JP2000239491A - Flame-retardant resin composition, and prepreg and laminate made by using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition having high flame retardancy without adding a halogen compound thereto, and a laminate made by using the composition. SOLUTION: The flame-retardant resin composition comprises essentially (A) a non-halogenated epoxy resin, (B) a curing agent comprising a triazine- modified phenolic novolak resin, and (C) 9,10-dihydro-9-oxa-10-(2,5- dioxotetrahydro-3-furanylmethyl)-10-phosphaphenanthrene-10-oxide represented by the formula. A prepreg is made by impregnating a base material with the resin composition. The laminate or copper-clad laminate is obtained by heating and pressing one or more plies of the prepreg put together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition which has excellent flame retardancy without using a halogen-based flame retardant and can be used for a long period of time, a prepreg and a laminate using the same. It is about a board.

[0002]

2. Description of the Related Art Thermosetting resins typified by epoxy resins are widely used for electric and electronic equipment parts due to their excellent properties, and are provided with flame retardancy to ensure fire safety. There are many cases. Conventionally, these resins have generally used a halogen-containing compound such as a brominated epoxy resin. Although these halogen-containing compounds have high flame retardancy, aromatic bromine compounds not only separate corrosive bromine and hydrogen bromide by pyrolysis,
May degrade in the presence of oxygen to form highly toxic polybromodibenzofuran and polydibromobenzooxin. Further, it is extremely difficult to treat aging waste materials and refuse containing bromine. For these reasons, phosphorus compounds have been studied as flame retardants in place of bromine-containing flame retardants.

[0003] As described above, flame retardancy can be realized by a phosphorus compound and a nitrogen compound. The mechanism is that the nitrogen compound promotes the decomposition of the phosphorus compound and the production of polyphosphoric acid by thermal condensation, and the polyphosphoric acid forms a film on the surface of the epoxy resin, which has an insulating effect and an oxygen blocking effect, and as a result, combustion It is to prevent. Phosphoric acid esters such as triphenyl phosphate and cresyl diphenyl phosphate have been used as phosphorus compounds used for flame retardation, but when these are added to epoxy resins and the like, the plasticity of these compounds is reduced. As a result, there is a disadvantage that the glass transition point of the resin is significantly reduced. These phosphates do not form a covalent bond with the skeleton of the epoxy resin, and the interaction between the phosphorus compounds is greater than the interaction between the phosphorus compound and the resin skeleton.
Therefore, when a prepreg is prepared by adding these phosphate esters to a resin, there arises a problem that the phosphate esters easily crystallize after a lapse of time and are deposited on the surface of the prepreg, so that it cannot be used.

Therefore, if the phosphorus compound can be incorporated into the epoxy resin skeleton by a covalent bond, it is considered that problems such as a drastic decrease in the glass transition point of the resin and precipitation of the phosphorus compound on the prepreg surface can be solved. As a method of incorporating a phosphorus compound into an epoxy resin skeleton by a covalent bond,
Journal of Applied Polymer Science, Vol. 61, p1781-17
96 (1996), etc., but these methods have the drawback of having a large cost for synthesis.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve such a problem, and has been reported as a flame retardant for 9,10-dihydro-9-oxa-10-.
By using (2,5-dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10-oxide, the properties of the resin composition and the prepreg do not change over a long period of time, and a nitrogen compound is used in combination. The purpose of the present invention is to provide a resin composition having a high flame retardancy, a prepreg, and a laminate obtained from the prepreg, with the object of expressing flame retardancy without using halogen due to the interaction between nitrogen and phosphorus. Is what you do.

[0006]

The present invention comprises (A) a non-halogenated epoxy resin, (B) a curing agent comprising a triazine-modified phenol novolak resin, and (C)
9,10-dihydro-9-oxa-10- (2,5-dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10- represented by the general formula (1)
A flame-retardant resin composition comprising an oxide as an essential component. A prepreg obtained by impregnating a base material with the flame-retardant resin composition, and further comprising heating and pressurizing one or more of the prepregs. It is a laminate or a copper-clad laminate.

[0007]

Embedded image

[0008] To solve the problems caused by the above-mentioned phosphate ester, 9,10-dihydro-9-oxa-10- (2,
5-dioxotetrahydro-3-furanylmethyl) -1
Since 0-phosphaphenanthrene-10-oxide reacts with an epoxy group, it can be easily incorporated into an epoxy resin skeleton. However, since it is an acid anhydride, it is difficult to use it together with amines, and it is difficult to incorporate a nitrogen-based flame-retardant component into the resin skeleton. Therefore, the triazine-modified phenol novolak resin has a phenolic hydroxyl group and has nitrogen, and thus is useful as a nitrogen-based flame retardant.

As described above, in the present invention, a non-halogenated epoxy resin is used as an epoxy resin, a triazine-modified phenol novolak resin is used as a curing agent, and a 9,10-dihydro-formula represented by the general formula (1) is further used. By using 9-oxa-10- (2,5-dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10-oxide in combination, a synergistic effect between nitrogen and phosphorus is developed, and a halogen-containing substance is used. Instead, a high degree of flame retardancy of the laminate is exhibited.

The component (A) used in the present invention includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, etc., but is not limited thereto. , Or several types may be used at the same time. Considering heat resistance, a cresol novolak type epoxy resin is desirable.

The component (B) used in the present invention is a curing agent comprising a triazine-modified phenol novolak resin.
For example, it is represented by the following general formula (2). This triazine-modified phenol novolak resin is blended as all or a part of a curing agent for the epoxy resin. The triazine-modified phenol novolak resin preferably has a nitrogen content of 8% by weight or more because the effect on flame retardancy is small if the nitrogen content is small.

[0012]

Embedded image m and n are natural numbers, and R is an alkyl group, an aryl group, or —NH ₂

As a part of the curing agent, those other than triazine-modified phenol novolak resin such as phenol novolak resin can be used. Phenol aralkyl resins or naphthalene aralkyl resins have the characteristics of low water absorption and high flame retardancy. Further, since the hydroxyl group equivalent is larger than that of the phenol novolak resin, curing shrinkage is small and the adhesion is excellent. For this reason, when phenol aralkyl resin and naphthalene aralkyl resin are used together,
And the properties of the laminate can be improved.

The flame-retardant resin composition of the present invention comprises the above-mentioned non-halogenated epoxy resin, a triazine-modified phenol novolak resin as a curing agent, and 9,10-dihydro-9-oxa-10- (2,5- Although it contains dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10-oxide as an essential component, other curing agents, curing accelerators, coupling agents, etc., within a range not inconsistent with the object of the present invention. May be added.

Although the flame-retardant resin composition of the present invention is used in various forms, a solvent is usually used to impregnate the base material. The solvent used must have good solubility for a part of the composition, but a poor solvent may be used as long as it does not adversely affect the composition.

The 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 glass woven fabric, glass non-woven paper, or a cloth containing a component other than glass. By drying at 200 to 200 ° C., a prepreg for a laminate can be obtained. Prepreg is used to produce a laminated board for printed wiring boards by heating and pressing, but since the flame-retardant resin composition of the present invention has high flame retardancy without adding a halogen compound, It is suitably used for the above-mentioned laminated board and the like.

[0017]

The present invention will be described below in more detail with reference to examples.

Example 1 Cresol novolak epoxy resin (Epiclon N-69 manufactured by Dainippon Ink and Chemicals, Inc.)
0: epoxy equivalent 210) 60 parts by weight, triazine-modified phenol novolak resin (LA-7052 manufactured by Dainippon Ink and Chemicals, Inc .: nitrogen content 8%) 19 parts by weight,
N, N'-dimethylformamide was added to 21 parts by weight of 9,10-dihydro-9-oxa-10- (2,5-dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10-oxide. The varnish was adjusted so as to have a nonvolatile content of 60%. At this time, the phosphorus component was 1.9 parts by weight based on 100 parts by weight of the epoxy resin, the phosphorus compound, and the curing agent in total. Using this varnish, 100 parts of glass cloth (0.18 mm thick, manufactured by Nitto Boseki) was impregnated with 80 parts of a varnish solid to obtain 1 part.
Dry in a dryer at 50 ° C for 5 minutes, resin content 44.4%
Prepreg was created. Six sheets of the above prepreg were stacked, and an electrolytic copper foil having a thickness of 35 μm was stacked on top and bottom, and the pressure was set
Heat and pressure molding was performed at kgf / cm ^{2 at} a temperature of 190 ° C. for 120 minutes to obtain a double-sided copper-clad laminate having a thickness of 1.2 mm.

Regarding the obtained laminate, the flame retardancy was UL
It was evaluated according to the -94 standard in the vertical direction. Solder heat resistance,
The peel strength was measured in accordance with JIS C 6481, and the solder heat resistance was examined for abnormal appearance after immersion in a solder bath at 260 ° C. for 120 seconds after performing a moisture absorption treatment for 2 hours after boiling. The prepreg obtained above was left for 30 days in an environment of 23 ° C., and the appearance of the prepreg was inspected. No abnormality was found and no change was observed. Table 1 shows the results.

(Examples 2 to 4 and Comparative Examples 1 to 3)
And the formulation shown in Table 2 except that
A double-sided copper-clad laminate was prepared in the same manner as described above. The evaluation results are shown in Tables 1 and 2. All of the laminates having the formulations shown in Examples have excellent flame resistance and solder heat resistance. In addition, the appearance was examined after leaving the prepreg at 30 ° C. for 30 days, and it was found that there was no abnormality and the prepreg was stable, and that no phosphorus crystals were precipitated.

[0021]

[Table 1]

[0022]

[Table 2]

Notes to Tables 1 and 2 1) Epicron N-690 manufactured by Dainippon Ink and Chemicals, Inc .: Epoxy equivalent 210 2) Epicron 830S manufactured by Dainippon Ink and Chemicals, Inc .: Epoxy equivalent 170 3) Millex XLC-LL 4 manufactured by Mitsui Chemicals, Inc. ) LA-7052, manufactured by Dainippon Ink and Chemicals, Inc .: nitrogen content 8% 5) LA-7054, manufactured by Dainippon Ink and Chemicals, Inc. 12% nitrogen content 6) After performing a moisture absorption treatment for 2 hours at boiling, soldering at 260 ° C. Appearance after immersion in tank for 20 seconds 7) Appearance of prepreg after storage at 23 ° C for 30 days 8) Sumitomo Durez PR-51470

[0024]

As is clear from the above examples, the flame-retardant resin composition of the present invention has high flame retardancy and solder heat resistance without adding a halogen compound, and will be required in the future. An object of the present invention is to provide a novel thermosetting resin composition as a non-halogen material.

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Claims (4)

[Claims] 1. A curing agent composed of (A) a non-halogenated epoxy resin, (B) a triazine-modified phenol novolak resin, and (C) 9,10-dihydro-9- represented by the general formula (1). A flame-retardant resin composition comprising oxa-10- (2,5-dioxotetrahydro-3-furanylmethyl) -10-phosphaphenanthrene-10-oxide as an essential component. Embedded image 2. The flame-retardant resin composition according to claim 1, which contains a novolak type epoxy resin as the epoxy resin of the component (A). 3. A prepreg comprising a base material impregnated with the flame-retardant resin composition according to claim 1 or 2. 4. A laminate or a copper-clad laminate, wherein one or more prepregs according to claim 3 are overlaid and heated and pressed.