JPS5952908B2 - Flame retardant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flame-retardant resin composition for use in laminates with excellent flame retardancy, and its purpose is to reduce the flame retardance caused by the triazine nuclei held in the triazine-based amino resin-modified phenolic resin. A resin composition that can effectively utilize the flame effect and provide a laminate with particularly excellent flame retardancy, which has heat resistance, electrical properties, and punching workability without significantly impairing the excellent arc resistance. It is on offer.

In recent years, with the expansion of the field of demand for laminates used in the field of electronic and electrical equipment, demands for arc resistance, heat resistance, electrical properties, punching workability, and flame retardancy have increased significantly.

In view of this point, studies were conducted to effectively utilize the arc resistance and flame retardance, which are the original characteristics of the triazine-based amino resin-modified phenolic resin, to achieve the objective. By the way, the triazine-based amino resin-modified phenolic resin by itself cannot provide a laminate that maintains the required flame retardancy (for example, UL-94V-O). Furthermore, it has drawbacks such as low mechanical strength, brittleness, and cracking during punching. Conventionally, the use of organic halogen compounds has been known as a means of improving such drawbacks and providing desired flame retardancy.

For example, (1) halogenated phenols as flame retardants;
For example, a method of manufacturing a laminate by impregnating a paper base material with a resin composition in which tetrabromobisphenol A is added to a triazine-based amino resin-modified phenol resin, such as a melamine-modified phenol resin.

In this case, tetrabromobisphenol A is inexpensive, has a high bromine content, and exhibits an excellent flame retardant effect with a relatively small amount of J added, but due to the interaction between the phenolic OH group in the molecule and the halogen, the There is a risk of blistering and discoloration of the laminate, making it impossible to obtain the required electrical properties.

Further, there is a drawback that sufficient punching workability cannot be obtained even at high punching temperatures (for example, cracks occur around the holes even at 100° C.). (2) A method of manufacturing a laminate by impregnating a base material with a resin composition in which a flame-retardant epoxy resin, such as diglycidyl ether of tetrapromobisphenol A, is contained in the triazine-based amino resin-modified phenolic resin.

In this case, the resin composition used has excellent reactivity of two or more epoxy groups present in the molecule, which significantly increases mechanical strength and improves heat resistance, which is a drawback of triazine-based amino resin-modified phenolic resins. becomes very hard,
It is difficult to strike a balance between the required flame retardancy (for example, UL-94V-0) and punching workability (for example, no cracking at 80 to 120°C).

An even bigger drawback is that the prepreg obtained by impregnating a cellulose base material with a mixture of a halogenated epoxy resin and a triazine-based amino resin-modified phenol resin has poor storage stability because the reaction between the epoxy group and the amino group proceeds in the prepreg state. The present invention improves these drawbacks and provides a laminate that can provide the desired laminate without impairing the properties of the triazine-based amino resin-modified phenolic resin. A flame retardant resin composition is provided.

That is, in the present invention, after reacting a halogenated epoxy resin having at least two epoxy groups in the molecule with a halogenated phenol in a stoichiometrically equivalent amount to the resin,
Furthermore, a resin composition obtained by adding 10 to 50% by weight of a monoglycidyl ether represented by the general formula R:H or CH3, C4H, X:Br or Cln to the above reactant and reacting it. This is a flame-retardant resin Z composition for laminates obtained by adding 20 to 50% by weight of resin solids to a triazine-based amino resin-modified phenolic resin.

The present invention basically consists of a triazine-based amino resin-modified phenolic resin, a halogenated phenol that is inexpensive as a flame retardant agent, has a high halogen content, and has an excellent flame retardant effect, and a laminate that has excellent heat resistance and electrical properties. By reacting with a halogenated epoxy resin that has at least two epoxy groups in the molecule that can give It improves sex.

However, even if the blending ratio of the halogenated phenols and halogenated epoxy resin is changed, the addition of the reactants of both to the triazine-based amino resin-modified phenolic resin
Even if the addition ratio is changed, it is difficult to maintain the required balance between flame retardancy, heat resistance, electrical properties, punching workability, and storage stability of the prepreg. However, a resin composition obtained by blending a monofunctional monoglycidyl ether represented by the above general formula with the reaction product of the halogenated phenol and the halogenated epoxy resin and allowing it to participate in the reaction can be used as a triazine-based resin composition. By incorporating it into an amino resin-modified phenolic resin, it is possible for the first time to achieve the desired balance of flame retardancy, heat resistance, electrical properties, punching processability, and storage stability of prepregs. This is due to the reaction between the halogenated phenols and the halogenated epoxy resin, the 0H group (ring opening of the engineered poxy group) generated by the reaction, and the terminal phenolic
This is thought to be due to the reaction between the H group and the monoglycidyl ether represented by the above general formula, which reduces the epoxy group that easily reacts with the amine compound in the triazine-based amino resin-modified phenolic resin. It is presumed that this not only extends the shelf life of the material, but also improves the punching processability when it is made into a laminate.

In carrying out the present invention, examples of halogenated epoxy resins having at least two epoxy groups in the molecule include diglycidyl ether of tetrapromobisphenol A, dibromoneopentyl glycol diglycidyl ether, etc. Examples of the phenols include tetrapromobisphenol A, tripromobisphenol A, tripromophenol, and dipromophenol, and preferably those having two phenolic OH groups are preferred from the viewpoint of heat resistance.

In the reaction between the halogenated epoxy resin and the halogenated funinols, it is preferable to react the same equivalent amount using a tertiary amine as a catalyst.

If the amount of halogenated phenols is less than the equivalent, the storage stability of the prepreg will not be sufficient, and in order to obtain the desired flame retardancy, it will be necessary to use a large amount of reactants, including an expensive halogenated epoxy resin, resulting in high costs. become.

On the other hand, if the amount of halogenated phenols exceeds the equivalent amount, heat resistance becomes a problem. Monoglycidyl ethers represented by the above general formula include dipromocresyl monoglycidyl ether, dipromophenyl monoglycidyl ether, dipromobutylphenyl monoglycidyl ether, ditalolocresyl monoglycidyl ether, dichlorobutylphenyl monoglycidyl ether, etc. can be used.

The amount of monoglycidyl ether added is preferably within the range of 10 to 50% by weight based on the reaction product of the halogenated epoxy resin and halogenated phenol, and if it is less than 10% by weight, the storage stability of the prepreg will not improve. This is not sufficient, and the punching workability necessary for practical use as a laminate cannot be obtained. On the other hand, if it exceeds 50% by weight, the heat resistance and electrical properties of the laminate will deteriorate. Further, the monoglycidyl ether is preferably added at a time when the reaction between the halogenated epoxy resin and the halogenated phenols reaches equilibrium. Triazine-based amino resin-modified phenolic resins include those obtained by co-condensing amines such as melamine, methylguanamine, and benzoguanamine in the process of producing phenolic resins, or those obtained by co-condensing amines such as melamine, methylguanamine, benzoguanamine, etc., or by converting an initial condensate of the above amines and formaldehyde into phenol-formaldehyde resin. Obtained by addition or reaction.

The amount of the resin composition prepared by reacting the halogenated epoxy resin, halogenated phenol, and monoglycidyl ether added to the triazine-based amino resin-modified phenolic resin can be increased or decreased depending on the flame retardance required. However, in order to have heat resistance, electrical properties, and practically necessary punching workability, which are the objectives of the present invention, it is desirable that the amount is 20 to 50% by weight, and 20 to 50% by weight based on the modified phenolic resin.
If less than % by weight, the required flame retardancy (UL-94-V-1),
Punching workability is not sufficient, and if it exceeds 50% by weight, heat resistance is reduced. The present invention will be explained in more detail below using Examples.

Example 1 Tetrapromobisphenol A, a bisphenol A type epoxy resin compound having epoxy groups at both ends of the molecule
400 parts by weight of diglycidyl ether, 272 parts by weight of tetrapromobisphenol A and toluene were added to make a 60% solution by weight, then 1 part by weight of benzyldimethylamine was added to this solution and the mixture was heated at 100°C for 4 hours. Made it react.

Furthermore, dibromocresyl monoglycidyl ether 200
Mix parts by weight and react at 100°C for 2 hours (the concentration of epoxy groups in the system is in equilibrium).Toluene is added to reduce the non-volatile content to 60%.
% by weight of varnish (4) was obtained. On the other hand, a triazine-based amino resin-modified phenolic resin was prepared as follows.

500 parts by weight of nonylphenol and 85% paraform 3
00 parts by weight of 10% paratoluenesulfonic acid solution
After adding parts by weight and reacting at 100°C for 3 hours, 30 parts of phenol was added.
0 parts by weight, 15 parts by weight of 25% aqueous ammonia were added, further 200 parts by weight of melamine-formaldehyde initial condensate were added, the reaction was allowed to proceed at 100°C for 1 hour, and then, after dehydration, methanol was added to reduce the non-volatile content to 60% by weight, resulting in gelation. A triazine-based amino resin-modified phenol varnish (B) was prepared for 5 minutes. Varnish (A) was mixed with triazine-based amino resin-modified phenolic resin varnish (B) prepared in this manner.
) was blended so as to have a solid content of 40% by weight, and this varnish was impregnated into 10 mils thick kraft paper and dried to obtain a prepreg with a resin content of 50% by weight.

9 sheets of this prepreg are stacked to give a weight of 100kg/CIn2.1
Laminate molding was performed at 60° C. for 50 minutes to obtain a laminate plate with a thickness of 1.6 m/m. Example 2 320 parts by weight of dipromoneopentyl glycol diglycidylnoether, 27 parts by weight of tetrapromobisphenol A
After adding 2 parts by weight and toluene to make a 60% solution by weight, 1.3 parts by weight of benzyldimethylamine was added and the solution was heated to 100°C.
The reaction was carried out for 5 hours.

Furthermore, 20% of dibromocresyl monoglycidyl ether
The mixture was mixed with 7 parts by weight and reacted at 100°C for 2 hours, and toluene was added to obtain a varnish (C) with a nonvolatile content of 60% by weight. Varnish (C) was added at 3% to the varnish (B) prepared in Example 1.
It was blended so that it was 0% by weight. Next, a laminate with a thickness of 1.6 m/m was obtained in the same manner as in Example 1. Comparison example
1 Tetrapromobisphenol A was added to the varnish (B) prepared in Example 1 in an amount of 25% by weight in terms of solid content, and a laminate with a thickness of 1.6 m/m was obtained in the same manner as in Example 1.

Comparative Example 2 30% by weight of diglycidyl ether of tetrapromobisphenol A was added to the varnish (B) prepared in Example 1 in terms of solid content, and then 1.
A laminate with a thickness of 6 m/m was obtained.

Note that the laminate manufactured in this comparative example was laminated and molded immediately after preparing the prepreg. The above examples,
A characteristic test was conducted on the laminate obtained in the comparative example, and the results shown in Table 1 were obtained.

It also shows the shelf life of the prepreg. As is clear from the results in Table 1, the laminate obtained by impregnating and molding a base material with the varnish of the resin composition of the present invention maintains the required flame retardancy (UL-94V-0), It has sufficient heat resistance, punching workability, electrical insulation properties, and arc resistance.

In particular, the present invention takes advantage of the characteristics of triazine-based amino resin-modified phenolic resin, improves the low mechanical strength, and improves the storage stability of prepreg when used in combination with flame-retardant epoxy resin. It is a relatively low cost and highly practical flame retardant that does not require the use of other additive flame retardant plasticizers (e.g. organic phosphate esters) that may reduce heat resistance or mechanical strength. Laminated plates can be provided.

Claims (1)

[Claims] 1. A reactant of a halogenated epoxy resin having at least two epoxy groups in the molecule and an equivalent amount of halogenated phenol further includes a general formula ▲ mathematical formula, chemical formula, table, etc. ▼ R: H or CH_3, C_4H_9 A flame-retardant resin composition for a laminate, which contains 20 to 50% by weight of solid resin based on the resin.