JPH0129043B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a resistive ink composition for producing resin-based resistors used in various electronic circuits.

Conventional Structure and Problems Resin-based resistors have been widely used as fixed resistors or variable resistors. These conventional resistors have used thermosetting resin as the binder resin, so manufacturing the resistor requires high temperatures and a long time, and furthermore, when laminated on a paper-phenol resin substrate, etc., the substrate etc. may deteriorate. It has the problem of
Improvement is desired.

OBJECTS OF THE INVENTION An object of the present invention is to provide a resistive ink composition for solving the above-mentioned problems associated with the production of conventional resin-based resistors. This object is achieved by manufacturing a resistor by irradiating the resistive ink composition described in detail below with an electron beam or rapidly heating it with a radiation type heating device.

Structure of the Invention The resistive ink composition according to the present invention uses an acrylic ester or methacrylic ester of a bisphenol A-formaldehyde condensate as a binder resin, or together with the above ester,
It is characterized by using a monomer or oligomer containing at least one acrylic group, methacrylic group, or allyl group, or a mixture thereof. Then, conventionally known conductive powder such as metal powder, carbon black, graphite, etc. is dispersed in these binder resins, and a solvent is added if necessary, and an ink prepared is applied onto the substrate, dried if necessary, and then By irradiating it with an electron beam or heating it for a short time using a radiation type heater, a resistor with excellent characteristics can be obtained in an extremely short time.

The bisphenol A-formaldehyde condensate described here refers to 1 mole of bisphenol A and 4
It is a product obtained by reacting molar formaldehyde in the presence of an alkali catalyst, and esters can be produced by reacting with acrylic acid, methacrylic acid, or their lower alcohol esters in a non-alcoholic solution.

The monomer or oligomer to be mixed with the above ester contains at least one acrylic group,
Those containing methacrylic or allyl groups can be used. Although these monomers or oligomers can be used alone, in many cases, it is easier to control the resistor characteristics when used in a mixed system. Examples of monomers or oligomers that can be used here include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, ethylene glycol diacrylate, trimethylolpropane triacrylate, Acrylic esters or oligoacrylates of primary or polyhydric alcohols such as pentaerythritol triacrylate, various epoxy acrylates, various oligoester acrylates, various urethane acrylates, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, methacrylic acid 2-
Methacrylic esters of primary or polyhydric alcohols such as ethylhexyl, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl alcohol, diallyl ether, diallyl adipate, diallyl phthalate,
Examples include arylates at both ends of low molecular weight polyurethane.

The mixing ratio of the acrylic acid or methacrylic acid ester solution of the bisphenol A-formaldehyde condensate and the above monomer or oligomer can be arbitrarily selected depending on the required characteristics of the resistor.

As the conductive powder to be dispersed in these resin compositions, conventionally known conductive powders can be used. Examples include metal powders such as silver, copper, or alloys thereof, metal oxide powders, metal carbide powders, metal nitride powders, metal boride powders, carbon black, graphite, or mixtures thereof. The mixing ratio of these conductive powders and the binder resin composition may be within a conventionally known range. The binder resin composition and the conductive powder are mixed and kneaded by a known method, adding a solvent if necessary.
The resistor is manufactured by coating the substrate on a substrate, drying it if necessary, and then irradiating it with an electron beam, or heating it with a radiation-type heating device immediately after coating.

The resistor obtained here is extremely hard and is particularly suitable as a resistor for a variable resistor that requires wear resistance.

Description of examples The present invention will be explained below with reference to Examples.

Example 1 (a) Bisphenol A-formaldehyde condensate acrylic ester solution Bisphenol was placed in a four-necked flask equipped with a thermometer, stirrer, reflux condenser, and dropping funnel.
Add 1 mol of A and 4.5 mol of 38% formalin, and add 2.2 mol of 6N caustic soda aqueous solution to 60 ml from the dropping funnel.
Add dropwise while making sure not to exceed ℃. After dropping, the reaction was carried out at 60±1°C for 2 hours, neutralized with 6N sulfuric acid aqueous solution, washed with water, and concentrated under reduced pressure to obtain 85% tetramethylolated bisphenol A.
Produce a solution. After adding 50 parts by weight of isophorone to 100 parts by weight of this solution, residual water is removed under reduced pressure. Then 70 parts by weight of acrylic acid containing 4000 ppm of hydroquinone and p-
Add 0.2 parts by weight of toluenesulfonic acid to 80±
After reacting at 1° C. for 1 hour, unreacted acrylic acid was removed under reduced pressure. Then, add ethanol to make a 60% solution.

(b) Resistance ink 50 g of the above solution, 15 g of fine carbon powder, and 30 g of butyl carbitol are mixed and kneaded in a three-roll mill to produce a resistance ink.

(c) Resistor After coating the above resistance ink on a paper-phenol resin substrate and drying it, a 165eV electron beam was applied.
A resistor was manufactured by irradiating 15 Mrad. The time required for electron beam irradiation was less than 0.1 seconds for a length of 15 cm. The resistor obtained here is approximately 0.5K
It had a sheet resistance value of Ω/□ and was hard with a pencil hardness of 8H. This resistor showed only -3.0% and 1.0% changes after 1000 hours of 85°C heat resistance test and 60°C/95% humidity resistance test, respectively. Furthermore, when this resistor was incorporated into a variable resistor and a sliding test was performed, no noise or other abnormalities were observed even after 30,000 sliding operations. For comparison, a heat resistance test and a moisture resistance test of a resistor using thermosetting resistance ink showed changes of -5.5% and 2.5%, respectively.

Example 2 In Example 1, 35 parts of acrylic acid was replaced with 70 parts of acrylic acid.
A resistor made using parts by weight of methacrylic acid without removing residual monomers has a sheet resistance of 0.7KΩ/□, a pencil hardness of 9H or higher, and -3.0% and -3.0% in heat resistance and moisture resistance tests, respectively. It showed a change of 1.0%.

Example 3 In Example 1, in addition to 50 g of the acrylic acid ester solution of the condensate, 3 g of trimethylolpropane trimethacrylate and epoxy acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) were used as the binder resin.
The resistor obtained when using 30g of product name Viscoat #540 and setting the amount of carbon fine powder to 30g is
It exhibited a pencil hardness of 7H with a resistance value of 0.6KΩ/□, and showed changes of -9.5% and -1.5% in the heat resistance and moisture resistance tests, respectively.

Example 4 In Example 3, in addition to 50 g of the acrylic ester solution of the condensate, 18 g of oligoester acrylate (manufactured by Toagosei Co., Ltd., trade name Aronix M-8030) and 6 g of hexanediol diacrylate were used as the binder resin. The resistor obtained in this case had a sheet resistance of 1KΩ/□, a pencil hardness of 9H, and - in heat resistance and moisture resistance tests, respectively.
It showed a change of 8.5% and 2.5%.

Example 5 In Example 1, the resistor obtained when 5 g of diethylene glycol dimethacrylate was added to 50 g of the condensate ester solution as the binder resin had a sheet resistance value of 0.5 KΩ/□ and a pencil hardness of 9H or more. Indicated. This resistor showed changes of -2.5% and 1.5% in heat and humidity tests, respectively.

Example 6 In Example 3, when 20 g of diallyl orthophthalate prepolymer and 10 g of pentaerythritol triacrylate were used in addition to 50 g of the acrylic ester solution of the condensate as the binder resin, the resistor obtained had an area of 1 KΩ/□. It had a resistance value and showed a pencil hardness of 9H or higher. This resistor tested -8.0 in heat and humidity tests, respectively.
% and 1.5% change.

Example 7 The resistive ink obtained in Example 1 was coated on a paper-phenol substrate and immediately heated for 60 seconds using a far-infrared radiation heating device with an output of 1.8 KW to produce a resistor. The distance between the heating source and the substrate is 10
cm. The resistor obtained here is 0.6KΩ/□
It had a resistance value of 9H and a pencil hardness of 9H or higher.
This resistor showed changes of -3.5% and 1.2% in heat and humidity tests, respectively.

Effects of the Invention As can be seen from the Examples and Comparative Examples, the resistance ink according to the present invention can be cured within a very short time by electron beam irradiation or a radiation heating device, and can be cured into a conventional heat-curable resistor. This provides a resistor that exhibits excellent characteristics, and has great industrial effects.

Claims (1)

[Scope of Claims] 1. A resistive ink composition comprising an acrylic ester solution or methacrylic ester solution of a bisphenol A-formaldehyde condensate and conductive fine powder. 2. An acrylic ester or methacrylic ester of a bisphenol A-formaldehyde condensate, a monomer or oligomer containing at least one acrylic group, methacrylic group, or allyl group, or a mixture thereof, and a conductive fine powder. A resistance ink composition comprising: