JPH04363354A - Melamine resin molding material - Google Patents

Abstract

PURPOSE:To obtain a melamine resin molding material, capable of providing molded products, conforming to the Food Sanitation Law and having high transparency and suitable as wiring tools, electric appliances, etc. CONSTITUTION:A melamine resin molding material is obtained by blending melamine resin and/or solid melamine resin with the solid melamine resin subjected to treatment at a high temperature of 120-170 deg.C for 0.5-5hr at (3:7) to (7:3) ratio and further blending 100 pts.wt. above-mentioned resin with 0.01-3 pts.wt. curing agent (e.g. hexamine), 0.05-5 pts.wt. mold release agent (e.g. a fatty acid or a metallic salt of the fatty acid) and, as necessary, a filler or a colorant.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melamine resin molding material used for wiring devices, electrical appliances, kitchen appliances, household goods, etc.

0002

[Prior Art] Conventionally, molded products made of urea resin and melamine resin have been highly valued as they are hard and highly resistant to staining.Urea resin molding materials can produce transparent molded products, but the Food Sanitation Law Moreover, it could not be used as tableware, and transparent molded products could not be obtained using melamine resin molding materials.

0003

[Problems to be Solved by the Invention] As described in the prior art, transparent molded products cannot be obtained using melamine resin molding materials. The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to provide a melamine resin molding material from which transparent molded products can be obtained.

0004

[Means for Solving the Problems] The present invention adds a melamine resin and/or a solid melamine resin to a solid melamine resin treated at high temperature, and further adds a hardening agent, a mold release agent, a filler, a coloring agent, etc. as necessary. The above object can be achieved because the melamine resin molding material is characterized in that the present invention is described in detail below.

The melamine resin used in the present invention contains 1.2 to 3 moles of formaldehyde per mole of melamine at a pH of 8.
~12. It is obtained by reacting at 60 to 95°C, and in the case of solid melamine resin, it is obtained by dehydration under reduced pressure. Melamine resins also include modified melamine resins such as epoxy-modified and phenol-modified. The high temperature treatment of the solid melamine resin is preferably carried out at 120 to 170°C for 0.5 to 5 hours. That is, at 120°C for less than 0.5 hours, transparency tends to decrease;
This is because moldability tends to decrease if the time is exceeded. The ratio of the high temperature treated solid melamine resin to the non-high temperature treated resin is preferably 3:7 to 7:3. That is, if the high-temperature treated resin is less than 3, transparency tends to decrease, and if it exceeds 7, moldability tends to decrease. As the curing agent, hexamine, phthalic anhydride, etc. are used, and it is preferable to add 0.01 to 3 parts per 100 parts by weight of the resin (hereinafter simply referred to as parts). As the mold release agent, fatty acids, fatty acid metal salts, wax, etc. are used, and it is preferable to add 0.05 to 5 parts to 100 parts of the resin. Fillers added as necessary include talc, clay, silica, calcium carbonate,
Inorganic powder fillers such as aluminum hydroxide, fibrous fillers such as glass fibers, asbestos fibers, pulp fibers, synthetic fibers, and ceramic fibers are used. The above-mentioned materials are blended, mixed, kneaded, pulverized, and further granulated if necessary to obtain a melamine resin molding material. The molding material is molded by compression molding, transfer molding, injection molding, or the like.

The present invention will be explained below based on examples.

[0007]

[Example] 1 mole of melamine: 1.
The melamine resin obtained by adding 6 mol of the mixture and reacting at 85° C. and pH 9 for 1 hour was dehydrated under reduced pressure at a degree of vacuum of 100 TORR to obtain a solid melamine resin. Next, the solid melamine resin was heat-treated at 150°C for 2 hours to obtain a high-temperature-treated melamine resin, including 60 parts of the high-temperature-treated melamine resin, 40 parts of a non-high-temperature-treated solid melamine resin, 0.5 part of phthalic anhydride, and calcium stearate. One part was blended, mixed, kneaded, and crushed to obtain a melamine resin molding material. Next, the molding material was molded using a transfer molding machine at a mold temperature of 145°C and a molding pressure of 1.
00Kg/cm2 A molded product was obtained by molding with a curing time of 3 minutes.

[0008]

[Comparative Example 1] A molded article was obtained in the same manner as in Example except that 100 parts of non-high temperature treated solid melamine resin was used instead of high temperature treated melamine resin.

[0009]

[Comparative Example 2] A molded article was obtained in the same manner as in Example except that a transparent urea resin molding material was transfer molded.

The performances of the Examples and Comparative Examples are shown in Table 1.

[0011]

[Effects of the Invention] The present invention is constructed as described above. It was confirmed that the melamine resin molding material having the structure described in the claims complies with the Food Sanitation Law and has good transparency, thus demonstrating the superiority of the present invention.

Claims (1)

[Claims] [Claim 1] A melamine resin and/or a solid melamine resin is added to a solid melamine resin treated at a high temperature, and a curing agent, a mold release agent, and if necessary, a filler, a coloring agent, etc. are added. Melamine resin molding material.