JP2006131770A - Conductive silicone material and conductive coating film - Google Patents

Abstract

【Task】
Conductive silicone material comprising an organopolysiloxane having an ion-conductive substituent, particularly good film-forming properties as a coating agent, excellent heat resistance, and little change in surface resistance over time And a conductive coating film made of the material.
[Solution]
Supplying a silane compound A having no mercapto group and a silane compound B having a mercapto group to a reaction system to advance cohydrolysis and polycondensation to obtain a sol solution of organopolysiloxane;
A step of drying and solidifying the sol solution to obtain a solidified product;
A conductive silicone material comprising an organopolysiloxane obtained by a method comprising a step of oxidizing a mercapto group of the solidified product, and a conductive coating film comprising the conductive silicone material.
[Selection figure] None

Description

  The present invention relates to a conductive silicone material made of an organopolysiloxane having an ion conductive substituent, and a conductive coating film made of the material.

  A perfluoroalkyl sulfonic acid membrane or the like is used as a membrane made of an ionic conductor or a polymer solid electrolyte, but this membrane has a problem of insufficient heat resistance. In order to solve this problem and obtain a film having improved heat resistance, it has been studied to use an organic-inorganic composite material. However, an organic-inorganic composite material suitable as a material for the film has not yet been developed. Not.

  Specifically, as a polymer solid electrolyte membrane made of an organic-inorganic composite material, for example, a product made of a reaction product obtained by graft-polymerizing polyethylene oxide methacrylate to methyl hydrogen silicone and an inorganic ion salt (patents) Document 1), which is obtained by impregnating a polymer obtained by polymerizing an alkyl (meth) acrylate in the presence of an organopolysiloxane with an organic electrolyte containing a lithium electrolyte salt (Patent Document 2) Has been proposed. However, these organic-inorganic composite materials have a problem that the compatibility between the organic component and the inorganic component is poor, and therefore, the production is difficult.

  Recently, a sol in which each component is uniformly mixed by adding alkoxysilane having a mercapto group later while hydrolyzing and polycondensing a specific silane compound, and continuing hydrolysis and polycondensation of these compounds. A composite material produced by oxidizing a mercapto group of a solidified product obtained by drying and solidifying the sol solution to a sulfonic acid group after obtaining the solution is also reported (Patent Document 3). This composite material has improved workability, compatibility, etc. to some extent, especially as a coating film is inferior in film formability, and there is a problem that the surface resistance value of the obtained film changes over time, It was inappropriate as a composite material used for a coating film.

JP-A 63-55810 JP-A-11-232925 Japanese Unexamined Patent Publication No. 2004-107597

  The present invention is a conductive silicone material comprising an organopolysiloxane having an ion conductive substituent, and particularly has good film-forming properties as a coating agent, excellent heat resistance, and little change in surface resistance over time. It is an object to provide a conductive silicone material and a conductive coating film made of the material.

The present invention firstly (i) general formula (1):
^{_{R m R 1 n Si (OR}} 2) 4-m-n (1)
(Wherein R is an unsubstituted monovalent hydrocarbon group, R ¹ is a substituted monovalent hydrocarbon group, R ² is an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, m is an integer of 0 to 2, n is 0 or 1, provided that m + n is an integer of 1 to 3)
Silane compound A having no mercapto group represented by the general formula (2):
HS-Y-Si (OR ³ ) _p R ⁴ _3-p (2)
Wherein Y is an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms, R ³ and R ⁴ are independently an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, and p is 2 or 3)
A step of supplying a silane compound B having a mercapto group represented by formula (1) to a reaction system and advancing cohydrolysis and polycondensation to obtain a sol solution of organopolysiloxane;
(ii) drying and solidifying the sol solution to obtain a solidified product;
(iii) a conductive silicone material comprising an organopolysiloxane obtained by a method comprising a step of oxidizing a mercapto group of the solidified product,
I will provide a.

In addition, the present invention secondly (I) average composition formula (3):
R ⁵ _q R ⁶ _r R ⁷ _s SiO _{{4- (q + r + s + t + u)} / 2} (OR ⁸ ) _t (OH) _u (3)
(Wherein R ⁵ is an unsubstituted monovalent hydrocarbon group, R ⁶ is a substituted monovalent hydrocarbon group, R ⁷ is of the formula HS-Y— (where Y is unsubstituted or substituted) R ⁸ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and q is a group having a mercapto group represented by: 0.5 ≦ q ≦ 1.8, r is a number 0 ≦ r ≦ 1.0, s is a number 0 <s ≦ 1.0, t is a number 0 <t ≦ 1.0, and u is 0 < u ≦ 1.0, where 0.5 ≦ q + r + s ≦ 1.8, 0 <t + u ≦ 1.0, and 0.5 <q + r + s + t + u ≦ 2.8)
A step of mixing an acid, a metal β-diketone complex, or a mixture thereof (hereinafter referred to as “acid or metal β-diketone complex”) with a silicone oligomer C having a mercapto group represented by:
(II) heating and solidifying the liquid mixture to obtain a solidified product;
(III) a conductive silicone material obtained by a method comprising a step of oxidizing a mercapto group of the solidified product,
I will provide a.

  Furthermore, the present invention thirdly provides a conductive coating film made of the conductive silicone material.

  The conductive silicone material of the present invention is a conductive silicone material composed of an organopolysiloxane having an ion conductive substituent, and particularly has good film-forming properties as a coating agent, and has ion conductivity, heat resistance and water resistance. It is a conductive silicone material that excels in workability, workability, etc. and has little change in surface resistance over time. This conductive silicone material is also useful for producing a conductive coating film.

[Conductive coating material]
The conductive coating material of the present invention usually has a surface resistance value measured by applying a voltage of 10 V under the conditions of a temperature of 25 ° C. and a relative humidity of 40% using a high resistivity meter or the like. It is less than ⁹ Ω, typically 1 × 10 ^{5 to} 5 × 10 ⁸ Ω. The conductive silicone material has a ratio A / A ₀ between the surface resistance value A ₀ immediately after production and the surface resistance value A after 10 days from production of 3 or less, preferably 0.5 to 2.5, The change in resistance value with time is small.

<Method 1 for producing conductive coating material>
For example, as described above, the conductive coating material of the present invention comprises (i) a reaction system comprising a silane compound A represented by the general formula (1) and a silane compound B represented by the general formula (2). A process of cohydrolysis and polycondensation to obtain an organopolysiloxane sol solution;
(ii) drying and solidifying the sol solution to obtain a solidified product;
(iii) oxidizing the mercapto group of the solidified product.

  Details of each step are as follows.

-Step (i)-
In step (i), the method of supplying the silane compound A and the silane compound B to the reaction system is not particularly limited as long as both silane compounds are supplied to the reaction system. For example, both silane compounds are mixed in advance. Alternatively, they may be supplied from separate supply means (for example, a supply tube connected to a reaction vessel or a reaction tube). In this case, both silane compounds may be supplied to the reaction system in any form such as dropping, jetting, spraying, inflow, or the like. In supplying the silane compound A and the silane compound B, care should be taken to minimize the time during which hydrolysis and / or polycondensation of either one of both compounds proceeds. Silane compound A and silane compound B are substantially hydrolyzed together and polycondensation needs to proceed.

  The cohydrolysis and polycondensation usually proceed in the presence of water and a hydrolysis catalyst. Both silane compounds may be supplied to the reaction system all at once, or a part of the silane compounds may be supplied to the reaction system, but the silane compound is uniformly mixed with water and the hydrolysis catalyst. And the hydrolysis and polycondensation proceed.

  The reaction system means a place where the silane compound A, the silane compound B, water and a hydrolysis catalyst are in contact with each other, and the co-hydrolysis and polycondensation of the silane compound are performed. Specific examples include, but are not limited to, batch-type reaction vessels, continuous reaction tubes and lines.

  As a specific example of the co-hydrolysis and polycondensation step, when batch processing is performed, both silane compounds are charged in a reaction vessel or the like in a single volume, and the two silane compounds are mixed with water and hydrolysis while stirring sufficiently. A method of adding a catalyst; a method in which water and a hydrolysis catalyst are charged in a reaction vessel or the like, and both silane compounds are mixed in advance or added separately with sufficient stirring. In the case of a continuous process, for example, in a continuous line process, a silane compound from a supply pipe or the like provided in the process (that is, a means for supplying water, hydrolysis catalyst, etc. from the supply means to the line) Examples thereof include a method of supplying A, silane compound B, water and a hydrolysis catalyst to the line in a form in which they are uniformly mixed in the line. For example, the silane compound A and the silane compound B are first supplied to the line, and the two silane compounds are sufficiently mixed in the process of passing through the line. For the silane compound in the state, water and a hydrolysis catalyst are supplied from a supply pipe or the like.

  The organopolysiloxane produced by the cohydrolysis and polycondensation is obtained in the form of a sol solution. In this sol solution, the concentration of the organopolysiloxane is preferably about 5 to 50% by mass, particularly about 10 to 30% by mass.

  Details of each component used in the step (i) are as follows.

・ Silane compound A
The silane compound A does not have a mercapto group represented by the general formula (1).

  In the general formula (1), R represents an unsubstituted monovalent hydrocarbon group, and the number of carbon atoms is usually 1 to 10, but preferably 1 to 6. Examples of the unsubstituted monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, hexyl group, cyclohexyl group, octyl group, and decyl group; An alkenyl group such as a vinyl group, an allyl group, a 5-hexenyl group, and a 9-decenyl group; an aryl group such as a phenyl group, and the like are preferable, and a methyl group, a propyl group, a hexyl group, and a phenyl group are preferable. In particular, when the properties required for the conductive silicone material are mainly weather resistant, a methyl group is preferable, and when it is water-repellent, a long chain (for example, 5 to 10 carbon atoms) alkyl group is preferable. In the case of flexibility, a phenyl group is preferred.

R ¹ represents a substituted monovalent hydrocarbon group, and the number of carbon atoms is usually 1 to 10, but preferably 1 to 3. As this substituted monovalent hydrocarbon group, for example, in the group exemplified as the unsubstituted monovalent hydrocarbon group represented by R, a part or all of the hydrogen atoms are substituted with the following substituents. Can be mentioned. The substituent is a mercapto group or a group having a mercapto group other than, for example, (i) a halogen atom such as fluorine or chlorine, (ii) an epoxy functional group such as a glycidyloxy group or an epoxycyclohexyl group, and (iii) methacrylic group. Groups, (meth) acrylic functional groups such as acrylic groups, (iv) amino functional groups such as amino groups, aminoethylamino groups, phenylamino groups, dibutylamino groups, (v) (polyoxyalkylene) alkyl ether groups, etc. Quaternary ammonium salt structures such as alkyl ether functional groups, (vi) anionic functional groups such as carboxyl groups and sulfonyl groups, and (vii) -N (CH ₃ ) ₃ X (wherein X represents a halogen atom) And the like. Specific examples of the substituted monovalent hydrocarbon group represented by R ¹ include a trifluoropropyl group, a perfluorobutylethyl group, a perfluorooctylethyl group, a 3-chloropropyl group, and 2- (chloromethylphenyl) ethyl. Group, 3-glycidyloxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 5,6-epoxyhexyl group, 9,10-epoxydecyl group, 3-acryloxypropyl group, 3-methacryloxy Propyl group, acryloxymethyl group, methacryloxymethyl group, 11-acryloxyundecyl group, 11-methacryloxyundecyl group, 3-aminopropyl group, N- (2-aminoethyl) aminopropyl group, 3- ( N-phenylamino) propyl group, 3-dibutylaminopropyl group, 3-mercaptopropyl group, 2- (4-mer Captomethylphenyl) ethyl group, polyoxyethyleneoxypropyl group, 3-hydroxycarbonylpropyl group, 3-tributylammoniumpropyl group and the like can be mentioned. In particular, an epoxy functional group, an amino functional group, or the like is preferable when the adhesion between the conductive coating film made of a conductive silicone material and the substrate is further improved. When a vinyl polymer is contained in the conductive silicone material, and the silane compound is more closely blocked with the vinyl polymer in the composition, a (meth) acryl capable of radical copolymerization is possible. Functional groups are preferred. In addition, when the silane compound is crosslinked with a bond other than the vinyl polymer and the siloxane bond, a functional group capable of reacting with a functional group contained in the vinyl polymer is preferable. Specifically, for example, an epoxy group (For example, it reacts with a functional group such as a hydroxy group, an amino group, or a carboxy group), an amino group (for example, reacts with a functional group such as an epoxy group or an acid anhydride group), and the like.

R ² represents an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group, and a methyl group and an ethyl group are preferable.

  Examples of the silane compound A include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, Phenyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyl Diethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyl Methyl diethoxy silane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, and the like.

  These silane compounds A may be used individually by 1 type, or may use 2 or more types together.

・ Silane compound B
The silane compound B has a mercapto group represented by the general formula (2).

  In the general formula (2), Y represents an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentene group.

R ³ and R ⁴ independently represent an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms. Examples of this alkyl group include those exemplified for R ² .

  Examples of the silane compound B include γ-mercaptopropylmethyldimethoxysilane, γ-mercaptoethylmethyldimethoxysilane, γ-mercaptomethylmethyldimethoxysilane, γ-mercaptopropylethyldiethoxysilane, and γ-mercaptoethylethyldiethoxysilane. , Γ-mercaptomethylethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopentyltriethoxysilane, γ-mercaptopentyltrimethoxysilane, etc., preferably γ -Mercaptopropyltrimethoxysilane.

  These silane compounds B may be used alone or in combination of two or more.

  Although the usage-amount of the said silane compound B is not specifically limited, Preferably it is 1-10 mass parts with respect to the said silane compound A10 mass parts. When this range is satisfied, it is easy to prepare a uniform and stable sol solution, and it is easy to obtain a uniform conductive silicone material having high electrical conductivity. Moreover, since the preparation of a uniform and stable sol solution becomes easier and the water resistance and heat resistance of the conductive silicone material are improved, the amount of the silane compound B used is more preferably 1 to 8 parts by mass. Furthermore, since water resistance and heat resistance are remarkably improved and sufficiently high electric conductivity is obtained, the amount of the silane compound B used is particularly preferably 1.5 to 6 parts by mass.

  Cohydrolysis and polycondensation may be carried out in an organic solvent or without using an organic solvent. The organic solvent is preferably a hydrophilic organic solvent, and examples thereof include alcohols such as methanol, ethanol, n-propanol, and isopropanol, or mixtures thereof. The total concentration of silane compound A and silane compound B in the reaction solution may be 15 to 100% by mass. In addition, the silane compound A and the silane compound B are preferably supplied to the reaction system after being dissolved in these hydrophilic organic solvents. Among these, methanol is preferable because the amount of water added can be reduced and the drying time can be shortened when the sol solution is dried to obtain a solidified product in step (ii) described later.

Hydrolysis catalyst / water The hydrolysis catalyst used in the co-hydrolysis and polycondensation is not particularly limited, and a known catalyst that has been conventionally used as a hydrolysis catalyst for a hydrolyzable silane compound may be used. Examples thereof include inorganic acids such as hydrochloric acid, nitric acid and sulfuric acid; organic acids such as acetic acid, monochloroacetic acid and p-toluenesulfonic acid; and metal β-diketone complexes such as acetylacetonatoaluminum.

In addition to these, as the hydrolysis catalyst, in addition to the action of promoting cohydrolysis and polycondensation, it also serves as a proton source and has the action of reducing the surface resistance value of the conductive silicone material, so phosphorous acid, Phosphorus compounds such as phosphoric acid, phosphite, and phosphoric acid esters; organic acids with low solubility in water such as oleic acid and stearic acid; elution from the three-dimensional network structure of organopolysiloxane that constitutes the conductive silicone material Polymer compounds such as diethyl phosphate triethoxysilane having a proton acid site that is difficult to form (ie, a site capable of donating protons); solid acids that are physically interacted and retained in the three-dimensional network structure are also suitable. Used for. Examples of the solid acid include α-Zr (HPO ₄ ) ₂ .nH ₂ O, γ-Zr (PO ₄ ) (H ₂ PO ₄ ) .2H ₂ O, SnO ₂ .2H ₂ O, Sb ₂ O _5. Examples thereof include hydrated oxides such as 5.4H ₂ O, and heteropolyacids such as H ₄ SiW ₁₂ O ₄₀ · nH ₂ O and H ₃ PW ₁₂ O ₄₀ · nH ₂ O. Among these, phosphorous acid, phosphoric acid, phosphoric acid methyl ester, phosphoric acid propyl ester, phosphoric acid dodecyl ester, phosphoric acid phenyl ester, phosphoric acid dimethyl ester, phosphoric acid dododecyl ester and the like having 1 to 30 carbon atoms Phosphorus compounds such as phosphites having 1 to 30 carbon atoms, such as phosphate esters, phosphite methyl esters, phosphite dodecyl esters, phosphite diethyl esters, diisopropyl phosphites, phosphite didodecyl esters, etc. A perfluorocarbon sulfonic acid polymer represented by Nafion (registered trademark), polyacrylates and polymethacrylates having a phosphate group in the side chain of the molecular chain (see JP 2001-114834 A), sulfonated polyether ether ketone (special No. 6-93111), sulfonated polyethersulfone (Japanese Patent Laid-Open No. 10-459) 13), sulfonated polysulfone (see JP-A-9-245818) and the like, sulfonated products of heat-resistant aromatic polymers and the like, polymer compounds having proton acid sites, tungstophosphoric acid, tungsten peroxo complexes, etc. A solid acid or the like is particularly preferable.

  These hydrolysis catalysts may be used alone or in combination of two or more.

  The amount of the hydrolysis catalyst used may be an effective amount, and is preferably 0.01 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the silane compound A and the silane compound B. With appropriate catalyst amount, co-hydrolysis and polycondensation proceed properly, and when making conductive coating film from conductive silicone material, not only film formation is performed well, but also sufficient pot life is ensured it can.

  Further, the amount of water used is not particularly limited as long as cohydrolysis and polycondensation are sufficiently advanced. Usually, the amount of water used is 5 to 100 with respect to 100 parts by mass in total of silane compound A and silane compound B. It is a mass part, Preferably it is 10-50 mass parts.

  After the completion of the cohydrolysis and polycondensation, a compound serving as the proton source may be added to the reaction system to impart or improve proton conductivity.

-Step (ii)-
In step (ii), the sol solution obtained in step (i) is preferably dried at 60 to 150 ° C. to obtain a solidified product. In this drying, not only the solvent in the sol solution is distilled off, but also a curing reaction proceeds by condensation of the alkoxy groups remaining in the produced organopolysiloxane.

-Step (iii)-
In the step (iii), a conductive silicone material is obtained by oxidizing the mercapto group of the solidified product obtained in the step (ii). The mercapto group is a sulfonic acid by, for example, an oxo acid such as hydrogen peroxide or nitric acid, an oxidizing agent such as permanganic acid, FeCl ₃ , CuO, or concentrated sulfuric acid, preferably a hydrogen peroxide solution diluted to a concentration of 15% by mass. What is necessary is just to oxidize to functional groups which have ion conductivity, such as a group. Specifically, as described above, after a solidified product such as a film is produced from the sol solution, the solidified product can be immersed in a solution containing the oxidizing agent, for example.

  The organopolysiloxane constituting the conductive silicone material obtained by the above steps is usually composed of a three-dimensional network structure.

<Method 2 for producing conductive coating material>
The conductive coating material of the present invention is, for example, as described above,
(I) a step of mixing an acid or a metal β-diketone complex with the silicone oligomer C represented by the average composition formula (3) to obtain a liquid mixture;
(II) heating and solidifying the liquid mixture to obtain a solidified product;
(III) It can also be produced by a method comprising a step of oxidizing the mercapto group of the solidified product.

  Details of each step are as follows.

-Process (I)-
In the step (I), the method of mixing the silicone oligomer C with an acid or a metal β-diketone complex is not particularly limited. Mixing can be performed either batchwise or continuously. For example, a reaction vessel, a reaction tube, a line, or the like is used. More specifically, a batch type reaction vessel, a continuous type reaction tube and a line can be mentioned. Further, the silicone oligomer C and the acid or metal β-diketone complex may be supplied to the mixing place by any form such as dripping, jetting, spraying, inflowing or the like. In this supply, the silicone oligomer C and the acid or metal β-diketone complex are all dissolved in an alcohol such as methanol, ethanol, n-propanol and isopropanol, or a solvent such as water, even if they are as they are. It may be in the state.

  As a specific example of the step (I), when batch processing is performed, a method in which a silicone oligomer and an acid or a metal β-diketone complex are charged into a reaction vessel or the like and sufficiently stirred can be mentioned. In the case of a continuous process, for example, in a continuous line process, the silicone oligomer C and the acid or metal β-diketone complex are uniformly mixed in the line from a supply pipe provided in the process. The method of supplying is mentioned. The form uniformly mixed in this line means that, for example, the silicone oligomer C and the acid or metal β-diketone complex are sufficiently mixed in the course of flowing through the line. A liquid mixture is obtained by mixing these silicone oligomer C and acid or metal β-diketone complex.

  Details of each component used in the step (I) are as follows.

・ Silicone oligomer C
The silicone oligomer C has a mercapto group represented by the average composition formula (3). The silicone oligomer C may be produced by any method, but can be easily produced by cohydrolyzing and polycondensing the silane compound A and the silane compound B.

In the average composition formula (3), R ⁵ represents an unsubstituted monovalent hydrocarbon group, and the number of carbon atoms is usually 1 to 10, preferably 1 to 6. Examples of the unsubstituted monovalent hydrocarbon group include those exemplified for R.

R ⁶ represents a substituted monovalent hydrocarbon group, and the number of carbon atoms is usually 1 to 10, but preferably 1 to 3. Examples of the substituted monovalent hydrocarbon group include those exemplified for R ¹ .

R ⁷ represents a group having a mercapto group represented by the formula: HS—Y— (wherein Y is as defined above). The group having a mercapto group is not particularly limited, and examples thereof include γ-mercaptopropyl group, γ-mercaptoethyl group, γ-mercaptomethyl group, γ-mercaptopentyl group, and preferably γ-mercaptopropyl group. It is a group.

R ⁸ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6, preferably 1 to 3 carbon atoms. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group and hexyl group; alkenyl groups such as allyl group and vinyl group; phenyl group and the like. An aryl group etc. are mentioned.

OR ⁸ group represents a hydrolyzable group, and specific examples thereof include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, t-butoxy group, isopropenoxy group, phenoxy group and the like. And hydrocarbyloxy groups. Among these, a methoxy group, an ethoxy group, and an isopropoxy group are preferable because the reactivity of cohydrolysis and polycondensation and the stability in an emulsion are good.

q is a number satisfying 0.5 ≦ q ≦ 1.8, preferably 0.6 ≦ q ≦ 1.8. When q is less than 0.5, the content of R ^{5 in} the average composition formula (3) is low, the conductive silicone material becomes too hard, and cracks are likely to occur. When q exceeds 1.8, the content of chain units in the formula is high, the conductive silicone material is rubbery, and the scratch resistance may be inferior.

r is a number satisfying 0 ≦ r ≦ 1.0. When r exceeds 1.0, the bulky R ⁶ content in the above average composition formula (3) becomes high, it is difficult to maintain the hardness of the conductive silicone material, and the weather resistance also decreases. There is.

s is a number 0 <s ≦ 1.0, and preferably 0.01 ≦ s ≦ 0.9. When s exceeds 1.0, the bulky R ⁶ content in the above average composition formula (3) becomes high, it is difficult to maintain the hardness of the conductive silicone material, and the weather resistance also decreases. There is. In addition, since it is essential to have a mercapto group in the formula in order to reduce the surface resistance value of the conductive silicone material, s must exceed 0.

  t is a number satisfying 0 <t ≦ 1.0, preferably a number satisfying 0.05 ≦ t ≦ 0.8, and more preferably a number satisfying 0.2 ≦ t ≦ 0.7. When t exceeds 1.0, the hydrocarbyloxy group in the conductive silicone material reacts with time and may be inferior in terms of stability.

  u is a number 0 <u ≦ 1.0, preferably 0.05 ≦ u ≦ 0.8, more preferably 0.2 ≦ u ≦ 0.7. When u exceeds 1.0, silanol groups in the conductive silicone material react with time and may be inferior in terms of stability.

  These q, r, s, t, and u are numbers satisfying 0.5 ≦ q + r + s ≦ 1.8, and it is essential that 0 <t + u ≦ 1.0. When q + r + s is less than 0.5, the conductive silicone material becomes too hard and cracks are likely to occur. When q + r + s exceeds 1.8, the conductive silicone material may be rubbery and have poor scratch resistance. Moreover, it is essential that t + u representing the total number of crosslinkable substituents is a number satisfying the range of 0 <t + u ≦ 1.0. When t + u is 0, the conductive silicone material is not cured, and when it exceeds 1.0, the molecules constituting the silicone material become small and water-soluble, which is not preferable. Furthermore, q + r + s + t + u must be a number of 0.5 <q + r + s + t + u ≦ 2.8, and preferably a number of 0.6 ≦ q + r + s + t + u ≦ 2.5.

  These silicone oligomers C may be used alone or in combination of two or more.

  The mixing of the silicone oligomer C and the acid or metal β-diketone complex is usually performed only with these two components, but may be performed in a solvent as necessary. The solvent is preferably a hydrophilic organic solvent, and examples thereof include alcohols such as methanol, ethanol, n-propanol, and isopropanol, or mixtures thereof. Among these, methanol is preferable because the drying time can be shortened when the solid mixture is obtained by heating the liquid mixture in the step (II) described later.

Acid or metal β diketone complex The acid or metal β diketone complex is an acid, a metal β diketone complex, or a mixture thereof, as described above. Here, specific examples of the acid include acids in the compounds exemplified above as the hydrolysis catalyst. The acid or metal β diketone complex may be used alone or in combination of two or more.

  The amount of the acid or metal β-diketone complex used is not particularly limited, but is preferably 0.01 to 10 parts by mass, particularly preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the silicone oligomer C. When this range is satisfied, when a conductive coating film is produced from a conductive silicone material, not only film formation is performed well, but a sufficient pot life can be secured.

  In addition, you may use separately the compound used as the proton source demonstrated regarding the manufacturing method 1 with said acid or metal beta diketone complex as needed.

-Process (II)-
In step (II), the liquid mixture obtained in step (I) is preferably heated at 60 to 150 ° C. to obtain a solidified product.

-Process (III)-
In step (III), a conductive silicone material is obtained in the same manner as in step (iii) except that the solidified product obtained in step (II) is used.

[Use of conductive silicone materials]
The conductive silicone material of the present invention is preferably used for applications such as a conductive coating film in fields such as liquid crystal, organic EL, PDP and other displays, and dust adhesion prevention on the touch panel surface.

[Method for producing conductive coating film]
When producing a conductive coating film, which is a suitable application of the conductive silicone material, the production method is not particularly limited. For example, the obtained sol solution or liquid mixture is used, for example, a doctor blade, a bar coater, or the like. Use it on a substrate (support) made of a material such as a Teflon (registered trademark) sheet, polyethylene terephthalate film, or glass plate, or pour it thinly into a shallow mold made of these materials at room temperature (for example, 25 ° C.) It may be air-dried or heated gently (eg, 80 ° C.) and dried. The thickness of the conductive coating film varies depending on the application, but is usually 0.01 to 100 μm, particularly 0.1 to 50 μm in a dry state.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example, this invention is not limited to these Examples at all. In the examples, “parts” represents parts by mass.

<Example 1>
89 parts of tetraethoxysilane (Shin-Etsu Chemical Co., Ltd.), 38 parts of phenyltriethoxysilane (Shin-Etsu Chemical Co., Ltd.), 38 parts of γ-mercaptopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.), and methanol 224 The parts were mixed. To this mixed solution, 35 parts of water and an amount of 0.2 part of 85 mass% phosphoric acid aqueous solution as phosphoric acid were added, and stirring was continued at room temperature for 1 day. The resulting solution was applied onto a glass plate with a bar coater (No. 20). Thereafter, the coating film on the glass plate was cured by heating at 80 ° C. for 1 hour, and allowed to stand in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 1 day to prepare a coating film. This coating film was immersed in 15% by mass hydrogen peroxide for 14 hours, oxidized, washed with water, and air-dried in a constant temperature and humidity room at 25 ° C. and a relative humidity of 50% for 1 day. The surface resistance value of the obtained oxidation-treated coating film was measured according to the following measurement method. The results are shown in Table 1.

・ Measurement method of surface resistance value Using a high resistivity meter (trade name: Hiresta-Up MODEL MCP-HT450, manufactured by Mitsubishi Chemical Corporation), applied voltage in a constant temperature and humidity chamber at 25 ° C and relative humidity of 40% Was 10 V, and the surface resistance value (initial) A ₀ of the coating film immediately after production was measured. In addition, the coating film was stored for 10 days in an environment of 25 ° C. and a relative humidity of 50%, and then the surface resistance value A of the coating film was measured.

<Example 2>
In Example 1, an oxidation-treated coating film was produced in the same manner as in Example 1 except that 1 part nitric acid aqueous solution was used instead of phosphoric acid in an amount of 0.2 part as nitric acid, and the surface resistance value was measured. The results are shown in Table 1.

<Example 3>
In Example 1, except that the amount of 85 mass% phosphoric acid aqueous solution was changed from 0.2 parts to 1.7 parts as phosphoric acid, an oxidation-treated coating film was prepared and the surface resistance value was measured. did. The results are shown in Table 1.

<Example 4>
52 parts of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 55 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 216 parts of methanol were mixed. To this mixed solution, 25 parts of water and an amount of 1.1 parts of 85 mass% phosphoric acid aqueous solution as phosphoric acid were added, and stirring was continued at room temperature for 1 day. Thereafter, using the obtained solution, an oxidation-treated coating film was produced in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

<Example 5>
771 parts of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 371 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), and 148 parts of methanol were mixed. To this mixed solution, a mixed solution of 79 parts of 0.05N hydrochloric acid and 296 parts of methanol was added dropwise at room temperature over 1 hour. This solution was aged for 2 hours under reflux of methanol at 70 ° C., and then 75 parts of a 1 mass% sodium acetate-methanol solution was added to the solution, and further aged for 2 hours at the same temperature. An ester adapter equipped with a serpentine cooler was attached and heated in an oil bath, and the solvent was distilled off until the internal temperature reached 120 ° C. to obtain a silicone oligomer.
To 100 parts of this silicone oligomer, an amount of 1 part of 85 mass% phosphoric acid aqueous solution as phosphoric acid was added and shaken for 30 minutes. Then, using the obtained liquid mixture, an oxidation treatment coating film was produced in the same manner as in Example 1, and the surface resistance value was measured. The results are shown in Table 1.

<Comparative Example 1>
89 parts of tetraethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 48 parts of methanol were mixed. To this mixed solution, 8 parts of water and 0.2 parts of 1M nitric acid aqueous solution as nitric acid were added, and stirring was continued at room temperature for 1 hour. To the obtained mixed solution, 38 parts of phenyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 66 parts of methanol were mixed and added, and stirred for about 30 minutes. Thereafter, 38 parts of γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 110 parts of methanol and 27 parts of water were added to this solution, and stirring was continued at room temperature for 1 day. The resulting solution was applied on a glass plate with a bar coater (No. 20). Thereafter, the coating film on the glass plate was cured by heating at 80 ° C. for 1 hour, and allowed to stand in a constant temperature and humidity chamber at 25 ° C. and a relative humidity of 50% for 1 day to prepare a coating film. The surface resistance value of this film was measured according to the measurement method described above. The results are shown in Table 1.

<Comparative example 2>
The coating film prepared in Comparative Example 1 was immersed in 15% by mass hydrogen peroxide for 14 hours, oxidized, then washed with water, and air-dried in a constant temperature and humidity room at 25 ° C. and 50% relative humidity for 1 day. did. The surface resistance value of the oxidation-treated coating film was measured according to the measurement method described above. The results are shown in Table 1.

<Comparative Example 3>
In Comparative Example 2, an oxidation treatment coating film was prepared in the same manner as in Comparative Example 2 except that 85 parts by mass of phosphoric acid aqueous solution instead of nitric acid was used in an amount of 0.2 part as phosphoric acid. It was measured. The results are shown in Table 1.

note)
-The unit of use amount of each component in the table is "part by mass".
・ "Nitric acid" in the table is the amount of nitric acid in 1M nitric acid aqueous solution, "phosphoric acid" is the amount of phosphoric acid in 85 mass% phosphoric acid aqueous solution, and "water" is 1M nitric acid aqueous solution or phosphoric acid aqueous solution It is the amount of water attached separately from the water contained therein.

<Evaluation>
As is clear from Comparative Example 1, the surface resistance value exceeds 10 ¹⁰ Ω simply by adding silane compounds sequentially and hydrolyzing. Further, as is clear from Comparative Examples 2 and 3, when mercaptosilane was added later even after the oxidation treatment, a good surface resistance value was exhibited immediately after the production of the coating film (initial). After 10 days, the value is 5 times or more, and the change with time is remarkable.
On the other hand, in the example satisfying the requirements of claim 1 or 3 of the present invention, the surface resistance value A ₀ immediately after the production of the coating film is as good as 8.0 × 10 ⁷ Ω or less, and 10 days after the production of the coating film. The surface resistance value A is 2.1 × 10 ⁸ Ω or less, and changes slightly compared to the surface resistance value A ₀ immediately after manufacture, but the ratio A / A ₀ is 3 or less, so it is relatively stable over time. It is.

Claims (8)

(i) General formula (1):
^{_{R m R 1 n Si (OR}} 2) 4-m-n (1)
(Wherein R is an unsubstituted monovalent hydrocarbon group, R ¹ is a substituted monovalent hydrocarbon group, R ² is an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, m is an integer of 0 to 2, n is 0 or 1, provided that m + n is an integer of 1 to 3)
Silane compound A having no mercapto group represented by the general formula (2):
HS-Y-Si (OR ³ ) _p R ⁴ _3-p (2)
Wherein Y is an unsubstituted or substituted alkylene group having 1 to 5 carbon atoms, R ³ and R ⁴ are independently an unsubstituted or substituted alkyl group having 1 to 3 carbon atoms, and p is 2 or 3)
A step of supplying a silane compound B having a mercapto group represented by formula (1) to a reaction system and advancing cohydrolysis and polycondensation to obtain a sol solution of organopolysiloxane;
(ii) drying and solidifying the sol solution to obtain a solidified product;
(iii) A conductive silicone material comprising an organopolysiloxane obtained by a method comprising a step of oxidizing a mercapto group of the solidified product.   The conductive silicone material according to claim 1, wherein the amount of the silane compound B is 1 to 10 parts by mass with respect to 10 parts by mass of the silane compound A. (I) Average composition formula (3):
R ⁵ _q R ⁶ _r R ⁷ _s SiO _{{4- (q + r + s + t + u)} / 2} (OR ⁸ ) _t (OH) _u (3)
(Wherein R ⁵ is an unsubstituted monovalent hydrocarbon group, R ⁶ is a substituted monovalent hydrocarbon group, R ⁷ is of the formula HS-Y— (where Y is unsubstituted or substituted) R ⁸ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and q is a group having a mercapto group represented by: , 0.5 ≦ q ≦ 1.8, r is a number 0 ≦ r ≦ 1.0, s is a number 0 <s ≦ 1.0, t is a number 0 <t ≦ 1.0, and u is 0 <Number of u ≦ 1.0, where 0.5 ≦ q + r + s ≦ 1.8, 0 <t + u ≦ 1.0, and 0.5 <q + r + s + t + u ≦ 2.8)
A step of mixing an acid, a metal β-diketone complex, or a mixture thereof with the silicone oligomer C having a mercapto group represented by
(II) heating and solidifying the liquid mixture to obtain a solidified product;
(III) A conductive silicone material obtained by a method comprising a step of oxidizing a mercapto group of the solidified product.   The conductive silicone material according to claim 3, wherein the silicone oligomer C is obtained by cohydrolysis and polycondensation of the silane compound A and the silane compound B according to claim 1.   The conductive silicone material according to any one of claims 1 to 4, wherein the step of oxidizing the mercapto group of the solidified product includes a step of bringing the solidified product and hydrogen peroxide solution into contact with each other. The ratio A / A ₀ between the surface resistance value A ₀ immediately after the production of the conductive silicone material and the surface resistance value A after 10 days from the production is 3 or less, the conductivity according to any one of claims 1 to 5. Silicone material. The conductive silicone material according to any one of claims 1 to 6, wherein a surface resistance value measured by applying a voltage of 10 V under conditions of a temperature of 25 ° C and a relative humidity of 40% is less than 1 x 10 ⁹ Ω. .   A conductive coating film comprising the conductive silicone material according to claim 1.