak derived from the layered clay mineral disappeared by X-ray diffraction was evaluated as ◯, and the case where the peak derived from the layered clay mineral did not completely disappear and remained was evaluated as Δ.
Further, a part of the masterbatch rubber composition after the above kneading was subjected to a measurement sample of scorch time, and JIS K63
The time (minutes) for the clay to rise 5 points was measured at 125 ° C.

[0020]

[Table 1]

From the results in Table 1 above, as in Comparative Example 2,
Even in a mixture of an organically treated clay mineral and a process oil for rubber (oil-treated organic clay), rubber 1
Rubber in which layered sheet of clay mineral is finely dispersed unless carbon black is added in an amount of 80 parts by weight or more per 100 parts by weight
It can be seen that clay nanocomposites cannot be formed. On the other hand, as in Examples 1 and 2 of the present invention, the rubber 100
When 80 parts by weight of carbon black is blended per part by weight to form a masterbatch, a rubber / clay nanocomposite can be prepared even in a blending system in which a predetermined organically modified clay mineral and process oil for rubber are separately charged. It shows that formation and the desired scorch can be achieved. In addition, as in Examples 1 and 2 and Comparative Example 1, in the rubber composition containing the clay mineral organically treated with the secondary and tertiary ammonium ions, the quaternary ammonium ion was used as in Comparative Example 3. It can be seen that the scorch time is not shortened and the processability is maintained as compared with the rubber composition containing the layered clay mineral that has been organically treated.

[0022]

As described above, according to the present invention, the layered sheet of the layered clay mineral which has been organically treated is formed from the rubber / clay nanocomposite uniformly dispersed, and the scorch time is also desired. A masterbatch rubber composition is obtained.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoya Amino             2-1, Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd.             Ceremony Company Hiratsuka Factory F-term (reference) 4F070 AA07 AA08 AC27 AC45 AD06                       FB03                 4J002 AC011 AC021 AC061 AC071                       AC081 AC091 BB061 BB151                       BB181 BB241 BD141 BG041                       BP011 CH041 CK051 CP031                       DA036 DG047 DJ007 DJ047                       FB087

Claims (2)

[Claims] 1. Rubber 100 parts by weight, carbon black 8
Layered clay minerals 1 to 0 parts by weight or more and organically treated by ionic bonding of secondary ammonium ions and / or tertiary ammonium ions having 6 or more carbon atoms 1 to
A masterbatch rubber composition containing 50 parts by weight. 2. The masterbatch rubber composition according to claim 1, wherein the natural rubber is 60 parts by weight or more per 100 parts by weight of the rubber.