JP2010116421A - Resin composition for composite laminate, and composite laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for use in an intermediate layer of a composite laminate that has advanced flame retardancy without addition of a halogen-containing compound and is excellent in cost performance, and to provide the composite laminate. <P>SOLUTION: This resin composition is used for the intermediate layer of the composite laminate. The resin composition for the composite laminate includes a bisphenol epoxy resin, a triazine-modified phenol novolac resin, a phosphorous flame retardant, and an inorganic filler. In the resin composition, a ratio of the number of epoxy groups of the bisphenol epoxy resin to the number of OH groups of the triazine-modified phenol novolac resin (epoxy group/OH group) is 1.2 to 2.0. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition for a composite laminate and a composite laminate.

  As consumer electronics and industrial electronics are becoming smaller and more advanced, circuit boards to which high voltage is applied such as computers and measuring instruments are loaded with heavy objects such as transformers and transistors. From the viewpoint of strength, an epoxy resin glass copper clad laminate or an epoxy resin composite copper clad laminate is often used. In addition to this, in order to increase the density, there is a demand for a substrate with excellent tracking resistance from the standpoint of ensuring safety. Therefore, an epoxy resin composite copper-clad laminate with excellent tracking performance and cost performance is required. The demand for plates is increasing.

On the other hand, thermosetting resins typified by epoxy resins are widely used in electrical and electronic equipment parts due to their excellent characteristics, and in some cases they are given flame retardancy to ensure safety against fire. Many. Conventionally, halogen-containing compounds such as brominated epoxy resins are generally used to make these resins flame-retardant. However, these halogen-containing compounds have a high degree of flame retardancy, but particularly aromatic bromine compounds have a heat resistance. In addition to separation of corrosive bromine and hydrogen bromide by decomposition, there is a possibility of forming highly toxic polybromodibenzofuran and polydibromobenzoxine when decomposed in the presence of oxygen. In addition, it is extremely difficult to treat old waste materials and waste containing bromine. For these reasons, phosphorus compounds are widely studied as flame retardants to replace bromine-containing flame retardants (for example, Patent Document 1). However, when a phosphorus compound alone is used in the epoxy resin system, a large amount of phosphorus compound is required to obtain sufficient flame retardancy, and the cost of the copper-clad laminate is increased.
JP 2003-072011 A

  The present invention has been made in view of the above circumstances, and is a composite laminate used for an intermediate layer of a composite laminate having high flame retardancy and excellent cost performance without adding a halogen-containing compound. It is providing the resin composition for boards and a composite laminated board.

  The resin composition according to the present invention is a resin composition used for an intermediate layer of a composite laminate, and includes a bisphenol-type epoxy resin, a triazine-modified phenol novolac resin, a phosphorus flame retardant, and an inorganic filler. It is characterized by.

  In this composite laminate resin composition, a bisphenol-type epoxy resin is used as the epoxy resin. As a result, when only a phosphorus compound is used as a flame retardant in an epoxy resin composite laminate, it is necessary to add a large amount of phosphorus compound to obtain sufficient flame retardancy, and as a general-purpose material, the product cost increases. However, by using an inexpensive bisphenol type epoxy resin as the epoxy resin, it is possible to provide a resin composition for a composite laminate that can suppress the product cost while maintaining flame retardancy.

  The ratio of the number of epoxy groups of the bisphenol-type epoxy resin to the number of OH groups of the triazine-modified phenol novolak resin is preferably epoxy group / OH group = 1.2 to 2.0. Thereby, it can be set as the resin composition for composite laminated boards which made the flame retardance and heat resistance compatible.

  Moreover, the composite laminated board which used said resin composition for composite laminated boards for the intermediate | middle layer of the composite laminated board can be provided.

  According to the present invention, a resin composition for a composite laminate and a composite laminate used for an intermediate layer of a composite laminate having high flame retardancy and excellent cost performance without adding a halogen-containing compound Can be provided.

  The resin composition for a composite laminate of the present invention is a resin composition used for an intermediate layer of a composite laminate, and is a bisphenol type epoxy resin, a triazine-modified phenol novolac resin, a phosphorus flame retardant, and an inorganic filler. Including.

  The composite laminate is a laminate in which the base material used for the surface layer and the intermediate layer is a different combination. A surface layer composed of a glass woven fabric impregnated with a thermosetting resin as a base material, and a structure laminated with a pair of surface layers sandwiched between cellulose paper and a glass nonwoven fabric, impregnated with a thermosetting resin. It is formed with an intermediate layer.

  The resin composition used for the intermediate layer of the composite laminate of the present invention uses a bisphenol type epoxy resin. Bisphenol type epoxy resins include bisphenol A type, bisphenol S type, bisphenol F type, etc., and these can be used alone or in combination of two or more, but for further cost reduction, bisphenol A type It is preferable to use an epoxy resin. The content of the bisphenol-type epoxy resin is preferably 25 parts by weight or more and 70 parts by weight or less with respect to 100 parts by weight in total of the bisphenol-type epoxy resin, the triazine-modified phenol novolac resin, and the phosphorus flame retardant. If the content is within this range, it is preferable in terms of combustion resistance.

  The resin composition used for the intermediate layer of the composite laminate of the present invention uses a triazine-modified phenol novolac resin. Thereby, adhesiveness can be improved, maintaining heat resistance. Further, by using a triazine-modified phenol novolac resin as a curing agent for the bisphenol-type epoxy resin, adhesion can be imparted without reducing the water absorption rate or solder heat resistance. Since the triazine-modified phenol novolac resin contains a nitrogen atom in the molecule, the adhesion is improved. Further, the water absorption rate is not deteriorated. Furthermore, since the heat resistance of the triazine ring structure is high and the solubility in the bisphenol type epoxy resin is excellent, the solder heat resistance is not deteriorated. The nitrogen content of the triazine-modified phenol novolac resin used in the present invention is preferably 8 to 20% by weight. When the content is not less than the lower limit, the water absorption rate is improved, and when the content is not more than the upper limit, the adhesion is improved. The content of the triazine-modified phenol novolac resin is not particularly limited, but is preferably 20 parts by weight or more and 60 parts by weight or less, and particularly preferably 30 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the bisphenol type epoxy resin. Further, the triazine-modified phenol novolac resin preferably has a nitrogen content of 8% by weight or more because the effect on flame retardancy is small when the nitrogen content is low.

  As the curing agent, those other than the triazine-modified phenol novolac resin can be used in combination. For example, phenol novolac resin, aromatic amine, etc. Among them, phenol aralkyl resin or naphthalene aralkyl resin is particularly preferable because of its low water absorption and high flame retardancy. Further, since the hydroxyl group equivalent is larger than that of the phenol novolac resin, the curing shrinkage is small and the adhesion is excellent. For this reason, when a phenol aralkyl resin and a naphthalene aralkyl resin are used in combination, it is possible to improve laminate properties such as adhesion and moisture absorption solder heat resistance.

  The ratio of the number of epoxy groups of the bisphenol type epoxy resin to the number of OH groups of the triazine-modified phenol novolac resin is epoxy group / OH group = 1.2 to 2.0, more preferably 1.3 to 1.7. When the ratio of epoxy group / OH group is at the lower limit, the flame resistance is excellent, and when the ratio is close to the upper limit, the heat resistance is excellent.

  Phosphorus flame retardants include reactive phosphorus flame retardants and additive phosphorus flame retardants. Reactive phosphorus flame retardants have a functional group that reacts with phenolic resins, and are used when molded into laminates. Since it reacts with the phenol resin, characteristics such as electrical characteristics and water absorption are not deteriorated even under various processing conditions of the laminate. On the other hand, there are many types of additive-type phosphorus flame retardants, and there are those that do not easily deteriorate the laminate properties, those that have high flame retardancy, and the like, which can be appropriately selected according to required properties and costs. From the viewpoint of cost, an additive type phosphorus flame retardant is preferable.

  Examples of the reactive phosphorus flame retardant include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, resorcyl diphenyl phosphate, phenyl phosphonic acid, diphenyl phosphonic acid, and the like. Examples of the additive type include phenoxyphosphazene, phosphonitrile acid phenyl ester, cresyl diphenyl phosphate, triallyl phosphate, and dimethylmethyl phosphonate. Of these, phenoxyphosphazene is preferred. Since the phosphorus content is large, flame resistance can be imparted by adding a small amount.

  The phosphorus flame retardant content is 0.5 parts by weight or more and 5 parts by weight or less with respect to a total of 100 parts by weight of the bisphenol type epoxy resin, the triazine-modified phenol novolac resin, and the phosphorus flame retardant. If it is less than 0.5 part by weight, the effect on flame retardancy is small, and if it exceeds 5 parts by weight, the heat resistance is lowered, which is not preferable.

  The resin composition for composite laminates in the present invention uses an inorganic filler. Examples of inorganic fillers include, but are not limited to, silicates such as talc, fired clay, unfired clay, mica and glass, oxides such as titanium oxide, alumina, silica and fused silica, calcium carbonate, magnesium carbonate, Carbonates such as hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, sulfates or sulfites such as barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, boron Examples thereof include borates such as aluminum oxide, calcium borate and sodium borate, and nitrides such as aluminum nitride, boron nitride and silicon nitride. Among these, it is more preferable to use aluminum hydroxide and magnesium hydroxide in combination because heat resistance can be further improved while maintaining high flame resistance.

  The inorganic filler is preferably contained in an amount of 100 parts by weight or more and 250 parts by weight or less based on 100 parts by weight in total of the bisphenol A type epoxy resin, the triazine-modified phenol novolac resin, and the phosphorus flame retardant. If it is less than 100 parts by weight, the effect of improving flame retardancy is small, and the linear expansion coefficient of the laminate tends to increase. Adding over 250 parts by weight is difficult because the resin viscosity is high and uniform dispersion in the resin is difficult, and impregnation into the glass nonwoven fabric is reduced.

  A glass nonwoven fabric is impregnated with a flame retardant epoxy resin composition comprising the bisphenol A type epoxy resin, triazine-modified phenol novolac resin, phosphorus flame retardant, and inorganic filler component to obtain a prepreg as an intermediate layer. An epoxy resin-impregnated glass cloth prepreg and, if necessary, a copper foil are overlaid on the surface layer and a predetermined number of intermediate layer prepregs, and then heat-pressed to obtain a composite laminate.

  As the epoxy resin composition of the surface layer, a non-brominated epoxy resin is a main component, does not contain phosphorus or a phosphorus compound, and aluminum hydroxide and inorganic filler as a total of 100 parts by weight of the epoxy resin and the curing agent Alternatively, a glass woven fabric impregnated with an epoxy resin composition containing 10 to 200 parts by weight of magnesium hydroxide is used. If the content is less than 10 parts by weight, the effect on the tracking resistance is low, and if it exceeds 200 parts by weight, the resin viscosity becomes too high and impregnation into the glass woven fabric becomes difficult. However, in this case, the flame retardancy of the surface layer may not be sufficient. Therefore, when the volume ratio of the surface layer is greater than 40% with a thin laminated plate having a thickness of 1 mm or less, the blending amount of the inorganic filler If the amount is less than 50 parts by weight, the flame retardancy is insufficient, so an epoxy resin composition containing 50 to 200 parts by weight is used.

  In the epoxy resin of the surface layer, brominated epoxy resin is very easily carbonized, so that tracking resistance is poor and it is essential to use non-brominated epoxy resin. Further, the content of aluminum hydroxide and / or magnesium hydroxide is preferably 20 to 150 parts by weight with respect to a total of 100 parts by weight of the epoxy resin and the curing agent, and is a thin laminate having a thickness of 1 mm or less. When the volume ratio of becomes larger than 40%, 50 to 150 parts by weight is preferable. In this range, it has excellent tracking resistance and flame retardancy, and has good impregnation into glass woven fabric, so that other characteristics such as electrical characteristics and mechanical characteristics are also satisfactory.

  In order to impart tracking resistance, in addition to aluminum hydroxide and magnesium hydroxide, inorganic fillers such as silica, talc, mica and clay can be blended, but from the point of flame retardancy, aluminum hydroxide, Magnesium hydroxide is preferred. The reason why the inorganic filler compounded in the epoxy resin of the surface layer improves the tracking resistance is thought to be because the inorganic filler is present on the surface of the formed laminate, thereby reducing the proportion of the resin on the surface. It is done. As the inorganic filler, aluminum hydroxide (hydrated alumina) is particularly preferable, because the aluminum hydroxide decomposes by the heat of discharge to generate water, and the water and the organic matter decomposed by the discharge react. This is because the formation of a track is prevented by generating a volatile substance.

  In addition, if phosphorus or a phosphorus compound is included in the surface layer to improve flame retardancy, the peel strength of the copper foil may decrease, which may hinder the repair work of the electronic component or may be mounted electronic component. Problems such as a decrease in reliability may occur. 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 laminated board. The solvent to be used needs to exhibit good solubility with respect to a part of the composition, but a poor solvent may be used as long as it does not have an adverse effect as a part of the solvent.

Hereinafter, the present invention will be specifically described by way of examples. Parts indicate parts by weight.
Example 1
After dissolving 0.28 parts of 2-phenyl-4-methylimidazole in 66.3 parts of acetone, 55.2 parts of bisphenol A type epoxy resin (Epicron 850, Ep equivalent 190 manufactured by Dainippon Ink and Chemicals), triazine-modified phenol novolak The mixed resin solution A was obtained by dissolving 22.1 parts by weight of resin (LA-7054, manufactured by Dainippon Ink and Chemicals, Inc.) and 22.7 parts by weight of phenoxyphosphazene (SPB-100, manufactured by Otsuka Chemical Co., Ltd.). . Further, 88.4 parts of aluminum hydroxide and 88.4 parts of magnesium hydroxide were added to the obtained mixed resin solution A, and the mixture was stirred and dispersed to prepare varnish A. Using this varnish A, 100 parts of glass nonwoven fabric (thickness 0.4 mm, manufactured by Nippon Vilene) was impregnated with 700 parts of varnish solids and dried with a drying cylinder at 150 ° C. for 5 minutes to prepare a glass nonwoven fabric prepreg. .

  Next, 0.15 part of 2-phenyl-4-methylimidazole and 2 parts of dicyandiamide are dissolved in a mixture of 29.4 parts of acetone and 19.6 parts of methyl cellosolve, and then non-brominated bisphenol A type epoxy resin. 97.9 parts (Ep-850 manufactured by Yuka Shell) were dissolved to obtain a mixed resin solution B. Furthermore, 48.9 parts by weight of aluminum hydroxide was added to the obtained mixed resin solution B, and the mixture was stirred and dispersed to prepare varnish B. This varnish B was impregnated with 100 parts by weight of glass woven cloth (thickness: 0.18 mm, manufactured by Nitto Boseki) with 100 parts by weight of varnish solid, and dried for 5 minutes with a drying cylinder at 150 ° C. to prepare a glass woven cloth prepreg. .

  One glass woven prepreg is stacked on the top and bottom of three glass nonwoven fabric prepregs, and an electrolytic copper foil with a thickness of 18 μm is further stacked on the top and bottom, followed by heating and pressing at a pressure of 2 MPa and a temperature of 170 ° C. for 120 minutes, A 1.6 mm double-sided copper-clad composite laminate was obtained.

  A double-sided copper clad composite laminate was prepared in the same manner as in Example 1 except for Examples 2 to 7 and Comparative Examples 1 to 4 shown in Table 1 except for the formulation. The evaluation results are shown in the lower column of Table 1. The laminates obtained in the examples are all excellent in flame resistance and solder heat resistance, and also have good tracking resistance and copper foil peeling strength.

The method for measuring the characteristics of the obtained laminate is as follows.
1. Tracking resistance: After etching the copper foil, the applied voltage value was determined when no short circuit occurred even when 50 drops or more of 0.1% ammonium chloride aqueous solution was dropped.
2. Solder heat resistance: Measured according to JIS C 6481, subjected to a moisture absorption treatment for 2 hours after boiling, and then checked for abnormal appearance after floating in a solder bath at 260 ° C. for 180 seconds.
○: No abnormality, ×: Dandruff occurred Copper foil peel strength: measured according to JIS C 6481 Flame retardancy: Evaluated by vertical method according to UL-94 standard.

Claims (9)

A resin composition used for an intermediate layer of a composite laminate,
A resin composition for a composite laminate comprising a bisphenol-type epoxy resin, a triazine-modified phenol novolac resin, a phosphorus flame retardant, and an inorganic filler.   2. The resin for composite laminates according to claim 1, wherein the ratio of the number of epoxy groups of the bisphenol-type epoxy resin to the number of OH groups of the triazine-modified phenol novolac resin is epoxy group / OH group = 1.2 to 2.0. Composition.   The resin composition for composite laminates according to claim 1 or 2, wherein the bisphenol-type epoxy resin has a number average molecular weight of 5000 or less.   The resin composition for a composite laminate according to any one of claims 1 to 3, wherein the bisphenol type epoxy resin contains a bisphenol A type epoxy resin.   The resin composition for a composite laminate according to any one of claims 1 to 4, wherein the inorganic filler contains aluminum hydroxide or magnesium hydroxide.   The inorganic filler is 100 parts by weight or more and 250 parts by weight or less with respect to 100 parts by weight of the bisphenol type epoxy resin, the triazine-modified phenol novolac resin, and the phosphorus flame retardant. 5. The resin composition for composite laminates according to any one of 4 to 4.   The phosphorus component content of the phosphorus flame retardant is 0.5 parts by weight or more in a total of 100 parts by weight of the bisphenol type epoxy resin, the triazine-modified phenol novolac resin, and the phosphorus flame retardant. The resin composition for composite laminates according to any one of claims 1 to 5, which is contained in an amount of not more than parts by weight.   The resin composition for a composite laminate according to any one of claims 1 to 7, wherein the phosphorus flame retardant is an additive type phosphorus flame retardant.   A composite laminate using the resin composition for a composite laminate according to claim 1 as an intermediate layer.