JPH01297434A - Prepreg for laminated board - Google Patents

Abstract

PURPOSE:To provide a laminated board prepreg having excellent heat resistance and storage stability by coating and impregnating a resin composition comprising a specific epoxy resin, dicyandiamide and an imidazole derivative on and into a glass base material and subsequently drying the coated and impregnated resin composition. CONSTITUTION:A resin composition prepared by dissolving an epoxy resin (preferably a mixture system of a bisphenol A type epoxy resin and a novolak epoxy resin) containing 500-1200ppm of hydrolyzable chlorine, dicyandiamide and an imidazole derivative (e.g., 1-benzyl-2-methylimidazole) in an approximate amount of an organic solvent is coated on and impregnated into a glass base material and subsequently dried to perfectly cure the resin composition within a molding time, thereby providing a laminated board prepreg whose molding conditions are readily controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a resin composition for laminates and a 1-reg leg for laminates that have excellent heat resistance and storage stability.

(Prior Art) In recent years, the development of electronic technology has been remarkable, and copper-clad laminates have been used in a wide variety of ways, and those with advanced characteristics are being required. In particular, with the increasing density of wiring, the number of wiring layers is increasing, and the diameter of through holes for connecting between the eyebrows is becoming smaller, creating a demand for copper-clad laminates with good workability, such as less smearing during drilling. has been done. On the other hand, with the demand for improved productivity and lower costs, increasingly strict processing conditions are being added to the mounting process of wiring boards, such as hot air levelers and flow soldering. There is a growing demand for materials with better durability and moisture resistance than ever before.

The epoxy resin composition used for ordinary glass epoxy copper clad laminates contains bisphenol A epoxy resin or brominated bisphenol A epoxy resin, dicyandiamide as a curing agent, and a small amount of imidazole derivative as a curing accelerator. However, it is generally prepared by adding an appropriate amount of solvent. These epoxy resins contain 100 to 400 ppp of hydrolyzable chlorine to the resin solid fraction.
m, and therefore has high reactivity.
Furthermore, recently, epoxy resin compositions containing polyfunctional epoxy resins such as novolac epoxy resins and tetrafunctional epoxy resins have come into general use in order to improve heat resistance.

(Problem to be solved by the invention) However, when a polyfunctional epoxy resin is blended, the reactivity of the resin composition increases, the storage stability of the prepreg is poor, and it is difficult to control the molding conditions when manufacturing a laminate. was there. On the other hand, reducing the setting of curing acceleration in the resin composition and slowing down the reactivity of the resin improves the storage stability and moldability of the prepreg, but the resulting laminate is not completely cured within the limited molding time. However, there was a drawback that sufficient heat resistance could not be obtained.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a laminate that has excellent heat resistance and storage stability, is completely cured within the molding time, and can easily control molding conditions. The aim is to provide prepregs for

[Configuration of the Invention (Means for Solving the Problems) As a result of intensive research to achieve the above object, the inventor has determined that the amount of hydrolyzable chlorine is 500 to 12,001) l)I
The present invention has been completed based on the discovery that the above object can be achieved by using an epoxy resin containing the following.

That is, in the resin composition for a laminate of the present invention, the amount of hydrolyzable chlorine contained in the resin solid content is 500 to 1200 p.
It is characterized by having pn epoxy resin, dicyandiamide, and imidazole derivative as essential components,
Further, the prepreg for a laminate of the present invention is characterized in that it is formed by coating, impregnating, and drying this resin composition on a glass substrate.

The present invention will be explained in detail below.

As the epoxy resin used in the present invention, any compound having two or more epoxy groups in one molecule can be used. For example, glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak epoxy resin, or bromine compounds thereof, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resins, etc., and these may be used alone or in combination of two or more types, but among these, a mixed system of bisphenol A type epoxy resin and novolac epoxy resin is preferably used.

The amount of hydrolyzable chlorine in this epoxy resin solid content is 500
~1200 ppn. Hydrolyzable chlorine amount is 50
If it is less than 0 ppm, the reactivity of the resin composition will be high, the storage stability of the prepreg will be poor, and the control of molding conditions will be difficult, which is undesirable. If it exceeds 120(11)011, the reactivity of the resin composition will be too low. However, an excessive amount of imidazole derivative must be added as a curing accelerator, which is undesirable because heat resistance and moisture resistance decrease.

As the dicyandiamide used in the present invention, a wide variety of commonly commercially available dicyandiamides can be used, and there are no particular limitations.

As the imidazole derivative used in the present invention, for example, 1
-benzyl-2-methylimidazole, 2-ethyl-4
- Methylimidazole, 2-phenyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2-isoprobylimidazoles include cyanoethyl compounds, azine compounds, etc., which may be used alone or in combination of two or more. It can be used as

A resin composition can be produced by dissolving each of the above components, that is, a specific epoxy resin, dicyandiamide, and an imidazole derivative, in an appropriate amount of organic cuttings.

As the glass substrate used in the present invention, all glass substrates commonly used for laminates, such as glass cloth, glass nonwoven fabric, and glass paper, can be used.

A prepreg for a laminate can be produced by applying, impregnating and drying the resin composition produced in this way onto a base material by a conventional method. A copper-clad laminate can be obtained by stacking copper foil on at least one side of these Bripregs, heating, pressurizing, and integrally molding them.

(Function) The prepreg for laminates of the present invention comprises an epoxy resin with an amount of hydrolyzable chlorine in the resin solid content of 500 to 1200 ppn,
By using a resin composition containing dicyandiamide and an imidazole derivative as essential components, it was possible to obtain a resin composition with excellent heat resistance and storage stability. The hydrolyzable chlorine in the epoxy resin weakly combines with the tertiary amine of the imidazole derivative, resulting in a hydrolyzable chlorine amount of 500 to 12
It is thought that when 00 ppIl is present, the prepreg does not show activity at low temperatures, but shows activity as a curing accelerator at high temperatures during molding, promoting curing of the resin. Therefore, the prepreg has excellent storage stability, and the molded and cured prepreg has excellent heat resistance.

(Example) Next, the present invention will be specifically explained using Examples, but the present invention is not limited by the Examples. In the following Examples and Comparative Examples, "r parts" means "parts by weight". means.

Example The amount of hydrolyzable chlorine contained in the resin solid content is 600p
80 parts of bisphenol A type brominated epoxy resin (epoxy equivalent: 4800/EIQ) of p11, 20 parts of phenol novolak epoxy resin with a hydrolyzable chlorine content of 700 ppl in the resin solid molecule (the total amount of hydrolyzable chlorine in both epoxy resins is 640 ppH), 4 parts of dicyandiamide, 0.2 parts of 2-ethyl-4-methylimidazole, 40 parts of dimethylformamide and 80 parts of acetone were added and uniformly dissolved with stirring to prepare a resin composition. Next, a 180 μm glass nonwoven fabric was coated and impregnated with the resin composition, dried at a temperature of 160°C, and prepreg (A
) was manufactured.

Comparative Example 1 In the example, instead of both epoxy resins, the amount of hydrolyzable chlorine contained in the resin solid molecules was 200 ppIl.
Bisphenol A-type brominated epoxy resin (80 parts of Ji 460 (1/eq) per epoxy and 4001 parts of hydrolyzable chlorine in the resin solid content) pll of 20 parts of phenol novolac epoxy resin (total amount of hydrolysable chlorine is 2
A resin composition and a prepreg (B) were produced in the same manner as in the example except that 40 ppn) was used.

Comparative Example 2 In the example, instead of both epoxy resins, 80 parts of bisphenol A-type brominated epoxy resin with a hydrolyzable chlorine content of 2001) I) l contained in the resin solid content and the hydrolyzable content of the resin solid content were used. All examples are the same except that 20 parts of 7-technol novolac epoxy resin with a chlorine content of 400 ppl (the total amount of hydrolyzable chlorine is 240 ppn) and 0.06 part of 2-ethyl-4-methylimidazole were added. A resin composition and a prepreg for a laminate (C) were produced in the same manner as described above.

Comparative Example 3 In the example, ``instead of both epoxy resins, the amount of hydrolyzable chlorine contained in the resin solid content was 1500 pp+i
80 parts of bisphenol A type brominated epoxy resin and 20 parts of phenol novolak resin with a hydrolyzable chlorine content of 700 ppn in the resin solid content (the total amount of hydrolyzable chlorine is 13
A resin composition and a prepreg for a laminate (D) were produced in the same manner as in Example except that 0.5 part of 2-ethyl-4-methylimidazole was added.

Prepreg (A) manufactured in Examples and Comparative Examples 1 to 3
~(D) 4 sheets and 2 sheets of 70 μl thick copper foil were stacked together and heated and pressed together at a temperature of 170°C and a pressure of 40k (+/l') for 90 minutes to form a copper foil with a plate thickness of Q and 911. A clad laminate was manufactured. After forming an inner layer circuit on these copper clad laminates, two sheets of the prepreg described above were stacked on each of the front and back sides, and one sheet of copper foil with a thickness of 18 μl was placed on the top and bottom surfaces. A 4-layer board was manufactured by stacking each of the prepregs and 4-layer board.The obtained prepreg and 4-layer board were tested for quality, and the results are shown in Table 1. The results were excellent, confirming the effects of the present invention.

*1: Hydrolyzable chlorine amount measurement was performed using an epoxy resin sample at 0. After refluxing in IN-KOH methanol solution for 30 minutes, it was titrated with silver nitrate solution.

*2: A sample with the outer layer copper foil removed by etching was measured using a Percoll hardness meter (Model 934-1) on a hot plate at 130°C.

Ne3: After stacking three 4-layer board samples and drilling 5000 holes using a 0.9 nm diameter drill, calculate the average length of the smear generated in the inner copper foil layer (70 μl) as a percentage. expressed.

*4: Regarding the sample with the outer layer copper foil removed by etching,
PC71 After processing for 3 hours at 21°C and 2 atmospheres, the test pieces were rated 26 (0 if no flakes were formed when immersed in a 1°C solder bath for 30 seconds, and rated X if they were.

[Effects of the Invention] As is clear from the above explanation and Table 1, the prepreg for laminates of the present invention has excellent heat resistance and storage stability, is completely cured within the molding time, and is resistant to molding conditions. It can also be easily managed.

Claims (1)

[Claims] 1. The amount of hydrolyzable chlorine contained in the resin solid content is 500
~1200ppm epoxy resin, dicyandiamide,
A prepreg for a laminate, characterized in that it is made by coating, impregnating, and drying a glass substrate with a resin composition containing an imidazole derivative as an essential component. 2 The amount of hydrolyzable chlorine contained in the resin solid content is 500
~1200ppm epoxy resin, dicyandiamide,
A resin composition for a laminate, characterized in that it contains an imidazole derivative as an essential component.