JPH0657815B2 - Resin powder composition for three-layer coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a resin composition capable of closely adhering a thermoplastic nylon resin onto a metal plate via an epoxy resin layer and forming a fine layer of fluororesin powder such as polytetrafluoroethylene on the surface at once. Regarding

(Prior Art) Nylon has excellent properties such as surface lubricity, and is used as a coating material for metal surfaces because of its excellent properties.

However, since the nylon resin has low adhesiveness to metal, it requires a primer treatment for its coating, which has a drawback that the coating cost becomes high.

Further, the nylon resin coating has a drawback that it is easily scratched.

(Purpose of the present invention) The present invention provides a powder resin composition which does not require a primer treatment in electrostatic coating or the like and can form a heat resistant slide layer or a rough rough surface on the surface of a coating film.

(Problem to be solved) It is not possible to uniformly form a fluororesin fine powder layer on the surface of a coating film formed by heating and melting with a mixed powder obtained by simply mixing the fluororesin fine powder with a nylon resin powder. It is necessary to be dispersed in the nylon resin particles in advance.

The same applies to the epoxy resin and the curing agent for the adhesive layer.

In order to obtain a powder in which these constituent materials of the composition are contained in nylon resin particles at a uniform density, it is necessary to rely on the dissolution method, but it is necessary to prevent the curing reaction from occurring during the dissolution. .

The present inventor uses morpholine as a solvent capable of dissolving nylon resin below the reaction temperature of the curing agent to be used, and dissolves it at a melting temperature of 140 ° C. or below, and the fluororesin such as polytetrafluoroethylene does not dissolve in morpholine. Taking advantage of this, the same amount of fluororesin powder as nylon resin (5μ-20
It was succeeded in obtaining particles having a uniform density of 10 to 80 μm by mixing (μ commercial product).

As the fluorine resin powder, FEP, PTFE or the like is selected depending on the melting temperature or the desired properties of the surface layer.

(Constitution of Invention) The nylon resin particles of the present invention have a particle size of 10 to 80 μm,
Epoxy resin of 1 to 20% by weight with respect to the nylon resin, curing agent of 0.1 to 5% by weight with respect to the epoxy resin, and particle size of 5 to 10 to 100% by weight of nylon resin
It contains 20 μ of polytetrafluoroethylene powder.

(Example 1) Morpholine 100 and 1 were added to a stirring and dissolving tank having a volume of 150.
2 Nylon resin 5kg, Epoxy resin 500g, Hardener (Oilized Shell Epoxy, reaction temperature 150 ℃, 6 hours)
Fluorinated ethylene-propylene copolymer (FEP) (melting temperature 2
50 ℃) 3kg, nitrogen gas sealed 140 ℃, 5kg
/ Cm ² and a stirring speed of 300 rpm for about 1 hour and 30 minutes for dissolution.

Approximately 100 if heating is stopped and gradually cooled while maintaining stirring.
Particles precipitated at ° C.

When the liquid temperature dropped to about 50 ° C., the precipitated particles were filtered off with a filter press, and the produced particles were vacuum dried.

The average particle size was 40μ.

This powder is electrostatically coated on a polished iron plate and heated to 200 in a heating furnace.
When heated to ℃, as shown in Fig. 1, the epoxy resin film (2) adheres to the iron plate (1) as the first layer, and the nylon resin layer (3) is coated on the resin film as the second layer. A fused layer of FEP was formed as a third layer on the surface of the layer.

(Example 2) Polytetrafluoroethylene (PTFE) as fluororesin powder
Example 1 except that the melting temperature (300 ° C.) was 3.2 kg.
It was manufactured in the same manner as.

The surface layer formed by heating was a smooth fine uneven surface of the PTFE particles. (FIG. 2) This coating film had a hardness lower than that of the surface layer obtained by mixing ceramic particles, but showed a non-adhesive property peculiar to PTFE even on a rough surface.

(Effect) Since the powder of the present invention is not simply a mixture of fluororesin powders, when electrostatically coating an object to be coated, the adhered particles do not drop due to the difference in chargeability and are made uniform like a single resin. Is applied.

Further, the three-layered layered film is naturally formed by the difference in melting temperature and the curing reaction during heating and melting, and therefore the film thickness of each layer can be changed according to the application by changing the composition ratio.

[Brief description of drawings]

1 and 2 are schematic cross-sectional views of the coating film of the product of the embodiment.

Claims (1)

[Claims] 1. Nylon resin powder particles having a particle size of 10 to 80 .mu.
Three layers containing 20μ of fluorine resin fine particles, 1 to 20% by weight of the nylon resin, and 0.1 to 5% by weight of the epoxy resin and a curing agent having a reaction temperature of 150 ° C. or higher. Resin powder composition for coating.