JPS62177074A - Electrically conductive printing ink composition - Google Patents

Abstract

PURPOSE:The titled composition, containing an acrylic resin obtained by polymerization in the presence of a polyester resin and electrically conductive powder as principal components, having improved electric conductivity, adhesivity and environmental resistance and useful for flexible printed circuit boards, etc. CONSTITUTION:A composition containing (A) 100pts.wt. electrically conductive powder, preferably resinous copper powder and (B) preferably 10-50pts.wt. acrylic resin, obtained by polymerization in the presence of a polyester resin, and preferably containing 50-100wt% methyl methacrylate based on the monomer component constituting the acrylic polymer. The content of the polyester resin in the acrylic resin of the component (B) is preferably 5-50wt%.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention is based on a conductive printing ink composition.

[Conventional technology]

In recent years, with the increase in the density of semiconductor components, electronic devices have become smaller and smaller.
With advances in light weight and thinness, flexible glint circuit boards (hereinafter referred to as FPC boards) are attracting attention because they can effectively utilize space.

As base materials for FPC boards, polyester films are used for consumer use, and polyimide films are used for industrial use.

By the way, as a method for forming a circuit on an FPC board, an FPC board having a separated polyester film as a base material, a method of screen printing using a conductive printing ink composition is becoming mainstream.

In general, since polyester film is an adhesive material, there is a limit to the number of ink materials that can adhere to it, making it difficult to select a material.

As a conductive printing ink composition capable of adhering closely to polyester films, Japanese Patent Publication No. 60-25055 discloses that a specific linear aromatic polyester resin made from benzene dicarboxylic acid and alkylene diol is mixed with fine gold ("). Mixed compositions have been proposed.

However, such conductive printing ink compositions composed of only polyester resin as a resin component are inferior in environmental resistance such as heat resistance and moisture resistance, especially heat resistance, which leads to a decrease in circuit reliability. It had a serious problem.

[Problems to be solved by the invention]

The present invention solves all the conventional problems and improves the guideability and FPC.
This invention was made in order to provide a conductive printing ink composition that has excellent adhesion to a substrate and also has excellent environmental resistance, particularly heat resistance.

[Means for solving problems]

That is, the conductive printing ink composition provided by the present invention (hereinafter referred to as the composition of the present invention) comprises (A) a conductive powder, and (B) an acrylic resin obtained by polymerization in the presence of a polyester resin. It is characterized by containing resin as a main component.

[Detailed description and examples of the invention]

The conductive powder that is component (8) of the composition of the present invention includes:
One or more types of conductive powders such as pure metals such as copper, silver, nickel, iron, gold, platinum, and palladium, powders of alloys containing these metals as a total matrix, and carbon powders are used. Among these, the effects of the present invention are particularly apparent when a dendritic metal powder or a shredded dendritic copper powder is used.

The reason for this is not clear, but in a composite conductive material containing metal powder, conductivity is developed through contact between the metal powders, so it is not possible to create a composite conductive material that has a simple spherical or scale-like shape. This is also believed to be because the dendritic metal powder having an uneven surface gives preferable results.

The acrylic resin, which is the component (B) of the composition of the present invention, has a (meth)acrylic acid ester such as an alkyl (meth)acrylic acid ester as a main monomer component, and is polymerized by a normal polymerization method, preferably by solution polymerization, in the presence of a polyester resin. It can be legally prepared.

Among them, especially 50 to 100% by weight of the monomer component
is methyl methacrylate, obtained by polymerizing only methyl methacrylate, or methyl methacrylate and (meth)acrylic acid, a (meth)acrylic acid alkyl ester having an alkyl group having 2 to 20 carbon atoms, Cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate , (meth)grecidyl acrylate, (
(meth)acrylic acid (tetrahydrofurfuryl), (meth)acrylic acid (phosphoric acid hydroxyethyl ester), etc.
meth)acrylic acid and its esters, aromatic vinyl compounds such as styrene, vinyl esters such as vinyl acetate,
The acrylic resin obtained by copolymerizing with other copolymerizable monomers such as cytinated vinyl compounds such as acrylonitrile is compatible with conductive powder and exhibits performance such as environmental resistance and conductivity. This is extremely convenient.

The ester resin used to form the acrylic resin of component (B) is, for example, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrontal acid, 3,6-nindomethylenetetrahydrophthalic acid, succinic acid, adipic acid, sebacic acid, Polyhydric carboxylic acids such as tetrachlorophthalic acid and het-acid; for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, neointer glycol,
It is produced by condensation polymerization with polyhydric alcohols such as 1,3-butylene glycol and 2,3-butylene glycol by any conventional method, and there are no particular restrictions on its type.

Among these, as the polyhydric carboxylic acid, a combination of an aromatic dibasic acid and an aliphatic dibasic acid having 4 or more carbon atoms is preferred.

For example, examples of aromatic dibasic acids include isophthalic acid and terephthalic acid, and examples of aliphatic dibasic acids include adipic acid and sebacic acid. Next, as the polyhydric alcohol, alkylene dialcohols such as ethylene glycol, neopentyl glycol, and 1,3-butylene glycol are preferable. More preferably, a polyhydric carboxylic acid component consisting of 60% by weight or more of aromatic dibasic acid and 40% by weight or less of aliphatic dibasic acid, ethylene glycol and/or
or polyester consisting of a polyhydric alcohol component of neopentyl glycol is preferred. The blending amounts of the components (A) and (B) in the composition of the present invention can be arbitrarily determined depending on the purpose of use, but there are no exceptions. 4) For 100 parts by weight of the conductive powder of the component, (
It is preferable to use component B) in an amount of 10 to 50 parts by weight. If component CB) is used in an amount less than 10 parts by weight, printability deteriorates, which is not preferable. Furthermore, if component (B) is used in an amount exceeding 250 parts by weight, the conductivity tends to decrease significantly, which is not preferable. Furthermore, it is preferable that the content of the polyester resin constituting component CB) be in the range of 5 to 50 weight Mh in the acrylic resin of component (B). If the content of the polyester resin in component (B) is less than 5% by weight, the adhesion to the FPC board and especially the bitter ester film tends to decrease, which is not preferable. In addition, polyester resin ■
) The content in the ingredients is 50 times:! If it exceeds fit %, the environmental resistance, especially the conductivity after thermal history, tends to deteriorate, which is not preferable.

The composition of the present invention may contain resins other than the above (B) and (C'l components) within a range that does not impair the object of the present invention (for example, within a range of 10 parts by weight or less per 100 parts by weight of the prisoner component). For example, vinyl polymers containing monomers such as vinyl chloride, vinyl acetate, styrene, acrylonitrile, etc. in a total weight type amount of φ or more, cellulose acetate resins such as cellulose acetate butyrate, epoxy resins, phenolic resins, alkyd resins, urethane resins, It can contain silicone resin, melamine resin, etc. In addition, as usual components used in conductive printing ink compositions, for example, solvent,
Additives, pigments, etc. can be included.

〔Example〕

The present invention will be specifically described below based on Examples. In the examples, "part J" and "r% J" mean parts by weight and % by weight, respectively.

Example-1 74.5 parts of methyl methacrylate, 0.5 part of acrylic acid, and 1.5 parts of polymerization initiator Kayaester O (manufactured by Kayaku Nouri Co., Ltd.) were mixed with 40 parts of dimethyl isophthalate and 40 parts of dimethyl terephthalate. , 20 parts of dimethyl sebacate, 60 parts of ethylene glycol, 60 parts of neopentyl glycol,
25 parts of polyester resin obtained by reacting 0.2 parts of calcium acetate and 0.1 parts of antimony trioxide at 180°C for 2 hours and then at 280°C for 2 hours, 145 parts of cyclohexanone, DBE (E, 1 .da
(manufactured by Pont da Nemours & Coa) 65
2. React in the mixed solution at 90°C for 9.5 hours. A polyester resin-modified acrylic resin solution was obtained. The resin solution has a solid content of 32.3%, a weighted average molecular weight of 55,000, and an acid value of 1.8.
showed the characteristics of To 77.5 parts of the polyester resin-modified acrylic resin solution was added 100 parts of m powder and 15 parts of cyclohexanone.
1 part and stirred at high speed to obtain a conductive printing ink composition.

The conductive printing ink composition was screen printed on a preester film using a 150 mesh screen, and after drying the printed product overnight at room temperature or for 20 minutes at 80°C, the surface resistance, adhesion, and heat resistance were evaluated. Evaluations were made of properties such as durability and moisture resistance.

Examples-2 to 8. Comparative Examples 1 and 2 Various printed products having different resin compositions were prepared using the same method as in Example 1, and the results are summarized in Table 1 as Examples and Comparative Examples.

Note 1) Resin content indicates parts by weight based on 100 parts of copper powder.

Note 2) Surface resistance was measured using a digital voltmeter TR-6843 (manufactured by Takeda Buken Co., Ltd.) using electrodes with a length of 2 cm between two electrodes.

Note 3) Adhesion was determined by cellophane tape peel test. Symbols have the following meanings.

◎Excellent. ○Excellent. △Slightly inferior. ×Very poor Note 4) Heat resistance shows the evaluation results after 14 days at 85°C.

Note 5) Moisture resistance shows the evaluation results after 14 days at 50°C x 98VRH.

Example 9 A printed product was prepared in the same manner as in Example except that 445 parts of methyl methacrylate, 30 parts of n-butyl methacrylate, and 0.5 part of acrylic acid were used, and the results are shown in Table 1. I raised it.

〔Effect of the invention〕

The conductive printing ink composition of the present invention has excellent performance in terms of conductivity, adhesion, and environmental resistance, and satisfies various properties required for forming circuits on FPC boards.
Its industrial value is extremely large.

Agent Patent Attorney Johei Yamashita Procedural Amendment (
rl Paku September 9, 1988 Commissioner of the Patent Office Black 1) Toshio Akira 1 Indication of the case Patent Application No. 16769 of 1988 2 Name of the invention Conductive printing ink composition 3 Person making the amendment Relationship with the case Patent Applicant name (603) Mitsubishi Rayon Co., Ltd. 4 Agent 105 Address 40 Toranomon 5-13-1 Toranomon, Minato-ku, Tokyo
Column 6 of Detailed Description of the Invention in the Mori Building Specification Contents of Amendment (1) Change “There is...” on the bottom line of page 2 of the specification to “There is...” .

(2) "Grecidyl acid..." on page 5, line 13 is changed to "glycidyl acid...".

(3) 5 lines from the bottom of page 9: “...Solid content: 32.3%
"Weight" is "...Solid content 32.3%, weight".

(4) 4 lines from the bottom of page 9, “...55,000 acid value...
・” is changed to “...55,000, acid value...”.

Claims (5)

[Claims] (1) A conductive printing ink composition comprising as main components an acrylic resin obtained by polymerization in the presence of (A) a conductive powder and (B) a polyester resin. (2) For 100 parts by weight of the conductive powder of component (A), (
The conductive printing ink composition according to claim (1), containing 10 to 50 parts by weight of the acrylic resin B). (3) The conductive printing ink composition according to claim (1) or (2), wherein the conductive powder of component (A) is a resinous copper powder. (4) Among the claims (1) to (3), 50 to 100% by weight of the monomer component constituting the acrylic polymer portion in the acrylic resin of component (B) is methyl methacrylate. The conductive printing ink composition according to item 1. (5) The conductive printing ink composition according to claims (1) to (4), wherein the acrylic resin as component (B) has a polyester resin content of 5 to 50% by weight.