JPH03153741A - Primer for vulcanized rubber molding - Google Patents

Abstract

PURPOSE:To prevent surface coat from discoloring when a primer for a vulcanized rubber molding is used by using a halogen cation compound as an effective component. CONSTITUTION:A primer is obtained by dissolving a halogen cation compound which is a compound which forms a halogen cation in a solution (e.g. trichloroisocyanuric acid) in a solvent (e.g. ethyl acetate) in an amount to give a concentration of effective halogen of the compound of 1-50wt.%. After the surface of a vulcanized rubber molding is treated with the primer, it is coated with a coating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment agent that is applied to the surface of vulcanized rubber in advance when painting a vulcanized rubber molded article with various known paints.

Many attempts have been made to coat vulcanized rubber molded products with various paints, including polyurethane paints, in order to improve their appearance or to impart durability and weather resistance, and some of these have not been put into practical use. It's here.

However, if the anti-aging agent or vulcanization accelerator used in producing the vulcanized rubber is non-staining, there is no problem, but if any of them are staining, the anti-aging agent Alternatively, there has been a problem that the vulcanization accelerator migrates to the painted surface and contaminates the painted surface significantly. In particular, tire chip sheets (chip sheets made by hardening crushed tire chips with polyurethane resin, etc.), which were developed to utilize tire waste containing a large amount of polluting anti-aging agents, are incorporated into tires. staining antiaging agents, such as N-phenyl-N'-(1,3-dimethylbutyl)-p
- Aromatic secondary amines such as phenylene diamine and diallyl-p-phenylene diamine, reaction products of diphenylamine and a7tone, dihydroquinolines, etc. migrate to the painted surface over time, making the painted surface brown or black. The scope of its use was extremely limited due to the contamination caused by Therefore, there has been a growing demand for a primer or treatment agent that stops the migration of anti-aging agents or vulcanization accelerators contained in vulcanized rubber, but at present there are no primers or treatment agents suitable for this purpose. The reality is that no drug has yet been developed. If such a primer or treatment agent were developed, it would maintain the characteristics of vulcanized rubber, such as flexibility, elasticity, heat resistance, and cold resistance, and
Since it can be finished in any color tone that harmonizes with the environment, it does not spoil the aesthetic appearance, and it is also inexpensive.
It is estimated that the scope of use will greatly expand to include residences, parks, golf courses, public facilities, etc. Based on these voices, we conducted extensive research, and as a result, we arrived at the present invention.

That is, the present invention relates to a treatment agent containing a halogen cationic compound that is applied to the vulcanized rubber surface in advance to prevent discoloration of the painted surface when painting the vulcanized rubber molded article with various known paints. The halogen cationic compound mentioned in the present invention is a compound that generates a halogen cation alone or in a suitable solvent. Examples of halogen cationic compounds include chlorine, bromine, iodine,
Halogens such as iodine chloride, hypohalous acids such as hypochlorous acid, hypohalous salts such as sodium hypochlorite, potassium hypochlorite, calcium hypochlorite (bleaching powder), hypochlorous acid Hypohalous acid esters such as t-butyl, N-haloamines such as monochloroamine, N-monochloromethylamine, N-monochloroaniline, N
- N-heramides such as chloroacetamide, N-chlorourea, N-chlorosuccinimide, N-bromosuccinimide, N-chlorophthalimide, trichloroisocyanuric acid, sodium dichloroisocyanurate, potassium dichloroisocyanurate, or N- When preparing a surface treatment agent by dissolving these halogen cationic compounds, such as heloimides, in water or an organic solvent, the effective halogen concentration is 1% by weight or more5.
It needs to be 0% by weight or less, preferably 3% by weight or more and 30% by weight or less. The surface treatment method for vulcanized rubber moldings is usually to apply a treatment agent containing the above-mentioned halogen cationic compound with a brush, spray, etc., or to immerse it in the treatment agent, dry it in the air, and let it stand. Be taken. If necessary, active hydrogen compounds such as water, alcohols, carboxylic acids, and amines may be added to the treatment liquid.

The vulcanized rubber molded product in the present invention is a rubber obtained by adding various rubber additives to a known natural rubber or synthetic rubber, crosslinking and molding the product, and examples thereof include natural rubber (NR), polybutadiene rubber, etc. (BR), styrene-butadiene copolymer rubber (SBR), polyisoprene rubber (IR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene-propylene copolymer rubber (EPR), ethylene-
Propylene-diene monomer terpolymer rubber (EPDM)
), butyl rubber (IIR), etc., alone or in a crosslinked mixture thereof. The above-mentioned halogen cationic compound adds electrons to the non-conjugated double bonds existing near the surface of the vulcanized rubber, and as a result, the surface of the vulcanized rubber is halogenated, which prevents the migration of anti-aging agents, etc. It is to prevent it. It is also thought that one of the factors is that the contaminants that cause discoloration of the painted surface and the halogen cationic compound undergo a chemical reaction, and the contaminants change into compounds that are difficult to transfer. If necessary, in order to clean the painted surface of the vulcanized rubber, it may be wiped with toluene, methyl ethyl ketone, etc., or puffed with a wire brush, sandpaper, etc.

The paints mentioned in the present invention are urethane resin-based, acrylic resin-based, alkyd resin-based, graft-modified rubber-based, ethylene-vinyl acetate copolymer-based, polyester resin-based, and cellulose resin, regardless of whether they are solvent-based or water-based. The following two types of paints were used in the present invention.

(A) Polyurethane resin paint (2-component curing type) IK coat E U-49 White 100 Curing agent E-7
10 10 [manufactured by Kakue Gyo Co., Ltd.] (B) Acrylic resin emulsion paint (one-liquid type) IK Coat AC-100 White [manufactured by Kakue Gyo Co., Ltd.] Next, examples will be described.

Example 1 N-phenyl-N'-(dimethylbutyl)-p-phenylenediamine and diallyl-p as staining anti-aging agents
- Pulverize tire waste containing a large amount of fluorinated diamine into chips, and add Takenate F-139 (moisture curing type 1
A sheet molded using 20 parts by weight of liquid type polyurethane resin was sliced into 5 mm thick pieces to obtain chip sheets, which were used as vulcanized rubber sheets.

10 parts by weight of trichloroisocyanuric acid to 10 parts by weight of ethyl acetate
(effective halogen concentration: 8.3%) was applied to the above chip sheet with a brush. After curing at room temperature for about 60 minutes, a two-component curing type polyurethane resin paint IK Coat EU-49 White (A) was spray applied, and the film was left to dry at room temperature for 24 hours.

Although the painted sample was exposed outdoors for three months, almost no discoloration of the painted part was observed.

Example 2 Commercially available NR containing 1,3-diphenylguanidine as a staining vulcanization accelerator and poly(2,2,4-)dimethyl-1,2-dihydroquinoline as a staining anti-aging agent. The painted surface of the black rubber sheet was cleaned with toluene before use. N-bromosuccinimide 13
Part by weight was dissolved in 100 parts by weight of acetone (effective halogen concentration 5.2%) and applied to the above vulcanized rubber sheet with a brush.

After curing for about 60 minutes at room temperature, apply the one-component acrylic resin emulsion paint IK Coat AC-100 White (
B) was applied with a brush and dried at room temperature for 24 hours.

Although the painted sample was exposed outdoors for three months, almost no discoloration of the painted part was observed.

Comparative example 1 Real j! A two-component curing type polyurethane resin paint IK coat EU-49 White (A) was spray applied to the chip sheet described in Ifs1. It was dried at room temperature for 24 hours.

As a result of exposing the painted sample outdoors at r:ff for 10 days, the painted area significantly changed color to blackish gray.

Comparative Example 2 After cleaning the painted surface of the vulcanized rubber sheet described in Example 2 with toluene, a one-component acrylic resin emulsion paint was applied with a brush and dried at room temperature for 24 hours.

As a result of exposing the painted sample outdoors for 10 days, the painted area significantly changed color to brown.

Claims (1)

[Claims] A treatment agent containing a halogen cationic compound that is applied to the vulcanized rubber surface in advance to prevent discoloration of the painted surface when painting the vulcanized rubber molded product with various known paints.