JPH01149836A - Production of prepreg for heat-resistant laminated board - Google Patents

Abstract

PURPOSE:To obtain the title prepreg having excellent heat-resistance and moisture-resistance, etc., by coating and impregnating a substrate with a resin composition containing an addition reaction product of specific unsaturated dicarboxylic acid N,N'-bisimide compound, aminophenol and aromatic diamine and drying the impregnated product. CONSTITUTION:The objective prepreg having excellent storage stability, etc., and useful for the production of printed circuit board, etc., is produced by (1) coating and impregnating a substrate with a resin composition containing an addition reaction product obtained by compounding (A) an unsaturated dicarboxylic acid N,N'-bisimide compound of formula I (R1 is >=2C bivalent group; R2 is bivalent group containing C-C double bond), (B) an aminophenol of formula II (R3 is H, halogen, etc.) and (C) an aromatic diamine of formula III (R4-R7 are alkyl) at a ratio of 0.1-1.0mol of B+C per 1mol of the component A and heating the mixture and (2) drying the impregnated product.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for producing a heat-resistant laminate prepreg having excellent heat resistance, moisture resistance, and storage stability.

(Prior Art) In recent years, the development of electronic devices has been remarkable, and copper-clad laminates have been used in a wide variety of ways, and excellent characteristics are required. In particular, with the increase in wiring density, wiring boards are becoming more multi-layered and through-holes are becoming smaller in diameter, so there is a demand for copper-clad laminates with good workability, such as less smearing during drilling.

On the other hand, with the demand for improved productivity and lower costs, increasingly strict processing conditions are being added to the wiring board mounting process, such as hot air levelers and flow soldering. Among these, copper-clad laminates serving as substrates are required to have better heat resistance and moisture resistance than ever before.

In order to meet these demands, addition reaction type polyimide resins have recently come to be used instead of epoxy resins, which are generally widely used for copper-clad laminates. When this polyimide resin is used in prepreg for copper-clad laminates, the occurrence of smear during drilling becomes almost zero, and the heat resistance during processing and long-term tests is significantly improved.

However, conventionally used addition reaction type polyimide resins have had various problems as described below.

The product obtained by reacting the unsaturated dicarboxylic acid N,N'-bisimide with diaminodiphenylmethane is excellent for use in laminates, but on the other hand, diaminogenylmethane is highly reactive and is not suitable for use in varnishes and prepregs. There is a problem that the usage time is short.

Products containing N,N'-bisimide, an unsaturated dicarboxylic acid, and aminophenol as reaction components exhibit well-balanced properties and excellent processability for use in laminates, but have drawbacks in moisture resistance, such as For long-term storage of the obtained prepregs and laminates, special attention must be paid to moisture absorption. In addition, a product prepared by reacting N,N'-bisimide of an unsaturated dicarboxylic acid with aminobenzoic acid is suitable for use in laminates, but it has poor solubility in low boiling point solvents.
There were problems in that it was difficult to apply it to glass cloth, etc., and that care had to be taken in storing the resin solution.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned problems, and has improved heat resistance, moisture resistance, storage stability of resin solutions and prepregs, and solubility in low boiling point solvents. The present invention aims to provide an excellent method for producing prepreg for heat-resistant laminates that causes less smearing.

[Structure of the Invention] (Means for Solving the Problems) The method for producing a prepreg for heat-resistant laminates of the present invention is based on the following formula: (A) - Formula (wherein R1 has at least two carbon atoms a N,N'-bisimide compound of an unsaturated dicarboxylic acid represented by the formula (B) (where R3 is a divalent group containing a double bond between carbon atoms); (represents a hydrogen atom, a halogen atom or an alkyl group), an aromatic diamine represented by the formula (C) (wherein R4, R5, RG, and R7 represent the same or different alkyl groups) This method is characterized by coating a base material with a resin composition containing an addition reaction product as an essential component, impregnating the base material with the resin composition, and then drying the resin composition. Then, the addition reaction product is (B) aminophenol and (
The total amount of C) and the aromatic diamine [(B) + (C) is O51 to 1.0 mol.

The present invention will be explained below.

First, the N,N'-bisimide compound (A), the aminophenol (B), and the aromatic diamine (C) are reacted to obtain an addition reaction product, and then a resin composition is obtained using this as an essential component. (A) As the N,N'-bisimide compound of unsaturated dicarboxylic acid, one having the following general formula is used.

However, in the formula, R1 is 2 having at least 2 carbon atoms.
The valent group R2 represents a divalent group containing a double bond between carbon atoms. That is, R1 is a linear or branched alkylene group, a cycloalkylene group having a ring of 5 to 6 carbon atoms, a heterocyclic group containing at least one of oxygen, nitrogen, or sulfur atoms, and a benzene group. or polycyclic aromatic, -NHCO-, -NR" -+ -s i
Examples include multiple benzene groups and alicyclic groups bonded by R8R9- or -502-.

However, R8 and R9 represent an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having a ring having 5 to 6 carbon atoms, or a benzene group.

Further, R2, that is, a divalent group containing a double bond between carbon atoms, includes, for example, a maleic acid residue, a citraconic acid residue,
Examples include tetrahydrophthalic acid residues.

Therefore, as the N,N'-bisimide compound of unsaturated dicarboxylic acid that satisfies the above-mentioned conditions of R1 and R2,
Specifically, there are the following, and each of these can be used alone or in a mixed system of two or more. Maleic acid N, N'-4,4'-diphenylmethane bisimide, maleic acid 9N, N'-4,4'-diphenyl ether bisimide, maleic acid N, N'-paraphenylene bisimide, maleic acid N, N'- Benzidine bisimide, N maleic acid, N'-methaxylene bisimide, N maleic acid.

N'-1,5-naphthalene-bisimide, maleic acid N
.

N'-4,4'-diphenylsulfone-bisimide, N maleic acid, N'-2,2'-4,4'-dimethylene-cyclohexane-bisimide, N maleic acid, N'-
4゜4'-dicyclohexyl-methane bisimide, maleic acid N, N'-4,4'-diphenylcyclohexane-bisimide, maleic acid N, N'-4,4'-diphenyl-phenylamine-bisimide, maleic acid N
, N'-4,4'-diphenyl-diphenylsilane-
Bisimide, maleic acid N, N'-4,4'-diphenyl sulfur-bisimide, maleic acid N, N'-2,2
'-(4,4'-diphenyl)-propane-bisimide, N maleic acid, N'-metaphenylene-bisimide,
Examples include maleic acid N, N'-3,3'-(N, N'-metaphenylene-bisbenzamide) bisimide.

As the aminophenol (B) used in the present invention, one having the following general formula is used.

-9= However, in the formula, R3 represents a hydrogen atom, a halogen atom, or an alkyl group. Specific examples of these compounds include the following, which may be used alone or in combination of two or more. Examples include 0-aminophenol, l-aminophenol, p-aminophenol, 2-amino-4-talolophenol, and 2-amino-4-methylphenol.

As the aromatic diamine (C) used in the present invention, an aromatic diamine having the following general formula is used.

However, in the formula, R', R5, R6, and R' represent the same or different alkyl groups, and specific examples include 4,4'-diamino-3,3', 5,5'- Tetodipropyldiphenylmethane, 4,4'-diamino-3,
3'-diethyl-5,5'-dipropyldiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5
'-dimethyldiphenylmethane, 4,4'-diamino-
Examples include 3,3', 5,5'-tetraethyldiphenylmethane, which may be used alone or in combination of two or more.

An addition reaction product is produced by heat-reacting the aforementioned (A) N,N'-bisimide compound of unsaturated dicarboxylic acid, (B) aminophenol, and (C) aromatic diamine in a solvent-free or inert solvent.

The blending ratio of these three components is N of the unsaturated dicarboxylic acid,
It is desirable that the total amount of aminophenol and aromatic diamine be blended in a range of 0.1 to 1.0 mol per 1 mol of the N'-bisimide compound. If the proportion is less than 0.1 mol, the reaction will not proceed and properties such as heat resistance and toughness will deteriorate;
If the amount exceeds 0 mole, unreacted amine will remain and the heat resistance will drop significantly, which is not preferable. The order of blending the three components, the reaction temperature, and the solvent can be selected as appropriate and are not particularly limited.

Hereinafter, a typical manufacturing process will be explained as an example.

N,N'-bisimide compounds of unsaturated dicarboxylic acids, aminophenols, and aromatic diamines are charged into a reaction vessel in a predetermined ratio, and the contents are melted by heating to 100 to 200°C to achieve a predetermined viscosity and cure. Proceed with the reaction until the time is up.

This reaction product is acetone.

A resin solution having properties suitable for a laminate can be produced by dissolving it in a solvent such as methyl ethyl getone, dioxane, tetrahydrofuran, or dimethyl formamide (DMF). It is also possible to use a solvent from the beginning. For example, an N,N'-bisimide compound of an unsaturated dicarboxylic acid, an aminophenol, and an aromatic diamine are charged together with dioxane into a reaction vessel, and the dioxane is refluxed to a predetermined viscosity and cure time, and then DMF, etc. By adding a solvent and cooling, a resin solution for a laminate can be produced.

The addition reaction product thus prepared can be made into a resin composition by blending various additives and fillers depending on the purpose. For example, a catalyst such as diagonal imidazole for adjusting the curing rate and a diagonal coupling agent for imparting adhesive properties can be blended. Further, a flame retardant and an inorganic filler that impart flame retardancy may be appropriately blended.

The resin composition produced as described above was coated and impregnated on a base material such as glass cloth or glass nonwoven fabric, and then dried in a drying tower for 10 minutes.
It can be dried within a temperature range of 0 to 200°C to produce a prepreg for a heat-resistant laminate.

This prepreg is heated and pressed by a predetermined method and can be used for manufacturing a laminate, a copper-clad laminate, or a printed wiring board.

(Function) By using the specific diamine having the aforementioned latent properties as the aromatic diamine, the pot life of varnishes and prepregs is improved, and the solubility in low boiling point solvents is also improved. It also maintains the excellent processability characteristic of the addition reaction type, making it possible to produce prepregs with excellent heat resistance.

(Example) Next, the present invention will be specifically explained using examples.

Example 1 In a flask equipped with a stirrer and a thermometer, maleic acid N,
N'-4,4'-diphenylmethane bisimide 358
g, 45 g of 2-amino-4-di-tetraphenol, and 30 q of 4°4'-diamino-3,3'-dimethyl-5,5'-diethyldiphenylmethane were charged and heated while stirring. When the temperature exceeds 100℃, it gradually begins to dissolve,
It becomes a brown liquid. This liquid was heated to 120℃ and
Stir for hours. After complete addition reaction of aminophenol and aromatic diamine to bismaleimide in this manner, the mixture was dissolved in dioxane and DMF to make a 50% solution, and stirred to form a -like varnish. Next, a glass woven fabric having a thickness of 180 μm was coated and impregnated with the prepared varnish, and dried at a temperature of 160° C. to produce a prepreg having a resin content of 43% by weight. Using 4 sheets of this prepreg and 2 sheets of @ foil with a thickness of 70 μm, a temperature of 170°C and a pressure of 40 kg/cm'
A copper clad laminate with a thickness of 0.9 mm was produced by integrally molding the product under heat and pressure for 0 minutes.

After forming an inner layer circuit on this head laminate, two sheets of prepreg were stacked on each of the front and back sides, and one sheet of copper foil with a thickness of 18 μm was stacked on the top and bottom surfaces to create a four-layer board. The properties of the obtained four-layer board were tested and are shown in Table 1, and it was found to have excellent heat resistance and moisture resistance.
The effects of the present invention were confirmed. In addition, the prepreg was evaluated for its pot life during storage and was found to have good storage stability as shown in Table 1.

Example 2 Maleic acid N, N'-4,4'-diphenylmethane bisimide 358Q and O-amine phenol 16 g.
A varnish was prepared in the same manner as in Example 1 by charging 50 g of 4,4'diamino-3,3',5,5'-tetraethyldiphenylmethane into a flask. Using this varnish, a 1-repreg, 4-layer board was produced under the same conditions as in Example 1. We also tested the properties of the cord in the same way, and the results are shown in Table 1. It has excellent heat resistance and moisture resistance.
The effect of the present invention was confirmed.

The prepreg was also evaluated for pot life during storage, and as shown in Table 1, it was found to have good storage stability.

Example 3 358 g of maleic acid N, N'-4,4'-diphenylmethane bisimide and 45 (l) of m-aminophenol and 4,4'-diamino-3,3'-diethyl-5,5'
A varnish was produced in the same manner as in Example 1 by charging 30 liters of -dipropyldiphenylmethane into a flask. Using this varnish, a prepreg and a four-layer board were produced under the same conditions as in Example 1. Also, in the same manner as in Example 1. The results are shown in Table 1, and the heat resistance and moisture resistance were excellent, confirming the effects of the present invention.

The prepreg was also evaluated for pot life during storage, and as shown in Table 1, it was found to have good storage stability.

Comparative Example 1 358 g of maleic acid N, N'-4,4'-diphenylmethane bisimide, m-amine phenol 45 Q, and p-aminobenzoic acid ethyl ester, 11 () were placed in a flask and treated in the same manner as in Example 1. Manufactured varnish.

Using this varnish, a prepreg and 4-layer board was prepared under all the same conditions as in Example 1. In addition, the characteristics of the wires were tested in the same manner, and the results are shown in Table 1.

Comparative Example 2 Malein ilN, N'-4,4'-diphenylmethane bisimide 358Q, m-aminophenol 33 g, and 4,4'-diaminodiphenylmethane 35 g were charged into a flask, and a varnish was produced in the same manner as in Example 1. did.

Using this varnish, a prepreg and four-layer board was made under the same conditions as in Example 1. In addition, the properties of the fibers were tested in the same manner, and the results are shown in Table 1.

Table 1 *1: Measured by JII S-6481.

*2: Measurement of the peel strength between the inner silver foil treated with copper oxide and the prepreg layer.

*3: Measured using a Percoll hardness tester (Model 934-1) on a sample with the outer silver foil removed by etching.

*4: Measure the number of hits until smear occurs on the inner layer silver foil when two 4-layer board samples are stacked and holes are drilled using a 0.9n+m diameter drill.

*5: A sample with copper foil cut into 25×25111ffl was floated in a solder bath at 300° C. for 20 minutes, and the state of the bag was evaluated.

○ mark: Good, no bags are formed. × mark: Bags are formed.
T After processing at 121°C and 2 atm for 5 hours, the condition of the bag was evaluated when it was immersed in a 260°C solder bath for 30 seconds.

○ mark: good, no flakes = 19 - x mark: flakes occur [Effects of the invention] As is clear from the above explanation and Table 1, the heat-resistant laminate prepreg of the present invention According to the manufacturing method, a prepreg with excellent heat resistance, moisture resistance, storage stability of resin solutions and prepregs, and solubility in low boiling point solvents and less smear generation can be obtained.

Claims (1)

[Claims] 1 (A) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, in the formula, R^1 is a divalent group having at least 2 carbon atoms, and R^2 is a carbon atom. N, N' of an unsaturated dicarboxylic acid represented by (representing a divalent group containing a double bond between)
- Bisimide compound, (B) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, R^3 represents a hydrogen atom, a halogen atom or an alkyl group), (C) General formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R^4, R^5, R^6, R^7 represent the same or different alkyl groups), an addition reaction consisting of an aromatic diamine, 1. A method for producing a prepreg for a heat-resistant laminate, which comprises applying and impregnating a resin composition, which has a resin composition as an essential component, onto a base material and then drying the resin composition. 2 The addition reaction product is the total amount of aminophenol (B) and aromatic diamine (C) [(B) + (C)] per mol of N,N'-bisimide compound (A). 0.1
The method for producing a prepreg for a heat-resistant laminate according to claim 1, wherein the amount is blended by 1.0 mol.