JPH08151553A - Silicone coating agent - Google Patents

Abstract

PURPOSE: To obtain the subject coating agent comprising a specific organopolysiloxane and a specific dialkylpolysiloxane, and giving cured coating films excellent in the adhesivity of an ink, etc., and easy in their wipe. CONSTITUTION: This coating agent comprises (A) 100 pts.wt. of an organopolysiloxane comprising 5-70mol.% of units of formula: C6 H5 SiO3/2 , 5-40mol.% of units of formula: CH3 SiO3/2 , and 5-80mol.% of units of formula: R<1> 2 SiO2/3 (R<1> is monovalent hydrocarbon), and containing 0.05-50wt.% of silanol groups and/or Si atom-bound alkoxy groups, and (B) 0.001-10 pts.wt. of a dialkylpolysiloxane of the formula (R<2> is alkyl; R<3> is alkyl; a is 1, 2; n is 2-100) or its partial hydrolytic condensate. The coating agent is preferably further compounded with (C) 0.01-100 pts.wt. of a silane compound of formula: R<4> SiX(4-b) (R<4> is monovalent hydrocarbon; X is hydrolyzable group; b is 0, 1) or its partial hydrolytic condensate) and/or (D) 0.001-10 pts.wt. of a condensation catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicone-based coating agent, and more particularly, to a silicone-based coating agent that forms a cured film that has excellent adhesion to inks and paints and that can be easily wiped off.

[0002]

2. Description of the Related Art Silicone coating agents are applied to various substrates and then left at room temperature, or
Water repellency, oil repellency, and
A cured film having excellent antifouling property, heat resistance, weather resistance and chemical resistance can be formed. Therefore, this silicone coating agent is used as a coating agent for preventing adhesion of snow, ice, etc., an antifouling coating agent, and a peeling or releasing coating agent. Examples of such silicone-based coating agents include resinous organopolysiloxanes having silanol groups, diorganopolysiloxanes capped with silanol groups at both molecular chain terminals, and silane compounds containing hydrolyzable groups or partial hydrolysis thereof. Silicone-based coating agent consisting of
No. 48245), an organopolysiloxane containing a silicon atom-bonded alkoxy group, a silanol group-containing organopolysiloxane, an organosilicon compound having an amino group, an imino group or a nitrilo group, and an alkoxy group, and a silicone system comprising a condensation reaction catalyst. Coating agent (see JP-A-60-49066), C ₆ H ₅ SiO
_3/2 units, CH ₃ SiO _3/2 units, (C ₆ H ₅ ) ₂ SiO _2/2 units and C ₆ H ₅ (CH ₃ ) SiO _{2/2 with} a silanol group content of 0.5. ~ 5 wt%, the ratio of organic groups to silicon atoms is 0.8 to 1.4, the ratio of phenyl groups to silicon atoms is 0.35 to 0.85, methyltrimethoxysilane A silicone-based coating agent (see JP-A-60-118761) is proposed, which comprises a silanol group-capped dimethylpolysiloxae at both ends of the molecular chain and a condensation reaction catalyst.

[0003]

However, even if the cured film formed by these coating agents has poor adhesion of ink or paint, or even if they have excellent adhesion, they are very easily wiped off. There was a problem that it was difficult. The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, an object of the present invention is to provide a silicone-based coating agent that forms a cured film that has excellent adhesion to inks and paints and that can be easily wiped off.

[0004]

MEANS FOR SOLVING THE PROBLEM AND ACTION THEREOF The present invention provides (A) C ₆ H ₅ SiO _3/2 units of ₅ to 70 mol%, CH ₃ S
iO (wherein, R ¹ is identical or different monovalent hydrocarbon group.) _3/2 40 mol% and R ¹ ₂ SiO _2/2 units consist 5-80 mol%, a silanol group and /
Alternatively, 100 parts by weight of organopolysiloxane containing 0.05 to 50% by weight of a silicon atom-bonded alkoxy group and (B) the general formula:

Embedded image (In the formula, R ² is the same or different alkyl group, R ³
Are the same or different alkyl groups, and a is 1 or 2
And n is a number from 2 to 100. The present invention relates to a silicone coating agent comprising 0.001 to 10 parts by weight of a dialkyl polysiloxane represented by the formula (1) or a partial hydrolysis-condensation product thereof.

The present invention also provides (A) C ₆ H ₅ SiO _3/2 units of ₅ to 70 mol% and CH ₃ SiO _3/2 units of 5 to 40 mol%.
And R ¹ ₂ SiO _2/2 units (wherein, R ¹ is identical or different monovalent hydrocarbon group.) A 5 to 80 mol%,
100 parts by weight of organopolysiloxane containing 0.05 to 50% by weight of silanol groups and / or silicon atom-bonded alkoxy groups, (B) general formula:

[Chemical 4] (In the formula, R ² is the same or different alkyl group, R ³
Are the same or different alkyl groups, and a is 1 or 2
And n is a number from 2 to 100. 0.001 to 10 parts by weight of a dialkyl polysiloxane represented by the formula) or a partial hydrolysis-condensation product thereof, (C) General formula: R ⁴ _b SiX _(4-b) (wherein R ⁴ is a monovalent hydrocarbon group) And X is a hydrolyzable group, and b is 0 or 1.) The silane compound or its partial hydrolyzed condensate 0.01 to 10
0 parts by weight and / or (D) catalyst for condensation reaction
The present invention relates to a silicone coating agent composed of 0.001 to 10 parts by weight.

The silicone coating agent of the present invention will be described in detail below. The organopolysiloxane of the component (A) is a main component of the composition consists of C ₆ H ₅ SiO _3/2 units, CH ₃ SiO _3/2 units and R ¹ ₂ SiO _2/2 units. In the formula, R ¹ is the same or different monovalent hydrocarbon group, and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group; vinyl group, allyl group, butenyl group, Alkenyl groups such as pentenyl group and hexenyl group; aryl groups such as phenyl group, tolyl group and xylyl group; aralkyl groups such as benzyl group, phenethyl group and phenylpropyl group, and preferably methyl group, vinyl group and phenyl group. It is a base. In the component (A), the C ₆ H ₅ SiO _3/2 unit is a unit for improving the film-forming property of the present composition, and the content thereof is 5 to 70 mol%, particularly 10 It is preferably 50 mol%. Further, the CH ₃ SiO _3/2 unit is a unit for improving the film hardness of the present composition, and the content thereof is 5 to 5.
It is 40 mol%, and particularly preferably 10 to 40 mol%. Further, R ¹ ₂ SiO _2/2 units is a unit for film-forming and improving the flexibility of the coating of the present composition, the content thereof is 5 to 80 mol%, in particular, 10 It is preferably ˜80 mol%. R ¹ ₂ Si
Examples of the O _2/2 unit include (CH ₃ ) ₂ SiO _2/2 unit, (C ₆ H ₅ ) ₂ SiO _2/2 unit, (CH ₃ ) (C ₆ H ₅ )
An example is a SiO _2/2 unit. In addition, the component (A) has a silanol group and / or a silicon atom-bonded alkoxy group, and the content thereof is 0.05 to 50% by weight.
The silanol group content is preferably 0.05 to 10% by weight.

The component (B), a dialkyl polysiloxane or a partial hydrolyzed condensate thereof, does not impair the adhesion of the ink and penint of the cured film formed by the present composition and facilitates the wiping of them. The dialkyl polysiloxane as the component (B) is an additive for the above formula. In the formula, R ² is the same or different alkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group and a hexyl group, and preferably a methyl group. Further, R ³ in the formula is the same or different alkyl group, and the same groups as R ² are exemplified, and preferably a methyl group and an ethyl group. In addition, a in the formula is 1 or 2. Further, n in the formula is 2 to 10
It is a number of 0, and a number of 5 to 50 is particularly preferable. The method for preparing the component (B) is not particularly limited, and examples thereof include a method in which a dimethylpolysiloxane having silanol groups at both terminals of the molecular chain and phenyltrimethoxysilane or diphenyldimethoxysilane are subjected to a condensation reaction. In order to accelerate this condensation reaction, it is preferable to use a basic catalyst such as potassium hydroxide, sodium hydroxide or barium hydroxide.

The blending amount of the component (B) is in the range of 0.001 to 10 parts by weight, particularly 0.05 to 5 parts by weight, relative to 100 parts by weight of the component (A). Is preferred. This is because if the blending amount of the component (B) is less than 0.001 part by weight relative to 100 parts by weight of the component (A), it will be very difficult to wipe off the ink and paint attached to the cured film. If the amount exceeds 10 parts by weight, the component (B) bleeds out from the cured coating, or the adhesion of ink or paint to the cured coating is significantly impaired.

The composition is prepared by uniformly mixing the above-mentioned components (A) and (B). Since it is difficult for this composition to form a cured film at room temperature,
After applying this to the substrate, it is necessary to heat it to 200 to 250 ° C. In order to form the cured coating by heating the composition to room temperature or a temperature of 250 ° C. or lower, the composition is further subjected to a condensation reaction of the silane compound of the component (C) and / or the component (D). It is preferable to add a catalyst for use. When a highly reactive silane compound such as vinyltrioxime silane is used as the component (C), the component (D) is not always necessary. When a highly reactive organopolysiloxane is used as the component (A),
The component (C) is not always necessary. However, the composition may be heated at room temperature or below 200 ° C. for 30 minutes to 24 hours.
In order to cure in time, it is preferable to use the component (C) and the component (D) together.

The silane compound as the component (C) or a partial hydrolyzate thereof acts as a crosslinking agent of the present composition and is represented by the above general formula. In the formula, R ⁴ is a monovalent hydrocarbon group, and examples thereof include the same groups as R ¹ . Further, X in the formula is a hydrolyzable group, for example, a methoxy group, an ethoxy group,
Alkoxy groups such as propoxy group, butoxy group, methoxyethoxy group, alkenyloxy groups such as isopropenyloxy group, 2-ethylhexanoxy group, 1-ethyl-2-methylvinyloxy group, acetoxy group, dimethylketoxime group. , A methylethylketoxime group, a ketoxime group such as a diethylketoxime group, a setoxy group, an octanoyloxy group, an acyloxy group such as a benzoyloxy group,
Amino groups such as dimethylamino group, diethylamino group, butylamino group and cyclohexylamino group, aminoxy groups such as dimethylaminoxy group and diethylaminoxy group,
Examples thereof include amide groups such as N-methylacetamide group, N-ethylacetamide group and N-methylbenzamide group. Further, b in the formula is 0 or 1.

Examples of the component (C) include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, methyltris (methoxyethoxy) silane, Alkoxysilane compounds such as vinyltris (methoxyethoxy) silane; tetra (isopropenoxy) silane, methyltris (isopropenoxy) silane, alkenoxysilane compounds such as vinyltris (isopropenoxy) silane; tetra (acetoxy) silane, methyltriacetoxysilane, vinyltri Acetoxysilane compounds such as acetoxysilane; tetra (acetoneoxime) silane, methyltris (acetoneoxime) silane, vinyltris (acetoneoxime) silane Oxime silane compounds such as methyltris (butanoneoxime) silane, methyltris (cyclohexanoneoxime) silane, methyltris (dimethylketoxime) silane, vinyltris (dimethylketoxime) silane, methyltris (methylethylketoxime) silane, vinyltris (methylethylketoxime) silane; methyltris (N-methylacetamide)
Silane, vinyltris (N-methylacetamide) silane, methyltris (N-ethylacetamide) silane,
Amidosilane compounds such as vinyltris (N-ethylacetamido) silane; methyltris (N, N-dimethylaminoxy) silane, vinyltris (N, N-dimethylaminoxy) silane, methyltris (N, N-diethylaminoxy) silane, methyltris ( Examples include aminosilane compounds such as cyclohexylamino) silane, and partially hydrolyzed condensates of these organosilanes.
As the component (C), one kind or a mixture of two or more kinds of these silane compounds or their partial hydrolysis-condensation products can be used.

The blending amount of the component (C) is preferably in the range of 0.01 to 100 parts by weight, and particularly in the range of 5 to 50 parts by weight, relative to 100 parts by weight of the component (A). It is preferable. This is because the blending amount of the (C) component is the (A) component 1
This is because if it is less than 0.01 parts by weight relative to 00 parts by weight, it will be difficult for the resulting coating agent to be sufficiently cured in 30 minutes to 24 hours by heating at room temperature or 200 ° C. or less. This is because if the amount exceeds 100 parts by weight, the mechanical properties of the cured film obtained will be significantly reduced.

The condensation reaction catalyst of the component (D) is a component that accelerates the curing of the composition when heated at room temperature or 200 ° C. or lower. Examples of the component (D) include iron octoate, cobalt octoate, manganese octoate, tin octoate, lead octoate, zinc octoate, iron naphthenate, cobalt naphthenate, tin naphthenate, lead naphthenate, capryl. Tin acid, tin oleate, tin linoleate, tin isobutyrate, tin stearate, tin benzoate, tin naphthoate, tin laurate, tin o-timate, tin β-benzoylpropionate, tin crotonic acid, trobaric acid Metal salts of organic acids such as tin, tin p-bromobenzoate, tin palmitooleate, tin cinnamate and tin phenylacetate; dibutyltin diacetate,
Dibutyltin dilaurate, dibutyltin dioctoate,
Organotin compounds such as dimethyltin dimonooleate, dioctyltin dilaurate, diphenyltin diacetate, dibutyltin oxide, dimethyltin dimethoxide and dibutyltin dimethoxide; metal alcoholates such as tetraisopropyl titanate, tetrabutyl titanate and tetrabutyl zirconate; diiso Propoxybis (acetylacetonate) titanium, diisopropoxybis (ethylacetoacetate) titanium, 1,3-propanedioxybis (acetylacetonate) titanium, 1,3-propanedioxybis (ethylacetoacetate) titanium, etc. Titanium chelate of.

The blending amount of the component (D) is preferably 0.001 to 10 parts by weight with respect to 100 parts by weight of the component (A). This is because the amount of component (D) is 1
This is because if it is less than 0.001 part by weight with respect to 00 parts by weight, it will be difficult to sufficiently cure the obtained coating agent in 30 minutes to 24 hours by heating at room temperature or 200 ° C. or less. This is because if the amount exceeds 10 parts by weight, the mechanical properties of the obtained cured coating deteriorate.

The composition of the present invention may also include other optional components such as fumed silica, precipitated silica, pyrogenic silica, titanium dioxide, carbon black, alumina,
Quartz powder, calcium carbonate, diatomaceous earth, aluminosilicate, magnesia, and inorganic fillers obtained by surface-treating these inorganic fillers with organosilicon compounds such as organoalkoxysilanes, organochlorosilanes and organosilazanes; diethyl ether, Ether solvents such as dipropyl ether, tetrahydrofuran and ethylene glycol diethyl ether, ester solvents such as ethyl acetate, butyl acetate and amyl acetate, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and acetophenone, methanol, ethanol and isopropanol. , Butanol, 2-methoxyethanol, 2
Alcoholic solvents such as ethoxyethanol, ethylene glycol, propylene glycol, hexamethyldisiloxane, tetramethyldiphenyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, heptamethyl Siloxane compounds such as phenylcyclotetrasiloxane, heptamethylvinylcyclotrisiloxane and decamethylcyclopentasiloxane, organics such as hexane, heptane, octane, cyclohexane, toluene, xylene, naphtha, mineral split, petroleum benzine and other hydrocarbon solvents solvent;
3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-N- (2-aminoethyl) aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane A silane coupling agent such as

The silicone coating agent of the present invention is
After applying this to the substrate, leave it at room temperature or 250 ℃
A cured coating can be formed by heating below, and the cured coating has water repellency, oil repellency, antifouling property, heat resistance,
Since it has excellent weather resistance and chemical resistance, this coating agent can be used as, for example, a coating agent for preventing adhesion of water drops, snow, ice, etc., an antifouling coating agent, and a peeling or releasing coating agent.

[0017]

EXAMPLES The silicone coating agent of the present invention will be described in detail with reference to Examples. The viscosity in the examples is 25.
It is a value measured at ° C.

[Reference Example 1] A 500 ml-four-necked flask equipped with a stirrer, a cooling tube, and a thermometer had a viscosity of 40 centistokes and an average formula:

Embedded image 200 g of dimethylpolysiloxane capped with silanol groups at both ends of the molecular chain represented by: phenyltrimethoxysilane 20
0 g and 0.1 g of barium hydroxide were added, and the system was heated with stirring at 75 ° C. for 2 hours. Then, after cooling the system, 0.1 g of acetic acid was added. The salt formed was filtered, and the filtrate was heated under the conditions of 150 ° C. and 20 mmHg to give an average formula:

[Chemical 6] A dimethylpolysiloxane capped with dimethoxyphenylsiloxy groups at both ends of the molecular chain represented by was synthesized.

Reference Example 2 In Reference Example 1, the viscosity is 4
An average formula having a viscosity of 120 centistokes instead of a dimethylpolysiloxane having silanol groups at both ends of the molecular chain, which is 0 centistokes:

[Chemical 7] In the same manner as in Reference Example 1 except that a dimethylpolysiloxane having silanol groups at both ends of the molecular chain represented by

Embedded image A dimethylpolysiloxane capped with dimethoxyphenylsiloxy groups at both ends of the molecular chain represented by was synthesized.

[Reference Example 3] In a 500 ml-four-necked flask equipped with a stirrer, a cooling tube, and a thermometer, 200 g of dimethylpolysiloxane capped with dimethoxyphenylsiloxy groups at both ends of the molecular chain synthesized in Reference Example 1, and 2 g of acetic acid. , 20 g of methanol and 4 g of pure water were added, and the mixture was heated with stirring at the methanol reflux temperature for 1 hour. This system is then replaced with 20
Under reduced pressure of mmHg, heat and stir at 150 ℃, the viscosity becomes 2
A partially hydrolyzed condensate of dimethylpolysiloxane having 50 centistokes was synthesized.

Reference Example 4 A 500 ml-four-necked flask equipped with a stirrer, a cooling tube and a thermometer had a viscosity of 120 centistokes and an average formula:

[Chemical 9] 200 g of dimethylpolysiloxane with silanol groups blocked at both ends of the molecular chain represented by the formula: diphenyldimethoxysilane 20
0 g and 0.1 g of barium hydroxide were added, and the system was heated with stirring at 75 ° C. for 2 hours. Then, after cooling the system, 0.1 g of acetic acid was added. The salt formed was filtered, and the filtrate was heated under the conditions of 150 ° C. and 20 mmHg to give an average formula:

[Chemical 10] A dimethylpolysiloxane capped with methoxydiphenylsiloxy groups at both ends of the molecular chain represented by was synthesized. Next, 200 g of this dimethylpolysiloxane was added to a stirrer, a cooling pipe,
It was put into a 500 ml-four-necked flask equipped with a thermometer, 2 g of acetic acid, 20 g of methanol and 4 g of pure water were put into this system, and the mixture was heated and stirred at a methanol reflux temperature for 1 hour. Then, the system is put under a reduced pressure of 20 mmHg for 1
Heat and stir at 50 ° C., average formula:

[Chemical 11] A partially hydrolyzed condensate of dimethylpolysiloxane represented by

[Example 1] C ₆ H ₅ SiO _3/2 unit 15 mol%, CH ₃ SiO _3/2 unit 25 mol%, (C ₆ H ₅ ) ₂ Si
100 parts by weight of organopolysiloxane consisting of 10 mol% of O _2/2 unit and 50 mol% of C ₆ H ₅ (CH ₃ ) SiO _2/2 unit (silanol group content = 3 wt%), methyltris (methylethylketoxime) 30 parts by weight of silane, 0.5 parts by weight of dimethylpolysiloxane blocked with dimethoxyphenylsiloxy groups at both ends of the molecular chain synthesized in Reference Example 1, 2 parts by weight of dibutyltin diacetate and 50 parts by weight of toluene are uniformly mixed to obtain a silicone coating. The agent was prepared. After coating this coating agent on an aluminum test panel, it was placed in a hot air circulation oven at 150 ° C for 1 hour.
Heated for hours. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. afterwards,
When the letters were wiped with a dry cloth, the letters could be completely wiped off.

Example 2 C ₆ H ₅ SiO _3/2 units 40 mol%, CH ₃ SiO _2/2 units 30 mol% and (CH ₃ ) ₂ S
100 parts by weight of organopolysiloxane consisting of 30 mol% of iO _2/2 (silanol group content = 1% by weight),
30 parts by weight of methyltrimethoxysilane, 0.1 parts by weight of dimethylpolysiloxane blocked with dimethoxyphenylsiloxy groups at both ends of the molecular chain synthesized in Reference Example 2 and 2 parts by weight of dibutyltin diacetate were uniformly mixed to obtain a silicone-based coating agent. Prepared. After applying this coating agent on an aluminum test panel, it was heated in a hot air circulation type oven at 150 ° C. for 1 hour. A commercially available lacquer spray (manufactured by Nippon Paint Co., Ltd .; trade name: Nippe Home Paint) was applied to the surface of the cured coating formed on the test panel. No repellency of the paint occurred. After standing for 24 hours, the cured coating film was wiped with a dry cloth, and the cured coating film was peeled off in a film form.

Example 3 C ₆ H ₅ SiO _3/2 unit 15 mol%, CH ₃ SiO _3/2 unit 25 mol%, (C ₆ H ₅ ) ₂ Si
100 parts by weight of organopolysiloxane consisting of 10 mol% of O _2/2 unit and 50 mol% of C ₆ H ₅ (CH ₃ ) SiO _2/2 unit (content of silanol group = 3 wt%), methyltrimethoxysilane 30 By weight, 1.0 part by weight of the partially hydrolyzed condensate of dimethylpolysiloxane synthesized in Reference Example 3 and 2 parts by weight of dibutyltin diacetate were uniformly mixed to prepare a silicone-based coating agent. After applying this coating agent on an aluminum test panel,
It heated at 150 degreeC in the hot-air circulation type oven for 1 hour. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. After that, when the letters were wiped with a dry cloth, the letters could be completely wiped off.

Example 4 40 mol% of C ₆ H ₅ SiO _3/2 units, 30 mol% of CH ₃ SiO _2/2 units and (CH ₃ ) ₂ S
100 parts by weight of organopolysiloxane composed of 30 mol% of iO _2/2 unit (content of silanol group = 1% by weight) and 0.05 part by weight of dimethylpolysiloxane blocked with dimethoxyphenylsiloxy groups at both molecular chain ends synthesized in Reference Example 2 The parts were uniformly mixed to prepare a silicone-based coating agent. After applying this coating agent on an aluminum test panel, it was heated in a hot air circulation oven at 250 ° C. for 1 hour. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. After that, when the letters were wiped with a dry cloth, the letters could be completely wiped off.

[Embodiment 5] Referential Example 1 in Embodiment 1
A silicone-based coating agent was prepared in the same manner as in Example 1 except that the partially hydrolyzed condensate of dimethylpolysiloxane synthesized in Reference Example 4 was used in place of the dimethylpolysiloxane capped with dimethoxyphenylsiloxy groups at both ends of the molecular chain synthesized in 1. Was prepared. After applying this coating agent on an aluminum test panel, it was heated in a hot air circulation type oven at 150 ° C. for 1 hour. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. After that, when the letters were wiped with a dry cloth, the letters could be completely wiped off.

[Comparative Example 1] Referential Example 1 in Example 1
A silicone-based coating agent was prepared in the same manner as in Example 1 except that the dimethylpolysiloxane having dimethoxyphenylsiloxy groups blocked at both ends of the molecular chain synthesized in 1. was not added. After coating this coating agent on an aluminum test panel, it was placed in a hot air circulation oven at 150 ° C for 1 hour.
Heated for hours. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. afterwards,
I wiped this letter with a dry cloth, but I couldn't completely wipe it off.

[Comparative Example 2] Reference Example 2 in Example 2
A silicone-based coating agent was prepared in the same manner as in Example 2 except that the dimethylpolysiloxane having dimethoxyphenylsiloxy groups blocked at both ends of the molecular chain synthesized in 1. was not added. After coating this coating agent on an aluminum test panel, it was placed in a hot air circulation oven at 150 ° C for 1 hour.
Heated for hours. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink. No ink repellency or blurring of characters occurred. afterwards,
I wiped this letter with a dry cloth, but I couldn't completely wipe it off.

[Comparative Example 3] Reference Example 1 in Example 1
In place of the dimethylpolysiloxane capped with dimethoxyphenylsiloxy groups at both ends of the molecular chain synthesized in 1., the viscosity is 80 centistokes, and the average formula:

[Chemical 12] A silicone-based coating agent was prepared in the same manner as in Example 1 except that 1.0 part by weight of dimethylpolysiloxane having silanol groups at both ends of the molecular chain represented by the above formula was added. This coating agent was cloudy. After applying this coating agent on an aluminum test panel,
The mixture was heated in a hot air circulation oven at ℃ for 1 hour. Characters were written on the surface of the cured film formed on the test panel with a commercially available oil-based ink, but the ink was repelled and the characters were faded.

[0030]

The silicone-based coating agent of the present invention is characterized in that it has excellent adhesion to inks and paints and can form a cured film that can be easily wiped off.

Claims (2)

[Claims] 1. A _{(A) C 6 H 5 SiO} 3/2 units 5 to 70 mol%, CH ₃ SiO _3/2 units 40 mol% and R ¹ ₂ Si
O _2/2 unit (in the formula, R ¹ is the same or different monovalent hydrocarbon group) 5 to 80 mol%, and a silanol group and / or a silicon atom-bonded alkoxy group is contained in an amount of 0.05 to
100 parts by weight of organopolysiloxane containing 50% by weight and (B) the general formula: (In the formula, R ² is the same or different alkyl group, R ³
Are the same or different alkyl groups, and a is 1 or 2
And n is a number from 2 to 100. ) A silicone coating agent comprising 0.001 to 10 parts by weight of a dialkyl polysiloxane represented by the formula (1) or a partial hydrolysis-condensation product thereof. Wherein _{(A) C 6 H 5 SiO} 3/2 units 5 to 70 mol%, CH ₃ SiO _3/2 units 40 mol% and R ¹ ₂ Si
O _2/2 unit (in the formula, R ¹ is the same or different monovalent hydrocarbon group.) 5 to 80 mol%, and a silanol group and / or a silicon atom-bonded alkoxy group is contained in an amount of 0.05 to
100 parts by weight of organopolysiloxane containing 50% by weight, (B) general formula: (In the formula, R ² is the same or different alkyl group, R ³
Are the same or different alkyl groups, and a is 1 or 2
And n is a number from 2 to 100. 0.001 to 10 parts by weight of a dialkyl polysiloxane represented by the formula (1) or a partial hydrolysis-condensation product thereof, (C) General formula: R ⁴ _b SiX _(4-b) (In the formula, R ⁴ is a monovalent hydrocarbon group. And X is a hydrolyzable group, and b is 0 or 1.) A silane compound represented by the formula (1) or a partially hydrolyzed condensate thereof 0.01 to 10
0 parts by weight and / or (D) catalyst for condensation reaction
A silicone-based coating agent comprising 0.001 to 10 parts by weight.