JPH0796553A - Pultrusion method of fiber-reinforced condensation polymerized resin and mold for that - Google Patents

Abstract

PURPOSE:To mold continuously and efficiently molded product free from a defect such as a void by preventing a venting hole from being clogged with resin, by releasing gas, which is formed during curing molding material while cooling the venting hole by flowing a coolant within the mold, outside of a mold. CONSTITUTION:A molding groove 6 extending in a pulling-out direction from an inlet 8 of a mold 1 to an outlet, a venting hole 7 communicating with its molding groove 6 from the outside and a coolant passage 10 to cool the vent hole 7 are provided. A molding material comprised of reinforced fiber material which is impregnated with resin is led to the inlet 8 of the mold which is caused to pass through a molding groove 6 and allowed to cure. Then the mold is constituted so that the molding material is pulled out through an outlet 9 of the mold, the coolant is circulated through the coolant passage 10, condensed gas to be formed during curing a molding material while cooling the vent hole 7 is released outside the mold through the vent hole 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pultrusion molding method for a fiber reinforced plastic molded article having a matrix of a resin which forms a polymer by condensation polymerization, such as a phenol resin, and a mold for the same. .

[0002]

2. Description of the Related Art In recent years, as structural materials for housing and construction,
Fiber-reinforced plastic molded products are often used. An unsaturated polyester resin is known as a representative example of the thermosetting matrix resin in such a fiber-reinforced plastic, but this resin has a problem of flame retardancy. On the other hand, it is widely known that a flame-retardant fiber-reinforced plastic molded article can be obtained by using a phenol resin as a matrix resin, and in recent years, fiber-reinforced plastics using such a phenol resin have been developed. Attention has been paid. Above all, pultrusion moldings of phenolic resins, which have almost no restrictions on the dimensions of molded products and can realize high mechanical strength, are promising for various applications. Therefore, there still remain some problems in the practical application of the pultrusion molding of the condensation-polymerized resin fiber-reinforced plastic for forming the matrix resin.

Unlike the radical polymerization of unsaturated polyester resins, the curing of condensation-polymerized resins such as phenolic resins is by condensation polymerization. Therefore, in molding such a condensation-polymerized resin, an important problem is how to continuously remove the condensation gas generated during the curing reaction to the outside of the system. When pultrusion molding is performed without removing the condensation gas generated during the curing reaction to the outside of the system, the condensation polymerization slows down, and the gas pressure generated increases the pultrusion resistance, and molding can be continued. Disappear. In extreme cases, the condensation gas is blown out from the inlet of the mold, resulting in unmolding.

Therefore, when molding the condensation polymerization resin,
In order to proceed the curing reaction, it is necessary to let the condensation gas out of the system. Therefore, for example, in the case of heat compression molding, the mold can be opened slightly during molding to allow the generated gas to escape to the outside of the system, and then the mold can be tightened again to complete the molding. However, in pultrusion molding in which the mold cannot be opened and closed during molding, degassing cannot be performed by such a method.

Therefore, the inventors of the present invention have conducted diligent research to solve the above-mentioned problems in the production of fiber-reinforced plastic molded products by pultrusion of a condensation-polymerized resin such as a phenol resin. Using a mold with communicating gas vent holes, while the molding material passes through the molding groove and cures, the condensation gas escapes from the molding groove through the gas vent holes to the outside of the mold, and the gas vent holes are condensed. By cooling to below the curing reaction temperature of the polymerized resin, while preventing the curing of the condensation polymerized resin in the gas vent holes in advance, it is found that the condensation polymerized resin can be continuously drawn and molded, It was the invention.

[0006]

Therefore, according to the present invention, while continuously removing the condensation gas generated by the curing reaction from the mold, the fiber-reinforced condensation polymerization resin is continuously drawn and molded. It is an object to provide a method and a mold therefor.

[0007]

The pultrusion molding method according to the present invention uses a mold having a molding groove in the drawing direction and provided with a gas vent hole communicating with the molding groove from the outside. Introduce a molding material consisting of a reinforced fiber material impregnated with resin, pass through the molding groove, harden, and pull out from the die outlet, while circulating a refrigerant in the die to cool the gas vent hole. However, it is characterized in that the condensation gas generated during the curing of the molding material is allowed to escape from the mold through the gas vent hole.

Further, in the mold according to the present invention, a molding groove extending from the entrance of the mold in the drawing direction to reach the exit, a gas vent hole communicating with the molding groove from the outside, and cooling the gas vent hole. With a refrigerant passage for, leading the molding material consisting of a reinforced fiber material impregnated with resin at the inlet, passed through the molding groove, cured, and withdrawn from the outlet,
A cooling medium is circulated in the passage to cool the gas vent hole, and at the same time, the condensation gas generated during curing of the molding material is allowed to escape from the gas vent hole to the outside of the mold.

In the present invention, the condensation polymerization resin means a thermosetting resin which forms a matrix of fiber reinforced plastics by condensation polymerization. As such a resin,
For example, a phenol resin, an amino resin, a melamine resin and the like can be mentioned, but in the present invention, a phenol resin is particularly preferably used.

Generally, in the pultrusion molding, a liquid material prepared by mixing the above-mentioned condensation-polymerized resin and, if necessary, a curing agent, a filler, a coloring agent, etc. is impregnated into a reinforced fiber material such as glass fiber roving or mat. The molding material thus prepared is introduced into a mold, heat-cured, and pulled out to obtain a molded product.

Here, as the reinforcing fiber material, in addition to the glass fiber exemplified above, carbon fiber, aramid fiber,
In addition, ceramic fibers, rovings and mats composed of combinations thereof are preferably used. Also, in order to reduce the resistance at the time of pultrusion molding and to perform molding smoothly,
An internal release agent may be added to the molding material. As a resin
When using a phenolic resin, the internal release agent
For example, stearic acid metal salt, phosphoric acid ester type, etc. can be used.

As the filler in the molding material, hydrated alumina, calcium carbonate, kaolin, clay, dolomite, talc, mica, wollastonite, glass spheres, hollow glass spheres, various whiskers, etc. can be used, and further colored. As the agent, for example, a pigment can be used.

The present invention will be described in detail below with reference to the drawings. FIG. 1 shows a perspective view of a preferred example of a mold used in the present invention. The mold 1 is composed of a pair of split molds of an upper mold 2 and a lower mold 3, and one or both of the mating surfaces 4 and 5 of the mold is along the drawing direction of the molding material indicated by an arrow A, A forming groove 6 extending from the inlet to the outlet is provided. The cross-sectional shape dimension of the molding groove 6 is determined according to the target molded product. In the mold shown in FIG. 1, a plurality of grooves are formed at equal intervals perpendicular to the molding groove 6 on the mating surface 5 of the lower mold 3 from the molding groove of the mold to the side surface of the mold, that is, outside the mold. A gas vent hole 7 is formed so as to communicate with each other.

FIG. 2 shows a perspective view of another preferred example of the mold used in the present invention. The mold 1 is also composed of a pair of split molds of an upper mold 2 and a lower mold 3, and a molding groove 6 is provided along the drawing direction of the molding material indicated by an arrow A, but in this embodiment, The gas vent hole 7 is provided so as to penetrate the side wall of the lower mold forming the molding groove 6 and communicate with the outer side surface of the lower mold. FIG. 3 shows a mold 1 including the upper mold 2 and the lower mold 3 shown in FIG. 1, and the molding groove 6 is formed by aligning the upper mold and the lower mold on the mating surfaces in this way. Is formed, and the molding material is guided to the inlet 8 of the mold.

That is, according to the present invention, the molding material is introduced into the mold through the inlet 8 of such a mold, and is heated and cured while the molding material passes through the molding groove in the mold. Is taken out from the mold outlet 9 and cut into a required length as required to obtain a molded product as a product. Although not shown, the heating means of the mold may be either steam heating or electric heating, and if necessary, a preliminary heating part such as high frequency heating may be attached to the mold. The heating temperature of the mold and the size of the mold are appropriately determined according to the molding material used and the target molded product.

In the present invention, in order to cool the gas vent hole to a temperature preferably lower than the temperature at which the condensation polymerization resin is cured, the gas vent hole is provided in the mold as shown in FIGS. 1 to 3. Proximity to 7, a passage 10 for a coolant such as water is provided in at least one of the upper mold and the lower mold. As long as the above-described object can be achieved, such a refrigerant passage is not structurally and in any way restricted by the position, number, etc. provided in the mold. For example, as shown in FIG.
A plurality of screw holes 11 are bored in the Y-shaped pipe 13 having a partition plate 12 therein as shown in FIG. 4, and a Y-shaped pipe located at one end of the mold as shown in FIG. Tube 1
The inlet pipe 15 of No. 4 serves as the inlet of the refrigerant, the outlet pipe 17 of the Y-shaped pipe 16 located at the other end of the mold serves as the outlet of the refrigerant, and the other Y-shaped pipes 18 and 19 use these as the adjacent outlet pipes. The inlet pipe and the inlet pipe are connected by a connecting pipe 20 such as a rubber pipe, and thus the refrigerant is circulated in the mold in the vicinity of the gas vent hole and allowed to pass therethrough, and the condensation polymerization around the gas vent hole is performed. Cool to a temperature below the curing reaction temperature of the resin. According to the Y-tube 13 described above, the refrigerant supplied from the inlet of the Y-tube to the inside of the Y-tube is guided to the tip of the Y-tube by the partition plate 12, and then returns to the outlet tube. , The inside of the mold can be effectively cooled.

In the present invention, the size and shape of the mold are appropriately determined according to the molding material used and the target molded product, but normally the molding groove of the mold must have a length of 30 cm or more. , The maximum length is not limited, but preferably 60 ~
It is in the range of 120 cm. When the length of the molding groove of the mold is shorter than 30 cm, it is difficult to secure the amount of heat necessary for curing the molding material, depending on the drawing speed of the molding material, and the molding material may not cure properly. It may occur. However, if the length of the mold groove exceeds 120 cm,
This is practically disadvantageous because the pulling resistance of the molding material increases. Further, the size and shape of the gas vent hole are also appropriately determined according to the molding material used, the heating temperature of the mold, etc. For example, the groove width is about 20 mm and the depth is about 2 to 3 mm.
In addition to the dimensions and shape of the gas vent holes, the position, number, size, etc. of the grooves are not particularly limited to these.

The heating temperature of the mold depends on the type of molding material used and the size and shape of the molded product, but in the case of molding of a phenol resin, it is preferably 150 ° C. or higher for practical use, and particularly 160 to Temperatures in the range of 180 ° C are preferred.
After the obtained molded product is taken out from the mold, it may be post-heated if necessary.

After passing a continuous molding material through the molding groove of the mold as described above and raising the temperature of the mold to a predetermined temperature, Y
Cooling water is passed through the character tube to cool the gas vent hole. In this way, after confirming that the heating and cooling of the mold have been stabilized, by pulling out the molding material from the exit of the mold at a constant speed, the fiber-reinforced phenolic resin molded product is continuously produced. Obtainable.

The drawing speed depends on the molding material used, the heating temperature of the mold, the size and shape of the molded product, etc.
It is in the range of 200 to 600 mm / min. Withdrawal speed is 20
When it is 0 mm / min or less, the molding efficiency is low and not practical. On the other hand, when it is 600 mm / min or more, an uncured portion may be formed in the obtained molded product, and many voids may be generated inside the molded product.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 In accordance with the present invention, as shown in the lower mold of FIG. 1, a molding groove having a depth of 3 mm, a width of 24 mm and a length of 900 mm is provided, and the molding groove is orthogonal to the molding groove. Section depth 3mm, width 24m
There are 7 gas vent holes of m and length 60 mm (corresponding to the width of the side wall of the forming groove) on each side of the forming groove.
Further, a pair of molds having seven passages for the refrigerant (water at room temperature) on each side of the molding groove was prepared in the vicinity of each gas vent hole, and these molds were used as upper and lower molds. Using such a mold, the cooling water was circulated through the refrigerant passage to cool the gas vent hole, and the glass fiber reinforced phenolic resin was subjected to pultrusion molding. The molding materials and molding conditions are shown below.

Molding material phenol resin: alkali resol type, average molecular weight 18
5, viscosity 45 Pas, pH 8.1, non-volatile content 79% Internal mold release agent: Phosphate ester type (Moldwise Co., Ltd.) Glass roving: R4450TTFOS, count 445
0g / km, Asahi Fiber Glass Co., Ltd. Glass mat: Continuous Strand Matt M8644, Owens Corning

As shown in Table 1, using the molding material prepared from the above, the mold temperature was 165 ° C both above and below, and the drawing speed was 30.
It was set to 0 mm / min. Table 2 shows the physical properties of the obtained molded product.

Comparative Example 1 Using the same molding material and mold as in Example 1, pultrusion molding was carried out without cooling the gas vent holes.

Comparative Example 2 The same molding material as in Example 1 was used, but a mold having neither vent holes nor cooling water passages was used, and a glass fiber reinforced phenol resin was used under the same conditions. Pultrusion molding was performed.

In Comparative Example 1, the resin leaked into the degassing hole during the molding and solidified, so that the molding had to be interrupted at last. In Comparative Example 2, the condensation gas filled the molding groove, and molding itself was impossible.

Example 2 Molding was carried out under the same conditions as in Example 1 except that the molding materials shown in Table 1 were used to obtain moldings shown in Table 2.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

The mold according to the present invention has a molding groove in the drawing direction, has a gas vent hole communicating with the molding groove from the outside of the mold, and is close to the gas vent hole in the mold. And, since it has a refrigerant passage for cooling the gas vent hole to a temperature not higher than the curing reaction temperature of the resin, by using such a mold, the fiber reinforced plastic drawing which forms the matrix by condensation polymerization is drawn out. If molding is performed, the condensation gas generated by the curing reaction of the resin is continuously removed from the mold, and the gas vent hole is not clogged with the resin, and the fiber reinforced resin has no defects such as voids. The molded product can be continuously and efficiently pultruded.

[Brief description of drawings]

FIG. 1 is a perspective view showing a preferable example of a mold used in the present invention in which an upper mold and a lower mold are separately shown.

FIG. 2 is a perspective view showing another preferred example of the mold used in the present invention, showing an upper mold and a lower mold separately.

FIG. 3 is a perspective view showing a metal mold formed by combining the upper mold and the lower mold shown in FIG. 1.

FIG. 4 is a cross-sectional view showing a Y-shaped tube for supplying a coolant into a mold.

FIG. 5 is a partial cross-sectional plan view showing a mold in which the Y-shaped tube is attached to the mold to cool the gas vent holes of the mold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mold, 2 ... Upper mold, 3 ... Lower mold, 4 and 5 ... Split mold mating surface, 6 ... Molding groove, 7 ... Gas vent hole, 8 ... Mold inlet,
9 ... Mold outlet, 10 ... Refrigerant passage, 11 ... Screw hole, 12 ...
Partition plates, 13, 14, 16, 18, 19 ... Y-shaped tube, 1
5 ... Y pipe inlet pipe, 17 ... Y pipe outlet pipe, 20 ... Connection pipe.

Claims (4)

[Claims] 1. A mold having a molding groove in the drawing direction and provided with a gas vent hole communicating with the molding groove from the outside, and a molding made of a reinforced fiber material impregnated with resin at the inlet of the mold. Generates while the material is guided, passed through the molding groove, hardened, drawn out from the outlet of the mold, while circulating the refrigerant in the mold, cooling the gas vent hole, and hardening the molding material. The method for pultrusion molding of a fiber-reinforced condensation-polymerized resin, characterized in that the condensation gas to be discharged is released from the gas vent hole to the outside of the mold. 2. A molding groove extending from the inlet of the mold in the drawing direction to the outlet, a gas vent hole communicating with the molding groove from the outside, and a coolant passage for cooling the gas vent hole. Having a molding material made of a reinforced fiber material impregnated with a resin at the inlet, passing through the molding groove, curing, and withdrawing from the outlet, a refrigerant is circulated through the passage, and the gas vent hole is formed. A mold for pultrusion molding of a fiber-reinforced condensation-polymerized resin, characterized in that a condensation gas generated during curing of the molding material is allowed to escape to the outside of the mold while cooling. 3. A mold comprises a pair of an upper mold and a lower mold, a molding groove is formed on a mating surface of the pair of molds in a drawing direction, and at least one of the mating surfaces is molded from the outside of the mold. The mold according to claim 2, wherein a groove communicating with the mold is formed as a gas vent hole. 4. A mold comprises a pair of an upper mold and a lower mold, and a molding groove is formed in a drawing direction on a mating surface of the pair of molds, and at least one of the pair of molds is molded from the outside of the mold. The mold according to claim 2, wherein the through hole communicating with the groove is formed as a gas vent hole.