JPH06116533A - Coating resin composition - Google Patents

Abstract

PURPOSE:To provide a coating resin composition causing no coating unevenness, excellent in wettability, slipperiness, releasability and lubricity, useful for construction facing, etc., comprising each specific silicone varnish and bifunctional cross-linking agent and a condensation reaction catalyst at specified proportion. CONSTITUTION:The composition comprising (A) 100 pts.wt. of a silicone varnish having in one molecule at least three silanol groups, (B) 0.1-50 pts.wt. of a bifunctional cross-linking agent of formula I or II (R<1> to R<3> are each monovalent hydrocarbon; Me is methyl; n is 0-4) and (C) 0.01-5 pts.wt. of a condensation reaction catalyst such as dibutyltin diacetate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for coating which is capable of imparting good releasing property and lubricity to the surface of a base material and obtaining a uniform coating film without unevenness.

[0002]

2. Description of the Related Art Conventionally, as a method for imparting releasability and lubricity to the surface of various base materials, silicone-based oils, fluorine-based oils or fluorinated oils excellent in releasability and lubricity have been used. A method of forming a coating film by adding a silicone resin to a coating agent and applying it to the surface of a substrate is known.

However, when a coating agent containing a silicone-based oil or a fluorine-based oil is applied to the surface of a base material, the oil content is lost with the lapse of time, so that the effectiveness as a release agent or a lubricant is lost. There is a problem that it ends up.

Further, the coating film formed by using a silicone resin does not have sufficient extensibility, and when used in a field requiring elongation, there is a problem in bending resistance and the like.

Therefore, JP-A-3-62855, 4-7.
In 6060 and the like, a method is proposed in which a diorganopolysiloxane having a hydroxyl group or an alkoxy group at the terminal of the molecular chain is used and a diorganopolysiloxane unit is introduced into the coating film by a reaction during curing.

[0006] However, since these coating agents contain an oil component, it is difficult to suppress uneven coating when applied to a base material, and the condensation reaction of the alkoxy groups is slow. It tends to remain on the surface and cause poor appearance.

The present invention has been made in view of the above circumstances,
To provide a resin composition for coating, which can impart good release properties and lubricity to a substrate, which does not easily deteriorate with time, and which has good wettability and can form a uniform coating film without coating unevenness. With the goal.

[0008]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above object, the present inventor has found that (A) 100 parts by weight of (B) a silicone varnish having 3 or more silanol groups in one molecule. ) When 0.1 to 50 parts by weight of a bifunctional crosslinking agent represented by the following formula (1) or (2) and 0.01 to 5 parts by weight of a (C) condensation reaction catalyst are added, preferably (D) is further added. When a trifunctional crosslinking agent represented by the following formula (3) or (4) is blended, that is, a bifunctional crosslinking agent is blended alone, or a trifunctional crosslinking agent is further used in combination with the resin composition for coating. When the product is applied to the surface of the base material, it can be evenly applied to the surface of the base material, and the coating film obtained by curing this has dimethylsiloxane units formed on the surface of the base material. Excellent in lubricity and lubricity, Property, lubricity is not deteriorated, adhesion to metals, rubber, plastics, etc. is good, and physical properties excellent in chemical resistance, moisture resistance, water repellency, weather resistance, etc. can be imparted. I found it. Furthermore, when the surface of the powdery substance is treated with this coating agent, the fluidity is improved, and therefore the coating resin composition is
It has been found that it can be suitably applied to building exteriors, surface modification of various organic rubbers, fluidity improver of inorganic powder such as iron, ferrite, magnesia, antifouling sheet agent of silicone sealing agent, etc. The present invention has been completed.

[0009]

[Chemical 3] (In the formulas (1) and (2), R ¹ , R ² , and R ³ are monovalent hydrocarbon groups, Me is a methyl group, and n is an integer of 0 to 4.)

[0010]

[Chemical 4] (In the formulas (3) and (4), R ⁴ , R ⁵ , R ⁶ and R ⁷ are 1
It is a valent hydrocarbon group. )

In this case, it can be confirmed by ESCA that a dimethylsiloxane unit is formed on the surface of the coating film by applying the composition of the present invention to the substrate and curing it. This is achieved by using the bifunctional cross-linking agents of 1) and (2), and even if the tri-functional cross-linking agents of the above formulas (3) and (4) are used alone, such a phenomenon is not observed. is there.

Therefore, according to the present invention, (A) 100 parts by weight of a silicone varnish having three or more silanol groups in one molecule, (B) a bifunctional crosslinking agent represented by the above formula (1) or (2) 1 to 50 parts by weight, (C) condensation reaction catalyst 0.0
1 to 5 parts by weight of the resin composition for coating, preferably (D) a trifunctional crosslinking agent represented by the above formula (3) or (4). A resin composition for coating is provided.

The present invention will be described in more detail below. The coating resin composition of the present invention comprises (A) a silicone varnish having 3 or more silanol groups in one molecule.
(B) a bifunctional crosslinking agent, (C) a condensation reaction catalyst, and preferably (D) a trifunctional crosslinking agent.

Here, the silicone varnish of the component (A) is not particularly limited as long as it has three or more silanol groups in one molecule, but the following general formula (5) is particularly preferable.
It is preferable to use the organopolysiloxane represented by

[0015]

[Chemical 5]

In the formula, R ⁸ is preferably a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms, specifically, an alkyl group such as a methyl group, an ethyl group or a propyl group, a phenyl group or the like. And the aryl group thereof. a is 0.8-1.
8, b is a positive number of 0.01 to 3, and a + b is 0.8 to
3.5, especially 0.8 to 2.5. This organopolysiloxane has R ⁹ SiO _3/2 units, R ¹⁰ SiO _3/2 units, R ¹¹ R ¹² SiO units (R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are R ⁸
Same monovalent hydrocarbon group), the number average molecular weight is preferably 1,000 to 50,000, and the OH group amount is 0.5 to 20% by weight, particularly 3 to 10% by weight. Preferably there is.

Such organopolysiloxane can be synthesized by using chlorosilane, alkoxysilanes and the like as raw materials.

Further, the block copolymerized organopolysiloxane obtained by hydrolyzing the silane represented by the following formula (6) alone or in combination with other silane is (A).
It can also be used as a component.

[0019]

[Chemical 6] (In the formula, X is an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, a trimethoxysilylethyl group, a chloro group, or the like. X is a positive number of 10 or more.)

The component (B) is a bifunctional crosslinking agent represented by the following formula (1) or (2), which can form a dimethylsiloxane unit when cured.

[0021]

[Chemical 7]

In the formula, R ^{1 to} R ³ are preferably substituted or unsubstituted monovalent hydrocarbon groups having 1 to 6 carbon atoms, specifically, alkyl groups such as methyl group, ethyl group and propyl group, Examples thereof include an aryl group such as a phenyl group. n is an integer of 0-4. When n exceeds 4, it becomes difficult to form dimethylsiloxane units on the surface of the coating film obtained from the resin composition of the present invention.

Specific examples of the component (B) include dimethyldi (methylketoxime) silane, dimethyldi (dimethylketoxime) silane, dimethyldi (isopropenyloxy) silane and dimethyldi (divinyloxy).
Examples include silane.

The blending amount of this component (B) is 10 parts of the component (A).
It is 0.1 to 50 parts with respect to 0 parts (parts by weight, the same applies hereinafter), but it is particularly preferably 0.5 to 20 parts. If the content is less than 0.1 part, the dimethylsiloxane unit cannot be formed on the surface, and if it exceeds 50 parts, the coating film becomes soft and the curability of the resin composition also deteriorates. Will end up.

As the catalyst for the condensation reaction of the component (C), an organic metal catalyst or an amino group-containing silane coupling agent used in ordinary silanol dehydration condensation can be used. As such an organometallic catalyst, specifically, tin,
Iron, manganese, cobalt, aluminum, zinc, zirconium, organometallic catalysts such as titanium, for example, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctoate,
Tin octylate, zinc naphthenate, cobalt octylate, iron octylate, zinc octylate, zirconium octylate, manganese octylate, dibutoxyacetoalkoxyaluminum, diisopropoxyacetoalkoxyaluminum, and the like, amino group-containing silane cup Examples of the ring agent include organic amine catalysts such as N- (β-aminoethyl) aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, tri (n-hexyl) amine, and diazabicycloundecene.

The amount of the catalyst blended is 0.001 to 5 parts with respect to 100 parts of the component (A), but it is particularly preferably 0.1 to 2 parts. If the blending amount is less than 0.001 part, the resin composition will not cure, and if it exceeds 5 parts, gelation, catalyst precipitation, etc. occur, causing a problem in storage stability.

The resin composition of the present invention is preferably further blended with a trifunctional crosslinking agent represented by the following formula (3) or (4) as the component (D). B)
It is effectively used when hardness and curability cannot be sufficiently obtained only by blending the components.

[0028]

[Chemical 8]

In the formula, R ^{4 to} R ⁷ are preferably substituted or unsubstituted monovalent hydrocarbon groups having 1 to 6 carbon atoms, specifically, alkyl groups such as methyl group, ethyl group and propyl group, Examples thereof include an aryl group such as a phenyl group. Specific examples of such a trifunctional crosslinking agent include methyltri (methylethylketoxime) silane, vinyltri (methylethylketoxime) silane, methyltri (dimethylketoxime) silane, vinyltri (dimethylketoxime) silane, and methyltri (isopropenyloxy) silane. , Vinyltri (isopropenoxy) silane, phenyltri (isopropenoxy) silane and the like.

The blending amount of the component (D) is preferably 0 to 50 parts, especially 5 to 40 parts, relative to 100 parts of the component (A). If this blending amount exceeds 50 parts, the coating film may become brittle and lose flexibility.

The composition of the present invention is preferably used by diluting it with an organic solvent from the viewpoint of coating efficiency. Examples of such an organic solvent include aromatic hydrocarbons such as toluene, xylene and benzene, alcohols such as methanol, ethanol and isopropyl alcohol, n-hexane and n-.
Heptane, octane, ligroin, aliphatic hydrocarbons such as industrial gasoline, trichlorethylene, carbon tetrachloride,
Examples thereof include chlorinated solvents such as 1,1,1-trichloroethane and perchloroethylene, and ketone-based organic solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone. Of these, toluene and xylene, which have high solubility in organopolysiloxane, are particularly preferable. In addition,
The amount of the organic solvent used may be any amount.

A silane coupling agent may be added to the composition of the present invention for the purpose of improving the adhesion to metal, rubber and the like. Examples of the silane coupling agent include those represented by the following formula. In addition, these may be used individually or in mixture of 2 or more types.

[0033]

[Chemical 9]

The addition amount of the silane coupling agent is preferably 0.01 to 10 parts with respect to 100 parts of the component (A).

Further, the composition of the present invention contains inorganic fine powder such as talc, silica, silicon nitride powder or organic fine powder such as silicone resin fine powder and polyethylene fine powder for the purpose of improving releasability and lubricity. Powders can be included.
In this case, the compounding amount is 0.0 with respect to 100 parts of the component (A).
It is preferably 1 to 10 parts.

It is also possible to add colorants such as dyes and pigments within the range that does not impair the object of the present invention.

A conventional method can be employed to cure the composition of the present invention. For example, the composition of the present invention may be left at room temperature for 1 to 7 days to be cured by moisture in the air.
It is also possible to employ a method of heat curing by heating to about 80 to 150 ° C.

[0038]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. Prior to the description of each example, a production example of the organopolysiloxane compounded in the composition of the present invention will be described.

[Production Example] CH ₃ Si (OCH ₃ ) ₃ 109
Parts, 14.8 parts of siloxane represented by the following formula (7) and 74.9 parts of toluene are mixed, then 3.4 parts of methanesulfonic acid and 25.9 parts of water are added dropwise, and the mixture is added at 50 ° C. for 5 hours. The mixture was aged, and neutralized by adding 4.7 parts of sodium hydrogen carbonate. Then distill off the methanol, dilute with toluene,
A 40% non-volatile content organopolysiloxane toluene solution (hereinafter referred to as a resin A solution) was produced. The viscosity of the resin A solution at 25 ° C. is 10 centistokes (c
s). The obtained resin A is as follows.

[0040]

[Chemical 10]

[Example 1] 100 parts of resin A solution, 100 parts of rubber volatile oil, 12 parts of bifunctional crosslinking agent represented by the following formula (8), and silane coupling agent represented by the following formula (9) 0 0.8 parts of dibutyltin dioctate was mixed and flow-coated on a mild steel plate having a thickness of 0.3 mm, which was air-dried for 5 minutes and then heat-cured at 150 ° C. for 30 minutes to obtain a thickness of 5 μm. A coating film was obtained.

[0042]

[Chemical 11]

The following physical properties tests were conducted on the obtained coating film. The results are shown in Table 1.

Adhesion: According to JIS-K5400, items 6 to 15, the coating film was cut with a knife at 1 mm intervals in lengths and widths of 11 each to form 100 squares, and adhesive cellophane tape (cellophane tape, Nichiban) was formed. A peel test was carried out by adhering and peeling (commercial product) to this mesh, and the number of meshes remaining after peeling was evaluated. Flex resistance: According to JIS-K5400, items 6 to 16, a mandless test (distance: 2 mm) was performed, and the following criteria were evaluated. ◯: No abnormal appearance ×: Abnormal appearance Water repellency: Shown by water contact angle. Lubricity: The coefficient of dynamic friction is shown.

[Embodiment 2] In Embodiment 1, the equation (8) is used.
A coating film was obtained in the same manner as in Example 1 except that the bifunctional crosslinking agent represented by the following formula (10) was used in place of the bifunctional crosslinking agent represented by, and the same physical property test was performed. The results are also shown in Table 1.

[0046]

[Chemical 12]

Example 3 In Example 1, the compounding amount of the bifunctional crosslinking agent represented by the formula (8) was 8 parts, and the following formula (1)
A coating film was obtained in the same manner as in Example 1 except that 12 parts of the trifunctional crosslinking agent represented by 1) was added, and the same physical property test was performed. The results are also shown in Table 1.

[0048]

[Chemical 13]

Example 4 In Example 1, the compounding amount of the bifunctional crosslinking agent represented by the formula (8) was 2 parts, and the above formula (1) was used.
A coating film was obtained in the same manner as in Example 1 except that 12 parts of the trifunctional crosslinking agent represented by 1) was added, and the same physical property test was performed. The results are also shown in Table 1.

[Example 5] The same as Example 1 except that a bifunctional crosslinking agent represented by the following formula (12) was used in place of the bifunctional crosslinking agent represented by the formula (8) in Example 1. Then, a coating film was obtained, and the same physical property test was performed. The results are also shown in Table 1.

[0051]

[Chemical 14]

Comparative Example 1 Instead of the bifunctional crosslinking agent represented by the formula (8) in Example 1, a trifunctional crosslinking agent represented by the formula (11) similar to that used in Example 3 was used. A coating film was obtained in the same manner as in Example 1 except that it was used, and the same physical property tests were performed. The results are also shown in Table 1.

[Comparative Example 2] The amount of the bifunctional crosslinking agent represented by the formula (8) in Example 1 was set to 60 parts, and Example 3 was used.
A coating film was obtained in the same manner as in Example 1 except that 12 parts of the trifunctional crosslinking agent represented by the formula (11) similar to that used in Example 1 was added, but this film was brittle. Further, the same physical property test as in Example 1 was conducted on this coating film. The results are also shown in Table 1.

[Comparative Example 3] A composition obtained in the same manner as in Example 1 except that dibutyltin octoate was not used was cured. As a result, the composition was cured under curing conditions of 150 ° C / 30 minutes. , It did not cure in air. Further, the same physical property test as in Example 1 was performed. The results are also shown in Table 1.

Comparative Example 4 A cured product was obtained in the same manner as in Example 1 except that the compounding amount of dibutyltin octoate was changed to 6 parts in Example 1 and gelled after 2 days with a stopper.
Further, the same physical property test as in Example 1 was performed. The results are shown in Table 1.
Also described in.

[0056]

[Table 1]

The ESCA analysis of the coating films obtained in Example 1 and Comparative Example 1 was carried out. The results are shown in Table 2.

[0058]

[Table 2]

From the results in Table 2, it can be seen that the composition ratio on the surface of the coating film in Example 1 was Si: O: C = 1: 1: 2, and dimethylsiloxane units were present on the surface of the coating film. .

[0060]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain a uniform coating film having good wettability and no coating unevenness, and to provide a substrate with good mold releasability and lubricity that does not easily deteriorate with time. It is possible to obtain a coating resin composition capable of

Claims (2)

[Claims] 1. (A) 100 parts by weight of a silicone varnish having three or more silanol groups in one molecule, (B) a bifunctional cross-linking agent represented by the following formula (1) or (2): 0.1 to 50. Parts by weight, (In the formulas (1) and (2), R ¹ , R ² , and R ³ are monovalent hydrocarbon groups, Me is a methyl group, and n is an integer of 0 to 4.) (C) Condensation reaction catalyst 0 0.01 to 5 parts by weight of the resin composition for coating. 2. The composition according to claim 1, further comprising (D) a trifunctional crosslinking agent represented by the following formula (3) or (4). Coating resin composition. [Chemical 2] (In the formulas (3) and (4), R ⁴ , R ⁵ , R ⁶ and R ⁷ are 1
It is a valent hydrocarbon group. )