JP2007302904A - Flame-retardant halogen-free epoxy resin composition, prepreg using the same and laminated plate for electric wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition that has excellent heat resistance, anti-tracking property, high safety and flame retardancy, and provide prepreg and laminated plate for electric wire board using the same. <P>SOLUTION: In an epoxy resin composition composed of epoxy resin, curing agent and additives, (a) the contents of halogen and antimony compounds are less than 0.1 wt.% in all of the materials, (b) at least one of the curing agent is a modified phenol resin being a polycondensate of a compound containing phenols and triazine ring and aldehyde and is dissolved in methyl ethyl ketone by less than 80 wt.% of solid component and additively, a novolac resin of phenols is mixed and (c) a flame-retardation-assisling action-having additive is included in this non-halogen epoxy resin composition (wherein the resin composition for sealing semiconductor is excluded). Further, the prepregs and laminated plate for electric wiring board using the non-halogen flame-retardant epoxy resin are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flame-retardant non-halogen epoxy resin composition suitable for an insulating material for electric wiring boards, a molding material, an adhesive, particularly an insulating material for glass-based epoxy resin electric wiring boards, a prepreg using the same, and an electric The present invention relates to a laminated board for wiring boards.

  Epoxy resin compositions are widely used mainly for electrical insulating materials due to their excellent electrical insulation properties, electrical properties, adhesion, mechanical properties of cured products, and the like. These electrical insulating materials are required to have high flame resistance from the viewpoint of safety, and are made flame retardant by using a halogen-based flame retardant, an antimony compound, or a phosphorus-based flame retardant together. However, in recent years, regulations on materials used for these are increasing from the viewpoint of environmental pollution and toxicity. In particular, toxicity and carcinogenicity of organic halogen substances such as dioxin are problematic, and reduction and elimination of halogen-containing substances are strongly demanded.

  Further, due to the problem of antimony carcinogenicity, there is an increasing demand for reduction and deletion of antimony compounds. Under such circumstances, alternatives with phosphorus flame retardants have been proposed and studied.

  However, when flame retardants are made mainly with phosphorus-based flame retardants, conductive tracks are likely to be formed under high voltage due to heat resistance, deterioration of characteristics due to moisture absorption, and flame retardant action due to promotion of carbonization, resulting in reduced tracking resistance. Come on. In addition, when phosphorus-based flame retardants containing red phosphorus as the main component are used, there are problems with ignitability and the harmfulness of phosphine gas generated during combustion. It was difficult to plan. The present invention solves these problems, and provides an epoxy resin composition having high heat resistance, tracking resistance, safety and excellent flame retardancy, a prepreg using the same, and a laminate for an electric wiring board. Aimed.

The present invention relates to an epoxy resin composition comprising an epoxy resin, a curing agent and an additive, wherein (a) all the materials have a halogen and antimony compound content of 0.1% by weight or less, and (b) the curing agent At least one is a polycondensate of phenols, a compound having a triazine ring and an aldehyde, which is a modified phenolic resin that is dissolved in methyl ethyl ketone at a solid content of 80% by weight or less, and further, a novolak resin of phenols is blended, (C) A flame retardant non-halogen epoxy resin composition (excluding a resin composition for semiconductor encapsulation) containing an additive having a flame retardant assisting action.
Further, the present invention comprises an epoxy resin, a curing agent and an additive. In the epoxy resin composition for producing a prepreg, (a) the content of all the materials is less than 0.1% by weight of halogen and antimony compounds. (B) a modified phenolic resin in which at least one of the curing agents is a polycondensate of phenols, a compound having a triazine ring and aldehydes, and is dissolved in methyl ethyl ketone at a solid content of 80% by weight or less, and further a novolak of phenols It is a flame retardant non-halogen epoxy resin composition comprising a resin and containing (c) an additive having a flame retardant auxiliary action.
In the present invention, the additive having a flame retardant assisting action is an inorganic filler, and preferably 30 to 250 parts by weight of the inorganic filler is blended with respect to a total of 100 parts by weight of the solid content of the epoxy resin and the curing agent, Moreover, it is preferable to mix an inorganic filler containing at least 30 parts by weight or more of an inorganic hydrate as the inorganic filler. Furthermore, the present invention is a modified phenol which is a polycondensate (addition condensate) of phenols, compounds having a triazine ring and aldehydes used in at least one of the curing agents and is dissolved in methyl ethyl ketone at a solid content of 80% by weight or less. When the resin is a combination of phenol and bisphenol A or phenol and alkylphenol, and the compound having a triazine ring is melamine, a preferred flame retardant non-halogen epoxy resin composition. And, as a curing agent, it is a polycondensate of at least phenols, a compound having a triazine ring, and a aldehydes, which is a polycondensate that dissolves in methyl ethyl ketone at a solid content of 80% by weight or less and a phenol novolak resin. Preferably, as the epoxy resin, a bisphenol A type epoxy resin having an epoxy equivalent of 400 to 600 g / eq is preferably blended by 50% by weight or more of the epoxy resin. Moreover, this invention is a flame-retardant non-halogen epoxy resin composition preferable in the said flame-retardant non-halogen epoxy resin composition not containing a phosphorus containing compound in order to improve tracking resistance. Then, a flame retardant non-halogen epoxy resin composition is used as a varnish, the substrate is impregnated and dried to produce a prepreg, and the same or different prepregs of this prepreg are used in combination, and a metal foil is laminated on one side or both sides thereof And a laminated board for electric wiring board obtained by heating and pressing. The base material used for the prepreg is preferably a woven fabric or a non-woven fabric, and the same kind of prepreg obtained from the woven fabric or the same kind of prepreg obtained from the non-woven fabric is used alone to form a laminate, or a nonwoven fabric such as a composite laminate. A prepreg obtained from a woven fabric is laminated on both sides of a prepreg obtained from the above, and a metal foil is further laminated on the outside thereof, followed by heating and pressing to obtain a laminate for an electric wiring board. And the flame-retardant non-halogen epoxy resin composition used for a woven fabric and a nonwoven fabric may be different if the composition is within the range.

  The flame-retardant non-halogen epoxy resin composition of the present invention, and prepregs and laminates for electrical wiring boards using the same have high heat resistance, tracking resistance, safety, and flame resistance. It is possible to provide a laminate that does not include the laminate.

  As a result of intensive studies on the flame retardant technique, the present inventors have determined that all materials in the epoxy resin composition comprising an epoxy resin, a curing agent, and an additive having a flame retardant assisting action have halogen and antimony compound contents. A modified phenolic resin that is 0.1% by weight or less and is a polycondensate of at least one of a curing agent with a phenol, a compound having a triazine ring, and an aldehyde and is dissolved in methyl ethyl ketone at a solid content of 80% by weight or less. The present invention has been completed by finding that the above-mentioned problems can be solved when an additive having a flame retardant assisting effect is used.

  As the epoxy resin in the present invention, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, bisphenol A novolac type epoxy resin, cresol novolac type epoxy resin, cyclic aliphatic epoxy resin, heterocyclic epoxy resin And diglycidyl ester epoxy resins, and these epoxy resins can be used singly or in combination. Further, when the flame retardant non-halogen epoxy resin composition of the present invention is used for a composite laminate obtained by combining with a woven or non-woven base material, bisphenol A having an epoxy equivalent of 400 to 600 g / eq as an epoxy resin. It is preferable to use 50% by weight or more of the epoxy resin in which the mold type epoxy resin is used because the moldability, characteristics, and cost are compatible. This is because the modified phenolic resin which is a polycondensate of phenols, compounds having a triazine ring and aldehydes as the curing agent used in the present invention is highly reactive and has an epoxy equivalent of less than 400 g / eq. This is because if the epoxy resin is used in an amount of 50% by weight or more in the epoxy resin, the curing is too fast, and the molding pressure becomes difficult to mold under a low pressure of less than 5 MPa, and warpage after normal and heat treatment becomes large. . In addition, if a bisphenol A type epoxy resin having an epoxy equivalent of more than 600 g / eq is used in an amount of 50% by weight or more in the epoxy resin, the heat resistance, flame retardancy, and glass transition temperature of the cured product are lowered.

  As phenols used to obtain a modified phenolic resin that is a polycondensate of phenols, triazine ring compounds and aldehydes used in the present invention and is soluble in methyl ethyl ketone at a solid content of 80% by weight or less, Polyphenols such as phenol, bisphenol A, bisphenol F, bisphenol S, alkylphenols such as cresol, xylenol, ethylphenol, butylphenol, aminophenol, phenylphenol, and the like may be used alone or in combination of two or more. Is possible. Preferably, when a combination of phenol and bisphenol A or a combination of phenol and alkylphenols is used, the reactivity at the time of curing when molding into a laminate is suppressed compared to the case of using phenol alone, and the moldability is excellent. It is preferable to use a combination of bisphenol A and alkylphenol because the flame retardancy is superior to that of a phenol resin used alone. Further, as a compound having a triazine ring, guanamine derivatives such as melamine or benzoguanamine and acetoguanamine, cyanuric acid or cyanuric acid derivatives such as methyl cyanurate and ethyl cyanurate, and isocyanuric acids such as isocyanuric acid or methyl isocyanurate and ethyl cyanurate And acid derivatives. Preferably, melamine, which has good heat resistance and flame retardancy and is inexpensive, is suitable. A compound having a triazine ring can be optimized in terms of flame retardancy, reactivity, heat resistance and the like by adjusting the N (nitrogen) content, for example, by changing the type and amount of use. Examples of aldehydes include, but are not limited to, formaldehyde, paraformaldehyde, trioxane, tetraoxymethylene, etc., but formaldehyde is preferred for ease of handling, and formaldehyde and paraformaldehyde are particularly preferred for reasons such as price. .

  The method for synthesizing the modified phenolic resin used in the present invention is based on the above-mentioned phenols, compounds having a triazine ring, and main ingredients of aldehydes at a desired N (nitrogen) content and a mixing ratio that gives a hydroxyl group equivalent. To react. As the catalyst at this time, a basic catalyst is preferable since the solubility of the compound having a triazine ring is good. Among them, amines are preferable because metals and the like remain as catalyst residues, which are not preferable as an electrical insulating material. The order of the reactions is not limited, and all the main materials can be reacted simultaneously, or the two main materials can be selectively reacted first, and stability control can be achieved by reacting in the presence of various solvents such as acetone and methyl ethyl ketone. Possible and preferred. The reaction product is subjected to neutralization, washing with water, heat treatment, distillation and the like in accordance with conventional methods to remove unreacted phenols, aldehydes, methylol groups, and solvent to obtain a modified phenol resin used in the present invention.

  Furthermore, it can be used as a curing agent in combination with several types of modified phenolic resins of curing agents used in the present invention, or in combination with other novolak resins of phenols. Since flame retardancy and heat resistance can be obtained, it is also preferable to use them in combination.

  Inorganic fillers are listed as additives that have a flame retardant auxiliary action, such as aluminum hydroxide, magnesium hydroxide, inorganic hydrates such as zeolite and hydrotalcite, clay, talc, wollastonite, mica, calcium carbonate, carbonic acid General-purpose inorganic fillers such as magnesium, alumina, silica, and glass powder, B (boron) such as zinc borate, zinc stannate, and zinc hydroxystannate, Sn (tin) filler, zinc oxide, tin oxide, etc. Metal oxides, inorganic phosphorus materials such as red phosphorus, and nitrates such as copper and zinc can be used without limitation. In addition, by using these inorganic fillers after being treated with a silane coupling agent or titanate coupling agent, the adhesion between the organic resin component and the inorganic filler is improved, and heat resistance, stability against temperature and humidity and safety are improved. This is preferable because of increased properties.

  In order to achieve the target flame retardancy by using only materials having a halogen and antimony compound content of 0.1% by weight or less, it is necessary to increase the content of the triazine ring in the epoxy resin composition. However, the N content in the organic resin solid content is limited to about 5% by weight. In order to achieve flame retardancy UL94V-1 or UL94V-0, other characteristics and moldability are ignored. Thus, it is considerably difficult unless a special epoxy resin is used or the amount of the modified phenolic resin of the present invention is extremely increased. Therefore, in order to achieve flame retardancy UL94V-1 or UL94V-0, an additive having a flame retardancy assisting action is required. An inorganic filler is preferable as an additive having a flame retardant assisting action, and it is preferable to add 30 to 250 parts by weight of the inorganic filler to 100 parts by weight of the total solids of the epoxy resin and the curing agent. It is preferable to use 30 parts by weight or more of an inorganic filler to reduce the proportion of flammable substances and to use 30 parts by weight or more of an inorganic hydrate as an inorganic filler in order to achieve flame retardancy UL94V-0. In order to improve tracking resistance, when not using a phosphorus containing compound, it is preferable to mix | blend 100 weight part or more of inorganic fillers. When the blending amount of the inorganic filler exceeds 250 parts by weight, the proportion of the inorganic filler is too large, and the nonwoven fabric or woven fabric base material is impregnated with the varnish of the flame retardant non-halogen epoxy resin composition and dried. The prepreg obtained has voids and uneven coating due to increased viscosity, and the resulting laminated board tends to be inferior in heat resistance, workability, insulation, and the like. Furthermore, when high-level heat resistance, workability, and insulation are required, flame retardance is assisted with inorganic fillers along with inorganic fillers, and the properties of laminates are further improved by reducing the amount of inorganic fillers. Can be made.

  Organic additives such as melamine derivatives such as melamine cyanurate and melamine phosphate, phosphate ester, phosphite ester, ammonium polyphosphate, nitrogen-containing phosphorus compound, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triphenyl phosphite Flame retardancy and heat resistance of various organophosphorus compounds such as thermosetting resin powders such as epoxy resins pre-cured, thermoplastic resins such as silicone compounds, polyphenylene ether, polyphenylene sulfide, and polyethylene terephthalate, or modified products thereof Therefore, it is effective to add it. However, as described above, when a phosphorus-containing compound is used, the flame retarding action promotes the formation of carbides and has an action of covering the surface portion with already burned substances, so that the tracking resistance is significantly deteriorated. Therefore, it is desirable not to use as much as possible when used in applications that require tracking resistance, and even when used, an epoxy resin that does not use a phosphorus-containing compound only in the portion where the tracking resistance of the outer layer portion of the laminate is required It is preferred to use a composition.

  As the base material used in the present invention, natural fiber base materials such as cotton and linter, organic synthetic fiber base materials such as aramid, polyvinyl alcohol, polyester and acrylic, and inorganic fiber base materials such as glass and asbestos are used. The From the viewpoint of flame retardancy, a glass fiber substrate is preferred. As the glass fiber base material, a woven fabric or a non-woven fabric using E glass, C glass, D glass, S glass or the like is preferable. Furthermore, what mixed glass fiber, a cellulose fiber, and organic fiber can also be used.

  Since the present invention uses a modified phenolic resin obtained by polycondensation of a compound containing a triazine ring containing N (nitrogen) which enhances flame retardancy with a phenol or aldehyde as a curing agent, the molecular structure in a stable state. Flame retardant non-halogen with high flame retardant and excellent balance with other characteristics by incorporating an inorganic filler as an additive having a flame retardant auxiliary action that takes in a large amount of N and further enhances the flame retardant It is possible to obtain an epoxy resin composition. In addition, as an inorganic filler, the combined use of flame retardants with different flame retardant effects and operating temperature ranges synergistically compared to the case where each flame retardant is used alone, higher flame retardancy and others It is possible to obtain a flame retardant non-halogen epoxy resin composition having an excellent balance with characteristics.

Examples 1 to 12 and Comparative Examples 1 to 3 will be described in detail below with reference to examples. However, the present invention is not limited to these examples. Table 1 shows the epoxy resins, curing agents, additives having a flame retardant auxiliary action, etc. used in Examples and Comparative Examples. Curing agents KA, B, and C in Table 1 are modified phenol resins obtained by the above-described method, and 0.35 parts by weight of triethylamine is added to 100 parts by weight of the solid content of the main material shown in Table 1. Added as a catalyst, reacted at 80 ° C. for 5 hours, then heated to 125 ° C. while removing water and reacted for 2 hours, then raised to 185 ° C. while removing water under normal pressure and then reduced pressure Then, unreacted phenol and the like were removed to obtain a modified phenolic resin. Then, a varnish is prepared by the method shown below, a prepreg is prepared by applying (impregnating and drying) to a base material, and heat and pressure molding is performed using this and a copper foil, and a laminate for an electric wiring board is formed. did. At least one epoxy resin and a curing agent are used so as to have the composition shown in Table 2, and the epoxy group of the epoxy resin and the hydroxyl group of the curing agent are compounded in an equivalent amount, and the total solid content of the epoxy resin and the curing agent is 100. Additives shown in Table 2 were blended with respect to parts by weight, and the solvent methyl ethyl ketone was added and stirred so that the solid content ratio in the varnish was 75 ± 3% by weight to prepare a varnish. The obtained varnish was impregnated into a glass cloth (thickness 0.2 mm, basis weight 210 g / m 2) so that the solid content was 52% by weight, and dried at 160 ° C. for 10 minutes to obtain a prepreg for the surface layer. Further, the varnish was impregnated into a glass nonwoven fabric (basis weight 73 g / m 2) so as to have a solid content of 89% by weight, and dried at 160 ° C. for 7 minutes to obtain a core layer prepreg. One surface layer prepreg is placed on each outer layer, and three core layer prepregs are laminated between them, and 18 μm thick electrolytic copper foil is placed on both outermost layers, at 170 ° C. for 80 minutes, Heating and pressure molding were performed at 4 MPa to obtain a double-sided copper-clad composite laminate having a thickness of 1.6 mm. The resulting composite laminate was measured for flame retardancy, moldability, tracking resistance, copper foil peel strength, and solder heat resistance with copper foil, and the results are shown in Table 2.
In addition, the measuring method was performed as follows.
Flame retardancy: tested by UL94 vertical test method.
Formability: The copper foil of the composite laminate was removed by etching, and the occurrence of voids was mainly evaluated. Good with no voids, marked with ◎, with slight voids marked with ◯, with voids marked with △, voids on the entire surface, and the periphery of the laminate became thinner What was being evaluated was evaluated as x.
Tracking resistance: The copper foil of the composite laminate was removed by etching, 50 × 50 mm test pieces were prepared, electrodes were set at intervals of 4 mm, and 0.1 mL of ammonium chloride was applied at intervals of 30 seconds while applying a constant voltage. A weight% electrolytic solution was dropped from a syringe, and the number of drops until the test surface was tracking broken was determined. Next, the voltage was changed to create a relationship curve between the voltage and the number of drops, and the voltage (CTI) corresponding to 50 drops was obtained.
Copper foil peel strength: Measured according to JIS C6481.
Solder heat resistance with copper foil: Prepare a test piece in a size of 25 x 25 mm with the copper foil attached to the composite laminate, float it in a solder bath at 260 ° C, and the time until blistering or peeling occurs Was measured.

  Comparative Examples 1 and 2 are cases where a bisphenol A type novolak resin is used as the curing agent, but even when an inorganic filler is blended (Comparative Example 2), the flame retardancy is poor. And although the comparative example 3 is a case where the modified phenol resin which polycondensed phenol, a benzoguanamine, and formaldehyde was used for the hardening | curing agent, since the additive was not mix | blended, it was inferior in the flame retardance and it burned. In Comparative Examples 3, the same epoxy resin and curing agent were blended, and Examples 1 to 3, which were blended with an additive having a flame retardancy assisting action, had flame retardancy of UL-V0, V-1, and were flame retardant. Excellent. When the compounding amount of the additive is increased to 250 parts by weight as in Example 3, the flame retardancy and tracking resistance are excellent, but the moldability and the copper foil peel strength are inferior. Moreover, Examples 4-7 which mix | blended the modified phenol resin which used melamine for the hardening | curing agent improved heat resistance, and also Example 8, 10-12 which mix | blended the modified phenol resin which used bisphenol A together is shaping | molding. And heat resistance are improved. Examples 6, 8, 9, 11, and 12 in which the epoxy equivalent of the used epoxy resin is in the range of 400 to 600 are excellent in moldability and can provide a laminate without voids. Also in Example 10 in which an epoxy resin is used in combination, the moldability is good. In Examples 11 and 12, the compounding amount of aluminum hydroxide (additive TA) was reduced from 150 parts by weight of Example 8 to 100 parts by weight, and melamine cyanurate (additive TC) or phosphate ester compound was reduced. In this case, 8 parts by weight of (T-D) were further blended, but the flame retardancy and formability were equivalent, and the solder heat resistance was improved. The tracking resistance is inferior in Example 11 containing phosphorus, but is improved as compared with Comparative Examples 1 and 3 in which no additive is added. Thus, by setting it as a flame retardant non-halogen epoxy resin composition containing an epoxy resin, a phenols as a curing agent, a polycondensate of a compound having a triazine ring and a polycondensate of aldehydes and an additive having a flame retardant auxiliary action, The laminate can be flame retardant. And the laminated board which is excellent in a moldability and does not have a void etc. can be obtained by mix | blending what has the epoxy equivalent of an epoxy resin in the range of 400-600. Furthermore, when the organic filler is used in combination with the inorganic filler, the amount of the inorganic filler can be reduced, and the solder heat resistance and the like are improved. However, it is preferable to avoid phosphorus-containing compounds because they reduce tracking resistance.

Claims (10)

  In the epoxy resin composition comprising an epoxy resin, a curing agent, and an additive, (a) all materials have a halogen and antimony compound content of 0.1% by weight or less, and (b) at least one of the curing agents is phenol. A modified phenolic resin that is a polycondensate of a compound having a triazine ring and an aldehyde and dissolved in methyl ethyl ketone at a solid content of 80% by weight or less, and further, a novolak resin of phenol is blended, and (c) difficult A flame retardant non-halogen epoxy resin composition containing an additive having a combustion assisting action (except for a semiconductor sealing resin composition).   An epoxy resin composition for preparing a prepreg comprising an epoxy resin, a curing agent and an additive, wherein (a) all materials have a halogen and antimony compound content of 0.1% by weight or less, and (b) a curing agent. At least one of these is a polycondensate of phenols, compounds having a triazine ring and aldehydes, which is a modified phenolic resin that dissolves in methyl ethyl ketone at a solid content of 80% by weight or less, and further comprises a novolak resin of phenols. (C) A flame retardant non-halogen epoxy resin composition containing an additive having a flame retardant auxiliary action.   A modified phenolic resin, which is a polycondensate of phenols, compounds having a triazine ring and aldehydes used in at least one of the curing agents and dissolved in methyl ethyl ketone at a solid content of 80% by weight or less, is phenol and bisphenol A or phenol and alkylphenol. The flame retardant non-halogen epoxy resin composition according to claim 1, wherein the compound having a triazine ring is melamine.   The additive having a flame retardant assisting action is an inorganic filler, and 30 to 250 parts by weight of the inorganic filler is blended with respect to a total of 100 parts by weight of the solid content of the epoxy resin and the curing agent. The flame-retardant non-halogen epoxy resin composition described in 1.   The flame retardant non-halogen epoxy resin composition according to claim 4, wherein an inorganic filler containing at least 30 parts by weight of an inorganic hydrate is blended as the inorganic filler.   The flame retardant non-halogen epoxy resin according to any one of claims 1 to 5, wherein a bisphenol A type epoxy resin having an epoxy equivalent of 400 to 600 g / eq is blended as an epoxy resin by 50% by weight or more of the epoxy resin. Composition.   The flame-retardant non-halogen epoxy resin composition according to any one of claims 1 to 6, wherein the flame-retardant non-halogen epoxy resin composition does not contain a phosphorus-containing compound.   A prepreg obtained by impregnating and drying a base material using the flame retardant non-halogen epoxy resin composition according to any one of claims 1 to 7 as a varnish.   The prepreg according to claim 7, wherein the substrate is a woven fabric or a nonwoven fabric.   A laminate for an electrical wiring board obtained by using the same or different prepregs according to claim 8 or 9 in combination, laminating a metal foil on one or both sides, and heating and pressing.