JPS6038457A - Urethane rubber composition - Google Patents

Abstract

PURPOSE:To provide a urethane rubber compsn. which has excellent rubber processability, gives vulcanized rubber having excellent hardness, resilience, etc., and is suitable for use as a material for the production of rubber rolls, by blending a melamine resin in a specified weight ratio with an unvulcanized urethane rubber contg. carbon black. CONSTITUTION:20-70pts.wt. carbon black and 10-100pts.wt. melamine resin are blended with 100pts.wt. urethane rubber to obtain the desired urethane rubber compsn. which gives vulcanized rubber having a hardness (JIS A) of 85-100. Examples of the urethane rubbers are pref. millable urethane elastomers obtd. by reacting the active hydrogen atoms of a polyester or a polyether with isocyanate groups in an equimolar ratio. Examples of the melamine resin are resinous materials obtd. from the condensation reaction of melamine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to urethane rubber compositions. More specifically, the present invention relates to an unvulcanized urethane rubber composition that can provide a vulcanized rubber with high hardness.

In general, vulcanized rubber has elasticity over a wide range of strain that is not found in other materials, so it is widely used for rubber rules and the like. When used as a rubber roll, especially a platen rubber roll (dot type), it is required to have high hardness (approximately 85 to 100 in J Engineering SA), wear resistance, and high rebound modulus.

Currently, styrene-butadiene rubber or nitrile rubber is used for such applications, but in order to make these vulcanized rubbers have a hardness of about 85 to 100, rubber 10
For example, about 10 to 100 parts by weight of sulfur or about 10 to 60 parts by weight of phenol resin is blended with respect to 0 parts by weight. However, although the hardness of the vulcanized rubber can be increased by such a combination, the actual situation is that the side soles are not satisfied in terms of abrasion resistance and rebound resilience. For this reason, urethane rubber has recently come to be increasingly used for such applications.

By the way, instead of using unvulcanized urethane rubber and compounding a high content of sulfur and phenolic resin for vulcanization using organic peroxide, HAF grade carbon lacquer is used for 100 parts by weight of rubber. Approximately 70~120ffi
A high hardness vulcanized rubber is formed by blending the claws with the button. However, in this way, Kae Takakura's HAF
If grade carbon black is blended, the rebound resilience of the vulcanized rubber and the rubber processability of the unvulcanized rubber composition will be impaired (see Comparative Example 8 below). Elasticity and unadded 11i
As a result of various studies on the modification method of carbon black-containing unvulcanized urethane rubber that can give a highly hard vulcanized rubber without impairing the rubber processability of the ifl rubber composition, it was found that blending a specific proportion of melamine resin is extremely effective. I found it to be effective.

Therefore, the present invention relates to a urethane rubber composition, which contains about 20 to 70 parts by weight of carbon black and about 1 to 100 parts by weight of carbon black per 100 parts by weight of urethane rubber.
Contains 100% melamine resin. If other thermosetting resins such as xylene resin or epoxy resin are used instead of melamine resin, the processability of the unvulcanized rubber composition will be improved, but vulcanization will not take place, and other rolls may Even phenolic resins that are blended into commercial rubber are not vulcanized,
Furthermore, unsaturated polyester resins do not exhibit the rebound effects of vulcanized rubber or the co-modifying effects of rubber processability of unvulcanized rubber compositions.

The urethane rubber is polyester or e.

Millable type urethane elastomers are preferably used, which are polymerized by reacting the active hydrogen of riether with isocyanate groups in equimolar proportions. Commercially available products can also be used for these, such as Sumitan 6408, a product of Sumitan 6408, Sakai Ihi Manabu's UN-168 ammunition is used.

Carbon black as a filler is HAF.

Regardless of the type, such as FKF, urethane rubber is used in a proportion of about 20 to 70 parts by weight per 100 molded parts.If carbon black is used within this range, it includes being used in combination with melamine resin. Vulcanized rubber with high hardness can be formed without impairing rubber processability. That is, if carbon black is used in a proportion higher than this, the rubber processability will be impaired, and if the proportion is lower than this, the hardness will be inferior.

As the melamine resin, a tree IIW-like substance obtained by a melamine condensation degree of 116 is used, and a commercially available product such as Matsushita Tunko product 0P9012 can be used as it is. As shown in Examples 1 to 4 and Comparative Examples 1 to 3 below, the melamine resin is used at a ratio of about 10 to 100 parts by weight, preferably about 15 to 60 parts by weight, per 100 parts by weight of urethane rubber. It will be done.

Urethane rubber, carbon black and melamine 4? J
Urethane rubber compositions containing flit as an essential component include:
Ordinary rubber compounding agents such as organic peroxide vulcanizing agents, vulcanization accelerators, anti-aging agents, softeners, and other processing aids are appropriately blended. FA manufactures unvulcanized urethane rubber compositions made of these ingredients after kneading each ingredient other than the vulcanizing agent and softening agent using an oven roll or the like. This is done by sequentially adding and kneading.

The urethane rubber composition according to the present invention has good rubber processability, and when it is vulcanized, the abrasion resistance is not substantially impaired, and the urethane rubber composition has a higher shell strength and a higher impact resilience. Therefore, it can be effectively used for com rolls, bearings, and backing backup rings 7x.

Next, the present invention will be described in detail with reference to examples.

Examples 1 to 4, Comparative Examples 1 to 3 Urethane rubber (Bayer Urethane Product Sumitan 64
0S) 100 parts (weight, same below), 65 parts of FICF carbon black, 1 part of stearic acid, anti-aging j! i
1 part of n (Shinjugaku Products Antigen White), dicumyl peroxide vulcanizing agent (NOF Bark Mill D)
6 parts, polyester thread softener (azocarbon gas product P
After kneading 10 parts of N350) and a predetermined amount of melamine resin (Matsushita Electric Works OP 9012) with each component other than the vulcanizing agent and the softening agent using a 12-inch open roller kneader, the additive and vulcanization were added. The ingredients were added in this order and kneaded.

The time required for kneading was about 40 minutes, and the temperature of the unvulcanized rubber composition at the end of kneading was 80°C.

This unvulcanized rubber composition and compression molding were vulcanized for 30 minutes at 150°C using a press. In Example 2, 1 equivalent amount of xylene resin ( Matsushita Electric Works products 0:r20) or epoxy resin (Japanese Ciba Geigy products Araldai) MY 7
20) was used. In all cases, roll-making properties were good, but vulcanization was not performed.

Comparative Example 6 In Example 2, instead of the melamine resin, the same amount of phenol resin (Sumilite Resin 126
87'') was used. This unvulcanized rubber composition was not vulcanized.

Comparative Example 7 In Comparative Example 1, the dicumyl peroxide vulcanizing agent was
0 copies were used. This unvulcanized rubber composition was not vulcanized.

Comparative Example 8 In Comparative Example 1, 100 parts of HAF carbon black was used in place of 65 parts of FKF carbon black.

Comparative Example 9 In Example 2, the same amount of unsaturated polyester resin (Japan Copica 131 product Copica 852) was used instead of the melamine resin.
4”) was used.

Table 2 below shows the measured binding +d in Comparative Examples 8 and 9 above.

Table 2 Comparative example 89 Hardness (JIS A) 94 94 Tensile strength (hfAgo) 300 221 Elongation (%)
17(+ 26(+ Repulsion Resilience (%) :((330 Abrasion (oo) 0.077 0.1.58 Cyulastometer Torque 60℃ 35.0 14.7 150℃ 18.0 1.4 01 Workability Poor Based on the results above poor, the following can be said.

(1) By blending melamine resin with carbon black-containing urethane rubber, the proportion of carbon black to be blended can be reduced, improving the impact resilience of vinyl rubber and the rubber processability of unvulcanized rubber compositions. . Regarding the mixing ratio of melamine resin, it is necessary to mix about 10 to 100 parts by weight of melamine resin to 100 parts by weight of urethane rubber, and if it is less than this, the hardness of the vulcanized rubber will be insufficient, so carbon black is further added. There is a need,
On the other hand, if more than this is added, the drop in rebound and abrasion resistance will be significant.

(2) When other thermosetting resins are blended into urethane rubber instead of melamine resin, unsaturated polyester resins are inferior to the rebound properties of vulcanized rubber and the rubber processability of unvulcanized rubber compositions; Vulcanization did not occur when compounding with 2-rubber fat, xylene resin, or epoxy resin.

Representative Patent Attorney Yoshi 1) Toshio Proceeding Amendment (Spontaneous) October 17, 1981 1. Indication of the case 1982 Patent Application No. 147427 2. Name of the invention Urethane rubber composition name (438) Japan Oil Seal Industry Co., Ltd. 4,
Agent address: 501 Ato Building, 1-2-7 Shiba Daimon, Minato-ku, Tokyo
Column 6 of the Detailed Explanation of the Invention in the Specification of No. 6, Contents of the Amendment (1) In the 2nd line directly below the 5th item, "in particular" was changed to "by virtue of"
Correct to.

Claims (1)

Claims: 1. A urethane rubber composition comprising about 20 to 70 parts by weight of carbon black and about 10 to 100 parts by weight of melamine resin per 100 parts by weight of urethane rubber. 2. The urethane rubber composition according to claim 1, which provides a vulcanized rubber having a hardness (JTech SA) of about 85 to 1()0. 3. Claim 1 used for rubber roll molding
The urethane rubber composition according to item 2.