JP2624097B2 - Oil-resistant conductive ink composition and contact member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grease-resistant conductive ink composition and a contact member which can be suitably used for producing contact members such as keyboards of OA equipment such as calculators, personal computers and telephones.

[0002]

2. Description of the Related Art Conventionally, OA of calculators, personal computers, telephones, etc.
When manufacturing contact members such as keyboards for equipment,
A method of embedding a cured conductive silicone rubber containing conductive particles such as carbon black in an insulator such as a plastic or silicone rubber and molding, or a method of attaching a cured conductive silicone rubber on the insulator described above. Has been adopted.

However, in these methods, it is necessary to first cure the conductive silicone rubber composition, then manufacture a contact member (commonly called "bean") by punching or the like, and embed or paste it in a necessary portion of the insulator. When the number of contacts is large like a keyboard, or when the shape of the contacts is a complex shape such as a horseshoe shape or a rectangle with a hole in the center, it is very difficult to mold, and defective products are generated. There is a disadvantage that the rate is high.

Japanese Patent Publication No. 61-34982 discloses a method of embedding or attaching such a cured conductive silicone rubber to an insulator. Japanese Patent Publication No. 61-34982 discloses a method in which a nonconductive silicone rubber and a conductive silicone rubber containing carbon black are combined. We propose a way to make it happen. However, the integration method involves first curing a conductive silicone rubber composition containing carbon black, forming a layer of a non-conductive addition-curable silicone rubber composition containing no carbon black on the cured layer, The curing sequence in which the conductive silicone rubber composition containing carbon black is cured first, and then the silicone rubber composition containing no carbon black is cured with respect to this cured layer. If it is not adopted, it is difficult to integrate the two.First, a non-conductive silicone rubber cured layer containing no carbon black is formed, and then a layer of the conductive silicone rubber composition containing carbon black is formed thereon. It is difficult to harden and integrate.

On the other hand, a method of forming a contact portion of the keyboard using a conductive ink composition instead of the conductive silicone rubber cured product may be considered. However, although the above-mentioned problem can be solved by using a conductive ink composition, the non-elastomer-based conductive ink composition has a problem that cracks are apt to be formed in a contact portion after bonding.
Among the elastomeric conductive ink compositions, silicone elastomer-based ones have good adhesion and adhesion to various insulating base materials, but non-silicone elastomer-based ones have insulating base materials. A cured silicone rubber has the disadvantage that it does not adhere or has poor adhesion and adhesion.

Further, in recent years, while using a keyboard of OA equipment, a phenomenon that a fat gradually penetrates from the finger into the keyboard, bleeds into a contact portion of the keyboard, and a resistance value increases to cause a malfunction often occurs. It is desired to improve this phenomenon.

To solve this problem, attempts have been made to make the key itself plastic or to provide a resin or fluorosilicone rubber barrier layer between the key and the conductive member. At present, it is not practical because it leads to an increase.

For this reason, there is a demand for the development of a silicone elastomer-based conductive ink composition which can be widely used for the production of contact members such as keyboards for various OA equipments and which can satisfy human fat measures.

The present invention has been made in order to meet the above-mentioned demands, and has excellent adhesion and adhesion to various insulating base materials, particularly insulating silicone rubber, and can be produced on these base materials without limitation in curing order. It is possible to form a conductive pattern well, and to use the oil-resistant conductive ink composition and the oil-resistant conductive ink composition, which has an excellent effect of preventing penetration of fats and oils such as human fat, and thus can be suitably used for the production of contact members such as keyboards. It is an object to provide a formed contact member.

[0010]

The present inventors have made intensive studies to achieve the above object, and have found that (a) one molecule has two or more alkenyl groups bonded to a silicon atom, and 30% or more of the organic groups other than the alkenyl group bonded to the silicon atom are -Q ¹ -Rf ¹ groups (however, Rf ¹
Is a perfluoroalkyl group or a perfluoroalkyl ether group having 1 to 20 carbon atoms, and Q ¹ is a divalent hydrocarbon group).
Organopolysiloxane of centistokes or more,
(B) an organohydrogenpolysiloxane having at least two hydrogen atoms bonded to a silicon atom in one molecule, and having the following general formula (1), (2), (3) or (4): A mixture of one or both of an organohydrogenpolysiloxane I selected from hydrogenpolysiloxane and an organohydrogenpolysiloxane II represented by the following general formula (5), (c) platinum or a platinum compound, (d) Conductive carbon particles, (e) an organopolysiloxane having at least one hydrogen atom bonded to a silicon atom in one molecule and at least one group selected from an alkoxy group and an epoxy group, and (f) It has been found that the oil- and fat-resistant conductive ink composition containing a solvent can solve the above-mentioned problems.

[0011]

Embedded image(Where R¹ , R^Three, R⁹Is a hydrogen atom or char
An alkyl group having 1 to 8 atoms or a phenyl group, R^Two,
R^Four, R^Five, R⁶, R⁷, R⁸, R^Ten, R¹¹Is carbon
An alkyl group having 1 to 8 atoms or a phenyl group, Rf^TwoIs charcoal
A perfluoroalkyl group having 1 to 20 atoms or perfluoro
Low alkyl ether group, Q^TwoIs a divalent hydrocarbon group
You. k is an integer of 3 to 10, m and n are each m + n is 3.
Is a positive integer of 10 to 10. When n = 1, R^ThreeIs water
Elementary atom. a and b are each a number of 0, 1 or 2, c
Is a number from 2 to 5. Also, p, q, and r are positive
An integer and q / (p + q + r)> 0.5, but r
= 1 when R⁹Is a hydrogen atom. )

That is, an organopolysiloxane, a crosslinking agent,
A platinum compound-based addition reaction catalyst, a conductive ink composition containing conductive carbon particles and the like, by blending the above-described perfluoroalkyl group or perfluoroalkyl ether group-containing fluorosilicone as the main component organopolysiloxane, An oil-and-fat-resistant conductive ink composition having excellent adhesion and adhesion to various insulating base materials, particularly insulating silicone rubber, and having an excellent effect of preventing penetration of fats and oils such as human fats is obtained. It has been found that when an object is used as a contact member of a keyboard or the like, bleeding of grease to the keyboard contact portion can be suppressed, and occurrence of a functional failure can be prevented without performing troublesome processing. Further, the composition of the present invention is applied, for example, to a pre-cured insulating silicone rubber layer and cured, or is applied to an uncured insulating silicone rubber layer and both are heated and cured simultaneously. Thus, it is possible to integrally form the insulating silicone rubber layer and the conductive silicone rubber layer, and further, it has various complicated conductive patterns by using a screen printing method or the like. Keyboard
The inventors have found that a contact portion such as a pad can be easily formed, and have accomplished the present invention.

Accordingly, the present invention provides: (a) one molecule having two or more alkenyl groups bonded to a silicon atom, and at least 30% of the organic groups other than the alkenyl group bonded to the silicon atom are- A viscosity at 25 ° C. which is a group represented by Q ¹ -Rf ¹ group (where Rf is a perfluoroalkyl group or a perfluoroalkyl ether group having 1 to 20 carbon atoms, and Q is a divalent hydrocarbon group) (B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, and the above-mentioned organohydrogenpolysiloxane I and the above-mentioned organohydrogenpolysiloxane. Siloxane I
(C) platinum or a platinum compound; (d) conductive carbon particles; (e) one or more hydrogen atoms bonded to silicon atoms in one molecule, and an alkoxy group and an epoxy group. An oil- and grease-resistant conductive ink composition comprising an organopolysiloxane having at least one group selected from the group consisting of (f) a solvent, and a conductive material of the oil- and grease-resistant conductive ink composition on an insulating silicone rubber molded article. After applying an uncured grease-resistant conductive ink composition to a contact member on which a layer is formed by printing and a cured insulating silicone rubber molded body, and then heating and curing, the conductive layer made of conductive silicone rubber is insulated. The contact member formed on the silicone rubber molded article is provided.

Hereinafter, the present invention will be described in more detail. The oil- and fat-resistant conductive ink composition of the present invention comprises an organopolysiloxane, an organohydrogenpolysiloxane as a crosslinking agent thereof, platinum or a platinum compound, conductive carbon particles, It contains an organopolysiloxane as an adhesion improver and a solvent.

The first essential component of the oil- and fat-resistant conductive ink composition of the present invention has at least two alkenyl groups in one molecule, and accounts for 30% of the organic groups other than the alkenyl group bonded to the silicon atom. The above is the -Q ¹ -Rf ¹ group (provided that R
f ¹ is a perfluoroalkyl group or a perfluoroalkyl ether group having 1 to 20 carbon atoms, and Q ¹ is a divalent hydrocarbon group).
It is an organopolysiloxane of 00 cs or more.

Here, the above-mentioned organopolysiloxane serving as a main component can contain, for example, a vinyl group, an allyl group, a methacryl group, a hexenyl group or the like as an alkenyl group. Other organic groups bonded to the silicon atom include, for example, a methyl group, an ethyl group, a propyl group, a phenyl group, a trifluoropropyl group and F (CF (CF ₃ )
-Q ¹ -Rf ¹ groups such as CF ₂ O) ₃ -C ₃ H _6- groups (where R
f ¹ is a perfluoroalkyl group or a perfluoroalkyl ether group having 1 to 20 carbon atoms, and Q ¹ is a divalent hydrocarbon group.
To 15 to 15 monovalent hydrocarbon groups, and 30% or more, particularly 30 to 70%, of the organic groups are -Q-Rf groups. If this content ratio is less than 30%, it may swell with oils and fats and cause contact failure. Further, the organopolysiloxane has a viscosity at 25 ° C. of 100 c.
s or more, preferably 400 to 100,000 cs.

Specific examples of such an organopolysiloxane include the following.

[0018]

Embedded image (Where d, e, f, h, u, and s are each 0
The above integers m, g, i, j, v, and t are positive integers, respectively, and e / (2d + 4 + e)> 0.3, g /
(2f + g)> 0.3, j / (2h + 4 + i + j)>
0.3, v / (2u + 4 + v)> 0.3, t / (2s +
4 + t)> 0.3. )

The above-mentioned organopolysiloxane may have a partially branched structure. These organopolysiloxanes can be used alone or
It may be a mixture of more than one species.

Next, the organohydrogenpolysiloxane as the second essential component is compatible with the alkenyl group-containing organopolysiloxane of the first component and reacts with the alkenyl group in the organopolysiloxane molecule.
It acts as a cross-linking agent, has two or more hydrogen atoms bonded to a silicon atom in one molecule, and has an organic compound represented by the following general formulas (1), (2), (3) and (4). One or two selected from hydrogen polysiloxane
It is a mixture of at least one of organopolysiloxanes (I) and / or organohydrogenpolysiloxanes (II) represented by the following general formula (5).

[0021]

Embedded image(Where R¹ , R^Three, R⁹Is a hydrogen atom or char
An alkyl group having 1 to 8 atoms or a phenyl group, R^Two,
R^Four, R^Five, R⁶, R⁷, R⁸, R^Ten, R¹¹Is carbon
An alkyl group having 1 to 8 atoms or a phenyl group, Rf^TwoIs charcoal
A perfluoroalkyl group having 1 to 20 atoms or perfluoro
Low alkyl ether group, Q^TwoIs a divalent hydrocarbon group
You. k is an integer of 3 to 10, m and n are each m + n is 3.
Is a positive integer of 10 to 10. When n = 1, R^ThreeIs water
Elementary atom. a and b are each a number of 0, 1 or 2, c
Is a number from 2 to 5. Also, p, q, and r are positive
An integer and q / (p + q + r)> 0.5, but r
= 1 when R⁹Is a hydrogen atom. )

In this case, all of the above-mentioned organohydrogenpolysiloxanes need to be dissolved in the alkenyl group-containing organopolysiloxane of the first component. Therefore, the organohydrogenpolysiloxane (I)
It is necessary that the lengths of the molecules, that is, k and m + n, are each 3 to 10. In the organohydrogenpolysiloxane (II), a siloxane containing a perfluoroalkyl group or a perfluoroalkyl ether group is used. The unit q is 50% or more of the whole, that is, q /
It is necessary that (p + q + r)> 0.5. k,
m + n exceeds 10 or q / (p + q + r)
Is less than 0.5, the solubility in the first component is reduced,
Phenomena such as separation of the ink composition and deterioration of physical properties of the cured product are observed.

Such an organohydrogenpolysiloxane may have a linear, branched or cyclic structure, and specific examples thereof include the following.

[0024]

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[0025]

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This organohydrogenpolysiloxane supplies from 0.5 to 30, especially from 5 to 20, hydrogen atoms bonded to silicon atoms per alkenyl group contained in the alkenyl group-containing organopolysiloxane. It is preferable that the amount is sufficient.

The third essential component, platinum or a platinum compound, is a catalyst for an addition reaction and acts as a curing accelerator. As the platinum or platinum compound-based catalyst, for example, platinum black, alumina, those in which solid platinum is supported on a carrier such as silica,
Examples thereof include chloroplatinic acid, alcohol-modified chloroplatinic acid, a complex of chloroplatinic acid and an olefin, and a complex of platinum and vinylsiloxane, but are not limited thereto.

In the use of these catalysts, when they are solid catalysts, it is preferable to crush them finely for better dispersibility, or to make the carrier small in particle diameter and large in specific surface area. Further, with respect to chloroplatinic acid or a complex of chloroplatinic acid and an olefin, it is desirable to use these by dissolving them in a solvent such as alcohol, ketone, ether or hydrocarbon.

The desired amount of these catalysts can be used to obtain the desired curing rate. However, in order to obtain an economical viewpoint or a good cured product, the following ratios are preferably used. It is. That is, for those which are compatible with the siloxane component, such as alcohol-modified or vinylsiloxane-modified chloroplatinic acid, 0.1 to 100 ppm (in terms of platinum) with respect to the total amount of both organopolysiloxanes, and platinum black 20 to 500 ppm for solid catalysts such as
(Equivalent to platinum).

As the conductive carbon particles as the fourth essential component of the composition of the present invention, conventionally known ones usually used in conductive rubber compositions can be used. Specifically, Continex CF ( Super-conductive furnace black (SCF), such as conductive furnace black (CF) such as Continental Carbon, Vulcan C (Cabot), Continex SCF (Continental Carbon), Vulcan SC (Cabot), etc. Extra conductive furnace black (XCF) such as Asahi HS-500 (manufactured by Asahi Carbon) and Vulcan XC-72 (manufactured by Cabot), conductive channel black (CC) such as Kolux L (manufactured by Degussa), and electrified acetylene black. , Electrified Black HS-100 (Electric Acetylene black academic Kogyo Co., Ltd.), heat-treated at a high temperature of about 1500 ° C. The furnace black and channel black, and further, and the like Ketjen black EC (manufactured by Akzo), which is a type of furnace black.

When the conductive carbon particles have a high sulfur content, when the conductive ink composition is formed into an addition-curable organopolysiloxane composition, the catalyst poison of platinum or a platinum compound catalyst when stored for a long period of time. , And the curability of the composition may be deteriorated, and therefore, those having a relatively low sulfur content, particularly, acetylene black-based ones are preferably used. Further, the specific surface area of the conductive carbon particles is appropriately selected,
Although not particularly limited, a material having a mass of usually ^{2 to} 1000 m ² / g can be used.

The amount of the conductive carbon particles is appropriately selected and is not particularly limited, but is 50 to 20 parts by weight based on 100 parts (parts by weight, hereinafter the same) of the organopolysiloxane as the main ingredient.
0 parts, particularly preferably 80 to 150 parts. 50
If it is less than the part, in a one-sided open curing system (coating, screen printing method, etc.), a silicon insulating layer is easily formed on the surface layer of the cured product, the surface resistance increases, and the desired conductivity is substantially increased. When the amount exceeds 200 parts, not only the compounding operation becomes difficult, but also the siloxane content of the binder is reduced, so that the abrasion of the cured product is reduced, and thus the material may not be practically used.

The conductive ink composition of the present invention has, as a fifth essential component, at least one hydrogen atom bonded to a silicon atom in one molecule in addition to the above-mentioned components, and further has an alkoxy group and an epoxy group. The composition contains at least one organopolysiloxane. By incorporating this organopolysiloxane, the adhesiveness can be significantly improved. This organopolysiloxane is
It acts to improve self-adhesiveness to the substrate to which the conductive ink composition is applied. Examples of such an organopolysiloxane include, for example,
No. 21026, having an alkoxysiloxy group, Japanese Patent Publication No. 53-13508, having an epoxy-containing hydrocarbon group, and Japanese Patent Publication No. 59-5219.
And the like having an alkoxysiloxy group and an epoxy-containing hydrocarbon group disclosed in Japanese Patent Application Laid-Open No. H10-163, 1988. More specifically, the following silicon compounds can be exemplified, but not limited thereto.

[0034]

Embedded image

These can be used by appropriately increasing the degree of polymerization and the like according to the application.

The above-mentioned organopolysiloxane is preferably used in a proportion of 0.5 to 20 parts, particularly 1 to 10 parts, per 100 parts of the organopolysiloxane as the main ingredient of the present invention.

The conductive ink composition of the present invention contains a solvent as a sixth essential component in order to adjust its viscosity and improve workability.

As the solvent, a volatile organic compound is preferably used. Excluding those that poison the catalyst for the addition reaction, those that cause a dehydration reaction, and those that have an alkenyl group in the molecule and disrupt the cross-linking balance, are used. All volatile organic compounds which can dissolve the fluorosilicone can be used. As the volatile organic compound, specifically, acetone,
Ketones such as methyl ethyl ketone and methyl-t-butyl ketone; esters such as methyl acetate, ethyl acetate and isobutyl acetate; cyclic ethers such as furan and tetrahydrofuran; 1-propyl ether, n-butyl ether;
Ethers such as anisole, cyclic siloxanes such as octamethylcyclotetrasiloxane, 1,3,5,7-tetrakis (trifluoropropyl) -1,3,5,7-tetramethylcyclotetrasiloxane, hexamethyldisiloxane, Octamethyltrisiloxane, the following formula (6)
And chlorinated hydrocarbons such as carbon tetrachloride, perchloroethylene and trichloroethylene, and fluorinated hydrocarbons such as octafluoropropane. These solvents may be used alone. Or 2
More than one kind can be mixed and used.

[0039]

Embedded image

The amount of the solvent used is appropriately selected.
3 to 2 with respect to 100 parts of the organopolysiloxane as the main agent
000 parts, preferably 200 to 1000 parts.

Further, to the composition of the present invention, for example, triallyl isocyanurate, triallyl trimellitate or a compound obtained by modifying these with siloxane may be added as a compound for enhancing the adhesive effect in order to further improve the adhesiveness. For example, one or two of the compounds having the following structures
More than one species can be added.

[0042]

Embedded image

[0043]

Embedded image

[0044]

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The amount of the above compound is not particularly limited, but is preferably 0.5 to 3 parts with respect to 100 parts of the organopolysiloxane as the main ingredient.

Further, in order to reinforce the strength of the cured product, the composition of the present invention is disclosed in JP-B-38-26771 and JP-B-45-94.
SiO ₂ units disclosed in 76 JP, CH ₂ = CH
(R _'2) -SiO _0.5 units and R' ₃ -SiO _0.5 units (R 'is a monovalent hydrocarbon group containing no unsaturated aliphatic group)
It is also possible to add an organopolysiloxane having a resin structure containing The amount of the organopolysiloxane added is not particularly limited, but it is preferable to use the organopolysiloxane in a proportion of 30 parts or less based on 100 parts of the main component organopolysiloxane. If the addition amount exceeds 30 parts, not only is it economically disadvantageous, but also the cured rubber becomes hard and brittle.

Further, for the purpose of controlling the curing rate of the composition, CH ₂ ＣC disclosed in JP-B-48-10947 is disclosed.
Organopolysiloxanes containing HR'SiO units (R 'is as defined above); acetylene compounds disclosed in U.S. Pat. No. 3,445,420; and U.S. Pat.
The ionic compound of a heavy metal disclosed in the specification of No. 49 can be blended. Further, in order to improve the thermal shock resistance, flexibility and the like of the cured product, a non-functional organosiloxane can be blended.

Further, other optional components, for example, red iron oxide, black iron oxide, cerium oxide and the like, a heat resistance improving agent, a flame retardant imparting agent such as benzotriazole, zinc carbide and manganese carbonate, an addition reaction controlling agent such as an acetylene compound, A foaming agent and the like can be appropriately compounded.

The method for producing the conductive ink composition of the present invention is not particularly limited, and it can be produced by kneading the above components.

The conductive ink composition of the present invention can be applied to a substrate made of various kinds of electric insulation resistors, cured and used for producing a contact member such as a keyboard.
In this case, the electric insulation resistor has a volume resistance of 10 ¹⁰ Ω.
・ Cm or more is preferably used. Further, the properties thereof may be resin-like or elastic. Specifically, as such an electrical insulation resistor, for example, ABS-type resin, PET resin, acrylic resin, polycarbonate resin, PBT Resins, thermoplastic resins such as PPS resins, and thermosetting resins such as epoxy resins and urethane resins. When the base is hard resinous,
Preferably, the thickness of the conductive silicone rubber is about 0.5 to 3 mm. When the thickness is less than 0.5 mm, for example, in the production of a keyboard or the like, not only is the feel when pressing a key is bad, but also a large distortion is applied to the interface between the substrate and the conductive silicone rubber, and the adhesion durability is reduced. A problem may occur, and when a coating having a thickness of more than 3 mm is applied, it may be not only industrially difficult but also economically disadvantageous. In addition to the silicone rubber, various synthetic rubbers can be used as the base material as the elastic body. Particularly, in the production of keyboards and the like, silicone rubber is desirably used from the viewpoint of electrical insulation and durability. Applying the conductive ink composition to an appropriate pattern by a suitable printing method such as a screen printing method so as to have a thickness (usually about 5 to 500 μm) on a portion to be a contact site on the rubber molded body;
By hardening, a keyboard or the like can be created. In this case, according to the composition of the present invention, an ink composition comprising a conductive silicone rubber composition can be applied to a cured insulating silicone rubber containing no carbon black and cured. In addition, after the insulating silicone rubber composition is previously cured and after-cured to complete the curing, the oil-resistant conductive ink composition of the present invention may be applied and cured by heating. The composition of the present invention has good adhesion and adhesion to the insulating silicone rubber composition as the base material, and therefore, is cast on the base material (molded product which has been first cured) made of the insulating silicone rubber composition. After the conductive ink composition of the present invention is applied, it is also possible to perform after-curing and curing and bonding at the same time. When the oil- and fat-resistant conductive ink composition of the present invention is coated on the base material and cured by heating, a silicone rubber product in which the conductive silicone rubber layer and the insulating silicone rubber layer are integrated can be obtained. . When a cured layer of the composition of the present invention is formed on an insulating silicone rubber molded article, a primer can be used, if necessary, although not essential.

[0051]

The oil- and fat-resistant conductive ink composition of the present invention comprises:
It has excellent adhesion and adhesion to various insulator base materials, especially insulating silicone rubber, and the resulting cured product has excellent wear resistance. Furthermore, when the composition of the present invention is used as a contact member of a keyboard, when the base material is an insulating silicone rubber, the composition has a function of barriering oils and fats (human fat, etc.) penetrating from the surface of the key, and has a conductive property. Since the performance is not reduced, the life of the keys of the OA equipment can be significantly extended. For this reason, the composition of the present invention is suitably used for the production of contact members such as keyboards, and in particular, a contact member in which a conductive layer of the composition of the present invention is formed by printing on an insulating silicone rubber molded product is suitable for screen printing or the like. The contact portion of a keyboard or the like having a complicated conductive pattern can be easily formed by a technique. In this case, the composition of the present invention can be applied to a pre-cured insulating silicone rubber molded article, and cured.
Apply it on the insulating silicone rubber molding only for the next curing,
Even when both are cured at the same time, a contact member having a conductive contact layer having excellent adhesion can be obtained, and the production efficiency is also excellent.

[0052]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. All parts in each example are parts by weight. The viscosity indicates a value at 25 ° C.

Example 1 An organopolysiloxane containing a trifluoropropyl group represented by the following formula (7) and having both ends capped with a trivinylsilyl group (viscosity: 400 c
s) 100 parts and 70 parts of acetylene black HS-100 (manufactured by Denki Kagaku) having a specific surface area of 30 m ² / g were added and kneaded.

[0054]

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After kneading, 0.15 part of an octanol solution of chloroplatinic acid (a product having a platinum content of 2% by weight), 0.30 part of ethynylcyclohexanol, and 1.0 part of triallylisocyanurate were added and kneaded. Next, this was mixed on a three-roll mill and mixed with methyl-n-butyl ketone 5.
00 parts, 15.5 parts of a crosslinking agent represented by the following formula (8), and a compound 5.0 represented by the following formula (9) as an adhesion aid
The conductive ink composition I was prepared by adding and dissolving the resultant mixture in a mixed solution.

[0056]

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The obtained conductive ink composition I was applied on a PET film with a bar coater, air-dried for 30 minutes, and dried.
Heat and cure at 0 ° C for 60 minutes, and follow the Rubber Association Standards (“Volume resistivity test method for conductive rubber and plastics” 2
301-1969), a thickness of 0.02
mm, the volume resistivity was 1.1 Ω · cm.

The conductive ink composition I was screen-printed onto a contact (diameter: 3 mm) of a molding-cured sheet of peroxide-curable silicone rubber KE951 (manufactured by Shin-Cho Kagaku Kogyo Co., Ltd., JISA hardness: 50). And air-dried for 30 minutes, and baked and cured at 150 ° C. for 60 minutes. A cured layer of this conductive ink composition was formed on the molded cured sheet with good adhesion, and a keying test was performed using the cured layer as a contact key. No interfacial peeling was observed even after 500,000 times.

Further, after the contact key KE 951 was left in tallow for 10 days, the contact resistance value of the contact portion was measured. did it. Table 1 summarizes the above results.

Example 2 In place of the vinyl group-containing organopolysiloxane having a trifluoropropyl group of Example 1, 100 parts of an organopolysiloxane (viscosity: 5800 cs) represented by the following formula (10) was used, and a crosslinking agent was used. Was replaced with 21.5 g of a compound represented by the following formula (11) to prepare a conductive ink composition II in the same manner as in Example 1.

[0061]

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The obtained conductive ink composition II was tested for volume resistivity, tableting test, and test with tallow in the same manner as described above. Table 1 shows the results.

COMPARATIVE EXAMPLE Instead of the vinyl group-containing organopolysiloxane having a trifluoropropyl group of Example 1, a polydimethylsiloxane blocked by a vinyldimethylsilyl group at both ends represented by the following formula (12) (having a viscosity of 1
000 cs), and a comparative composition was prepared in the same manner as in Example 1 except that 2.8 g of the compound of the above formula (8) was added as a crosslinking agent.

[0064]

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The volume resistivity, tableting test and test with tallow of the obtained comparative composition were carried out in the same manner as described above. Table 1 shows the results.

[0066]

[Table 1]

From the results shown in Table 1, it was confirmed that the oil- and fat-resistant conductive ink composition of the present invention was excellent in adhesion and adhesion to insulating silicone rubber, and also excellent in preventing penetration of human fat. Was done.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C09D 11/00 PSV C09D 11/00 PSV H01B 1/22 H01B 1/22 A

Claims (3)

(57) [Claims] 1. (a) bonded to a silicon atom in one molecule
Having two or more alkenyl groups and bonded to a silicon atom
30% or more of the organic groups other than the alkenyl group
¹-R f¹Group (however, Rf¹Is a par of 1 to 20 carbon atoms
A fluoroalkyl group or a perfluoroalkyl ether group,
Q¹Is a divalent hydrocarbon group).
Oil having a viscosity at 5 ° C of 100 centistokes or more
Ganopolysiloxane, (b) bonds to silicon atom in one molecule
Organohydrides having at least two combined hydrogen atoms
Is a rosogenpolysiloxane, and has the following general formula
Organo represented by (1), (2), (3) or (4)
Organoha selected from hydrogen polysiloxane
Represented by the following general formula (5):
With the organohydrogenpolysiloxane II
A mixture of any one or both,(Where R¹ , R^Three, R⁹Is a hydrogen atom or char
An alkyl group having 1 to 8 atoms or a phenyl group, R^Two,
R^Four, R^Five, R⁶, R⁷, R⁸, R^Ten, R¹¹Is carbon
An alkyl group having 1 to 8 atoms or a phenyl group, Rf^TwoIs charcoal
A perfluoroalkyl group having 1 to 20 atoms or perfluoro
Low alkyl ether group, Q^TwoIs a divalent hydrocarbon group
You. k is an integer of 3 to 10, m and n are each m + n is 3.
Is a positive integer of 10 to 10. When n = 1, R^ThreeIs water
Elementary atom. a and b are each a number of 0, 1 or 2, c
Is a number from 2 to 5. Also, p, q, and r are positive
An integer and q / (p + q + r)> 0.5, but r
= 1 when R⁹Is a hydrogen atom. ) (C) platinum or white
Gold compound, (d) conductive carbon particles, (e) silicon atom
Having one or more bonded hydrogen atoms in one molecule, and
At least one of groups selected from a oxy group and an epoxy group
Compounded with organopolysiloxane having (f) solvent
An oil-and-fat-resistant conductive ink composition, comprising: 2. A contact member formed by printing a conductive layer of the oil- and fat-resistant conductive ink composition according to claim 1 on an insulating silicone rubber molded article. 3. An uncured oil- and fat-resistant conductive ink composition according to claim 1 is applied to a cured insulating silicone rubber molded article, and then cured by heating, so that the conductive layer made of the conductive silicone rubber has an insulating property. 3. The contact member according to claim 2, which is formed on a silicone rubber molded body.