JPS5820978B2 - Phenolic resin molding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phenolic resin molding material.

In general, phenolic resins have excellent moldability, mechanical performance, physical performance, and especially heat resistance, considering their price.
Widely used as a molding material.

. As a result of repeated research to further improve these performances, the inventors found that reducing the amount of unreacted phenol in a phenolic resin improves the cylinder stability during molding of a molding material using it. Improved heat resistance and dimensional stability of phenolic resin molded products.

I found something that could be improved.

By the way, the following method has been used to reduce the amount of unreacted phenol in the resin.

That is, when the resin is a resol-type phenolic resin (hereinafter abbreviated as "resol"), the molar ratio F/P of formaldehyde (F) to phenol (P) is adjusted during resin production.

(2) A method is used in which the reaction time is increased and the reaction is carried out under slightly alkaline conditions.

However, when the resin is produced as described in (2), although the amount of unreacted phenol in the resin is reduced, formaldehyde remains, resulting in poor impact resistance of molded products made from the molding material. A problem arose.

Furthermore, when the resin is produced as in (2), the resulting resin becomes polymerized, which causes the problem that the fluidity of the material deteriorates when it is made into a molding material.

Furthermore, when the resin was manufactured as in (2), the curing speed of the resulting resin increased, resulting in a problem that the molding width became smaller.

On the other hand, when the resin is a novolac-type phenolic resin (hereinafter abbreviated as 1 novolac), the amount of catalyst is adjusted during resin production, or dephenolization is performed after production. The amount of reacted phenol was reduced.

However, since unreacted phenol acts as a plasticizer for novolak, when its content is reduced, the fluidity of a molding material using it during molding is significantly reduced, resulting in poor moldability.

The above-mentioned problems arise due to a decrease in the amount of unreacted phenol when the amount becomes less than about 8.0% by weight.

The inventors have conducted repeated research to solve the above-mentioned problems that have arisen by reducing the amount of unreacted phenol in the phenolic resin, and have found that 3-methyl-
When 1,3,5-pentane I-'1ol is included,
This invention was completed after discovering that such problems were solved and that the effects of reducing the amount of unreacted phenol (cylinder stability during molding, heat resistance, and dimensional stability of molded products) were not impaired.

In other words, the present invention has a phenolic resin containing 8% by weight or less of unreacted phenol as a main component, and 3-methyl-
The gist thereof is a phenolic resin molding material containing 1,3,5-pentanetriol.

Next, this invention will be explained in detail.

This invention provides phenolic resin molding materials containing 3-
It contains methyl-1,3,5-pentanetriol (trade name: Petriol, manufactured by Kuraray Co., Ltd.).

In other words, 3 in the above phenolic resin molding material.
-By containing methyl-1,3゜5-pentanetriol, all the problems that arise from using resols and novolacs with low unreacted phenol content can be solved, and moreover, it is possible to reduce the amount of unreacted phenol. There is no loss of effectiveness.

To explain in more detail, in the case of (2) above, there was a problem that reducing the amount of unreacted phenol in the resol deteriorated the impact resistance of the molded product.
In such cases, the use of 3-methyl-1,3,5-pentanetriol prevents the impact resistance of the molded article from deteriorating.

In addition, in the case of (2) above, reducing the amount of unreacted phenol in the resol caused the resulting resin to polymerize, which worsened the fluidity of the molding material. 3-methyl-1,
When 3,5-pentane l-IJol is used, deterioration of the fluidity of the molding material is prevented due to its plasticizing action.

In addition, in the case of (1) above, reducing the amount of unreacted phenol in the resol increased the curing speed of the resulting resin, which caused the problem that the molding width became smaller. By using 1,3,5-pentanetriol, the curing speed becomes appropriate,
This makes it possible to widen the molding width.

In addition, reducing the amount of unreacted phenol in novolac has caused a problem in that the fluidity of the molding material during molding is significantly reduced; in such cases, 3-methyl-1,3, By using 5-pentanetriol, it acts as a plasticizer and prevents a decrease in flowability.

In these cases, the content of 3-methyl-1,3°5-pentanetriol is 3-methyl-1,3,5-
Pentanetriol is 0.5-5.0% by weight of the molding material
(hereinafter abbreviated as "%").

In other words, if f3. is less than 0.5%, the effect is small, and conversely, f3.
This is because if it exceeds 0%, there is a tendency for the electrical insulation properties of the molded product to decrease and the hot rigidity during molding to decrease.

In addition, 3-MeF 1°3.5
- When pentanetriol is contained, there is a tendency for the curing speed of the molding material to slow down during molding.

In such cases, the curing speed can be increased by containing 3-methyl-1,3°5-pentanetriol and resol.

In this case, it is preferable to adjust the amount of resol used depending on the content of 3-methyl-1,3,5-pentanetriol.

Usually, the combined ratio of both is (3-methyl-1
,3゜5-pentanetriol)/(resol)=11
Selected as 5-5/1.

Note that 3-methyl-1,3,5-pentanetriol and 3-methyl-1,3,5-pentanetriol + resol are added to the molding material when mixing and kneading the phenol resin and filler, etc. What is necessary is just to make it contain.

In addition, the raw materials other than those mentioned above are those commonly used, and the molding material is manufactured by a known method.

As described above, this invention contains 3-methyl-1°3.5-pentanetriol in a phenolic resin molding material whose main component is a phenolic resin containing 8% or less of unreacted phenol. Therefore, the moldability of the phenolic resin molding material can be improved without impairing the impact resistance of the molded product, the fluidity of the molding material, proper curability, etc.

Moreover, the heat resistance and dimensional stability of molded articles obtained using the same can be improved.

This invention is particularly effective when applied to heat-resistant phenolic resin molding materials containing inorganic fillers with poor moldability.

The molding material of the present invention is extremely useful as a molding material that can produce molded products with excellent long-term mechanical strength retention under high temperatures.

Next, examples will be described together with comparative examples.

Example 1 Phenol (P) and formaldehyde (F) were blended so that the molar ratio F/P = 1.5, and this was hydroxylated so that the molar ratio of calcium to phenol was 0.005. Calcium was added and the mixture was reacted under reflux for 120 minutes to obtain a resin (resol) with a low content of unreacted phenol.

Next, this resin and other raw materials were blended as follows.

Resin - 40 parts by weight (hereinafter abbreviated as "1 part") Asbestos = 59 parts Magnesium stearate: 1. When kneading the above mixture in a kneader, 3-methyl-1,3,5-pentanetriol was It was added and kneaded so that its content was 2% of the total.

Next, this was dried at 90° C. for 30 minutes and ground to obtain a phenolic resin molding material.

Example 2 Each raw material was blended as follows.

In the above formulation, 3-methyl-1,3,5-pentane)
IJ-all was added so that its content was 2% of the total.

Next, this was kneaded and pulverized for 10 minutes with heated rolls at 100°C to obtain a molding material.0 Example 3 Each raw material was blended as follows.

A mixture of 3-methyl-1,3,5-pentanetriol and the resol obtained in the same manner as in Example 1 (mixing ratio 1:1) was added to the above formulation in such a manner that the total content thereof was 1:1. It was added so that the amount was 4%.

From this point onwards, a molding material was obtained in the same manner as in Example 2.

Example 4 The amount of the mixture of 3-methyl-1,3,5-pentanetriol and resol added was reduced so that the mixture was 1% of the total.

A molding material was obtained in the same manner as in Example 3 except for this.

Example 5 The amount of the mixture of 3-methyl-1,3,5-pentanetriol and resol added was increased so that the mixture amounted to 5% of the total.

A molding material was obtained in the same manner as in Example 3 except for this.

Example 6 Instead of 3-methyl-1,3,5-pentanetriol, 3-methyl-1,3,5-pentanetriol and resol obtained in the same manner as in Example 1 were mixed in a ratio of 1:5. A mixture was used, and the amount of the mixture added was adjusted so that the amount of the mixture was 4% of the total.

A molding material was obtained in the same manner as in Example 2 except for this.

Example 7 3-Methyl-1, 3,5-
A mixture of pentanetriol and resol obtained in the same manner as in Example 1 at a ratio of 5:1 was used.

A molding material was obtained in the same manner as in Example 3 except for the above.

Comparative Example 1 A molding material was obtained in the same manner as in Example 1 except that 3-methyl-1,3,5-pentanetriol was not used.

Comparative Example 2 A molding material was obtained in the same manner as in Example 2 except that 3-methyl-1,3,5-pentanetriol was not used.

While measuring the disk elongation and curing time of the phenolic resin molding materials obtained in the above examples and comparative examples,
The heat-resistant temperature of molded products obtained using the material and 20
The half-life time of 0'C bending strength was measured.

The results are shown in the table below. As is clear from the table, it can be seen that the molding materials of the examples are superior to those of the comparative examples and can produce molded products with excellent performance.

The contents of each test are as follows.

0 disc extension According to JIS.

By means of a curelastometer that detects the transmitted torque value of the 0 curing time material.

Measurement temperature is 160°C8○ heat resistant temperature JIS upper limit temperature for good surface condition based on appearance after heating.

0200°C bending strength half-life time After processing at 200°C, the time it takes for the strength to reach 50% of the initial bending strength in a JIS bending test.

Claims (1)

[Claims] 1. A phenolic resin molding material whose main component is a phenolic resin containing 8% by weight or less of unreacted phenol, and which contains 3-methyl-1,3°5-pentanetriol.