JP2938227B2 - Polyamic acid resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamic acid resin particularly suitable for a flexible printed circuit board, and more particularly to two or three aromatic tetracarboxylic dianhydrides and three or more aromatic tetracarboxylic dianhydrides. and the family diamine component
Polyamic acid flexible printed board was reacted
It is about resin .

[0002]

2. Description of the Related Art Polyimide is widely known as a high heat-resistant polymer, but has a drawback in moldability due to its rigid molecular skeleton. Further, with the recent development of the electronics and electric industries, a flexible printed circuit board that can be mounted three-dimensionally is widely used as a mounting method for communication and consumer devices. Currently, a polyimide film is widely used for the flexible printed circuit board. In this case, the performance required for the polyimide film, such as heat resistance, adhesive strength with the metal foil, coincidence of the coefficient of thermal expansion with the metal foil,
There is electrical insulation. Various polyimides have been developed so far, but those with excellent heat resistance have poor adhesion to metal, while those with excellent adhesion have a larger coefficient of thermal expansion than metal foil, There were drawbacks such as occurrence.

[0003]

DISCLOSURE OF THE INVENTION The present invention was obtained as a result of a study aimed at obtaining a polyimide resin having excellent heat resistance and adhesion to a metal foil and having a coefficient of thermal expansion close to that of the metal foil. Things.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method for producing a 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride (hereinafter abbreviated as BPDA) as an essential component, and 3,3 ', 4,4'
-Benzophenonetetracarboxylic dianhydride (hereinafter BT)
DA) and / or bis (3,4-dicarboxyphenyl) ether dianhydride (hereinafter abbreviated as ODPA)
A carboxylic acid dianhydride component containing 0 to 50 mol% , and
p-phenylenediamine (hereinafter abbreviated as PPD)
General formula (I) containing 60 mol%

[0005]

Embedded image

An aromatic diamine component having a molar ratio of an aromatic diamine represented by the following formula and 1,3-bis (3-aminophenoxy) benzene (hereinafter abbreviated as APB) of 70:30 to 90:10 is The present invention relates to a polyamic acid resin reacted at a molar ratio of an acid component to a diamine component of 0.9 to 1.1.

[0007]

The polyamic acid solution used in the present invention comprises N-methyl-2-pyrrolidone, (hereinafter abbreviated as NMP), dimethylacetamide, dimethylformamide,
It can be obtained by stirring an aromatic carboxylic dianhydride component and an aromatic diamine component in a solvent such as cresol. The molar ratio of the aromatic carboxylic dianhydride component to the aromatic diamine component is preferably from 0.90 to 1.10, and more preferably from 0.97 to 0.99. If the molar ratio between the acid component and the amine component is outside the above range, the molecular weight of the resulting polyimide will be small, and the physical properties of the product will be reduced. In particular, when heat resistance is taken into consideration, it is desirable to react with an excess of the diamine component.

The acid component used in the polyamic acid of the present invention includes BPDA, BTDA, ODPA and the like. The molar content of BPDA is preferably at least 50 mol% in the acid component, particularly preferably 70 to 80 mol%.
The molar ratio between BTDA and ODPA is from 100: 0 to 0:10
Although it can be used arbitrarily in the range of 0, 90:10
~ 50: 50 is preferred, particularly preferably 80: 20 ~
70:30. The resin synthesized using BPDA as an essential component can further improve the adhesiveness by forming a copolymer with BTDA and ODPA.

The aromatic diamine represented by the general formula (I) includes p-phenylenediamine, m-phenylenediamine (hereinafter abbreviated as MPD), and 2,4-tolylenediamine (hereinafter abbreviated as 2,4-TDA). ), 1,4-dimethyl-
2,5-diaminobenzene (hereinafter abbreviated as 25PDX) and the like. Aromatic diamine represented by general formula (I) and A
The molar ratio of PB is 70: 30 to 90: 10. AP
By adding B in this range, the adhesive strength can be improved. When the addition amount of APB is 30 mol%, the adhesive strength is improved, but the heat resistance is reduced and the coefficient of thermal expansion is increased. Among the aromatic diamines represented by the general formula (I), the amount of p-phenylenediamine to be added is 20 to 60 % by mole of the total amount of the diamine components , preferably 30 to 60 %.
60 mol%. As the amount of PPD increases, the heat resistance of the polyimide film increases, and the value of the coefficient of thermal expansion decreases. On the other hand, the adhesive strength decreases.

A printed circuit board can be obtained by applying the boramic acid resin of the present invention to a metal foil such as a copper foil or an aluminum foil and drying and curing the metal foil. Further, it is also possible to impregnate a substrate such as a glass cloth into a prepreg. The drying temperature of the resin applied to these substrates is usually 80 to 380 ° C.
A printed circuit board can be obtained by heating for up to 180 minutes.

The polyamic acid resin of the present invention can be used for bonding metal and plastic such as polyimide.
It is also excellent in bonding metal and plastic. In addition, since it is excellent in heat resistance, a double-sided board can be obtained by laminating two polyimide layers of a flexible printed circuit board composed of a polyimide having no adhesive layer and a metal foil. . Further, a double-sided flexible printed circuit board can be obtained by bonding together copper foils. It can also be used as an adhesive for a high heat resistant film cover coat.

[0012]

【Example】

(Example 1) PPD was used as a four-necked lascohediamine component equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux condenser tube
3.24 g (0.03 mol), 25 DPX 8.17 g
(0.06 mol), 2.94 g (0.01 mol) of APB
Was added, and 100 g of NMP was added, and the mixture was sufficiently stirred at room temperature under a nitrogen stream to dissolve the diamine component. Next, BP
20.18 g (0.07 mol) of DA, 9.47 BTDA
g (0.03 mol) was gradually added, and 75 g of NMP was added, followed by stirring at room temperature for 4 hours. 75 g of ethanol was added thereto, and the mixture was further stirred for 1 hour. Reduced viscosity of the resulting solution (0.5 g of resin dissolved in 100 ml of NMP, 30 ° C
Was measured in a thermostat) and the resin content was 15% by weight. This resin solution has a thickness of 25 μm after drying.
Is applied on a copper foil of 35 μm thickness so that
After drying at 350 ° C. for 1 hour for 1 hour, a flexible substrate was obtained.

Example 2 As a diamine component, PPD was used.
5.31 g (0.05 mol), 4.33 g of MPD (0.3%).
04 mol), 2.92 g (0.01 mol) of APB, 20.18 g (0.07 mol) of BPDA as an acid component, O
Using 9.12 g (0.03 mol) of DPA, a flexible substrate was obtained by the same apparatus and method as in Example 1.

[0014]

Comparative Example 1 As a diamine component, 25D
6.81 g (0.05 mol) of PX, 14.62 g of APB
(0.05 mol), BPDA 20.18 as an acid component
g (0.07 mol) and 9.47 g (0.03 mol) of BTDA, a flexible substrate was obtained by the same apparatus and method as in Example 1.

Comparative Example 2 PPD was used as a diamine component.
7.57 g (0.07 mol), 3.67 g of 24TDA
(0.03 mol), BTDA22.56 as an acid component
g (0.07 mol) and 9.12 g (0.03 mol) of ODPA, a flexible substrate was obtained by the same apparatus and method as in Example 1.

[0017] While the embodiment 1, 2 及 Beauty Comparative Example results obtained were evaluated flexible substrate and the film at 1 and 2 are shown in Table 1. The flexible substrate using the resin of the example exhibited excellent values balanced with the peel strength and the coefficient of thermal expansion as compared with the comparative example.

[0018]

[Table 1]

[0019]

The polyimide resin obtained according to the present invention is excellent in heat resistance and adhesiveness to a metal foil, and has a coefficient of thermal expansion close to that of a metal foil. By using this, a flexible substrate excellent in adhesiveness, dimensional stability and heat resistance can be obtained as compared with a conventional polyimide resin. It is also useful as a prepreg impregnating resin or a film cover coat adhesive.

Claims (1)

(57) [Claims] 1. A method comprising: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as an essential component;
20 to 60 mol of a carboxylic acid dianhydride component containing 0 to 50 mol% of 4'-benzophenone tetracarboxylic dianhydride and / or bis (3,4-dicarboxyphenyl) ether dianhydride , and p-phenylenediamine %
General formula (I) containing The molar ratio of the aromatic diamine represented by the formula : 1,3-bis (3-aminophenoxy) benzene is 70:30 to 9
A polyamic acid resin obtained by reacting an aromatic diamine component having a ratio of 0:10 with a molar ratio of an acid component to a diamine component of 0.9 to 1.1.