JPH0611860B2 - Heat resistant flexible resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an aromatic polyamide-imide resin composition which is used in many fields such as electronic materials, paints and films having both heat resistance and flexibility.

[Conventional technology and its problems]

In recent years, the development of electronics has been remarkable, and the demand for miniaturization and high functionality, as seen in lightness, thinness, shortness, and size reduction, has led to stronger demands for new characteristics and functions for material parts, coupled with the development of new applications.

In particular, the emergence of a material having both heat and humidity dimensional stability and flexibility is strongly desired in the field.

Under such circumstances, there is a polyimide resin typified by Kapton as a material that has both heat resistance and flexibility.
However, polyimide resins must have excellent electrical properties, mechanical properties, heat resistance and flexibility, but they have problems in dimensional stability during heat and humidity, and they are easy to process and easy to use. It is a resin material that needs improvement.

In addition, a solvent-soluble polyamide-imide resin has been proposed in order to improve the processability and usability of this polyimide resin. (See, for example, Japanese Examined Patent Publication No. 49-35076) However, it is true that it has heat resistance and flexibility in terms of basic physical properties such as a thermal decomposition starting temperature or a glass transition point, but it is practical. However, when a flexible printed circuit board is used, the warpage is large, and swelling or dimensional shrinkage occurs during heat resistance of the solder. Furthermore, when used as an overcoat of a wiring board, the resin still has many problems in practice, such as swelling, wrinkles, and peeling during heat-resistant soldering (300 ° C, 10 seconds). Is the current situation.

Although a method of adding an inorganic filler to an aromatic polyamide-imide resin has been proposed (see Japanese Patent Publication No. 57-26700), this improves heat resistance but loses flexibility and adhesiveness of the liver and kidneys. The problem is that

Thus, it has heat and humidity dimensional stability and flexibility, and is easy to process.
Despite the strong needs for materials that are easy to use, the reality is that they have not yet been realized.

[Problems to be solved by the invention]

The problems to be solved by the present invention are the problems that the above-mentioned conventional techniques have, and the object of the present invention is to have the heat and humidity dimensional stability and flexibility which are strongly demanded at present. Moreover, it is to provide a material that can be processed by a simple method such as printing or coating.

[Means for solving problems]

This object is the general formula of the invention (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a methylene group, and n represents an integer of 2 or more), and a polar organic solvent-soluble aromatic polyamideimide resin and gold, silver, platinum, Copper, nickel, aluminum, molybdenum, silicon, cobalt, tungsten,
A heat-resistant flexible resin having a specific resistance value of 10 ⁷ Ωcm or more in which 1 to 35% by volume of a conductive metal fine powder selected from iron, titanium, zinc, alloys thereof and mixtures thereof is blended. Achieved by the composition.

Common sense is that the metal powder used for imparting conductivity can be used as a component of an “insulating material” that has good heat and humidity dimensional stability, has flexibility, and has good processability. It's amazing.

Hereinafter, the present invention will be described in detail.

The aromatic polyamide-imide resin used in the present invention is a polar organic solvent-soluble aromatic polyamide-imide resin having the general formula (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group or a methylene group, and n represents an integer of 2 or more), or a mixture thereof.

The reduced viscosity of the aromatic polyamideimide resin used in the present invention is not particularly limited as long as it is 0.5 or more, but it is practical that the solution viscosity at the time of use is up to about 3.5. If the reduced viscosity is too low, the mechanical strength and flexibility will decrease, and if the reduced viscosity is too high, the solubility in polar organic solvents will decrease, making it impractical.

These aromatic polyamide-imide resins are known methods,
For example, it can be produced by reacting an aromatic diamine with trimellitic anhydride chloride or by reacting an aromatic diisocyanate with a bisimide dicarboxylic acid.

The reaction among them will be described below as a typical example.

The aromatic diamine (X in the formula has the same meaning as described above) and trimellitic anhydride chloride are reacted in a polar organic solvent such as N, N-dimethylacetamide or N-methyl-2-pyrrolidone.

Examples of the aromatic diamine (A) include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminodiphenyl sulfone,
Mention may be made of 4,4'-diaminobenzophenone and 4,4'-diaminodiphenylmethane.

These aromatic diamines (A) are preferable because they have excellent flexibility, heat resistance, and moisture resistance as compared with m-phenylenediamine.

Examples of the polar organic solvent of the aromatic polyamideimide resin of the present invention include N, N-diethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, hexamethylphosphoramide, halogenated cresol or Examples thereof include mixed solvents thereof, or mixed solvents of these and other conventional solvents.

The conductive metal fine powder used in the present invention is gold, silver, platinum, copper,
It is preferably selected from nickel, aluminum, silicon, molybdenum, iron, cobalt, tungsten, titanium, zinc and alloys thereof and mixtures thereof.

The shape is not particularly limited, and any shape can be used, but a layered or flaky shape is particularly preferable.

The particle size is not particularly limited as long as it is a so-called fine powder, but usually 50 μm or less is preferable. When used in the form of a film, it is desirable to select a particle size up to 1/2 of the film thickness.

The blending ratio of the conductive metal fine powder is 1 to 35% by volume, preferably 5 to 25% by volume.

This blending ratio is important, and if the blending ratio of the conductive metal fine powder is too high, it becomes impossible to satisfy the requirement that the specific resistance value is 10 ⁷ Ωcm or more, which is one of the essential requirements of the present invention. That is, it must be avoided because it becomes a conductor instead of an insulator or semiconductor.

By the way, according to the analysis of electric conductivity of the conductive polymer composite material (Industrial Materials, Vol. 23, No. 11, pp. 85-91 (1975)), the conductive mechanism is that the formation of the path by the contact of the conductive filler. It is considered to be the main one.

Therefore, it is necessary to keep the amount of metal powders such that they do not come into contact with each other to form an insulator or a semiconductor, which is 35% by volume or less in the present invention, as described above. is there.

Also, in order to impart insulation (semi-conductivity) suitable for the intended use, the optimum blending amount changes depending on the shape and particle size (size) of the metal powder. It is recommended that the relationship between the value and the bending resistance and the blending ratio be preliminarily obtained by experiments and the blending amount be determined based on this.

If the blending ratio is too high, mechanical strength and flexibility are reduced in terms of physical properties, which is also undesirable from this point of view.

On the other hand, if the blending ratio is too low, the dimensional stability at the time of heat and humidity, which is another feature of the present invention, will be problematic, so it must be avoided.

In summary, when the content of the conductive metal fine powder is out of the range of the present invention, the semiconductivity or insulation of the liver and kidney is lost, or when the film or flexible copper clad substrate is used,
In the 00 ° -20 second solder immersion test, blistering, warping, etc. are generated, and warping due to moisture absorption is also generated, which impairs dimensional stability during heat and humidity.

The composition of the present invention is prepared by adding 230 to 9900 parts by weight of the above polar organic solvent that substantially dissolves the aromatic polyamideimide resin to 100 parts by weight of the aromatic polyamideimide resin, and adding conductive metal fine powder to this mixture. Can be used in a uniformly dispersed form. This solvent-containing composition is suitable for use as a paint or adhesive.

As a method for producing the composition containing the solvent of the present invention, a conventionally known method can be used. For example, it is produced by adding an aromatic polyamide-imide resin to a polar organic solvent, completely dissolving it, and then adding a conductive metal fine powder, and uniformly dispersing it with a kneader, a ball meal, a three-roll mill or the like. be able to.

The heat-resistant flexible resin composition is obtained by evaporating the solvent from the composition to which the solvent is added by ordinary heating, vacuum heating, heating with far infrared rays or the like, or removing the solvent by another method.

If desired, various additives may be added to the composition of the present invention. One example is adding a silane coupling agent, glass powder, glass fiber, heat-resistant fiber, or the like in order to enhance the adhesiveness or mechanical strength.

(Effects of the invention) As described above, the heat-resistant flexible resin composition of the present invention is extremely excellent in heat resistance and moisture resistance, and has good adhesiveness,
It has mechanical strength and electrical characteristics, and has excellent flexibility and workability.

The composition of the present invention is suitable for use in materials for electronic parts, particularly flexible printed boards, and also for other materials for electronic parts, such as heat and humidity resistant films, sheets, paints, inks, adhesives, etc. You can It can also be widely applied as a general heat resistant material.

(Example) Next, the present invention will be described with reference to Examples and Comparative Examples.

The measured values shown in the following examples are obtained by the following measuring method and apparatus.

Specific resistance value (insulating property) Conducted according to JIS K6911. The thickness of the test piece is 15
It was set to 0 μm.

Tensile strength Using Tensilon tensile tester manufactured by Toyo Baldwin,
A test piece having a width of 6 mm and a thickness of 100 μ was measured at a tensile distance of 50 mm and a tensile speed of 10 mm / min.

Folding resistance was performed according to JIS P8115.

Using a MIT tester, a test piece having a width of 15 mm and a thickness of 50 μ was measured at R = 0.38 and a tension of 0.5 kg.

Moisture permeability Measured according to JIS Z0208.

A test piece having a thickness of 0.1 mm was measured by the cup method under the conditions of 40 ° C. and 90% RH.

Solder heat resistance (curl degree) A test piece was immersed in solder at 300 ° C for 20 seconds, then pulled up and cooled to room temperature, and the curl degree was measured by the following method.

A 1-inch wide test piece is placed on a flat surface. Next, measure the maximum distance between the curved surface of the test piece and the plane reference surface in mm,
This was defined as the curl degree.

Adhesiveness It measured by the cross cut-tape method.

A coating film having a thickness of 50 mm is formed and used as a test piece. After cross-cutting this test piece according to the JIS K400 cross cut test, attach PET tape and then peel it off to 10
The number of remaining squares in 0 squares was counted.

Example 1 4,4'-Diaminodiphenyl ether (DADPE)
Aromatic Polyamide-imide (P) soluble in polar organic solvent synthesized from and trimellitic anhydride chloride (TMAC)
AI; reduced viscosity 1.5) 120 parts by weight of N-methyl-2
-Adding 480 parts by weight of pyrrolidone (NMP),
Dissolve. Then aluminum powder (average particle size 15μ
A solution in which 54 parts by weight of Fukuda Metal Foil Industry Co., Ltd. ALC fine) was dispersed in 108 parts by weight of N-methyl-2-pyrrolidone (NMP) was mixed with the PAI resin solution,
After premixing with a kneader, the mixture was passed through three rolls to obtain a paste-like resin composition in which aluminum powder was uniformly dispersed.
This resin composition is PAI 80% by volume Al powder 20% by volume
Consists of.

The paste composition was cast on a siliconized glass substrate and dried by touch in a temperature range of 90 ° C to 130 ° C.
Then, it is peeled from the glass substrate to obtain a film-like material. The film-like material is sandwiched between sandwiching jigs and heat-treated at 200 ° C. to 300 ° C. until the solvent is completely evaporated.

These heat treatment times are slightly different depending on the thickness of the sample necessary for measuring the following physical properties, but for example, for a film-like composition having a thickness of 100 μm, 90 ° C. and 130 ° C. for 1 hour each, 200 ° C., 250 ° C. and 300 ° C. It was processed for 20 minutes.

80% by volume of PAI and Al powder 2 thus obtained
Physical properties of a film-shaped heat-resistant resin composition consisting of 0% by volume were measured by the above-mentioned measuring methods. Fixed resistance value: 4.2 × 10 ¹² Ω · cm Moisture vapor transmission rate: 3.0 gr / cm ² · 24 Hr / 100 μm Tensile strength: 11.5 kg / mm ² , which was excellent in insulation, strength and moisture resistance.

Similarly, when a film having a thickness of 50 μm was prepared and subjected to a bending resistance test, it was found to be excellent in flexibility of 1000 times.

The film was subjected to a solder dipping test at 300 ° C. for 20 seconds, and the result was that the curl degree was 0.05 mm and the heat resistance was excellent.

Next, the paste composition was applied onto a copper foil having a thickness of 35 μm, the solvent was volatilized to form a dry coating film having a thickness of 40 μm, and the adhesiveness was tested by the cross-cut method to find that it was 100/100. It was excellent.

Also, this is treated at 40 ° C. and 90% RH for 10 hours to obtain 300
When a solder immersion test was performed at 20 ° C for 20 seconds, no peeling or blistering was observed.

Examples 2 to 11 and Comparative Examples 3 to 9 Film-like materials were obtained in the same manner as in Example 1 except that various PAIs were used and the type and amount of metal powder were changed, and various physical properties were measured. did.

The results are shown in Table 1.

Comparative Examples 1 and 2 Table 1 shows examples (Comparative Examples 1 and 2) in which no metal powder is added as comparative examples.

In addition, the manufacturing method and the measuring method of the film-like material of the comparative example are the same as those of the example.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-55-9642 (JP, A) JP-A-55-9643 (JP, A) JP-A-54-143462 (JP, A) JP-A-59- 8731 (JP, A) JP 57-162752 (JP, A) JP 59-9803 (JP, A) JP 58-53966 (JP, A) JP 55-127462 (JP, A) JP-A-58-79020 (JP, A) JP-B 44-6068 (JP, B1) JP-B 45-27994 (JP, B1) JP-B 46-9946 (JP, B1) JP-B 46-15513 (JP, B1) JP 58-11899 (JP, B2) JP 58-11456 (JP, B2)

Claims (1)

[Claims] 1. A general formula (However, X represents an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a methylene group, and n represents an integer of 2 or more), and a polar organic solvent-soluble aromatic polyamideimide resin represented by gold, silver, platinum, Copper, nickel, aluminum, molybdenum, silicon, cobalt, tungsten,
A heat-resistant flexible resin having a specific resistance value of 10 ⁷ Ωcm or more in which 1 to 35% by volume of a conductive metal fine powder selected from iron, titanium, zinc, alloys thereof and mixtures thereof is blended. Composition.