JP2005281488A - Resin composition, prepreg and laminated plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition that has improved shelf life in the form of prepreg, in other words, in the tack dry state, and can produce laminated plates for printed wiring board that gives high glass transition point after curing and shows excellent adhesion and heat resistance and provide prepreg and laminated plates using the composition. <P>SOLUTION: This resin composition includes, as resin components, a bisphenol A type epoxy resin, a cresol novolac type epoxy resin and, as a curing component, dicyandiamide and 4,4'-diaminodiphenyl sulfone. Prepreg is prepared by placing the resin composition on a sheet-like fibrous base material and laminate plates are produced by the thermal compression-molding of the prepreg. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin composition, a prepreg and a laminate using the resin composition.

  Along with the remarkable development of electronic devices in recent years, high performance and high reliability of printed wiring boards are required. Therefore, required characteristics for laminated boards, which are materials used for printed wiring boards, such as heat resistance, conductors, etc. The adhesion with the circuit is also higher.

Examples of a method for obtaining a laminated board for printed wiring board having excellent heat resistance include a method using a laminated board having a high glass transition temperature.
As a method for obtaining a laminated sheet having a high glass transition temperature, for example, a resin composition comprising a single or plural types of epoxy resins, a phenol novolac resin as an epoxy resin curing agent, an amine compound, and an imidazole as a curing accelerator A glass fiber substrate or the like is impregnated with a resin varnish containing an organic solvent and then dried, and the necessary number of prepregs are laminated, and metal foil or plastic film is placed above and below it. The method of manufacturing by pressure molding is mentioned (for example, refer patent document 1).

The laminate thus obtained is known to have a high crosslinking density and excellent adhesion, heat resistance and moisture resistance.
However, the laminate obtained in this way is easily cured due to its high reactivity, and the preservability in a semi-cured state in the prepreg may not be sufficient.

JP 2000-273148 A

  The present invention provides a printed wiring board laminate having improved storability in a prepreg state, that is, in a semi-cured state, and having a high glass transition point after curing and excellent adhesion and heat resistance. A resin composition that can be used, and a prepreg and a laminate using the resin composition are provided. For this purpose, it is necessary to find a resin composition having a lower reactivity than normal at room temperature and having the same adhesion and heat resistance after the curing reaction.

Such an object is achieved by the following (1) to (8) of the present invention.
(1) A resin composition comprising bisphenol A type epoxy resin and cresol novolac type epoxy resin as resin components, and dicyandiamide and 4,4′-diaminodiphenylsulfone as curing agent components.
(2) The resin composition according to (1), further comprising a curing accelerator.
(3) The resin composition according to (2), wherein the curing accelerator is an imidazole compound.
(4) The resin according to any one of (1) to (3) above, which contains 70 to 90% by weight of a bisphenol A type epoxy resin and 10 to 30% by weight of a cresol novolac type epoxy resin with respect to the entire resin component. Composition.
(5) The resin composition according to any one of (1) to (4), wherein the content of the dicyandiamide is 0.3 to 0.45 equivalents relative to the epoxy group of the resin component.
(6) The content of the 4,4′-diaminodiphenyl sulfone is 0.05 to 0.3 equivalent to the epoxy group of the resin component, according to any one of (1) to (5) above Resin composition.
(7) The resin composition according to any one of (3) to (6), wherein the content of the imidazole is 0.1 to 0.2% by weight with respect to the entire resin component.
(8) A prepreg obtained by supporting the resin composition according to any one of (1) to (7) on a sheet-like fiber base material.

  The present invention uses a resin composition characterized by containing bisphenol A type epoxy resin and cresol novolac type epoxy resin as resin components, and dicyandiamide and 4,4′-diaminodiphenylsulfone as curing agent components, and the same. A prepreg and a laminate, which can improve the storage stability in a prepreg state, have a high glass transition point, and have excellent adhesion and heat resistance can be obtained.

Hereinafter, the resin composition, prepreg and laminate of the present invention will be described in detail.
The resin composition of the present invention is characterized by containing bisphenol A type epoxy resin and cresol novolac type epoxy resin as resin components and dicyandiamide and 4,4′-diaminodiphenylsulfone as curing agent components.
The prepreg of the present invention is characterized in that the resin composition of the present invention is supported on a glass fiber substrate.
And the laminated board of this invention is formed by heat-press-molding the said prepreg of this invention.
First, the resin composition of the present invention will be described in detail.

  The resin composition of the present invention uses bisphenol A type epoxy resin and cresol novolac type epoxy resin as resin components. By using a bisphenol A type resin and a cresol novolac type epoxy resin in combination, adhesion and heat resistance after curing of the resin composition can be imparted.

  Although it does not specifically limit as a content rate of each resin component, It is preferable that they are 70 to 90 weight% of bisphenol A type epoxy resins, and 10 to 30 weight% of cresol novolak type epoxy resins with respect to the whole resin component. Thereby, the said effect can be expressed with sufficient balance.

  The resin composition of the present invention is characterized in that dicyandiamide and 4,4'-diaminodiphenylsulfone are used in combination as a curing agent for the resin component.

Dicyandiamide and 4,4′-diaminodiphenylsulfone are both used as curing agents for epoxy resins. For example, when dicyandiamide is used alone, certain characteristics are obtained as heat resistance and adhesion after curing. However, it may be difficult to further improve heat resistance and adhesion. Further, when the content is increased, the moisture absorption amount increases and the moisture absorption solder heat resistance may be lowered.
On the other hand, when 4,4′-diaminodiphenyl sulfone is used alone, the basicity is low and the curing is slow, so that the storability in the prepreg state, that is, the semi-cured state can be improved, but only dicyandiamide is used. Compared to the case, the crosslinking density may be lowered, and the heat resistance and adhesion may be lowered.
In the resin composition of the present invention, the combination of dicyandiamide having such properties and 4,4′-diaminodiphenylsulfone improves the storability in the prepreg state, and the glass transition after curing. It is possible to obtain a resin composition capable of obtaining a laminate having high temperature and excellent adhesion and heat resistance.

In the resin composition of the present invention, the content of the curing agent is not particularly limited, but the content of dicyandiamide is preferably 0.3 to 0.45 equivalent to the epoxy group of the resin component, More preferably, it is 0.35-0.4 equivalent.
Further, the content of 4,4′-diaminodiphenyl sulfone is preferably 0.05 to 0.3 equivalent, more preferably 0.1 to 0.2 with respect to the epoxy group of the resin component. .
In the resin composition of this invention, the said characteristic can be expressed effectively especially by using two types of hardening | curing agents with the said compounding quantity.
When the blending amount of the curing agent is less than the lower limit, the resin composition may not be sufficiently cured during molding. On the other hand, if the above upper limit is exceeded, the curing time may be too short to cause molding failure, or the storability of the prepreg in a semi-cured state may deteriorate.

The resin composition of the present invention may contain a curing accelerator in addition to the above curing agent. Thereby, a hardening rate can be raised or a hardening temperature can be lowered | hung.
Although it does not specifically limit as a hardening accelerator used in the resin composition of this invention, For example, tertiary amine compounds, such as benzyldimethylamine and 2,4,6-trisdimethylaminomethylphenol, 2-methylimidazole, 2- Examples include imidazole compounds such as ethyl-4-methylimidazole.

  Among these, it is preferable to use an imidazole compound. Thereby, the said effect can be expressed by addition of a small amount, without affecting the characteristic of a prepreg or a laminated board.

In the resin composition of the present invention, the content of the curing accelerator is not particularly limited. For example, when an imidazole compound is used, the content is 0.1 to 0.2% by weight with respect to the resin component. preferable.
When the blending amount of the imidazole compound is less than the above lower limit value, the resin composition may not be sufficiently cured during molding. On the other hand, if the above upper limit is exceeded, the curing time may be too short to cause molding failure, or the storability of the prepreg in a semi-cured state may deteriorate.

  Next, the prepreg of the present invention will be described. The prepreg of the present invention is characterized in that the resin composition of the present invention is supported on a sheet-like fiber base material (hereinafter sometimes simply referred to as “base material”).

The method for supporting the resin composition on the substrate is not particularly limited. For example, the resin composition of the present invention is dissolved in an organic solvent to prepare a resin varnish, and the substrate is immersed in the resin varnish. Various coaters Examples thereof include a method of applying a resin varnish to a substrate with an apparatus and a method of spraying a resin varnish onto a substrate with a spray device.
Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition with respect to a base material can be improved. In addition, when a base material is immersed in a resin varnish, a normal impregnation coating equipment can be used.

  Although it does not specifically limit as a base material used in this invention, For example, organic fiber woven fabrics, such as paper, a woven fabric of glass fiber, a nonwoven fabric of glass fiber, a polyamide resin, a polyester resin, etc. are mentioned. Among these base materials, glass fiber base materials are preferable in consideration of strength and water absorption.

The organic solvent used for the preparation of the resin varnish is not particularly limited as long as the epoxy resin, the curing agent, and the curing accelerator can be uniformly dissolved. For example, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, ethylene glycol Examples thereof include ethers such as monomethyl ether and propylene glycol monomethyl ether, N, N-dimethylformamide and the like. Among these, N, N-dimethylformamide is particularly preferable because the resin composition has good solubility and low volatility.
Although it does not specifically limit as solid content in the said resin varnish, 40 to 80 weight% is preferable and 45 to 65 weight% is especially preferable.

  The prepreg of the present invention can be obtained, for example, by immersing the substrate in the resin varnish and drying at a predetermined temperature, for example, 150 to 200 ° C. At this time, the impregnation amount of the resin composition in the prepreg (ratio of the solid content of the resin composition with respect to the entire prepreg) is preferably 45 to 60% by weight. Outside the above range, adhesion and formability may be reduced during the formation of the laminated sheet.

Next, the laminated board of this invention is demonstrated.
The laminate of the present invention is formed by heating and pressing the prepreg of the present invention. Specifically, it can be obtained by using at least one or more of the above prepregs, overlaying a metal foil or a plastic film on both upper and lower surfaces or one surface, and heating and pressing.

  The heating and pressing conditions are not particularly limited, but the temperature is preferably 120 to 220 ° C, particularly preferably 150 to 200 ° C. Moreover, although a pressure is not specifically limited, 2-5 Mpa is preferable and 2.5-4 Mpa is especially preferable.

Moreover, as a metal which comprises metal foil, copper, a copper-type alloy, aluminum, an aluminum-type alloy etc. are mentioned, for example. The thickness of the metal foil is preferably 3 to 70 μm, particularly preferably 12 to 35 μm.
Moreover, as a plastic film, a polypropylene film, a polyethylene terephthalate film, etc. can be used.

Hereinafter, although an example and a comparative example explain the present invention, the present invention is not limited to this.

(Example 1)
(1) Preparation of resin varnish 113.3 g of bisphenol A type epoxy resin as resin component, 21.4 g of cresol novolac type epoxy resin, 1.6 g of dicyandiamide as a curing agent component, 1.7 g of 4,4′-diaminodiphenylsulfone, 2 -Phenyl-4-methylimidazole 0.15g was mix | blended, the dimethylformamide 46g was added to this, and the resin varnish was prepared so that the solid content of the resin varnish might be 56 weight%.

(2) Manufacture of prepreg Using the above resin varnish, 100 parts by weight of a resin fiber varnish was impregnated with 100 parts by weight of a glass fiber substrate (thickness 0.18 mm, manufactured by Nitto Boseki Co., Ltd.). It was dried for about 5 minutes in a drying furnace to obtain a prepreg having a resin content of 50% by weight.

(3) Manufacture of laminated board 6 sheets of the above prepregs are stacked, copper foil is placed on the top and bottom, and copper foil (thickness 18 μm, Furukawa Circuit Foil) is placed on the top and bottom, and heated for 120 minutes at a pressure of 4 MPa and temperature of 180 ° C Pressure molding was performed to obtain a double-sided copper clad laminate having a thickness of 1.2 mm.
The above prepreg is placed on the upper and lower surfaces of the inner core material (35μ copper foil double-sided copper-clad blackened product, Nippon Auto Giken Co., Ltd.), and copper foil (thickness 18μm, Furukawa Circuit Foil) is placed on the top and bottom. Then, heat-pressure molding was performed at a pressure of 4 MPa and a temperature of 180 ° C. for 120 minutes to obtain a double-sided copper-clad multilayer board having a thickness of 1.0 mm.

(Example 2)
The resin component is 93.3 g of bisphenol A type epoxy resin, 42.9 g of cresol novolac type epoxy resin, the curing agent component is 2.2 g of dicyandiamide, 3.3 g of 4,4′-diaminodiphenylsulfone, and 2-phenyl-4-methylimidazole. 0.15 g was blended, 46 g of dimethylformamide was added thereto, and a resin varnish was prepared so that the solid content of the resin varnish was 56% by weight. Thereafter, a prepreg and a laminate were obtained in the same manner as in Example 1.

(Example 3)
113.3 g of bisphenol A type epoxy resin as resin component, 21.4 g of cresol novolac type epoxy resin, 1.9 g of dicyandiamide, 0.7 g of 4,4′-diaminodiphenylsulfone, and 2-phenyl-4-methylimidazole as curing agent components 0.15 g was blended, 46 g of dimethylformamide was added thereto, and a resin varnish was prepared so that the solid content of the resin varnish was 56% by weight. Thereafter, a prepreg and a laminate were obtained in the same manner as in Example 1.

(Comparative Example 1)
As a resin component, 113.3 g of bisphenol A type epoxy resin, 21.4 g of cresol novolac type epoxy resin, 2.3 g of dicyandiamide and 0.15 g of 2-phenyl-4-methylimidazole as a curing agent component were added, and 46 g of dimethylformamide was added thereto. The resin varnish was prepared so that the solid content of the resin varnish would be 56% by weight. Thereafter, a prepreg and a laminate were obtained in the same manner as in Example 1.

(Comparative Example 2)
As the resin component, 113.3 g of bisphenol A type epoxy resin, 21.4 g of cresol novolac type epoxy resin, 1.9 g of dicyandiamide as the curing agent component, 2.4 g of methylenebis (2-ethyl-6-methylaniline), 2-phenyl-4 -A resin varnish was prepared by adding 0.15 g of methylimidazole and 46 g of dimethylformamide so that the solid content of the resin varnish was 56% by weight.
Thereafter, a prepreg and a laminate were obtained in the same manner as in Example 1.

  Evaluation shown below was performed about the prepreg and the laminated board obtained by each Example and the comparative example. The obtained results are shown in Table 1.

1. Raw material (1) Bisphenol A type epoxy resin: manufactured by Japan Epoxy Resin Co., Ltd. “Epicoat 5047B75” epoxy equivalent 565
(2) Cresol novolac-type epoxy resin: manufactured by Dainippon Ink Co., Ltd. “Epiclon N690
70M ", epoxy equivalent 210
(3) Dicyandiamide: Ihara Chemical Industry Co., Ltd. (4) 2-Phenyl-4-methylimidazole: Shikoku Kasei Co., Ltd. (5) Methylenebis (2-ethyl-6-methylaniline): Ihara Chemical Industry Co., Ltd. -MED "

2. Evaluation Method (1) Preservability of Prepreg Using a prepreg, the curing time was measured according to JIS C 6481. The gel time immediately after preparation of the prepreg and after storage for 60 days at 20 ° C. and 35% RH was measured, and the percentage of the gel time (second) after storage relative to the gel time (second) immediately after preparation was calculated. It shows that preservability is so good that the value of a gel time residual rate is large. The gel time after storage was within ± 15%, and the others were x.

(2) Solder heat resistance A solder heat resistance test was performed in accordance with JIS C 6481 using a copper-clad laminate that had been etched on both sides. In the measurement, after performing a moisture absorption treatment for 2 hours after boiling, a sample was floated in a solder bath at 260 ° C. for 120 seconds, and the presence or absence of the appearance was examined. An item having no abnormality such as blistering or peeling was defined as “no abnormality”.

(3) Inner layer peel strength The adhesion between the inner layer circuit of the double-sided copper clad multilayer board and the outer insulating layer was measured according to JIS C6481.

(4) Glass transition point (Tg)
A copper-clad laminate that was etched on both sides was measured in accordance with JIS C6481 DMA method.

Examples 1 to 3 use the resin composition of the present invention in which bisphenol A type epoxy resin and cresol novolac type epoxy resin are blended as resin components, and dicyandiamide and 4,4′-diaminodiphenylsulfone are blended as curing agent components, and this is used. Prepreg and laminate.
In each of Examples 1 to 3, the prepreg was excellent in storability, and the laminated board had good moisture-absorbing solder heat resistance and peel strength. Particularly in Examples 1 and 2, since the blending amount of dicyandiamide and 4,4′-diaminodiphenylsulfone was optimal, the heat resistance was particularly excellent.
On the other hand, in Comparative Example 1, only dicyandiamide was used as the curing agent component, but both heat resistance and adhesion were inferior to those of the Examples. In Comparative Example 2, dicyandiamide and methylenebis (2-ethyl-6-methylaniline) were used as the curing agent components, but the storage stability of the prepreg was lowered.

  The present invention uses a resin composition characterized by containing bisphenol A type epoxy resin and cresol novolac type epoxy resin as resin components, and dicyandiamide and 4,4′-diaminodiphenylsulfone as curing agent components, and the same. It is a prepreg and a laminate, and can provide a laminate having improved storability in a prepreg state, a high glass transition point, and excellent adhesion and heat resistance.

Claims (9)

A resin composition comprising bisphenol A type epoxy resin and cresol novolac type epoxy resin as a resin component, and dicyandiamide and 4,4'-diaminodiphenyl sulfone as a curing agent component. Furthermore, the resin composition of Claim 1 containing a hardening accelerator. The resin composition according to claim 2, wherein the curing accelerator is an imidazole compound. The resin composition according to any one of claims 1 to 3, comprising 70 to 90% by weight of a bisphenol A type epoxy resin and 10 to 30% by weight of a cresol novolac type epoxy resin with respect to the entire resin component. The resin composition according to any one of claims 1 to 4, wherein a content of the dicyandiamide is 0.3 to 0.45 equivalent to an epoxy group of the resin component. The resin composition according to any one of claims 1 to 5, wherein a content of the 4,4'-diaminodiphenyl sulfone is 0.05 to 0.3 equivalents relative to an epoxy group of the resin component. The resin composition according to any one of claims 3 to 6, wherein the content of the imidazole is 0.1 to 0.2% by weight based on the entire resin component. A prepreg comprising the resin composition according to any one of claims 1 to 7 supported on a sheet-like fiber base material. A laminate obtained by heating and pressing the prepreg according to claim 6.