JPH0516250A - Phenol resin-impregnated fiber drawing method - Google Patents

Abstract

PURPOSE:To obtain fine molded form having no void by adding and mixing specific para-toluene sulfonic acid and aluminum hydroxide to specific acid- setting type phenol resin using para-toluene sulfonic acid as a neutralizer and dipping reinforced fibers into a resin liquid, a curing temperature of which is brought to a fixed temperature or less, and curing the resin liquid. CONSTITUTION:A glass roving 1 in which glass filaments are bundled is drawn into an impregnating tank 2 filled with a liquefied resol resin composed of 100 pts.wt. acid-setting type phenol resin, 5-15 pts.wt. para-toluene sulfonic acid and 50 pts.wt. aluminum hydroxide, and impregnated with the resin. Phenol- resin blended liquid pickup is adjusted by contraction rolls 6, 6', and the glass roving is carried to a draw die 4 heated and held at a temperature of 70 deg.C or lower. A molded from 5, which is drawn from the die 4 and is not collapsed by resin cure, in which no void is generated and which has no crack, is manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin-impregnated fiber pultrusion method.

[0002]

2. Description of the Related Art Conventionally, reinforcing fibers such as roving glass fibers have been dipped in an impregnation tank filled with thermosetting phenol resin as a molding means for phenol resin products reinforced with reinforcing fibers, and excess liquid is squeezed with a squeezing roll. After removing the volatile components such as water by using a preliminary dryer, remove them and keep the temperature at 150-200.
A production method of carrying out curing and molding in a drawing die heated to ° C is adopted (for example, JP-A-2-182437).

[0003]

[Problems of the prior art] However, the curing reaction of the thermosetting phenolic resin for impregnating glass roving reinforcing fibers is a reaction between a methylol group and a methylol group.
Requires heating at ℃. The reaction cures with condensation water, but the solvent remaining in the resin liquid together with the condensation water also evaporates at high temperature, so it remains as voids in the molded product, which deteriorates the physical properties of the molded product and deteriorates the surface condition. There was a problem. Furthermore, there is a method of using acid-curable phenolic resin as a method of suppressing the rapid evaporation of solvent and condensed water by lowering the molding temperature, but in the case of phenolic resin with an acid other than para-toluenesulfonic acid as the neutralizing acid, gold is used. There was a problem of corroding the mold.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is to reduce the molding curing temperature at the time of impregnation drawing by impregnating a reinforcing fiber such as a strand or roving with an acid curing type phenol resin. The present invention has been made for the purpose of providing a pultrusion molding method for resin-impregnated fibers, in which a molded product having a beautiful surface state can be manufactured without corrosion of a mold used for molding.

[0005]

[Means for Solving the Problems] That is, the method for pultruding a fiber impregnated with a phenol resin of the present invention is carried out by adding 5 to 15 parts by weight of paratoluenesulfonic acid to 100 parts by weight of an acid-curable phenol resin having paratoluenesulfonic acid as a neutralizing agent. Parts and aluminum hydroxide are added and mixed, and the reinforcing fibers formed into strands are immersed in a resin liquid whose curing temperature is adjusted to 70 ° C or lower, and the resin-impregnated fibers are conveyed to a mold and cured. Is.

[0006]

[Function] In order to lower the curing temperature using the acid-curable phenol resin, it is possible to lower the reactivity by selecting the reactivity of the resin and the type and concentration of the curing agent. The use of paratoluene sulfonic acid as a curing agent has few impurities and low corrosiveness. Also, at a molding temperature of 70 ° C or less, the corrosiveness of the mold is not recognized in a short period of time, and acid curing This is because it is the best as a curing agent for type phenolic resin. This is because if the addition amount is 5 parts by weight or less, a low molding temperature is not secured and curing is not sufficiently performed, and if it is 15 parts by weight or more, the physical properties are deteriorated due to the influence of residual acid. Aluminum hydroxide is added to stabilize the PH of the molded product, improve the moldability, stabilize the size of the molded product, and impart flame resistance.

[0007]

Embodiments of the present invention will be described below. Figure 1
Shows a side view of an apparatus for carrying out the method of the invention. Example 1 A glass roving 1 in which glass filaments are bundled is drawn into an impregnation tank 2A filled with a liquid resole resin consisting of 100 parts by weight of an acid-curable phenol resin, 10 parts by weight of paratoluenesulfonic acid, and 50 parts by weight of aluminum hydroxide. Was impregnated. The temperature of the liquid resol resin 2 in the impregnation tank 2A was room temperature and the viscosity was 3,000 centipoise. Next, the impregnated amount of the phenol resin compounding liquid was adjusted by the squeezing rolls 6 and 6 ′, and it was conveyed to the drawing die 3 which was heated and maintained at a temperature of 70 ° C. The molded body 5 pulled out from the mold 3 loses its shape due to resin curing,
A solid product without voids or cracks could be molded.

Comparative Example 1 A thermosetting phenolic resin liquid was used as the impregnating liquid 2 and the mold temperature was 1
Molding was performed in the same manner as in Example 1 except that the temperature was set to 50 ° C.

Next, the bending strength and the specific gravity of the molded articles obtained in Examples and Comparative Examples were measured, and the results shown in Table 1 were obtained.

[0010]

[Table 1] As is clear from Table 1, it was found that molding at a low temperature (80 ° C.) increased the density of the molded body and at the same time significantly improved the strength.

When the inner surface corrosion state of the mold was observed in the above molding process, the results shown in Table 2 were obtained.

[0012]

[Table 2] * The mold test column shows the solution temperature and immersion time when the mold was immersed in a 10% aqueous solution of p-toluenesulfonic acid. ** Corrosion of mold surface --- It depends on the inner surface observation.

[0013]

As described above, according to the present invention, since the self-heating of the impregnating resin liquid at room temperature when curing is as low as 70 ° C., the mold is not corroded and the machine can be easily managed. In addition, since the amount of condensed water released is small, voids are not generated in the molded product, and as a result, it is possible to obtain a molded product having high specific gravity and high strength.

[Brief description of drawings]

FIG. 1 is a side view of essential parts of an apparatus for carrying out the method of the present invention.

[Explanation of symbols]

 1 glass roving 2 impregnation tank 3 impregnation liquid 4 mold 5 molded product 6, 6'squeezing roll

Claims (1)

Claims: 1. Curing temperature is obtained by adding 5 to 15 parts by weight of paratoluene sulfonic acid and aluminum hydroxide to 100 parts by weight of an acid-curable phenol resin having para-toluene sulfonic acid as a neutralizing agent, and curing the mixture. A method for drawing a phenol resin-impregnated fiber, which comprises immersing the reinforcing fiber formed into a strand in a resin liquid adjusted to 70 ° C. or lower, and conveying the resin-impregnated fiber to a mold to cure the fiber.