JP4403773B2 - Hydrophilized resin molded product - Google Patents

Description

  The present invention relates to a resin molded product having a hydrophilic film formed on its surface.

  A resin molded product having a hydrophilic film formed on its surface is suitably used for outdoor applications because it is difficult for dirt to adhere to it and it is easy to remove the dirt. For example, in Japanese Patent Application Laid-Open No. 7-299890 (Patent Document 1), a fluororesin film having an antifouling layer containing an inorganic hydrophilic colloid substance is bonded to the surface of a synthetic resin plate and used for an outdoor noise shielding plate. It has been proposed. JP-A-8-3478 (Patent Document 2) discloses that a coating layer having a contact angle with respect to water of 50 ° or less is formed on the surface of a transparent synthetic resin molded plate with an inorganic colloidal sol to form a road side wall plate. It has been proposed to use.

JP-A-7-299890 JP-A-8-3478

  However, since the conventional hydrophilic resin molded product does not necessarily have sufficient adhesion and scratch resistance of the hydrophilic film to the resin molded product, the hydrophilic film may be easily peeled off or easily damaged. Moreover, since the transparency of the hydrophilic film is not always sufficient, the function and appearance of the resin molded product may be deteriorated.

  Therefore, an object of the present invention is to provide a resin molded product suitable for outdoor use, in which a hydrophilic film having excellent adhesion and scratch resistance to a resin molded product and excellent transparency is formed.

  As a result of intensive studies, the present inventors have found that the above object can be achieved by forming a hydrophilic film on the surface of a resin molded article using a curable composition having a specific composition, and the present invention has been completed. It came to do.

  That is, according to the present invention, a hydrophilic film is formed on the surface of a resin molded product, and the hydrophilic film is composed of 40 to 60 parts by weight of a hydrolyzable organosilicon compound, chain-shaped inorganic compound fine particles, and needle-shaped inorganic particles. There is provided a hydrophilic resin molded article obtained by curing a composition containing 40 to 60 parts by weight of inorganic compound fine particles selected from compound fine particles.

  The hydrophilic resin molded product of the present invention has a hydrophilic film excellent in adhesion to the resin molded product and scratch resistance, and this hydrophilic film is also excellent in transparency.

  In the hydrophilic resin molded product of the present invention, a hydrophilic film is formed on the surface of a resin molded product serving as a base material (hereinafter, the resin molded product before forming the hydrophilic film may be simply referred to as a base material), This hydrophilic film imparts hydrophilicity and thus antifouling properties to the resin molded product. And this hydrophilic film | membrane hardens | cures the curable composition containing a hydrolysable organosilicon compound and inorganic compound microparticles | fine-particles.

  The thickness of the hydrophilic film is usually 10 to 1000 nm, preferably 50 to 500 nm. If the thickness of the hydrophilic film is too small, the hydrophilicity and strength may not be sufficient. If the thickness is too large, adhesion to the substrate and transparency may not be sufficient, and defects such as cracks may occur. Further, the hydrophilic film has a contact angle with water of usually 30 ° or less, preferably 20 ° or less.

  As the base material, for example, polymethyl methacrylate resin, polycarbonate resin, polystyrene, methyl methacrylate-styrene copolymer resin, acrylonitrile-styrene copolymer resin, triacetyl cellulose resin, flat plate shape, corrugated plate shape, The thing shape | molded in the plate shape which has a curvature, or what was shape | molded in the three-dimensional shape is mentioned. In particular, a molded product of polymethylmethacrylate resin is suitable for a substrate because of its excellent weather resistance.

  The substrate may have a flat surface or may have fine irregularities on the surface. In addition, another film such as a hard coat layer having scratch resistance may be formed on the surface.

  A hydrophilic film may be formed on the entire surface of the substrate, or may be partially formed. For example, if the substrate is a plate-like material, a hydrophilic film may be formed on both surfaces, or only on one surface.

  The hydrolyzable organosilicon compound that is one of the essential components of the curable composition for forming a hydrophilic film has at least one hydrolyzable group in the molecule, and the organic group is bonded to the silicon atom. Specifically, it can be represented by the following formula (I).

Si (R ¹ ) _q (R ² ) _4-q (I)

In the formula, R ¹ represents hydrogen or an inert monovalent organic group, R ² represents a hydrolyzable functional group, and q represents an integer of 0 to 3.

As the inactive monovalent organic group represented by R ¹ in formula (I), typically, an aryl group including an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, phenyl and the like Groups and the like. Examples of the hydrolyzable functional group represented by R ² include an alkoxy group having 1 to 5 carbon atoms including methoxy and ethoxy, an acyloxy group such as acetoxy and propionyloxy, a chlorine atom and a bromine atom. A halogen atom such as this, and a substituted silylamino group such as trimethylsilylamino. Well-known hydrolyzable organosilicon compounds are roughly classified into alkoxysilane compounds, halogenated silane compounds, acyloxysilane compounds, and silazane compounds. These organosilicon compounds are aryl groups, vinyl groups, allyl groups, (meth) acryloyloxy groups, epoxy groups, amino groups, mercapto groups, fluoroalkyls as part of R ¹ or R ² in the above formula (I). It may have a substituent such as a group.

  Specific hydrolyzable organosilicon compounds include, for example, halogenated silane compounds such as methyltrichlorosilane, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyl Dimethoxysilane, dimethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) ) -Γ-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxyp Pills methyldimethoxysilane, .gamma.-glycidoxypropyltrimethoxysilane, .gamma. alkoxysilane compounds such as glycidoxypropyl methyl dimethoxy silane, silazane compounds such as hexamethyldisilazane and the like. These may be used alone or in combination of two or more.

  Further, as the hydrolyzable organosilicon compound, a hydrolysis product obtained by hydrolyzing the above organosilicon compound may be used. Furthermore, you may use the multimer which condensed after the hydrolysis and became the oligomer or the polymer. These hydrolysis products and multimers can be produced by adding an acid such as hydrochloric acid, phosphoric acid or acetic acid, or a base such as sodium hydroxide or sodium acetate to the organosilicon compound.

  Examples of commercially available hydrolyzable organosilicon compounds include “Colcoat R”, “Colcoat 200”, “Colcoat N-103X”, “Ethyl silicate 28” manufactured by Colcoat Co., Ltd., and Mitsubishi Chemical Corporation. “MKC silicate MS-51”, “MKC silicate MS-56”, “MKC silicate MS-57”, “MKC silicate MS-56S”, “MKC silicate MSH1”, “MKC silicate MSH2”, and the like.

  The inorganic compound fine particles, which are another essential component of the curable composition, have a chain or needle shape, and a chain shape and a needle shape may be used in combination. By using the inorganic compound fine particles having such a shape, the transparency of the hydrophilic film can be enhanced, and the hydrophilicity can also be enhanced.

  Here, the chain shape means a shape like a chain in which a plurality of unit fine particles such as a spherical shape and a granular shape are connected. The chain length of the chain fine particles is usually 50 to 300 nm on average. The particle size of the unit fine particles constituting the chain fine particles is usually 5 to 30 nm on average, and the number is usually 5 to 10 on average per chain fine particle.

  The needle shape means an elongated shape like a needle, and the elongated shape is sometimes called a hair shape or a feather shape. The long diameter of the acicular fine particles, that is, the diameter corresponding to the length of the needle is usually 50 to 300 nm on average, and the short diameter of the acicular fine particles, that is, the diameter corresponding to the thickness of the needle is usually 5 to 30 nm on average. It is. Further, the ratio of the major axis / minor axis is usually 10/1 to 50/1 on average.

  The kind of the inorganic compound fine particles is selected as appropriate, but oxides such as silica, alumina, tin oxide, antimony oxide, and indium oxide, and composites such as tin-antimony composite oxide and indium-tin composite oxide. An oxide is preferably used. Of these, silica and alumina are more preferably used because of their excellent hydrophilicity and high strength. Two or more kinds of inorganic compound fine particles can be used as necessary.

  The inorganic compound fine particles may be used in the form of a solid or a sol dispersed in water or an organic solvent, but when the curable composition is configured as a paint as described below, It is preferable to use a sol. Examples of commercially available inorganic compound fine particles include “organosilica sol IPA-ST-UP” and “organosilica sol MIBK-ST-UP” sold by Nissan Chemical Industries, Ltd., if they are sol-like silica. Examples of the sol-like alumina include “alumina sol-100” and “alumina sol-200” sold by Nissan Chemical Industries, Ltd.

  The amount ratio of the hydrolyzable organosilicon compound and the inorganic compound fine particles in the curable composition is 40 to 60 parts by weight for the former and 40 to 60 parts by weight for the latter, with the total amount of both being 100 parts by weight. If the former exceeds 60 parts by weight and the latter is less than 40 parts by weight, the hydrophilic film may not be sufficiently transparent and hydrophilic. On the other hand, if the former is less than 40 parts by weight and the latter is more than 60 parts by weight, the adhesion of the hydrophilic film to the substrate may not be sufficient, and the scratch resistance may not be sufficient.

  The curable composition can contain a curable compound other than the hydrolyzed organosilicon compound, if necessary. Examples of such curable compounds include cationic polymerizable compounds such as epoxy compounds, oxetane compounds and vinyl ether compounds, and radical polymerizable compounds such as (meth) acrylate compounds, (meth) acrylamide compounds, maleimide compounds, and styrene derivatives. Etc. The amount of the curable compound used is usually 100 parts by weight or less with respect to 100 parts by weight of the hydrolyzable organosilicon compound, and the total amount of the curable compound, hydrolyzable organosilicon compound and inorganic compound fine particles is 100. It is usually about 10 to 20 parts by weight with respect to parts by weight.

  In order to apply the curable composition on the substrate, it is necessary to configure the composition as a paint. The paint usually contains a solvent in addition to the curable compound and the inorganic compound fine particles.

  The solvent is used to adjust the concentration and viscosity of the paint, the film thickness after curing, and the like. The solvent to be used may be appropriately selected. For example, alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, 2-butanol, isobutanol and tert-butanol, 2-ethoxyethanol, 2-butoxyethanol , Alkoxy alcohols such as 3-methoxypropanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, ketols such as diacetone alcohol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, Examples thereof include aromatic hydrocarbons such as toluene and xylene, and esters such as ethyl acetate and butyl acetate. The amount of the solvent used is appropriately selected depending on the material, shape, coating method, film thickness of the target film, etc. of the resin molded product, but is usually the total amount of hydrolyzable organosilicon compound and inorganic compound fine particles. The amount is about 20 to 10,000 parts by weight with respect to 100 parts by weight.

  In particular, by using dioxane and / or tetrahydrofuran as the solvent, the adhesion of the hydrophilic film to the resin molded article substrate can be further improved. The amount of dioxane and / or tetrahydrofuran used is preferably 5% by weight or more from the viewpoint of the adhesion of the hydrophilic film, based on the total amount of the paint, and 50% by weight or less from the viewpoint of the appearance of the product. Is preferred.

  The paint may contain a curing catalyst such as an acid, an alkali, an organometallic compound, or a metal ion in order to promote curing of the hydrolyzable organosilicon compound. Moreover, when another curable compound is contained, the initiator corresponding to it is added suitably. For example, when a cationically polymerizable compound is included, a cationic polymerization initiator such as an onium salt such as a diazonium salt, a sulfonium salt, or an iodonium salt is added. When a radically polymerizable compound is included, benzyl, benzophenone And radical polymerization initiators such as thioxanthones, benzyldimethylketals, α-hydroxyalkylphenones, hydroxyketones, aminoalkylphenones, and acylphosphine oxides.

  Moreover, you may make a coating material contain various additives, such as a stabilizer, antioxidant, a coloring agent, a leveling agent, and surfactant, as needed. In particular, silicone oil is preferably added because it not only improves leveling properties but also improves the slipperiness of the surface of the hydrophilic film and the surface hardness.

  Examples of silicone oils include dimethyl silicone oil, phenylmethyl silicone oil, alkyl / aralkyl-modified silicone oil, fluorosilicone oil, polyether-modified silicone oil, fatty acid ester-modified silicone oil, methyl hydrogen silicone oil, silanol group-containing silicone oil, Alkoxy group-containing silicone oil, phenol group-containing silicone oil, methacryl-modified silicone oil, amino-modified silicone oil, carboxylic acid-modified silicone oil, carbinol-modified silicone oil, epoxy-modified silicone oil, mercapto-modified silicone oil, fluorine-modified silicone oil, poly Ether-modified silicone oil, etc., may be used alone or in combination of two or more. Good. Examples of commercially available products include “BKY” series such as “BKY-306” and “BKY-333” sold by Big Chemie Japan.

  The amount of silicone oil added is usually 50 parts by weight based on 100 parts by weight of the total amount of the curable compound other than the hydrolyzable organosilicon compound, the inorganic compound fine particles, and the hydrolyzable organosilicon compound used as necessary. It is as follows. If it is added too much, the optical performance and strength of the hydrophilic film may be lowered.

  By applying the coating material as described above to the surface of the substrate, a curable coating film containing a hydrolyzable organosilicon compound and inorganic compound fine particles is formed. Examples of the coating method include a micro gravure coating method, a roll coating method, a dipping coating method, a flow coating method, a spin coating method, a die coating method, a cast transfer method, and a spray coating method.

  Subsequently, this coating film is cured by heating. The heating temperature is usually about 50 to 120 ° C., and the heating time is usually about 1 minute to 5 hours. When the coating film contains a solvent, the heat curing may be performed while the coating film contains the solvent, or after the solvent is volatilized. When the solvent is volatilized, it may be left at room temperature or may be dried by heating at about 30 to 100 ° C. The drying time is appropriately selected according to the material, shape, coating method, target hydrophilic film thickness, etc. of the substrate.

Moreover, when using curable compounds other than a hydrolysable organosilicon compound, you may use together the hardening method suitable for the curable compound. As one of such curing methods, an ultraviolet irradiation method can be mentioned. In this case, the ultraviolet irradiation time is usually about 0.1 to 60 seconds, the irradiation temperature is usually about 10 to 40 ° C., and the irradiation is performed. The energy is usually about 50 to 3000 mJ / cm ² . Either the hydrolyzable organosilicon compound or the other curable compound may be cured first.

  The hydrophilic film formed as described above has hydrophilicity and eventually antifouling properties, is excellent in adhesion to resin molded products and scratch resistance, and is also excellent in transparency. Furthermore, since it is excellent in durability, various performances are maintained over a long period of time. The hydrophilic resin molded product of the present invention having such a hydrophilic film can be used in various applications, and in particular, taking advantage of the above characteristics of the hydrophilic film, it is subject to dirt and impacts such as rain, wind, dust and dust. Suitable for easy outdoor use. Examples of such outdoor use include building materials such as signboards and carport roofs, window materials, and sound insulation walls for roads and railways.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. Moreover, the resin board with a hydrophilic film obtained in the Example was evaluated with the following method.

(1) Optical characteristics Using a transmittance meter (manufactured by Murakami Color Research Laboratory Co., Ltd., HR-100), total light transmittance (Tt) and haze (cloudiness value) are measured according to JIS K 7105. did.

(2) Hydrophilicity Using a contact angle meter (CA-X, manufactured by Kyowa Interface Science Co., Ltd.), the contact angle of water on the surface of the hydrophilic film was measured at 25 ° C.

(3) Adhesion A 1 mm sq. 100 grid pattern cut is made so as to penetrate the hydrophilic film with a cutter knife, cellophane tape (made by Nichiban Co., Ltd., 24 mm width) is pasted on this, and then this cellophane tape Was peeled off in the vertical direction and evaluated by the number of peels per 100 grids.

(4) Scratch resistance The tip of the eraser of the eraser wear tester (manufactured by Honko Seisakusho Co., Ltd.) is covered with gauze, and the surface of the hydrophilic film is reciprocated while applying a pressure of 49 N / cm ^2. Evaluation was based on the number of round trips until the scratch was confirmed.

Example 1
A sol containing 50 parts of a paint containing a hydrolyzable organosilicon compound at a concentration of 3% (manufactured by Colcoat Co., Ltd., “Colcoat N-103X”) and chain silica fine particles having an average chain length of 90 nm at a concentration of 15% ( 10 parts of “organosilica sol IPA-ST-UP” manufactured by Nissan Chemical Industries, Ltd., 22 parts of ethanol and 18 parts of dioxane were mixed to obtain hydrolyzable organosilicon compound / silica fine particles = 50 parts / 50 parts of hydrophilic paint were prepared. In this hydrophilic coating material, a polymethylmethacrylate resin extruded plate (“SUMIPEX E” manufactured by Sumitomo Chemical Co., Ltd.) is immersed as a base material, and dip-coated at a pulling speed of 60 cm / min. Heating was performed at 80 ° C. for 30 minutes to prepare a resin plate with a hydrophilic film. The evaluation results are shown in Table 1.

Comparative Example 1
A sol containing 30 parts of a paint containing a hydrolyzable organosilicon compound at a concentration of 3% (manufactured by Colcoat Co., Ltd., “Colcoat N-103X”) and chain silica fine particles having an average chain length of 90 nm at a concentration of 15%. 14 parts of “organosilica sol IPA-ST-UP” manufactured by Nissan Chemical Industries, Ltd.), 38 parts of ethanol, and 18 parts of dioxane were mixed and hydrolyzable organosilicon compound / silica fine particles = 30 parts / 70 parts of hydrophilic paint were prepared. Using this hydrophilic paint, a resin plate with a hydrophilic film was produced in the same manner as in Example 1. The evaluation results are shown in Table 1. Since the amount of silica fine particles exceeded the provisions of the present invention, the adhesion was poor.

Comparative Example 2
A sol containing 70 parts of a paint containing a hydrolyzable organosilicon compound at a concentration of 3% (manufactured by Colcoat Co., Ltd., “Colcoat N-103X”) and chain silica fine particles having an average chain length of 90 nm at a concentration of 15%. 6 parts of “organosilica sol IPA-ST-UP” manufactured by Nissan Chemical Industries, Ltd., 6 parts of ethanol and 18 parts of dioxane were mixed to obtain hydrolyzable organosilicon compound / silica fine particles = 70 parts / 30 parts of hydrophilic paint were prepared. Using this hydrophilic paint, a resin plate with a hydrophilic film was produced in the same manner as in Example 1. The evaluation results are shown in Table 1. Since the amount of the silica fine particles was less than that of the present invention, the haze was high and the transparency was poor.

Comparative Example 3
A sol (Nissan) containing 50 parts of a paint containing a hydrolyzable organosilicon compound at a concentration of 3% (manufactured by Colcoat Co., Ltd., “Colcoat N-103X”) and spherical silica fine particles having an average particle diameter of 15 nm at a concentration of 30% 5 parts of "organosilica sol IPA-ST" manufactured by Chemical Industry Co., Ltd., 27 parts of ethanol, and 18 parts of dioxane were mixed and hydrolyzable organosilicon compound / silica fine particles = 50 parts / 50 parts. A hydrophilic paint was prepared. Using this hydrophilic paint, a resin plate with a hydrophilic film was produced in the same manner as in Example 1. The evaluation results are shown in Table 1. Since no silica or fine particles were used as the silica fine particles, the haze was high and the transparency was poor.

(Durability test)
The durability test of the resin plate with a hydrophilic film obtained in Example 1 was performed with a sunshine weatherometer under the conditions of a black panel temperature of 63 ° C., a shower of 18 minutes / 120 minutes, and an irradiation time of 1000 hours. Even after the test, no change in appearance was observed, and transparency was maintained. Moreover, the contact angle with respect to water was also 10 degrees or less, and hydrophilicity was maintained.

Claims (3)

A hydrophilic film is formed on the surface of the polymethyl methacrylate resin molded product (except when the photocatalyst layer is coated), and the hydrophilic film is a hydrolyzable organosilicon compound [wherein general formula (1)

(In the formula, R ¹ represents either an alkyl group or an aryl group having at least one amino group. R ² and R ³ each represent an alkyl group having 1 to 3 carbon atoms, and R ² and R ³ represent They may be the same or different from each other, and n represents an integer of 1 to 3.)
The composition containing 40 to 60 parts by weight of silica particles and 40 to 60 parts by weight of silica fine particles selected from chain-like silica fine particles and needle-like silica fine particles is cured. A hydrophilic resin molded product characterized by that. The hydrophilic resin molded product according to claim 1, wherein the use is for outdoor use. A composition for forming a hydrophilic film on the surface of a polymethylmethacrylate resin molded product (except when the photocatalyst layer is coated), which is a hydrolyzable organosilicon compound [wherein general formula (1 )

(In the formula, R ¹ represents either an alkyl group or an aryl group having at least one amino group. R ² and R ³ each represent an alkyl group having 1 to 3 carbon atoms, and R ² and R ³ represent They may be the same or different from each other, and n represents an integer of 1 to 3.)
The case where it is a silane derivative represented by this is excluded. 40 to 60 parts by weight and 40 to 60 parts by weight of silica fine particles selected from chain-like silica fine particles and needle-like silica fine particles.