JPS638433A - Surface-treating method - Google Patents

Abstract

PURPOSE:To prevent mutual sticking of elastomers in stacking, by undercoating an elastomer with a thermosetting phenolic resin or a resorcinol resin and then top-coating with an emulsified wax or silicone oil. CONSTITUTION:A surface of an elastomer is coated with a solution or dispersion of a thermosetting phenolic resin or resorcinol resin as an under-coating surface- treating liquid and then with a solution, emulsion or dispersion of a wax and a silicone oil as a top-coating surface-treating liquid to form a double coating layers on the surface. The phenolic compound is e.g. phenol, cresol, etc. The baking of the phenolic resin is carried out at 120-200 deg.C for 10min.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a post-treatment surface treatment method for preventing adhesion that occurs when elastic bodies are stacked.

(Conventional technology) Conventionally, molded products made of elastic materials such as bearing seals or oil seals have caused problems when stacked or packaged because they stick to each other and cause blocking. For this reason, post-treatment to prevent adhesion is required, and countermeasures have been taken by applying a surface treatment liquid or chemically changing the surface with chemicals.

[Problem that the invention seeks to solve]

However, in the former method of applying a surface treatment liquid, the surface treatment liquid obtained by dissolving silicone oil and a surfactant in an organic solvent, or the emulsion-type silicone oil-based surface treatment liquid, is used more as an aesthetic treatment than as an anti-blocking agent. Although it is effective as an agent, it is not only unable to sufficiently suppress the adhesive force, but also has the disadvantage that the surface of the elastic body leaks due to liquid components such as silicone oil, causing poor appearance. The latter type of chemical treatment chemically treats the surface, such as by halogenating diene rubber, to lower the friction coefficient and harden only the surface to prevent blocking. In order to obtain surface roughness and surface hardening, there remain very difficult problems in adjusting the chemical blending ratio and processing time, and it is also expensive, and there are many drawbacks such as the residual halogen that can lead to rust in composite products containing metal. It had

[Means for solving problems]

The present invention eliminates these drawbacks and provides a surface treatment method that is effective as a countermeasure against slippage and blocking.

The present invention applies a surface treatment liquid for undercoat using a solution or dispersion of thermosetting phenolic resin or resorcinol resin, and then applying a surface treatment liquid for topcoat obtained by applying waxes and silicone oil as a solution, emulsion or dispersion. This is a surface treatment method characterized by coating the surface of an elastic body such as rubber to form two layers.

[Effect]

By pre-forming a cured film of thermosetting phenolic resin or resorcinol resin on the surface of an elastic body such as rubber, the stickiness peculiar to rubber is masked and bloom bleed of the lubricant and plasticizer in the rubber is suppressed.

Furthermore, by applying a solution, emulsion or dispersion of waxes, silicone oil, etc., the sliding and blocking effects of the elastic body can be sufficiently improved, and the surface treatment method does not impair the appearance of the molded product.

In addition, phenols as used in the present invention refer to phenol and phenol derivatives, such as phenol, ortho-
, meta, vala cresol, vara-t-butylphenol, vara-nonylphenol, 3.5 xylenol, α-
naphthol, β-7thol, catechol, bara-t-
These include butylcatechol, hydroquinone, etc. alone or as a mixture of several types.

Further, in the present invention, the surface treatment liquid may be applied by any method such as dipping or spraying.

The phenolic resin is baked at 120°C to 200°C for 10 minutes, preferably at 150°C for 10 minutes.

Next, examples will be shown.

〔Example〕

0 Surface treatment liquid for undercoat (A) 0 Surface treatment liquid for topcoat (B) ooy Prepare 1000 bearing seals each of 10 types with different diameters, and mix them on the surface of the elastic body in advance in the proportions shown above. The surface treatment liquid (A) for undercoat obtained by the method is applied by dipping, and the ethanol is evaporated by air drying. Next, it was dipped in surface treatment liquid CB for top coating, and then cured in a gear oven at 150°C for 10 minutes. In addition to stacking 100 of these, we also prepared 1000 bearing seals without surface treatment liquid, stacked 100 of these in the same way, and left them in an atmosphere at 40°C for 7 days to check the blocking state. Observed.

As a result of observation, no blocking was observed on the bearing seals treated with the surface treatment liquid, and the products remained in good condition.

However, the bearing seal without surface treatment liquid is 1
An average of 90 out of 00 sheets caused blocking, which was difficult to remove.

〔Effect of the invention〕

In this way, the present invention eliminates the stickiness peculiar to the elastic body and reliably prevents blocking by forming a hard and thin film such as phenolic resin on the surface of the elastic body. The top coating provides an ideal surface treatment method that further improves the sliding properties and eliminates the problems of poor appearance and rust.

It goes without saying that this surface treatment method is not limited to bearing seals and oil seals, but can be widely applied to products made of elastic materials such as rubber where blocking is a problem.

Claims (1)

[Claims] After applying a surface treatment liquid for undercoating with a solution or dispersion of thermosetting phenolic resin or resorcinol resin, a surface treatment liquid for topcoat obtained as a solution, emulsion, or dispersion of waxes and silicone oil is applied to the elasticity of rubber, etc. A surface treatment method characterized by applying it to the surface of the body to form two layers.