JP3193600B2 - Coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition for forming a coating film having excellent scratch resistance, abrasion resistance and surface appearance with high adhesion on the surface of a molded product such as plastic or metal. About.

[0002]

2. Description of the Related Art Plastic molded products and metal molded products such as aluminum and zinc generally have disadvantages such as being easily damaged and easily worn due to low surface hardness. For the purpose of improving these problems, a coating film of a curable substance is formed on the surface of the molded product, and various coating compositions have been proposed for forming the coating film.

[0003] The coating composition generally comprises a hydrolyzable organosilicon compound to which an inorganic acid such as hydrochloric acid or sulfuric acid or an organic acid such as acetic acid is added and hydrolyzed, and a curing catalyst.

[0004] Various proposals have been made for the coating composition. Particularly, as for a curing catalyst, an acetylacetonate complex such as aluminum acetylacetonate is disclosed in Japanese Patent Application Laid-Open No. Hei 2-279778. Aluminum perchlorate
No. 9266 and Japanese Patent Application Laid-Open No. 2-189380.

[0005]

However, the viscosity of the above coating composition increases due to long-term storage,
Further, there is a problem that the properties of the coated film formed using the coating composition having increased viscosity are reduced. The conventional coating composition has a period in which the physical properties of the obtained coat film do not decrease, that is, a pot life is several days to 20 days.
It was as short as days. For this reason, there has been a problem of uneconomical effect that the coating composition must be disposed of before it is used up. Accordingly, it is desired that the coating composition has a longer working life.

[0006] Regarding the extension of the pot life, a method of adjusting the pH of the coating composition is disclosed in JP-A-56-88461.
No. 1993. However, the conventionally proposed method of using an inorganic / organic acid / alkali or a metal salt thereof as a pH adjuster causes local cloudiness or gelation when the pH adjuster is added to the coating solution. , Impairs the performance of the coating liquid. Also, there is a problem that it is difficult to finely adjust the pH and the workability is extremely poor.

As described above, there is no example in which the usable life can be extended without deteriorating the characteristics desired for the coat film.

[0008]

Means for Solving the Problems According to the present invention, as a result of intensive studies to solve such problems, a coating composition which can extend the usable life without impairing the performance of the coating film at all was found. The present invention has been completed.

That is, the present invention relates to (a) the general formula (1)

[0010]

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(However, A means that the main chain is at least linearly
A divalent hydrocarbon group of 4 or more atoms, R ¹
And R ² are the same or different alkyl groups,
R ³ and R ⁴ are the same or different
A Le group, a and b are each 0 or 1)
The hydrolyzable organosilicon compound represented or its hydrolyzate 100 parts by weight (b) Organic solvent 200 to 1000 parts by weight (c) Metal oxide fine particles 30 to 200 parts by weight (d) Perchlorate 0.3 To 5 parts by weight (e) General formula (2)

[0012]

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[0013] (wherein, R ⁵ and R ⁶ are alkyl groups the same or different, is a perfluoroalkyl group or a phenyl group, n is 0 or 1) a metal complex of a compound represented by the hydrolysis A coating composition comprising 1 to 50 ppm based on the total amount of possible organosilicon compound or hydrolyzate thereof, organic solvent, metal oxide fine particles and perchlorate.

[0014] The component (a) used in the present invention is as described above.
A disilane compound of the general formula (1) or a hydrolyzate thereof
You.

[0015] Divalent hydrocarbon group represented by the above formula (1)
A typical example of (A) is as follows. (A)

[0016]

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Alkylene groups such as (b) --CH ₂ CH ₂ OCH ₂ CH _2- , --CH ₂ CH ₂ CH
General formula-(CH ₂ ) _p O such as ₂ OCH ₂ CH ₂ CH _2-
An ether group represented by [(CH ₂ ) _q O] _r (CH ₂ ) _p- (where p and q are 2 or 3 and r is 0 or an integer of 1 or more) (c)

[0018]

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[0019] (Here, p is 2 or 3.) Spiro group represented by (d)

[0020]

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[0021]

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A group containing an epoxy group represented by (e)

[0023]

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[0024] The general formula such as

[0025]

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[0026] (wherein, R represents CH ₂ CH ₂ O or, CH ₂
In CH ₂ CH ₂ O, s is an integer of 0 to 4, and t is s = 0.
Is 0 when s = 1, and 1 when s = 1 to 4. A) a carbonate group represented by

In the above formula (1) , R ¹ and R ² are the same or different alkyl groups or alkoxyalkyl groups, and have 1 to 6 carbon atoms, particularly 1 to 3 alkyl groups, or 1 to 3 carbon atoms. 6, particularly an alkoxyalkyl group consisting of 1 to 3 alkyl groups is preferable, and specifically, a methyl group, an ethyl group,
Examples thereof include a propyl group and a methoxyethyl group. R ³ , R ⁴
Are the same or different alkyl groups having 1 to 4 carbon atoms.
Are preferred, and specific examples include a methyl group, an ethyl group, and a propyl group.

In the present invention, the component (a)
Organic silicon compound or its hydrolyzate
And the compound represented by the general formula (1) or its hydrolysis
By using the object, crosslinking as a coating composition, since the staining of the physical properties can you to good said chemical
It is essential to use a compound, but the compound of the above general formula (1)
A known hydrolyzable organosilicon compound,
Can be used by mixing the hydrolysates thereof. So
In the case of the organoalkoxy represented by the following general formula (3)
Sisilane or its hydrolyzate is preferably used
it can.

[0029]

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( Wherein , R ⁷ represents an organic group having 2 to 8 carbon atoms including an epoxy group, a mercapto group or an amino group, an alkyl group having 1 to 6 carbon atoms, an alkenyl group or a halogenated alkyl group, or , An aryl group, R
⁸ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group or an acyl group;
Or 3. The specific examples of such organoalkoxysilanes are as follows. For example, methyltrimethoxysilane, dimethyldimethoxysilane,
Methyltriethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-glycidoxypropyltrimethoxysilane Γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, β
Examples thereof include-(3,4-epoxycyclohexyl) ethyltrimethoxysilane and γ-aminopropyltriethoxysilane, and among them, an organosilicon compound having an epoxy group is particularly preferable.

In the present invention, in order to form a good coat film with the hydrolyzable organosilicon compound, prior to coating the hydrolyzable organosilicon compound on the surface of the molded article, the organic solvent to be described later is coated with an organic solvent. In a dissolved state, it is preferable to carry out hydrolysis with a weakly acidic aqueous solution containing an inorganic acid such as hydrochloric acid or sulfuric acid or an organic acid such as acetic acid. By performing the hydrolysis, the hydrolyzable organosilicon compound may be partially polycondensed. When using two or more organosilicon compounds,
The respective organosilicon compounds may be separately hydrolyzed and then mixed, or may be mixed in advance and then hydrolyzed simultaneously.

Next, as the organic solvent of the component (b) in the present invention, known organic solvents can be used without any limitation. In particular, in the present invention, the following organic solvents can be suitably used. For example, lower alcohols such as methanol, ethanol, propanol, isopropyl alcohol and butanol having 1 to 4 carbon atoms; lower carboxylic acids such as methyl acetate or alkyl esters thereof; ethers such as cellosolve or dioxane;
Ketones such as acetone; halogenated hydrocarbons such as methylene chloride; and aromatic hydrocarbons such as benzene and toluene. These organic solvents can be used alone or in combination of two or more.

The amount of the organic solvent used depends on the amount of the hydrolyzable organosilicon compound or its hydrolyzate 100
It must be from 200 to 1000 parts by weight, preferably from 300 to 700 parts by weight based on parts by weight.

In the present invention, the metal oxide fine particles of the component (c) are used for improving the scratch resistance of the coating film. As the metal oxide fine particles, those known to be used as one component of the coating composition can be used without any limitation. For example, Si, Sb, Al, Au,
Ag, Cu, Ti, Sn, Pt, W, Zr, In, F
Oxides of metals such as e and Be are preferred. These metal oxide fine particles can be used alone or in combination of two or more.

The average particle size of the metal oxide fine particles is not particularly limited, but generally 1 to 500 nm can be suitably used. Such fine metal oxide fine particles are generally available as they are or in the form of a colloidal solution dispersed in a polar solvent such as alcohol. When the metal oxide fine particles are used as a colloid solution, the polar solvent contained in the colloid solution can be the above-mentioned organic solvent, and the amount is calculated by including the amount of the above-mentioned organic solvent.

The amount of the metal oxide fine particles to be used depends on the amount of the hydrolyzable organic silicon compound or the hydrolyzate thereof.
It must be in the range of 30 to 200 parts by weight, preferably 50 to 150 parts by weight, based on parts by weight.

In the present invention, the perchlorate as the component (d) functions as a curing catalyst. By using perchlorate, it is possible to form a coat film having good scratch resistance, abrasion resistance, adhesion and the like at a relatively low temperature in a short time. Examples of the perchlorate include magnesium perchlorate, aluminum perchlorate, zinc perchlorate, ammonium perchlorate, and the like, and magnesium perchlorate is particularly preferably used.

The amount of the perchlorate used should be 0.3 to 5 parts by weight per 100 parts by weight of the hydrolyzable organosilicon compound or its hydrolyzate, and should be 0.8 to 3 parts by weight. It is preferably within the range.

The above-mentioned mixture of the organosilicon compound, the organic solvent, the inorganic fine particles and the perchlorate is preferably used in the above-mentioned coating composition because of the ease of the coating operation. Is recommended to be 10 to 40% by weight.

The most important feature of the present invention is that the following formula (2)

[0041]

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( Wherein , R ⁵ and R ⁶ are the same or different alkyl groups, perfluoroalkyl groups, or phenyl groups, and n is 0 or 1). The point is that it is used in the range of 1 to 500 ppm based on the total amount of the above components (a), (b), (c) and (d). By adding the metal complex, the usable life can be significantly extended to 60 days or more, and in some cases, to 120 days or more without lowering the physical properties of the coat film.

The metal complex in the present invention can be used without any limitation as long as it is a metal complex of the compound represented by the above formula. In particular, compounds having a high effect of extending the usable life in the present invention are specifically exemplified. Then, hexafluoroacetylacetone, trifluoroacetylacetone, dibenzoylmethane, acetylacetone, methyl acetoacetate, ethyl acetoacetate and the like can be mentioned, and as a metal to which these compounds coordinate, copper, iron, magnesium, aluminum, nickel , Cobalt, chromium, zinc, titanium, barium and the like. Particularly preferred metal complexes in the present invention are complexes of divalent metals such as copper, nickel, cobalt, chromium, zinc, and barium using acetylacetone as a chelating agent. These may be used alone or in combination of two or more.

The amount of the metal complex used is as described in (a) above.
1 to 5 based on the total amount of components (b), (c) and (d)
00 ppm, preferably 80-200
ppm. When the amount of the metal complex used is less than 1 ppm, the pot life extension effect is not obtained, and when it exceeds 500 ppm, the metal complex acts as a curing catalyst, which undesirably causes a reduction in the pot life. .

The metal complexes include (a), (b),
Finally, 1 to 5 based on the total amount of the components (c) and (d)
The addition time is not particularly limited as long as it is present at 00 ppm. The most recommended addition methods are (a), (b),
A method of preparing the components (c) and (d) and adding a predetermined amount of the metal complex at the end, or a method of mixing and dissolving the metal complex in the component (b) in advance.

For the purpose of further improving the smoothness of the coating film, a silicone-based or fluorine-based surfactant can be added to the coating composition of the present invention. Further, other various additives such as an ultraviolet absorber, an antioxidant, a dye and a pigment can be used.

The object to be coated with the coating composition of the present invention is not particularly limited. Generally, molded products having low surface hardness and poor scratch resistance and wear resistance, particularly plastic molded products, are mainly used. For example, polyunsaturated esters such as polymethyl methacrylate, polymethacrylate, polyethylene terephthalate, polyacrylate and polymethyl acrylate; polystyrenes; polyvinyl chloride; epoxy resins; polyamides; polycarbonates; and polycarbonates such as polyethylene glycol bisallyl carbonate. Thiourethanes; copolymers such as cellulose acetate plastics, and molded articles formed of copolymers of monomers forming these polymers or copolymers of the monomers and other monomers.

The method for applying the coating composition of the present invention to the surface of a plastic molded article can be used without any particular limitation. For example, a method of dipping a molded article in a solution of a coating composition, spraying the solution, brushing,
A method of applying with a roller or the like is generally adopted. After the application, it is air-dried in dry air or air and heated to form a coat film. The heating temperature varies depending on the molded product, but is 80 ° C. or more, preferably 100 ° C.
Above or a temperature at which the molded product does not deform, generally 150 ° C
The following are preferred. Curing time is about 1 hour at 130 ° C,
Approximately 2 to 4 hours at 100 to 120 ° C is a rough guide.
The coating film formed by curing can have a thickness of about 0.1 to 50 μm, but a thickness of 1 to 10 μm is particularly preferable.

[0049]

Industrial Applicability The coating composition of the present invention has a long working life and a long-term storage stability, and shows the same performance of a coating film as in the case of initial use after long-term storage.

[0050]

EXAMPLES The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The coating film and the coating composition were evaluated by the following methods. (1) Appearance Light from a light collector was applied to visually evaluate the degree of fogging of the coat film. (2) Scratch resistance test Using steel wool manufactured by Nippon Steel Wool Industry Co., Ltd. (# 0000), the degree of scratching after reciprocating 10 times under a load of 1 kg was visually evaluated. The state in which the polydiethylene glycol bisallyl carbonate dough is very easily damaged is denoted by E, and 5 to A to E
It was evaluated on a scale. (3) Viscosity of coating composition The viscosity at 25 ° C was measured using a Cannon-Fenske viscometer. If the viscosity exceeds 7 mPa · s, the abrasion resistance and abrasion resistance of the coat film are reduced, and the commercial value is unfavorably deteriorated.

[0052] After the Examples 1 to 13 and Comparative Examples 1 to 3 (1) mixing and stirring an organic silicon compound and isopropyl alcohol shown below in the formulations shown in the preparation Table 1 of the coating composition uniformly, 0.05
A specified hydrochloric acid aqueous solution was added in an amount necessary for completely hydrolyzing the alkoxy group of the organosilicon compound, and hydrolysis was performed. Thereafter, methanol silica sol (manufactured by Nissan Chemical Industries, Inc., SiO ₂ concentration 30 wt%, average particle diameter 10 to 15 n)
m) and the mixture was aged for 1 day to obtain two types of coating compositions A and B. In each case, the solid concentration is 20w
t%.

[0053]

[Table 1]

[0054] S-1:

[0055]

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[0056] S-2:

[0057]

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[0058] S-3:

[0059]

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[0060] IPA: isopropyl alcohol (2) A and B prepared in blending the above perchlorate (1), the magnesium perchlorate was added 1 part by weight of the organic silicon compound to 100 parts by weight, were mixed And made it even.

[0061] (3) A and B prepared in the metal complex formulation above (2), the organosilicon compound,
The metal complex was added at a ratio shown in Table 2 to the total amount of isopropyl alcohol, methanol silica sol and magnesium perchlorate, and mixed to make uniform.

[0062]

[Table 2]

In Table 2, (acac) is a chelate of acetylacetonate, (maa) is a chelate of methyl acetoacetate, (eaa) is a chelate of ethyl acetoacetate, and (hfaa) is a chelate of hexafluoroacetylacetone. is there.

[0064] (4) a plate coated film poly diethylene glycol bis allyl carbonate which is surface treated with a form 5% sodium hydroxide aqueous solution (3)
Dipped in A and B prepared in the above, pulled up at a speed of 30 cm / min, pre-dried at 80 ° C. for 10 minutes, and then dried at 120 ° C. for 3 minutes.
Time cured.

[0065] The coating composition obtained in (3) and the evaluation results of the obtained coating film (4) shown in Table 3.

[0066]

[Table 3]

[0067] The A obtained in the preparation of (1) coating compositions of Examples 14 to 18 and Comparative Examples 4 and 5 Example 1, the organosilicon compound perchlorate shown in Table 4 100
After adding in an amount based on parts by weight and mixing and uniforming, copper acetylacetonate was added at 100 ppm based on the total amount of the organosilicon compound, isopropyl alcohol, methanol silica sol and magnesium perchlorate,
Mix to make uniform. A coating film was formed from the obtained coating composition in the same manner as in Example 1. Table 4 shows the evaluation results of the obtained coating composition and coat film.

[0068]

[Table 4]

[0069] Preparation of (1) coating compositions of Examples 19 and 20 Example 1, methanol silica sol of tungsten oxide / tin oxide methanol dispersion sol (manufactured by Nissan Chemical Industries, Ltd. SUNCOLLOID
The coating compositions of A and B were obtained in the same manner as in Example 1 except that HIS-30M was changed to a solid content concentration of 30 wt%). In each case, the solid content concentration was 20 wt%.

[0070] Further, the magnesium perchlorate was added 1 part by weight relative to the organic silicon compound to 100 parts by weight was uniformly mixed, an organic silicon compound of copper acetylacetonate, isopropyl alcohol, tungsten oxide / tin oxide 100 ppm was added to the total amount of the methanol-dispersed sol and magnesium perchlorate, and mixed to make uniform. Table 5 shows the evaluation results of the obtained coating composition and coat film.

[0071]

[Table 5]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-222160 (JP, A) JP-A-60-262833 (JP, A) JP-A-2-69585 (JP, A) JP-A-56-222 99263 (JP, A) JP-A-2-279778 (JP, A) JP-A-6-49412 (JP, A) JP-A-7-47613 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) C09D 183/04

Claims (1)

(57) [Claims] 1. A (a) general formula (1) ## STR1 ## (However, A is an element in which the main chain is at least 4 or more linearly.
R ¹ and R ² are the same.
A kind or different kind of alkyl group or alkoxyl group
R ³ and R ⁴ are the same or different alkyl groups;
a and b are each 0 or 1) 100 parts by weight of a hydrolyzable organosilicon compound or a hydrolyzate thereof (b) 200 to 1000 parts by weight of an organic solvent (c) metal oxide fine particles 30 to 200 parts by weight (d) perchlorate 0.3 to 5 parts by weight (e) the general formula (2) ## STR2 ## (Where R ⁵ and R ⁶ are the same or different alkyl group, perfluoroalkyl group or phenyl group, and n is
0 or 1) with respect to the total amount of the hydrolyzable organosilicon compound or its hydrolyzate, organic solvent, metal oxide fine particles and perchlorate. A coating composition comprising: