Silicone rubber molded body and its manufacturing method

Abstract

A silicone rubber molded body (1) having a conductive ink coating layer (3) on any part of its surface, wherein the conductive ink coating layer (3) contains a hydrolyzable organosilicon compound; by specifying the saturated water absorption rate of the silicone rubber molded body to be 0.10 to 1.50% by mass and / or adding water to the conductive ink coating, the affinity between the surface of the silicone rubber molded body (1) and the conductive ink coating layer (3) is improved; the ink residue area of ​​the conductive ink coating layer (3) after an abrasion test is an average of 20% or more and 100% or less. Thus, a silicone rubber molded body with improved affinity between silicone rubber and conductive ink, improved durability relative to continuously applied stress, and long-term service stability, and a method for manufacturing the same, are provided.

Description

Technical Field

[0001] This invention relates to a silicone rubber molded body with a conductive ink coating cured on its surface, used in switching functional elements, flexible circuits, electrical contacts, etc., and a method for manufacturing the same. Background Technology

[0002] Previously, liquid silicone compositions based on curable polysiloxanes and diluted with solvents were widely used in various applications such as coating and marking due to their excellent heat resistance and weather resistance. In particular, conductive liquid silicone compositions that become conductive by combining with conductive carbon black are used in switching components or flexible circuits due to their properties.

[0003] Patent Document 1 proposes to uniformly mix carbon black with a polyorganosiloxane containing alkenyl groups with terminal reactive groups to prepare a base compound, and then add a solvent to form a conductive ink. Patent Document 2 proposes to form a circuit by using conductive ink on the surface of an electrically insulating sheet such as silicone rubber. Patent Document 3 proposes to form at least a perforated portion of a conductive component as a printed body using conductive ink in a capacitive contact switch using silicone rubber. Patent Document 4 proposes a heated fixing roller coated with a cured film containing a hydrolytic condensate of colloidal silica and a specific silicon compound, and a linear dialkyl polysiloxane diol.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-075970

[0007] Patent Document 2: Japanese Patent Application Publication No. 2012-084294

[0008] Patent Document 3: Japanese Patent Application Publication No. 2016-100092

[0009] Patent Document 4: Japanese Patent Application Publication No. 10-142987 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] However, conventional silicone rubber molded articles suffer from low affinity between silicone rubber and conductive inks, and low durability under continuous stress. For example, Patent Document 4 uses linear dialkyl polysiloxane diols to impart release properties, but this reduces the affinity between silicone rubber and conductive inks.

[0012] In order to solve the above-mentioned problems, the present invention provides a silicone rubber molded article with improved affinity between silicone rubber and conductive ink, improved durability relative to continuously applied stress, and long-term use stability, and a method thereof.

[0013] Methods for solving problems

[0014] This invention relates to a silicone rubber molded body having a conductive ink coating layer on any portion of the surface of a silicone rubber molded body. The silicone rubber molded body is selected from at least one type selected from compounded silicone rubber molded bodies and addition-cured silicone rubber molded bodies, and does not contain linear dialkyl polysiloxane diols. The conductive ink coating layer contains a hydrolyzable organosilicon compound. The affinity between the surface of the silicone rubber molded body and the conductive ink coating layer is improved by selecting at least one of the following: specifying the saturated water absorption rate of the silicone rubber molded body to be 0.10–1.50% by mass and adding water to the conductive ink coating. When the surface of the conductive ink coating layer is subjected to an abrasion test using the JIS L10968.19.3C method (Taber method), the average residual ink area is 20% or more and 100% or less.

[0015] In the manufacturing method of the silicone rubber molded body of the present invention No. 1, the saturated water absorption rate of the silicone rubber molded body is specified to be 0.10 to 1.50% by mass. An ink coating layer is formed by coating a conductive ink containing a hydrolyzable organosilicon compound onto any part of the surface of the silicone rubber molded body, thereby obtaining a silicone rubber molded body. When the surface of the conductive ink coating layer of the silicone rubber molded body is subjected to an abrasion test using the JIS L10968.19.3C method (Taber method), the ink residue area is on average 20% or more and 100% or less.

[0016] In the manufacturing method of the silicone rubber molded body of the present invention No. 2, an ink coating layer is formed by coating a conductive ink containing a hydrolyzable organosilicon compound and water onto any part of the surface of the silicone rubber molded body, thereby obtaining a silicone rubber molded body. When the surface of the conductive ink coating layer of the silicone rubber molded body is subjected to an abrasion test using the JIS L10968.19.3C method (Taber method), the average residual ink area is 20% or more and 100% or less.

[0017] Invention Effects

[0018] The silicone rubber molded body of the present invention has a conductive ink coating layer on any portion of the surface of the silicone rubber molded body, which improves the affinity between the surface of the silicone rubber molded body and the conductive ink coating layer. The ink residue area during abrasion testing of the conductive ink coating layer is specified to be an average of 20% or more and 100% or less. Therefore, a silicone rubber molded body with high affinity between silicone rubber and conductive ink, improved durability relative to continuously applied stress, and long-term service stability can be provided. According to the manufacturing methods of the silicone rubber molded body of the present invention No. 1 and No. 2, the silicone rubber molded body of the present invention can be manufactured efficiently and rationally. Attached Figure Description

[0019] Figure 1 A is a schematic plan view of a silicone rubber molded body used in an abrasion test to determine the ink residue area in one embodiment of the present invention. Figure 1 B is Figure 1 A schematic perspective view of the wear test apparatus for A.

[0020] Figure 2 This is a schematic plan view of a comb-shaped electrode used in measuring the contact resistance value of a conductive ink coating layer according to an embodiment of the present invention. Detailed Implementation

[0021] This invention relates to a silicone rubber molded body having a conductive ink coating layer on any portion of its surface. The silicone rubber molded body is at least one selected from compounded silicone rubber molded bodies and addition-cured silicone rubber molded bodies, and does not contain linear dialkyl polysiloxane diols. If linear dialkyl polysiloxane diols are included, the mold release properties are improved, while the affinity with the conductive ink is reduced. Furthermore, the conductive ink coating layer contains a hydrolyzable organosilicon compound.

[0022] In this invention, to improve the affinity between silicone rubber and conductive ink, the saturated water absorption rate of the silicone rubber molded body is specified to be 0.10 to 1.50% by mass, and / or water is added to the conductive ink coating. The preferred saturated water absorption rate of the silicone rubber molded body is 0.15 to 1.40% by mass. To achieve the saturated water absorption rate of the silicone rubber molded body as described above, commercially available silicone rubber materials are used. Examples include compounded silicone rubber raw materials manufactured by Dow Toray, such as "RBB6650-50BASE", "RBB2004-50BASE", "RBB2070-50BASE", and "SE1185U".

[0023] The water added to the conductive ink coating is preferably 0.1 to 3.5 mol% relative to the organosilicon compound contained in the ink coating, more preferably 0.3 to 3.3 mol%, and even more preferably 0.6 to 3.1 mol%. Therefore, the ink residue area on the surface of the conductive ink coating layer during abrasion testing is on average 20% to 100% and preferably 25% to 95% and even more preferably 25% to 90%, which improves durability against continuously applied stress. The ink residue area is determined using the JIS L10968.19.3C method (Taber method).

[0024] When water is added to a conductive ink coating, and the monomer residue rate of the hydrolyzable organosilicon compound in the waterless conductive ink coating is set to 100%, the water added to the conductive ink coating preferably results in a monomer residue rate of 45% to 95% for the hydrolyzable organosilicon compound contained in the conductive ink coating layer, more preferably 50% to 90%. The hydrolysis rate of the organosilicon compound in the ink can be determined based on... 29 The peak intensity of organosilicon monomers in Si-NMR is determined from the relative intensity, with the sample without added H2O set at 100%.

[0025] The surface adhesion of the aforementioned silicone rubber molded body, measured according to JIS Z 0237 under the following conditions: pressing speed: 2 mm / s, pressing load: 100 gf, pressing holding time: 5 s, lifting speed: 2 mm / s, and probe diameter: 5 mm, is preferably 1.5 to 3.0 gf·s, more preferably 1.6 to 2.5 gf·s. This further improves durability against continuously applied stress and enhances long-term stability.

[0026] The silicone rubber molded body of the present invention is at least one selected from compounded silicone rubber molded bodies cured with organic peroxides and addition-cured silicone rubber molded bodies. The compounded silicone rubber material preferably has the following composition.

[0027] (A) Using R 1 a SiO （4-a） / 2 The indicated amount of organopolysiloxane: 100 parts by weight

[0028] (where R) 1 (The groups are the same or different unsubstituted or substituted monovalent hydrocarbon groups, where a is a positive number ranging from 1.95 to 2.05.)

[0029] (B) The specific surface area based on the BET adsorption method is 50 m². 2 Fillers such as reinforced silica (g or higher): 5-100 parts by weight

[0030] (C) Organic peroxides: effective amount

[0031] Examples of organic peroxides include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dicumyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane, di-tert-butyl peroxide, tert-butyl peroxybenzoate, and 1,6-hexanediol-bis-tert-butyl peroxycarbonate. The amount of organic peroxide added is preferably 0.1 to 15 parts by weight, and particularly preferably 0.2 to 10 parts by weight, relative to 100 parts by weight of the compounded silicone rubber component. If the amount added is too small, the crosslinking reaction cannot be fully carried out, sometimes resulting in decreased hardness, insufficient rubber strength, increased compression set, and other property deterioration. If the amount is too large, sometimes more decomposition products of the curing agent occur, leading to increased compression set and other property deterioration, or increased discoloration of the resulting sheet. Commercially available products can be used in the compounded silicone rubber material.

[0032] Compared to addition-reactive or condensation-reactive silicone rubbers, compounded silicone rubbers possess superior characteristics such as rubber strength, tensile strength, durability, heat resistance, and weather resistance, and are widely used as rubber molded bodies. In particular, conductive silicone rubber molded bodies, formed by coating their surfaces with conductive fillers and then curing them, are used in switching components or circuits. In conventional silicone rubber molded bodies using conductive filler-containing coatings and inks, the adhesion durability of the conductive ink has repeatedly deteriorated. To address this issue, this invention reveals a correlation between the adhesion durability of the conductive filler-containing ink to silicone rubber and the water absorption rate of the silicone rubber, the monomer residue rate of the organosilicon compound in the conductive filler-containing ink, and the adhesion characteristics of the silicone rubber. Furthermore, this invention is also effective for addition-reactive liquid silicone rubbers.

[0033] In the compounded silicone rubber composition, fillers such as dry or wet silica, surface-treated dry or wet silica, talc, clay, mica, calcium carbonate, aluminum hydroxide, alumina, and glass fiber can also be added; cerium compounds such as cerium oxide, cerium hydroxide, and cerium octanoate can also be added; iron oxides such as ferric oxide and ferric octanoate can also be added; heat-resistant improvers such as titanium dioxide can also be added; and flame-retardant additives such as azo compounds, iron(III) oxide, and platinum compounds can also be added. Furthermore, this silicone rubber composition can be obtained by mixing it using rubber compounding machines such as kneaders and two-roll mills, and then molding it using conventional methods such as compression molding, extrusion molding, injection molding, and calendering to cure it.

[0034] The raw material for addition-curing silicone rubber molded articles, namely liquid silicone rubber material, can be commercially available. The following composition is preferred for addition-curing liquid silicone rubber materials.

[0035] (A) Basic polymer composition: an organopolysiloxane containing an average of more than one silicon atom bonded with an alkenyl group per molecule.

[0036] (B) Crosslinking component: an organopolysiloxane containing an average of more than one silicon atom bonded with a hydrogen atom per molecule, wherein the crosslinking component is 0.01 to 3 moles per mole of the alkenyl group bonded with silicon atoms in component A above.

[0037] (C) Catalyst composition: Platinum group metal catalyst, in an amount of 0.01 to 1000 ppm relative to component A by atomic weight.

[0038] (D) The specific surface area based on the BET adsorption method is 50 m². 2 Fillers such as reinforced silica (g or more): 5 to 100 parts by weight relative to 100 parts by weight of the base polymer component.

[0039] Commercially available products are divided into Liquid A and Liquid B. Liquid A contains basic polymer components and catalyst components, while Liquid B contains basic polymer components and crosslinking components. Before use, Liquid A and Liquid B, along with any other required components, are added and mixed. After molding, the mixture is allowed to solidify.

[0040] In the compositions of the present invention, other components besides those described above may also be added as needed. For example, heat-resistant improvers such as iron oxide red, titanium oxide, and cerium oxide, flame retardants, and curing delay agents may also be added. Organic or inorganic particulate pigments may also be added for coloring or tinting purposes. As materials added for purposes such as filler surface treatment, organosilicon containing alkoxy groups may also be added. In addition, organopolysiloxanes without addition curing reactive groups may also be added. From a workability perspective, a viscosity of 10 to 100,000 mPa·s at 25°C is preferred, and more preferably 100 to 10,000 mPa·s is preferred.

[0041] The contact resistance value of the aforementioned conductive ink coating layer is preferably below 300Ω, more preferably 10-200Ω, and even more preferably 10-100Ω. This ensures optimal electrical conductivity. The conductive filler in the conductive ink may include carbon black, petroleum graphite, petroleum graphene, carbon nanotubes, carbon fibers, etc. if it is carbon-based; silver, copper, aluminum, nickel, tin, silver-plated copper powder, etc. if it is metal-based; tin oxide, indium oxide, zinc oxide, potassium titanate powder, etc. if it is a metal-metal oxide coating system; and coating materials such as those for surface coating of glass beads and mica powder, or coating of glass fibers and carbon fibers.

[0042] The aforementioned conductive ink contains conductive fillers and hydrolyzable organosilicon compounds. When the ink is set at 100% by mass, it is preferable to add 5 to 30% by mass of known materials such as carbon black as conductive fillers. When the ink is set to 100% by mass, it is preferable to add 5 to 30% by mass of known materials such as methyl silicate, ethyl silicate, propyl silicate, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, methyltri(methoxyethoxy)silane, vinyltri(methoxyethoxy)silane, methyltripropenoxysilane, vinyltripropenoxysilane, methyltriacetoxysilane, vinyltriacetoxysilane, methyltri(acetone oxime)silane, vinyltri(acetone oxime)silane, methyltri(methylethylketone oxime)silane, and vinyltri(methylethylketone oxime)silane as hydrolyzable organosilicon compounds. Examples of suitable solvents include toluene, xylene, cyclohexane, n-hexane, n-heptane, n-octane, nonane, naphtha, mineral oil, and petroleum ether. These solvents can be used alone or in combination of two or more. Commercially available conductive inks can be used. This invention does not contain acidic colloidal silica. The presence of acidic colloidal silica reduces conductivity and is therefore undesirable.

[0043] The following description uses accompanying drawings. In the drawings, the same symbol represents the same object. Figure 1 A is a schematic plan view of the silicone rubber molded body 1 used in an abrasion test to determine the ink residue area in one embodiment of the present invention. Figure 1 B is Figure 1 A schematic perspective view of the wear testing apparatus 5 in section A. This friction test, conducted according to JIS L1096, uses a Taber type wear testing machine to determine the area of ​​ink residue. The silicone rubber molded body 1 is formed into a sheet 2 with a diameter L4 of 120 mm and a thickness of 2 mm. Conductive ink is coated onto its surface and then cured by heat. The coated portion 3 of the cured conductive ink is shown below. Figure 1 As shown in Figure A, the width L1 = 4 mm and the length L2 = 15 mm form a ring.

[0044] Regarding the wear testing apparatus 5, the silicone rubber molded body 1 is placed on a rotary table 6 and rotated as indicated by the arrow (the rotary table 6 rotates at 70 rpm). Friction wheels 7a and 7b are arranged on the silicone rubber molded body 1 and rotated in opposite directions as indicated by the arrow. The combined load of the friction wheels 7a and 7b is 250 gf, and the rotation speed is 70 rpm. Rotation continues while attracting wear powder. The contact portion 4 of the wear wheels is annular, with an outer diameter L5 of approximately 88 mm and a width L3 of approximately 10 mm.

[0045] Example

[0046] The following describes the embodiments. However, this invention should not be construed as being limited to the following embodiments.

[0047] <Ink Residue Area>

[0048] According to JIS L1096, the area of ​​ink residue was determined using a Taber type abrasion tester manufactured by Toyo Seiki Co., Ltd.

[0049] Silicone rubber: Use 2mm thick sheets.

[0050] Conductive ink: as described above Figure 1 The AB specification states that the width L1 = 4mm and the length L2 = 15mm are used to form a ring, which is then heated and cured at 200℃ for 30 minutes.

[0051] Test conditions: 250gf, 70rpm, abrasive wheel (320 grit sandpaper), 300 rotations, the residual rate of ink on the coated surface was calculated as area % by binarization of white and black. The test was conducted 3 times, and the average value was calculated.

[0052] <Saturated water absorption rate>

[0053] A silicone rubber sample measuring 50 mm in length, 50 mm in width, and 2 mm in height was stored at 30°C and 60% RH. After 24 hours and 96 hours, the sample was removed and its weight was measured at 25°C and 25% RH. Since the difference in weight change after 24 hours and 96 hours was less than 0.01%, the weight increase rate after 96 hours was taken as the saturated water absorption rate.

[0054] <Adhesion>

[0055] The silicone rubber samples were tested using a TAC1000 viscosity tester (in accordance with JIS Z0237): manufactured by RHESCA (compression speed: 2 mm / s, compression load: 100 gf, compression holding time: 5 s, lifting speed: 2 mm / s, probe diameter: 5 mm, test temperature: room temperature, n=3).

[0056] In addition, the adhesion force of the molded body was measured on the silicone rubber sample before ink coating.

[0057] <Relative to the amount of water added to the ink>

[0058] A specified amount of ion-exchange water was added to the ink, mixed at room temperature, and after 24 hours, NMR analysis and ink coating were performed. The amount of ion-exchange water added was calculated based on the molecular weight and concentration of the organosilicon compound, and was added at 0.75, 1.50, 2.25, and 3.0 times its molar value.

[0059] <Residual monomer content of organosilicon compounds after hydrolysis in inks>

[0060] Regarding the hydrolysis rate, by analyzing from the data... 29 The peak intensity of organosilicon monomers in Si-NMR was determined from the relative intensity, with the sample without added H2O set at 100%. Table 1 shows the "Ink Monomer Residual Rate".

[0061] <Contact resistance value of conductive ink coating layer>

[0062] Comb-shaped electrode 8 Figure 2 (A is an enlarged view) shows a line width of 0.25 mm, an electrode spacing of 0.5 mm, and an electrode thickness of 18 μm. The dimensions of the contact resistance measuring part 9 are 10 mm in length and 2.5 mm in width. The clip-type lead is fixed to the electrode 10 of the clip-type lead fixing part. A DC four-terminal resistance tester (milliohm level tester 3540, range 300Ω, measuring current 1mA, manufactured by Hioki Electric Co., Ltd.) is used, with the ink coating layer in contact with the comb-shaped part of the contact resistance measuring part 9. The sample is held under a load of 100N and the resistance is measured after 60 seconds. Figure 2 The values ​​inside are dimensions (unit: mm).

[0063] (Examples 1-11, Comparative Examples 1-2)

[0064] [Silicone Rubber Manufacturing Method]

[0065] Add 2.1g of vulcanizing agent (peroxide silicone masterbatch, RC4-50P (made by DowTORAY, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, 50% silicone oil)) to 300g of commercially available silicone base polymer, and mix using a two-roll mill. Then, vulcanize under pressure at 170°C for 10 minutes. Next, vulcanize a second time in a hot air circulating oven at 200°C for 4 hours.

[0066] The various organosilicon-based polymers are as follows.

[0067] RBB6650-50BASE: Manufactured by Dow Toray, a compound silicone rubber raw material.

[0068] RBB2004-50BASE: Manufactured by Dow Toray, a compound silicone rubber raw material.

[0069] RBB2070-50BASE: Manufactured by Dow Toray, a compound silicone rubber raw material.

[0070] SE1185U: Manufactured by Dow Toray, a compound silicone rubber raw material.

[0071] [Conductive ink coating]

[0072] 310 mL of solvent (hydrocarbon solvent: solvent S) was added to 40 g of commercially available conductive ink (PRK-3C: manufactured by Dow TORAY). In Examples 6-9 and 11, the amounts of ion-exchanged water shown in Table 1 were added. Figure 1 As shown, the ink was applied to a silicone rubber surface with a length of 15 mm, a width of 2 mm, and a drying amount of 0.1 g. The surface was then dried and sintered in a hot air circulating oven at 200°C for 30 minutes.

[0073] Table 1 summarizes the conditions and results.

[0074]

[0075] From Table 1, we can see that:

[0076] (1) The saturated water absorption rate of the silicone rubber in Examples 1-4 and 10 is higher than that in Comparative Examples 1-2. The affinity between the silicone rubber and the conductive ink is improved, and the adhesion of the ink and the residual area of ​​the ink are increased.

[0077] (2) Although the saturated water absorption rate of the silicone rubber in Examples 6 to 9 is outside the range of 0.10 to 1.50, by adding a specified amount of water to the conductive ink, the residual rate of the monomer after hydrolysis of the organosilicon compound in the ink is 52 to 87%, thereby improving the affinity between the silicone rubber and the conductive ink, increasing the adhesion of the ink and the residual area of ​​the ink, and improving the wear resistance.

[0078] (3) Example 11 By increasing the saturated water absorption rate of silicone rubber and making the residual rate of the monomer after hydrolysis of the organosilicon compound in the ink 87%, the affinity between silicone rubber and conductive ink is improved, and the adhesion of ink and the residual area of ​​ink are increased.

[0079] (4) In this invention, the content of hydrolyzable organosilicon compounds in the ink is important, while other components are arbitrary. Therefore, Table 1 shows the content based on... 29 The monomer residue rate in the ink (analysis results of changes in the content of organosilicon compounds before and after hydrolysis) was measured using Si-NMR. It was found that if the monomer residue rate of the hydrolyzable organosilicon compounds in the conductive ink coating layer is above 50%, the ink containing conductive fillers exhibits good adhesion and durability to silicone rubber.

[0080] (Examples 12-14, Comparative Example 3)

[0081] [Silicone Rubber Manufacturing Method]

[0082] 50g each of commercially available addition-curing liquid silicone polymers RBL9200-50A and RBL9200-50B (manufactured by Dow Toray, liquid silicone rubber raw materials; liquid A contains base polymer components and catalyst components, and liquid B contains base polymer components and crosslinking components) were weighed and mixed. After vacuum degassing, a single vulcanization was performed at 150°C for 10 minutes under pressure.

[0083] [Conductive ink coating]

[0084] Add 310 mL of solvent (hydrocarbon solvent: solvent S) to 40 g of commercially available conductive ink (PRK-3C: manufactured by Dow TORAY), and add the amounts of ion-exchanged water shown in Table 2. For example... Figure 1 As shown, the ink was applied to a silicone rubber surface in an area 15 mm long and 2 mm wide with a coating weight of 0.1 g. Then, it was subjected to two vulcanization processes at 200°C for 2 hours in a hot air circulating oven, simultaneously drying and sintering the ink.

[0085] The conditions and results are summarized in Appendix Table 2.

[0086] Table 2

[0087]

[0088] From Table 2, we can see that:

[0089] (1) In Examples 12-14, by adding a specified amount of water to the conductive ink, the residual rate of the monomers after hydrolysis of the organosilicon compounds in the ink is 52-76%, thereby improving the affinity between silicone rubber and conductive ink and increasing the residual area of ​​the ink.

[0090] (2) In Comparative Example 3, since no water was added to the conductive ink, the monomer residual rate of the organosilicon compound in the ink was 100%, so the affinity between silicone rubber and conductive ink was reduced and the residual area of ​​ink was reduced.

[0091] Industrial availability

[0092] The silicone rubber molded body of the present invention is suitable for use in switching functional elements, flexible circuits, and electrical contacts.

[0093] Symbol Explanation

[0094] 1 - Silicone rubber molded body

[0095] 2-Sheet

[0096] 3 - Conductive ink coating area

[0097] 4 - Contact portion of the wear wheel

[0098] 5 - Wear Testing Apparatus

[0099] 6 - Rotary Table

[0100] 7a, 7b - Friction wheels

[0101] 8-comb electrode

[0102] 9 - Contact Resistance Measurement Section

[0103] 10 - Clip-type lead fixing electrode

Claims

1. A molded body of silicone rubber, characterized by: It is a silicone rubber molded body with a conductive ink coating layer on any part of the surface of the silicone rubber molded body. The silicone rubber molded body is selected from at least one molded body of compounded silicone rubber molded body and addition-cured silicone rubber molded body, and does not contain linear dialkyl polysiloxane diol; The conductive ink coating layer contains a hydrolyzable organosilicon compound; The affinity between the surface of the silicone rubber molded body and the conductive ink coating layer is improved by selecting at least one of the following: specifying the saturated water absorption rate of the silicone rubber molded body to be 0.10 to 1.50% by mass and adding water to the conductive ink coating at a rate of 0.1 to 3.5 mol% relative to the hydrolyzable organosilicon compound. Using the JIS L1096 8.19.3C method, also known as the Taber method, the ink residue area on the surface of the conductive ink coating layer during the wear test was on average more than 20% and less than 100%.

2. The silicone rubber molded body according to claim 1, wherein, The hydrolyzable organosilicon compound is selected from at least one of methyl silicate, ethyl silicate, propyl silicate, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, methyltri(methoxyethoxy)silane, vinyltri(methoxyethoxy)silane, methyltripropenoxysilane, vinyltripropenoxysilane, methyltriacetoxysilane, vinyltriacetoxysilane, methyltri(acetone oxime)silane, vinyltri(acetone oxime)silane, methyltri(methyl ethyl ketone oxime)silane, and vinyltri(methyl ethyl ketone oxime)silane.

3. The silicone rubber molded body according to claim 1 or 2, wherein When the ink is set to 100% by mass, 5 to 30% by mass of the hydrolyzable organosilicon compound is added.

4. The silicone rubber molded body according to claim 1 or 2, wherein When the monomer residual rate of the hydrolyzable organosilicon compound in the conductive ink coating without added water is set to 100%, the monomer residual rate of the hydrolyzable organosilicon compound contained in the conductive ink coating layer is 45-95% by adding water to the conductive ink coating.

5. The silicone rubber molded body according to claim 1 or 2, wherein The silicone rubber molded body has surface adhesion, and the surface adhesion is measured according to JIS Z 0237, with an adhesion force of 1.5 to 3.0 gf·s.

6. The silicone rubber shaped body according to claim 1 or 2, wherein The contact resistance of the conductive ink coating layer is below 300Ω.

7. The silicone rubber shaped body according to claim 1 or 2, wherein The silicone rubber molded body is cured by organic peroxide.

8. A method for manufacturing a silicone rubber molded body, characterized in that: The method for manufacturing the silicone rubber molded body according to any one of claims 1 to 7. The saturated water absorption rate of the silicone rubber molded body is specified to be 0.10–1.50% by mass. An ink coating layer is formed by coating any portion of the surface of the silicone rubber molded body with a conductive ink containing a hydrolyzable organosilicon compound. A silicone rubber molded body is obtained, wherein the ink residue area of ​​the silicone rubber molded body is on average more than 20% and less than 100% when the surface of the conductive ink coating layer is worn using the JIS L1096 8.19.3C method, i.e., the Taber method.

9. A method for manufacturing a silicone rubber molded body, characterized in that: The method for manufacturing the silicone rubber molded body according to any one of claims 1 to 7. An ink coating layer is formed by coating any part of the surface of the silicone rubber molded body with a conductive ink containing 0.1 to 3.5 mol% water relative to the hydrolyzable organosilicon compound. A silicone rubber molded body is obtained, wherein the ink residue area of ​​the silicone rubber molded body is on average more than 20% and less than 100% when the surface of the conductive ink coating layer is worn using the JIS L1096 8.19.3C method, i.e., the Taber method.

10. The use of the silicone rubber molded article according to any one of claims 1 to 7, characterized in that: The silicone rubber molded body is used for switching functional elements, flexible circuits, or electrical contacts.

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