JPS58122926A - Production of laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet excellent in electrical insulation as well as impact resistance, by impregnating bases successively with a melamine resin, an OH-terminated water-soluble polyester resin and an unsaturated resin varnish, laminating the bases and then curing the laminate without application of pressure. CONSTITUTION:Bases such as Kraft paper or glass cloth are impregnated with about 10-20wt% methylolmelamine resin, and then the melamine-treated bases are impregnated with about 3-10wt% OH-terminated water-soluble polyester resin. Then, the treated bases are impregnated with an unsaturated resin varnish comprising an unsaturated bond-containing unsaturated resin such as an unsaturated polyester resin or a vinyl ester resin, a crosslinking agent and an initiator. Then, the resulting resin-impregnated bases are laminated so as to form a belt. The laminate is cured without application of pressure, for example, by heating it in a heating furnace to form the purpose laminated sheet.

Description

[Detailed description of the invention] This invention relates to a method for manufacturing a laminate.

The following method has been developed as a continuous forming method for laminates used for electrically insulating substrates, etc. That is, an unsaturated resin having an unsaturated bond such as an unsaturated polyester resin, diallyl phthalate 14 resin, or vinyl ester resin is diluted with a vinyl monomer (crosslinking agent), and then a polymerization initiator is added to form an unsaturated resin liquid (phenol). ) and impregnate a base material such as a strip of paper or glass cloth with it to continuously create a resin-impregnated base material. Next, a plurality of sheets of this resin-impregnated base material are stacked while being transferred, and if necessary, strip-shaped copper foil, release film, etc. are stacked while being transferred to continuously form a strip-shaped laminate. Then, the laminate is heated under 11.5 pressure (pressureless molding) while being transferred using a heating furnace to continuously produce a laminate.

This method has high production efficiency because the laminates are continuously produced by heating and curing them under no pressure, without applying heat and pressure to the laminates one by one. In addition, when producing unsaturated resin varnish, the unsaturated resin is diluted with a crosslinking agent rather than with a solvent to create phenol, so there is no need to use a solvent, which is excellent in terms of resource saving. .

In this method, by impregnating the base material with an amino resin prior to impregnation with the unsaturated resin pheno,
It is known to improve the properties of a laminate. This K certainly improves general properties such as electrical insulation and flame retardancy. However, on the other hand, mechanical strength such as impact resistance and bending strength deteriorates.

Therefore, an object of the present invention is to improve mechanical strength such as impact resistance and bending strength while maintaining good general properties such as electrical insulation and flame retardancy.

This purpose is achieved by pre-treating the base material by impregnating it with a melamine resin and then impregnating it with a polyester resin having an 10H group at the end of its molecular chain.

In this way, the method for manufacturing a laminate according to the present invention involves obtaining a strip-shaped laminate using a resin-impregnated base material obtained by impregnating the base material with an unsaturated resin phenol, and curing the laminate under no pressure while transferring it. A method for obtaining a laminate by using a base material which is impregnated with a melamine resin and then impregnated with a water-soluble polyester resin having an 10H group at the end of the molecular chain. shall be. This will be explained in detail below.

As the base material, known materials such as paper and glass cloth are used.

This is first preprocessed as follows. That is, methylolmelamine resin is impregnated in an amount of 10 to 20% by weight (hereinafter abbreviated as "Chi"), preferably 12 to 16% by weight. Thereafter, this melamine-treated base material is impregnated with 3 to 10 units of a water-soluble polyester resin having 10H groups at the end of its molecular chain. If the amount of water-soluble polyester resin impregnated is less than 3, an improvement in mechanical strength is expected, but if it exceeds 10, electrical insulation properties tend to deteriorate. In addition, it is preferable to add 10 to 20 PHR of a curing agent to the water-soluble polyester resin.

The thus pretreated base material is impregnated with an unsaturated resin varnish to obtain a resin-impregnated base material. Unsaturated resin phenol is produced by diluting unsaturated resins with unsaturated bonds, such as unsaturated polyester resins, diallyl phthalate resins, and vinyl ester resins, with a crosslinking agent such as styrene, etc., and adding a polymerization initiator. Become.

The method for impregnating melamine resin or water-soluble polyester resin and the method for impregnating unsaturated resin pheno are generally known methods such as dipping method and coating method.

A strip-shaped laminate is produced using the strip-shaped resin-impregnated base material thus obtained. This is no different from before.

That is, a strip-shaped laminate is continuously obtained by overlapping one or more resin-impregnated base materials with a metal foil such as copper foil or a release film, if necessary. All of this is done while the material is being transferred. Then, the obtained strip-shaped laminate is heated in a heating furnace or the like, and the laminate is cured under no pressure while being transferred, thereby continuously producing a laminate.

As stated above, the method for manufacturing the laminate according to this invention is as follows:
The base material that makes the resin-impregnated base material is first impregnated with melamine resin, and then impregnated with polyester resin having 10H groups at the end of the molecular chain, so it has electrical insulation and flame retardant properties. It is possible to efficiently and inexpensively produce a laminate that has good general properties such as the following, as well as good mechanical strength such as impact resistance and bending strength.

Next, examples will be described together with comparative examples.

[Example 1] Kraft paper with a thickness of 10 mils (0,254 mm) was used as the base material, and melamine resin (manufactured by Nippon Carbide Co., Ltd., S
-305) was impregnated into the base material at 12%*.

Furthermore, the base material was treated with a water-soluble polyester resin (manufactured by Nagase Chemical Industries, Ltd., CE Re5in8) to which a curing agent was added, so that the amount of impregnation was 3.
A pretreated base material was obtained. Next, this was added to an unsaturated polyester resin (manufactured by Inu Nippon Ink Co., Ltd., FG) diluted with styrene.
-104) to obtain a resin-impregnated base material, a predetermined number of base materials were stacked on top of each other, and a laminate was obtained by heating and curing under no pressure.

This product had good film properties and mechanical strength.

[Examples 2 to 5] The amount of melamine resin impregnated and the amount of water-soluble polyester resin impregnated were as shown in Table 1. Otherwise, a laminate was obtained in the same manner as in the example.

[Comparative example]

The amount of melamine resin impregnated was 14%, and the impregnation of water-soluble polyester resin was omitted. Otherwise, a laminate was obtained in the same manner as in the example. Although this product satisfied the general properties, it was unsatisfactory in terms of mechanical strength.

The above table shows the pretreatment conditions of the base material, general properties, and measurement results of mechanical strength in Examples and Comparative Examples as shown in Table 1.

All of the Examples were superior to the Comparative Examples.

(Hereafter, extra white)

Claims (2)

[Claims] (1) A method of obtaining a strip-shaped laminate using a resin-impregnated base material obtained by impregnating the base material with an unsaturated resin varnish, and curing the laminate under no pressure while transferring the base material, the method comprising: A method for manufacturing a laminate, characterized in that the material used is a material impregnated with melamine resin and then impregnated with water-bathable polyester resin having an 10H group at the end of the molecular chain. (2) The base material is made of methylol melamine resin from 10 to 200%.
20% by weight, and 3-10% by weight of a water-bathable polyester resin having an 10H group at the end of the molecular chain.