JP4568937B2 - Flame retardant resin composition, prepreg and laminate using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition, a prepreg and a laminate having excellent flame retardancy without using a halogen-based flame retardant.
[0002]
Thermosetting resins typified by epoxy resins and the like are widely used for electrical and electronic equipment parts due to their excellent characteristics, and are often provided with flame retardancy in order to ensure safety against fire. Conventionally, flame retardants of these resins have been made using halogen-containing compounds such as brominated epoxy resins. Although these halogen-containing compounds have a high degree of flame retardancy, aromatic bromine compounds not only separate corrosive bromine and hydrogen bromide by thermal decomposition, but also are highly toxic when decomposed in the presence of oxygen. May form bromodibenzofuran and polydibromobenzoxine.
Also, it is extremely difficult to dispose of obsolete waste containing bromine. For these reasons, phosphorus compounds, nitrogen compounds, and inorganic fillers have been studied as flame retardants to replace bromine-containing flame retardants.
[0003]
As described above, flame retardancy can be realized by a phosphorus compound, a nitrogen compound, and an inorganic filler. The mechanism is that nitrogen compounds and phosphorus compounds promote carbonization of the resin and prevent combustion, and inorganic fillers can be added to the resin to reduce flammable resin, resulting in difficulty in burning. It is. Also, inorganic fillers such as metal hydroxides prevent combustion by releasing water during combustion and lowering the temperature. It is a well-known fact that a resin is flame-retarded with a phosphorus compound, a nitrogen compound and an inorganic filler without using a halogen compound, as seen in JP-A-10-195178 and JP-A-10-166501. In addition, prepregs and laminates using these resin compositions have been put into practical use.
[0004]
In the laminated plate manufacturing process, various chemical processes are performed, in the desmear process, a basic compound such as sodium hydroxide is used, and in the blackening process, an oxidized compound is used. In general, phosphorus compounds such as phosphoric acid esters and inorganic fillers used as flame retardants have the disadvantage of reacting with these compounds and causing defects.
[0005]
[Problems to be solved by the invention]
The present invention has been made as a result of studies to solve such problems, and has excellent chemical resistance and flame resistance by using a phosphine oxide compound having high hydrolysis resistance as a phosphorus-based flame retardant. The present invention provides a resin composition having the above characteristics, a prepreg, and a flame retardant laminate obtained from the prepreg.
[0006]
[Means for Solving the Problems]
The present invention is a flame retardant resin composition for laminates, comprising (A) a phenol novolac epoxy resin, (B) dicyandiamide, and (C) triphenylphosphine oxide as essential components . And it is the prepreg characterized by making a base material impregnate the flame-retardant resin composition for laminated boards of this invention, and also the said prepreg is piled up 1 sheet or 2 sheets or more, and heat-pressed. copper-clad laminate characterized by comprising.
[0007]
As described above, inorganic fillers are useful as flame retardants for epoxy resins or epoxy resin laminates, but many have poor chemical resistance against basic compounds and oxidized compounds. In addition, additive-type phosphate esters such as triphenyl phosphate and cresyl diphenyl phosphate, which are generally used as phosphorus flame retardants, are easily hydrolyzed and easily eluted in a chemical solution. For this reason, the resin composition which uses these compounds as a flame retardant has a problem in using for a laminated board.
[0008]
Phosphine oxides have a P—C bond and are not easily hydrolyzed. For this reason, it is excellent in chemical resistance unlike phosphate esters having a P—O bond. In general, since the phosphorus content is high, the addition of a small amount has sufficient flame retardancy, and there is no need to use an inorganic filler.
The resin composition of the present invention uses a phosphine oxide compound having strong hydrolysis resistance as a phosphorus flame retardant, and exhibits sufficient flame resistance and chemical resistance without using a halogen compound. It is the technical outline and has sufficient flame retardancy without using inorganic fillers.
[0009]
As the epoxy resin of component (A) used in the present invention, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A novolak type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, tetrakis (glycidyloxyphenyl) ) Ethane and the like are mentioned, but the ethane is not limited to these, and several types may be used simultaneously. In view of heat resistance, novolak type epoxy resins such as bisphenol A novolak type epoxy resin, phenol novolak type epoxy resin, and cresol novolak type epoxy resin are preferable.
[0010]
Examples of the curing agent for the component (B) used in the present invention include novolak resins, dicyandiamide, amine compounds, and acid anhydrides. A novolac resin or dicyandiamide is preferable because of its high heat resistance. Further, it is preferable to use triazine novolac as the novolak resin because the flame retardancy is improved by the effect of the nitrogen component.
[0011]
As the phosphine oxide of component (C) used in the present invention, triphenylphosphine oxide, tricresylphosphine oxide, trioctylphosphine oxide, octyl (phenyl) -N, N′-diisobutylcarbamoylmethylphosphine oxide, tris- (4 -Aminophenyl) phosphine oxide and the like, but are not limited thereto. Considering versatility, triphenylphosphine oxide is preferable. Tris- (4-aminophenyl) phosphine oxide is preferable because it can react with an epoxy resin to introduce a flame retardant into the resin skeleton and heat resistance is increased.
[0012]
The flame-retardant resin composition of the present invention contains the above-described epoxy resin, curing agent, and phosphine oxide as essential components. However, other resins, curing accelerators, and coupling agents are used as long as they do not contradict the purpose of the present invention. It is possible to add other components. However, in the present invention, it is preferable not to add an inorganic filler and / or phosphate ester in order not to deteriorate the properties as a resin and a laminate, particularly chemical resistance, and excellent difficulty even without the addition. It exhibits flammability.
[0013]
The flame-retardant resin composition of the present invention is used in various forms. When impregnating a base material, it is usually used in the form of a varnish dissolved in a solvent. Although it is desirable that the solvent used has good solubility in the composition, a poor solvent may be used as long as it does not adversely affect the composition.
[0014]
A varnish obtained by dissolving the flame-retardant resin composition of the present invention in a solvent is coated and impregnated on a substrate such as a glass fabric, a glass fabric, or a fabric or fabric containing other than glass as a component. A prepreg can be obtained by drying at 200 ° C. Such a prepreg is used for producing a laminate or a copper clad laminate by heating and pressing. The flame retardant resin composition of the present invention is a thermosetting resin composition having a high degree of flame retardancy without containing a halogen compound, and is particularly suitable for use in laminated boards for printed wiring boards. It is.
[0015]
【Example】
Hereinafter, the present invention will be specifically described by way of examples.
[0016]
( Reference Example 1 )
Cresol novolac epoxy resin (Epiclon N-690, manufactured by Dainippon Ink & Chemicals, Inc.), phenol aralkyl resin (Mirex XLC-LL, manufactured by Mitsui Chemicals, Inc.) 52 parts by weight, triazine-modified phenol novolac resin (Dainippon) Methyl Cellosolve was added to 15 parts by weight of LA-7054 (Ink Chemical Industry Co., Ltd.) and 38 parts by weight of triphenylphosphine oxide, and a varnish was prepared so as to have a nonvolatile content concentration of 60% by weight. At this time, the phosphorus component was 2.1% by weight and the nitrogen component was 0.9% by weight with respect to the total of 100% by weight of the epoxy resin, the phosphorus compound and the curing agent. Using this varnish, 100 parts by weight of glass fiber cloth (thickness 0.18 mm, manufactured by Nitto Boseki Co., Ltd.) was impregnated with 80 parts by weight of varnish solids, and dried in a dryer oven at 150 ° C. for 5 minutes to obtain a resin. A prepreg having a content of 44.4% was produced. Six prepregs are stacked, and 35 μm thick electrolytic copper foil is stacked on the top and bottom, and the pressure is 40 kgf / cm 2 and the temperature is 190 ° C. and 120 ° C.
Minute heating and pressure molding was performed to obtain a double-sided copper-clad laminate having a thickness of 1.2 mm.
[0017]
(Example 2)
Dimethylformamide is added to 100 parts by weight of a phenol novolac type epoxy resin (Epiclon N-770, manufactured by Dainippon Ink and Chemicals, Inc.), 5.5 parts by weight of dicyandiamide, and 23 parts by weight of triphenylphosphine oxide, and the nonvolatile content concentration is 60% by weight. A varnish was prepared so that At this time, the phosphorus component was 2.0% by weight and the nitrogen component was 2.9% by weight with respect to the total of 100% by weight of the epoxy resin, the phosphorus compound and the curing agent.
Using this varnish, 100 parts by weight of glass fiber cloth (thickness 0.18 mm, manufactured by Nitto Boseki Co., Ltd.) was impregnated with 80 parts by weight of varnish solid, and dried in a dryer oven at 150 ° C. for 5 minutes to obtain a resin. A prepreg having a content of 44.4% was produced.
6 sheets of the above prepregs, 35 μm thick electrolytic copper foils are stacked on the top and bottom, and heat-pressed for 120 minutes at a pressure of 40 kgf / cm ² and a temperature of 190 ° C., and a 1.2 mm thick double-sided copper-clad laminate Got.
[0018]
(Example 3 , Reference Example 4 , and Comparative Examples 1-3)
A double-sided copper-clad laminate was prepared in the same manner as in Example 1 and Example 2 except for the formulation shown in Table 1.
[0019]
About the obtained copper clad laminated board, the flame retardance, solder heat resistance, and peel strength were measured. The evaluation results are shown in Tables 1 and 2. The copper clad laminates shown in the examples are all excellent in flame resistance and chemical resistance.
[0020]
[Table 1]
[0021]
[Table 2]
[0022]
(Measuring method)
1. . Flame retardancy: Evaluated by vertical method according to UL-94 standard.
2. . Solder heat resistance, peel strength: measured in accordance with JISC6481.
3. Solder heat resistance: After performing a moisture absorption treatment for 2 hours after boiling, the presence or absence of abnormal appearance was observed after being immersed in a solder bath at 260 ° C. for 120 seconds.
4). Chemical resistance: The weight loss rate when immersed in a 20% aqueous solution of sodium hydroxide at 80 ° C. for 10 minutes and the weight decrease rate when immersed in a 20% aqueous solution of potassium persulfate at 70 ° C. for 96 hours were determined.
[0023]
Notes to Table (1) Daikoku Ink Chemical Industries, Ltd. Epicron N-690, Epoxy Equivalent = 210
(2) manufactured by Dainippon Ink & Chemicals, Inc. Epicron N-770, epoxy equivalent = 190
(3) Mitsui Chemicals Co., Ltd. Millex XLC-LL, hydroxyl group equivalent = 175
(4) Dainippon Ink & Chemicals, Inc. LA-7054, hydroxyl equivalent = 125, nitrogen content = 12% by weight
(5) Weight reduction rate when immersed in a 20% by weight aqueous solution of sodium hydroxide at 80 ° C. for 10 minutes (6) Weight reduction rate when immersed in a 20% by weight aqueous solution of potassium persulfate at 70 ° C. for 96 hours
【The invention's effect】
The flame retardant resin composition of the present invention, a prepreg and a laminate using the same, have high flame retardancy without adding a halogen compound, have excellent properties such as solder heat resistance, and sufficient Has chemical resistance. Accordingly, the present invention provides a novel and useful thermosetting resin composition as a non-halogen material required in the future.

Claims (3)

A flame retardant resin composition for a laminate comprising (A) a phenol novolac epoxy resin, (B) dicyandiamide, and (C) triphenylphosphine oxide as essential components .   A prepreg obtained by impregnating a base material with the flame retardant resin composition for laminates according to claim 1. CCL characterized by comprising heating and pressing superposed claim 2 prepreg according to one or two or more.