JP2003072011A - Fire-retardant composite laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-retardant epoxy resin composition and an epoxy resin composite copper clad laminated sheet using the same and having tracking resistance. SOLUTION: In the composite laminated sheet constituted by combining and laminating prepregs, which are obtained by impregnating a glass fabric and a glass nonwoven fabric with an epoxy resin composition and drying the impregnated fabrics, to mold them under heating and pressure, an intermediate layer comprises the glass nonwoven fabric impregnated with the fire-retardant epoxy resin composition containing a novolac type epoxy resin (A), a triazine modified phenol novolac resin (B), a reactive phosphorus type fire retardant (C) and aluminum hydroxide (D) or the like as essential components in specific amounts. A surface layer comprises the glass fabric impregnated with an epoxy resin based on a non-brominated epoxy resin, containing no phosphorus or the like and containing aluminum hydroxyde or the like in a specific amount with respect to the resin of the surface layer.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking-resistant composite laminate having excellent flame retardancy without using a halogen-based flame retardant. 2. Description of the Related Art As consumer electronic equipment and industrial electronic equipment are becoming smaller and more sophisticated, transformers, transistors, and the like are used in circuit boards to which high voltages are applied, such as computers and measuring instruments. , An epoxy resin glass-clad laminate or an epoxy resin composite copper-clad laminate is often used in terms of strength. In addition to this, in order to increase the density, a substrate with excellent tracking resistance is required from the standpoint of ensuring safety, and therefore an epoxy resin composite copper-clad laminate with excellent cost performance and tracking resistance is required. The demand for boards is increasing. On the other hand, thermosetting resins typified by epoxy resins and the like are widely used in electrical and electronic equipment parts and the like because of their excellent properties, and are provided with flame retardancy to ensure fire safety. There are many cases. Conventionally, halogen-containing compounds such as brominated epoxy resins are generally used to make these resins flame-retardant. These halogen-containing compounds have a high degree of flame retardancy. It not only separates corrosive bromine and hydrogen bromide by decomposition, but also forms highly toxic polybromodibenzofuran and polydibromobenzooxin when decomposed in the presence of oxygen. Further, it is extremely difficult to treat aging waste materials and refuse containing bromine. For these reasons, phosphorus compounds have been widely studied as flame retardants in place of bromine-containing flame retardants. However, if a phosphorus compound is used alone in an epoxy resin system, it is necessary to add a large amount of the phosphorus compound in order to obtain sufficient flame retardancy, and mechanical, chemical, or electrical properties are significantly degraded. Occurs. [0004] The present invention has been made as a result of various studies to solve the above-mentioned problems, and comprises a triazine-modified phenol novolak resin, a reactive phosphorus-based flame retardant, and an inorganic filler. By using aluminum hydroxide or magnesium hydroxide in combination as an agent, a composite laminate having high flame retardancy and excellent tracking resistance can be provided without adding a halogen-containing compound. As described above, when only a phosphorus compound is used as a flame retardant in an epoxy resin laminate, it is necessary to add a large amount of the phosphorus compound in order to obtain sufficient flame retardancy. However, there is a disadvantage that the electrical characteristics are significantly reduced. In the present invention, in order to solve such a problem, the use of a novolak type epoxy resin having a highly flame-retardant skeleton as the epoxy resin reduces the amount of the phosphorus component, and achieves both flame retardancy and heat resistance. Is a technical framework. The present invention provides: (1) a glass woven fabric and a glass nonwoven fabric which are each impregnated with epoxy resin and dried, combined with prepregs, laminated and heated and pressed. In composite laminates,
The intermediate layer contains (A) a novolak epoxy resin, (B) a triazine-modified phenol novolak resin, (C) a reactive phosphorus-based flame retardant, and (D) an aluminum filler and / or magnesium hydroxide as an inorganic filler as essential components. ,
(A) Number of epoxy groups of novolak type epoxy resin and (B) OH of triazine-modified phenol novolak resin
The ratio of the number of groups is epoxy group / OH group = 0.8 to 1.4, and the content of the phosphorus component of the reactive phosphorus flame retardant (C) is (A), (B) and (C). 0.5 to 5 parts by weight with respect to 100 parts by weight in total, and (D) 100 to 250 parts by weight with respect to 100 parts by weight of the total amount of the components (A), (B) and (C). A glass nonwoven fabric impregnated with a flame-retardant epoxy resin composition in parts by weight, wherein the surface layer contains a non-brominated epoxy resin as a main component, does not contain phosphorus or a phosphorus compound, and has a resin 100 of the surface layer. A composite laminate, comprising a glass woven fabric impregnated with an epoxy resin containing 10 to 200 parts by weight of aluminum hydroxide and / or magnesium hydroxide based on part by weight. The novolak type epoxy resin (A) used in the present invention includes phenol type and bisphenol A
And cresol type, and these can be used alone or in combination of two or more. However, in order to obtain high flame retardancy, a phenol novolak type epoxy resin having a small amount of an aliphatic hydrocarbon portion, a cresol novolak Type epoxy resins are preferred. The component (B) used in the present invention is a curing agent comprising a triazine-modified phenol novolak 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. As a part of the curing agent, those other than triazine-modified phenol novolak resin such as phenol novolak resin and aromatic amine can be used. In particular, a phenol aralkyl resin or a naphthalene aralkyl resin is preferable because of its low water absorption and high flame retardancy. Further, since the hydroxyl equivalent is larger than that of the phenol novolak resin, curing shrinkage is small and the adhesive strength is excellent. For this reason, when a phenol aralkyl resin and a naphthalene aralkyl resin are used in combination, it is possible to improve the laminated board characteristics such as the adhesive strength and the heat resistance to moisture absorption solder. The ratio of the number of epoxy groups in the (A) novolak type epoxy resin to the number of OH groups in the (B) triazine-modified phenol novolak resin is epoxy group / OH group = 0.8 to
1.4, desirably 0.9 to 1.2. If it is less than 0.8, the cured product is hard and brittle, and the punching workability of a laminated plate is poor. If it exceeds 1.4, heat resistance and glass transition temperature (Tg) are undesirably reduced. The reactive phosphorus flame retardant (C) used in the present invention includes 9,10-dihydro-9-oxa-1.
0-phosphaphenanthrene-10-oxide, resorcil diphenyl phosphate, phenylphosphonic acid, diphenylphosphonic acid and the like can be mentioned. Considering the effect on flame retardancy, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is preferred. The (C) reactive phosphorus flame retardant is used as a phosphorus component in a total of 100 parts by weight of (A) a novolak epoxy resin, (B) a triazine-modified phenol novolak resin, and (C) a reactive phosphorus flame retardant. On the other hand, it is 0.5 to 5 parts by weight. If the amount is less than 0.5 part by weight, the effect on flame retardancy is small, and if it exceeds 5 parts by weight, heat resistance is lowered, which is not preferable. The inorganic filler of the component (D) is (A)
It is preferable to contain 100 to 250 parts by weight based on 100 parts by weight of the total of novolak type epoxy resin, (B) triazine modified phenol novolak resin, and (C) reactive phosphorus flame retardant. If the amount is less than 100 parts by weight, the effect of improving the flame retardancy is small, and the coefficient of linear expansion of the laminate tends to increase. It is difficult to add more than 250 parts by weight because the viscosity of the resin is so high that uniform dispersion in the resin becomes difficult and impregnating property to the glass nonwoven fabric is reduced. Also, 20
When the amount is more than 0 parts by weight, the heat resistance can be further improved while maintaining high flame resistance by using aluminum hydroxide and magnesium hydroxide in combination. The above (A), (B), (C) and (D)
A prepreg is obtained by impregnating a glass nonwoven fabric with the flame-retardant epoxy resin composition comprising the components. Further, a predetermined number of the prepregs, an epoxy resin impregnated glass woven fabric prepreg for the surface layer, and a copper foil are laminated as required, and the resulting laminate is formed by heating and pressing. The epoxy resin composition of the surface layer contains a non-brominated epoxy resin as a main component, does not contain phosphorus or a phosphorus compound, and contains water as an inorganic filler with respect to a total of 100 parts by weight of the epoxy resin and the curing agent. A glass woven fabric impregnated with an epoxy resin composition containing 10 to 200 parts by weight of aluminum oxide and / or magnesium hydroxide is used. If the content is less than 10 parts by weight, the effect on tracking resistance is low, and if it exceeds 200 parts by weight, the resin viscosity becomes too high, and it becomes difficult to impregnate the glass woven fabric. However, in this case, the flame retardancy of the surface layer may not be sufficient. For this reason, when the volume ratio of the surface layer is larger than 40% in a thin laminate having a thickness of 1 mm or less,
If the blending amount of the inorganic filler is less than 50 parts by weight, the flame retardancy is insufficient. Therefore, an epoxy resin composition containing 50 to 200 parts by weight is used. In the epoxy resin of the surface layer, since the brominated epoxy resin is very easily carbonized, the tracking resistance is poor, and it is essential to use a non-brominated epoxy resin. Further, the content of aluminum hydroxide and / or magnesium hydroxide is preferably 20 to 150 parts by weight based on 100 parts by weight of the total of the epoxy resin and the curing agent. When the volume ratio is larger than 40%, 50 to 150 parts by weight is preferable. Within this range, it has excellent tracking resistance and flame retardancy, and also has good impregnation into glass woven fabric, so that other properties such as electrical properties and mechanical properties are also good. In order to impart tracking resistance, inorganic fillers such as silica, talc, mica, and clay can be blended in addition to aluminum hydroxide and magnesium hydroxide. Aluminum oxide,
Magnesium hydroxide is preferred. The reason that the inorganic filler compounded in the epoxy resin of the surface layer improves the tracking resistance is thought to be due to the presence of the inorganic filler on the surface of the formed laminate, thereby reducing the proportion of the resin on the surface. Can be Aluminum hydroxide (alumina hydrate) is particularly preferred as the inorganic filler because aluminum hydroxide is decomposed by the heat of discharge to generate water, and water reacts with the organic matter decomposed by the discharge. It is considered that the formation of a track is prevented by generating a volatile substance. Further, when phosphorus or a phosphorus compound is added to the surface layer in order to improve the flame retardancy, the peeling strength of the copper foil may be reduced, which may hinder the repair work of the electronic component or may cause a problem in mounting the electronic component. There may be problems such as a decrease in the reliability of the used electronic components. For this reason, in the present invention, the surface layer does not contain phosphorus or a phosphorus compound, and the flame resistance of the intermediate layer is enhanced. Although the flame-retardant epoxy resin composition of the present invention is used in various forms, a solvent is usually used when impregnating a fiber base material to obtain a laminate. The solvent used must have good solubility in a part of the composition, but a poor solvent may be used as long as it does not adversely affect the solvent. The present invention will be described below in more detail with reference to examples. Parts are parts by weight. Example 1 After dissolving 0.5 part of 2-phenyl-4-methylimidazole in 120 parts of acetone, a phenol novolak type epoxy resin (Epiclon N-77 manufactured by Dainippon Ink and Chemicals, Inc.) was used.
0, Ep equivalent 190), 100 parts, triazine-modified phenol novolak resin (LA manufactured by Dainippon Ink and Chemicals, Inc.)
-7054) 63 parts by weight, and 9,10-dihydro-9
43 parts by weight of -oxa-10-phosphaphenanthrene-10-oxide (HCA manufactured by Sanko Co., Ltd.) was dissolved. Further, 160 parts of aluminum hydroxide and 160 parts of magnesium hydroxide were added, and the mixture was stirred and dispersed to prepare Varnish A. Using this varnish A, a glass nonwoven fabric (thickness 0.4
mm, manufactured by Japan Vilene Co., Ltd.), 100 parts of a varnish solid were impregnated with 700 parts, and dried with a drying drum at 150 ° C. for 5 minutes to prepare a glass nonwoven prepreg. Next, 30 parts of acetone and methyl cellosolve 2
In 0 parts of the mixed solution, 0.15 parts of 2-phenyl-4-methylimidazole and 4 parts of dicyandiamide are dissolved, and then 100 parts of a non-brominated bisphenol A type epoxy resin (Ep-850 manufactured by Yuka Shell) is dissolved. did. Further, 50 parts by weight of aluminum hydroxide was added and stirred and dispersed to prepare Varnish B. This varnish B is woven with a glass woven cloth (thickness 0.1).
8 mm, manufactured by Nitto Boseki) 100 parts by weight of varnish solid content
The resultant was impregnated with 00 parts by weight, and dried with a drying drum at 150 ° C. for 5 minutes to prepare a glass woven prepreg. One glass woven prepreg is placed on top and bottom of three glass nonwoven prepregs, and a thickness of 18 μm is placed on top and bottom.
m of electrolytic copper foil was stacked and heated and pressed at a pressure of 2 MPa and a temperature of 170 ° C. for 120 minutes to obtain a 1.6 mm-thick double-sided copper-clad laminate. Example 2 and Comparative Examples 1 to 8 Double-sided copper-clad laminates were prepared in the same manner as in Example 1 except that the formulation was as shown in Table 1. Table 1 shows the evaluation results.
See below. All of the laminates obtained in the examples have excellent flame resistance and solder heat resistance, good tracking resistance, and good copper foil peeling strength. [Table 1] The method for measuring the properties of the obtained laminate is as follows. 1. Tracking resistance: 0.1% after etching copper foil
The applied voltage when no short circuit occurred even when 50 or more drops of the ammonium chloride aqueous solution was dropped was determined. 2. Solder heat resistance: Measured according to JIS C 6481,
After performing the moisture absorption treatment for 2 hours after boiling, it was examined whether there was any abnormality in the appearance after floating for 180 seconds in a solder bath at 260 ° C. ：: No abnormality, ×: Swelling occurred 3. Copper foil peeling strength: measured according to JIS C6481. Flame retardancy: Evaluated by the vertical method according to UL-94 standard. The flame-retardant resin composition of the present invention has high flame retardancy without adding a halogen-containing compound, has excellent solder heat resistance, and will be required in the future. It is useful for laminates that do not use halogen-containing materials. Also,
When this flame-retardant resin composition is used, even if a resin composition containing no phosphorus or a phosphorus compound containing a non-brominated epoxy resin as a main component is used for the surface layer, the flame retardancy is excellent, so that the tracking resistance is improved. And a halogen-free epoxy resin composite copper-clad laminate having excellent copper foil peeling strength.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08G 59/62 C08G 59/62 C08K 3/22 C08K 3/22 5/49 5/49 C08L 63/00 C08L 63/00 CF term (reference) 4F100 AA18B AA18C AA19B AA19C AB17D AB17E AB33D AB33E AG00A AG00B AG00C AK33B AK53A AK53B AK53C AL05B AL06B BA03 BA05 BA07 BA10A BA10C BA10D BA10A DG12CA23B02A DG12C02A EW046 EW066 EW126 FD01 FD136 GF00 4J036 AA02 AF06 AF07 DC10 DC45 FA02 FA04 FB07 FB08 JA08

Claims (1)

Claims: 1. A composite laminate obtained by impregnating a glass woven fabric and a glass nonwoven fabric with an epoxy resin and then drying and drying prepregs, laminating them, and press-molding the same. , (A) novolak type epoxy resin,
(B) a curing agent composed of a triazine-modified phenol novolak resin; (C) a reactive phosphorus-based flame retardant; and (D) aluminum hydroxide and / or magnesium hydroxide as an inorganic filler as essential components, and (A) a novolak epoxy resin. The ratio of the number of epoxy groups to the number of OH groups of the (B) triazine-modified phenol novolak resin is such that epoxy group / OH group = 0.
8 to 1.4, and the content of the phosphorus component of the reactive phosphorus flame retardant (C) is 10 in total of the components (A), (B) and (C).
0 to 5 parts by weight, and 0.5 to 5 parts by weight, and (D) the inorganic filler is 100 to 250 parts by weight based on 100 parts by weight of the total amount of the components (A), (B) and (C). Part of the glass nonwoven fabric impregnated with the flame-retardant epoxy resin composition, the surface layer is mainly composed of a non-brominated epoxy resin, does not contain phosphorus or phosphorus compounds, and 100% by weight of the resin of the surface layer A composite laminate comprising a glass woven fabric impregnated with an epoxy resin containing 10 to 200 parts by weight of aluminum hydroxide and / or magnesium hydroxide per part.