JP2010259971A - Composite material having fingerprint adhesion-resistant coating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material having excellent fingerprint adhesion resistance which has a coating film inconspicuous in stuck fingerprints or dirts from the hand. <P>SOLUTION: The composite material has the fingerprint adhesion-resistant coating film, which contains silicon compound and hydrophilic metal oxide fine particles having the average particle size of 1-100 nm and is formed on the surface of a substrate, wherein the glossiness of the coating film is defined as ≤8 and the color difference is defined as <4.6. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composite material excellent in fingerprint adhesion resistance having a coating film in which an attached fingerprint is not noticeable or hardly noticeable.

  Conventionally, articles such as furniture, building materials, and electrical appliances that come into contact with human products are not only dusty and dusty, but also oily contaminants attached to the surface of human hands such as fingerprints and dirt. The aesthetics were impaired and unsightly, and the wiping work to remove was troublesome.

  Accordingly, various methods have been studied in the past for preventing fingerprints, hand stains, and the like from adhering to the surface, or for facilitating removal of attached fingerprints, hand stains, and the like. As a technique for imparting antifouling property, oil repellency, etc. to the surface of a substrate such as a steel plate by a fluorine-based resin coat, for example, a surface treatment agent made of perfluoropolyether-modified silane is known as an oil repellent film (Patent Document) 1). However, although the fluorine resin coating can prevent the adhesion of dirt components such as oil to some extent, the fluorine resin itself has no self-coating action, and naturally the dirt components adhering to the surface are not. Work such as wiping off was necessary.

  Even if oils or fingerprints adhere, it is possible to decompose organic substances such as oils and fingerprints by forming a thin film of photocatalyst on the surface of the base material, and to remove dirt on the base material surface, for example, It has been proposed as a paint in which an effective amount of a visible light reaction type photocatalyst is blended in an organic solvent containing a fluorine-based resin (Patent Document 2). However, the visible light reaction type photocatalyst is expensive, and even in the visible light reaction type, the decomposition action of the organic matter is weak in the room and sufficient fingerprint resistance is not obtained.

  There is a difference in touch feeling when touching the surface with a smooth flat finish on the decorative board and embossed finish with an uneven surface, and it is a touch characteristic peculiar to the resin of the synthetic resin decorative board. It is easy to mark and there is no light touch. Therefore, it has been proposed that the surface of the resin impregnated paper with 1 to 40 parts by weight of protein powder added to 100 parts by weight of the solid content of the resin liquid is less likely to have fingerprint marks or stains (patent) Reference 3).

  In addition, as a fingerprint adhesion prevention technology, the oleic acid contact angle on the surface of the coating is 15 degrees or less so that the attached fingerprint is not noticeable, and the attached fingerprint is greatly wetted and spread to make the fingerprint inconspicuous Building materials have been proposed (Patent Document 4). Furthermore, by forming a coating film with a ratio of resin and fine particles having a particle diameter of 0.3 to 1.0 μm in the ratio of 100: 20 to 500 on the surface of the portable information device, fingerprint marks, peeling portions and others It has also been proposed to make the glossiness inconspicuous so that there is no difference in the glossiness from this point (Patent Document 5).

  However, the thing of patent document 4 is a mirror-finished building material, and a use is limited, and the thing of patent document 5 is a fine particle of the range of 0.3-1.0 micrometer of particle diameter with respect to resin 100. Although the mass ratio is required as large as 20 to 500 and there is no difference in the glossiness between the fingerprint mark or the peeled portion and the other portions, there is no particular difference in the glossiness. It is not considered whether it should be. As described above, there has been no practically satisfactory technique for preventing adhesion of fingerprints that prevents the attached fingerprints and dirt from being noticeable.

JP 2003-238777 A JP 2007-146041 A JP 2005-199495 A JP 2007-313686 A JP 2007-169310 A

  An object of the present invention is to provide a composite material excellent in anti-fingerprint adhesion having a coating film in which attached fingerprints and hand stains are not noticeable.

  As a result of intensive research to solve the above problems, the present inventors have formed a fingerprint-resistant coating film containing a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm on the surface of the substrate. It was found that the above-mentioned problems can be solved by using a composite material having a fingerprint-resistant coating film having a glossiness of 8 or less and a color difference of less than 4.6.

  In the present invention, a hydrophilic metal oxide fine particle having an average particle diameter of 1 to 100 nm is added to a coating agent containing a silicon compound so that the gloss of the coating film is 8 or less and the color difference is less than 4.6. With a structure that scatters and prevents glare, fingerprints and hand stains can be made inconspicuous, and there is no need to wipe off dirt components attached to the surface, and fingerprint resistance can be maintained for a long time. It was possible to provide a composite material having an excellent coating film.

That is, the present invention
[1] A composite material comprising a substrate and a fingerprint-resistant coating film comprising a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm formed on the surface of the substrate, the gloss of the coating film A composite material on which a fingerprint-resistant coating film having a degree of 8 or less and a color difference of less than 4.6 is formed.
[2] The composite material according to [1], wherein the silicon compound is at least one selected from alkoxysilane, alkylalkoxysilane, and chlorosilane.
[3] The composite material as described in [2] above, wherein the alkoxysilane is a tetraalkoxysilane and the alkylalkoxysilane is an alkyltrialkoxysilane.
[4] The composite material according to any one of [1] to [3], wherein the hydrophilic metal oxide fine particles are silica.
[5] The composite according to any one of [1] to [4], wherein the hydrophilic metal oxide fine particles are contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the silicon compound. Wood.
[6] The composite material according to any one of [1] to [5], wherein the substrate is a decorative board.
[7] The composite material according to [6], wherein the decorative board is a melamine decorative board.

  A fingerprint-resistant coating film containing a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm and having a glossiness of 8 or less and a color difference of less than 4.6 is formed on the surface of the substrate. Composite material could be provided. The fingerprint-resistant coating film is not only fingerprint-resistant, but also has a high strength of the cured film itself and excellent scratch resistance, and can be easily and simply formed by applying to the substrate surface. it can.

The present invention is described in detail below.
The composite material of the present invention has a substrate, a fingerprint-resistant coating film containing a silicon compound formed on the surface of the substrate and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm. It is a composite material on which a fingerprint-resistant coating film having a glossiness of 8 or less and a color difference of less than 4.6 is formed.

The anti-fingerprint coating film of the present invention comprises a hydrolysis reaction and polycondensation (dehydration condensation) of a coating solution containing a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm in the presence of water and a catalyst. A siloxane bond is formed through a reaction to form a cured film of a polysiloxane compound. The film becomes dense by drying and heat treatment, the strength of the cured film itself is high, and the scratch resistance is also excellent. The present invention is the formation of a cured film by a so-called sol-gel method.
If the surface of the substrate to be coated with the coating liquid is made hydrophilic, a hydroxyl group on the surface and alkoxysilane form a covalent bond, so that a normally durable film is formed. It is not necessary for the surface of the substrate to be hydrophilic, and it is only necessary to clean the surface of the substrate.

  The fingerprint-resistant coating film of the present invention is a water-repellent coating film, and the silicon compound forming the coating film is selected from alkoxysilane, alkylalkoxysilane, and chlorosilane. Alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, 1,3-dimethyltetramethoxydisiloxane, 1,3-dimethyltetraethoxydisiloxane, 1,3-dioctyltetramethoxydioxane. 1,3-dioctyltetraethoxydioxane, etc., as the alkyl alkoxysilane, methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltri Methoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyl Triethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, (3-cyclopentadienylpropyl) trimethoxysilane, (3- Cyclopentadienylpropyl) triethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, tolyltrimethoxysilane, tolyltriethoxysilane, benzyltrimethoxylane, benzyltriethoxylane, etc. As chlorosilane, methyltrichlorosilane, methyl Dichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, 3-chloropropyltrimethoxysilane, 3-chloropropiyl Triethoxysilane, chlorophenyltrimethoxysilane, chlorophenyltriethoxysilane, chloropropyltrimethoxysilane, chloropropyltriethoxysilane, chlorophenyltrimethoxysilane, ((chloromethyl) phenylethyl) trimethoxysilane, ((chloromethyl) phenylethyl ) Triethoxysilane and the like, and at least one or more of them can be used.

  Among these, silicon compounds include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, and hexyltrimethoxysilane. , Hexyltriethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, In particular, it is more preferable to use octyltrimethoxysilane, decyltrimethoxysilane, or decyltriethoxysilane.

The hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm used in the present invention are metal oxides, and are silicon oxide, aluminum oxide, tin oxide, iron oxide, titanium oxide, chromium oxide, zinc oxide, zirconium oxide, alumino. One type selected from silicate, talc, etc., or a mixture of a plurality of types. The average particle diameter is in the range of 1 to 100 nm on the order of nm. Preferably it is the range of 5-20 nm. If it is less than 1 nm, the cohesive force between the fine particles becomes strong, and it is difficult to handle in order to disperse it uniformly in the coating liquid, and if it exceeds 100 nm, whitening of the coating film appears remarkably. In addition, in this invention, the diameter of an average particle diameter measures the diameter of the particle | grains of 3,000-5,000 from an electron micrograph, and regards the arithmetic average as an average particle diameter.
The nano-order hydrophilic metal oxide fine particles of the present invention are more preferably silicon oxide (silica), which is easily available as commercially available nanoparticles.

Examples of the solvent used in the coating solution of the present invention include alcohols such as methanol, ethanol, propanol, butyl alcohol, and amyl alcohol. Among them, chain saturation having a large evaporation rate at room temperature and having 3 or less carbon atoms. It is preferable to use a monohydric alcohol. The acid catalyst used in the coating solution is preferably a volatile acid such as hydrochloric acid, hydrofluoric acid, nitric acid, acetic acid, and formic acid from the viewpoint that it volatilizes by drying at room temperature and does not remain in the film. Moreover, hydrochloric acid that is relatively easy to handle is particularly preferred.
Add a silicon compound to the solvent and stir, then add water and acid for hydrolysis and stir, and if necessary, stir at room temperature for 1 to 3 days to prepare a base solution. Next, the base solution is diluted with a solvent having the same weight, and the hydrophilic metal oxide fine particles are mixed in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of the diluted base solution. When the content of the hydrophilic metal oxide fine particles is less than 0.01 parts by weight or more than 10 parts by weight, the glossiness and color difference of the anti-fingerprint coating film cannot be made within the scope of the present invention, and adherence The fingerprint is conspicuous.

  Usually, the surface state of a coating film can represent the interface state with respect to the liquid, solid, etc. of the outermost surface of a film by a water contact angle, and can evaluate from hydrophilicity to hydrophobicity. Therefore, the inventors measured the water contact angle for the fingerprint-resistant coating film of the present invention. In the present invention, the base agent which is the main component of the coating liquid exhibits a water contact angle of 85 degrees or more, exhibits hydrophobicity, and can be referred to as a water-repellent coating.

  Next, the oleic acid contact angle was measured for the anti-fingerprint coating film of the present invention. Conventionally, as described in Patent Document 4, for example, an oleic acid contact angle has been used for evaluation of fingerprint resistance. That is, the main component of fingerprints is sebum, which consists of neutral fat (triglyceride, etc.) and fatty acids (such as oleic acid and palmitic acid) decomposed by neutral fat. Thus, the fingerprint resistance was evaluated.

  In the present invention, when the oleic acid contact angle was measured, the adhesion resistance to fingerprints was sufficiently excellent even if it was not less than 15 degrees as described in Patent Document 4. Further, it has been found that when the content of the hydrophilic metal oxide fine particles is increased and the oleic acid contact angle is lowered, the oleic acid soaks into the coating film and a fingerprint mark remains. Therefore, the metal oxide fine particles are more preferably mixed in the range of 0.01 to 5 parts by weight. Furthermore, when the amount is 0.5 parts by weight or more in this range, oleic acid partially permeates into the coating film, and the oleic acid trace may be slightly noticeable depending on the state of the light beam. Even more preferably, it is less than 5 parts by weight.

  In the coating liquid of the present invention, the glossiness and color difference of the anti-fingerprint adhesive coating film are within the range where the scope of the present invention can be achieved, and the performance required for the coating film other than the improvement of the anti-fingerprint adhesion is exhibited. Of various components. Such components can include solvents, surfactants, curing agents, pigments, leveling agents, antifoaming agents, wetting agents, preservatives, and the like.

  In the present invention, the anti-fingerprint coating film has a glossiness of 8 or less and a color difference of less than 4.6. Within this range, it is possible to achieve a structure in which reflected light is scattered and glare is suppressed, and fingerprint marks, hand stains, and the like can be made inconspicuous. Preferably, the lower limit of glossiness is 1 or more, and the lower limit of color difference is 1.0 or more. More preferably, the glossiness is 2 or more and 8 or less, and the color difference is 1.0 or more and 4.4 or less. When the glossiness exceeds 8, it is close to the glossiness of the substrate itself, and an effect as an anti-fingerprint coating cannot be found. When the color difference is 4.6 or more, the color becomes completely different from that of the original substrate, and there is a problem in design.

  As the substrate for forming the composite material of the present invention, various materials such as metal, glass, plastic, ceramics, stone, wood board, particle board, and paper can be used. Among them, it can be used as a decorative board used for furniture and building materials that require fingerprint resistance. Examples of the decorative board include melamine, unsaturated polyester, diallyl phthalate, and acrylic decorative board. It is particularly preferable to use a melamine decorative board that is frequently used for furniture and building materials.

The method for forming the coating film on the substrate surface is not particularly limited. For example, brush coating, spray coating, dipping (dip coating), roll coating, gravure coating, micro gravure coating, flow coating, curtain coating, knife coating, spin coating, table coating, sheet coating, single wafer coating, die coating, bar coating It can be selected from ordinary coating methods such as reverse coating and cap coating. When a film is formed by such a coating method, a film having a large area can be easily obtained as compared with the gas phase method, and the film can be formed at a high speed.
In the film formation of the present invention, for example, after coating, a dense cured film can be formed simply by natural drying or forced drying at room temperature or at a temperature of 150 ° C. or lower for 30 minutes to 2 hours. The thickness of the coating may be any thickness as long as mechanical adhesion with the substrate can be maintained.

  The composite material of the present invention can be used for any application that requires resistance to fingerprint adhesion. For example, office furniture, kitchen building materials, sanitary products such as bathtubs and wash basins, exterior wall building materials, various optical parts such as lenses and filters, home appliances, window glass for automobiles, trains, airplanes, headlamp covers, utility poles It can be used as a coating film for preventing paper sticker for telephones and telephone boxes, and for water repellency, antifouling, oil stains, and oil and fat adhesion prevention.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. The coating film which is a typical example of the present invention will be described below.

[Examples 1 to 5]
The coating solution was prepared by adding 20.8 g of tetraethoxysilane and 2.6 g of decyltrimethoxysilane to 46.1 g of ethanol and stirring, then adding 19.8 g of water and 0.03 g of hydrochloric acid and stirring for 3 days at room temperature. To prepare a base solution. Dilute the base solution with the same weight of ethanol, and 100 parts by weight of diluted base solution as shown in Table 1, 0.01 to 5.0 parts by weight of 7 nm hydrophilic silica fine particles (product name AEROSIL 380, manufacturer Nippon Aerosil) In addition, the mixture was stirred to prepare a coating solution, and Examples 1 to 5 were prepared.
A commercially available melamine decorative board having a size of 7.0 × 2.5 cm, thoroughly washed with alcohol, immersed in the coating solution prepared above, lifted at 1 mm / s, dip-coated, and heat dried at 80 ° C. The color difference, glossiness, water contact angle, and oleic acid contact angle were measured for each sample, and the results are shown in Table 1.

  The gloss of a coating film is defined as the ratio of direct reflection to diffuse reflection of the film. The glossiness was measured using a Horiba gloss checker IG-330. Color difference measurement was performed to quantify the change in the appearance of the melamine decorative board due to the coating film. The measurement was performed using a Konica Minolta colorimeter CR-13.

  The water contact angle was determined by using a contact angle meter (contact angle meter CA-DT, manufactured by Kyowa Interface Science Co., Ltd.) after 5 seconds after a 0.3 mg water droplet was deposited on the surface of the coating film. It was measured. The oleic acid contact angle was determined by measuring the contact angle 5 seconds after 0.3 mg of oleic acid droplets were deposited on the surface of the coating film (contact angle meter CA-DT, Kyowa Interface Science Co., Ltd.). ).

[Examples 6 to 9, Comparative Example 1]
A coating solution was prepared in the same manner as in Example 1 except that 7 nm silica fine particles were changed to 12 nm hydrophilic silica fine particles (product name AEROSIL 200, manufactured by Nippon Aerosil Co., Ltd.). . The coated sample was measured for color difference, gloss, water contact angle, and oleic acid contact angle. The amount of silica added and the results are shown in Table 2.

[Examples 10-13, Comparative Examples 2-3]
A coating solution was prepared in the same manner as in Example 1 except that 7 nm silica fine particles were changed to 20 nm hydrophilic silica fine particles (product name AEROSIL 90, manufactured by Nippon Aerosil Co., Ltd.). . The coated sample was measured for color difference, glossiness, water contact angle, and oleic acid contact angle. The amount of silica added and the results are shown in Table 3. At the same time, the color difference and glossiness of the coating solution (Comparative Example 3) to which no silica fine particles were added were also measured.

According to Examples 1 to 13, by adding a slight amount of silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm, the glossiness of the coating film is 8 or less and the color difference is less than 4.6. It was possible to form a coating film in which the attached fingerprint was inconspicuous. Comparative Examples 1 and 2 had a color difference of 4.6 or more, and Comparative Example 3 was a coating film in which the hydrophilic fine particle silica was not added and the attached fingerprint was somewhat conspicuous.
Furthermore, it is considered that there is no problem with the anti-fingerprint adhesion evaluation by the film creator. However, when the oleic acid contact angle is 36 degrees or less, the oleic acid partially penetrates from the film surface, Even after wiping, some traces of wiping remained.

(Sensory test)
Next, 10 general persons who were not involved in film formation were selected as evaluators, and the following sensory test was performed. The evaluator was conducted without informing the sample type or content prescription.
For Examples 6, 10, and 11, as an evaluation of fingerprint resistance by 10 evaluators, the evaluators themselves touched with their fingers and conducted a sensory test of the difficulty of conspicuous fingerprints. The result was inconspicuous.
Next, the sensory test of the fingerprint resistance evaluation by ten evaluators was similarly conducted on Example 10 and Comparative Products A to C.
The results of the 10 evaluators are tabulated and summarized, and the determination results are shown in Table 4.

比較品Ａ：市販メラミン化粧板
比較品Ｂ：Ａのシボ形状変更メラミン化粧板
比較品Ｃ：市販耐指紋性メラミン化粧板
判定結果：○は、指紋が目立たない、もしくは気にならない。△は、比較品Ａより改善は見られものの、依然指紋が目立つ、もしくは気になる。

Comparative product A: Commercial melamine decorative board Comparative product B: A textured melamine decorative board of A Comparative product C: Commercial fingerprint-resistant melamine decorative board Judgment result: ○ is inconspicuous or unintentional. Δ shows improvement in comparison with comparative product A, but fingerprints are still noticeable or worrisome.

  According to the present invention, a coating film containing a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm is formed on the surface of the substrate, and the glossiness of the film is 8 or less and the color difference is less than 4.6. It was possible to provide a composite material on which a certain anti-fingerprint coating film was formed. The anti-fingerprint coating film has a high strength of the cured film itself and excellent scratch resistance, and includes a silicon compound-containing coating film containing a small amount of hydrophilic metal oxide fine particles having an average particle size of the order of nm. By doing so, the anti-fingerprint adhesion coating film can be formed easily and simply. Since the composite material on which the fingerprint-resistant coating film is formed does not stand out the attached fingerprints and hand stains, it can be used for various applications on the surface that comes in contact with humans.

Claims (7)

  A composite material comprising a substrate and a fingerprint-resistant coating film comprising a silicon compound and hydrophilic metal oxide fine particles having an average particle diameter of 1 to 100 nm formed on the surface of the substrate, wherein the coating film has a glossiness of 8 Hereinafter, a composite material on which a fingerprint-resistant coating film having a color difference of less than 4.6 is formed.   The composite material according to claim 1, wherein the silicon compound is at least one selected from alkoxysilane, alkylalkoxysilane, and chlorosilane.   The composite material according to claim 2, wherein the alkoxysilane is a tetraalkoxysilane and the alkylalkoxysilane is an alkyltrialkoxysilane.   The composite material according to claim 1, wherein the hydrophilic metal oxide fine particles are silica.   The composite material according to any one of claims 1 to 4, wherein the hydrophilic metal oxide fine particles are contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the silicon compound.   The composite material according to claim 1, wherein the substrate is a decorative board.   The composite material according to claim 6, wherein the decorative board is a melamine decorative board.