JPS59126426A - Resin molding material for cleaning mold - Google Patents

Abstract

PURPOSE:The titled molding material capable of cleaning molds without damaging them, containing an epoxy resin, phenolic resin, amino resin, inorganic filler having specific hardness, and a fibrous filler. CONSTITUTION:An epoxy resin (e.g., bisphenol A type, etc.) is blended with a phenolic resin (e.g., novolak, resol phenolic resin, etc.), an amino resin (e.g., melamine resin, etc.), an inorganic filler (e.g., rutile-type titanium oxide, etc.) having >=4 Mohs' hardness, and a fibrous filler (e.g., pulp, glass fiber, nylon fiber, etc. having <=0.4mm. fiber length), to give the desired molding material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention belongs to the field of resin molding materials used for cleaning contaminants from injection molds and transfer molds.

[Background technology]

Conventionally, when molding material is molded in a mold, the molding material components adhere to and accumulate on the inner surface of the mold, causing mold spiders 9, deteriorating the appearance of the molded product, and impairing mold releasability. was. For this reason, the method of cleaning the mold is to heat the mold to a high temperature to carbonize or deteriorate the molding material filled in the mold, then remove it little by little with a metal rod, and then remove the mold with a solvent. The mold was immersed in the mold for a long period of time to swell and soften, and then removed little by little, but the cleaning process was difficult and took a long time, and the mold was often damaged.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks and aims to easily clean the mold without damaging the mold.

[Disclosure of the invention]

The present invention is a mold cleaning resin molding material characterized by containing an epoxy resin, a phenol resin, an amino resin, an inorganic filler having a Mohs hardness of 4 or more, and a fibrous filler. Explain. When molding material is continuously molded in a mold for a long period of time, contaminants such as the mold release agent in the molding material and volatile gas generated by heating accumulate on the inner surface of the mold, causing the mold to become cloudy and causing poor appearance of the molded product. This will cause mold release defects. Therefore, it is necessary to periodically remove mold contaminants at some point. The present invention eliminates contaminants accumulated on the inner surface of the mold by molding with the mold cleaning resin molding material of the present invention instead of stopping the molding operation at the time of removing mold contaminants. It reacts with the resin molding material for mold cleaning of the present invention, is exfoliated and extruded, and the mold can be easily cleaned without damaging the mold. Moreover, it has the advantage that there is no need to interrupt the molding operation.

Epoxy resins used in the present invention include bisphenol A type epoxy resins, novolac type epoxy resins, resol type epoxy resins, flexible epoxy resins, brominated epoxy resins, glycidylnisdale type epoxy resins, polymer type epoxy resins, etc. Epoxy resins in general such as individual resins, modified products, and mixtures can be used without any particular limitation. The phenol resin may be any phenol resin such as a novolak type phenol resin, a resol type phenol resin, etc. alone, a modified product, or a mixture thereof, and is not particularly limited. The amino resin may be an amino resin gold film such as a single amino resin, a modified product, or a mixture of amino resins such as urea resin, melamine resin, and guanamine resin, and is not particularly limited. The inorganic filler is necessary to raise the melt viscosity to 7F and extrude mold contaminants, and as an inorganic filler, Mohs hard J! ! : Rutile type titanium oxide of 4 or more, glass powder, crystalline silica, etc. are used. That is, the purpose is to polish the surface of the mold when extruding mold contaminants. The fibrous filler is used in the mold of the present invention.
70 It is necessary to improve the strength of the cleaning resin molding material and make it easier to remove the molded product from the mold.The fibrous filler includes pulp with a fiber length of 0.4# or less, fJil powder,
Any fibrous filler such as wood flour, glass fiber, Tetoron fiber, nylon fiber, acrylic fiber, etc. can be used without any particular limitation. Furthermore, if necessary, a curing agent, a curing accelerator, a mold release agent, a plasticizer, a coloring agent, etc. may be added to the mold cleaning resin molding material of the present invention. In the present invention, 5 to 15 parts of epoxy resin (hereinafter referred to as parts),
It is preferable to use 5 to 15 parts of a phenol resin, an amino resin-added to glossy part, 10 to 40 parts of an inorganic filler of 1 part to 4 parts or more, and 10 to 1 part of a fibrous filler.

The present invention will be explained below using examples.

Example 1 Melamine resin Tabe, 6 parts epoxy resin, 5 parts novolac type phenol resin, 4 parts crystalline silica, 1 part glass fiber, and 1 part zinc stearate were mixed and crushed to produce a resin molding material for mold cleaning. I got it.

Example 2 Main parts of melamine resin, 15 parts of epoxy resin, and 15 parts of novolac type phenol resin were mixed with L part of crystalline silica, glass fiber branches, and 1 part of zinc stearate, and then crushed to obtain a mold cleaning resin molding material. Ta.

Comparative Example 60 parts of melamine resin, 2 parts of silica and 2 parts of zinc stearate were mixed and ground to obtain a resin molding material for mold cleaning.

〔Effect of the invention〕

The mold cleaning resin molding materials of Examples 1 and 2 and Comparative Example above were used in a mold contaminated with epoxy resin molding material at a mold temperature of 170°C, a front cylinder temperature of 110°C, and a rear cylinder temperature of 110°C. 80°C1 injection time 15 seconds, holding time 1
As clearly shown in Table 1, the results of injection molding in 0 seconds showed that the resin molding material for mold cleaning of the present invention had good cleaning properties, confirming the superiority of the present invention.

Table 1 Pouring 1 Number of injections required to remove mold cloudiness and obtain a good appearance of the molded product.

patent applicant Matsushita Electric Works Co., Ltd. Representative Patent Attorney Toshiku Takemoto (2 others)

Claims (1)

[Claims] A mold cleaning resin molding material comprising an epoxy resin, a phenol resin, an amino resin, an inorganic filler having a Mohs hardness of 4 or more, and a fibrous filler.