JPS5981366A - Electrically conductive adhesive - Google Patents

Abstract

PURPOSE:To provide an adhesive having excellent adhesion and flexibility as well as sufficient electrical conductivity, by blending carbon black having a high surface area with a vinyl chloride/vinyl acetate copolymer. CONSTITUTION:10-30pts.wt. carbon black having a high surface area [pref. having a specific surface area (BET method) of 500m<2>/g or above and a DBP oil absorption (JIS K-6221-1970) of 250ml/100g] and 20-100pts.wt. liquid plasticizer such as dibutyl phthalate are blended with 100pts.wt. vinyl chloride/vinyl acetate copolymer (pref. having a vinyl chloride content of 70-95wt%, a vinyl acetate content of 30-5wt%, and a degree of polymn. of 100-1,000). The resulting electrically conductive adhesive is suitable for use in bonding electrically conductive polyvinyl chlorides to each other or the electrically conductive polyvinyl chloride to metal, particularly lead.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a four-electrode adhesive, in particular a vinyl chloride-acetic acid adhesive suitable for adhering conductive polyvinyl chloride to each other and conductive polyvinyl chloride to metals, especially lead. This paper proposes a conductive adhesive consisting of vinyl-based conductive material itself and high surface area carbon black.

When bonding a conductive polyvinyl chloride layer and a conductor in electrical contact, the adhesive is required to be conductive. There are many known adhesives for polyvinyl chloride (hereinafter referred to as PVC), and various types of conductive adhesives, various metal powders, and carponic adhesives are known. A conductive 1-1 adhesive is generally obtained by mixing a conductive 1-1 additive with the adhesive.

However, in order to achieve sufficient conductivity, the adhesion and flexibility of adhesives that are mixed with a large amount of conductive thickening agent will be greatly impaired.On the other hand, if a small amount is mixed, the adhesive will have sufficient conductive properties. is not obtained.

In view of the above, the present invention proposes an adhesive having the composition described above, which is excellent in adhesiveness and flexibility, and has sufficient tetraelectricity.

The vinyl chloride-vinyl acetate copolymer that serves as the base of the adhesive is a copolymer of two monomers, vinyl chloride and vinyl acetate, in a wide range of ratios, and also as a third monomer. A terpolymer containing a small amount (preferably 10% by weight or less) of an unsaturated carboxylic acid such as , maleic acid, or acrylic acid is used. The degree of polymerization is 100-10
Approximately 00 is appropriate. Particularly preferred are vinyl chloride components of 0 to 95% (heavy @ candy), vinyl acetate components of 5 to 30%, copolymers with a degree of polymerization of 100 to 900, especially 300 to 600, and chlorinated Vinyl component near 9~
92 ol), acid-resistant hydrogen component: 7 to 20%, male/acid ratio: 0.1 to 10, and degree of polymerization: 100 to 900.

Even if two or more types of vinyl chloride-vinyl acetate copolymers are used in combination, the amount may be as small as 50 parts or less, especially 30 parts or less per 100 parts (by weight, the same shall apply hereinafter) of the copolymer. may be used in combination with other additives that improve adhesion and flexibility. Assuming that \rui', A sum is 1, then acrylonide l)
Examples include rubber copolymers, chlorinated rubber, polyvinyl leadate, polyesters, polyurethanes, epoxy resins, and plasticizers.

Among these, particularly preferred are: amount of bound acrylonitrile: 20-50%, Mooney viscosity CM, L, ) 40-9
0 acrylonitrile copolymer and a liquid plasticizer.

Examples of liquid plasticizers include those commonly used for polyvinyl chloride, such as phthalate esters such as dibutyl phthalate, diothyl fucrate, diisodecyl phthalate 1 and 2, epoxidized oils, and epoxysphalin. Epoquin derivatives such as acid ocnal; adipic acid derivatives such as dioctyl adipate and diisodenruambate; fatty acid esters such as butyl oleate and dioctyl sebaque-1; trinolitic acid derivatives such as trioctyl trimellitate; Methylphosph x), h')
Cresyl phosphate-donatonophosphoric acid derivatives and the like are used. The appropriate amount of the plasticizer is 20 to 100 parts per 1.00 parts of the vinyl chloride-vinyl acetate copolymer. 2
If it is less than 0 parts, the adhesive becomes brittle and has poor peel strength, and
If it exceeds 100 parts, the adhesive becomes soft and the strength of the adhesive itself decreases, resulting in poor peel strength.

The high surface area tour pump rack is also characterized by its high surface area when mixed with vinyl chloride-vinyl sheath copolymer in a conventional manner. - Since the copolymer is used to form a workpiece, a small amount of the copolymer is used, and sufficient conductivity can be achieved without substantially adversely affecting the adhesion and flexibility of the copolymer. The preferred high surface area carbon black is B TCT surface area of 500+1
1. / There are ten more than S' 1. JIS K 622]
- DBP oil absorption according to 1970 is 250 ml/10
0'! It is '-'.

Adhesives that cure volume resistivity as low as 1×10 Ωm or less have a divinely useful use as a cure for sex. The amount of high surface area carbon black blended varies depending on the desired electrical conductivity, but in general, the above-mentioned /ξ electrical conductivity can be obtained by blending the high surface area carbon black in an amount of at least 10% based on the wood content. If the amount of carbon black added is increased, a product with better conductivity can be obtained, but if it is used in an amount greater than 30%, the adhesion and flexibility of the adhesive will be adversely affected, so it should be kept at 30% or less. is in good shape. A particularly preferable blending amount of the carbon blank is 15 to 2'
It is 5%.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 4 100 parts of vinyl chloride/L-vinyl acetate di-copolymer (vinyl chloride component: 85%, vinyl acetate component: 15%, 31 parts homopolymerization degree: 800), 40 parts of dioctyl phthalate and high surface area carbon black (Okashinda country, Axie, Ketchenblatt, B ■!;T surface area: 1000m
/! Oil absorption amount 3407+1. t/ ] OO! ) for 10 copies, 15 copies, 20 copies or 30 copies for 50' each.
Example 1
-4 adhesive was obtained.

Vinyl chloride-W [acid vinyl-maleic acid terpolymer (
Vinyl chloride component: 86%, vinyl acetate component: 13%, maleino acid component: 1%, average degree of polymerization: 400) l
0 parts, and 30 parts of dioctyl sebaque h and 10 parts, 15 parts, 20 parts, or 30 parts of the high surface area carbonoblast used in Example 1 were uniformly mixed using two rolls each set at 50°CiC. Examples 9 to 10 Vinyl chloride-vinyl acetate binary copolymer (vinyl chloride component 280%, vinyl acetate component: 20 coefficient Y homopolymerization degree + 560
) 100 copies, and]・]Rekren Lupos Fae 1-60
and high surface area carbon black (manufactured by Mira Yuka Co., Ltd., B
E i” surface area, 900m2/!i’ + oil absorption + 3
Adhesives of Examples 9 and 10 were obtained by uniformly mixing 10 parts or 20 parts of 50 td/W) with Example] on the same scale.

Examples 11-12 100 parts of the binary copolymer used in Example 1, 10 parts or 20 parts of the carbon black used in Example 9, and the amount of bound acrylonitrile: 40%.

l,-2-viscosity (ML): 80 acrylonide 1
Example 11. ] 2 adhesive was obtained.

Examples 13-14 Vinyl chloride-vinyl acetate-maleic acid terpolymer (vinyl chloride component: 8%, vinyl acetate component: 17%, maleic acid, 5%, average degree of polymerization: 500) 100 parts, carried out 10 parts or 20 parts of the high surface area carbon black used in Example 1 were mixed uniformly in the same manner as in Example 1, and the adhesives of Examples 13 and 14 were added.

100 parts of the binary copolymer used in Example 1]] and low surface area carbon black
BET surface area: 1.30711. /Y)
] O parts or 30 parts were uniformly mixed in the same manner as in Example 1 to obtain an adhesive of Comparative Example] and 2. The table below shows the volume resistivity at 20°C and the adhesive strength measured by the method below for each Example and Comparative Example. As is clear from the table, each example had excellent iti for all evaluation items.
It shows gender. On the other hand, although Comparative Example 1d had good adhesion, the volume resistivity was excessive, and Comparative Example 2 had a result opposite to Comparative Example 1.

The adhesive strength of the adhesive was measured by the following method.

That is, the adhesive is dissolved in a mixed solvent of 11 parts and 1 part of torniothyl ethyl keto to make a 30% solution, and this is mixed to a thickness of 1.
OOμ lead foil or conductive (9-1) V C plate, dried at 80°C for 30 minutes / An adhesive piece was created by pressing polyvinyl chloride at a heating temperature of 1.50'C for 4 minutes at a pressure of 1.5K97 cm.
width], Onun, length 100 mm short strip shape, jsoq pot 1 #if strength between two adherends, tensile speed 1.00 + rrm 7 minutes, 1 lll + constant, trial 1
Width 1. The peel strength in cm and % is 9 (~).

Claims (1)

[Scope of Claims] 1. A conductive adhesive comprising a vinyl chloride-vinyl acetate copolymer and 10 to 30 parts by weight of high surface area carbon black per 100 parts by weight of the copolymer. 2. Vinyl chloride-vinino acetate copolymer] The conductive adhesive according to claim 1, which contains a liquid plasticizer in an amount of 20 to 100 parts by weight per 00 parts by weight. 3 Vinyl chloride-vinyl acetate copolymer, vinyl chloride component: 0-95% by weight, vinyl acetate component: 5-3
2. The conductive adhesive according to claim 1 or 2, wherein the conductive adhesive has a polymerization degree of 100 to 900. 4 As a vinyl chloride-vinyl acetate copolymer, vinyl chloride component, 79 to 92 weight φ, vinyl acetate component near to 2
0 weight ratio, maleic acid 01-10 weight ratio, degree of polymerization: ] 0
The conductive adhesive according to claim 1 or 2, wherein the conductive adhesive has a molecular weight of 0 to 1900. 5. As a high surface area carbon black, the BET surface area is 500 full/WJ2), and JISK
DBP oil absorption amount by 6221-1970 is 25Q
+++, l/1. The conductive adhesive according to claims 1 to 4, which uses an adhesive having OOS' or more.