JPH0432710B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a chemical-resistant matte paint finishing method that is applied to the interior of a clean room that needs to be kept in a clean state. [Conventional technology] Clean rooms, such as rooms where various operations such as extremely precise electronic equipment are carried out, rooms where various biochemical technologies that have been attracting attention in recent years, sterilization rooms, operating rooms, etc. In order to improve the working environment based on psychological factors such as Usually has a matte coating. In addition, in order to maintain these rooms in a clean state, chemical cleaning and the like are periodically performed for the purpose of removing dust, mold, etc., and sterilizing them.
For example, walls are acid-washed with a nitric acid aqueous solution to remove mold and sterilize, and then oxidized and sterilized with a hypochlorite-produced soda aqueous solution. Furthermore, the matte paints applied to indoor wall materials such as concrete, aluminum, galvanized steel, and stainless steel are blended with matte materials, such as colloidal silica or resin powders such as polyethylene powder and fluororesin powder. The resulting light scattering creates a matte effect. [Problems to be Solved by the Invention] However, in matte paints containing these matting agents, the matting agents, such as colloidal silica, have poor alkali resistance and are dissolved by the agents, leaving voids in the coating film. In addition, resin powder has a low interfacial tension on its surface, which makes it difficult for paint to wet the binder resin, and voids may occur on the surface of the resin powder due to shrinkage of the binder resin during the process of forming a film. Therefore, when cleaning the surface of a matte paint film with chemicals, the chemicals pass through the voids and reach the surface of the base material, resulting in various problems such as corrosion of the base material or peeling of the paint film. The dot was hot. [Means for Solving the Problems] In view of the above-mentioned conventional techniques, it is an object of the present invention to provide a matte coating finishing method that is excellent in chemical resistance, long-term durability, and the like. That is, the present invention provides chemical resistance for a clean room, which is characterized by providing a glossy paint layer with high binder resin content and chemical resistance under a matte paint layer containing a matting agent. The present invention relates to a matte coating finishing method. According to the method of the present invention, even if the matte material is dissolved by a chemical or the like and voids are formed, the dense coating layer of the underlying glossy paint can still block the impregnating chemicals. , so that protection of the substrate is achieved. The present invention will be explained in more detail below. First, the glossy paint used in the present invention is
As mentioned above, it is necessary to block the impregnation of chemicals etc. through the matte paint film and to prevent the material from being immersed in the chemicals etc. Therefore, the binder resin content is increased (preferably, the binder resin content is 60% by weight or more in the solid content of the paint) and the usual pigment content is reduced, so that a dense film can be formed, and the binder resin itself Therefore, it is necessary to use a material with excellent chemical resistance. Examples of such binder resins include epoxy resins, silicone resins, acrylic resins, and fluorine resins. In particular, in the present invention, the "hydroxyl group-containing fluorine-containing copolymer" described below has not only chemical resistance but also extremely low oxygen permeability and moisture permeability, excellent UV resistance, etc.
Therefore, it is suitable from the viewpoint of excellent durability of the coating film and protection of the base material. Furthermore, as a specific example of the copolymer, a hydroxyl group-containing fluorine-containing copolymer containing fluoroolefin and cyclohexyl vinyl ether as constituent components is desirable, and in particular, a copolymer described in JP-A No. 57-34107 The combination sufficiently has the various performances described above,
Furthermore, since it can be cured at room temperature or by baking at a low temperature, it can be used very suitably. To explain more specifically, the hydroxyl group-containing fluorine-containing copolymer, which is a binder resin that can be suitably used in the present invention, contains fluoroolefin, cyclohexyl vinyl ether, alkyl vinyl ether, and hydroxyalkyl vinyl ether as essential constituents of 40 to 60% each. Mol%, 5
~45 mol%, 5-45 mol% and 3-15 mol%, preferably 45-55 mol%, 10-30 respectively
The content is 10 to 35 mol% and 5 to 13 mol%. In the above, an excessively low fluoroolefin content is not only unfavorable from the viewpoint of UV resistance, but also tends to cause problems in production. Also, those with too high fluoroolefin content,
There are difficulties in manufacturing. On the other hand, if the cyclohexyl vinyl ether content is too low, the hardness of the coating film will decrease, and if the alkyl vinyl ether content is too low, the flexibility will decrease, so both are not preferred. Furthermore, it is particularly important that the composition contains hydroxylalkyl vinyl ether in a proportion within the above range from the viewpoint of improving curability without impairing various useful properties as a paint base. In other words, if the hydroxyl alkyl vinyl ether content is too high, the solubility of the copolymer will change and it will only dissolve in certain substances such as alcohols, which will only limit its applicability as a solution-type paint base. This is not preferable because it reduces the flexibility of the cured coating film. In addition, if the content is too low, the effect of improving curability will be lost,
This leads to a decrease in the chemical resistance of the cured coating film. As the fluoroolefin as a raw material for the fluorine-containing copolymer, it is preferable to use perhaloolefin, particularly chlorotrifluoroethylene or tetrafluoroethylene. Further, as alkyl vinyl ethers, those containing a linear or branched alkyl group having 2 to 8 carbon atoms,
In particular, it is preferable to use an alkyl group having 2 to 4 carbon atoms. The fluorine-containing copolymer may contain comonomers other than the above four essential components in an amount not exceeding 30 mol %. Such comonomers include olefins such as ethylene, propylene, and isobutylene, haloolefins such as vinyl chloride and vinylidene chloride, unsaturated carboxylic acid esters such as methyl methacrylate, vinyl acetate, vinyl n-butyrate, etc. Examples include unsaturated carboxylic acids such as vinyl carboxylates, fumaric acid, maleic acid, acrylic acid, and methacrylic acid. The fluorine-containing copolymer preferably has an intrinsic viscosity of about 0.05 to 2.0 dl/g, particularly about 0.07 to 0.8 dl/g, as measured in an uncured state in tetrahydrofuran at 30°C. The above fluorine-containing copolymer is prepared by adding a polymerization initiator such as a water-soluble initiator or an oil-soluble initiator or ionizing radiation to a monomer mixture of a predetermined ratio in the presence or absence of a polymerization medium. It is produced by causing a copolymerization reaction by applying a polymerization initiation source. Examples of the hydroxyl group-containing fluorine-containing copolymers include Lumiflon LF100, Lumiflon LF200, Lumiflon LF300, and Lumiflon LF400 (all trade names manufactured by Asahi Glass Co., Ltd.), which are commercially available and easily available. Further, as the curing agent for the fluorine-containing copolymer,
In the case of a room temperature curing type, a polyvalent isocyanate having two or more isocyanate groups in one molecule is suitable. The polyvalent isocyanate includes aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylene diisocyanate, hydrogenated xylylene diisocyanate, or biuret forms and dimers thereof.
Typical examples include reaction products of trimers or excess of these isocyanate compounds with low molecular weight polyols such as ethylene glycol, glycerin, trimethylolpropane, and pentaerythritol. Needless to say, in the case of a room-temperature curing type, the curing agent becomes a two-component paint, which is mixed with the hydroxyl group-containing fluorine-containing copolymer solution as the main ingredient immediately before coating. In addition, in the case of the bake-hardening type, blocked isocyanate is obtained by masking the polyvalent isocyanate with a masking agent such as phenols, alcohols, oximes, lactams, amines, or amides;
Representative examples include condensation products of amino compounds such as melamine, urea, benzoguanamine, and acetoguanamine with aldehyde compounds, or curing agents such as aminoplast resins in which the condensation products are further etherified with alcohols such as butanol. . In the present invention, the glossy paint includes other paint film-forming components, taking into account covering of base material edges, ease of applying film thickness on vertical surfaces, painting workability, etc.
40% by weight of pigment or filler in total solids of paint
Below, it is particularly desirable to blend 5 to 30% by weight. (However, if metal pigments are used,
As the pigment or filler, coloring pigments and extender pigments that have excellent chemical resistance and are commonly used as pigments for paints can be used. Further, in the present invention, it is desirable to contain flake powder or conductive pigment as the pigment or filler. The flaky powder is arranged parallel to the surface of the base material in the coating film, suppressing excess corrosive substances (factors) such as moisture and chemicals, and exerting the function of protecting the base material. Examples of the above-mentioned flame-like powder include glass flakes, mica flakes, etc.
A size of 0.5 to 7μ and a size of 30 to 300μ is suitable.
Further, it is desirable that the amount is about 5 to 35% by weight based on the total solid content of the paint. In addition, the thickness of the flaky powder is 0.5μ
If it is smaller, the strength is weak and it cannot be used in practice. On the other hand, if it is thicker than 7μ, it tends to be difficult to align parallel to the base material surface. Further, if the size is smaller than 30μ, it tends to be difficult to arrange parallel to the surface of the base material, and if it is larger than 300μ, it is not preferable because it will impede painting workability such as spray painting. Further, the use of conductive pigments has the function of preventing dust, dirt, etc. from being electrostatically attracted to the coating surface. Such conductive pigments include metal powders such as stainless steel powder, aluminum powder, copper powder, and nickel powder, carbon powder, etc., and are blended in a proportion of about 10 to 40% by weight of the total solid content of the paint. is desirable. Further, it is preferable to use flake-like metal powder because it can simultaneously impart electrical conductivity to the coating film and suppress the permeation of corrosive factors. Incidentally, when a conductive pigment is blended into a matte paint, which will be described later, it is not necessarily necessary to blend it into a glossy paint. The glossy paint used in the present invention contains other solvents and, if necessary, various additives and modifiers. Examples of the solvent include aromatic hydrocarbons such as xylene and toluene, alcohols such as n-butanol, esters such as butyl acetate, ketones such as methyl isobutyl ketone, glycol ethers such as ethyl cellosolve, etc. Various commercially available thinners can also be used. As the matte paint used in the present invention, commercially available matte paints containing a matte agent can be used as they are. That is, colloidal silica with a particle size of about 0.01 to 0.5μ, or polyethylene powder, polystyrene powder, polyfluorocarbon powder, etc. with a particle size of about 5 to
Contains 50μ resin powder as a matting agent. In addition, in the case of colloidal silica, it is about 2 to 10% by weight of the total solid content of the paint, and in the case of resin powder, it is about 5% by weight.
It contains ~20% by weight. The matte paint also contains a binder resin (preferably the same as the glossy paint that forms the lower layer coating),
It consists of a solvent, coloring pigments, extender pigments, the conductive pigments, various additives, and modifiers as required. In the present invention, the coating film can be formed by a conventional method. In other words, the surface of wall materials made of materials such as concrete, aluminum, galvanized steel, and stainless steel is treated as necessary, such as surface treatment and primer application, and then glossy paint is applied by spraying, flow coating, etc.
Apply using a roller or other means to a dry film thickness of approximately 10 to 100 microns. Then, a matte paint is applied in the same manner to a dry film thickness of about 10 to 100 μm.
Depending on the type of glossy paint and matte paint, a cured film can be formed by drying at room temperature, forced drying, or baking drying. You can overpaint and select them as you like. <Effects of the Invention> Since the coating film obtained as a result of carrying out the method of the present invention has a matte paint coating applied to the outer surface, it has a matte paint finish. In addition, since a glossy paint film layer with chemical resistance is provided below the matte paint film, the outer surface of the paint film can be cleaned with chemicals, and even if the chemicals impregnate through the matte paint film, the lower layer will remain intact. A glossy paint film blocks the penetration of corrosive factors into the base material. In particular, when the aforementioned hydroxyl group-containing fluorine-containing copolymer is used as a resin binder for glossy paints, not only chemical resistance but also oxygen permeability and moisture permeability are extremely low, and therefore the ability to protect the base material is even higher. improves. Therefore, it must be kept clean at all times.
It is clear that the finishing method of the present invention is preferable in clean rooms where cleaning with chemicals is frequently performed. Hereinafter, the details of the present invention will be explained with reference to Examples. Note that "parts" and "%" are expressed on a weight basis. Example 1 A glossy paint consisting of the following formulation was spray-painted on an aluminum partition material that had undergone chromic acid chemical conversion treatment,
Baking was performed at 160°C for 30 minutes to obtain a glossy coating film with a thickness of 40μ. Next, a matte paint consisting of the following composition was spray-painted on the coating film, and baked at 160℃ for 30 minutes to determine the film thickness.
A 30μ matte coating was obtained. The obtained test plate was subjected to a chemical resistance test, and the results were as shown in Table 1, and it was found to be suitable for use in a clean room. <Glossy paint> Fluorine-containing copolymer solution (Note 1) 87.2 parts Blocked isocyanate solution (Note 2) 12.8 parts Titanium oxide 30.0 parts Organic solvent 12.3 parts Additives 0.4 parts <Matte paint> Fluorine-containing copolymer Solution (Note 1) 87.2 parts Blocked isocyanate solution (Note 2) 12.8 parts Titanium oxide 31.6 parts Colloidal silica 4.3 parts Organic solvent 43.2 parts Additives 0.4 parts (Note 1) "Lumiflon LC200D" [Product name manufactured by Asahi Glass Co., Ltd.; NV50% , hydroxyl value (solid content) 57〕 (Note 2) NV80%, NCO equivalent 1152 Comparative example 1 The matte paint used in Example 1 was applied to aluminum partitioning material using a two-coat, two-bake method, and the total film thickness was A matte coating of 70μ was obtained. When the obtained test plate was subjected to a chemical resistance test, the results were as shown in Table 1, and the chemical resistance was poor and it was unsuitable for use in a clean room.

[Table] Example 2 Concrete wall material coated with epoxy sealer, thickness approximately 1-7μ, particle size 48-325 mesh 70%,
Unsaturated polyester paint containing 34% of the solid content of glass flakes, 25% below 325 mesh and 5% above 48 mesh [Regi Lining #10S]
"Gray" (trade name, manufactured by Dainippon Toyo Co., Ltd.), resin content of 65% of the solid content of the paint] was applied and dried to obtain a glossy coating film with a film thickness of 100μ. Next, a fluorine-containing copolymer solution ["Lumiflon LF200" (trade name, manufactured by Asahi Glass Co., Ltd.),
A matte paint consisting of 60% NV, 63 parts of hydroxyl value (solid content), 12 parts of titanium oxide, 4 parts of colloidal silica, 6 parts of isocyanate resin, and 15 parts of organic solvent is applied and dried to form a glossy film with a thickness of 40μ. An eraser film was obtained. When the same test as in Example 1 was conducted, no abnormalities such as blistering or peeling were observed in the coating film. Example 3 49 parts of fluorine-containing copolymer solution "Lumiflon LF200", 8 parts of blocked isocyanate solution (NV80%, NCO equivalent 359), and additives were added to a stainless steel plate (SUS#304-HL) for wall material of a laser beam irradiation chamber. A clear coating consisting of 1.5 parts of organic solvent and 41.5 parts of organic solvent was applied and baked to obtain a glossy coating film with a thickness of 10 μm. Next, the fluorine-containing copolymer solution 43 is applied onto the coating film.
parts, 7 parts of the blocked isocyanate solution, 5 parts of colloidal silica, 2 parts of phthalocyanine green.
A matte paint consisting of 1 part of additive, 42 parts of organic solvent was applied, and a matte paint film with a baked film thickness of 15 μm was obtained. The obtained test plate was subjected to a hot water immersion test (40℃, 120℃
time), 5% caustic soda immersion test (20℃, 120 hours), 5% hypochlorous acid immersion test (20℃, 120 hours)
As a result, no abnormalities such as blistering or peeling were observed in the coating film. Comparative Example 2 In Example 3, a matte paint was applied in a 2-coat, 2-bake method without applying a glossy coating to obtain a matte coating with a total thickness of 25μ, and a similar test was conducted. The paint film peeled off in the test as well. Example 4 A two-component acrylic-urethane resin paint containing 35% nickel powder in the paint solids (64% resin in the paint solids) was applied to concrete wall material coated with an epoxy sealer and dried. and film thickness 30μ
A glossy coating film was obtained. Next, on the coating film, carbon black and colloidal silica were added at 3.8% each based on the solid content of the coating.
A matte paint similar to the two-component acrylic-urethane resin paint containing 7.5% and excluding nickel powder was applied and dried to obtain a matte paint film with a film thickness of 15 μm. When the obtained test plate was subjected to the same test as in Example 1, no abnormality such as blistering or peeling was observed in the coating film. In addition, regarding dust adhesion, comparison was made with a matte coating obtained by applying the above-mentioned matte coating excluding carbon black to a total film thickness of 45μ without applying a glossy coating. It was extremely excellent. (Even after being left indoors for one month, almost no dust was observed.)

Claims (1)

[Scope of Claims] 1. A matte paint finish for a clean room, characterized in that a glossy paint film layer with high binder resin content and chemical resistance is provided below the paint film containing a matte agent. Method. 2. The matte coating finishing method for a clean room according to claim 1, wherein the binder resin of the glossy coating is composed of a hydroxyl group-containing fluorine-containing copolymer and its curing agent. 3 Claim 1, characterized in that the glossy paint contains flaky powder having chemical resistance.
Clean room matte painting finishing method described in section. 4. The matte painting finishing method for a clean room according to claim 1, wherein the glossy paint or the matte paint contains a conductive pigment.