JPS6090253A - Electrically-conductive material - Google Patents

Abstract

PURPOSE:The titled material having improved molding properties and electrical conductivity, softening at low temperature, obtained by reacting a specific polyoxyalkylene glycol with a polyfunctional carboxylic acid or its anhydride, or its lower alkyl ester to give a specified high-molecular-weight compound, blending this compound with an electrically-conductive filler. CONSTITUTION:A polyoxyalkylene glycol having >=8,000 average molecular weight and >=70wt% ethylene oxide unit content and a polyfunctional carboxylic acid (e.g., malonic acid, succinic acid), its anhydride or its lower alkyl ester (e.g., monomethyl ester, etc.) are blended in equivalent amounts calculated as functional group ratio in esterification or ester exchange reaction, and the blend is reacted at 120-250 deg.C at 10<-4>-10Torr to give a high-molecular-weight compound having >=50,000 average molecular weight, and 100pts.wt. high-molecular- weight compound is blended with 10-200pts.wt. electrically-conductive filler (gold, silver, nickel, etc.).

Description

[Detailed description of the invention] The present invention relates to electrically conductive materials.

Various conductive materials have been announced in the past, including polymeric materials containing conductive fillers and materials whose resin itself is conductive, such as antistatic materials, power cables, surface heating elements,
It is used in many applications such as conductive paint, electromagnetic shielding material, and electroplating. Note that conductivity as used herein means a property with a resistivity of 1080·am or less.

However, the conductive particles conventionally used as described above have drawbacks such as a high softening point and a lack of suitable solvents. Therefore, when used in the manufacture of expensive products, it is extremely difficult to remove the conductive particles once the wrong operation is performed, and the products to which they are applied usually become unusable. Put it away. Even if the conductive material used by mistake can be removed using an organic solvent or the like, it is difficult to control the workability and the low temperature to prevent fire occurrence.

In view of this situation, the present inventors have conducted extensive research to find a repairable conductive material that does not have the above-mentioned drawbacks, and has found that the average molecular grave is 8000 or more and the ethylene oxide unit content is 70% ( % by weight, the same applies hereinafter) or more
Excellent films or sheets are produced by blending a conductive filler with a high molecular weight compound with an average molecular weight of 50,000 or more prepared by reacting lyoxyalkylene gellicol with a polyhydric carboxylic acid, its anhydride, or its lower alkyl ester. We discovered that it is possible to obtain a conductive material that has formation ability, softens at low temperatures, is water bathable, and has excellent conductivity.
The present invention has now been completed.

In the present invention, the average molecular weight of
A polymer compound with a molecular weight of more than 100 ml is produced.

It is preferable that the POAG has an average molecular weight of 8000 or more and an ore containing ethylene oxide units of 70% or more. When the molecular weight is less than 8,000, the solvent solubility and film-forming ability of the polymer compound produced using it tend to be insufficient, and therefore the film properties of the conductive material produced using the polymer compound, especially the physical properties, tend to be insufficient. There also tends to be a lack of strength. On the other hand, when the ethylene oxide unit content of POAG becomes less than 70%, f'O
When a high molecular weight compound is produced by reacting AG with a polyhydric carboxylic acid, its anhydride, or its lower alkyl ester, the condensation reaction tends to be slow and the reaction time becomes long, and it is insoluble in water. It may become difficult to solidify at room temperature due to the lowering of the melting point.

The POA () can be obtained by addition polymerizing an alkylene oxide containing ethylene oxide to a compound having two active hydrogen atoms.

Examples of the active hydrogen group include a hydroxyl group of water or alcohol, an amine 7 group, a phenolic hydroxyl group, and the like. Specific examples of the compound having two active hydrogen groups (hereinafter referred to as starting material) include water, ethylene glycol, diethylene glycol, tetrapyrene glycol, dibbed pyrene glycol, 1,4-butanediol, 1,6
-hexanediol, neopentyl glycol, bisphenol A1 polyethylene glycol, polytetramethylene glycol, polypropylene glycol, methylamine, ethylamine, propylamine, aniline-1-butylamine-1-octylamine, laurylamine, cyclohexylamine, and the like.

As the alkylene oxide used for addition polymerization, ethyleneoxy F is used as an essential component in an amount of about 70% or more,
In addition, propylene oxide, butylene oxide, styrene oxide, etc. are used in less than about 60% of the combined H1 type. When copolymerizing the alkylene oxides, block copolymerization, random copolymerization, or a combination of these may be copolymerized. Preferably.

Such addition polymerization is carried out using a conventional method, using a caustic alkali such as sodium hydroxide or potassium hydroxide as a catalyst,
It is carried out for about 2 to 60 hours at a humidity of about 90 to 200°0.

In the present invention, the polyhydric carboxylic acid, its anhydride, or its lower alkyl ester to be reacted with the FOAG includes, for example, (a) malonic acid, succinic acid, maleic acid, 77/I/acid, adipic acid, cepacic acid. , phthalic acid, isophthalic acid,
Terephthalic acid, itaconic acid, trimellidic acid, pyromellitic acid or dimer acid, (b) monomethyl ester, dimethyl ester, monoethyl ester, diethyl ester, seven-knob pyl ester, dipropyl ester, monobutyl ester or dibutyl of (a) Examples include esters or (a) acid anhydrides of the acids listed in (a).

The polymeric mineral compound used in the present invention can be converted into the polymeric mineral compound used in the present invention by reacting the PQAG with a polycarboxylic acid, its anhydride, or lower alkyl ester. For example, the polymer ash compound used in the present invention can be changed by reacting the PQAG with a polyhydric carboxylic acid, its anhydride, or its lower alkyl ester under ester-like conditions.

The average molecular weight of the high molecular weight compound is preferably 5oooo or more. When the molecular weight is less than 50,000, the conductive material of the present invention manufactured using the high molecular weight compound has low mechanical strength and becomes brittle.

Examples of the conductive filler used in the present invention include gold,
Examples include powders, flakes, whiskers, fibers, etc. manufactured from metals such as silver, nickel, copper, iron, aluminum, and zinc, and carbon-based powders and fibers such as acetylene black, 7-arnes black, graphite, and carbon fiber. . These conductive fillers are selected and used in terms of conductivity, cost, appearance, etc.

The ratio of the conductive filler to 100 parts (animal parts, hereinafter the same) of the high molecular weight compound is preferably 10 to 200 parts, and is determined depending on the type of filler.

The polymer ash compound and the conductive filler may be mixed by a conventional method, such as kneading with rolls or a Banbury mixer.
This can be done by methods such as. For example, as a method using a roll, a method in which the conductive filler is gradually added to a high molecular weight compound heated to about 60 to 120° C. while kneading is preferred.

The conductive material of the present invention has good conductivity and has a temperature of about 70°C.
Since it can be handled at relatively low temperatures of about 100 mL or higher and uses a water-soluble high molecular weight compound as the base resin, it can be wiped off at low temperatures or washed off with water or steam. Furthermore, when a coal-based powder is used as a conductive filler, the conductive material has a
It exhibits good conductivity at temperatures below 70°C (conductivity with a resistance value of about 10 to 10 Ω・am with 60 parts of acetylene black), and has a resistance of about 6
When the temperature exceeds 0 to 70°0, the resistance value increases significantly due to the so-called PTO effect, so that it can function as a thermostat.

Since the electroconductive material of the present invention has the above characteristics, it can be used in surface heating elements, antistatic materials, thermal sensors, conductors, etc. It can be used in a wide range of applications such as paints.

Next, the conductive material of the present invention will be explained based on Examples.

Production Example 1 106 parts of diethylene glycol and 20 parts of flaked caustic potassium were placed in an autoclave, and 120 parts of ethylene oxide was heated at 160°C at a rate of 2 kg/am2・G or less.
The reaction was carried out while gradually adding 00 parts.

The weight average molecular weight of the product (intermediate) was determined by measuring the hydroxyl value and alkali value and was found to be approximately 10,000.

1.9 parts of dimethyl terephthalate per 100 parts of the product obtained.
After adding 4 parts and raising the temperature to 200°C, I Torr
The mixture was heated under reduced pressure for 6 hours while removing methanol to obtain a high molecular weight compound.

The obtained high molecular weight compound had a mass average molecular weight (measured by high-performance liquid lithography) of about 200,000. Further, when 5 parts of the compound were added to 95 parts of water and the solubility was examined, it was found that it was completely dissolved.◇Production side 2 to 6 The products (intermediates) shown in Table 1 were obtained in the same manner as in Production Example 1. A molecular weight compound was obtained.

Examples 1 to 10 The conductive filler shown in Table 2 was kneaded into 100 parts of the polymeric electrical compound obtained in the production example using a heating roll at 80°0,
Obtained conductive material.

Using the obtained conductive material at 80°o, 400°C
0n'', heat pressed for 3 minutes, thickness 0.1mm, length 10cm
A conductive film with a width of 5 am and a width of 5 am was obtained.

The tensile strength, elongation, tear strength, electrical resistance, softening point, and solubility of the obtained film were measured based on the following methods. The results are shown in Table 2. Tensile strength, elongation and tear strength are
Measured according to J Engineering 5x-6601 and :rxs K-6760. The electrical resistance was measured by crimping copper foil onto the diagonal ends of the rectangle and using a resistance meter. Softening point is J engineering 5x
-7206. The solubility is determined by the thickness of 0.
A 1 mm film piece 19 was placed in a container containing about 50 ml of water.
It was measured whether the polymeric magnetic compound dissolved within 30 seconds by dropping it into a 00ml beaker, and it was judged as good if it dissolved within 60 seconds and only the filler settled.

In Table 2, Denka Black was acetylene black granules manufactured by Denki Kagaku Kogyo Ilso, and silver powder, gold powder, and graphite were reagents.

Claims (1)

[Claims] 1. An average molecule prepared by reacting a polyoxyalkylene glycol with an average molecular weight of 8,000 or more and an ethylene oxide unit content of 70% by weight or more and a polyhydric carboxylic acid, its anhydride, or its lower alkyl ester. An electrically conductive material characterized by blending a conductive filler with a polymer compound of 50,000 or more.