JP2007154029A - Polyamide-imide resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a material having high heat-resistance and excellent mechanical strength and thermal dimensional stability and suitable as a flexible circuit board, endless belt for printer and copying machine and separator for non-aqueous secondary battery and electric double layer capacitor. <P>SOLUTION: The problem is solved by using naphthalenediamine (diisocyanate) as an essential component and substituting a part of preferably trimellitic anhydride of acid component with 3,3',4,4'-benzophenonetetracarboxylic acid anhydride and/or 3,3',4,4'-biphenyltetracarboxylic acid anhydride. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel polyamideimide resin. In particular, heat resistance, mechanical strength, thermal expansion coefficient is small and excellent in thermal dimensional stability, flexible printed circuit board, insulating substrate for TAB, multilayer printed circuit board, seamless belt for printer, porous membrane for lithium ion secondary battery separator The present invention relates to a polyamide-imide resin useful for such as

Currently, polyimide resins having excellent heat resistance and mechanical strength are widely applied to insulating films for flexible printed circuit boards. However, since polyimide resin does not dissolve in a solvent, it must be heated and closed at a high temperature of 400 ° C or higher after film formation in the state of polyamic acid, which is a precursor, and refrigerated storage is necessary because polyamic acid is unstable. There were problems such as. On the other hand, polyamideimide resin is excellent in storage stability because it is dissolved in a polar solvent such as N-methyl-2-pyrrolidone, and is excellent in productivity because it can be dried at a temperature of 300 ° C. or less, but is inferior in heat resistance and thermal dimensional stability. Therefore, its use was limited.
However, in recent years, with the advancement of electronics and information industry, and the reduction in size and weight, circuit boards and printer transfer belts with excellent thermal dimensional stability can be used as heat resistant resins with high heat resistance, excellent dimensional stability and good productivity. The demand is getting stronger.

  The present invention improves the above-mentioned drawbacks of polyamide-imide resin, and provides a resin that is excellent in heat resistance, thermal dimensional stability and mechanical strength, and useful for circuit board insulating substrates, seamless belts for printers, and heat-resistant porous membranes. With the goal.

  As a result of intensive studies to achieve the above object, the present inventor has reached the present invention. That is, the present invention relates to a polyamide-imide resin containing a naphthalene skeleton in an amine residue, having a glass transition temperature of 350 ° C. or higher, a thermal expansion coefficient of 30 ppm or less, and a tensile elastic modulus of 4500 MPa or more.

  The present invention introduces a rigid naphthalene structure into a resin skeleton, thereby improving heat resistance and toughness, reducing the thermal expansion coefficient, and a flexible printed circuit board suitable for high-density wiring, and a printer with excellent dimensional stability. Materials useful for fixing belts, intermediate transfer belts and heat-resistant separators for lithium ion secondary batteries can be provided.

The present invention will be described in detail below.
In general, the polyamideimide resin can be easily synthesized by stirring trimellitic acid chloride or anhydride and diamine or diisocyanate in a polar organic solvent such as N-methyl-2-pyrrolidone at room temperature or under heating.

  Although the acid component used for the synthesis of the polyamideimide resin of the present invention is mainly trimellitic anhydride, a part thereof can be replaced with other polybasic acid or anhydride thereof. For example, tetracarboxylic acids such as pyromellitic acid, biphenyl tetracarboxylic acid, biphenyl sulfone tetracarboxylic acid, benzophenone tetracarboxylic acid, biphenyl ether tetracarboxylic acid, ethylene glycol anhydrobis trimellitate, propylene glycol anhydro bis trimellitate and the like This is accomplished by copolymerizing the anhydrides. Among these, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic acid anhydride are preferable in terms of reactivity, heat resistance, dimensional stability, and the like. Things are preferred.

  The ratio of trimellitic anhydride to 3,3 ′, 4,4′-benzophenonetetracarboxylic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic anhydride is trimellitic anhydride Preferably, the product is in the range of 50 to 80 mol%, benzophenone tetracarboxylic anhydride is 10 to 40 mol%, and 3,3 ', 4,4'-biphenyltetracarboxylic anhydride is 0 to 30 mol%. Trimellitic anhydride is 50 mol% or less, 3,3 ′, 4,4′-benzophenone tetracarboxylic anhydride is 40 mol% or more, 3,3 ′, 4,4′-biphenyltetracarboxylic anhydride is If it is 30 mol% or more, the heat resistance is improved, but the thermal expansion coefficient is rather lowered, or the solvent solubility is lowered and the moldability is deteriorated. Further, when the trimellitic anhydride is 80 mol% or more, heat resistance and dimensional stability are insufficient for this purpose.

  In addition, oxalic acid, adipic acid, malonic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, dicarboxypolybutadiene, dicarboxypoly (acrylonitrile-butadiene), dicarboxypoly, as long as the properties of the polyamideimide resin of the present invention are not impaired. Aliphatic dicarboxylic acids such as (styrene-butadiene), 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 4,4′-dicyclohexylmethanedicarboxylic acid, alicyclic dicarboxylic acids such as dimer acid, terephthalic acid And aromatic dicarboxylic acids such as isophthalic acid, diphenylsulfone dicarboxylic acid, diphenyl ether dicarboxylic acid and naphthalenedicarboxylic acid. Among these, dimer acid and acrylonitrile butadiene dicarboxylic acid are preferable from the viewpoint of adhesion to various base materials and solvent solubility.

  In addition, a urethane group can be introduced into the molecule by replacing part of the acid component with glycol. Examples of glycols include alkylene glycols such as ethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, and hexanediol, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, and one or more of the above dicarboxylic acids. And a terminal hydroxyl group polyester synthesized from one or more of the above-mentioned glycols. Among these, polyethylene glycol and a terminal hydroxyl group polyester are preferable in terms of adhesion to a substrate and solvent solubility. . Moreover, these number average molecular weights are preferably 500 or more, and more preferably 1000 or more. The upper limit is not particularly limited, but is preferably less than 8000.

Naphthalenediamine (diisocyanate) is essential for the diamine (diisocyanate) component used in the synthesis of the polyamideimide resin of the present invention. However, aliphatic diamines such as ethylenediamine, propylenediamine, and hexamethylenediamine and alicyclic rings such as these diisocyanates, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and dicyclohexylmethanediamine, as long as the object of the present invention is not impaired. Diamines and their diisocyanates, m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, benzidine, 3,3′-dimethyl Examples thereof include aromatic diamines such as benzidine and xylylenediamine, and diisocyanates thereof. Among these, diaminodiphenylmethane, 3,3′-dimethylbenzidine, and the like in terms of reactivity, cost, and solvent solubility. Isophorone diamine, dicyclohexylmethane diamines and these diisocyanates are preferred.
Diamine (diisocyanate) other than naphthalenediamine (diisocyanate) is 50 mol% or less, preferably 30 mol% or less of the total. If it is 50 mol% or more, the heat resistance and dimensional stability are lowered.

  The polyimide resin used in the present invention is heated at room temperature or 60 to 200 ° C. in a polar solvent such as N, N′-dimethylformamide, N, N′-dimethylacetamide, N-methyl-2-pyrrolidone, and γ-butyrolactone. It can be easily produced by stirring while stirring. In this case, amines such as triethylamine and diethylenetriamine, alkali metal salts such as sodium fluoride, potassium fluoride, cesium fluoride, sodium methoxide, and the like can be used as a catalyst as necessary.

The polyamide-imide resin with the naphthalene structure of the present invention is based on its rigid structure, and exhibits a high glass transition temperature and a low coefficient of thermal expansion compared to conventional polyamide-imide resins, greatly improving heat resistance and dimensional stability. ing.
Therefore, the polyamide-imide resin of the present invention is wet from the polyamide-imide resin solution, the seamless belt molded from the solution in which the conductive material is mixed with the polyamide-imide resin as the insulating material of the high-density wiring board, and from the polyamide-imide resin solution. The porous film obtained by film formation is a suitable material for lithium ion secondary batteries, heat-resistant separators for capacitors, and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited by these Examples.
In addition, the measured value in an Example was measured with the following method.

(1) Logarithmic viscosity A solution obtained by dissolving a polyamideimide resin solution in water, coagulating it, thoroughly washing it and then drying it at 70 ° C. for 10 hours or more in 100 ml of N-methyl-2-pyrrolidone at room temperature. It measured in a 30 degreeC thermostat using an Ubbelohde viscosity tube.
(2) Tensile strength and elongation A resin solution is applied on a polyester film, dried at 100 ° C for 10 minutes, then peeled off, fixed to a metal frame, and further dried at 250 ° C for 1 hour to obtain a Toyo Boldwin film. Measurement was performed at a pulling speed of 20 mm / min using a Tensilon of the company.
(3) Glass transition temperature Loss elasticity measured using a dynamic viscoelasticity measuring device DVA-220 manufactured by IT Measurement Control Co., Ltd. at a heating rate of 5 ° C./min and a frequency of 110 Hz. The inflection point of the rate was taken as the glass transition temperature.
(4) Thermal expansion coefficient Dimensional change rate between 100 ° C. and 200 ° C. when the film used for measuring tensile strength and elongation was measured at a temperature rising rate of 5 ° C./min using a thermomechanical property measuring device Thermoflex manufactured by Rigaku Corporation. Was the coefficient of thermal expansion.
(5) Water absorption rate About 1 g of the film used in the tensile test was immersed in water at 25 ° C. for 24 hours, and then water on the surface was wiped off and precisely weighed with an electronic balance. (W1) Next, the same sample is dried with a hot air dryer at 120 ° C. for 1 hour, left in a desiccator for 30 minutes, and then weighed again. (W0) The water absorption was obtained from the following equation.
Water absorption (%) = 100 × (W1-W0) / W1
(6) Film thickness It measured using the micrometer made from SONY.
(7) Gloss Gloss checker (IG-320) manufactured by Horiba Seisakusho was directly pressed against the surface of the endless belt.
(8) Surface resistance The endless belt was cut into 15 cm square and measured at room temperature using Yokogawa Hewlett Packard's HIGH R EISTANCE METER.
(9) MIT
Using a measuring device compliant with JIS C5016, an endless belt having a width of 10 mm was measured under the conditions of a weight of 1 kg and a tip R = 0.38 mm, and the number of flexing until breaking was obtained.
(10) Air Permeability A porous film of about 5 cm □ was measured at room temperature using a tester industry air permeability measuring device.

[Example 1]
Trimellitic anhydride (TMA) 0.7 mol, 3,3 ′, 4,4′-benzophenone tetracarboxylic anhydride (BTDA) 0.3 mol in a flask equipped with a condenser, nitrogen gas inlet tube and stirrer , 1 mol of naphthalene diisocyanate (NDI) and 0.01 mol of diazabicycloundecene (DBU) were charged together with N-methyl-2-pyrrolidone (NMP) to a solid content concentration of 15%, and at 80 ° C. for about 3 hours. Reacted. The properties of the obtained polyamideimide resin are shown in Table 1.

[Example 2]
In Example 1, 0.7 mol of TMA, 0.2 mol of BTDA, 3,3 ′, 4,4′-biphenyltetracarboxylic anhydride (BPDA) 0.1 mol, 1 mol of NDI, 0.01 mol of BDU Polymerization was carried out under the same conditions as in Example 1 except that. The properties of the obtained polyamideimide resin are shown in Table 1.

[Example 3]
In Example 1, it polymerized on the same conditions as Example 1 except having set it as TMA0.6 mol, BTDA0.4 mol, NDI1 mol, DBU0.01 mol. The properties of the obtained polyamideimide resin are shown in Table 1.

[Example 4]
In Example 1, polymerization was performed under the same conditions as in Example 1 except that the diisocyanate component was 0.7 mol of NDI and 0.3 mol% of 3,3′-dimethyl-4,4 ′ diisocyanate dimethyl. The properties of the obtained polyamideimide resin are shown in Table 1.

[Example 5]
The polyamideimide resin solution of Example 1 was applied to a 1/2 oz rolled copper foil so that the film thickness was 12.5 μm, dried at 100 ° C. for 10 minutes, and then the polyamideimide resin surface was an outer layer on an aluminum tube having a diameter of 3 inches. And then dried at 280 ° C. for 30 minutes. The obtained copper-clad laminate has no curl, adhesion is 1.2 kg / cm, and it is not peeled or swollen even when immersed in a solder bath at 300 ° C. for 1 minute. The shrinkage after the treatment was 0.004%, which was excellent in dimensional stability.

[Example 6]
100 parts of the polyamideimide resin solution of Example 2 and 5 parts of carbon black (Conductex SC from Colombian Carbon) were mixed and kneaded with a three-roll mill, and the solution was sprayed into an aluminum cylindrical mold. The belt was dried and rotated at 150 ° C. for 30 minutes and further at 280 ° C. for 1 hour, and then peeled from the mold to obtain a belt having a thickness of 90 μm. This belt has excellent mechanical durability of 550 times, gloss is 125%, surface resistance is 5.3 × 1011 Ω / □, and the surface is smooth, producing transfer belts for printers and copiers with excellent electrical characteristics. did it.

[Example 7]
A solution obtained by blending 10 parts of polyethylene glycol having a molecular weight of 400 with 100 parts of the polyamideimide resin solution of Example 2 was applied onto a 100 μm polyester film with an applicator having a gap of 50 μm, and immersed in an aqueous solution with 20% NMP at room temperature for 1 minute. The polyester film was peeled off, washed with water and dried at room temperature. The obtained porous film has a porosity of 65%, an air permeability of 122 seconds, and the appearance hardly changes even when immersed in a propylene carbonate bath at room temperature for 20 hours, and is a lithium ion secondary battery or a non-aqueous electric double layer capacitor. It was suitable for the separator.

[Comparative Example 1]
A polyamideimide resin was synthesized under the same conditions as in Example 1 except that 1 mol of trimellitic anhydride and 1 mol of diphenylmethane 4,4′-diisocyanate were used in Example 1. The properties of the obtained polyamideimide resin are shown in Table 1.

[Comparative Example 2]
Polymerization was carried out under the same conditions as in Example 1 except that the acid component of Example 1 was changed to 0.3 mol of TMA and 0.7 mol of BTDA. As the polymerization progressed, the solution became cloudy and did not dissolve in NMP.

[Comparative Example 3]
A copper-clad laminate was prepared using the polyamideimide resin of Comparative Example 1 under the same conditions as in Example 5. However, the curl was strong and the shrinkage after etching at 150 ° C. for 30 minutes was 0.12%. High dimensional stability was insufficient.

[Comparative Example 4]
An endless belt was prepared in the same manner as in Example 6 using the polyamideimide resin of Comparative Example 1. The belt had a MIT of 122 times, and its durability was poor and practical use was difficult.

  The polyamide-imide resin of the present invention is excellent in mechanical properties, electrical properties, heat resistance, and dimensional stability. Therefore, the insulating base material for flexible circuit boards, endless belts for printers and copying machines, non-aqueous secondary batteries, and electric double layer capacitors. Useful materials can be provided for porous membranes.

Claims (5)

  A polyamide-imide resin containing a naphthalene skeleton in an amine residue, having a glass transition temperature of 350 ° C. or more, a thermal expansion coefficient of 30 ppm or less, and a tensile elastic modulus of 4500 MPa or more.   Acid component is trimellitic acid 50-80 mol%, 3,3 ', 4,4'-biphenyltetracarboxylic acid 0-30 mol%, 3,3', 4,4'-benzophenone tetracarboxylic acid 10-40 mol The solvent-soluble polyamideimide resin according to claim 1, comprising:   A circuit board using the polyamide-imide resin according to claim 1.   A seamless belt using the polyamide-imide resin according to claim 1.   A porous film using the polyamide-imide resin according to claim 1.