JPS5941354A - Thermosetting resin molding composition - Google Patents

Abstract

PURPOSE:To provide a composition composed of a melamine resin modified with poly-p-vinylphenol, and capable of giving a molded article having improvd heat resistance and dimensional stability. CONSTITUTION:A melamine resin modified with poly-p-vinylphenol is used as the main component of the titled resin composition. The resin can be prepared either by mixing a methylol-melamine resin with a resin obtained by the partial hydroxymethylation of a poly-p-vinylphenol, or by synthesizing methylol-melamine as the first stage reaction, and adding and condensing poly-p-vinylphenol to the methylol melamine as the second stage reaction. The molar ratio of formaldehyde to the sum of melamine and poly-p-vinylphenol is 1.3-3, and the weight ratio of the melamine resin to poly-p-vinylphenol is 10-50:90-50 in the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermosetting resin molding composition containing a melamine resin as a main component.

An object of the present invention is to provide a melamine-based thermosetting resin molding composition that can improve the durability and dimensional stability of molded articles.

Conventionally, in order to achieve such a purpose, there have been three methods: ■ a method of fusing melamine sugar with phenol or epoxy, ■ a method of compounding it using inorganic fillers such as asbestos, talc, glass fiber, mica, etc. ■ The above ■ The method of using , (2) in combination resulted in poor hitting power, but the desired effect was not obtained sufficiently.

In view of these circumstances, the inventor made extensive studies to fully achieve the above objective, and as a result, discovered that it was sufficient to modify melamine resin with polyvarabinylphenol, and completed this invention. .

Therefore, this invention ~ has melamine resin as the main component,
The gist of the present invention is a thermosetting resin molding composition characterized in that this melamine resin is modified with polyparavinylphenol. This will be explained in detail below.

The thermosetting resin molding composition according to the present invention has a melamine resin as its main component, and if necessary, it may contain ordinary additives such as inorganic fillers such as asbestos, tarta, glass fiber, and mica, an acidic oxidizing agent, and a mold release agent. Agents may be included.

The melamine m fat used in this invention is modified with polyparavinylphenol. Polyparavinylphenol is produced by the following formula, and the product named "1/Resin" manufactured by Maruheki Oil Co., Ltd. is well known.

Modification of melamine resin with polyparavinylphenol 6 is carried out, for example, as follows.

Polyparavinylphenol'K is partially methylolated to synthesize resin (2), and this resin (2) is mixed with methylolated melamine resin (2) obtained by a separate reaction.

Or Q, as a first stage reaction, methylol melamine is totally synthesized, and as a second stage reaction, polyparavinylphenol is added to this methylol melamine at any stage during the manufacturing process, and is added and condensed. In the latter case, during the second stage reaction,
Formaldehyde f: Add as necessary. The composition of the polyparavinylphenol-modified melamine resin is such that the molar ratio of omaldehyde to the total amount of melamine and polyparavinylphenol is 1.3 to 3.0, and the weight ratio of melamine resin to polyparavinylphenol is 1.3 to 3.0. It is preferable that the total amount of polyparavinylphenol is 10 to 50%.

In the thermosetting resin molding composition according to the present invention, since the melamine resin is modified with polyparavinylphenol, the heat resistance and dimensional stability of molded products obtained using the composition are sufficiently improved. Improve. It can also be given a hardness similar to that of porcelain.

Next, examples will be described together with comparative examples.

[Example 1] Resin 250I obtained by partially methylolizing polyparavinylphenol and -methylolated melamine resin 3
50g of paste resin, add an appropriate amount of phthalic anhydride as a hardening agent, zinc stearate as a mold release agent, and further add 400g of glass fiber (3mm cut product) as a filler.
was added and mixed, kneaded using a heating roll, and the resulting sheet was pulverized to obtain a powdered molding material.

[Example 2] A melamine resin sill was obtained by reacting Type 37 formalin and melamine at 98° C. for 90 minutes using a caustic soda catalyst. The F/M molar ratio at this time is 2. Next, this was cooled to 60°C and put into a secondary tank, and 30 parts by weight of polyparavinylphenol was added thereto, and asbestos and 3 mm long glass fibers were added as fillers by 20 parts by weight each. , a small amount of zinc stearate was added as a process lubricant, and heated at 60"C for 30 minutes to permeate the mixture. Next, this mixture was dried and dehydrated in a box-shaped natural circulation dryer. It was made into a compacted sheet using a roll, and then crushed to obtain a powdered molding material.

[Comparative Example J Melamine solid resin (F/M molar ratio: 2) 600g
Add appropriate amounts of phthalic anhydride curing agent and zinc stearate as a male molding agent to the mixture, add 400 g of glass fiber (cut into 3 mm) as a filler, mix, mix using a heated roll, and form a sheet-like material. It was pulverized to obtain a powdered molding material.

The performance of each of the above-mentioned molding materials is shown in Table 1, and all of the Examples had better IT than the Comparative Examples.

Table 1 *1: Based on JIS K 6911. “C/2
Maximum temperature at which no blistering or cracking occurs during H treatment.

Rice 2: 145℃, 2 minutes, 100 kg/cm2
Shrinkage rate after molding using a disc mold with a warp of 100 mm and a thickness of 5 mm under the following conditions.

One patent author: Matsushita Electric Works Co., Ltd. Agent: Patent Attorney Takehiko Matsumoto

Claims (4)

[Claims] (1) A thermosetting resin molding composition comprising a melamine resin as a main component, the melamine resin being modified with polyparavinylphenol. (2) The thermosetting resin according to claim 1, wherein the modification with polyparavinylphenol is carried out by mixing a resin obtained by partially methylolizing polyparavinylphenol with a methylolated melamine resin. Composition for resin molding. (3) Modification with polyparavinylphenol is performed by polyparavinylphenol lft polycondensation as a second-stage reaction to methylolmelamine synthesized as a first-stage reaction. A thermosetting resin molding composition. (4) The composition of the resin component is such that the molar ratio of formaldehyde to the total amount of melamine and polyparavinylphenol is 1.3 to 3.0, and the weight fJ ratio of melamine resin and polyparavinylphenol is polyparavinylphenol. 10-50 qA of paravinylphenol, the balance being melamine resin (%).Claim 1. Tanning.The thermosetting resin molding composition according to claim 3.