JP2006257215A - Surface treatment method of aluminum-base product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface treatment method suitable for preventing dirt from adhering to the surface of an aluminum-base product, and for facilitating the adherent dirt to be easily removed. <P>SOLUTION: This surface treatment method is characterized by applying on the surface of the aluminum-base product a surface treating agent (A) comprising an organopolysiloxane (a) having an Si-C bond and a hydrolyzable silyl group, and an organopolysiloxane (b) having no alkoxy group, wherein the content of the component (a) is in the range of 13-99.9 wt% and the content of the component (b) is in the range of 0.1-87 wt%, respectively to the total weight of the components (a) and (b). As the aluminum-base product, one applied with a clear coating is preferable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a surface treatment method suitable for preventing dirt from adhering to an aluminum-based product and easily removing the attached dirt.

  Aluminum products are lightweight and have good workability, and are used in various fields.

  In the general manufacturing process, an aluminum alloy melt is poured into a mold, cooled and solidified, and then taken out from a mold to obtain a product.

  On the surface of such a molded product, fine irregularities occur on the surface due to the transfer of fine processing flaws on the mold and foreign matter adhering to the mold, and conversely, the solution does not enter the gap between the molds. There may be.

  Examples of the aluminum products include aluminum automobile wheels (hereinafter abbreviated as aluminum wheels) which are attachment members such as tubes and tires. Contaminants such as brake dust may adhere to this as the vehicle travels. Brake dust is fine foreign matter generated by friction between parts when the brake is applied. If the surface of the aluminum wheel has fine irregularities or a complicated design, the brakes are There is a problem that it is difficult to remove the dust if it enters.

  For example, a coating film such as a powder primer is provided on an aluminum wheel base material in advance so as to conceal fine irregularities with the coating film. According to this method, fine irregularities can be reduced and removal of adhering brake dust can be facilitated, but the shape of the aluminum wheel has a complicated design. If the coating film is newly damaged, it is necessary to deal with it. Also, since brake dust contains metal powder, it is difficult to remove it once it adheres to the aluminum wheel surface, and it must be cleaned for a long time with a brush etc. using a special cleaner to remove the metal powder. However, the work may damage the aluminum wheel surface. However, if the brake dust is left on the surface, the metal powder will oxidize and it will be more difficult to remove. .

JP 2002-138246 A JP 2002-146277 A JP 2002-194273 A JP 2003-221550 A

  An object of the present invention is to provide a surface treatment method suitable for preventing dirt from adhering to the surface of an aluminum-based product and easily removing the attached dirt.

As a result of intensive studies to solve the above problems, the present inventors have found that the surface of an aluminum-based product has an organopolysiloxane containing a Si—C bond and a hydrolyzable silyl group and an organopolysiloxane containing no alkoxy group. The present invention has been achieved by a surface treatment method characterized by coating a specific surface treatment agent containing siloxane in a specific blending ratio.
That is, the present invention is 1. The surface of the aluminum-based product contains an organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group and an organopolysiloxane (b) containing no alkoxy group, and component (a) and component (b) The surface treatment agent (A) in which the amount of the component (a) is 13 to 99.9% by weight and the amount of the component (b) is 0.1 to 87% by weight with respect to the total weight of A surface treatment method characterized by:
2. 2. The surface treatment method according to item 1, wherein the aluminum-based product is a product coated with a clear paint.
3. The aluminum-based product is obtained by applying a powder paint as a primer paint, applying a base coat paint containing a color pigment on the coated surface, and then applying a clear paint on the base coat coated surface. 2. The surface treatment method according to item 1,
4). Item 4. The surface treatment method according to Item 2 or 3, wherein the clear paint is a powder paint.
5. The organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group contains an organopolysiloxane skeleton having a three-dimensional structure and a linear organopolysiloxane skeleton in the molecule (a1). 5) the surface treatment method according to any one of items 1 to 4,
6). The surface treatment agent (A) contains an organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group in an amount of 13% by weight or more in the treatment agent (A). The surface treatment method according to any one of the items,
7). 7. The organopolysiloxane (b) containing no alkoxy group is a linear polysiloxane and / or a cyclic polysiloxane having a molecular weight in the range of 200 to 1,000. Surface treatment method,
8). Articles processed by the method according to any one of claims 1 to 7,
About.

  According to the surface treatment method of the present invention, by a specific surface treatment agent containing an organopolysiloxane containing a Si-C bond and a hydrolyzable silyl group and an organopolysiloxane containing no alkoxy group at a specific blending ratio, The surface can be appropriately modified to be water-repellent, the contaminants are difficult to adhere, and the adhered contaminants can be easily removed by simple operations, so that the surface has irregularities and / or is complicated. Even an aluminum product having a simple shape can maintain its aesthetics for a long period of time.

  Aluminum-based products to which the method of the present invention is applied are not particularly limited, and examples include aluminum-based products or alloys made of alloys containing magnesium, silicon, etc., such as weight reduction and design properties. It may be formed or cut into an arbitrary shape for the purpose. Further, it may be subjected to shot blasting, polishing or the like.

  Specific examples of the aluminum product in the present invention are not particularly limited, and examples thereof include an aluminum wheel, a machine part, and an aluminum sash.

  In the present invention, the aluminum-based product is preferably a product obtained by subjecting the surface to a chemical conversion treatment in advance with a chromate, a phosphate or a zirconium-based treatment agent from the viewpoint of corrosion resistance.

  The aluminum-based product is preferably a product coated with a clear paint from the viewpoints of surface concavity and convexity concealment, smoothness of the coated surface, glossiness, and weather resistance.

  As the clear coating material, conventionally known coating materials can be used without limitation, and examples thereof include organic solvent-type, water-based, and powder coating materials. Examples of the resin for forming a coating film of the clear paint include acrylic resins, polyester resins, alkyd resins, fluororesins, epoxy resins, polyurethane resins, polyether resins, and the like. These may be used alone or in combination of two or more. Can be used. In the present invention, it is desirable to contain an acrylic resin as a coating film-forming resin in the clear paint from the viewpoint that the weather resistance is good and the refractive index is close to that of the film formed by the surface treatment agent (A) described later.

  The resin for forming a coating film in the clear coating may be a curable type or a lacquer type, and is usually a type having a curable property. In the case of a type having curability, a crosslinking agent such as a melamine resin, a (block) polyisocyanate compound, an amine series, a polyamide series or a polyvalent carboxylic acid can be included.

  In addition to the above-mentioned components, the clear coating composition may contain an anti-settling agent, a curing catalyst, an ultraviolet absorber, an antioxidant, a leveling agent, a surface conditioner, an antifoaming agent, crosslinkable polymer particles (microgel). ) And the like can be appropriately contained. Moreover, a coloring component can also be contained in the range which does not inhibit transparency.

  The drying conditions of the clear coating can be appropriately adjusted according to the composition and the like, and the drying time is 110 to 150 ° C., preferably 120 to 140 ° C., 10 to 60 minutes, preferably 15 to 40 minutes. Can be.

  When the clear coating is applied, it is desirable that the dry film thickness is adjusted to be in the range of 10 to 50 μm, preferably 15 to 40 μm, from the viewpoint of concealing the surface unevenness and weather resistance. In particular, when a powder coating is used as the clear coating, it is desirable to adjust the dry film thickness to be in the range of 20 to 200 μm, preferably 40 to 150 μm.

  In the present invention, the aluminum-based product may be a product coated with a base coat paint containing a color pigment from the viewpoint of surface concavity and convexity concealment and design.

  Such a base coat paint is a paint containing a color pigment and a resin for forming a coating film, and may be an organic solvent system or an aqueous system.

  The above-mentioned colored pigment imparts base concealing properties and coloring, and can be used without limitation from solid pigments and / or bright pigments conventionally used for paints, and is a resin for forming a coating film. Can be used without limitation from those listed in the description of the clear paint. In the present invention, it is desirable that the base coat paint contains an acrylic resin as a coating film forming component from the viewpoint of adhesion to the clear paint and finish.

  In the base coat paint, in addition to the above components, an anti-settling agent, a curing catalyst, an ultraviolet absorber, an antioxidant, a leveling agent, a surface conditioner, an antifoaming agent, a crosslinkable polymer particle (microgel), if necessary. A rust preventive agent and the like can be appropriately contained.

  The drying conditions of the base coat paint can be appropriately adjusted depending on the composition and the like. For example, the drying temperature is 80 to 150 ° C., preferably 100 to 140 ° C. for 10 to 60 minutes, preferably 15 to 40 minutes. Can be time.

  When the base coat paint is applied, it is desirable that the dry film thickness is adjusted to 2 to 30 μm, preferably 5 to 25 μm, from the viewpoints of surface unevenness concealment and base concealability, and internal stress.

  Further, for the purpose of further improving the design properties, after applying the base coat paint containing the color pigment, another base coat paint having a different pigment composition may be applied on the base coat coating surface.

  In the present invention, from the viewpoint of design and weather resistance, the aluminum-based product is preferably a product obtained by applying a base coat paint containing a color pigment and then applying a clear paint on the base coat application surface.

  The colored base coat paint and the clear paint may be cured, respectively, or after the colored base coat paint is applied, the clear paint can be applied uncured and both coating films can be cured simultaneously.

  Further, in the surface treatment method of the present invention, from the viewpoint of surface unevenness concealing property or adhesion to a coating film by the surface treatment agent (A), an aluminum product is used as a primer, and further as a clear, a powder coating material. It is desirable to be painted.

  There is no restriction | limiting in particular as a coating-film formation component of the said powder coating material, It can use without a restriction | limiting from what was listed by description of the said clear coating material, It can use individually or in combination of 2 or more types.

  The above-mentioned powder paints include coloring pigments, fillers, fluidity modifiers, antiblocking agents, surface modifiers, anti-waxing agents, antioxidants, charge control agents, curing accelerators, rust inhibitors, etc. as necessary. Can be contained.

  The drying conditions of the powder coating material can be appropriately adjusted depending on the composition, for example, 140 to 200 ° C., preferably 150 to 180 ° C. for 10 to 60 minutes, preferably 15 to 40 minutes. It can be the drying time.

  In the method of the present invention, when a powder coating is applied, it is desirable that the dry film thickness is adjusted in the range of 20 to 200 μm, preferably 40 to 150 μm, from the viewpoint of concealment concealment and adhesion of the surface.

  In the surface treatment method of the present invention, from the viewpoint of surface unevenness concealing property, coated surface smoothness, design properties, and anticorrosive properties, an aluminum product is coated with a powder paint as a primer, and then on the coated surface, After applying a base coat paint containing a color pigment, and then applying a clear paint on the base coat coating surface, or after applying a powder paint as a primer, a base coat containing a color pigment on the coating surface It is preferable that after the paint is applied, a powder paint is applied as a clear on the base coat coating surface.

Next, the surface treatment agent (A) used in the method of the present invention will be described.
The surface treatment agent (A) used in the present invention contains an organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group and an organopolysiloxane (b) containing no alkoxy group. The amount of component (a) is from 13 to 99.9% by weight, preferably from 16 to 99.9% by weight, more preferably from 30 to 99.9% by weight, based on the total weight of (a) and component (b). The amount of component (b) is 0.1 to 87% by weight, preferably 0.1 to 84% by weight, more preferably 0.1 to 70% by weight.

  When the amount of the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group is less than 13% by weight, the surface unevenness concealing property tends to be insufficient, while when it exceeds 99.9% by weight. There exists a tendency for coating workability to fall.

  Next, each component contained in the surface treating agent (A) used in the present invention will be described.

  As the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group, conventionally known ones can be used without limitation. For example, an organopolysiloxane containing a Si—C bond in the molecule can be used. Examples include a method of hydrolyzing and condensing halosilane and alkoxylating with alcohol; a method of hydrolyzing and condensing organoalkoxysilane containing Si—C bond in the molecule.

  Specifically, as these methods, various conditions can be adopted using an organosilane compound containing at least one selected from organosilane compounds containing Si—C bonds represented by the following formulas (1) to (3) as raw materials. It hydrolyzes and condenses.

In the above formulas (1) to (3), R ¹ is the same or different and is a substituted or unsubstituted hydrocarbon group or a polymerizable unsaturated group, and X is the same or different and is a hydroxyl group, an alkoxy group, Represents a halogen atom.

Specific examples of R ¹ are the same or different, and are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, tert-butyl group, n-pentyl group, i -Pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, i-heptyl group, n-octyl group, i-octyl group, n-nonyl group, n-decyl group, n-octadecyl group, etc. Alkyl group; cycloalkyl group such as cyclopentyl group and cyclohexyl group; aryl group such as phenyl group, tolyl group, xylyl group and naphthyl group; aralkyl group such as benzyl group, phenethyl group and phenylpropyl group; 3-chloropropyl group; Halogenated alkyl group such as 3,3,3-trifluoropropyl group; vinyl group, allyl group, i-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl A cycloalkenyl group such as 2-cyclohexylenyl group, 3-cyclohexylenyl group, 2-vinylcyclohexyl group, 3-vinylcyclohexyl group, 4-vinylcyclohexyl group, 2-vinylphenyl group, 3-vinylphenyl group, 4- Polymerizable unsaturated groups such as vinylphenyl group, 2-allylphenyl group, 3-allylphenyl group, 4-allylphenyl group, 3-allyloxypropyl group, 3- (meth) acryloyloxypropyl group; aminoethyl group, Examples thereof include aminoalkyl groups such as 3-aminopropyl group; glycidoxyalkyl groups such as 3-glycidoxypropyl group.

  On the other hand, X may be the same or different and may be methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, i-butoxy group, tert-butoxy group, n-pentyloxy group, i- Examples thereof include alkoxy groups such as a pentyloxy group, n-hexyloxy group, i-hexyloxy group and phenoxy group; halogens such as chlorine, bromine and fluorine;

  Specific examples of the organosilane compounds represented by the above formulas (1) to (3) include monoalkoxysilanes such as trimethylmethoxysilane; dialkoxysilanes such as dimethyldimethoxysilane and diphenyldimethoxysilane; methyltrimethoxysilane, methyl And trialkoxysilanes such as triethoxysilane and phenyltrimethoxysilane; organohalosilanes such as dimethyldichlorosilane and trimethylchlorosilane; and the like.

  In the present invention, the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group is generally composed mainly of an organosilane compound represented by the formula (1) and / or the formula (2). An organopolysiloxane having a three-dimensional structure is preferable. Moreover, in order to adjust the hardness, flexibility, bending resistance, etc. of the coating, an organosilane compound represented by the formula (3) and / or the formula (4) can be appropriately mixed as a raw material.

  Specific examples of the organosilane compound represented by the above formula (4) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetraphenoxysilane; tetrahalosilanes such as tetrachlorosilane, and the like. Can be mentioned.

  Moreover, the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group is produced by using a bifunctional organosilane compound represented by the formula (2) as a main component. An organopolysiloxane having a linear structure may be used.

  In the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group, the alkoxy group bonded to the silicon atom as the hydrolyzable silyl group, that is, the alkoxysilyl group is caused by moisture or moisture in the air. It is known that it is hydrolyzed to become silanol, and the condensation reaction between silanols proceeds at room temperature. In the present invention, the weight average molecular weight is 200 as the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group from the drying property of the coating film at normal temperature and the strength and coating workability of the coating film to be formed. Organopolysiloxanes having a three-dimensional structure in the range of ~ 30,000, preferably 300 to 25,000 are desirable. In addition, in this specification, a weight average molecular weight is the value which converted the weight average molecular weight measured with the gel permeation chromatograph (The Tosoh Corp. make, "HLC8120GPC") on the basis of the weight average molecular weight of polystyrene. . Columns are “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (both manufactured by Tosoh Corporation, trade names) ), Mobile phase: tetrahydrofuran, measurement temperature: 40 ° C., flow rate: 1 cc / min, detector: RI.

  In order to make it difficult for the coating with the surface treatment agent (A) to adhere to the dirt component and to easily remove the attached dirt component, an organopolysiloxane containing a Si—C bond and a hydrolyzable silyl group is used. It is desirable that (a) has a methyl group as a substituent, and that the methyl group concentration of the organopolysiloxane (a) is 20 mol% or more, preferably 40 mol% or more.

In this specification, the methyl group concentration of the organopolysiloxane (a) can be calculated based on the following formula.
Methyl group concentration (mol%) of organopolysiloxane (a) = (n2 / n1) × 100
n1: Total number of moles of the substituent R ¹ of the organopolysiloxane (a), n2: Number of moles of methyl group in the substituent R ¹ .

  In the present invention, the organopolysiloxane (a) containing the Si—C bond and the hydrolyzable silyl group is used in order to make the surface treatment agent (A) flowing into the recesses or scratches on the surface of the aluminum-based product inconspicuous. ) Has a refractive index of 1.39 to 1.55, preferably 1.45 to 1.55. In this specification, the refractive index is measured with an Abbe refractometer in accordance with JIS K0062.

  In addition, the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group is used as a benzene ring in order to make the surface treatment agent (A) flowing into the concave portion or scratch on the surface inconspicuous. Structures can also be included.

  Further, in the present invention, the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group improves the spreadability, surface unevenness concealing property, and the effect of easily removing attached dirt components. It is desirable to contain an organopolysiloxane (a1) containing both an organopolysiloxane skeleton having a three-dimensional structure and a linear organopolysiloxane skeleton in the molecule.

  Examples of the linear organopolysiloxane skeleton include a structure represented by the following formula (5).

In the formula (5), j represents an integer of ² to 1,000, R ² is the same or different and represents a substituted or unsubstituted hydrocarbon group, and the hydrocarbon group is a saturated group, May be the same or different, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, tert-butyl group, n- Pentyl group, i-pentyl group, n-hexyl group, i-hexyl group, n-heptyl group, i-heptyl group, n-octyl group, i-octyl group, n-nonyl group, n-decyl group, n- Alkyl groups such as octadecyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group; aralkyl groups such as benzyl group, phenethyl group and phenylpropyl group; 3 Halogenated alkyl groups such as chloropropyl group and 3,3,3-trifluoropropyl group, aminoalkyl groups such as aminoethyl group and 3-aminopropyl group; glycidoxyalkyl groups such as 3-glycidoxypropyl group In particular, a methyl group is preferable.

  Examples of the method for producing an organopolysiloxane (a1) containing both an organopolysiloxane skeleton having a three-dimensional structure and a linear organopolysiloxane skeleton in the molecule include (1) alkoxy groups and polymerization in the molecule. A method of reacting an organopolysiloxane having a three-dimensional structure containing a polymerizable unsaturated group with a linear organopolysiloxane containing Si-H groups at both ends, or (2) an alkoxy group in the molecule And a method of reacting an organopolysiloxane having a three-dimensional structure containing a Si—H group with a linear organopolysiloxane containing a polymerizable unsaturated group at both ends.

  Examples of the polymerizable unsaturated group include a vinyl group, an allyl group, an i-propenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group and the like; a 2-cyclohexylenyl group, a 3-cyclohexylenyl group, Cycloalkenyl groups such as 2-vinylcyclohexyl group, 3-vinylcyclohexyl group, 4-vinylcyclohexyl group; vinylphenyl groups such as 2-vinylphenyl group, 3-vinylphenyl group, 4-vinylphenyl group; 2-allylphenyl Group, 3-allylphenyl group, allylphenyl group such as 4-allylphenyl group; 3-allyloxypropyl group, 3- (meth) acryloyloxypropyl group, among others, vinyl due to reactivity with Si-H group A group is desirable.

  In the reactions (1) and (2) above, simple metals such as Ni, Rh, Pd, and Pt and compounds thereof in the presence of an organic solvent such as hexane, pentane, toluene, xylene, etc., if necessary, in accordance with conventional methods The hydrosilylation reaction can be performed using the complex as a catalyst.

  In the reactions (1) and (2) above, in order to minimize the amount of unreacted linear organopolysiloxane and obtain the desired compound without gelation, The functional group (polymerizable unsaturated group or Si-H group) of the organopolysiloxane having a three-dimensional structure is excessive with respect to the functional group (Si-H group or polymerizable unsaturated group) of siloxane. It is desirable to make it.

  The amount of the organopolysiloxane (a1) is 1 to 60% by weight, preferably 3 to 50% by weight, based on the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group. It is desirable from the viewpoints of soil removability and curability (touch drying property).

  In the present invention, the organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group includes “SR2406”, “SR2410”, “SR2420”, “SR2416”, “SR2402”, “AY42-161”. (Toray Dow Corning Silicone Co., Ltd.), FZ-3704, FZ-3511 (Nihon Unicar Co., Ltd.), KC-89S, KR-500, X-40- 9225 "," X-40-9246 "," X-40-9250 "," KR-217 "," KR-9218 "," KR-213 "," KR-510 "," X-40-9227 " , “X-40-9247”, “X-41-1053”, “X-41-1056”, “X-41-1805”, “X-41-1810”, “X-40-265” 1 "," X-40-2308 "," X-40-9238 "," X-40-2239 "," X-40-2327 "," KR-400 "," X-40-175 "," Commercial products such as “X-40-9740” (manufactured by Shin-Etsu Chemical Co., Ltd.) are applicable.

  The organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group is not less than 13% by weight, preferably not less than 20% by weight, in the surface treatment agent (A) from the viewpoint of concavity and convexity concealment on the surface. It is desirable to contain.

  In the present invention, the organopolysiloxane (b) containing no alkoxy group does not substantially hydrolyze itself, and is added to improve spreadability and make the formed film uniform. is there. The organopolysiloxane (b) containing no alkoxy group preferably has a molecular weight in the range of 200 to 1,000, preferably 300 to 700, from the viewpoint of spreadability. (6) Or the linear polysiloxane and / or cyclic polysiloxane which are represented by the following Formula (8) can be mentioned.

  As said linear polysiloxane compound, the compound represented by the following Formula (6) can be mentioned.

R ³ is the same or different and represents a substituted or unsubstituted hydrocarbon group, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, tert-butyl. Group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group and other alkyl groups; cyclopentyl group, cyclohexyl group and other cycloalkyl groups; phenyl group and other aryl groups; benzyl group and phenylpropyl group An aralkyl group such as an aminoalkyl group such as an aminoethyl group and a 3-aminopropyl group; a glycidoxyalkyl group such as a 3-glycidoxypropyl group and the like. Groups, in particular methyl groups, are preferred. Y represents a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a polyoxyalkylene group represented by the following formula (7). When Y is an alkyl group, for example, an n-hexyl group, i -Hexyl group, n-heptyl group, i-heptyl group, n-octyl group, i-octyl group, n-nonyl group, n-decyl group and the like, among which an alkyl group having 6 to 9 carbon atoms is preferable. . k1 represents an integer of 1 to 8, and k2 represents an integer of 1 to 8. In the compound represented by the above formula (6), it is preferable that k1 and k2 are both 1 because the spreadability of the surface treatment agent of the present invention is excellent.
_{^{-O- (CHR 4 -CH 2 -O)}} k3 -R 41 (7)
k3 represents an integer of 1 to 20, preferably 2 to 20, and R ⁴ represents a methyl group or a hydrogen atom. R ⁴¹ represents hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms, particularly preferably hydrogen or a methyl group.

  In the linear organopolysiloxane compound represented by the above formula (6), by introducing a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms or a polyoxyalkylene group as Y, hydrophilicity / hydrophobicity of the compound It is possible to control the degree of compatibility and to help improve compatibility with the organopolysiloxane (a) containing Si—C bonds and hydrolyzable silyl groups, and to improve the adhesion of the film by the treatment agent (A). it can.

  Examples of the cyclic polysiloxane compound that can be used as the organopolysiloxane (b) include compounds represented by the following formula (8).

R ⁵ is the same or different and represents a substituted or unsubstituted hydrocarbon group, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, tert-butyl. Group, n-pentyl group, i-pentyl group, n-hexyl group, i-hexyl group and other alkyl groups; cyclopentyl group, cyclohexyl group and other cycloalkyl groups; phenyl group and other aryl groups; benzyl group and phenylpropyl group An aralkyl group such as an aminoalkyl group such as an aminoethyl group and a 3-aminopropyl group; a glycidoxyalkyl group such as a 3-glycidoxypropyl group and the like. Groups, in particular methyl groups, are preferred. l represents an integer of 3 to 10. Specific examples of suitable cyclic polysiloxane compounds include methylcyclopolysiloxanes such as decamethylcyclopentasiloxane, octamethylcyclotetrasiloxane, and dodecamethylcyclohexasiloxane.

  The above exemplified compounds may be used singly or in combination.

  In the said surface treating agent (A), in order to improve the sclerosis | hardenability of the formed film obtained, it is desirable to include an organometallic compound. Examples of the organometallic compound include diacetyltin diacetate, dibutyltin dilaurate, dibutyltin diacetate, dioctyltin dilaurate, diacetyltin dioctoate, tin octylate, dibutyltin diacetate, and dibutyltin dioctoate; aluminum trimethoxy Organic aluminum compounds such as aluminum tris (acetylacetonate), aluminum tri-n-butoxide, aluminum tris (acetoacetate ethyl), aluminum diisopropoxy (acetoacetate ethyl), aluminum acetylacetonate; titanium tetra (monoethyl) Ethoxide), titanium tetra (monoethyl ethoxide), titanium tetra (monobutyl ethoxide), titanium tetrakis (acetylacetate) ), Organic titanium compounds such as tetranormal butyl titanate; zirconium tetra (monomethyl ethoxide), zirconium tetra (monoethyl ethoxide), zirconium tetra (monobutyl ethoxide), zirconium normal propylate, zirconium normal butyrate, Organic zirconium compounds such as zirconium tetrakis (acetylacetonate); organic zinc compounds such as zinc naphthenate; organic cobalt compounds such as cobalt octylate and cobalt naphthenate; trimethyl borate, triethyl borate, tripropyl borate, boric acid Boric acid compounds such as boric acid esters such as tributyl, triphenyl borate, tri (4-chlorophenyl) borate, trihexafluoroisopropyl borate, and the like. In combination it can be used for more than species. Among these, an organic titanium compound or an organoaluminum compound is preferable from the viewpoint of curability and ease of use. The organometallic compound is contained in the surface treatment agent (A) in an amount of 0.1 to 10% by weight, preferably 0.5 to 7% by weight.

  The surface treatment agent (A) is desirably blended with a dehydrating agent from the viewpoint of storage stability. As the dehydrating agent, a dehydrating agent known per se can be used. Specifically, aluminum isopropylate, aluminum sec-butyrate, tetraisopropyl titanate, tetranormal butyl titanate, zirconium normal butyrate, ethyl silicate, Metal alkoxides such as vinyltrimethoxysilane; Organic alkoxy compounds such as methyl orthoformate, ethyl orthoformate, methyl orthoacetate, ethyl orthoacetate, orthopropyl ortho orthoacetate, dimethoxypropane; “Additive TI” (trade name, Sumitomo Bayer Urethane Monofunctional isocyanates such as those manufactured by Kogyo Co., Ltd., and these can be used alone or in combination of two or more. The mixing ratio of the dehydrating agent is generally 0.1 to 5% by weight, preferably 0.3 to 3% by weight, in the surface treatment agent (A).

  The surface treatment agent (A) can contain an organic solvent for the purpose of adjusting the coating workability and the curing speed. Examples of such organic solvents include aliphatic organic solvents such as n-hexane, n-octane, i-octane, n-nonane, cyclohexane, methylcyclohexane and mineral spirits; “Swazole 100” (product of Maruzen Petrochemical Co., Ltd.) Petroleum organic solvents such as petroleum ether, petroleum benzene and petroleum naphtha; aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester organic solvents such as butyl acetate These can be used alone or in combination of two or more. In general, the organic solvent can be contained in the surface treatment agent (A) in an amount of 50% by weight or less, preferably 40% by weight or less.

  The surface treatment agent (A) can include a color pigment such as a solid pigment or a glitter pigment and / or a colorant such as a dye, and the hue can be adjusted according to the intended appearance.

  The surface treatment agent (A) further includes a hydrophilic decontaminating agent such as an organosilicate compound; a polytetrafluoroethylene, a compound containing a perfluoroalkyl group, a hydrocarbon group having 6 or more carbon atoms, if necessary. Water repellency-imparting agent such as alkoxysilane and silicone oil containing; A modifying resin such as acrylic resin, urethane resin, epoxy resin, amino resin, polyester resin, acrylic silicon resin, fluorine resin; titanium oxide having photocatalytic activity; Needle-like single crystal inorganic powders such as zinc whiskers; silane coupling agents; titanium coupling agents; colloidal silica, resin particles, surface conditioners, viscosity modifiers, UV absorbers, light stabilizers, antioxidants, interfaces Additives such as activators, film-forming aids, thickeners; cross-linking agents such as isocyanate compounds and melamine resins; Rukoto can.

The surface treatment agent (A) preferably has a kinematic viscosity in the range of ¹ to 300 mm ² / s, preferably 3 to 250 mm ² / _S , from the viewpoint of coating workability and surface unevenness concealing property. In this specification, the kinematic viscosity is obtained by measuring the outflow time of the sample using a Canon-Fenske viscometer holder in accordance with the JIS K 2283 kinematic viscosity test method at a temperature of 25 ° C. It is a calculated value.

  Examples of the coating method of the surface treatment agent (A) include conventionally known methods such as a method of spreading the surface treatment agent (A) with a spreading material, spray coating, brush coating, dip coating, roll coating, and the like. Then, if necessary, the excess can be wiped off with a wiping material.

  The material of the coating material is not limited as long as it is a material that does not damage the surface of the aluminum-based product and is not affected by the surface treatment agent (A), such as polyester, polypropylene, acrylic, cotton, silk, hemp, wool, polyurethane, Nylon etc. are mentioned, and the shape can be appropriately selected. Examples thereof include sponge, cloth, flannel, felt and fleece. Moreover, as a wiping material, the same material and shape as those listed in the description of the spreading material can be appropriately selected and used.

  According to the surface treatment method of the present invention, after the surface treatment agent (A) is applied to the surface of an aluminum-based product, it is possible to easily remove the dirt component adhering to the treatment film.

  Examples of the soil component include metal, sand, soil, bird droppings, oil, scale, pollen, oil smoke, carbon, acid rain, and the like.

  As a method of removing the dirt component, a method of wiping the treatment film with the surface treatment agent of the present invention by impregnating the above-described coating spreading material with the cleaning liquid, and a method of directly applying the cleaning liquid to the processing film And a method of wiping after directly applying the cleaning liquid to the treatment film. The cleaning liquid can be appropriately selected according to the type of the soil component such as water, a surfactant aqueous solution, or an organic solvent.

  Moreover, in the surface treatment method of the present invention, it is possible to prevent the adhesion of dirt components and to easily remove the dirt components by simply applying the surface treatment agent (A), and to protect aluminum products for a long period of time. However, if necessary, a conventionally known wax such as a water-sliding wax containing a hydroxyl group-containing siloxane polymer and a polyisocyanate compound, a polishing agent, or the like is applied onto the coating film formed by the surface treatment agent (A). May be.

  Next, an Example is given and this invention is demonstrated more concretely.

“Part” and “%” indicate “part by weight” and “% by weight”, respectively.

Coating of aluminum alloy castings Production Example 1
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate specified in JIS H 5202-1955, “Majicron ALC-100” "Clear" (trade name, organic solvent type clear paint containing acrylic resin and melamine resin, manufactured by Kansai Paint Co., Ltd.) is spray-coated to a dry film thickness of 25 µm and baked at 140 ° C for 30 minutes to form a top coat film Thus, a painted aluminum alloy casting I was obtained.
Production Example 2
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate specified in JIS H 5202-1955, “Eva Clad NO. 2100 “Primer” (manufactured by Kansai Paint Co., Ltd., trade name, powder primer paint containing epoxy resin and polyester resin) was electrostatically applied to a dry film thickness of 100 μm and cured by heating at 160 ° C. for 30 minutes. Furthermore, “Magiclon AL-2500 Silver” (trade name, organic solvent type base coat paint containing aluminum pigment, acrylic resin and melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained powder coating film has a dry film thickness of 15 μm. Spray coating is performed so that “Magiclon ALC-100 Clear” (manufactured by Kansai Paint Co., Ltd., trade name, organic solvent-type clear paint containing acrylic resin and melamine resin) is left uncured to a dry film thickness of 25 μm. Spray coating was performed as described above, and baking was performed at 140 ° C. for 30 minutes to form a top coat film, thereby obtaining a coated aluminum alloy casting II.
Production Example 3
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate specified in JIS H 5202-1955, “Eva Clad NO. 2100 “Primer” (trade name, powder primer paint containing epoxy resin and polyester resin, manufactured by Kansai Paint Co., Ltd.) was electrostatically applied to a dry film thickness of 100 μm, and cured by heating at 160 ° C. for 30 minutes. Furthermore, “WBC-710 Silver” (trade name, aqueous base coat paint containing an aluminum pigment, an acrylic resin and a melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained powder coating film so that the dry film thickness becomes 15 μm. After spray coating, spray “Magiclon ALC-100 Clear” (trade name, organic solvent type clear paint containing acrylic resin and melamine resin) with a dry film thickness of 25 μm. It was painted and baked at 140 ° C. for 30 minutes to form a top coat film, and a painted aluminum alloy casting III was obtained.

Production Example 4
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate specified in JIS H 5202-1955, “Eva Clad NO. 2100 “Primer” (trade name, powder primer paint containing epoxy resin and polyester resin, manufactured by Kansai Paint Co., Ltd.) was electrostatically applied to a dry film thickness of 100 μm, and cured by heating at 160 ° C. for 30 minutes. Furthermore, “Magiclon ALC-100 Black” (trade name, organic solvent type base coat paint containing black pigment, acrylic resin and melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained powder coating film has a dry film thickness of 25 μm. Then, it was spray-coated so as to be cured by heating at 140 ° C. for 30 minutes. Further, "Magiclon AL-2200PT Silver" (trade name, organic solvent type base coat paint containing an aluminum pigment, an acrylic resin and a melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained coating film has a dry film thickness of 0.1. Spray paint to 0.5 μm, and leave uncured “Magiclon ALC-100 Clear” (manufactured by Kansai Paint Co., Ltd., trade name, organic solvent type clear paint containing acrylic resin and melamine resin) Spray coating was performed to a thickness of 25 μm, and baking was performed at 140 ° C. for 30 minutes to form a top coat film. Thus, a coated aluminum alloy casting IV was obtained.
Production Example 5
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate defined in JIS H 5202-1955, “Eva Clad No. 5600 (Kansai Paint Co., Ltd., trade name, powder clear paint containing acrylic resin and dodecanoic acid) was electrostatically applied to a dry film thickness of 100 μm and cured by heating at 160 ° C. for 30 minutes. Furthermore, “Magiclon AL-2500 Silver” (trade name, organic solvent type base coat paint containing aluminum pigment, acrylic resin and melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained powder coating film has a dry film thickness of 15 μm. Spray coating is performed so that “Magiclon ALC-100 Clear” (manufactured by Kansai Paint Co., Ltd., trade name, organic solvent-type clear paint containing acrylic resin and melamine resin) is left uncured to a dry film thickness of 25 μm. Spray coating was performed as described above, and baking was performed at 140 ° C. for 30 minutes to form a top coat film, whereby a coated plate V of a coated aluminum alloy cast was obtained.
Production Example 6
After performing chemical conversion treatment using “AL-1000” (trade name, chromate chromate, manufactured by Nihon Parkerizing Co., Ltd.) on an aluminum alloy cast AC4C plate specified in JIS H 5202-1955, “Eva Clad NO. 2100 “Primer” (trade name, powder primer paint containing epoxy resin and polyester resin, manufactured by Kansai Paint Co., Ltd.) was electrostatically applied to a dry film thickness of 100 μm, and cured by heating at 160 ° C. for 30 minutes. Furthermore, “Magiclon AL-2500 Silver” (trade name, organic solvent type base coat paint containing aluminum pigment, acrylic resin and melamine resin) manufactured by Kansai Paint Co., Ltd. on the obtained powder coating film has a dry film thickness of 15 μm. The base coat film was formed by spray coating so as to be baked at 140 ° C. for 30 minutes. On the obtained base coat film, “Evaclad No. 5600” (trade name, powder clear paint containing acrylic resin and dodecanoic acid, manufactured by Kansai Paint Co., Ltd.) is electrostatically applied so that the dry film thickness becomes 80 μm. Baked at 160 ° C. for 30 minutes to form a top coat film, and a painted aluminum alloy casting VI was obtained.

Production Example 7 of Organopolysiloxane 7
To a three-necked flask, 80 parts of methyltrimethoxysilane and 20 parts of dimethyldimethoxysilane were added, and 10 parts of 0.05N aqueous hydrochloric acid was added dropwise with stirring, followed by hydrolysis and condensation at 68 ° C. for 1 hour. This was heated to 120 ° C. to remove by-product methanol and filtered to obtain organopolysiloxane A containing a hydrolyzable silyl group. The kinematic viscosity was 200 mm ² / s, and the refractive index was 1.41.
Production Example 8
To a three-necked flask, 80 parts of methyltrimethoxysilane and 20 parts of dimethyldimethoxysilane were added, and 10 parts of 0.05N aqueous hydrochloric acid was added dropwise with stirring, followed by hydrolysis and condensation at 68 ° C. for 2 hours. This was heated to 120 ° C. to remove by-product methanol and filtered to obtain organopolysiloxane B containing a hydrolyzable silyl group. The kinematic viscosity was 500 mm ² / s, and the refractive index was 1.41.

Production Example 9
To a three-necked flask, 85 parts of methyltrimethoxysilane and 15 parts of vinylmethyldimethoxysilane were added, and 15 parts of 0.05N aqueous hydrochloric acid was added dropwise with stirring, followed by hydrolysis and condensation at 68 ° C. for 2 hours. This was heated to 120 ° C. to remove byproduct methanol and filtered to obtain polyorganosiloxane C. Next, 250 parts of polyorganosiloxane C is added to another three-necked flask, 125 parts of dimethylsiloxane oil having both ends Si—H group as a component having a linear dimethylsiloxane skeleton (note), “CAT-PL-50T” ( (Trade name, manufactured by Shin-Etsu Chemical Co., Ltd., Pt-based catalyst) 1.5 parts is added, hydrosilylation reaction is performed at 80 ° C. for 8 hours, this is subjected to reduced pressure treatment at 120 ° C. and 10 mmHg for 2 hours, filtered, and three-dimensional An organopolysiloxane D containing both an organopolysiloxane skeleton having a structure and a linear dimethylpolysiloxane skeleton in the molecule and containing a hydrolyzable silyl group was obtained. The kinematic viscosity was 250 mm ² / s, and the refractive index was 1.41.
(Note) Dimethylsiloxane oil: H- [Me ₂ SiO] ₁₉ -Me ₂ Si-H as a main component.

Production Example 10
100 parts of methyltrimethoxysilane was added to a three-necked flask, and 10 parts of 0.05N aqueous hydrochloric acid was added dropwise with stirring, followed by hydrolysis and condensation at 68 ° C. for 2 hours. This was heated to 120 ° C. to remove byproduct methanol and filtered to obtain organopolysiloxane E containing hydrolyzable silyl groups. The kinematic viscosity was 50 mm ² / s, and the refractive index was 1.41.
Production of surface treatment agent Production Examples 11 to 15
Each component was mix | blended with the compounding composition of Table 1, and each surface treating agent (A1)-(A5) was manufactured.

Example 1
Obtained by spreading the surface treatment agent (A1) obtained in Production Example 11 on the casting I obtained in Production Example 1 using a cloth and then wiping it with another clean cloth until there is no unevenness. The obtained surface treatment agent-coated product was used as a test specimen.
Examples 2-30
A test body was obtained in the same manner as in Example 1 except that the combination of the casting and the surface treatment agent in Example 1 was as shown in Table 2 below.
Comparative Examples 1-6
The castings obtained in Production Examples 1 to 6 (no surface treatment agent applied) were used as test bodies for comparative examples.
Performance evaluation The performance evaluation of each test body obtained by the said Example and the comparative example was performed. The results are shown in Table 2.

Dirt removal property Each test body obtained in the above Examples and Comparative Examples was exposed to the outdoors for 3 months, and then the ease of removal of dirt attached to each test body was evaluated according to the following criteria.
◎: Dirt on the smooth surface and cast skin recesses can be cleaned simply by washing the exposed test specimen with water. △: After the exposed specimen is washed with water, even if it is wiped with a cloth, dirt remains in the concave portion of the cast skin. ×: The exposed specimen is washed with water and wiped with a cloth. Dirt remains on the concave part of the casting surface.

Claims (8)

The surface of the aluminum-based product contains an organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group and an organopolysiloxane (b) containing no alkoxy group, and component (a) and component (b) The surface treatment agent (A) in which the amount of the component (a) is 13 to 99.9% by weight and the amount of the component (b) is 0.1 to 87% by weight with respect to the total weight of A surface treatment method comprising: The surface treatment method according to claim 1, wherein the aluminum-based product is a product coated with a clear paint. The aluminum-based product is obtained by applying a powder paint as a primer paint, applying a base coat paint containing a color pigment on the coated surface, and then applying a clear paint on the base coat coated surface. 2. The surface treatment method according to claim 1, wherein the surface treatment method is performed. The surface treatment method according to claim 2 or 3, wherein the clear paint is a powder paint. The organopolysiloxane (a) containing a Si—C bond and a hydrolyzable silyl group contains an organopolysiloxane skeleton having a three-dimensional structure and a linear organopolysiloxane skeleton in the molecule (a1). 5) The surface treatment method according to any one of claims 1 to 4, further comprising: The surface treatment agent (A) contains 13% by weight or more of organopolysiloxane (a) containing a Si-C bond and a hydrolyzable silyl group in the treatment agent (A). 6. The surface treatment method according to any one of 5 above. The organopolysiloxane (b) containing no alkoxy group is a linear polysiloxane and / or a cyclic polysiloxane having a molecular weight in the range of 200 to 1,000. Surface treatment method. An article treated by the method of any one of claims 1-7.