JP2002256136A - Phenolic resin molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenolic resin molding material improved in flame retardancy without detriment to heat resistance, electrical properties, and mechanical properties by compounding a phenolic resin molding material with a phosphorus flame retardant and silica gel. SOLUTION: This material is a phenolic resin molding material which essentially consists of a phenolic resin, an organic filler and/or an inorganic filler, and a flame retardant being a phosphorus one, and silica gel and in which, desirably, the phosphorus flame retardant is a mixture which comprises red phosphorus, aluminum hydroxide, and a phenolic resin and in which 40-100 pts.wt. aluminum hydroxide is used per 100 pts.wt. red phosphorus, and 90-150 pts.wt. phenolic resin is used per 100 pts.wt. red phosphorus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenolic resin molding material having excellent flame retardancy without impairing heat resistance, electrical properties and mechanical properties. The phenolic resin molding material of the present invention is used for electric / electronic parts such as breakers, magnet switches, bobbins, and switch cases.

[0002]

2. Description of the Related Art Among thermosetting resins, phenol resins are excellent in various points such as heat resistance, mechanical properties, moldability, and cost, and are used in various applications such as molding materials and laminates. Among them, phenolic resin molding materials used for electric and electronic parts are required to have high reliability,
In particular, in accordance with recent miniaturization and thinning, a molded article having a smaller thickness is required to have flame retardancy.

In general, as a method of improving the flame retardancy, addition of inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, zinc borate and the like can be mentioned. However, when the amount is extremely increased, the mechanical properties and moldability deteriorate. Tend to. Also,
Addition of red phosphorus, which is a phosphorus compound having a high flame-retardant effect, can be mentioned, but when the amount is extremely increased, mechanical properties and electrical properties tend to decrease. From these points, it is necessary to improve the flame retardancy without increasing the amount of the phosphorus compound used.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a phenol resin which is excellent in flame retardancy without impairing heat resistance, electric properties and mechanical properties by blending a phosphorus-based flame retardant and silica gel into a phenol resin molding material. A molding material is provided.

[0005]

The present invention is characterized in that (1) a phenol resin, an organic filler and / or an inorganic filler, and a phosphorus-based flame retardant and silica gel as essential components as flame retardants. Phenolic resin molding material,
(2) The phosphorus-based flame retardant is a mixture of red phosphorus, aluminum hydroxide, and a phenol resin, and contains 40 to 100 parts by weight of aluminum hydroxide and 90 to 150 parts by weight of a phenol resin with respect to 100 parts by weight of red phosphorus. (3) 0.1 to 5 parts by weight of a phosphorus-based flame retardant as a red phosphorus component, and 1 to 20 parts of silica gel, based on 100 parts by weight of the entire molding material. Item (1) or (2), characterized by containing parts by weight.
The phenolic resin molding material described in the item.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The phenolic resin used in the present invention is usually a novolak type phenolic resin or a resol type phenolic resin, and these may be used in combination, and are not particularly limited. As these phenolic resins, solid ones having a number average molecular weight of 500 to 1200 are preferably used in view of the mechanical properties of the molded product, moldability, and processability into a molding material. Further, it may be modified with xylene, alkylphenol or the like. When a novolak-type phenol resin is used, hexamethylenetetramine is used as a curing agent. The amount of hexamethylenetetramine is based on the novolak type phenol resin.
It is 10 to 20% by weight similarly to the usual phenolic resin molding material. The amount of the phenolic resin, including the amount of hexamethylenetetramine, is 2% based on the entire molding material as in the case of the ordinary phenolic resin molding material.
0 to 55% by weight.

The present invention is characterized in that a phosphorus-based flame retardant and silica gel are used in combination as a flame retardant. When a phosphorus-based flame retardant is used in combination with silica gel, the chemical mechanism is not clear, but a superior flame-retardant effect is obtained due to a synergistic effect as compared with the case where each is used alone. Therefore, by using these in combination, excellent flame retardancy can be obtained without impairing heat resistance, electrical properties, and mechanical properties. As the phosphorus-based flame retardant, a mixture of red phosphorus, aluminum hydroxide and a phenol resin is preferably used. The phosphorus-based flame retardant having such a composition can be handled as a non-dangerous substance, and can effectively achieve flame retardation with a small amount. Similar effects can be obtained when red phosphorus alone is used as a phosphorus-based flame retardant, but care must be taken during handling and storage because red phosphorus belongs to dangerous substances.

When a mixture of red phosphorus, aluminum hydroxide and a phenol resin is used as the phosphorus-based flame retardant, aluminum hydroxide is used in an amount of 40 to 100 parts by weight of red phosphorus.
Those containing 100 parts by weight and 90 to 150 parts by weight of a phenol resin are preferred. If the amount of aluminum hydroxide or phenolic resin is less than this range, the fire and ignition test under the Fire Service Law cannot be cleared. If the mixture falls within this range, it meets the fire and ignition test under the Fire Service Law and does not fall under the category of dangerous goods. If the amount of aluminum hydroxide or phenolic resin is larger than this range, there is no problem in terms of flame retardation, but it is necessary to use a large amount of the phosphorus-based flame retardant, which is not efficient.

The amount of the phosphorus-based flame retardant is 10
The phosphorus-based flame retardant is used as a phosphorus component in an amount of 0 part by weight.
It is 1 to 5 parts by weight, preferably 0.1 to 2 parts by weight. If the phosphorus component of the phosphorus-based flame retardant is less than 0.1 part by weight, the effect on flame retardancy is small, and if it exceeds 5 parts by weight, mechanical properties and electrical properties are liable to deteriorate.

The silica gel used in the present invention is of various types depending on the difference in the chemical structure of silicon dioxide (SiO ₂ ) as a main component.
The type having a large specific surface area and having a hydroxyl group in the pores and on the surface has high adsorption performance at low humidity and is suitable for the purpose of the present invention. ^2. Preferably, the oil absorption is 70 to 250 ml per 100 g. The amount of silica gel is 1 to 20 with respect to 100 parts by weight of the whole molding material.
Parts by weight, preferably 5 to 15 parts by weight. If the silica gel content is less than 1 part by weight, the flame retardancy tends to decrease, and if it exceeds 20 parts by weight, the mechanical properties tend to decrease.

The organic filler used in the present invention is not particularly limited, and examples thereof include wood flour, pulp, laminated board flour, plywood flour, and coconut husk flour. Although the particle size is not particularly limited, 80-mesh fully-passed product is preferable from the appearance of the molded product. If it is coarser than 80 mesh, the surface smoothness of the molded product tends to decrease.

The inorganic filler used in the present invention is not particularly restricted but includes, for example, calcium carbonate, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, magnesium oxide, clay, diatom, talc and the like. Although the particle size is not particularly limited, it is preferable to use an 80-mesh whole product for the same reason as the organic filler.

In the present invention, a fibrous inorganic filler can be used. Typically, there is glass fiber. The glass fiber is not particularly limited, and examples thereof include E glass. The shape is not particularly limited, but a glass fiber diameter of 5 to 25 μm and a fiber length of 0.5
Those having a thickness of 6 mm are preferred in view of the mechanical properties of the molded article and the ease of forming a molding material.

The compounding ratio of these organic fillers and inorganic fillers is the same as that of ordinary phenolic resin molding materials, including silica gel used as a flame retardant and calcium hydroxide as a hardening aid, including calcium hydroxide. It is preferably 40 to 70% by weight based on the whole molding material.

In the present invention, antimony trioxide, aluminum hydroxide, magnesium hydroxide, boric acid, zinc borate and the like can be used as a flame retardant auxiliary. Considering the flame retardant effect and the effect on the environment, aluminum hydroxide, boric acid, and zinc borate are preferred.

The phenolic resin molding material of the present invention is mixed with the raw materials and the ingredients described above, and further added with raw materials such as a curing agent, a release agent, a pigment and a silane coupling agent, and is heated and twin-screw extruded. It is obtained by kneading and pulverizing or granulating by a usual method using a machine or the like.

[0017]

EXAMPLES Formulations shown in Table 1 (combination ratios are shown by weight%)
, And kneaded with a heating roll at 90 ° C. for 6 minutes to produce a phenolic resin molding material. Transfer molding (mold temperature: 175 ° C, curing time: 1)
The test piece was molded at 80 seconds), and the mechanical properties, electrical properties, heat resistance and flame retardancy were measured.

[Table 1]

Description of Table 1) Phenol resin: Novolac type phenol resin "A-1082" manufactured by Sumitomo Akita Bakelite Co., Ltd. 2) Hexamethylenetetramine: curing agent 3) Wood flour: 80 mesh pass 4) Clay: manufactured by Tsuchiya Kaolin Industries NN kaolin clay ”5) Phosphorus-based flame retardant: The ratio of red phosphorus / aluminum hydroxide / phenol resin is 35 parts by weight / 25 parts by weight / 40.
6) Red phosphorus: "NOVA Excel 150" manufactured by Rin Kagaku Kogyo
(Red phosphorus content: 75%) 7) Silica gel: average particle size 4 μm, specific surface area 700 m ²
/ G, oil absorption 95 ml (per 100 g) 8) Calcium hydroxide: curing aid 9) Release agent: stearic acid 10) Colorant: spirit black

(Measurement method) 1) Flexural strength, deflection temperature under load, insulation resistance: JIS K
According to 6911 2. Flame retardancy: UL94 vertical method

In Examples 1 and 2, a phosphorus-based flame retardant and silica gel were used in combination, and in Example 3, red phosphorus was used as the phosphorus-based flame retardant, which was compared with Comparative Example 3 in which no flame retardant was used. In each case, good flame retardancy is obtained without impairing the heat resistance, electrical properties, and mechanical properties. On the other hand, Comparative Example 1
In Comparative Example 2, only the silica-based flame retardant was used as the flame retardant, and in Comparative Example 2, only silica gel was used as the flame retardant.

[0021]

According to the present invention, there is provided a phenol resin molding material comprising a phenol resin, an organic filler and / or an inorganic filler, and a phosphorus-based flame retardant and silica gel as flame retardants as essential components. According to the present invention, it is possible to obtain a phenol resin molding material having excellent flame retardancy without impairing heat resistance, electrical properties, and mechanical properties, and to easily manufacture molded articles of electric / electronic parts that require those properties. Therefore, it is suitable as an industrial phenolic resin molding material. In particular, when a mixture of red phosphorus, aluminum hydroxide, and a phenol resin is used as a phosphorus-based flame retardant, a molding material having an excellent flame retardant effect can be obtained with a small amount.

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Claims (3)

[Claims] 1. A phenolic resin molding material comprising a phenolic resin, an organic filler and / or an inorganic filler, and a phosphorus-based flame retardant and silica gel as flame retardants as essential components. 2. The phosphorus-based flame retardant is a mixture of red phosphorus, aluminum hydroxide and a phenolic resin.
2. The phenolic resin molding material according to claim 1, which contains 40 to 100 parts by weight of aluminum hydroxide and 90 to 150 parts by weight of a phenol resin with respect to 00 parts by weight. 3. The composition according to claim 1, wherein 0.1 to 5 parts by weight of a phosphorus-based flame retardant and 1 to 20 parts by weight of silica gel are contained based on 100 parts by weight of the whole molding material. A phenolic resin molding material as described above.