JP6870367B2 - Rubber compositions, compounds, vulcanized products and rubber rolls - Google Patents

Description

The present invention relates to a rubber composition, a compound, a vulcanized product having a higher hardness, and a rubber roll made of the same, which are used for a compound having excellent processability.

Rubber rolls are used in various processes of production lines such as steel making, film, and paper making.
The rubber used for the rubber roll includes natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), butyl rubber (IIR), styrene butadiene rubber (SBR), chloroprene rubber (CR), and nitrile rubber (NBR). , Ethylene propylene rubber (EPDM) and other synthetic rubbers are selected according to the required physical properties.

When making a rubber roll, it is necessary to make a compound and process it, so that good workability is required. Generally, the compound has a low viscosity and has an appropriate adhesiveness, so that good processability can be obtained. In order to reduce the compound viscosity, it is common to select rubber with low Mooney viscosity and add oil such as softener and plasticizer. However, in order to obtain a roll with high hardness, it is common to increase the amount of inorganic filler such as carbon, add a resin harder than rubber such as high styrene, and reduce the amount of oil added such as softener and plasticizer. Yes, the addition of inorganic fillers increases the viscosity of the compound. Further, although the resin can maintain its hardness at a low temperature, it has a problem that it softens at a high temperature. Furthermore, the viscosity of the compound increases due to the weight loss of oils such as softeners and plasticizers. Therefore, workability and hardness generally conflict with each other.

On the other hand, studies have been made to improve workability and hardness (for example, Patent Documents 1 to 3). In Patent Document 1, 70-90 parts by weight of carbon black with an average particle size of 40 μm or less is blended with 100 parts by weight of NR, IR, IIR, and SBR to improve hardness, and further, a novolak-type modified phenol that is thermoplastic. Workability is imparted by using 5 to 20 parts by weight of resin, but the wear resistance is inferior due to the large number of carbon black blended parts, and it cannot be applied to rolls other than black. In Patent Document 2, 20-200 parts by weight of an inert silica-based white filler is used for IIR or EPDM to obtain a roll having excellent workability and high hardness. Carbon black was still needed because it had no reinforcing effect. Further, in Patent Document 3, a roll having high hardness is produced by using non-carbon by using a thermosetting diallyl phthalate prepolymer, but the hardness is about 70-80, which is not sufficient. Patent Document 4 states that the vulcanization rate is increased by adding active zeolite to the elastomer and resole-type resin, but there is no description regarding workability and hardness, and zeolite, which is an inorganic substance, is added as described above. By doing so, it is expected that the processability of the compound will decrease.

Chlorosulfonated polyethylene (CSM) obtained by chlorinating and chlorosulfonated polyethylene and alkylated chlorosulfonated polyethylene (ACSM) having an alkyl chain have ozone resistance, weather resistance, heat resistance, oil resistance, and chemical resistance. Since it has excellent properties and abrasion resistance, it is very useful as a rubber for rubber rolls. However, since the adhesiveness of the unvulcanized compound is inferior, it is necessary to add tack in addition to lowering the viscosity of the compound in order to obtain good processability. Therefore, when trying to obtain a roll having high hardness using CSM, ensuring its workability has been an issue.

Japanese Unexamined Patent Publication No. 05-98081 Japanese Unexamined Patent Publication No. 06-80828 Japanese Unexamined Patent Publication No. 11-241719 Japanese Unexamined Patent Publication No. 2012-82422

The present invention has been made in view of this problem, and an object of the present invention is to provide a rubber composition, a compound and a vulcanized product thereof, which can obtain a CSM rubber roll having high hardness and excellent wear resistance. It is a thing.

Against this background, as a result of diligent studies to solve the above problems, the present inventor has improved workability during compound processing by using CSM, NBR and BR as rubber components, and further obtained rubber. It has been found that the hardness and wear resistance of the product can be improved. That is, the present invention is a rubber composition containing 50 to 98 parts by weight of CSM, 1 to 25 parts by weight of NBR, and 1 to 25 parts by weight of BR, a compound containing the rubber composition and additives and a vulcanized product thereof, and a rubber roll.

Hereinafter, the present invention will be described in detail.

The rubber composition of the present invention contains at least CSM, NBR and BR as rubber components, and among the rubber components, CSM is 50 to 98 parts by weight, NBR is 1 to 25 parts by weight, and BR is 1 to 25 parts by weight ( The total rubber component is 100 parts by weight). Additives can be added to this rubber composition to make a compound, and the compound can be vulcanized and used as a vulcanized product. If the amount of NBR and BR of the rubber composition is small, the workability in the case of conbound is inferior, and if the amount of NBR and BR is large, the wear resistance in the case of vulcanized product is lowered. The following is preferable, and 5 parts by weight or more and 20 parts by weight or less are more preferable.

The CSM of the present invention is chlorosulfonated polyethylene, and various products are commercially available. The type of CSM is not particularly limited, but an alkylated CSM (ACSM) having an alkyl chain is preferable because it has more wear resistance.

The NBR of the present invention comprises a copolymer of butadiene and acrylonitrile, and various products are commercially available.

The BR of the present invention is a polymer of butadiene, and is a typical general-purpose rubber along with styrene-butadiene rubber (SBR) and natural rubber (NR), and various products are commercially available.

The compound of the present invention contains the above rubber composition and additives and has a Mooney viscosity of less than 100. If the Mooney viscosity of the compound is 100 or more, the handling is inferior and the workability is lowered.

The method for mixing the rubber composition and the compound of the present invention is not particularly limited, and is generally carried out by a method of kneading rubber such as an open roll, a Banbury mixer, a kneader, etc., for example, mixing at the same time as other additives. You just have to knead.

Examples of the additive added to the rubber composition of the present invention include a filler, a processing aid, an acid receiver, a vulcanization accelerator, an antiaging agent, a plasticizer, and the like, and if necessary, a pigment or a tackifier resin. Etc. may be used.

The filler of the rubber composition of the present invention is not particularly limited, but when producing a non-black rubber roll, an inorganic filler such as calcium carbonate or clay can be used by using silica having appropriate activity. Higher hardness can be obtained. The amount used is not particularly limited, but usually about 10 parts by weight to 70 parts by weight is used with respect to 100 parts by weight of rubber.

The processing aid is not particularly limited, and various substances can be used. For example, various waxes and fatty acids can be mentioned. Usually, 10 parts by weight or less is used with respect to 100 parts by weight of rubber, and a plurality of parts are often used in combination.

The acid receiving agent is not limited, and various substances can be used. For example, magnesium oxide, lead oxide and the like can be mentioned.

The vulcanization accelerator is not particularly limited, and various substances can be used. For example, thiourea compounds and peroxides can be mentioned.

The anti-aging agent is not particularly limited, and various substances can be used. For example, phenolic compounds and the like can be mentioned.

Various plasticizers can be used. For example, paraffin and oil can be mentioned.

Examples of the pigment include titanium oxide, and examples of the tackifier resin include a thermoplastic resin.

A vulcanized product is obtained by molding the obtained compound and subjecting it to heat and pressure treatment. The obtained vulcanized product preferably has a hardness (JIS-K6253) of 80 (JIS-A) or more. The compound can be molded into a desired shape by a method such as mold, extrusion, injection, etc., and then vulcanized by heat or high frequency. These conditions are not particularly limited, but for example, the compound of the present invention can be made into a rubber roll by winding it around an iron core and then vulcanizing it at 150 to 200 ° C.

The compound using the rubber composition of the present invention has excellent workability, and the vulcanized product and the rubber roll made of the vulcanized product have high hardness and excellent wear resistance.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

<Compound workability>
The workability in the open roll was evaluated. Good ones that do not take time to work due to excessive adhesion or insufficient adhesion.

<Measurement of compound viscosity>
After kneading according to the formulation, the Mooney viscosity (ML (1 + 4) 100 ° C.) of the compound was measured according to JIS K6300.

<Creation of vulcanized product>
After kneading according to the formulation, press vulcanization was performed at 150 ° C. for 50 minutes.
<Hardness of vulcanized product>
The hardness of the obtained vulcanization sheet was measured according to JIS K6253.

<Abrasion resistance>
It was measured according to the DIN wear test (JIS K6264).

Example 1
80 parts by weight of TOSO-CSM TS-430 (manufactured by Tosoh Corporation, Mooney viscosity 46ML (1 + 4) 100 ° C) as CSM, 10 weight of JSR N230S (manufactured by JSR Corporation, Mooney viscosity 56ML (1 + 4) 100 ° C) as NBR 10 parts by weight of JSR BR01 (manufactured by JSR Corporation, Mooney viscosity 45ML (1 + 4) 100 ° C.) was kneaded with an open roll to prepare a rubber composition. Next, the compound was kneaded according to the formulation shown in Table 1 to prepare a compound, and the viscosity of the compound was measured. Furthermore, the hardness and wear resistance of the vulcanized product were measured.

結果を表２に示す。コンパウンド粘度は低く加工性に優れ作業性は良好で、硬さは８０以上、摩耗減量も少なく、耐摩耗性は良好であった。

The results are shown in Table 2. The compound viscosity was low, the workability was excellent, the workability was good, the hardness was 80 or more, the wear loss was small, and the wear resistance was good.

実施例２
ＣＳＭをアルキル化ＣＳＭ ｅｘｔｏｓ ＥＴ−８０１０（東ソー（株）製、ムーニー粘度４１ＭＬ（１＋４）１００℃）に変更した以外は実施例１に従ってコンパウンド粘度、硬さ、耐摩耗性を評価した。結果を表２に示す。コンパウンド粘度は低く加工性に優れ作業性は良好で、硬さも８０以上であり、摩耗減量も少なく、耐摩耗性は良好であった。

Example 2
The compound viscosity, hardness, and wear resistance were evaluated according to Example 1 except that the CSM was changed to an alkylated CSM exos ET-8010 (manufactured by Tosoh Corporation, Mooney viscosity 41 ML (1 + 4) 100 ° C.). The results are shown in Table 2. The compound viscosity was low, the workability was excellent, the workability was good, the hardness was 80 or more, the wear loss was small, and the wear resistance was good.

Example 3
The compound viscosity, hardness, and wear resistance were evaluated according to Example 1 except that the ACSM used was changed to 70 parts by weight, 15 parts by weight of NBR, and 15 parts by weight of BR. The results are shown in Table 2. The compound viscosity was low, the workability was excellent, the workability was good, the hardness was 80 or more, the wear loss was small, and the wear resistance was good.

Comparative Example 1
The compound viscosity, hardness, and abrasion resistance were evaluated according to Example 1 except that 100 parts by weight of ACSM was used and NBR and BR were not used. The results are shown in Table 2. The compound viscosity was high, the workability was inferior, the workability was inferior, the wear loss was increased, and the wear resistance was inferior.

Comparative Example 2
The compound viscosity, hardness, and abrasion resistance were evaluated according to Example 1 except that NBR was not used and the amount was 90 parts by weight and 10 parts by weight of BR. The results are shown in Table 2. The compound viscosity was high, the workability was inferior, and the workability was inferior.

Comparative Example 3
The compound viscosity, hardness, and wear resistance were evaluated according to Example 1 except that BR was not used and the amount was 90 parts by weight of ACSM and 10 parts by weight of NBR. The results are shown in Table 2. The compound viscosity was high, the workability was inferior, the workability was inferior, the wear loss was increased, and the wear resistance was inferior.

Comparative Example 4
The compound viscosity, hardness, and wear resistance were evaluated according to Example 1 except that the ACSM used was changed to 40 parts by weight, 30 parts by weight of NBR, and 30 parts by weight of BR. The results are shown in Table 2. Abrasion weight loss increased and wear resistance was inferior.

Claims (7)

A composition containing at least chlorosulfonated polyethylene (hereinafter referred to as CSM), nitrile rubber (NBR) and butadiene rubber (BR) as a rubber component, and among the rubber components, CSM is 50 to 98 parts by weight and NBR. Is 1 to 25 parts by weight, and BR is 1 to 25 parts by weight (the total of rubber components is 100 parts by weight). The rubber composition according to claim 1, wherein the NBR is 5 to 20 parts by weight and the BR is 5 to 20 parts by weight. The rubber composition according to claim 1 or 2, wherein the CSM is an alkylated chlorosulfonated polyethylene. A compound comprising the rubber composition and additives according to any one of claims 1 to 3, wherein the Mooney viscosity is less than 100. The vulcanized product of the compound according to claim 4. The vulcanized product according to claim 5, wherein the hardness (JIS-K6253) is 80 (JIS-A) or more. A rubber roll made of the vulcanized product according to claim 5 or 6.