JP3410174B2 - Conductive resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

This invention relates to a water-soluble conductive resin composition.

[0002]

[Technical Background] Conventionally, as a material which obtains conductivity by drying at room temperature, a conductive paint or conductive adhesive using a metal powder such as silver or copper and an acrylic resin capable of drying at room temperature as a binder has been commercially available. ing. However, these conductive paints or conductive adhesives use an organic solvent in order to dissolve the acrylic resin or the like as a binder,
Due to the effects of organic solvents on the human body, it was necessary to pay sufficient attention to the work environment.

[0003]

SUMMARY OF THE INVENTION Under the above circumstances, it is an object of the present invention to provide a conductive resin composition which uses a binder whose solvent is water and is friendly to the working environment.

[0004]

In order to solve the above-mentioned problems, the present invention is based on 100 parts by weight of metal powder, an acrylic emulsion using polyester polyol as an emulsifier as a hinder (solid) 12 parts by weight or more 20 In the composition, 0.1 parts by weight or more and 2 parts by weight or less of a metal salt of a water-soluble saturated fatty acid or unsaturated fatty acid is kneaded as a dispersant.

Here, as the metal powder, gold powder, silver powder, silver-plated copper powder and the like can be used. Also,
These shapes may be any shape such as flakes, resin, spheres, and irregular shapes, and the particle size thereof is preferably 100 μm or less, particularly preferably 1 to 30 μm.

Here, the acrylic emulsion is prepared.
Time, the use of anionic emulsifiers commonly used metal powder
Fast settling, precipitated metal powder to form a hard cake
Re-distributed Te can not be used as a paint becomes difficult. Also, acrylic emulsions that use anionic emulsifiers are neutralized with amine-based materials in the emulsion neutralization process, so when used in combination with silver-plated copper powder, the residue of amine-based materials causes silver-plated copper powder to remain. This is not preferable because the copper in Example 2 is dissolved and the copper is ionized.

The metal salts of saturated fatty acids include sodium or potassium salts of lauric acid, myristic acid, etc., which are soluble in cold water. Examples of the metal salt of unsaturated fatty acid include sodium or potassium salts of oleic acid and linoleic acid. The use of these dispersants is preferable because it promotes fine dispersion of the metal powder in the acrylic emulsion and forms a coating film having good conductivity.

[0008]

The conductive resin composition of the present invention constructed as described above is an acrylic emulsion using polyester polyol as an emulsifier as a binder, and when the blending amount thereof is less than 12 parts by weight, it binds metal powder. Deteriorates and the resistance increases, and the adhesiveness also decreases. Also, 20
If it exceeds the weight part, the amount of metal powder for imparting conductivity becomes insufficient and the resistance becomes high.

If the amount of the saturated fatty acid or unsaturated fatty acid metal salt is less than 0.1 parts by weight, the dispersion of the metal powder becomes insufficient and the resistance becomes high. Further, even if added in excess of 2 parts by weight, the effect of improving the conductivity cannot be obtained, and the adhesiveness with the adherend decreases.

Within the scope of the present invention, a sufficient effect of preventing settling of metal powder can be obtained and a good conductive resin composition can be obtained. However, for the purpose of preventing settling of metal powder, a plate-like or rod-like powder, For example, if talc, whisker of potassium titanate or the like is added, the effect is further improved.

[0011]

EXAMPLES Examples 1 to 6 and Comparative Examples 1 to 4 were produced with the compositions shown in Table 1, and various tests were carried out on them. The results are shown in the lower column of Table 1. Details of kneading the composition and various tests are as follows.

[0012]

[Table 1] * 1 Aron NS-1200: Polyester resin as emulsifier
Acrylic emulsion using liol , trade name by Toagosei Kagaku Co., Ltd. * 2 Aron A-160: Acrylic emulsion with an emulsifier anionic and neutralized with amine, trade name by Toagosei Kagaku Co., Ltd.

[0013]

[Kneading of composition] After weighing each composition into an appropriate container,
The resin composition was stirred for 10 minutes with a stirrer.

[0014]

[Method of measuring specific resistance (conductivity)] A glass epoxy substrate was coated with the resin composition in a width of 2 mm and a length of 60 mm using a doctor blade, and then left to dry at room temperature for 10 minutes.
The resistance value and the thickness of the resin composition having a length of 60 mm after drying were measured to determine the specific resistance.

[0015]

〔Evaluation criteria〕

◯: The coating film does not peel off. X: The coating film is easily peeled off.

[0016]

〔Evaluation criteria〕

◯: The metal powder does not settle even after 24 hours have passed, and after standing for 1 week, the precipitated metal powder can be easily re-stirred. X: All the metal powder settles within 1 hour, and it is difficult to disperse the metal powder by stirring again.

[0017]

〔Evaluation criteria〕

Good: No blue precipitate is generated even after one week. X: A blue precipitate is generated in less than 3 hours.

From the above test results, it can be understood that each of the examples can be sufficiently used as a conductive resin composition. On the other hand, Comparative Example 1 has 2 acrylic emulsions.
Since it exceeds 0 parts by weight and the dispersant also exceeds 2 parts by weight,
Poor conductivity (specific resistance) and poor adhesion. In Comparative Example 2, since the acrylic emulsion is less than 12 parts by weight, the adhesion is poor. In Comparative Examples 3 and 4, the acrylic emulsions are anionic and neutralized with amine, so there are problems with the sedimentation of metal powder and the precipitation of blue. At this time, it can be understood from Comparative Example 4 that even if the titanium potassium whiskers were added, the sedimentation property / blue precipitation was not eliminated.

[0019]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, there is a problem of working environment when using a conductive resin composition which has been a problem in the conventional conductive resin composition using a resin binder containing an organic solvent. (Poisoning due to organic solvent) can be solved and the working environment can be significantly improved.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-247383 (JP, A) JP-A-1-167385 (JP, A) JP-A-2-105874 (JP, A) JP-A-3- 67402 (JP, A) JP-B 59-12682 (JP, B1) JP-B 60-33844 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 5/24 C09D 133 / 06 C09J 9/02 H01B 1/22

Claims (2)

(57) [Claims] 1. To 100 parts by weight of metal powder, 12 parts by weight or more and 20 parts by weight or less of an acrylic emulsion using polyester polyol as an emulsifier as a hinder, and a metal salt of a water-soluble saturated fatty acid or unsaturated fatty acid as a dispersant. A conductive resin composition obtained by kneading 0.1 part by weight or more and 2 parts by weight or less. 2. The conductive resin composition according to claim 1, wherein the metal powder is gold powder, silver powder or silver-plated copper powder, and the metal salt of the dispersant is sodium salt or potassium salt. .