JPH08269297A - Phenolic resin molding material - Google Patents

Abstract

PURPOSE: To make a phenolic resin molding material less warped or less deformed, by mixing a molding material containing as a binder a liquid resol type phenolic resin with a shrinkage lowering agent, such as polyvinyl acetate and a flame retarder, such as Al(OH)3 . CONSTITUTION: An aldehyde is reacted with a phenol in the presence of an alkali catalyst to obtain a liquid resol type phenolic resin having a viscosity of 1 to 6P at 25 deg.C, a molecular weight of 140 to 400, a pH of 5 to 11, a water content of 1 to 30wt.%, and a nonvolatile content of 59 to 85wt.%. The liquid resol type phenolic resin is admixed and kneaded with a shrinkage lowering agent, such as polyvinyl acetate having a degree of polymerization of 600 or more in an amount of 2 to 30% based on the nonvolatile content in the phenolic resin, a flame retarder, such as Al(OH)3 in an amount of 100 to 450wt.% based on the nonvolatile content, a curing adjuster, such as Ca(OH)2 , an internal releaser, such as zinc stearate, etc., to get a resin paste mixture. The resin paste mixture is sprinkled over a fiber reinforcing material, such as glass fiber to impregnate the fiber reinforcing material with the resin paste mixture, and the fiber reinforcing material is formed into a sheet, followed by aging to obtain a phenolic resin molding material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid resol-type phenol resin molding material used for various molded articles such as building members, vehicle members and automobile members.

[0002]

2. Description of the Related Art In recent years, in response to the demand for weight reduction of building members, vehicle members, and automobile members, phenol resin molding materials using a phenol resin excellent in flame retardancy and low smoke generation as a binder have been developed. Research and development are actively conducted. As an example, in Japanese Patent Laid-Open No. 62-96556,
It is characterized by containing (a) a resol type phenolic resin, (b) a hydroxide or oxide of an alkaline earth metal, or a silane compound, and (c) a filler mixture or microspheres composed of clay and talc. Phenolic resin molding materials are disclosed.

However, a drawback of the phenol resin molding material is a problem of dimensional stability such as warpage and deformation caused by a condensation reaction during heat and pressure molding. Therefore, lactones are used to improve the dimensional stability. As an example, in JP-A-63-291945, (a) a resole type phenolic resin, (b) a hydroxide or oxide of an alkaline earth metal, or a curing agent selected from the group of silane compounds,
A low-shrinkage phenolic resin molding material characterized by comprising (c) a filler and (d) a lactone is disclosed.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made as a result of various studies in order to solve the problems such as warpage and deformation which were the drawbacks of conventional phenol resin molding materials.
It is an object of the invention to provide a phenol resin molding material having low shrinkage and high flame retardancy, which does not impair workability during molding, has little warpage and deformation of a molded product after molding. .

[0005]

The essential components of the low shrinkage and highly flame retardant phenolic resin molding material of the present invention are polyvinyl acetate as a low shrinkage agent and aluminum hydroxide as a flame retardant. is there. The blending amount of polyvinyl acetate is 2 to 3 relative to the non-volatile content of the liquid resol type phenol resin.
0% by weight. The non-volatile content described here is JIS
It is obtained by the method specified in K 6833. The addition of polyvinyl acetate as a low-shrinking agent is already known in the case of unsaturated polyester resin molding compositions. On the other hand, in the case of a phenol resin molding material, JP-A-3-17
An example is found in Japanese Patent No. 4465, but the flame retardancy is lowered as in the case of the unsaturated polyester resin molding material. Therefore, a phenol resin molding material having low shrinkage and high flame retardancy can be obtained only when used in combination with aluminum hydroxide. This point is a feature of the present invention, and has been found by the present inventors.

The amount of aluminum hydroxide, which is another essential component of the present invention, is 100 to 450% by weight based on the nonvolatile content of the liquid resol type phenol resin.
Here, aluminum hydroxide also serves as a filler. As an example of blending aluminum hydroxide to obtain a non-combustible composite material, JP-A-50-3156 and JP-A-50-
3183, JP-A-50-3451, JP-A-50-5471, JP-A-50-26852, JP-A-58-149939, and JP-A-3-
Although there are Japanese Patent No. 189110 and the like, it was not possible to obtain a molded product that has both low shrinkage and high flame retardancy.

The blending amount of polyvinyl acetate used as a low-shrinking agent in the present invention is 2 to 30% by weight, preferably 5 to 20% by weight, based on the nonvolatile content of the liquid resol type phenol resin. . If the blending amount is less than 2% by weight, the effect of low shrinkage cannot be sufficiently obtained, and if it exceeds 30% by weight, the flame retardancy is impaired. Further, it is preferable to use polyvinyl acetate having a polymerization degree of 600 or more. When the degree of polymerization is less than 600, it takes a long time to age the molding material. In addition, regarding the terminal group, when comparing those having a partial carboxylic acid group at the terminal with those having no carboxylic acid group, both are effective in low shrinkage,
The one having a carboxylic acid group partially in the terminal group is more effective.

The amount of aluminum hydroxide used as a flame retardant / filler in the present invention is 100 to 450% by weight based on the nonvolatile content of the liquid resol type phenol resin. If the blending amount is less than 100% by weight, it is difficult to obtain good flame retardancy. If the blending amount exceeds 450% by weight, the viscosity of the resin paste at the time of manufacturing the molding material is too high and it is difficult to make it uniform, so that a smooth and sufficient strength is obtained. It becomes difficult to obtain a molded article having the same. The liquid resol type phenolic resin which is the matrix used in the present invention is prepared by reacting phenols with an excess molar ratio of aldehydes in the presence of an alkaline catalyst. The molar ratio of aldehydes to phenols is usually 0.8 to 3.0, preferably 1.1 to 2.5. As the alkaline catalyst, sodium hydroxide, potassium hydroxide, ammonia, calcium hydroxide, barium hydroxide or the like is used, but it is not particularly limited. The liquid resol type phenol resin usually has a viscosity of 1 to 6 p / 25 ° C., a molecular weight of 140 to 400, a pH of 5 to 11, and a water content of 1 to 30.
%, And the non-volatile content is in the range of 50 to 85% according to the method specified in JIS K6833.

The fillers used in the present invention include calcium carbonate, barium sulfate, talc, clay, silicon oxide and the like in addition to the above-mentioned aluminum hydroxide. These are used with aluminum hydroxide. In the phenol resin molding material of the present invention, calcium hydroxide, magnesium oxide or the like is used as a curability adjuster, and generally used zinc stearate or the like is used as an internal release agent.

The fiber reinforcement used in the present invention is
The fibers are glass fibers, carbon fibers, aramid fibers and the like, and the fiber length thereof is usually 1.5 to 50 mm. Especially when compounded into a sheet-shaped molding material, it is about 10-3.
0mm, about 1.5-1.5 when compounded in bulk molding material
15 mm is preferable. The amount of the fiber reinforcement used is 5 to 70% by weight based on the whole molding material. To produce, for example, a sheet-shaped molding material using the molding material of the present invention thus obtained, liquid resol-type phenol resin is added with polyvinyl acetate as a low shrinking agent and aluminum hydroxide as a flame retardant / filler. Further, a curability modifier and an internal release agent are added and mixed to obtain a resin paste. Next, in the same manner as in the method for producing a general unsaturated polyester resin sheet-shaped molding material, fibers such as glass roving cut into a certain length by a sheet impregnating machine are sprinkled and impregnated with a resin paste to form a sheet. Roll up. The obtained sheet material is aged in an aging furnace at room temperature to 50 ° C. for 2 to 5 days, and if necessary, further aging to obtain a molding material that is easy to handle.

In order to produce, for example, a bulk molding material using the molding material of the present invention, a conventional kneading device (eg, kneader, planetary mixer, etc.) is used, and a liquid resol type phenol resin is used as a polycondensation agent as a low shrinking agent. Vinyl acetate, flame retardant / aluminum hydroxide as a filler, and if necessary, a curability modifier, an internal mold release agent, etc. are mixed, and then a fiber reinforcement is added, mixed, and then packed in a bag.

The phenol resin molding material thus obtained can be easily molded by pressurizing at high temperature, and various molded products used as members for buildings, members for vehicles and members for automobiles can be manufactured. You can

[0013]

EXAMPLES The present invention will be specifically described below with reference to examples. The invention is not limited by these examples. In addition, "part" and "%" described here
Unless otherwise specified, all are "parts by weight" and "% by weight".

Examples 1 to 5 Various phenolic resin sheet-shaped molding materials were prepared in the following manner to obtain molded products. First, liquid resol type phenolic resin (non-volatile content 75%) is used in the proportions shown in Table 1, polyvinyl acetate as a low shrinkage agent, aluminum hydroxide, calcium carbonate, talc, clay as a flame retardant / filler, and further cured. Calcium hydroxide as a sex modifier, zinc stearate as an internal mold release agent, and, if necessary, methanol to reduce the viscosity are mixed, and mixed by a mixer until homogenous for about 30 minutes. A paste mixture was obtained. A glass fiber having a fiber length of 25 mm was sprinkled on the obtained resin paste mixture while adjusting the weight ratio of the resin paste mixture to 72:28 by a sheet impregnating machine to impregnate the glass fiber with the resin paste mixture. Two polymer films were formed into a sandwich type sheet. The film should be peeled off at 45 ° C for 3
Aged for days. Next, mold temperature 150 ℃, pressure 100kg
After depressurizing for 15 seconds under the condition of 1 / cm ² , degassing is carried out by 1
I've done it. Subsequently, compression molding was performed for 5 minutes at the same temperature and the same pressure to obtain a flat plate molded product of 30 × 30 × 3 mm.

Comparative Examples 1 to 3 Various phenolic resin sheet molding materials were prepared in the following manner to obtain molded products. First, at the ratio shown in Table 1,
To the liquid resol type phenol resin (non-volatile content 75%), polyvinyl acetate as a low shrinking agent, aluminum hydroxide and talc as a filler, calcium hydroxide as a curability adjusting agent, and zinc stearate as an internal releasing agent are added, If necessary, methanol for reducing the viscosity was added and mixed with a mixer for about 30 minutes to obtain a resin paste mixture. Hereinafter, a flat plate molded product of 30 × 30 × 3 mm was obtained in the same manner as in the examples.

<Measurement and Evaluation Method of Warp> Warp is JIS K
It measured according to 6911. The results obtained are shown in Table 1. As is clear from these data, it was confirmed that the molded product to which the polyvinyl acetate was added had less warpage and deformation and improved low shrinkage as compared with the molded product to which no polyvinyl acetate was added. <Evaluation Method of Flame Retardancy> The flame retardance was measured according to the “Ministry of Transport Law” specified in Iron Transport No. 81 of the Ministry of Transport. Table 1 shows the obtained results.
Shown in As is clear from these data, it was confirmed that the molded product to which aluminum hydroxide was added had improved flame retardancy as compared with the molded product to which no aluminum hydroxide was added.

[0017]

[Table 1]

[0018]

According to the present invention, it is possible to provide a low-shrinkage and highly flame-retardant phenol resin molding material in which warpage, deformation and the like, which are drawbacks of conventional phenol resin molding materials, are improved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Naoko Inoue 2-5-8 Higashi-Shinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. (72) Shunsuke Irie 2-5-8 Higashi-Shinagawa, Shinagawa-ku, Tokyo No. Sumitomo Durez Co., Ltd.

Claims (4)

[Claims] 1. A phenolic resin characterized by comprising polyvinyl acetate as a low-shrinking agent and aluminum hydroxide as a flame retardant as essential components in a molding material using a liquid resol-type phenolic resin as a binder. Molding material. 2. The blending amount of polyvinyl acetate is 2 to 30% by weight with respect to the nonvolatile content of the liquid resol-type phenol resin.
The phenolic resin molding material according to claim 1, which is 3. The phenol resin molding material according to claim 1, wherein the average degree of polymerization of polyvinyl acetate is 600 or more. 4. The blending amount of aluminum hydroxide is 100 to 4 with respect to the non-volatile content of the liquid resol type phenol resin.
The phenol resin molding material according to claim 1, which is 50% by weight.