JPS62290732A - Production of low-hardness rubber abrasive - Google Patents

Abstract

PURPOSE:To produce the title abrasive excellent in flexibility and elasticity, by incorporating a polymeric elastomer which does not crosslink with a crosslinking agent. CONSTITUTION:Abrasive grains (e.g., diamond dust), a crosslinking agent, 100pts. wt. binder rubber which can crosslink with the crosslinking agent (e.g., butadiene rubber), 20-100pts.wt. polymeric elastomer which does not crosslink with the crosslinking agent (e.g., ethylene/alpha-olefin copolymer) and, optionally, carbon black, a white pigment (e.g., clay), a crosslinking accelerator, a crosslinking aid, a process oil, a low-MW plasticizer, an antioxidant, etc., are mixed together and molded. The obtained molding is crosslinked.

Description

Detailed Description of the Invention 8. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing a rubber Pjl material using rubber as a bond of abrasive grains.

[Prior art]

It is known that the cutting and polishing properties of an abrasive material improve as the content of abrasive grains increases. In rubber abrasives using rubber as a binder, the volume fraction of abrasive grains is generally 2.
More than 0%, often more than 80%, sometimes 80%
In such cases, the low hardness, flexibility, and elasticity that are characteristic when used as a rubber bond are lost, and there is a problem that it is difficult to conform to the shape of the material to be polished. .

[Problem that the invention seeks to solve]

In order to solve the problems of the above-mentioned prior art, it is possible to reduce the hardness and give flexibility to some extent by adding process oil, a low molecular weight liquid plasticizer (for example, dioctyl phthalate, diisobutyl phthalate), etc. to increase the amount of φ. However, if a large amount of abrasive grains absorbs process oil or low molecular weight liquid plasticizer, the improvement effect is lost, or if there is no absorption at all, the process oil or low molecular weight liquid plasticizer migrates to the surface. As a result, their effectiveness is lost over time, and the appearance of the product is impaired, so their use is limited. Conventionally, it has been difficult to use rubber abrasives with low hardness and high flexibility.

[Means for solving problems]

The present invention relates to a novel method for reducing the hardness and imparting flexibility and elasticity to a rubber abrasive material in which rubber, which is a bond of abrasive grains, is crosslinked using a crosslinking agent. More specifically, the present invention relates to a method for manufacturing a rubber abrasive material, which comprises containing an elastomer polymer that is not crosslinked with the crosslinking agent.

Examples of the combination of a crosslinking agent and a rubber serving as a bond crosslinked by the crosslinking agent in the present invention include the following.

(1) Items that can be crosslinked with a sulfur-based crosslinking agent Natural rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, ethylene-α-olefin-nonconjugated diene copolymer rubber, chloroprene rubber, halogenated ethylene-α-olefin-nonconjugated Diene copolymer rubber, etc. (2) Crosslinked with a metal oxide crosslinking agent Chloroprene rubber, halogenated ethylene-α-olefin copolymer, halogenated ethylene-α-olefin-nonconjugated diene copolymer, chlorosulfone Polyethylene, etc. (3) Items that can be crosslinked with an amine crosslinking agent Acrylic rubber, fluororubber, etc. On the other hand, the following are examples of combinations of polymeric elastomers that are not crosslinked with the crosslinking agent or have extremely low crosslinking and the crosslinking agent. Examples include things like.

(1) Ethylene that cannot be crosslinked with a sulfur-based crosslinking agent
α-olefin copolymers, halogenated ethylene-α-olefin copolymers, acrylic rubber, silicone rubber, fluororubber, etc. (2) Materials that cannot be crosslinked with metal oxide crosslinking agents or amine crosslinking agents Natural rubber, butadiene rubber, styrene rubber, etc. Butadiene rubber, nitrile rubber, ethylene-α-olefin copolymer, ethylene-α-olefin-nonconjugated diene copolymer, silicone rubber, etc. Also, soft ethylene-vinyl acetate copolymer, soft polyvinyl chloride, atactic polypropylene, etc. Depending on the combination with a crosslinking agent, it can be selectively used as a non-crosslinked polymeric elastomer, if necessary.

Other cross-linking agents include peroxide-based cross-linking agents, but since they cross-link many polymeric elastomers, when used for the purpose of the present invention, they are more effective than cross-linking with peroxides, such as natural rubber. It can be used when using an elastomer polymer that decomposes rapidly. In addition to the above, several other crosslinking agents are known and are appropriately used depending on the rubber ring used.

As the amount of the polymeric elastomer that is not crosslinked with a crosslinking agent increases, the rubber abrasive becomes less hard and more flexible. The layer used is 20 to 100 parts per 100 M parts of rubber as a bond crosslinked with a crosslinking agent, but sometimes more than 10 G\jL parts are used. 1. The type, molecular weight and amount of the elastomer to be used can be determined in consideration of the desired hardness, flexibility, moldability of the rubber abrasive, strength, abrasion resistance, etc.

The abrasive grains used in the present invention are not particularly limited, but diamond particles, alumina, carborundum, etc. are preferably used.

Bonding holiday 'IM IT-KKNO! Cross-linked by abrasive grains, cross-linking agent, and cross-linking agent! Il1mj:ll-ys14ノL'llτ
E1. jrL)%s#f-1) In addition to the pleasant and difficult-to-crosslink polymeric elastomer, carbon black, white filler (e.g. clay, talc, calcium carbonate, silica, etc.), crosslinking accelerator, crosslinking Auxiliary agents, process oils, low molecular weight plasticizers, anti-aging agents, various stabilizers, pigments, and various resins within a range that does not impair the characteristics of rubber are mixed using a banbury, kneader, roll, etc., and then pressed. , molded using an extruder, roll, oven, etc., and crosslinked to produce the desired rubber abrasive material.

Examples] Examples of the present invention are shown below, but the present invention is not limited thereto.

Examples 1 to 3, Comparative Example 1 Alumina and sulfur crosslinkable nide as abrasive grains! J route
An example using an ethylene-propylene copolymer that does not crosslink with the polymer will be shown. Table 1 shows the formulations, and Table 2 shows the evaluation results.

jI1 Table (Formulation) The hardness of the abrasive material was prepared using a kneader using the composition shown in Table 1, cross-linked for 16 minutes at 160°C using a press, and the surface of the iron plate was manually polished using kerosene as a lubricant. The polishing characteristics were evaluated based on the degree to which the polished iron powder dispersed in kerosene and turned black.

Table 2 (Evaluation results) When each abrasive was manually polished on the surface of an iron plate,
After 50 reciprocations, the kerosene turns considerably black and has excellent abrasive properties.

By increasing the amount of ethylene-propylene copolymer that cannot be crosslinked with WrLlR, the hardness can be significantly reduced without impairing the polishing properties, and flexibility can be imparted, resulting in improved shape compatibility with the object to be polished. Improved.

Examples 4 to 6, Comparative Example 2 Examples of ethylene-propylene-ethylidene norbornene copolymer (hereinafter referred to as ENB-based EPDM)-based rubber abrasives are shown below.

Table 8 (Composition) The above composition was prepared using a kneader, and 1
Crosslinking treatment was performed at 60° C. for 20 minutes to obtain a two-stroke thick abrasive material. The results are shown in Table 4. Because diamond was used as the abrasive grain, the polishing properties were 1c @, and the kerosene turned black after 80 reciprocating polishings. The examples had low hardness and good shape compatibility.

Table 4 (Evaluation Results) Examples 6 to 7, Comparative Example 3 An example of a chloroprene rubber abrasive material using full fat oxide as a crosslinking agent is shown.

Table 5 (Blend) The hardness of the abrasive can be lowered by using styrene-butadiene rubber or ethylene-propylene copolymer in combination with chloroprene rubber. Although the hardness of the comparative example increases by 7 points due to secondary heat treatment, it increases by 8 points in Example 6 and only 2 points in Example 7, which is used in combination with chloroprene rubber.Styrene-butadiene rubber and ethylene propylene rubber It can be seen that the polymer rubber is not crosslinked.

〔Effect of the invention〕

By using the present invention, a low hardness rubber abrasive material that can cut and polish metals, glass, ceramics, etc. can be obtained.

Claims (1)

[Claims] A flexible material characterized in that, when producing a rubber abrasive material by crosslinking rubber as an abrasive binder using a crosslinking agent, an elastic polymer material that cannot be crosslinked with the crosslinking agent is also used as an abrasive binder. A method for producing a low hardness rubber abrasive with excellent properties.