Curable polyorganosiloxane composition

Abstract

To provide a curable silicone composition excellent in salt water resistance and uniformity, and a compound capable of imparting excellent salt water resistance and uniformity to the curable silicone composition.SOLUTION: The present invention relates to a curable polyorganosiloxane composition containing (A) a polyorganosiloxane having two or more hydrolyzable groups bonded to a silicon atom in one molecule, (B) a curing catalyst, and (C) a compound containing a mercaptobenzothiazolyl group and one or more selected from the group consisting of a hydrolyzable group bonded to a silicon atom and a siloxane chain in one molecule, and the component (C).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to curable polyorganosiloxane compositions. [Background technology]

[0002] Among polyorganosiloxane compositions that harden at room temperature to form a rubber-like elastomer, those that undergo a hardening reaction upon contact with moisture in the air eliminate the hassle of weighing and mixing the main body (base polymer), crosslinking agent, catalyst, etc. immediately before use, and are free of the risk of compounding errors.In addition, they have excellent adhesive properties, so they are widely used as coating materials for the electrical and electronics industries, as well as sealing materials for construction.

[0003] As electrodes and wiring in LCDs (Liquid Display Panels) and PDPs (Plasma Display Panels) become increasingly miniaturized, there is a growing demand for coating materials that are effective in preventing corrosion and migration of electrodes and wiring.

[0004] As such a coating material, Patent Document 1 describes a room-temperature curable polyorganosiloxane composition containing 1,2,4-triazole or a derivative thereof. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-206817 Summary of the Invention [Problem to be solved by the invention]

[0006] The room-temperature-curable polyorganosiloxane composition containing 1,2,4-triazole described in Patent Document 1 has problems such as poor uniformity of the composition and poor saltwater resistance of the resulting coating.

[0007] An object of the present invention is to provide a curable silicone composition that has excellent saltwater resistance and excellent uniformity. Another object of the present invention is to provide a compound that can impart excellent saltwater resistance and uniformity to a curable silicone composition. [Means for solving the problem]

[0008] That is, the present invention relates to the following [1] to [9]. [1] (A) a polyorganosiloxane having two or more hydrolyzable groups bonded to silicon atoms in one molecule; (B) a curing catalyst, and (C) A compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one member selected from the group consisting of a hydrolyzable group and a siloxane chain bonded to a silicon atom. 1. A curable polyorganosiloxane composition comprising: [2] The curable polyorganosiloxane composition according to [1], wherein component (C) is a compound containing one or two mercaptobenzothiazolyl groups, a siloxane chain, and a hydrolyzable group bonded to a silicon atom in one molecule. [3] The component (C) is represented by the following general formula (1), (2), or (3): [ka] [During the ceremony, A 1 is expressed as equation (4): [ka] is a group represented by X 1 is an alkylene group which may be interrupted by -S- or a linear or cyclic siloxane chain; R 1 are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R 1 is a hydrolyzable group. [ka] [During the ceremony, A 2 and A 3 is a group represented by formula (4), X 2 and X 3 are each independently an alkylene group which may be interrupted by -S- or a linear or cyclic siloxane chain; R 2 are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R 2 is a hydrolyzable group, R 3 are each independently a hydrocarbon group, L 1 is 0 or a number between 1 and 1,000. [ka] [During the ceremony, A 4 is a group represented by formula (4), X 4 and X 5 are each independently an alkylene group which may be interrupted by -S- or a linear siloxane chain; R 4 are each independently a hydrocarbon group, R 5 are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R 5 is a hydrolyzable group, a is an integer of 1 or greater, and when a is an integer of 2 or greater, each A 4 , X 4 and R 4 are the same or different, b is an integer of 0 or 1 or more, and when b is an integer of 2 or more, each X 4 , R 4 and R 5 are the same or different, c is an integer of 0 or 1 or more, and when c is an integer of 2 or more, each R 4are the same or different, a+b+c is an integer of 3 or more]. The curable polyorganosiloxane composition according to [1] or [2]. [4] The curable polyorganosiloxane composition according to any one of [1] to [3], further comprising one or more selected from the group consisting of (D) a crosslinking agent, (E) an adhesion promoter, and (F) a polyorganosiloxane having no silicon-bonded hydrolyzable groups. [5] A coating agent for electronic parts, which uses the curable polyorganosiloxane composition according to any one of [1] to [4]. [6] A metal surface treatment agent using the curable polyorganosiloxane composition according to any one of [1] to [4]. [7] A cured product obtained by curing the curable polyorganosiloxane composition according to any one of [1] to [4]. [8] An electronic part comprising the curable polyorganosiloxane composition according to any one of [1] to [4]. [9] (C) A compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one member selected from the group consisting of a hydrolyzable group bonded to a silicon atom and a siloxane chain. [Effects of the Invention]

[0009] The present invention provides a curable silicone composition that exhibits excellent saltwater resistance and uniformity. The present invention also provides a compound that can impart excellent saltwater resistance and uniformity to a curable silicone composition. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Term definition] The structural units of siloxane compounds are sometimes abbreviated as follows (hereinafter, these structural units are referred to as "M units" and "D units" respectively). H (sometimes called "units"). M :(CH3)3SiO 1 / 2 M H:(CH3)2HSiO 1 / 2 M V :(CH3)2(CH2=CH)SiO 1 / 2 D :(CH3)2SiO 2 / 2 D H :(CH3)HSiO 2 / 2 D V :(CH3)(CH2=CH)SiO 2 / 2 T :CH3SiO 3 / 2 Q :SiO 4 / 2 (tetrafunctional)

[0011] In this specification, the use of "to" to indicate a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0012] In this specification, the viscosity is a value measured in accordance with JIS K 6249 using a rotational viscometer with an appropriate spindle number and rotation speed at 23°C. Specifically, the value is measured under the conditions described in the examples.

[0013] In this specification, "(A) a polyorganosiloxane having two or more silicon-bonded hydrolyzable groups per molecule" is also referred to as "component (A)." The same applies to "(B) a curing catalyst," etc.

[0014] As used herein, the term "hydrocarbon group" refers to a group containing carbon atoms and hydrogen atoms, with at least one hydrogen atom removed from the molecule. The hydrocarbon group may be substituted with one or more substituents. Examples of the substituents include halogen atoms and cyano groups.

[0015] Examples of the monovalent hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Examples of the monovalent hydrocarbon group having no aliphatic unsaturated bond include the above-mentioned monovalent hydrocarbon groups other than an alkenyl group.

[0016] The alkyl group is a linear or branched group having 1 to 18 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a hexadecyl group, and an octadecyl group. The cycloalkyl group is a monocyclic or polycyclic group having 3 to 20 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The aryl group is an aromatic group containing a monocyclic or polycyclic group having 6 to 20 carbon atoms, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. The aralkyl group is an alkyl group substituted with an aryl group, and examples thereof include a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group. The alkenyl group is a straight-chain or branched group having 2 to 6 carbon atoms, and examples thereof include a vinyl group, an allyl group, a propenyl group, a 3-butenyl group, and a 5-hexenyl group.

[0017] The alkenyl group, alkyl group, cycloalkyl group, aryl group, and aralkyl group may be substituted with a halogen or a cyano group. Examples of alkyl groups substituted with a halogen include a chloromethyl group, a bromoethyl group, a chloropropyl group, a 3,3,3-trifluoropropyl group, and a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group. Examples of aryl groups substituted with a halogen include a chlorophenyl group. Examples of alkyl groups substituted with a cyano group include a 2-cyanoethyl group.

[0018] The divalent hydrocarbon group is a group obtained by removing one hydrogen atom from the above-mentioned monovalent hydrocarbon group. The divalent hydrocarbon group is preferably an alkylene group. The alkylene group is a linear or branched group having 1 to 18 carbon atoms, and examples thereof include a methylene group, an ethylene group, a trimethylene group, a 2-methylethylene group, and a tetramethylene group.

[0019] [Curable Polyorganosiloxane Composition] The curable polyorganosiloxane composition (hereinafter also simply referred to as "composition") is The composition comprises (A) a polyorganosiloxane having two or more silicon-bonded hydrolyzable groups per molecule, (B) a curing catalyst, and (C) a compound having, per molecule, a mercaptobenzothiazolyl group and one or more members selected from the group consisting of silicon-bonded hydrolyzable groups and siloxane chains.

[0020] The composition has excellent salt water resistance and uniformity, as well as excellent heat resistance and reliability (heat cycle resistance).

[0021] [(A) Polyorganosiloxane having two or more silicon-bonded hydrolyzable groups per molecule] Component (A) is a polyorganosiloxane having two or more silicon-bonded hydrolyzable groups per molecule, and serves as the base polymer in the composition.

[0022] <Hydrolyzable group> Examples of hydrolyzable groups include -OR', -OCOR', -ON=CR'2, -NR'2, -NHR', halogen atoms, etc. In these formulas, R' is an alkyl group.

[0023] The hydrolyzable group is preferably -OR' (i.e., an alkoxy group). R' is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, more preferably an unsubstituted alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group or an ethyl group. Therefore, the hydrolyzable group is particularly preferably a methoxy group or an ethoxy group.

[0024] <Structure of component (A)> The structure of component (A) is not particularly limited as long as it has an average of two or more hydrolyzable groups bonded to silicon atoms per molecule. Component (A) is typically represented by general formula (5): (R a ) s (R 6 ) t SiO (4-s-t) / 2 (5) (In the formula, R a is a hydrolyzable group; R 6 is a monovalent hydrocarbon group having no aliphatic unsaturated bonds; s is an integer from 1 to 3; t is an integer of 0 to 2, provided that s+t is 1 to 3. The molecule has at least two units represented by the formula:

[0025] Component (A) is represented by the following general formula (6): (R a ) 3-p R 6 p Si-O-(Si(R 6 ) r (R a ) 2-r O) n -SiR 6 q (R a ) 3-q ···(6) (In the formula, R a are each independently a hydrolyzable group, R 6are each independently a monovalent hydrocarbon group having no aliphatic unsaturated bonds, p and q are each independently 0, 1, or 2; Each r is independently 0, 1, or 2; The polyorganosiloxane is preferably a linear polyorganosiloxane represented by the formula (where n is a number that provides a viscosity at 23° C. of 10 mPa·s to 500,000 mPa·s).

[0026] R 6 is preferably an alkyl group or an aryl group.

[0027] From the viewpoint of controlling physical properties such as refractive index, R 6 At least a part of R may be an aryl group such as a phenyl group. 6 In view of ease of availability, polyorganosiloxanes in which all r are methyl are preferred. It is also preferred that r is 2. In other words, component (A) is preferably a linear polyorganosiloxane in which at least one hydrolyzable group exists only at each end of the molecule.

[0028] Therefore, component (A) has R at both ends. a 3-m R 6 m SiO 1 / 2 It is blocked by units, and the intermediate unit is R 6 2SiO 2 / 2 The linear polyorganosiloxane unit (wherein R a is a hydrolyzable group, and R 6 is a monovalent hydrocarbon group having no aliphatic unsaturated bonds, and m is 0, 1 or 2).

[0029] It is particularly preferred that component (A) be one in which p and q in formula (6) are 0 or 1, that is, one having two or more hydrolyzable groups at each of the molecular terminals.

[0030] The viscosity of component (A) is preferably 10 mPa·s to 500,000 mPa·s, and particularly preferably 150 mPa·s to 100,000 mPa·s, at 23° C. When the viscosity of component (A) is within this range, saltwater resistance and uniformity tend to be better.

[0031] Component (A) can be a commercially available product, or a polyorganosiloxane into which a hydrolyzable group has been introduced by a known reaction.

[0032] Component (A) may be one kind of component or a combination of two or more kinds of components.

[0033] [(B) Curing catalyst] Component (B) is a curing catalyst. Component (B) promotes the hydrolytic condensation of component (A), component (C) containing a silicon-bonded hydrolyzable group, and the optional crosslinking agent (D). Examples of component (B) include metal catalysts, organic acid catalysts, inorganic acid catalysts, and base catalysts. The organic acid catalysts, inorganic acid catalysts, and base catalysts do not contain metal atoms.

[0034] Examples of the metal catalyst include metal carboxylates and organometallic compounds. Examples of metals contained in the metal catalyst include titanium, zirconium, tin, aluminum, iron, manganese, and zinc.

[0035] The metal carboxylate is not particularly limited as long as it is a carboxylic acid compound containing the above metal, and preferred examples of the metal carboxylate include iron octoate, manganese octoate, zinc octoate, tin naphthate, tin caprylate, and tin oleate.

[0036] The organometallic compound is not particularly limited as long as it is an organic compound containing the above-mentioned metal, and the organometallic compound is preferably an organotitanium compound, an organozirconium compound, an organotin compound, an organoaluminum compound, or the like.

[0037] Examples of the organic titanium compound include tetraethoxytitanium, tetrapropoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, diisopropoxytitanium bis(ethylacetoacetate), 1,3-propanedioxytitanium bis(ethylacetoacetate), and the like.

[0038] Examples of the organic zirconium compound include zirconium tetraacetylacetonate, tetraisopropoxyzirconium, tetrapropoxyzirconium, tetra-n-butoxyzirconium, tetraisobutoxyzirconium, tributoxyzirconium acetylacetonate, and tributoxyzirconium stearate.

[0039] Examples of organotin compounds include dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diolate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis(triethoxysiloxy)tin, dioctyltin dilaurate, and dimethyltin dineodecanoate.

[0040] Examples of the organoaluminum compound include aluminum trisacetylacetonate, aluminum trisethylacetoacetate, diisopropoxyaluminum ethylacetoacetate, and triethoxyaluminum.

[0041] Examples of the organic acid catalyst include compounds having a carboxylic acid group, a sulfonic acid group, and a phosphoric acid group. Preferred examples of the organic acid catalyst include acetic acid, trifluoroacetic acid, methanesulfonic acid, toluenesulfonic acid, and alkylphosphoric acid.

[0042] Examples of inorganic acid catalysts include hydrochloric acid and sulfuric acid.

[0043] Examples of basic catalysts include amine compounds such as ammonia, triethylamine, and diethylamine; dialkylhydroxylamines such as dimethylhydroxylamine and diethylhydroxylamine; and guanidyl compounds such as tetramethylguanidine, guanidyl group-containing silanes, and guanidyl group-containing siloxanes.

[0044] Component (B) is preferably a metal catalyst. Metal catalysts are easily dissolved or dispersed in the composition, contributing to the promotion of a uniform reaction. Metal catalysts contain little foreign matter, contributing to the formation of a transparent cured product of the composition. Component (B) is particularly preferably an organotitanium compound.

[0045] Component (B) may be one kind of component or a combination of two or more kinds of components.

[0046] [(C) Compounds containing, in one molecule, a mercaptobenzothiazolyl group and at least one member selected from the group consisting of a silicon-bonded hydrolyzable group and a siloxane chain] Component (C) is a compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one selected from the group consisting of a silicon-bonded hydrolyzable group and a siloxane chain. Component (C) may contain both a silicon-bonded hydrolyzable group and a siloxane chain, or it may contain only one of a silicon-bonded hydrolyzable group and a siloxane chain.

[0047] When component (C) contains a silicon-bonded hydrolyzable group, a crosslinking reaction with other components proceeds. This allows the effects of the present invention to be efficiently achieved. Furthermore, when component (C) contains a siloxane chain, the compatibility of component (C) with other components in the composition can be improved. This allows the effects of the present invention to be efficiently achieved even when component (C) does not contain a silicon-bonded hydrolyzable group. Furthermore, when component (C) contains a silicon-bonded hydrolyzable group and a siloxane chain, the effects of the present invention can be more efficiently achieved.

[0048] <Mercaptobenzothiazolyl group> A mercaptobenzothiazolyl group is a monovalent group formed by removing a hydrogen atom from the mercapto group of 2-mercaptobenzothiazole. Specifically, it is a group represented by the following formula (4). [ka]

[0049] <Siloxane chain> The siloxane chain can be linear, branched, cyclic, or a combination thereof. 7 R 8 O 2 / 2 ] units (preferably D units), [SiR 9 O 3 / 2 ] units (preferably T units) and [SiO 4 / 2 ] (Q unit), where R 7 , R 8 and R 9 are each independently a hydrocarbon group. 7 , R 8 and R 9 and R when it is a hydrocarbon group. 1 For example, [SiR 7 R 8 O 2 / 2 ] units, and can take a linear structure consisting of only [SiR 7 O 3 / 2 By including the [SiR] unit, a branched or cyclic structure can be obtained, and by including the Q unit, a three-dimensional network structure can be obtained. 7 R 8 O 2 / 2 ] units, [SiR 9 O 3 / 2 A finite number of combinations of [SiR] units and Q units include at least two bond sites, but the site where the siloxane skeleton is bonded to another group may be located in any part of each unit constituting the siloxane skeleton. 7 R 8 O 2 / 2] units form a cyclic structure, the group R 7 or R 8 can be bonded to other groups. For example, a group having a cyclic siloxane skeleton is [SiR 7 R 8 O 2 / 2 ] at least two groups R of a cyclic siloxane consisting of four units 7 is a bond to a hydrocarbon group such as an ethylene group, the following structure is preferred. [ka] (In the formula, the wavy line portion is the portion that bonds to the silicon atom to which the hydrolyzable group is bonded, the mercaptobenzothiazolyl group, and the optionally present group (for example, the carbon atom of the alkylene group).)

[0050] The siloxane chain is preferably a divalent or higher group because it can function as a spacer (linking group) between a mercaptobenzothiazolyl group and a hydrolyzable silyl group, or as a spacer between two mercaptobenzothiazolyl groups.

[0051] <Hydrolyzable group bonded to silicon atom> The hydrolyzable group bonded to the silicon atom is as described above in component (A).

[0052] <Other groups> Component (C) may contain other groups, such as alkylene groups, which may be interrupted by -S- or linear or cyclic siloxane chains. Other groups include the X groups described below. 1 ~X 3 Examples include:

[0053] Component (C) preferably contains one or two mercaptobenzothiazolyl groups per molecule, and particularly preferably contains one or two mercaptobenzothiazolyl groups, a siloxane chain, and a hydrolyzable group bonded to a silicon atom per molecule.

[0054] Component (C) is preferably a compound represented by general formula (1), (2) or (3).

[0055] <Compound represented by general formula (1)> The compound represented by general formula (1) is as follows: [ka] [In the ceremony, A 1 , X 1 , R 1 is as described above.

[0056] The compound represented by general formula (1) is a compound containing one mercaptobenzothiazolyl group, a hydrolyzable group bonded to a silicon atom, and optionally a siloxane chain in one molecule.

[0057] A 1 is expressed as equation (4): [ka] It is a group represented by the following formula:

[0058] X 1 is an alkylene group which may be interrupted by -S- or a linear or cyclic siloxane chain. 1 The structure represented by the formula 1 (i.e., a mercaptobenzothiazolyl group represented by formula (4)) and a hydrolyzable silyl group (i.e., a group: -SiR 1 3) is a moiety that acts as a spacer for the group represented by X 1 The structure of the alkylene group in X may be linear, branched, cyclic, or a combination thereof, and is preferably linear. 1 The alkylene group preferably has 1 to 20 carbon atoms, and particularly preferably has 1 to 6 carbon atoms.

[0059] R 1are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R 1 R is a hydrolyzable group. Here, the hydrolyzable group is as described in component (A). 1 When R is a hydrocarbon group, it is preferably an alkyl group. 1 is preferably a hydrolyzable group.

[0060] <Compound represented by general formula (2)> The compound represented by general formula (2) is as follows: [ka] [In the ceremony, A 2 , A 3 , X 2 , X 3 , R 2 , R 3 , L 1 is as described above.

[0061] The compound represented by general formula (2) is a compound containing two mercaptobenzothiazolyl groups, a hydrolyzable group bonded to a silicon atom, and optionally a siloxane chain in one molecule. 1 When is 1 or more, the compound represented by general formula (2) is a compound containing two mercaptobenzothiazolyl groups, a siloxane chain, and a hydrolyzable silyl group in one molecule.

[0062] A 2 and A 3 is A 1 X 2 and X 3 is X 1 Also, R 2 is R 1 From the viewpoint of hardening, all R 2 is preferably a hydrolyzable group. 3 is a hydrocarbon group. 1 is synonymous with.

[0063] L 1 is the repeating number of the siloxane chain consisting of D units. 1 is 0 or a number from 1 to 1,000, preferably 0 or a number from 1 to 300, and particularly preferably 0 or a number from 1 to 150.

[0064] <Compound represented by general formula (3)> The compound represented by general formula (3) is as follows: [ka] [In the ceremony, A 4 , X 4 , X 5 , R 4 , R 5 , a, b, and c are as defined above.

[0065] The compound represented by general formula (3) is a compound containing one or more mercaptobenzothiazolyl groups, a hydrolyzable group bonded to a silicon atom, and an alkylene group interrupted by a cyclic siloxane chain in one molecule. That is, the compound represented by general formula (3) is a compound containing X 4 and X 5 form an alkylene group, which is interrupted by cyclic siloxanes bounded by a, b, and c.

[0066] A 4 is A 1 It is synonymous with R. 4 is a hydrocarbon group. 1 Also, R 5 is R 1 From the viewpoint of curability, in general formula (3), all of R 5 is preferably a hydrolyzable group.

[0067] X 4 and X 5 are each independently an alkylene group which may be interrupted by -S- or a linear siloxane chain. 4 and X 5is preferably an uninterrupted alkylene group. 4 and X 5 The alkylene group preferably has 1 to 20 carbon atoms, and particularly preferably has 1 to 6 carbon atoms.

[0068] a is an integer of 1 or more. When a is an integer of 2 or more, each A 4 , X 4 and R 4 are the same or different. From the viewpoint of anticorrosion effect, a is preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2. When a is an integer of 2 or more, each A 4 , X 4 and R 4 are preferably the same.

[0069] b is an integer of 0 or 1 or more. When b is an integer of 2 or more, each X 4 , R 4 and R 5 are the same or different. When b is an integer of 1 or more, the compound represented by general formula (3) contains a hydrolyzable group bonded to a silicon atom. From the viewpoint of curability, b is preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2. When b is an integer of 2 or more, each X 4 , R 4 and R 5 are preferably the same.

[0070] c is an integer of 0 or 1 or more. When c is an integer of 2 or more, each R 4 are the same or different. From the viewpoint of ease of synthesis and handling, c is preferably 0 or an integer of 1 to 3, and particularly preferably 0 or an integer of 1 to 2. When c is an integer of 2 or more, each R 4 are preferably the same.

[0071] Furthermore, a+b+c is an integer of 3 or greater. When a+b+c is an integer of 3 or greater, the main skeleton becomes a cyclic organosiloxane. From the viewpoint of ease of synthesis, a+b+c is preferably an integer of 3 to 8, and particularly preferably an integer of 4 to 6.

[0072] Component (C) is preferably one or more compounds selected from the group consisting of Compounds 1 to 8 in the Examples.

[0073] Component (C) may be one kind of component or a combination of two or more kinds of components.

[0074] <Method for producing component (C)> Component (C) can be obtained by reacting a salt of mercaptobenzothiazole with a silane compound. Specifically, component (C) can be obtained by reacting a salt of mercaptobenzothiazole with a siloxane having a halogenated alkyl group. An example of a synthesis method with a simplified structure is shown below. Furthermore, a compound having a siloxane skeleton as a spacer group can be synthesized by reacting the compound obtained by the method below with polydimethylsiloxane. [ka]

[0075] The ratio of the amount of the mercaptobenzothiazole salt to the amount of the siloxane having a halogenated alkyl group can be set as appropriate, but the amount of the siloxane having a halogenated alkyl group relative to the amount of the mercaptobenzothiazole salt is preferably 0.5 to 1.5 moles, and particularly preferably 0.8 to 1.2 moles.

[0076] In the method for producing component (C), a solvent may be used as needed. The solvent is not particularly limited as long as it is non-reactive with the raw material compounds. Examples of the solvent include aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and cyclohexane; ether solvents such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; halogenated solvents such as chloroform and dichloromethane; amide solvents such as formamide, dimethylformamide, and N-methylpyrrolidone; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

[0077] In the method for producing component (C), the reaction temperature and reaction time can be set appropriately. When a solvent is used, the reaction temperature can be in the range of room temperature (23°C) to the boiling point of the solvent. The reaction time is preferably 1 to 12 hours and can be set appropriately depending on the reaction temperature.

[0078] [Additional Ingredients] The composition may contain additional components within the scope of the present invention. Examples of additional components include (D) a crosslinking agent, (E) an adhesion promoter, (F) a polyorganosiloxane having no hydrolyzable silyl groups, and a component (G) other than components (D) to (F). Components (D) to (F) exclude components corresponding to components (A) to (C).

[0079] <(D) Crosslinking Agent> Component (D) is a crosslinking agent. Examples of component (D) include a compound having at least two silicon-bonded hydrolyzable groups or a partial hydrolysis condensate thereof. Component (D) is a compound that undergoes a crosslinking reaction (condensation reaction) with component (A), specifically, with the silicon-bonded hydrolyzable groups of component (A). Component (D) does not contain any reactive functional groups other than the hydrolyzable groups. Examples of the reactive functional groups include primary amino groups, epoxy groups, (meth)acryloyl groups, (meth)acryloxy groups, mercapto groups, and isocyanato groups.

[0080] Component (D) is R 10 uSi(OR 11 ) 4-u (In the formula, R 10 is independently in each occurrence an unsubstituted or substituted monovalent hydrocarbon group; R 11 is preferably an organosilicon compound represented by the formula (I) or a partial hydrolysis condensate thereof, wherein each occurrence of is independently an unsubstituted or substituted monovalent hydrocarbon group, and u is 0, 1, or 2.

[0081] R 10 is preferably an unsubstituted or halogen-substituted alkyl, cycloalkyl, aryl, aralkyl or alkenyl group.

[0082] R 11 is preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably CH3- or C2H5-.

[0083] Preferably, u is 1 or 2.

[0084] Component (D) is particularly preferably an alkoxy group-containing compound selected from the group consisting of tetramethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, decyltrimethoxysilane, phenyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, and 3-chloropropyltrimethoxysilane; a partial hydrolysis condensate of the alkoxy group-containing compound; or a combination thereof.

[0085] Component (D) may be one kind of component or a combination of two or more kinds of components.

[0086] <(E) Adhesion promoter> Component (E) is an adhesion promoter. Component (E) is a component that improves the adhesion of a cured product of the composition to substrates such as metals, glass, and plastics. Examples of component (E) include compounds having a silicon-bonded hydrolyzable group and a reactive organic functional group, and / or partial hydrolysis condensates of the above compounds (excluding those corresponding to components (A) to (C)). Examples of the reactive organic functional group include a primary amino group, an epoxy group, a (meth)acryloyl group, a (meth)acryloxy group, a mercapto group, and an isocyanato group.

[0087] Specific examples of component (E) include alkoxysilyl group-containing isocyanurate compounds, alkoxysilyl group-containing carbasilatrane compounds, alkoxysilyl group-containing fumaric acid ester compounds, and alkoxysilyl group-containing amine compounds.

[0088] Examples of the alkoxysilyl group-containing isocyanurate compound include tris[(3-trialkoxysilyl)propyl]isocyanurates such as tris[(3-trimethoxysilyl)propyl]isocyanurate and tris[(3-triethoxysilyl)propyl]isocyanurate.

[0089] Examples of alkoxysilyl group-containing fumaric acid ester compounds include bis(3-trimethoxysilylpropyl)fumarate, bis(3-triethoxysilylpropyl)fumarate, etc. Examples of alkoxysilyl group-containing amine compounds include bis(3-trimethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)amine, tris(3-trimethoxysilylpropyl)amine, tris(3-triethoxysilylpropyl)amine, etc.

[0090] Examples of alkoxysilyl group-containing epoxy compounds include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3,4-epoxycyclohexylethyltrimethoxysilane.

[0091] Component (E) may be one kind of component or a combination of two or more kinds of components.

[0092] <(F) Polyorganosiloxane having no hydrolyzable groups bonded to silicon atoms> Component (F) is a polyorganosiloxane that does not have a silicon-bonded hydrolyzable group. When the composition contains component (F), the hardness of the cured product of the composition and / or the viscosity of the composition tend to be controlled. Furthermore, when the composition contains component (F), the handleability of the composition and the required physical properties can be widely accommodated.

[0093] Examples of component (F) include siloxane resins such as polydimethylsiloxane that do not have a curable functional group. Examples of the siloxane resin of component (F) include resins obtained by combining the M unit, D unit, T unit, and / or Q unit and that do not have a hydrolyzable group.

[0094] Component (F) is a compound represented by the following general formula (7): R 6 3Si-O-(SiR 6 2O) v -SiR 6 3(7) (In the formula, R 6 is as defined in general formula (6), v is the number that gives a viscosity of 1 mPa·s to 10,000 mPa·s at 23°C. Preferably, the siloxane resin is represented by the formula:

[0095] The viscosity of component (F) is preferably 1 mPa·s to 10,000 mPa·s, and particularly preferably 1 mPa·s to 1,000 mPa·s, at 23° C. When the viscosity of component (F) is within this range, viscosity adjustment can be carried out more efficiently.

[0096] Component (F) may be one kind of component or a combination of two or more kinds of components.

[0097] <Ingredients (G) other than ingredients (D) to (F)> Examples of the component (G) include inorganic fillers, flame retardants, heat resistance imparting agents, organic solvents, inorganic pigments, and organic pigments. Component (G) may be one kind of component or a combination of two or more kinds of components.

[0098] The composition preferably further contains one or more members selected from the group consisting of (D) a crosslinking agent, (E) an adhesion promoter, and (F) a polyorganosiloxane having no hydrolyzable silyl group.

[0099] <Content of each ingredient> In the composition, the content of each component is preferably as follows.

[0100] The content of component (A) is not particularly limited as long as it is an amount that allows the curable polyorganosiloxane composition to have a handleable viscosity range. The content of component (A) is preferably 50.0 to 99.9 parts by mass, more preferably 70.0 to 98.0 parts by mass, and particularly preferably 80.0 to 95.0 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C).

[0101] The content of component (B) is a catalytic amount relative to the total amount of the curable polyorganosiloxane composition. From the viewpoint of curability, the content of component (B) is preferably 0.01 to 10.0 parts by mass, particularly preferably 0.03 to 5.0 parts by mass, relative to 100 parts by mass of component (A).

[0102] From the viewpoint of corrosion prevention, the content of component (C) is preferably 0.1 to 30.0 parts by mass, more preferably 0.2 to 20.0 parts by mass, and particularly preferably 0.3 to 10.0 parts by mass, per 100 parts by mass of component (A).

[0103] The total content of components (A) to (C) relative to 100 parts by mass of the composition is preferably 50 to 100 parts by mass, more preferably 75 to 100 parts by mass, and particularly preferably 80 to 100 parts by mass.

[0104] From the viewpoints of storage stability and curability, the content of component (D) is preferably 0 to 30.0 parts by mass, more preferably 0.1 to 20.0 parts by mass, and particularly preferably 0.5 to 15.0 parts by mass, per 100 parts by mass of component (A).

[0105] Component (D) can contain, for example, 1 to 30 moles, and specifically 2 to 20 moles, of hydrolyzable groups of component (D) per mole of hydrolyzable groups bonded to silicon atoms of component (A).

[0106] From the viewpoint of exhibiting higher adhesion to the substrate, the content of component (E) is preferably 0 to 20.0 parts by mass, more preferably 0.05 to 20.0 parts by mass, even more preferably 0.1 to 15.0 parts by mass, and particularly preferably 0.5 to 10.0 parts by mass, per 100 parts by mass of component (A).

[0107] From the viewpoint of coating performance, the content of component (F) is preferably 0 to 50 parts by mass, more preferably 0.1 to 50 parts by mass, and particularly preferably 1 to 30 parts by mass, per 100 parts by mass of component (A).

[0108] The content of component (G) is not particularly limited as long as it does not impair the intended use of the curable polyorganosiloxane composition.

[0109] [Method for producing curable polyorganosiloxane composition] The curable polyorganosiloxane composition can be produced by uniformly kneading components (A) to (C) and optional components (D) to (F) using a mixing means such as a universal mixer or kneader.

[0110] [Uses of the curable polyorganosiloxane composition] The curable polyorganosiloxane composition can be used as a metal surface treatment agent. Examples of metals include aluminum, copper, nickel, iron, brass, and stainless steel. The curable polyorganosiloxane composition can also be used as a coating agent for electronic components.

[0111] [Cured product of curable polyorganosiloxane composition] A cured product obtained by curing the curable polyorganosiloxane composition can be obtained by curing the curable polyorganosiloxane composition. For example, the curing conditions (i.e., heating temperature and heating time) for a thickness of the curable polyorganosiloxane composition of about 0.1 mm include conditions of room temperature (20 to 30°C) for several hours (2 to 3 hours). If necessary, curing can be accelerated by heating to a temperature above 30°C and not higher than 60°C. The curing conditions are preferably room temperature and a relative humidity of 40 to 60% RH.

[0112] The cured product obtained by curing the curable polyorganosiloxane composition can be used as a surface coating for metals. The cured product obtained by curing the curable polyorganosiloxane composition can also be used as a coating for electronic components such as electronic devices and integrated circuit elements. Therefore, electronic components containing the curable polyorganosiloxane composition are also within the scope of the present invention.

[0113] [Article containing a cured product of the curable polyorganosiloxane composition] The article comprising the cured product of the curable polyorganosiloxane composition is preferably an article comprising a substrate and a cured product of the composition. Examples of articles comprising a substrate and a cured product of the composition include electronic devices, integrated circuit elements, and other electronic components.

[0114] The method for producing the article is not particularly limited, and preferably includes the steps of preparing a component including a substrate and a composition, applying the composition to a surface of the substrate, and curing the composition to form a cured product of the composition on the substrate.

[0115] In addition to metals, examples of the substrate include epoxy resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate (PBT) resins, engineering plastics such as polycarbonate resins, acrylic resins, polyimide resins, phenolic resins, polyamide resins, polyphenylene sulfide (PPS) resins, and modified polyphenylene ether (PPE) resins; and glass. If necessary, the wall surfaces of the gaps may be treated with a primer in accordance with conventional methods. The shape and thickness of the substrate are not particularly limited.

[0116] Examples of methods for applying the curable polyorganosiloxane composition include dripping, pouring, casting, extrusion from a container, coating such as bar coating or roll coating, screen printing, dipping, brushing, spraying, and dispensing. The composition may be applied uniformly over the entire surface of the part, or unevenly or partially, such as in lines, stripes, or dots. The applied thickness of the composition is preferably 0.01 to 3 mm, and particularly preferably 0.05 to 2 mm.

[0117] The curing conditions for the composition are as described above for the cured product of the composition.

[0118] [(C) A compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one member selected from the group consisting of a silicon-bonded hydrolyzable group and a siloxane chain] Another aspect of the present invention is a compound (C) (hereinafter sometimes referred to as "compound (C)") containing, in one molecule, a mercaptobenzothiazolyl group and one or more selected from the group consisting of a silicon-bonded hydrolyzable group and a siloxane chain. Compound (C), including preferred embodiments, is as described above for component (C). Therefore, compound (C) is preferably a compound containing, in one molecule, one or two mercaptobenzothiazolyl groups, a siloxane chain, and a silicon-bonded hydrolyzable group. Furthermore, compound (C) is particularly preferably a compound represented by general formula (1), (2), or (3).

[0119] Compound (C) can impart excellent saltwater resistance and uniformity to the curable silicone composition. Therefore, compound (C) can be used as an agent for improving saltwater resistance and uniformity for the second curable polyorganosiloxane composition. Here, the second curable polyorganosiloxane composition contains component (A) and component (B), and optionally contains one or more components selected from the group consisting of component (D), component (E), component (F), and component (G). The components and their contents, including preferred embodiments, are as described above for the curable polyorganosiloxane composition. [Example]

[0120] The present invention will be described in more detail below with reference to examples and comparative examples. In these examples, parts are by mass and viscosity is measured at 23° C. The present invention is not limited to these examples.

[0121] <Ingredients used> Component (A): α,ω-bis(trimethoxysiloxy)polydimethylsiloxane (viscosity 300 mPa·s) Component (B): Diisopropoxybis(ethylacetoacetate) titanium Component (C): Compound 1 to Compound 8 Component (D): Methyltrimethoxysilane Component (E): Tris[(3-trimethoxysilyl)propyl]isocyanurate Component (F): Polydimethylsiloxane (viscosity 100 mPa·s)

[0122] Comparative component (C'): 2-Heptadecylimidazole 1,2,4-triazole 2-Mercaptobenzothiazole 1,2,3-benzotriazole

[0123] (Production of Component (C) (Compounds 1 to 8)) <Compound 1> A 3,000 ml flask equipped with a nitrogen gas inlet tube and a condenser was charged with 1,200 g of xylene and 200 g (1.06 mol) of 2-mercaptobenzothiazole sodium (Tokyo Chemical Industry Co., Ltd.), followed by 231 g (1.16 mol) of 3-chloropropyltrimethoxysilane, and the mixture was stirred under a nitrogen stream at 120°C for 20 hours. After cooling, the unreacted sodium salt was filtered off, and then the xylene was distilled off at 135°C to obtain 301 g of compound 1. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0124] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.5 ppm, -CH2-C H 2-Si: 0.5 to 1 ppm, -CH2-C H 2-CH2-Si: 1.6 to 1.9 ppm, -SC H 2-: 3.3 to 3.4 ppm

[0125] [ka]

[0126] <Compound 2> A 3,000 ml flask equipped with a nitrogen gas inlet tube and a condenser was charged with 1,200 g of xylene and 200 g (1.06 mol) of 2-mercaptobenzothiazole sodium (Tokyo Chemical Industry Co., Ltd.), followed by 88.0 g (1.15 mol) of allyl chloride. The mixture was stirred at 120°C for 20 hours under a nitrogen stream. After cooling, the sodium salt was filtered, and the xylene and excess allyl chloride were distilled off at 135°C. Next, 1,000 g of xylene, 206 g (1.05 mol) of 3-mercaptopropyltrimethoxysilane, and 0.5 g of AIBN (azobisisobutyronitrile) were added. The mixture was heated and stirred at 60°C for 7 hours, after which the xylene and unreacted 3-mercaptopropyltrimethoxysilane were distilled off, yielding 331 g of Compound 2. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0127] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.5 ppm, -SC H 2CH2C H 2Si-(OCH3)3, -SC H 2CH2C H 2-S-: 0.5 ppm to 1.0 ppm, -S-CH2 CH 2CH2-S-, -S-CH2 CH 2CH2Si(OCH3)3-: 1.8ppm~2ppm

[0128] [ka]

[0129] <Compound 3> A 5,000 ml flask equipped with a nitrogen gas inlet tube and a condenser was charged with 600 g (2.59 mol) of 1,3-bis(chloromethyl)-tetramethyldisiloxane, 348.5 g (2.59 mol) of 1,1,3,3-tetramethyldisiloxane, and 4.7 g of trifluoromethanesulfonic acid, and stirred under a nitrogen stream for 6 hours. The mixture was diluted with 770 g of toluene, washed with water, dehydrated, and distilled to yield 279 g of a 41 wt% toluene solution of 1-chloromethyl-1,1,3,3-tetramethyldisiloxane.

[0130] A 500 ml flask equipped with a nitrogen gas inlet tube and condenser was charged with 70 g of toluene, 51.7 g (0.35 mol) of vinyltrimethoxysilane, and 1.54 g of alumina-supported platinum catalyst, and heated to 120°C under a nitrogen stream. 135 g (0.30 mol) of a 41 wt% toluene solution of 1-chloromethyl-1,1,3,3-tetramethyldisiloxane was added dropwise over approximately 1 hour. The reaction was then allowed to proceed at 120°C for 2 hours, yielding a reaction solution. The resulting reaction solution was cooled to room temperature (25°C) and filtered. The excess vinyltrimethoxysilane and toluene were removed by distillation under reduced pressure, yielding 149.1 g of a toluene solution of the 1-chloromethyl-1,1,3,3-tetramethyldisiloxane-vinyltrimethoxysilane reaction product.

[0131] A 2,000 ml flask equipped with a nitrogen gas inlet and condenser was charged with 77.3 g (0.41 mol) of 2-mercaptobenzothiazole sodium (Tokyo Chemical Industry Co., Ltd.), 400 g of xylene, and 4.2 g of amine catalyst. The mixture was heated to 120 °C under a nitrogen stream. 149.1 g of a toluene solution of the 1-chloromethyl-1,1,3,3-tetramethyldisiloxane-vinyltrimethoxysilane reaction product was added dropwise, and the reaction was carried out at 125 °C for 3 hours. The resulting reaction solution was then filtered and thermally stripped under reduced pressure to remove the xylene and toluene, yielding 131.1 g of the desired compound 4. The yield for this reaction was 98%. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0132] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.5 ppm, Si-CH2-CH2-Si: 0.5 to 1 ppm, -S-CH2-Si: 2.5 ppm, CH3-Si-CH3: -0.2 ppm to 0.2 ppm

[0133] [ka]

[0134] <Compound 4> To 1 mol of compound 3, 2.5 mol of 1,1,3,3,5,5,7,7-octamethylcyclotetrasiloxane was added, and the mixture was subjected to a ring-opening equilibration reaction using an acid catalyst, followed by neutralization to prepare the compound. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0135] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.5 ppm, Si-CH2-CH2-Si: 0.5 to 1 ppm, -S-CH2-Si: 2.5 ppm, CH3-Si-CH3: -0.1 ppm to 0.2 ppm

[0136] [ka]

[0137] <Compound 5> A 1,000 ml flask equipped with a nitrogen gas inlet tube and condenser was charged with 100 g (0.22 mol) of polysiloxane silanol oligomer, HO(CH3)2Si-[O-Si(CH3)2]4-O-Si(CH3)2OH, 429.3 g (2.2 mol) of trimethoxysilylpropyl chloride, and 3 g of condensation catalyst. The mixture was heated under a nitrogen stream at 80°C for 18 hours and 120°C for 2 hours. Excess trimethoxysilylpropyl chloride was removed by thermal stripping under reduced pressure. 168.1 g of ClCH2CH2CH2(OCH3)2Si-[O-Si(CH3)2]6-O-Si(OCH3)2CH2CH2CH2Cl was obtained.

[0138] A 500 ml flask equipped with a nitrogen gas inlet and condenser was charged with 34 g (0.18 mol) of 2-mercaptobenzothiazole sodium (Tokyo Chemical Industry Co., Ltd.), 180 g of xylene, 55 g (0.07 mol) of ClCH2CH2CH2(OCH3)2Si-[O-Si(CH3)2]6-O-Si(OCH3)2CH2CH2CH2Cl, and 1.8 g of amine catalyst. The mixture was reacted at 130-140°C for 10 hours. After filtration and heat stripping under reduced pressure to remove the xylene, 72.6 g of the target compound 5 was obtained. The yield of this reaction was 99%. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0139] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.4 ppm to 3.5 ppm, CH3-Si-CH3: -0.2 ppm to 0.2 ppm, -S-CH2CH2 CH 2(OCH3)2Si-, -Si(OCH3)2 CH 2CH2CH2-S-: 0.6 ppm to 0.8 ppm, -S-CH2 CH 2CH2(OCH3)2Si-, -Si(OCH3)2CH2 CH 2CH2-S-: 1.8 ppm to 2 ppm, -S- CH2CH2CH2(OCH3)2Si-, -Si(OCH3)2CH2CH2 CH 2-S-: 3.2 ppm to 3.3 ppm

[0140] [ka]

[0141] <Compound 6> A 2,000 ml flask equipped with a nitrogen gas inlet tube and a condenser was charged with 800 g of xylene, 157 g (0.83 mol) of 2-mercaptobenzothiazole sodium (Tokyo Chemical Industry Co., Ltd.), and 80 g (0.35 mol) of 1,3-bis(chloromethyl)tetramethyldisiloxane, and heated at 125°C for 3 hours under a nitrogen stream. After treatment with activated carbon and washing with water, the mixture was filtered and dehydrated at 140°C, and the xylene and excess materials were distilled off at 140°C to yield 126 g of the intermediate compound: 1,3-bis[(2-mercaptobenzothiazole)methyl]tetramethyldisiloxane.

[0142] Next, 40 g (0.81 mol) of 1,3-bis[(2-mercaptobenzothiazole)methyl]tetramethyldisiloxane and 45 g (0.152 mol) of 1,1,3,3,5,5,7,7-octamethylcyclotetrasiloxane were added to a 300 ml flask equipped with a nitrogen gas inlet tube and a condenser. 4 g of an acid catalyst was then added, followed by heating and stirring at 130°C for 4 hours. After cooling, the mixture was diluted with 600 g of xylene and neutralized by washing several times with ion-exchanged water. The xylene and other components were then distilled off at 140°C under a nitrogen atmosphere, and the mixture was then distilled under reduced pressure at 80°C to obtain 67 g of compound 6. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0143] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.4 ppm to 3.5 ppm, CH3-Si-CH3: -0.2 ppm to 0.3 ppm

[0144] [ka]

[0145] <Compound 7> To 1 mol of compound 5, 1 mol of 1,1,3,3,5,5,7,7-octamethylcyclotetrasiloxane was added, and a ring-opening equilibration reaction was carried out in the presence of an acid catalyst, followed by neutralization to prepare the compound. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0146] [ka]

[0147] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.4 ppm to 3.5 ppm, CH3-Si-CH3: -0.2 ppm to 0.3 ppm, -S-CH2CH2C H 2(OCH3)2Si-, -Si(OCH3)2C H 2CH2CH2-S-: 0.6 ppm to 0.8 ppm, -S-CH2C H 2CH2(OCH3)2Si-, -Si(OCH3)2CH2C H 2CH2-S-: 1.8 ppm to 2 ppm, -SC H 2CH2CH2(OCH3)2Si-, -Si(OCH3)2CH2CH2C H 2-S-: 3.2 ppm to 3.3 ppm

[0148] <Compound 8> A 2,000 ml flask equipped with a nitrogen gas inlet tube and a condenser was charged with 800 g of xylene, 53.6 g (0.2 mol) of 1,1,3,3,5,7-hexamethylcyclotetrasiloxane, 18.4 g (0.24 mol) of allyl chloride, and a platinum catalyst (100 ppm platinum equivalent). The mixture was heated and stirred at 80°C for 4 hours. The xylene and excess allyl chloride were then distilled off. Next, 800 g of xylene was added, followed by 34 g (0.18 mol) of 2-mercaptobenzothiazole sodium salt. The mixture was heated at 125°C for 3 hours under a nitrogen stream. The mixture was then treated with activated carbon, filtered, and the xylene was distilled off, yielding 88.7 g of compound 8. 1 Analysis by H-NMR revealed the following results, confirming that this was the target compound.

[0149] [ka]

[0150] C6H4: 7.1 ppm to 7.8 ppm, -Si(OCH3): 3.4 ppm to 3.5 ppm, -Si-CH3:-0.2ppm~0.3ppm, -S-CH2CH2CH2-Si-, -Si-CH2CH2CH2-S-:0.6ppm~0.8ppm, -S-CH2CH2CH2(OCH3)2Si-, -Si-CH2CH2CH2-S-:1.8ppm~2ppm, -S-CH2CH2CH2Si-, -SiCH2CH2CH2-S-:3.2ppm~3.3ppm, -Si-CH2-CH2-Si(OCH3)3:0.5~1ppm

[0151] (Preparation of Curable Silicone Composition) Curable polyorganosiloxane compositions were prepared by mixing the components according to the compositions shown in Tables 1 to 3.

[0152] (Evaluation method) <Appearance> The appearance (uniformity and coloration) of the polyorganosiloxane compositions was measured after preparation, storage at room temperature (23°C) for 7 days, or storage at 5°C for 3 days. The appearance was evaluated by visually inspecting the composition. The uniformity of the composition was evaluated on the following four-point scale. The higher the value, the higher the evaluation of the uniformity of the composition. The coloration of the composition was also evaluated on the following two-point scale. The lower the value, the less the evaluation of the coloration of the composition. Uniformity criteria 4: Transparent 3: Transparent ~ Translucent 2: Translucent 1: Not dissolved or precipitated Coloring criteria 2:Pale yellow 1: Slight yellow

[0153] <Viscosity> The viscosity of the polyorganosiloxane composition at 23°C was measured using a VISCOMETER TVB-10M manufactured by Toki Sangyo Co., Ltd. The rotor used was TM2, and the viscosity was measured under conditions of 60 pm and 1 minute value.

[0154] <Tuck-free time> The polyorganosiloxane composition was applied to a thickness of 100 μm on the surface of a 5 cm diameter aluminum petri dish whose surface had been cleaned with an organic solvent. The time required to confirm that the composition was dry was measured by touching the surface with a finger under an environment of 23°C and 50% relative humidity (RH).

[0155] <Heat resistance> Heat resistance was evaluated by placing copper foil coated with the polyorganosiloxane composition in an atmosphere at 150°C for 30 minutes or in an atmosphere at 85°C and 85% RH for 24 hours. The evaluation was performed by visually judging the change in color tone of the coating film and was rated on the following five-point scale. The higher the value, the higher the heat resistance. 5: Almost no change 4: Slight discoloration 3: Yellowing 2: Orange 1: Dark brown

[0156] <Heat cycle test (reliability)> The copper foil coated with the polyorganosiloxane composition was placed in an atmosphere where the temperature changed from -40 to 125°C over the course of one hour, and this cycle was repeated 250 times. One cycle consisted of changing from -40°C to 125°C in 30 minutes, and then changing from 125°C to -40°C in 30 minutes. Evaluation was performed by visually determining whether cracks occurred in the coating film, and was rated on the following five-point scale. The higher the value, the better the evaluation of reliability. 5: No change 4: Some fine cracks 3: Fine cracks present 2: Cracked 1: Large crack

[0157] <Saltwater resistance> The polyorganosiloxane composition was applied to a copper plate (JIS.H.3100:C1100P) whose surface had been polished with 4000 mesh abrasive paper to a thickness of 100 μm and then cleaned, and then left for 3 days at 23°C and 50% RH to obtain a sample. The obtained sample was immersed in a 5 wt% aqueous sodium chloride solution (salt water), and after 7 days at 50°C, the percentage (%) of the corroded area of ​​the substrate and the location of corrosion were measured. The smaller the value, the higher the saltwater resistance. Furthermore, if the location of corrosion was other than the edge of the substrate, it was determined that the saltwater resistance was poor from the viewpoint of the corrosion resistance of the cured composition.

[0158] <Saltwater resistance> The polyorganosiloxane composition was applied to a JIS2 type substrate (manufactured by Kusumoto Chemicals Co., Ltd., product name: ETAC:JIS2 type) to a thickness of 100 μm, and left in an atmosphere of 23°C and 50% RH for 3 days to obtain a sample. The obtained sample was immersed in a 5 wt% aqueous sodium chloride solution (salt water) and left at 50°C for 7 days, and then dried at room temperature (23°C) for a further 7 days, after which the condition of the substrate was checked. Evaluation was performed by visually judging the change in color tone of the coating film, and was rated on the following 5-point scale. The higher the value, the higher the evaluation of saltwater resistance. 5: No change 4-5: Almost no change 4: There was some discoloration 3: There was discoloration 2-3: Discoloration and disconnection 2: There was a break in the wire 1-2: There was verdigris and a broken wire (the copper part was corroded). 1: There was verdigris

[0159] The results are summarized in Tables 1 to 3.

[0160] [Table 1]

[0161] [Table 2]

[0162] [Table 3]

[0163] As can be seen from Tables 1 and 2, the compositions of the examples were excellent in salt water resistance and uniformity. In particular, comparison of Examples 2-3 with Examples 4-5 shows that saltwater resistance was superior when component (C) was a compound containing a mercaptobenzothiazolyl group, a siloxane chain, and a hydrolyzable group bonded to a silicon atom in one molecule. Furthermore, as shown in Example 9, saltwater resistance was also superior when component (C) was a compound containing a mercaptobenzothiazolyl group and a siloxane chain in one molecule.

[0164] Comparative Example 1 does not contain a component corresponding to compound (C). Comparative Examples 2 to 8 contain, as a component corresponding to compound (C), benzotriazole, imidazole, or the like, which is used as a conventional rust inhibitor. Comparative Example 9 does not use a composition. The compositions of Comparative Examples 2 to 6 were poor in uniformity and saltwater resistance. In particular, the composition of Comparative Example 3 exhibited precipitation of 1,2,4-triazole, and the uniformity of the composition was significantly poor. Furthermore, the compositions of Comparative Examples 1 and 7 to 8 were poor in saltwater resistance. Furthermore, the result of saltwater resistance in Comparative Example 9, which did not use a composition, showed significant corrosion.

Claims

1. (A) a polyorganosiloxane having two or more hydrolyzable groups bonded to silicon atoms in each molecule; (B) a curing catalyst, and (C) A compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one selected from the group consisting of a hydrolyzable group bonded to a silicon atom and a siloxane chain.

1. A curable polyorganosiloxane composition comprising:

2. 2. The curable polyorganosiloxane composition according to claim 1, wherein component (C) is a compound containing one or two mercaptobenzothiazolyl groups, a siloxane chain, and a hydrolyzable group bonded to a silicon atom in one molecule.

3. Component (C) is a compound represented by the following general formula (1), (2), or (3): 【Chemistry 20】 [During the ceremony, A １ is expressed by the formula (4): 【Chemistry 21】 is a group represented by X １ is an alkylene group which may be interrupted by —S— or a linear or cyclic siloxane chain, R １ are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R １ is a hydrolyzable group. 【Chemistry 22】 [During the ceremony, A ２ and A ３ is a group represented by formula (4), X ２ and X ３ are each independently an alkylene group which may be interrupted by —S— or a linear or cyclic siloxane chain; R ２ are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R ２ is a hydrolyzable group, R ３ are each independently a hydrocarbon group, L １ is 0 or a number from 1 to 1,000. 【Chemistry 23】 [During the ceremony, A ４ is a group represented by formula (4), X ４ and X ５ are each independently an alkylene group which may be interrupted by —S— or a linear siloxane chain; R ４ are each independently a hydrocarbon group, R ５ are each independently a hydrolyzable group or a hydrocarbon group, provided that at least one R ５ is a hydrolyzable group, a is an integer of 1 or more, and when a is an integer of 2 or more, each A ４ , X ４ and R ４ are the same or different, b is an integer of 0 or 1 or more, and when b is an integer of 2 or more, each X ４ , R ４ and R ５ are the same or different, c is 0 or an integer of 1 or more, and when c is an integer of 2 or more, each R ４ are the same or different, The curable polyorganosiloxane composition according to claim 1, wherein a + b + c is an integer of 3 or more.

4. 2. The curable polyorganosiloxane composition according to claim 1, further comprising one or more selected from the group consisting of (D) a crosslinking agent, (E) an adhesion promoter, and (F) a polyorganosiloxane having no hydrolyzable groups bonded to silicon atoms.

5. A coating agent for electronic components using the curable polyorganosiloxane composition according to any one of claims 1 to 4.

6. A metal surface treatment agent using the curable polyorganosiloxane composition according to any one of claims 1 to 4.

7. A cured product obtained by curing the curable polyorganosiloxane composition according to any one of claims 1 to 4.

8. An electronic component comprising the curable polyorganosiloxane composition according to any one of claims 1 to 4.

9. (C) A compound containing, in one molecule, a mercaptobenzothiazolyl group and at least one member selected from the group consisting of a hydrolyzable group bonded to a silicon atom and a siloxane chain.

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