JPH06192360A - Resorcin-modified phenolic resin composition and its frp - Google Patents

Abstract

(57) [Summary] [Purpose] A resin composition having a relatively long pot life, good workability, and moldable at a relatively low temperature, and excellent mechanical properties and flame retardancy molded using the same. Of fiber reinforced plastics (FRP) having properties. [Structure] A resin composition containing a resorcin-modified phenol resin obtained by first-reacting phenols and formaldehyde in the presence of an alkali catalyst, then adding resorcins and formaldehyde, and secondarily reacting them. And fiber-reinforced plastics (FR) having excellent mechanical properties and flame retardancy molded using the same
P).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resorcin-modified phenolic resin composition and its FRP.

[0002]

BACKGROUND OF THE INVENTION Phenolic resins widely used as industrial resins are excellent in flame retardancy and heat resistance, and
Since it has good workability, it has been attracting attention as a fiber-reinforced plastic. Various methods have been devised and utilized for the curing method of the phenol resin, but as a method of curing at a relatively low temperature, there are a urethane curing method, an acid curing method and the like. Although the urethane curing method can be cured at room temperature, it has a weak point that the urethane bond is weak in heat resistance. On the other hand, the acid curing method using an acidic substance such as paratoluene sulfonic acid and xylene sulfonic acid as a curing agent is good in curing at room temperature and heat resistance, but the pot life after addition of the curing agent is remarkably short. Workability becomes a problem. In this case, there is a case where the resin is pumped into the mold by a resin supply pump, and molding is performed using a closed mold system in which the resin is impregnated with the fiber reinforcement. In this system, since the curing agent is added just before the resin is injected,
There is almost no influence of the pot life of the resin on the molding work. However, in this closed mold system, the impregnation mechanism of the closed mold system is more complicated than that of the open mold system conventionally used for pultrusion molding using polyester resin, vinyl ester resin and epoxy resin. ) There are drawbacks such as difficulty in finding appropriate molding conditions, (b) difficulty in adapting to thick molded products, and (c) high cost of the system itself. Further, the use of the acid catalyst cannot corrode the mold and the acid remains in the molded product, so that the metal component cannot be used as a joining material for the fiber reinforced plastic. On the other hand, liquid resorcin resin is widely used as a binder such as an adhesive for woodworking. However, since resorcin is expensive in cost, its intended use is almost limited. As a cost reduction method, modification with phenol has been studied and many resins are commercially available. Originally, it is known that the reaction rate of resorcin and formaldehyde is 2.5 times or more as high as the reaction rate of phenol and formaldehyde. That is, in the method for producing a resorcin-modified phenol resin by mixing resorcin and phenols, the addition / condensation reaction rates are different from each other. However, how well this modification is carried out has a great effect on properties such as the curing rate of the resorcin-modified phenolic resin and the strength of the fiber-reinforced product. The following three methods are generally considered as the method for producing the resorcin-modified phenol resin. (1) A method of adding resorcin to a phenol resin. (2) A method in which a phenol resin and a resorcin resin are separately prepared and then mixed. (3) A method of adding phenol to the resorcin resin. The method of mixing resorcin (1) is a mixture with resorcin to which resorcin is post-added after the completion of the reaction of the phenol resin, and it is difficult to make it uniform during curing. (3)
However, since it is a mixture with phenol, uniformization is difficult. Moreover, in the method of (2),
A mixture of a resorcin resin and a phenol resin, which is prepared by preliminarily reacting both with each other, and is mixed. JP-A-2-215879
Although a method such as that disclosed in Japanese Patent No. 6-96242 has been devised, it has a problem in uniformity during curing and is uneconomical because it is manufactured in two steps. Furthermore, after mixing phenol and resorcin in advance,
Special table to react with formaldehyde 2-504400
Although there is also the method described in No. 1, the uniform reaction is difficult due to the difference in the reaction rate for the above reason.

[0003]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems, and has a relatively long pot life, good workability, and a resin composition which can be molded at a relatively low temperature, and the same. The present invention relates to a fiber reinforced plastic (FRP) having excellent mechanical properties and flame retardancy, which is molded by using.

[0004]

[Means for Solving the Problems] The first aspect of the present invention is to subject phenols and formaldehyde to a primary reaction in the presence of an alkali catalyst, and then add resorcins and formaldehyde,
The present invention relates to a resin composition containing a resorcin-modified phenol resin obtained by a secondary reaction. A second aspect of the present invention comprises a resorcinol-modified phenolic resin obtained by first-reacting phenols and formaldehyde in the presence of an alkaline catalyst, then adding resorcinols and formaldehyde, and secondarily reacting the same with a curing agent thereof. The present invention relates to a fiber reinforced plastic, which is obtained by impregnating a fiber composition with a resin composition and curing the resin composition at 70 to 110 ° C. using a pultrusion molding machine.

The phenols used in the present invention include phenol; alkyl-substituted or alkoxy-substituted phenols such as cresol, o- or p-methoxyphenol, and two or more phenol nuclei bonded with or without an alkyl chain. For example, bisphenol A, bisphenol F, etc. are used alone or in combination of two or more. The resorcins used in the present invention refer to resorcin, alkyl-substituted or alkoxy-substituted resorcin. The liquid resorcin modified phenolic resin of the present invention,
It is made in a one-step process in which phenols and formaldehyde are preliminarily (primarily) reacted in the presence of an alkaline catalyst, then resorcinol and formaldehyde are added, and the secondary reaction is carried out in the same catalyst. All alkali catalysts used in the reaction can be used. Examples thereof include basic salts such as sodium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide. These alkali catalysts may be used alone or in combination of two or more.

The resorcin-modified phenol resin obtained by the present invention can be rapidly cured at a relatively low temperature of 70 to 110 ° C. by using formaldehyde, paraformaldehyde or a mixture of both as a curing agent, and fiber reinforced. When it is made of plastics, it has excellent strength. In addition, when using a normal pultrusion molding machine, if the mold temperature is lower than 70 ° C, the molded product becomes uncured and not only requires a long time post-cure, but also the residual strain after curing causes a deflation in the drawing direction. Causes a large sled. When the mold temperature is higher than 110 ° C., the surface of the molded product becomes uneven. As the pultrusion molding machine, one having an open mold system, a closed mold system, or a system combining them can be used.

The resorcin-modified phenolic resin of the present invention contains, in addition to a curing agent, calcium carbonate, clay, talc, aluminum hydroxide, barium sulfate, calcium sulfate, and other fillers, metal soaps, waxes, and the like. The resin composition is prepared by adding the mold releasing agent. The fiber reinforcement used in the present invention is a chopped strand mat, a continuous strand mat, a roving, a roving cloth, a blind cloth and the like made of glass fiber, carbon fiber, synthetic fiber such as aramid fiber. In addition to this, a surfacer made of polyester, acrylic, rayon or the like may be used for the purpose of smoothing the surface of the molded product and improving durability. Further, as various fiber reinforcing materials, those subjected to usual surface treatment such as silane treatment and boron treatment can be used. The molded product obtained in the present invention, since the acid does not remain in the molded product, it can be joined or processed using a metal member, the mechanical strength,
Excellent flame resistance and heat resistance. Especially in flame retardancy, J
Passes Class 2 flame retardancy stipulated in IS A 1321 (flame retardancy test method for building interior materials and construction methods). Therefore,
The molded product can be used as a construction material for ducts, ceilings, interior / exterior materials, etc. that require flame retardancy.

[0008]

【Example】

Example 1 1 mol of phenol was added to a 37% aqueous formaldehyde solution of 0.1%.
It was dissolved in 5 mol, 0.4 mol of 50% sodium hydroxide was added as an alkali catalyst, and a reflux (primary) reaction was carried out at a temperature of 80 ° C. for 30 minutes. Subsequently, 1 mol of resorcin and 0.85 mol of 37% aqueous formaldehyde solution were added while cooling to 50 ° C. or lower, and a secondary reaction was performed at a temperature of 60 ° C. for 60 minutes, and then condensed water was removed under reduced pressure. A liquid resorcin-modified phenolic resin having a viscosity of 5 poise was obtained. The resin thus obtained has a resin content of 70%, a pH of 7.5,
It was a weakly alkali-curable resorcin-modified phenol resin having a water content of 23%.

Example 2 Table 1 compares the resin composition obtained in Example 1 of the present invention with the acid-curing resin generally used for FRP in terms of the viscosity increase ratio of the resin containing a curing agent. .

[Table 1] As a result, the pot life of the resin obtained in this example is longer than the pot life of the comparative product, and therefore the workability is good. Further, the example products can be gel-cured at 80 ° C. and can be molded at a relatively low temperature.

Example 3 A resin composition was prepared by kneading 20 parts of clay as a filler, 15 parts of paraformaldehyde as a curing agent, and 2 parts of a releasing agent with the resorcin-modified phenol resin of Example 1. A glass fiber reinforcing material was impregnated with the prepared resin composition, and a board having a thickness of 3 mm and a width of 220 mm was molded using a pultrusion molding machine. At that time, the temperature of the mold was 95 ° C., and the drawing speed was 15 cm / min. After the pultrusion molding, the molded product was post-cured at 125 ° C. for 3 hours. The mechanical properties of the molded product are shown in Table 2. For comparison, 3 mm molded with unsaturated polyester resin (UP)
The mechanical properties of the board (control) are shown. Mechanical properties of Phenol FRP (3mm board)

[Table 2]

Example 4 20 parts of aluminum hydroxide [Al ₂ (OH) ₃ ] or clay as a filler, 15 parts of paraformaldehyde as a curing agent and 2 parts of a releasing agent were added to the resorcin-modified phenol resin of Example 1. Parts were kneaded to prepare a resin composition. Using the prepared resin composition, a board having a thickness of 3 mm and a width of 220 mm was molded in the same manner as in Example 2. Regarding molded products, surface test (flame retardancy class 2) according to JIS A 1321 (flame retardancy test method for building interior materials and construction method) and JIS A 7201 (combustion test method for polymer materials by oxygen index method) The oxygen index was measured according to the above. The results are shown in Table 3. Flame resistance of Phenol FRP (3mm board)

[Table 3]

[0012]

[Effect] The resin composition of the present invention has a relatively long pot life, has good workability, and can be molded at a relatively low temperature. FRP using the same has excellent mechanical properties and flame retardancy. Have sex.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Tachikawa 1-2-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Sumitomo Dures Co., Ltd.

Claims (2)

[Claims] 1. A resin comprising a resorcin-modified phenol resin obtained by first-reacting phenols and formaldehyde in the presence of an alkali catalyst, then adding resorcins and formaldehyde, and secondarily reacting them. Composition. 2. A resin composition containing a resorcin-modified phenol resin obtained by first-reacting phenols and formaldehyde in the presence of an alkali catalyst, then adding resorcins and formaldehyde, and secondarily reacting them with a curing agent therefor. Fiber reinforced plastics, characterized in that the fiber reinforced material is impregnated with the material and cured at 70 to 110 ° C. using a pultrusion molding machine.