JPH04261459A - Melamine resin molding material - Google Patents

Abstract

PURPOSE:To sufficiently improve the strength of a melamine resin molding by compounding glass fibers therein. CONSTITUTION:When compounded with glass fibers, at least polyethylene glycol diglycidyl ether-modified melamine resin is employed as the melamine resin component, which can enhance the adhesivity between the melamine resin and the glass fibers by virture of its favorable compatibility therewith and effectively exhibit the reinforcing effect of the compounded glass fibers.

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 containing glass fiber.

0002

BACKGROUND OF THE INVENTION Melamine resins have traditionally been used for many purposes such as tableware, and for this reason various attempts have been made to improve properties such as appearance and boiling crack resistance. On the other hand, since melamine resin inherently has excellent arc resistance, tracking resistance, flame resistance, etc., if its strength can be increased, it will be useful for electrical-related parts. Although there have not been many reports of attempts to increase the strength of melamine resin, it is conceivable that, for example, it may be blended with glass fiber and reinforced with glass fiber.

0003

[Problem to be solved by the invention] However, melamine resin is not compatible with glass fiber, so melamine resin cannot be adhered to glass fiber, and even if glass fiber is blended, the strength of the molded product cannot be sufficiently improved. The problem was that I couldn't do it. The present invention has been made in view of the above points, and an object of the present invention is to provide a melamine resin molding material that can sufficiently improve the strength of a molded product by incorporating glass fiber.

0004

[Means for Solving the Problems] The melamine resin molding material according to the present invention is characterized in that it contains at least a polyethylene glycol diglycidyl ether modified melamine resin as a melamine resin component, and is blended with glass fiber. be. The present invention will be explained in detail below. As the melamine resin component, at least polyethylene glycol diglycidyl ether modified melamine resin is used. That is, in addition to using a general melamine solid resin and a polyethylene glycol diglycidyl ether modified melamine resin together as a melamine resin component, a polyethylene glycol diglycidyl ether modified melamine resin can also be used alone as a melamine resin component.

The above-mentioned polyethylene glycol diglycidyl ether-modified melamine resin can be produced by reacting melamine, polyethylene glycol diglycidyl ether, and formaldehyde, and drying the resultant mixture by heating, for example, as disclosed in Japanese Patent Application No. 1983.
It can be prepared as a solid resin as described in No. 3-101647. That is, it can be prepared by first reacting melamine with polyethylene glycol diglycidyl ether as a primary reaction, and then reacting this reactant with formaldehyde as a secondary reaction. The first reaction is thought to occur through ring-opening and dehydration addition of the epoxy group of polyethylene glycol diglycidyl ether to the amino group of melamine. Further, the secondary reaction is thought to occur due to the addition of formaldehyde to the unreacted amino groups of melamine. Here, it is desirable to set conditions so that the primary reaction is carried out at a temperature of about 80 to 100°C for about 10 to 150 minutes, and the secondary reaction is carried out at a temperature of about 70 to 90°C for about 5 to 120 minutes. It is desirable to set conditions so that In addition, the blending amount of each component in the above reaction is as follows: M is the number of moles of melamine, PEGE is the number of moles of polyethylene glycol diglycidyl ether, and F is the number of moles of formaldehyde. The ratio is PEGE/M=0. 01-1. 0 The molar ratio of formaldehyde to the difference in the number of moles between melamine and polyethylene glycol diglycidyl ether is F
/|M-PEGE|=0. 5-3. It is desirable to set the range so that it is 0. Generally, the number of moles M of the melamine resin is set larger than the number of moles PEGE of polyethylene glycol diglycidyl ether. What is obtained by reacting in this way is a syrup-like liquid melamine resin containing water, and by heating and drying this liquid melamine resin, the molecular weight (number average molecular weight Mn) is increased from 20,000 to 300.
00 component is about 45-65% by weight, 700-2000
It is possible to obtain a solid melamine resin containing about 15 to 25% by weight of the 0 component and about 20 to 35% by weight of the 700 or less component.

[0006] Glass fibers (glass cut fibers) are blended into the above melamine resin component, and fillers such as powder pulp and a mold release agent are also blended as needed, and this is kneaded using a roll or the like. By this,
A melamine resin molding material can be obtained.

[0007]

EXAMPLES The present invention will now be illustrated by examples. Example 1 28.8 parts by weight of melamine, 10.0 parts of polyethylene glycol diglycidyl ether with a molecular weight of 526
A polyethylene glycol diglycidyl ether-modified melamine resin was obtained by reacting with a mixture of 28 parts by weight of 40% formalin and 25.8 parts by weight of water. This polyethylene glycol diglycidyl ether-modified melamine resin is blended with melamine solid resin, glass fibers cut into short fibers, powder pulp, phthalic acid, and wax (zinc stearate) in the formulation shown in Table 1, and then kneaded with rolls to produce melamine. A resin molding material was obtained.

Examples 2 and 3 A melamine resin molding material was obtained in the same manner as in Example 1, except that the composition of the polyethylene glycol diglycidyl ether modified melamine resin and the melamine solid resin was set as shown in Table 1. Comparative Example 1 A melamine resin molding material was obtained according to the formulation shown in Table 1 without using polyethylene glycol diglycidyl ether modified melamine resin.

As described above, the melamine resin molding materials obtained in Examples 1 to 3 and Comparative Example 1 were compression molded to produce molded products. When we measured the bending strength of this molded product, we found that
The results shown in Table 1 were obtained.

0010

[Table 1]

As shown in Table 1, the polyethylene glycol diglycidyl ether-modified melamine resin has good compatibility with glass fibers, so even with the same amount of glass fibers, the resins of each example are more flexible than the comparative examples. It is confirmed that the strength can be increased.

0012

[Effects of the Invention] As described above, since the present invention contains polyethylene glycol diglycidyl ether modified melamine resin as the melamine resin component, this polyethylene glycol diglycidyl ether modified melamine resin has good compatibility with glass fibers. It is possible to improve the adhesion between the glass fiber and the melamine resin, to effectively exhibit the reinforcing effect of the glass fiber, and to sufficiently improve the strength of the molded product using the glass fiber.

Claims (1)

[Claims] 1. A melamine resin molding material comprising at least a polyethylene glycol diglycidyl ether-modified melamine resin as a melamine resin component and blended with glass fiber.