JPS6411237B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a coating composition, and more particularly to a coating composition suitable for applying to the surface of an elastic body to impart lubricity to the surface.

Technical background of the invention and its problems There are cases where it is necessary to impart lubricity to the surface of an elastic body. For example, this is the case with automobile glass runs. In other words, automobiles are equipped with elevating window glass in the door section, and in order to prevent vibration by holding the window glass that moves up and down, and to prevent rainwater, dust, etc. from entering the passenger compartment, the window frame is installed. A glass run is installed in some parts. Since such a glass run and the window glass are in sliding contact, it is preferable that the contact surface of the glass run with the window glass has lubricity.

By the way, conventional glass runs for automobiles have been widely used with flocked nylon pile etc. on the contact surface with the window glass, but the manufacturing process of such flocked glass runs is Moreover, sliding on the window glass can cause wear, and in winter, water droplets adhering to the flocked area can freeze, making it difficult for the window glass to move or impairing the sealing function. There was a problem that dust and other substances could enter the room.

For this reason, attempts have been made to solve the above problems by forming a coating capable of imparting lubricity to the contact surface of the elastic body that is the glass run base material. For example, in Japanese Patent Publication No. 57-14986,
A glass run for an automobile is disclosed in which a coating composition made of a polyurethane rubber base with addition of a fluororesin and a silicone oil is applied onto a polyvinyl chloride resin base material to form a film. However, the specific gravity of fluororesin is 2.14 to 2.20, which is extremely large compared to silicone oil.
The fluororesin will settle and separate in the coating composition. Therefore, when applying this coating composition onto a glass run base material, there was a problem in that the coating composition had to be constantly circulated or stirred to prevent the fluororesin from settling. .

Purpose of the Invention The present invention is an attempt to solve the problems associated with such conventional techniques, and is capable of imparting lubricity to the surface of an elastic body by applying it to the surface of the elastic body, as well as heat resistance and heat resistance. A coating composition that can be applied to the surface of an elastic body to impart lubricity to the surface, which can provide a film with excellent weather resistance and abrasion resistance, and does not require stirring or circulating the coating composition during application. is intended to provide.

Summary of the Invention The coating composition according to the present invention, which is applied to the surface of an elastic body to impart lubricity to the surface, is characterized by the addition of polystyrene resin beads and silicone oil to a polyurethane rubber base.

In this paint composition, the polystyrene resin beads retain the silicone oil well, so the silicone oil is retained in the paint film for a long time, dramatically improving durability, and the polystyrene resin beads retain the silicone oil for a long time. It has an excellent effect of not causing sedimentation and separation in the coating composition.

DETAILED DESCRIPTION OF THE INVENTION The coating composition according to the present invention, which is applied to the surface of an elastic body to impart lubricity to the surface, is composed of a polyurethane rubber base, polystyrene resin beads, and silicone oil. Let's explain the ingredients.

Polyurethane rubber broadly refers to rubber elastic bodies produced by the reaction of isocyanates with two or more isocyanate groups and compounds with two or more active hydrogens, and is widely used in rubber materials known for use in paints. Can be used. Specifically, a thermoplastic isocyanate-crosslinked chain polyurethane rubber obtained by reacting a diisocyanate having two isocyanate groups and a glycol as a compound having two active hydrogen atoms in equimolar amounts is used. In addition, long chain glycols such as polyester glycols, polyalkylene ether glycols, polyalkylene oxyether glycols, long chain hydrocarbon glycols, etc. obtained by the reaction of dibasic organic acids and glycols, and diisocyanates can be obtained. Polyurethane rubber can also be used.

Further, by adjusting the ratio of the above glycol and diisocyanate, a long chain diisocyanate whose terminal group is an isocyanate group or a long chain glycol whose terminal group is a hydroxyl group is prepared as a prepolymer, and the terminal group is an isocyanate group. In the case of long-chain diisocyanates, water, diamine,
A crosslinking reaction is caused by using an active hydrogen atom-containing compound such as an amino alcohol, glycol, or polyol as a crosslinking agent, and in the case of a long chain glycol whose terminal group is a hydroxy group, a crosslinking reaction is caused by using an isocyanate as a crosslinking agent. It is also possible to use polyurethane rubber with the resulting network structure.

In practice, one-component polyurethane paint or two-component polyurethane paint
Commercially available polyurethane paints can be used as liquid polyurethane paints, and among these, one-component polyurethane paints are preferred. That is, 1
Liquid-based polyurethane paints do not require the mixing of a curing agent during application and do not cause pot-life problems, and the desired coating film can be obtained by simply drying the solvent, making it possible to use two-component polyurethane paints. This is because long-time drying or high-temperature treatment is unnecessary. One-component polyurethane paints also have the advantage of stable quality because there is less variation in reaction unlike two-component polyurethane paints.

Polystyrene resin beads are thought to have the function of retaining silicone oil in the paint composition through actions such as adsorption, and for this reason, the silicone oil is retained in the paint film for a long period of time, and this paint The lubricity of the surface of the elastomer to which the composition is applied is ensured. Therefore, by applying a coating composition containing polystyrene resin beads and silicone oil to the surface of an elastic body, it is possible to improve the durability of the elastic body, such as surface smoothness after being held at high temperatures for a long time, and irradiation with ultraviolet rays for a long time. After polishing, the surface smoothness is maintained well, and the wear resistance under high temperature atmosphere is significantly improved.

The particle size of polystyrene resin beads is 30μ or less,
The thickness is preferably 15μ or less, more preferably 10μ or less. If the particle size of the polystyrene resin beads exceeds 30 μm, it is not preferable because the retention of silicone oil decreases.

Since the polystyrene resin beads have a specific gravity lower than that of the fluororesin, they do not settle and separate in the coating composition, and therefore there is no need to stir or circulate the coating composition during application.

Silicone oils include dimethyl silicone oil, methyl chloride silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, fluorosilicone oil, Silicone oil made of linear polydimethylsiloxane and having a viscosity of 60,000 to 150,000 may be used. Among these, linear polydimethylsiloxane is particularly preferred.

The coating composition according to the present invention usually contains an organic solvent for dissolving or dispersing the above components, and examples of the organic solvent include methyl ethyl ketone, acetone, toluene, xylene, benzene,
Tetrahydrofuran, dimethylformamide, methyl acetate, isopropyl acetate, trichloroethane, methylpyrrolidone, and the like can be used.

Furthermore, catalysts such as organotin compounds are added to the coating composition to promote the urethanization reaction, and ultraviolet absorbers and antioxidants are added to improve the light resistance of the resulting elastomer with surface smoothness. You can also. Furthermore, pigments and the like can be added to the coating composition as needed.

In some cases, polymeric compounds such as methyl methacrylate may be added to the coating composition in order to improve the curing of the resulting coating film or to improve the adhesion between the elastomer and the coating film. You can also do it.

In the coating composition according to the present invention, it is desirable that the polyurethane rubber and the polystyrene resin beads exist in a weight ratio of 3:7 to 8:2, preferably 4:6 to 6:4. Moreover, it is desirable that the polystyrene resin beads and silicone oil exist in a weight ratio of 2:8 to 8:2, preferably 4:6 to 6:4.

The coating composition according to the present invention is applied onto the surface of the elastic body, and any application method may be used at that time, such as dip coating, spray coating, brush coating, roll coating, etc. will be adopted. The thickness of the coating film is preferably 10 to 80 μm, preferably 30 to 60 μm.

Examples of the elastic body to which the coating composition of the present invention is applied include soft polyvinyl chloride resins, polyurethane resins, and various synthetic rubbers. Vinyl chloride resin is preferred.

Effects of the Invention The coating composition according to the present invention, which is applied to the surface of an elastic body to impart lubricity to the surface, has polystyrene resin beads and silicone oil added to a polyurethane rubber base, and the polystyrene resin beads add silicone oil. Since the silicone oil is retained for a long period of time, the silicone oil is retained in the coating film for a long period of time, and the durability of the elastic body having a slippery surface is dramatically improved. Further, when this coating composition is applied onto the surface of an elastic body, no separation and sedimentation of polystyrene resin beads is observed.

The present invention will be explained in detail by examples below.
The invention is not limited to the examples.

Example 1 A coating composition for forming an automobile glass run having the following composition was prepared.

One-component urethane rubber base (P27MPNAT, manufactured by Nippon Polyurethane Industry Co., Ltd.) 25 parts by weight Silicone oil 31.5 parts by weight Polystyrene resin beads (Fine Pearl
3000F average particle size 6 μ) 30 parts by weight Methyl methacrylate 11 parts by weight Organic solvent 450 parts by weight Pigment 4 parts by weight Antioxidant Appropriate amount Ultraviolet absorber Appropriate amount A glass run for automobiles was manufactured by coating the resin and drying it.

The following various tests were conducted on this automotive glass run.

(a) Wear test at room temperature (b) Wear test after keeping the glass run under high temperature conditions for a long time (thermal deterioration test) (c) Wear test after irradiating the glass run with ultraviolet rays (weather resistance test) (d) Abrasion test in a high temperature atmosphere (60℃) (e) Abrasion test after leaving the glass run in water for a long time (water resistance test) The above abrasion test was performed using a flat abrasion tester.
This was done by repeatedly rubbing the glass run sample surface under a constant load and examining the degree of wear.

This glass run was tested in a wear test at room temperature.
It shows good lubricity even after being rubbed over 15,000 times, it shows good lubricity even after being rubbed over 10,000 times in a heat aging test, and it shows good lubricity even after being rubbed over 10,000 times in a weathering test. In an abrasion test under a high-temperature atmosphere, it showed good lubricity even after being rubbed over 4,000 times, and in a water resistance test, it showed good activity even after being rubbed over 10,000 times.

The thus obtained automobile glass run exhibited extremely good abrasion resistance in all tests.

Also, when the coating composition was applied onto a glass run base material, no separation and sedimentation of polystyrene resin beads was observed.

Comparative Example 1 A glass run for an automobile was produced in the same manner as in Example 1, except that fluororesin beads were used instead of polystyrene resin beads.

The obtained glass run was considerably inferior in terms of durability compared to the glass run obtained in Example 1.

Claims (1)

[Claims] 1. A coating composition for applying to the surface of an elastic body to impart lubricity to the surface, which is characterized in that polystyrene resin beads and silicone oil are added to a polyurethane rubber base.