WO2014002919A1

WO2014002919A1 - Coating agent, electrical-electronic equipment, and method for protecting metal parts of electrical-electronic equipment

Info

Publication number: WO2014002919A1
Application number: PCT/JP2013/067164
Authority: WO
Inventors: Yoshitsugu Morita; Masaaki Amako; Michitaka Suto; Katsuya Baba
Original assignee: Dow Corning Toray Co Ltd
Current assignee: DuPont Toray Specialty Materials KK
Priority date: 2012-06-28
Filing date: 2013-06-18
Publication date: 2014-01-03
Anticipated expiration: 2014-12-28
Also published as: KR102145008B1; JP6022236B2; TW201412893A; JP2014009272A; KR20150023496A

Description

DESCRIPTION

COATING AGENT, ELECTRICAL-ELECTRONIC EQUIPMENT, AND

METHOD FOR PROTECTING METAL PARTS OF ELECTRICAL- ELECTRONIC EQUIPMENT

Technical Field

[0001] The present invention relates to a coating agent, an electrical-electronic equipment where metal parts are protected by a cured product of the coating agent, and a method for protecting a metal part of an electrical-electronic equipment by the coating agent.

[0002] Priority is claimed on Japanese Patent Application No. 2012-146163, filed on June 28, 2012, the content of which is incorporated herein by reference.

Background Art

[0003] Coating agents composed of curable_silicone ompositions have-been-used-for- protecting electrical-electronic equipments from moisture and dirt. However, if metal parts such as the electrodes of electrical-electronic equipment, electrical circuits on the circuit board, and the like are made of a substance that readily corrodes due to a corrosive substance, there has been a problem in that such metal parts become corroded due to corrosive substances present in the surrounding environment.

[0004] Thus the blending of an inorganic ion exchanger has been proposed in Japanese Unexamined Patent Application Publication No. 2005-120155, although such blending results in problems such as lack of durability, transparency, and the like. Moreover, although, in Japanese Unexamined Patent Application Publication No. 2004-14961 1, a coating agent composed of a room temperature-curable silicone rubber composition is proposed, such a coating agent had the problem of an inability to sufficiently suppress corrosion of metal parts.

[0005] The object of the present invention is to provide a coating agent for suppression of corrosion of metal parts of electrical-electronic equipment by corrosive substances, to provide an electrical-electronic equipment in which corrosion of metal parts by corrosive substances is suppressed, and to provide a method for suppressing corrosion of metal parts of an electrical-electronic equipment by corrosive substances. Disclosure of Invention

[0006] The coating agent of the present invention comprises an organopolysiloxane having a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group.

[0007] The electrical-electronic equipment of the present invention is covered by a cured product of the coating agent.

[0008] The method for protecting a metal part of an electrical-electronic equipment of the present invention comprises the steps of: applying the coating agent to a metal part of an electrical-electronic equipment to be subjected to exposure to a corrosive substance; and curing the coating agent.

Effects of Invention

[0009] The coating agent of the present invention can suppress corrosion of metal parts of electrical-electronic equipment by a corrosive substance. Moreover, the

electrical-electronic _e.q.uiprnent-o.f-the-present-i-n-vent-i-on is characterized n that-corrosion^{^}of^~ the metal part by the corrosive substance is suppressed. Furthermore, the method for protection of the present invention can suppress corrosion of metal parts of electrical- electronic equipment by a corrosive substance.

Brief Description of the Drawings

[0010] Figure 1 A is a photograph showing the appearance of a copper plate prior to a corrosion test.

[0011] Figure IB is a photograph showing the appearance of a copper plate covered by a coating agent prepared according to Comparative Example 1.

[0012] Figure 1C is a photograph showing the appearance of a copper plate covered by a coating agent prepared according to Practical Example 3.

[0013] Figure 2A is a photograph showing the appearance of a copper plate after a corrosion test.

[0014] Figure 2B is a photograph showing the appearance of a copper plate covered by a coating agent prepared according to Comparative Example 1.

[0015] Figure 2C is a photograph showing the appearance of a copper plate covered by a coating agent prepared according to Practical Example 3.

[0016] Figure 3 is a photograph showing change over time of appearance of the LED produced in Practical Example 1 during the corrosion test. [0017] Figure 4 is a photograph showing change over time of appearance of the LED produced in Practical Example 2 during the corrosion test.

[0018] Figure 5 is a photograph showing change over time of appearance of the LED produced in Practical Example 3 during the corrosion test.

[0019] Figure 6 is a photograph showing change over time of appearance of the LED produced in Comparative Example 1 during the corrosion test.

Detailed Description of the Invention

[0020] The coating agent of the present invention will be explained in detail.

[0021] The coating agent of the present invention is composed of a curable silicone composition comprising an organopolysiloxane having a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. No particular limitation is placed on the molecular structure of this organopolysiloxane as long as the organopolysiloxane has a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group.— Examples of this condensed polycyclic aromatic group include a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and such condensed polyaromatic groups where a hydrogen atom is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The condensed polycyclic aromatic group is preferably the naphthyl group. Moreover, examples of the group including a condensed polycyclic aromatic group include alkyl groups including a condensed polycyclic aromatic group such as a naphthyl ethyl group, a naphthyl propyl group, an anthracenyl ethyl group, a phenanthryl ethyl group, a pyrenyl ethyl group, and the like; and such groups where a hydrogen atom in the condensed polycyclic aromatic group is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The alkyl group including a condensed polycyclic aromatic group is particularly preferably the naphthyl ethyl group. In particular, an

organopolysiloxane having an alkyl group including a condensed polycyclic aromatic group has relatively low viscosity and is characterized as being able to lower viscosity of the present coating agent.

[0022] The other group bonding to the silicon atoms in this organopolysiloxane is exemplified by alkyl groups, alkenyl groups, phenyl groups, a hydrogen atom, hydroxyl groups, and alkoxy groups. Examples of this alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group; and the alkyl group is preferably the methyl group. Examples of this alkenyl group include a vinyl group, an allyl group, and a butenyl group; and the alkenyl group is preferably the vinyl group. Examples of this alkoxy group include a methoxy group, an ethoxy group, and a propoxy group.

[0023] As this type of organopolysiloxane, the organopolysiloxane represented by the following average unit formula is preferable.

(R^,3SiO,_/2)a(R^,2Si0₂/2)b( ²Si03/2)c(Si04/2)d

[0024] In the formula, R¹ are alkyl groups, alkenyl groups, phenyl groups or hydrogen atoms. Examples of the alkyl group for R¹ include a methyl group, an ethyl group, a propyl group, and a butyl group. Of these, a methyl group is preferable. Examples of the alkenyl group for R¹ include a vinyl group, an allyl group, and a butenyl group. Of these, a vinyl group is preferable.

[0025] In the formula, R is an alkyl group, an alkenyl group, a phenyl group, a hydrogen atom, or is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Examples of the alkyl group for R² include the groups represented by R¹. Examples of the alkenyl group for R² include the groups represented by R¹. Examples of the condensed polycyclic aromatic group for R² include a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and such condensed polycyclic aromatic groups where a hydrogen atom is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The condensed polycyclic aromatic group for R² is preferably the naphthyl group. Examples of the group including a condensed polycyclic aromatic group for R² include alkyl groups including a condensed polycyclic aromatic group such as a naphthyl ethyl group, a naphthyl propyl group, an anthracenyl ethyl group, a phenanthryl ethyl group, a pyrenyl ethyl group, and the like; and such groups where a hydrogen atom in the condensed polycyclic aromatic group is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The group including a condensed polycyclic aromatic group for R² is particularly preferably the naphthyl ethyl group. An organopolysiloxane where R is an alkyl group including a condensed polycyclic aromatic group has relatively low viscosity, and this organopolysiloxane is characterized as being able to lower viscosity of the present coating agent.

[0026] Further, in the formula, at least one R¹ or R² in a molecule is an alkenyl group or hydrogen atom. Moreover, in the formula, at least one R² in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Preferably, at least 50 mol% of R² in a molecule are condensed polycyclic aromatic groups or a group including a condensed polycyclic aromatic group.

[0027] Further, in the formula, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d <0.2, and a + b + c + d = 1.

Preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.05 < a < 0.7, 0 < b < 0.4, 0.3 < c < 0.9, 0 < d<0.2, and a + b + c + d - 1. Particularly preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.1 < a < 0.6, 0 < b < 0.3,

0.4 < c < 0.9, 0 < d <0.2, and a + b + c + d = l . When the value of "a" is below the lower limit of the range described above, the obtained organopolysiloxane changes from the liquid state to solid state, and handling and processability of the present coating agent declines. On the other hand, transparency of the cured product declines if "a" exceeds the upper limit of the range described above. Further, stickiness of the cured product occurs when "b" exceeds the upper limit of the range described above. Further, refractive index of the cured product may markedly decline if "c" is less than the lower limit of the range described above. On the other hand, the cured product becomes excessively rigid and brittle if "c" exceeds the upper limit of the range described above. Further, the cured product becomes extremely rigid and brittle if "d" exceeds the upper limit of the range described above.

[0028] Although this organopolysiloxane is represented by the above average unit formula, a small amount of the hydroxyl groups or methoxy groups, ethoxy groups, or the like alkoxy groups may be bonded to silicon atoms in the molecule. An

organopolysiloxane having silicon-bonded hydroxyl groups or silicon-bonded alkoxy groups may result in improved adhesivity of the present coating agent, may result in improved adhesion of the cured product of the coating agent to the substrate, or may result in improvement of compatibility with other components included in the coating agent.

[0029] The method of preparation of this type of organopolysiloxane is exemplified by a method, in the presence of an acid or base, of hydrolysis and condensation reaction of a silane compound (I) represented by the general formula: R³SiX₃

a disiloxane (II) represented by the general formula:

R⁴ ₃SiOSiR⁴ ₃

and/or a silane compound (III) represented by the general formula:

R⁴ ₃SiX

[0030] The silane compound (I) represented by the general formula:

R³SiX₃

is a raw material for introducing a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group to the obtained organopolysiloxane. In the formula, R³ is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Examples of the condensed polycyclic aromatic group for R³ include a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and such condensed polycyclic aromatic groups where a hydrogen atom is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. Of these, the naphthyl group is preferable.

Examples of the group including a condensed polycyclic aromatic group for R³ include alkyl groups including a condensed polycyclic aromatic group such as a naphthyl ethyl group, a naphthyl propyl group, an anthracenyl ethyl group, a phenanthryl ethyl group, a pyrenyl ethyl group, and the like; and such groups where a hydrogen atom in the condensed polycyclic aromatic group is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The group including a condensed polycyclic aromatic group for R³ is particularly preferably the naphthyl ethyl group. Further, in the formula, X is an alkoxy group, an acyloxy group, a halogen atom, or a hydroxyl group. Examples of the alkoxy group for X include a methoxy group, an ethoxy group, and a propoxy group. Examples of the acyloxy group for X include an acetoxy group. Examples of the halogen atom for X include a chlorine atom, and a bromine atom.

[0031] This type of silane compound (I) is exemplified by naphthyltrimethoxysilane, anthracenyl trimethoxysilane, phenanthryl trimethoxysilane, pyrenyl trimethoxysilane, naphthyltriethoxysilane, anthracenyl triethoxysilane, phenanthryl triethoxysilane, pyrenyl triethoxysilane, naphthyl ethyl trimethoxysilane, naphthyl propyl trimethoxysilane, anthracenyl ethyl trimethoxysilane, or similar alkoxysilanes; naphthyl triacetoxysilane, anthracenyl triacetoxysilane, phenanthryl triacetoxysilane, pyrenyl triacetoxysilane, or similar acyloxysilanes; naphthyl trichlorosilane, anthracenyl trichlorosilane, phenanthryl trichlorosilane, pyrenyl trichlorosilane, or similar halosilanes; and naphthyl trihydroxy silane, anthracenyl trihydroxy silane, phenanthryl trihydroxy silane, pyrenyl trihydroxy silane, or similar hydroxy silanes.

[0032] The disiloxane (II) represented by the general formula:

R⁴ ₃SiOSiR⁴ ₃

is a raw material for introducing M units of siloxane into the obtained organopolysiloxane. In the formula, R⁴ are alkyl groups, alkenyl groups, or phenyl groups. Examples of the alkyl group for R⁴ include a methyl group, an ethyl group, and a propyl group. Of these, a methyl group is preferable. Examples of the alkenyl group for R⁴ include a vinyl group, an allyl group, and a butenyl group. Of these, a vinyl group is preferable.

[0033] This type of disiloxane (II) is exemplified by l j-divinvl-tetramethvldisiloxane, l ,3-divinyl-l ,3-diphenyl-dimethyldisiloxane, l-vinyl-pentamethyldisiloxane, l-vinyl-1 ,3- diphenyl-trimethyldisiloxane, and 1 ,3-diphenyl-tetramethyldisiloxane,

hexamethyldisiloxane; and this disiloxane (II) is preferably a disiloxane having an alkenyl group.

[0034] The silane compound (III) represented by the general formula:

R⁴ ₃SiX

is a raw material used for introduction of M units of siloxane in the obtained

organopolysiloxane. In the formula, R⁴ is synonymous with the groups described above. In the formula, X is synonymous with the groups described above.

[0035] This type of silane compound (III) is exemplified by

dimethylvinylmethoxysilane, methylphenylvinylmethoxysilane,

diphenylvinylmethoxysilane, dimethylvinylethoxysilane, methylphenylvinylethoxysilane, diphenylvinylethoxysilane, trimethylmethoxysilane, dimethylphenylmethoxysilane, or similar alkoxysilanes; dimethylvinylacetoxysilane, methylphenylvinylacetoxysilane, diphenylvinylacetoxysilane, trimethylacetoxysilane, dimethylphenylacetoxysilane, or similar acyloxysilanes; dimethylvinyl chlorosilane, methylphenylvinyl chlorosilane, diphenylvinyl chlorosilane, trimethyl chlorosilane, methylphenyl chlorosilane, or similar halosilanes; and dimethylvinylsilanol, methylphenylvinylsilanol, diphenylvinylsilanol, or similar silanols; and this silane compound (III) is preferably a silane compound having an alkenyl group.

[0036] As may be required, a silane compound (IV) represented by the general formula:

R⁴(_4-n)SiX_n

may be used as a reactant in the above described preparation method. In the formula, R⁴ is synonymous with the groups described above. In the formula, X is synonymous with the groups described above. In the formula, "n" are integers from 2 to 4.

[0037] This type of silane compound (IV) is exemplified by trimethylmethoxysilane, trimethylethoxysilane, methyldiphenylmethoxysilane, methyldiphenylethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, or similar alkoxysilanes; trimethylacetoxysilane, methyldiphenylacetoxysilane,

dimethyldiacetoxysilane, methylphenyldiacetoxysilane, diphenyldiacetoxysilane, methyltriacetoxysilane, phenyltriacetoxysilane, tetraacetoxysilane, or similar

acetoxysilanes; trimethylchlorosilane, methyldiphenylchlorosilane, dimethyldichlorosilane, methylphenyldichlorosilane, diphenyldichlorosilane, methyltrichlorosilane,

phenyltrichlorosilane, tetrachlorosilane, or similar halosilanes; and trimethylsilanol, methyldiphenylsilanol, dimethyldihydroxysilane, methylphenyldihydroxysilane, diphenyldihydroxysilane, methyltrihydroxysilane, phenyltrihydroxysilane, or similar hydroxysilanes.

[0038] Further, in the preparation method, at least one of components (II) to (IV) used in the reaction of the preparation method must have an alkenyl group.

[0039] The preparation method is characterized as performing hydrolysis and condensation reaction of the silane compound (I), the disiloxane (II) and/or the silane compound (III), and as may be required, the silane compound (IV), in the presence of an acid or a base. The charged ratio of each of the components is the ratio such that the obtained organopolysiloxane has the average unit formula below:

(R⁴ ₃Si0_1/2)_a (R⁴ ₂Si0_2/2)_b (R⁵Si0_3/2)_c (Si0_4/2)_d

[0040] That is to say, in the formula, R⁴ is synonymous with the groups described above. R⁵ is a group represented by R³ or is a group represented by R⁴. However, at least one R⁴ or R⁵ in a molecule is an alkenyl group. At least one R⁵ in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Further, in the formula, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d <0.2, and

a + b + c + d = l . Preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.05 < a < 0.7, 0 < b < 0.4, 0.3 < c < 0.9, 0 < d<0.2, and a + b + c + d = l . Particularly preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.1 < a < 0.6, 0 < b < 0.3, 0.4 < c < 0.9, 0 < d <0.2, and a + b + c + d = l .

[0041] Acids that may be used are exemplified by hydrochloric acid, acetic acid, formic acid, nitric acid, oxalic acid, sulfuric acid, phosphoric acid, polyphosphoric acid, polycarboxylic acid, trifluoromethane sulfonic acid, and ion exchange resins. Further, the utilized base is exemplified by potassium hydroxide, sodium hydroxide, or similar inorganic bases; and triethylamine, diethylamine, monoethanolamine, diethanolamine, triethanolamine, ammonia water, tetramethylammonium hydroxide, alkoxysilanes having an amino group, aminopropyltrimethoxysilane, or similar organic base compounds.

[0042] Furthermore, an organic solvent may be used in the preparation method. The_ utilized organic solvent is exemplified by ethers, ketones, acetates, aromatic or aliphatic hydrocarbons, γ-butyrolactone, or the like; and mixtures of two or more types of such solvents. Preferred organic solvents are exemplified by propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, γ-butyrolactone, toluene, and xylene.

[0043] In order to accelerate the hydrolysis and condensation reaction of each of the components in the preparation method, water or a mixed solution of water and alcohol is preferably added. Methanol and ethanol are preferred examples of the alcohol. If an organic solvent is used and this reaction is promoted by heating, the reaction is preferably performed at the reflux temperature of the organic solvent.

[0044] Moreover, another preparation method of the organopolysiloxane is

characterized as, in the presence of an acid, performing hydrolysis and condensation reaction of a silane compound (I) represented by the general formula:

R³SiX₃

a disiloxane (V) represented by the general formula:

R⁶ ₃SiOSiR⁶ ₃

and/or a silane compound (VI) represented by the general formula:

R⁶ ₃SiX [0045] The silane compound (I) represented by the general formula:

R³SiX₃

is a raw material for introducing a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group to the obtained organopolysiloxane. In the formula, R³ is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and examples thereof are the same as the groups described above. Moreover, X is an alkoxy group, an acyloxy group, a halogen atom, or a hydroxyl group; and examples thereof are the same as the groups described above. Examples of such silane compound (I) are the same as the compounds described above.

[0046] Moreover, the disiloxane (V) represented by the general formula:

R⁶ ₃SiOSiR⁶ ₃

is a raw material for introducing M units of siloxane in the obtained organopolysiloxane. In the formula, R⁶ are alkyl groups, phenyl groups or hydrogen atoms. Examples of the alkyl group for R⁶ include a methyl group, an ethy^group^and a propyLgroup_^

[0047] This type of disiloxane (V) is exemplified by 1 , 1 ,3,3-tetramethyldisiloxane,

1 ,3-diphenyl- 1 ,3-dimethyldisiloxane, 1 , 1 ,3 ,3 ,3-pentamethyldisiloxane, 1 ,3-diphenyl- 1,3,3- trimethyldisiloxane, 1,3-diphenyl-tetramethyldisiloxane, and hexamethyldisiloxane; and this disiloxane (V) is preferably a disiloxane having a silicon-bonded hydrogen atom.

[0048] The silane compound (VI) represented by the general formula:

R⁶ ₃SiX

is also a raw material for introducing M units of siloxane in the obtained

organopolysiloxane. In the formula, R⁶ is synonymous with the groups described above. In the formula, X is synonymous with the groups described above.

[0049] This type of silane compound (VI) is exemplified by dimethylmethoxysilane, methylphenylmethoxysilane, diphenylmethoxysilane, dimethylethoxysilane,

methylphenylethoxysilane, diphenylethoxysilane, trimethylmethoxysilane,

dimethylphenylmethoxysilane, or similar alkoxysilanes; dimethylacetoxysilane, methylphenylacetoxysilane, diphenylacetoxysilane, trimethylacetoxysilane,

dimethylphenylacetoxysilane, or similar acyloxysilanes; dimethylchlorosilane,

methylphenylchlorosilane, diphenylchlorosilane, trimethylchlorosilane,

methylphenylchlorosilane, or similar halosilanes; and dimethylsilanol,

methylphenylsilanol, diphenylsilanol, or similar silanols. The silane compound (VI) is preferably a silane compound having a silicon-bonded hydrogen atom. [0050] As may be required, a silane compound (VII) of the general formula:

may be reacted in the preparation method. In the formula, R⁶ is synonymous with the groups described above. In the formula, X is synonymous with the groups described above. In the formula, "n" are integers from 2 to 4.

[0051] This type of silane compound (VII) is exemplified by trimethylmethoxysilane, trimethylethoxysilane, methyldiphenylmethoxysilane, methyldiphenylethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, or similar alkoxysilanes; trimethylacetoxysilane, methyldiphenylacetoxysilane,

acetoxysilanes; trimethylchlorosilane, methyldiphenylchlorosilane,

methyldiphenylchlorosilane, dimethyldichlorosilane, methylphenyldichlorosilane, diphenyldichlorosilane, methyltrichlorosilane, phenyltrichlorosilane, tetrachlorosilane, or similar halosilanes; and trimethylsilanol, methyldiphenylsilanol, dimethyldihydroxysilane, methylphenyldihydroxysilane, diphenyldihydroxysilane, methyltrihydroxysilane, phenyltrihydroxysilane, or similar hydroxysilanes.

[0052] Furthermore, at least one component among components (V) to (VII) used in the reaction of the preparation method must have a silicon-bonded hydrogen atom.

[0053] The preparation method is characterized in that a hydrolysis and condensation reaction, in the presence of an acid, is performed using the silane compound (I), the disiloxane (V) and/or the silane compound (VI), and as may be required, the silane compound (VII). The charged ratio of each of the components is the ratio such that the obtained organopolysiloxane has the average unit formula below:

(R⁶ ₃Si0_1/2)_a (R⁶ ₂Si0_2/2)_b (R⁷Si0_3/2)_c (Si0_4/2)_d

[0054] That is to say, in the formula, R⁶ is a group synonymous with the groups described above. R⁷ is a group represented by R³ or is a group represented by R⁶.

7 7

However, at least one R or R in a molecule is a hydrogen atom. At least one R in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Further, in the formula, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d<0.2, and

a + b + c + d = 1. Preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.05 < a < 0.7, 0 < b < 0.4, 0.3 < c < 0.9, 0 < d <0.2, and a + b + c + d = l . Particularly preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.1 < a < 0.6, 0 < b < 0.3, 0.4 < c < 0.9, 0 < d< 0.2, and a + b + c + d = l .

[0055] Acids that may be used are exemplified by hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, trifluoromethane sulfonic acid, or similar strong acids; acetic acid, formic acid, oxalic acid, polycarboxylic acid, or similar carboxylic acids; and acetic acid anhydride, or similar carboxylic acid anhydrides.

[0056] An organic solvent may be used in the preparation method. Examples of the utilized organic solvent are the same as the solvents described above.

[0057] In order to accelerate the hydrolysis and condensation reaction of each of the components in the preparation method, water or a mixed solution of water and alcohol is preferably added. Methanol and ethanol are preferred examples of the alcohol. If an organic solvent is used and this reaction is promoted by heating, the reaction is preferably performed at the reflux temperature of the organic solvent.

[0058] The present coating agent is composed of a curable silicone composition comprising the above described organopolysiloxane. Although no particular limitation is placed on the curing mechanism, curing is performed by a reaction exemplified by hydrosilylation reactions, condensation reactions, and radical reaction using organic peroxides. The curing mechanism is preferably a hydrosilylation reaction due to rapid curing.

[0059] For example, if the organopolysiloxane having the condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group has an alkenyl group, the coating agent composed of this hydrosilylation reaction silicone composition is exemplified by coating agents comprising:

(A) an organopolysiloxane represented by the average unit formula:

(R"₃Si0_1/2)_a (R^{l l} ₂Si0_2/2)_b (R²¹Si0_3/2)_c (Si0_4/2)_d

wherein R." are alkyl groups, alkenyl groups, or phenyl groups; R²¹ are groups recited for R¹ ', condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one R^{1 1} or R²¹ in a molecule is an alkenyl group and at least one R in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = 1 ; (B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; and

(C) a hydrosilylation reaction catalyst.

[0060] The organopolysiloxane for component (A) is represented by the average unit formula:

[0061 J In the formula, R^{1 1} are alkyl groups, alkenyl groups, or phenyl groups.

Examples of the alkyl group for R^{1 1} include the same groups described for R¹. Of these, a methyl group is preferable. Examples of the alkenyl group for R^{1 1} include the same groups described for R¹. Of these, a vinyl group is preferable.

[0062] Moreover, in the formula, R²¹ is the group represented by R¹ ', or is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Examples of the alkyl group for R include the same groups described for R¹. Examples of the alkenyl group for R²¹ include the same groups described for R¹. Examples of the condensed polycyclic aromatic group for R ¹ include a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and such condensed polycyclic aromatic groups where a hydrogen atom is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The condensed polycyclic aromatic group for R²¹ is preferably the naphthyl group. Examples of the group including a condensed polycyclic aromatic group for R²¹ include alkyl groups including a condensed polycyclic aromatic group such as a naphthyl ethyl group, a naphthyl propyl group, an anthracenyl ethyl group, a phenanthryl ethyl group, a pyrenyl ethyl group, and the like; and such groups where a hydrogen atom in the condensed polycyclic aromatic group is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The group including a condensed polycyclic aromatic group for R²¹ is particularly preferably the naphthyl ethyl group. An organopolysiloxane where R²¹ is an alkyl groups including a condensed polycyclic aromatic group has relatively low viscosity and has the effect of making possible the lowering of viscosity of the present coating agent.

[0063] Furthermore, in the formula, at least one R^{1 1} or R²¹ in a molecule is an alkenyl group. Moreover, in the formula, at least one R²¹ in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Preferably at least 50 mol% of R²¹ in a molecule are condensed polycyclic aromatic groups or groups including condensed polycyclic aromatic groups.

[0064] Further, in the formula, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d <0.2, and a + b + c + d = l .

Preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.05 < a < 0.7, 0 < b < 0.4, 0.3 < c < 0.9, 0 < d<0.2, and a + b + c + d = l . Particularly preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.1 < a < 0.6, 0 < b < 0.3,

0.4 < c < 0.9, 0 < d <0.2, and a + b + c + d = l . When "a" is less than the lower limit of the range described above, handling and processability of the obtained composition declines. On the other hand, transparency of the obtained cured product declines if "a" exceeds the upper limit of the range described above. Further, stickiness of the obtained cured product occurs when "b" exceeds the upper limit of the range described above. Further, refractive index of the cured product may markedly decline if "c" is less than the lower limit of the range described above. On the other hand, the cured product becomes excessively rigid and brittle if "c" exceeds the upper limit of the range described above. Further, the cured product becomes extremely rigid and brittle if "d" exceeds the upper limit of the range described above.

[0065] Although component (A) is represented by the above average unit formula, a small amount of the hydroxyl groups or methoxy groups, ethoxy groups, or the like alkoxy groups may be bonded to silicon atoms in the molecule. Component (A) having silicon- bonded hydroxyl groups or silicon-bonded alkoxy groups may result in improved adhesivity of the present coating agent, may result in improved adhesion of the cured product of the coating agent to the substrate, or may result in improvement of compatibility with other components included in the present coating agent.

[0066] No particular limitation is placed on the organopolysiloxane of component (B) as long as the organopolysiloxane has a silicon-bonded hydrogen atom. The bonding position of the silicon-bonded hydrogen atom in component (B) is exemplified by molecular chain terminal silicon atoms and/or silicon atoms in the molecular chain. The other groups bonded to the silicon atom in component (B) are exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or similar alkyl groups; a phenyl group, a tolyl group, a xylyl group, a naphthyl group, or similar aryl groups; a benzyl group, a phenethyl group, or similar aralkyl groups; and a chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, or similar halogenated alkyl groups; and such other groups are preferably the methyl group or phenyl group. Component (B) may have a straight, branched, cyclic, net-like, or a partially branched straight chain molecular structure.

[0067] This type of organopolysiloxane for component (B) is exemplified by a methylhydrogenpolysiloxane capped at both molecular terminals with trimethylsiloxy groups, a copolymer of dimethylsiloxane and methylhydrogensiloxane capped at both molecular terminals with trimethylsiloxy groups, a copolymer of dimethylsiloxane, methylhydrogensiloxane, and methylphenylsiloxane capped at both molecular

terminals with trimethylsiloxy groups, a dimethylpolysiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups, a copolymer of dimethylsiloxane and methylphenylsiloxane capped at both molecular terminals with dimethylhydrogensiloxy groups, a methylphenylpolysiloxane capped at both molecular terminals with

dimethylhydrogensiloxy groups, organopolysiloxane copolymers composed of siloxane units represented by the general formula R'₃SiOi_/2 and siloxane units represented by the general formula R'₂HSiOi/₂ and siloxane units represented by the formula S1O4/2,

organopolysiloxane copolymers composed of siloxane units represented by the general formula R'₂HSiOi_/2 and siloxane units represented by the formula Si0_4/2,

organopolysiloxane copolymers composed of siloxane units represented by the general formula R'HSi0₂/₂, organopolysiloxane copolymers composed of siloxane units represented by the general formula R'Si0_3/2 or siloxane units represented by the formula HSi0_3/2, and mixtures of two or more such organopolysiloxanes. Furthermore, R' in the formula is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or a similar alkyl group; a phenyl group, a tolyl group, a xylyl group, naphthyl group, or a similar aryl group; a benzyl group, a phenethyl group, or similar aralkyl group; or a chloromethyl group, a 3-chloropropyl group, a 3,3,3- trifluoropropyl group, or a similar halogenated alkyl group.

[0068] Examples of hydrosilylation reaction catalyst for component (C) include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts.

Platinum-based catalysts are preferred due to the ability to remarkably promote curing of the present coating agent. Examples of the platinum-based catalyst include a platinum fine powder, chloroplatinic acid, an alcohol solution of chloroplatinic acid, a platinum- alkenylsiloxane complex, a platinum-olefm complex and a platinum-carbonyl complex, with a platinum-alkenylsiloxane complex being preferred.

[0069] In another coating agent of the present invention, for example, if the organopolysiloxane having a condensed polycyclilc aromatic group or a group including a condensed polycyclic aromatic group has a silicon-bonded hydrogen atom, the coating agent is exemplified by a coating agent comprising:

(D) an organopolysiloxane represented by the average unit formula:

(R¹² ₃Si0_1/2)a (R¹² ₂Si0_2/2)_b (R²²Si0_3/2)c (Si0_4/2)d

wherein R¹² are alkyl groups, phenyl groups, or hydrogen atoms; R²² are groups recited for R , condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one R^, or R in a molecule is a hydrogen atom and at least one R in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = 1 ;

(E) an organopolysiloxane having at least two alkenyl groups in a molecule; and

(C) a hydrosilylation reaction catalyst.

[0070] The organopolysiloxane for component (D) is represented by the average unit formula:

(R^l2 ₃Si0_1/2)_a(R¹² ₂Si0_2/2)_b (R²²Si0_3/2)_c (Si0₄/₂)_d

[0071] In the formula, R¹² are alkyl groups, phenyl groups or hydrogen atoms.

Examples of the alkyl group for R¹² include the same groups described for R¹. Of these, the methyl group is preferable.

[0072] Moreover, in the formula, R²² is represented by R¹², or is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Examples of the alkyl group for R²² include the same groups described for R^l. Examples of the condensed polycyclic aromatic group for R²² include a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, and such condensed polycyclic aromatic groups where a hydrogen atom is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; by an alkoxy group such as a methoxy group, an ethoxy group, and the like; or by a halogen atom such as a chlorine atom, a bromine atom, and the like. The condensed polycyclic aromatic group is preferably the naphthyl group. Examples of the alkyl group including a condensed polycyclic aromatic group for R²² include alkyl groups containing condensed polycyclic aromatic groups such as a naphthyl ethyl group, a naphthyl propyl group, an anthracenyl ethyl group, a phenanthryl ethyl group, a pyrenyl ethyl group, and the like, and such groups where a hydrogen atom of the condensed polycyclic aromatic group is replaced by an alkyl group such as a methyl group, an ethyl group, and the like; an alkoxy group such as a methoxy group, an ethoxy group, and the like; or a halogen atom such as a chlorine atom, a bromine atom, and the like. Of these, an alkyl group including a condensed polycyclic aromatic group is preferable, and the naphthyl ethyl group is particularly preferable. Organopolysiloxanes where R²² is an alkyl group including a condensed polycyclic aromatic group have relatively low viscosity and have the effect of making it possible to lower viscosity of the present coating agent.

[0073] Furthermore, in the formula, at least one R or R in a molecule is the hydrogen atom. Moreover, in the formula, at least one R in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group. Preferably at least 50 mol% of R²² in a molecule are condensed polycyclic aromatic groups or groups including a condensed polycyclic aromatic group.

[0074] Further, in the formula, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d <0.2, and a + b + c + d = l .

Preferably, "a", "b", "c", and "d" are numbers that rspectively satisfy: 0.05 < a < 0.7, 0 < b < 0.4, 0.3 < c < 0.9, 0 < d<0.2, and a + b + c + d = l . Particularly preferably, "a", "b", "c", and "d" are numbers that respectively satisfy: 0.1 < a < 0.6, 0 < b < 0.3,

0.4 < c < 0.9, 0 < d <0.2, and a + b + c + d = l . When the value of "a" is below the lower limit of the range described above, handling and processability of the present coating agent declines. On the other hand, transparency of the cured product declines if "a" exceeds the upper limit of the range described above. Further, stickiness of the cured product occurs when "b" exceeds the upper limit of the range described above. Further, refractive index of the cured product may markedly decline if "c" is less than the lower limit of the range described above. On the other hand, the cured product becomes excessively rigid and brittle if "c" exceeds the upper limit of the range described above. Further, the cured product becomes extremely rigid and brittle if "d" exceeds the upper limit of the range described above.

[0075] Although component (D) is represented by the above average unit formula, a small amount of the hydroxyl groups or methoxy groups, ethoxy groups, or the like alkoxy groups may be bonded to silicon atoms in the molecule. Component (D) having silicon- bonded hydroxyl groups or silicon-bonded alkoxy groups may result in improved adhesivity of the present coating agent, may result in improved adhesion of the cured product of the coating agent to the substrate, or may result in improvement of compatibility with other components included in the present coating agent.

[0076] No particular limitation is placed on the organopolysiloxane for component (E) as long as it has an alkenyl group. Examples of the alkenyl group in component (E) include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group. Of these, a vinyl group is preferable. Groups bonding to silicon atom other than alkenyl groups in component (E) are exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, or a similar alkyl group; a phenyl group, a tolyl group, a xylyl group, a naphthyl group, or a similar aryl group; a benzyl group, a phenethyl group, or a similar aralkyl group; and a chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, or a similar halogenated alkyl group; and the groups are preferably the methyl group or phenyl group. Component (E) may have a straight, branched, cyclic, net-like, or a partially branched straight chain molecular structure.

[0077] This type of organopolysiloxane for component (E) is exemplified by a copolymer of dimethylsiloxane and methylvinylsiloxane capped at both molecular terminals with trimethylsiloxy groups, methylvinylpolysiloxane capped at both molecular terminals with trimethylsiloxy groups, copolymer of dimethylsiloxane,

methylvinylsiloxane, and methylphenylsiloxane capped at both molecular terminals with trimethylsiloxy groups, dimethylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups, methylvinylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups, copolymers of dimethylsiloxane and methylvinylsiloxane capped at both molecular terminals with dimethylvinylsiloxy groups, copolymer of dimethylsiloxane, methylvinylsiloxane, and methylphenylsiloxane capped at both molecular terminals with dimethylvinylsiloxy groups, organopolysiloxane copolymers composed of siloxane units represented by the general formula R'₃SiOi_/2 and siloxane units represented by the general formula R'2R"SiOi_/2 and siloxane units represented by the formula Si04₂, organopolysiloxane copolymers composed of siloxane units represented by the general formula R'₂R"SiOi_/2 and siloxane units represented by the formula Si0_4/2, organopolysiloxane copolymers composed of siloxane units represented by the general formula R'R"Si02/2, and siloxane units represented by the general formula R'Si03_/2 or siloxane units represented by the general formula R"Si03_/2, and mixtures of two or more such organopolysiloxanes. Furthermore, R' in the formula is synonymous with the groups described above. Furthermore, R" in the formula is an alkenyl group and is exemplified by a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group.

[0078] Examples of the hydrosilylation-reaction catalyst include those described above.

[0079] A coating agent may be prepared that comproses components (A), (D), and (C). Components (A), (D), and (C) are as described above.

[0080] Although no particular limitation is placed on the content of the

organopolysiloxane having the silicon-bonded hydrogen atom, this amount preferably results in the mole ratio of silicon-bonded hydrogen atoms relative to alkenyl groups in the present coating agent being in the range of 0.1 to 5, and particularly preferably in the range of 0.5 to 2.

[0081] Although no particular limitation is placed on the content of component (C) as long as there is an amount sufficient to promote curing of the present coating agent.

Specifically, the content of component (C) in the present coating agent, based on the catalyst metals in component (C), is preferably in the range of 0.01 to 500 ppm, further preferably result in the range of 0.01 to 100 ppm, and particularly preferably result in the range of 0.01 to 50 ppm in terms of mass units.

[0082] Moreover, the present coating agent may include an adhesion-imparting agent for improvement of the adhesivity of the present coating agent. Preferred adhesion- imparting agents are organosilicon compounds having at least one alkoxy group bonded to a silicon atom in a molecule. This alkoxy group is exemplified by a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a methoxyethoxy group; and the methoxy group is particularly preferred. Moreover, groups bonding to a silicon atom other than alkoxy groups in this organosilicon compound are exemplified by substituted or non-substituted monovalent hydrocarbon groups such as alkyl groups, alkenyl groups, aryl groups, aralkyl groups, halogenated alkyl groups, and the like; epoxy group-containing monovalent organic groups such as 3-glycidoxypropyl groups, 4-glycidoxybutyl groups, or similar glycidoxyalkyl groups; 2-(3,4-epoxycyclohexyl)ethyl groups, 3 -(3, 4- epoxycyclohexyl)propyl groups, or similar epoxycyclohexylalkyl groups; and 4- oxiranylbutyl groups, 8-oxiranyloctyl groups, or similar oxiranylalkyl groups; acrylic group-containing monovalent organic groups such as 3-methacryloxypropyl groups, and the like; and hydrogen atoms. This organosilicon compound preferably has a silicon- bonded alkenyl group or silicon-bonded hydrogen atom. Moreover, due to the ability to impart good adhesion with respect to various types of substrates, this organosilicon compound preferably has at least one epoxy group-containing monovalent organic group in a molecule. This type of organosilicon compound is exemplified by organosilane compounds, organosiloxane oligomers and alkyl silicates. Molecular structure of the organosiloxane oligomer or alkyl silicate is exemplified by a linear structure, partially branched linear structure, branched chain structure, ring-shaped structure, and net-shaped structure. A linear chain structure, branched chain structure, and net-shaped structure are particularly preferred. This type of organosilicon compound is exemplified by silane compounds such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxy propyltrimethoxy silane, and the like; siloxane compounds having at least one of silicon-bonded alkenyl groups or silicon- bonded hydrogen atoms, and at least one silicon-bonded alkoxy group in a molecule;

mixtures of a silane compound or siloxane compound having at least one silicon-bonded alkoxy group and a siloxane compound having at least one silicon-bonded hydroxyl group and at least one silicon-bonded alkenyl group in a molecule; and methyl polysilicate, ethyl polysilicate, and epoxy group-containing ethyl polysilicate.

[0083] Although no particular limitation is placed on the content of this adhesion- imparting agent, the concentration relative to 100 parts by weight of the total present coating agent is preferably in the range of 0.01 to 10 parts by weight.

[0084] A reaction inhibitor, for example, an alkyne alcohol such as 2-methyl-3-butyn- 2-ol, 3,5-dimethyl-l-hexyn-3-ol and 2-phenyl-3-butyn-2-ol; an ene-yne compound such as 3-methyl-3-penten-l -yne and 3,5-dimethyl-3-hexen-l-yne; or l ,3,5,7-tetramethyl-l ,3,5,7- tetravinylcyclotetrasiloxane, 1 ,3,5,7-tetramethyl-l ,3,5,7-tetrahexenylcyclotetrasiloxane or a benzotriazole may be incorporated as an optional component in the present coating agent.

[0085] A content of the reaction inhibitor is not limited, but is preferably from 0.0001 to 5 parts by weight per 100 parts by weight of the present coating agent.

[0086] Moreover, the present coating agent may include as an additional optional component a phosphor. This phosphor is exemplified by substances widely used in light emitting diodes (LED), such as yellow, red, green, and blue light-emitting phosphors such as oxide type phosphors, oxynitride type phosphors, nitride type phosphors, sulfide type phosphors, oxysulfide type phosphors, and the like. The oxide type phosphor is exemplified by cerium ion-containing yttrium, aluminum, and garnet type YAG type green colored to yellow colored light emitting phosphors; cerium ion-containing terbium, aluminum, and garnet based TAG type yellow colored light emitting phosphors; and cerium or europium-ion containing silicate-based green to yellow light emitting phosphors. The oxynitride type phosphor is exemplified by europium ion-containing silicon, aluminum, oxygen, and nitrogen type, or sialon type, red to green colored light emitting phosphors. The nitride type phosphor is exemplified by europium ion-containing calcium strontium, aluminum, silicon, and nitrogen type, or CASN type, red light emitting phosphors. The sulfide type phosphor is exemplified by copper ion-containing or aluminum ion-containing ZnS type green light emitting phosphors. The oxysulfide type phosphor is exemplified by europium ion-containing Y₂0₂S type red light emitting phosphors. These phosphors may be used as one type or as a mixture of two or more types.

[0087] The content of this phosphor in the present coating agent is not limited, but is preferably in the range of 0.1 to 70 wt.%, and further preferably is in the range of 1 to 20 wt.%.

[0088] An inorganic filler such as silica, glass, alumina, zinc oxide and the like; an organic resin fine powder of a polymethacrylate resin and the like; a heat-resistant agent, a dye, a pigment, a flame retardant, a solvent and the like may be incorporated as optional components in the coating agent at levels that do not impair the objective of the present invention.

[0089] Although the curing of the coating agent progresses at room temperature or due to heating, the coating agent preferably is heated to cause rapid curing. The heating temperature is preferably from 50 to 200°C.

[0090] The electrical-electronic equipment of the present invention will be explained in detail.

[0091] The electrical-electronic equipment of the present invention is characterized in that the electrical-electronic equipment is covered by a cured product of the coating agent. In particular, a metal part of electrical-electronic equipment is covered by a cured product of the coating agent. This type of electrical-electronic equipment is exemplified by plasma displays, liquid crystal displays, organic electroluminescent displays, and LEDs. The metal part of this type of electrical-electronic equipment is exemplified by electrodes, electrical circuits on circuit boards, and LED reflectors. Metals of this type of metal part of concern due to corrosion by a corrosive substance are exemplified by silver, copper, aluminum, and alloys of such metals.

[0092] The method of the present invention for protecting a metal part of electrical- electronic equipment is next explained in detail.

[0093] The method of the present invention is a method that suppresses corrosion by applying the coating agent onto a metal part of electrical-electronic equipment exposed to a corrosive substance, and thereafter cures the coating agent to suppress corrosion of the metal part by the corrosive substance. This electrical-electronic equipment is exemplified by plasma displays, liquid crystal displays, organic electroluminescent displays, and LEDs. The metal part of this type of electrical-electronic equipment is exemplified by electrodes, electrical circuits on circuit boards, and LED reflectors. Metals of this type of metal part of concern due to corrosion by a corrosive substance are exemplified by silver, copper, aluminum, and alloys of such metals.

[0094] Moreover, the corrosive substance is exemplified by sulfur and sulfur- containing compounds. Examples of such sulfur-containing compounds include hydrogen sulfide, sulfur dioxide gas, sulfuric acid mist, and mercaptan gases. Such corrosive substances are often present in the environment during use or manufacture of electrical-electronic equipment and parts thereof. Also, such corrosive substances may be generated from such internal parts or materials during the use of the electrical-electronic equipment.

[0095] According to the method of the present invention, firstly the coating agent is applied to the metal part of the electrical-electronic equipment exposed to the corrosive substance. Prior to application of the coating agent, as may be required, the current- conducting part may be cleaned. Moreover, the application method of the coating agent is not limited, and this application method is exemplified by application by a dispenser, application by a scraper, and application by a brush.

[0096] According to the method of the present invention, no limitation is placed on the thickness of the coating agent applied to the metal part. However, this thickness is preferably within the range of 100 μπι to 5 mm. When the thickness of the coating agent applied to the metal part is less than the lower limit described above, the obtained cured product cannot sufficiently suppress corrosion of the metal part by the corrosive substance. On the other hand, even if the upper limit of the range described above is exceeded, a marked improvement effect is not seen in the suppression of corrosion of the metal part due to the corrosive substance.

[0097] According to the method of the present invention, next, the coating agent is cured. Although no limitation is placed on the curing conditions, curing at room temperature is preferred in order not to heat the electrical-electronic equipment. Of course, curing of the coating agent is promoted by heating. If the coating agent is cured at room temperature, curing is preferably allowed to take place for several minutes to about 1 week.

Examples

[0098] The coating agent, electrical-electronic equipment, and method for protecting a metal part of an electrical-electronic equipment of the present invention will be explained using Practical and Comparative Examples. In the formulae, Me, Ph, Vi, and Naph respectively represent methyl group, phenyl group, vinyl group, and naphthyl group.

Copper-plate-corrosion -test and LED-corrosion-test-were perfOrmed in the following manner.

[0099]

[Copper Plate Corrosion Test]

The surface of a copper plate was sanded using sandpaper, and then was washed using acetone. Thereafter, the coating agent was applied at 1 mm thickness, and the coated copper plate was heated for 60 minutes in an oven at 150°C to cure the coating and produce the test piece. This test piece was inserted in a hermetically sealable glass container of 450 mL volume containing 0.3 ± 0.03 g of sulfur. After the system was allowed to sit for 51 hours at 80°C, the test piece was removed from the glass container, the cured coating was removed using xylene, and corrosion state of the test piece copper plate was observed. Degree of discoloration of the post-corrosion-test copper plate was observed and evaluated as follows: o = no discoloration, Δ = slight discoloration, and ^χ = severe discoloration.

[0100]

[LED Corrosion Test]

A LED chip with 1 mm ^χ 1 mm square size (MKO 4545C manufactured by

Bridgelux Inc.) was placed on a central die mount part of a LED lead frame with 5 mm ^χ 5 mm square size (TTI-5074 manufactured by I-Chiun Precision Industry Co., Ltd.) surrounded by a polyphthalamide (PPA) resin case. Thereafter, the LED chip and inner leads were electrically connected by gold bonding wires with 1.5 mil diameter to produce an LED.

[0101] 14.5 mg of the coating agent was injected into the polyphthalamide (PPA) resin case of this LED, and the assembly was cured for 1 hour at 150°C to produce an LED in which the LED chip and inner leads were covered.

[0102] Thereafter, this LED was placed in a hermetically sealable glass container of 450 mL volume containing 1.2 g of sulfur. After the container was allowed to sit for 1 16 hours or 428 hours at 80°C, 150 mA of electrical current was passed through the LED using a 2600 Sourcemeter manufactured by Keithley Instruments Inc. Light intensity of the LED was measured using an ISP 250 (250 mm) integrating sphere and a CAS- 140 CT spectrometer (both manufactured by Instrument Systems GmbH). Furthermore, comparison was made by taking the pre-test light emission intensity to be 100%.

Furthermore, a microscope was used to observe the external appearance of the LED in the corrosion test.

[0103]

[Reference Example 1 ]

Firstly, 10 g (40.3 mmol) of 1 -naphthyltrimethoxysilane, 1.2 g (5.6 mmol) of methyldiphenylsilanol, 3.3 g (10.6 mmol) of l ,3-divinyl-l,3-diphenyl dimethyl disiloxane, and 20 g of toluene were placed in a reaction vessel and were premixed. Thereafter, 2.2 g (122.1 mmol) of water and 10 g of methanol were added, and while stirring, 0.069 g (0.46 mmol) of trifluoromethane sulfonic acid was added. The mixture was heated and refluxed for 2 hours. Thereafter, the mixture was distilled at atmospheric pressure by heating until a temperature of 85°C was reached. The mixture was reacted for 1 hour at this temperature. Thereafter, 0.06 g of potassium hydroxide (1.1 mmol) was added, and atmospheric pressure distillation was performed while heating to a reaction temperature of 120°C. The mixture was reacted for 1 hour at this temperature. The system was cooled down to room temperature, and then 0.07 g (1.2 mmol) of acetic acid was added to perform the neutralization reaction. The generated salt was removed by filtration. The low boiling point substances were removed from the obtained transparent solution by heating under vacuum to obtain 10.0 g (85.5% yield) of a colorless transparent rubber-like viscous liquid.

[0104] As a result of NMR analysis, this liquid was found to be the

organopolysiloxane represented by the average unit formula: (MePh₂Si0_1/2)o.o8 (MePhViSiOi_/2)₀.₃2 (NaphSiO_3/2)_{0 60}

Weight average molecular weight (Mw) of this organopolysiloxane was 1 ,000.

Dispersivity (Mw/Mn) was 1.1 1. Refractive index was 1.623.

[0105]

[Reference Example 2]

Firstly, 50 g (201.3 mmol) of 1 -naphthyltrimethoxysilane, 20.9 g (67.3 mmol) of l,3-divinyl-l ,3-diphenyldimethyldisiloxane, and 100 g of toluene were placed in a reaction vessel and were premixed. Thereafter, 12.0 g (666.1 mmol) of water and 50 g of methanol were added, and while stirring, 0.345 g (2.3 mmol) of trifluoromethane sulfonic acid was added. The mixture was heated and refluxed for 2 hours. Thereafter, the mixture was distilled at atmospheric pressure by heating until a temperature of 85 °C was reached. The mixture was reacted for 1 hour at this temperature. Thereafter, 0.30 g (5.4 mmol) of potassium hydroxide was added, and atmospheric pressure distillation was performed while heating to a reaction temperature of 120°C. The mixture was reactedTor 1 hour at this temperature. The system was cooled down to room temperature, and then 0.40 g (6.7 mmol) of acetic acid was added to perform the neutralization reaction. The generated salt was removed by filtration. The low boiling point substances were removed from the obtained transparent solution by heating under vacuum to obtain 56.7 g (99.3% yield) of a colorless transparent viscous liquid.

[0106] As a result of NMR analysis, this viscous liquid was found to be the organopolysiloxane represented by the following average unit formula:

(MeViPhSi0_{1 2})o.4o (NaphSi0_3/2)₀.₆₀

Weight average molecular weight (Mw) of this organopolysiloxane was 1 ,100.

Dispersivity (Mw/Mn) was 1.12. Refractive index was 1.622.

[0107]

[Reference Example 3]

Firstly, 50 g (201 mmol) of 1 -naphthyltrimethoxysilane was loaded into a reaction vessel and was heated and melted. Thereafter, 0.06 g (0.4 mmol) of trifluoromethane sulfonic acid was added. While the system was heated to 45 to 50°C, 9.3 g (154.9 mmol) of acetic acid was added in a drop- wise manner. After completion of drop- wise addition, the mixture was heated and stirred for 30 minutes at 50°C. The mixture was heated and low boiling point substances were distilled at atmospheric pressure until the reaction temperature reached 80°C. Thereafter, the mixture was cooled down to room temperature. 24.4 g (181.6 mmol) of 1 , 1 ,3,3-tetramethyldisiloxane was added in a drop- wise manner, and the mixture was heated to reach a reaction temperature of 45°C.

Thereafter, 18 g of acetic acid was added drop-wise at 45 to 50°C. After completion of drop-wise addition, the mixture was heated and stirred for 30 minutes at 50°C. While the system was maintained at a temperature of 60°C or less by air or water cooling, 15.5 g (151.8 mmol) of acetic acid anhydride was added in a drop-wise manner. After completion of drop- wise addition, the mixture was heated and stirred for 30 minutes at 50°C. Thereafter, toluene and water were added, the mixture was stirred, and the mixture was allowed to sit. The water washing was performed while repeatedly removing the lower layer. After confirming that pH of the lower layer was 7, the upper layer (i.e. toluene layer) was heated and distilled under vacuum to remove low boiling point substances. 43 g of colorless transparent liquid was obtained (76.0% yield).

[0108] As a result of NMR analysis, this liquid was found to be an organopolysiloxane of the following average unit formula:

(HMe₂SiOi_/2)o.₅₉ (NaphSiO_3/2)₀₄i

Weight average molecular weight (Mw) of this organopolysiloxane was 660.

Dispersivity (Mw/Mn) was 1.05. Refractive index was 1.548.

[0109]

[Practical Example 1]

4.01 g of the organopolysiloxane prepared in Reference Example 1 and represented by the average unit formula:

(MePh₂SiO,/₂)o.o8 (MePhViSiO,_/2)o.₃₂ (NaphSiO_3/2)₀.₆₀

1.77 g of an organopolysiloxane represented by the average formula:

HMe₂SiO(Ph₂SiO)_{2 5} SiMe₂H

0.33 g of the organopolysiloxane prepared in Reference Example 3 and represented by the average unit formula:

(HMe₂SiO 1/2)0.59 ( aphSi0₃/₂)o.₄i

0.038 g of cyclic methylvinylsiloxane, and a 1 ,3-divinyltetramethyl disiloxane solution of a 1 ,3-divinyltetramethyl disiloxane platinum complex (used in the composition in such an amount that in terms of weight units the content of the platinum was 2 ppm) were uniformly mixed to prepare the coating agent.

[0110] This coating agent was used to perform corrosion test of a copper plate prepared in the aforementioned manner. Moreover, corrosion test was performed using an LED produced in the aforementioned manner using this coating agent. Results of this test are shown in Table 1. Moreover, the change of appearance of the LED over time during corrosion test is shown in Figure 3.

[0111]

[Practical Example 2]

12 g of the organopolysiloxane prepared in Reference Example 2 and represented by the average unit formula:

(MeViPhSiO_1/2)₀.₄₀ (NaphSi0_3/2)o.₆₀

5.34 g of an organopolysiloxane represented by the average formula:

HMe₂SiO(Ph₂SiO)_2.5 SiMe₂H

1.8 g of the organopolysiloxane prepared in Reference Example 3 and represented by the average unit formula:

(HMe₂SiO,/₂)₀.₅₉ (NaphSi0_3/2)o.₄,

0.06 g of cyclic methylvinylsiloxane, and a 1 ,3-divinyltetramethyl disiloxane solution of a 1 ,3-divinyltetramethyl disiloxane platinum complex (used in the composition in such an amount that in terms of weight units the content of the platinum was 2 ppm) were uniformly mixed to prepare the coating agent.

[0112] This coating agent was used to perform corrosion test of a copper plate prepared in the aforementioned manner. Moreover, corrosion test was performed using an LED produced in the aforementioned manner using this coating agent. Results of this test are shown in Table 1. Moreover, the change of appearance of the LED over time during corrosion test is shown in Figure 4.

[0113]

[Practical Example 3]

9 g of organopolysiloxane represented by the average formula:

ViMe₂SiO(MePhSiO)₂₅ SiMe₂Vi

1.02 g of the organopolysiloxane prepared in Reference Example 3 and represented by the average unit formula:

(HMe₂SiOi/₂)o.₅₉ (NaphSiO_3/2)₀.4i

0.06 g of cyclic methylvinylsiloxane, and a 1 ,3-divinyltetramethyl disiloxane solution of a 1 ,3-divinyltetramethyl disiloxane platinum complex (used in the composition in such an amount that in terms of weight units the content of the platinum was 2 ppm) were uniformly mixed to prepare the coating agent. [0114] This coating agent was used to perform corrosion test of a copper plate prepared in the aforementioned manner. Figure 1 C shows a photograph of the test piece prior to corrosion test. Figure 2C shows a photograph of the test piece after corrosion test. Moreover, corrosion test was performed using an LED produced in the

aforementioned manner using this coating agent, and results of this test are shown in Table 1. Moreover, the change of appearance of the LED over time during corrosion test is shown in Figure 5.

[0115]

[Comparative Example l]y

4.9 g of an organopolysiloxane represented by the average unit formula:

(Me2ViSi0_1/2)o.₂5 (PhSi0₃/₂)o.7₅

0.65 g of an organopolysiloxane represented by the average unit formula:

(Me₂ViSiO,_/2)o. io (Me3Si0_1/2)o.i₅ (PhSiO_3/2)₀.₇₅

1.5 g of an organopolysiloxane represented by the average formula:

HMe₂SiO(Ph₂SiO)SiMe₂H

0.16 g of an organopolysiloxane represented by the average unit formula:

(HMe₂SiO,_/2)o.₆₀ (PhSi0_3/2)o.40

0.02 g of cyclic methylvinylsiloxane, and a 1 ,3-divinyltetramethyl disiloxane solution of a 1 ,3-divinyltetramethyl disiloxane platinum complex (used in the composition in such an amount that in terms of weight units the content of the platinum was 2 ppm) were uniformly mixed to prepare the coating agent.

[0116] This coating agent was used to perform corrosion test of a copper plate prepared in the aforementioned manner. Figure IB shows a photograph of the test piece prior to corrosion test. Figure 2B shows a photograph of the test piece after corrosion test. Moreover, corrosion test was performed using an LED produced in the

aforementioned manner using this coating agent, and results of this test are shown in Table

1. Moreover, the change of appearance of the LED over time during corrosion test is shown in Figure 6.

[0117]

[Comparative Example 2]

For comparison in the copper plate corrosion test, the surface was sanded using sandpaper, and the sanded surface was washed using acetone, followed by test in the above described manner. Figure 1 A shows a photograph of the test piece prior to corrosion test, and Figure 2A shows a photograph of the test piece after corrosion test. Moreover, for comparison, the coating agent was not applied in the LED corrosion test, and the LED was tested in the above described manner. Results are shown in Table 1.

[0118] Table 1

Industrial Applicability

[0119] The coating agent of the present invention is able to suppress corrosion of metal parts of electrical-electronic equipment caused by a corrosive substance. The coating agent of the present invention is thus suitable as a coating agent of electrical- electronic equipment such as an LED and the like utilizing a metal that is readily corroded, such as copper, silver, aluminum, and the like.

Claims

A coating agent composed of a curable silicone composition comprising an organopolysiloxane having a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group.

The coating agent according to claim 1 , wherein the organopolysiloxane is represented by the average unit formula:

(R^SiC A (R'₂Si0_2/2)_b (R²Si0_3/2)_c (Si0_4/2)_d

1 2 wherein R are alkyl groups, alkenyl groups, phenyl groups, or hydrogen atoms; R are groups recited for R¹, condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one R¹ or R² in a molecule is an alkenyl group or hydrogen atom and at least one R² in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = 1.

The coating agent according to claim 2, wherein, in a molecule, at least 50 mol% of R are the condensed polycyclic aromatic groups or the groups including a condensed polycyclic aromatic group.

The coating agent according to any one of claims 1 to 3, wherein the condensed polycyclic aromatic group is a naphthyl group.

The coating agent according to claim 1 , wherein the curable silicone composition is a hydrosilylation reaction curable silicone composition.

The coating agent according to claim 5, wherein the hydrosilylation reaction curable silicone composition comprises:

(A) an organopolysiloxane represented by the average unit formula:

(R^SiO_!/A CR^SiO^_b (R²¹Si0_3/2)_c (Si0_4/2)_d

wherein R^{1 1} are alkyl groups, alkenyl groups, or phenyl groups; R²¹ are groups recited for R^{1 1}, condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one R^{1 1} or R²¹ in a molecule is an alkenyl group and at least one R²¹ in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy: 0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = 1 ;

(B) an organopolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; and

(C) a hydrosilylation reaction catalyst.

(D) an organopolysiloxane represented by the average unit formula:

(R¹² ₃Si0_1/2)_a (R¹² ₂Si0_2/2)_b (R²²Si0_3/2)_c (Si0_4/2)_d

wherein R¹² are alkyl groups, phenyl groups, or hydrogen atoms; R²² are groups recited for R , condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one R¹² or R²² in a molecule is a hydrogen atom and at least one R²² in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy:

0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = l ;

(E) an organopolysiloxane having at least two alkenyl groups in a molecule; and

(C) a hydrosilylation reaction catalyst.

(A) an organopolysiloxane represented by the average unit formula:

(R"₃SiOi_/2)_a (R¹ '₂Si0_2/2)_b (R²¹Si0_3/2)_c (Si0_4/2)_d

wherein R^{1 1} are alkyl groups, alkenyl groups, or, phenyl groups; R²¹ are groups recited for R^{1 1}, condensed polycyclic aromatic groups, or groups including a condensed polycyclic aromatic group, provided that at least one Rⁿ or R²¹ in a molecule is an alkenyl group and at least one R²¹ in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy:

(D) an organopolysiloxane represented by the average unit formula:

(R¹² ₃Si0_1/2)_a (R¹² ₂Si0₂/₂)_b (R²²Si0₃/₂)_c (Si0₄/₂)d 11 22

wherein R are alkyl groups, phenyl groups, or hydrogen atoms; R are groups recited for R¹², condensed polycyclic aromatic groups, or groups including a

12 22 * condensed polycyclic aromatic group, provided that at least one R or R in a molecule is a hydrogen atom and at least one R²² in a molecule is a condensed polycyclic aromatic group or a group including a condensed polycyclic aromatic group; and "a", "b", "c", and "d" are numbers that respectively satisfy:

0.01 < a < 0.8, 0 < b < 0.5, 0.2 < c < 0.9, 0 < d < 0.2, and a + b + c + d = 1 ; and (C) a hydrosilylation reaction catalyst.

9. An electrical-electronic equipment covered by a cured product of the coating agent described in any one of claims 1 to 8.

10. The electrical-electronic equipment according to claim 9, wherein the

electrical-electronic equipment comprises a metal part.

1 1. The electrical-electronic equipment according to claim 10, wherein the metal part is formed by a metal selected from the group consisting of silver, copper, aluminum, and alloys of such metals.

12. A method for protecting a metal part of an electrical-electronic equipment comprising the steps of:

applying the coating agent described in any one of claims 1 to 8 to a metal part of an electrical-electronic equipment to be subjected to exposure to a corrosive substance or moisture; and

curing the coating agent.

13. The method for protecting a metal part according to claim 12, wherein the metal part is formed by a metal selected from the group consisting of silver, copper, aluminum, and alloys of such metals.