JP3971243B2 - Manufacturing method of coated material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a coated product. More specifically, the present invention relates to a method for producing a coated product capable of forming a film imparting desired properties such as water repellency and oil repellency. Typical examples of the coated material include electric appliances such as washing machines, refrigerators, dehumidifiers, hot plates, automobiles, bicycles, motorcycles, trains, and other vehicle bodies, ship hulls, building parts, and the like.
[0002]
[Prior art]
As a method for surface-treating the base material, a coupling agent, an alkali agent or the like is added to the suspension of the coating agent, the base material is immersed in the liquid phase, and then the base material is subjected to heat treatment. There has been proposed a method (liquid phase coating method) for coating a surface of a coating material with a coating agent. In particular, this method is generally employed when a silicone compound or a fluorine compound is coated on the surface of a substrate for the purpose of imparting water repellency and / or oil repellency to the substrate.
[0003]
However, this method requires a step of removing the water or organic solvent forming the liquid phase by heat treatment or the like, and has a drawback that the manufacturing process becomes complicated and the manufacturing cost increases. Further, in the conventional liquid phase coating method, a substrate having a narrow gap such as a substrate having a complicated shape such as a hole in a porous material, a winding pipe, a surface with severe irregularities, or a stacked plate-like material May not be applied uniformly.
[0004]
[Problems to be solved by the invention]
The present invention is a coating that forms a film on a substrate having a complicated shape or a substrate having a narrow gap in a simple manufacturing process without using an organic solvent harmful to the human body or performing heat treatment. It is an object to provide a method for manufacturing a product.
[0005]
[Means for Solving the Problems]
The present invention is a coating method in which a base material and a silicone polymer compound are brought into contact with each other in the presence of a supercritical fluid in a container, and then the silicone polymer compound is applied to the substrate by reducing the pressure in the container. The silicone-based polymer compound has a formula (I): at the terminal and / or side chain of the molecular chain of the organopolysiloxane.
[Chemical formula 1]
(Wherein R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 10 carbon atoms, X ⁻ represents a counter ion of a quaternary ammonium salt) or Formula (II):
[Chemical formula 2]
(Wherein R ¹ , R ² and X ⁻ are the same as above)
Via a group represented by formula (III):
[Chemical formula 3]
(In the formula, R ³ is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and n is 2) Or 3)
The molecular chain of poly (N-acylalkylenimine) consisting of repeating units represented by the formula is bonded, and the weight ratio of the molecular chain of poly (N-acylalkylenimine) to the molecular chain of organopolysiloxane is 1 It is related with the manufacturing method which is a silicone type high molecular compound which is / 20-20 / 1 .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
The supercritical fluid is a fluid having a pressure higher than the critical temperature (Tc) and higher than the critical pressure (Pc), and has a property that the density is suddenly changed by a slight pressure change. Therefore, if the pressure of the supercritical fluid slightly exceeding the critical pressure (Pc) and critical temperature (Tc) is increased, the density of the gas phase increases rapidly, so that the solubility of the solute in the fluid exceeding the critical pressure is increased. Increases rapidly. On the contrary, when the pressure of the supercritical fluid is decreased, the solubility of the solute in the fluid can be drastically lowered, so that the solute and the supercritical fluid can be separated only by a decompression operation. In addition, supercritical fluids have a density close to that of a liquid and have a low viscosity close to that of a gas and a relatively large diffusivity. Therefore, supercritical fluids are excellent for substrates with complex shapes and substrates with narrow gaps. Exhibits high permeability.
[0007]
Specific examples of the raw material of the supercritical fluid include ketones such as carbon dioxide and acetone, hydrocarbons such as water, alcohol, benzene, toluene and xylene. Among these, carbon dioxide is preferable because it is non-toxic and inexpensive and has a critical temperature of 304.2 K and is not high temperature, so that energy can be saved.
[0008]
The temperature when supercritical carbon dioxide is used and the supercritical carbon dioxide is expanded under reduced pressure is preferably 308.15 to 373.15K, more preferably 308.15, from the viewpoint of efficiently performing the reduced pressure expansion of supercritical carbon dioxide. It is ~ 333.15K. Further, the initial pressure of supercritical carbon dioxide when performing decompression expansion is preferably 7.2 to 50 MPa, and more preferably 10 to 40 MPa, in order to efficiently perform decompression expansion of supercritical carbon dioxide.
[0009]
The method for reducing the pressure is not particularly limited, but the temperature is lowered due to the adiabatic expansion action at the time of pressure reduction, but it is preferable that the temperature does not fall below the critical temperature of carbon dioxide of 304.2K.
[0010]
As described above, when a supercritical fluid is used, the operation of applying the organic compound to the substrate becomes easy.
[0011]
The use of supercritical carbon dioxide is preferable because the solubility of the solute can be made higher than the use of liquefied carbon dioxide.
[0012]
As a method of coating a substrate with an organic compound in a container using a supercritical fluid, the substrate is placed in the supercritical fluid in a container at a predetermined temperature and pressure, and the organic compound is dissolved and dispersed. After that, the exhaust valve provided in the container is opened, the inside of the container is decompressed, heated as necessary, and the supercritical fluid is volatilized and removed to form a film of the organic compound on the substrate surface. It is done. According to this method, the base material coated with the organic compound can be obtained in the container. Further, when supercritical carbon dioxide is used, it is not necessary to perform heat treatment or the like.
[0013]
The time required to reduce the pressure in the container to atmospheric pressure is preferably 2 seconds to 120 minutes, more preferably 5 seconds to 60 minutes, from the viewpoint of controlling the film thickness of the coating.
[0014]
The method of reducing the pressure in the container can reduce the pressure reduction speed in contrast to the time required for reducing the pressure to atmospheric pressure in the method of ejecting from the nozzle to the outside of the container to 1 second or less. It has the advantage that the separation rate of solute from carbon can be reduced. Therefore, the organic compound tends to adhere uniformly to the substrate.
[0015]
In addition, since the carbon dioxide in which the organic compound is dissolved / dispersed is easily present in the gap between the base materials, it is likely to be separated from the carbon dioxide, so that a thin base material with a uniform coating thickness can be obtained. Therefore, it is preferable to reduce the pressure in the container from the viewpoint of controlling the film thickness of the coating.
[0016]
As the substrate, any of inorganic substances and organic substances that are substantially insoluble in the supercritical fluid can be used.
[0017]
Examples of the inorganic substance include metals such as stainless steel, platinum, gold, silver, copper, and aluminum, and non-metallic inorganic substances such as glass and ceramic, which are used alone or in combination of two or more. be able to.
[0018]
Examples of the organic material include tangible materials such as plastic, fiber, diamond, and the like, and these can be used alone or in admixture of two or more.
[0019]
One of the features of the present invention is that an organic compound can be applied to a substrate having a regular or irregular shape. Examples of the shape of the substrate include a plate shape, a spherical shape, and a rod shape. Further, the substrate may have a complicated shape such as having pores. When the substrate has a plate-like or rod-like shape, the minimum side is preferably 1 mm or more, and more preferably 1 cm or more. When the substrate has a spherical shape, the diameter is preferably 1 mm or more, and more preferably 1 cm or more.
[0020]
The organic compound may be any organic compound that is generally used as a surface treatment agent and that dissolves and disperses in a supercritical fluid. Representative examples of organic compounds include silicone compounds, fluorine compounds, chitosan, Nε-lauroyl-L-lysine and the like. Among organic compounds, a polymer compound can be preferably used.
[0021]
As described above, the polymer compound may be any one that dissolves and disperses in the supercritical fluid. Among organic polymer compounds, general polymer compounds such as acrylic resin, polyethylene, and polystyrene are difficult to dissolve in supercritical carbon dioxide. On the other hand, fluorine-based polymer compounds and silicone-based polymer compounds generally have a low intermolecular force and have a property of being easily dissolved and dispersed in supercritical carbon dioxide. Accordingly, when using a fluorine-based polymer compound and / or a silicone-based polymer compound, it is not necessary to use a solvent, or only a small amount needs to be used. Therefore, the organic compound can be applied to the substrate without considering the remaining solvent.
[0022]
The fluorine-based polymer compound may be a polymer compound having a fluorine atom. The weight composition ratio of fluorine atoms in the fluorine-based polymer compound is 9 to 80% by weight, preferably 20 to 70% by weight, and more preferably 40 to 65% by weight. Among the fluorine-based polymer compounds, a (meth) acrylic acid ester polymer having a fluoroalkyl group or a perfluoro group, and a (meth) acrylic acid ester-long chain alkyl (meth) having a fluoroalkyl group or a perfluoro group Acrylate copolymers are preferred.
[0023]
Further, as a fluorine-based polymer compound, a homopolymer of (meth) acrylate having a perfluoroalkyl group having 4 or more carbon atoms, a polyfluoroalkyl group or a perfluoropolyether group, and this compound and a carbon number of 8 to 22 A copolymer with an (meth) acrylate having an alkyl group is most preferred.
[0024]
The silicone polymer compound is not particularly limited as long as it is dissolved or dispersed in a supercritical fluid alone or in a mixture of a supercritical fluid and a solvent. Among silicone polymers, methylpolysiloxane, dimethylpolysiloxane, cyclic dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, cyclic methylhydrogenpolysiloxane, dimethylsiloxane methyl (polyoxyethylene) siloxane A copolymer, a dimethylsiloxane / methyl (polyoxypropylene) siloxane copolymer, a polyether-modified silicone, a methylstyryl-modified silicone, an alkyl-modified silicone, a higher fatty acid ester-modified silicone, a higher alkoxy-modified silicone, and the like are preferable.
[0025]
Among the silicone-based polymer compounds, the end of the molecular chain and / or the side chain of the organopolysiloxane is represented by the formula (I):
[0026]
[Formula 4]
[0027]
Wherein R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 10 carbon atoms, X ⁻ represents a counter ion of a quaternary ammonium salt, and Cl ^-, Br ^- halogen ion or CH ₃ SO _4, such as _{^{-, CH 3 CH 2 SO 4}} - sulfuric ester ions, etc.) or formula (II):
[0028]
[Chemical formula 5]
[0029]
(Wherein R ¹ , R ² and X ⁻ are the same as above)
Through the group represented by formula (III):
[0030]
[Chemical 6]
[0031]
Wherein R ³ is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, and n is 2 Or 3)
The molecular chain of poly (N-acylalkylenimine) consisting of repeating units represented by the formula is bonded, and the weight ratio of the molecular chain of poly (N-acylalkylenimine) to the molecular chain of organopolysiloxane is 1 A silicone polymer compound having a weight average molecular weight of 500 to 500,000 is particularly preferable. For example, poly (R ¹ and R ² in formula (I) are each a hydrogen atom, X ⁻ is CH ₃ CH ₂ SO ₄ ⁻ , R ³ in formula (III) is CH ₂ CH ₃ , and n is 2. N-propanoylethyleneimine) graft-dimethylsiloxane / γ-aminopropylmethylsiloxane copolymer.
[0032]
The concentration of the organic compound dissolved or dispersed in the supercritical fluid is not particularly limited, but is 0.1 to 90% by weight, preferably 1 to 30% by weight.
[0033]
When the organic compound is difficult to dissolve or disperse in the supercritical fluid, the organic compound can be dissolved or dispersed in the supercritical fluid by mixing the solvent with the supercritical fluid.
[0034]
As the solvent, a polar solvent is preferable. Among polar solvents, alcohol and water which are considered to be almost harmless to the human body are preferable. As alcohol, methanol, ethanol, and 1-propanol are preferable, and ethanol is more preferable.
[0035]
As described above, the method of the present invention does not require heat treatment after application as in the conventional liquid phase coating method, and therefore the number of processing steps can be reduced, so that the method is very excellent in operability. is there.
Through the above operation, the organic compound can be applied to the substrate.
[0036]
The container used in the present invention is not limited to the shape and size, and any container that can withstand the temperature and pressure to be used may be used. The container may have an exhaust mechanism such as a valve for performing a decompression operation. Further, in order to dissolve and disperse the organic compound in the supercritical fluid, it is preferable to have a stirring mechanism in the container. Typical examples of the container include an autoclave and a pressure cell.
[0037]
【Example】
Example 1
The apparatus shown in FIG. 1 was used. In an autoclave 10 (content volume 500 mL: manufactured by AKICO), 2.0 g of poly (N-propanoylethyleneimine) graft-dimethylpolysiloxane / γ-aminopropylmethylsiloxane copolymer (solid) and substrate A [thickness A stainless steel plate (SUS304) having a length of 2 mm, a width of 40 mm, and a length of 150 mm was folded in half so as to form a gap of 0.3 mm, and the longitudinal side surfaces thereof were welded.
[0038]
After filling, the dust in the carbon dioxide is removed from the cylinder 1 through the filter 2, and then the carbon dioxide is condensed in the condenser 3 through which the refrigerant controlled to −5 ° C. is passed from the cooler 5, and then the pump head is cooled. The pressure was boosted by the boosting pump 4 that was made. The pressure at the time of pressure increase was measured by the pressure gauge 6a. In order to ensure safety, a safety valve 7a was disposed below the pressure gauge 6a. The pressure was adjusted with a pressure holding valve V-1.
[0039]
Carbon dioxide was preheated to a predetermined temperature through the preheater 8 and then introduced into the autoclave 10 to which the safety valve 7b was attached via the valves V-2 and V-3. The temperature in the autoclave 10 was adjusted by the temperature controller 13 using the cartridge heater 12, and the temperature and pressure in the autoclave 10 were adjusted to a temperature of 333.15 K and a pressure of 20 MPa by the thermometer 11 and the pressure gauge 6b, respectively.
[0040]
Under this condition, the stirrer 9 was rotated and dissolved and dispersed for 0.5 hour.
The exhaust valve V-3 was opened gradually, the exhaust line 14 (inner diameter 2.5 mm) was exhausted, and the pressure was reduced for 10 minutes. Although the temperature inside the autoclave 10 is lowered due to the adiabatic expansion action at the time of decompression, the pressure inside the cell was reduced so as not to become 313.15K or less. In addition, the heater 15 was heated to prevent the exhaust line from freezing.
[0041]
After the container pressure in the autoclave 10 was reduced to atmospheric pressure, the substrate A was taken out from the autoclave 10, and both the surface and the gap of the substrate A were translucently whitened. When this base material A was taken out after being immersed in water, it was confirmed that the whitened part was water-repellent. From this, it can be seen that the poly (N-propanoylethyleneimine) graft-dimethylpolysiloxane / γ-aminopropylmethylsiloxane copolymer can be applied uniformly.
[0042]
Example 2
In Example 1, instead of the base material A, the base material B [aluminum plate having a thickness of 2 mm, a width of 40 mm, and a length of 150 mm was folded in half so that a gap of 0.3 mm was formed, and the side surface in the longitudinal direction was The base material B was applied in the same manner as in Example 1 except that the welded one was used. As a result, both the surface and the gap of the base material B were translucently whitened. When this base material B was taken out after being immersed in water, it was confirmed that the whitened part was water-repellent. From this, it can be seen that the poly (N-propanoylethyleneimine) graft-dimethylpolysiloxane / γ-aminopropylmethylsiloxane copolymer can be applied uniformly.
[0043]
Example 3
In Example 1, instead of the base material A, the base material C [a copper plate having a thickness of 2 mm, a width of 40 mm, and a length of 150 mm is folded in half so that a gap of 0.3 mm is formed, and the side surface in the longitudinal direction is welded. The substrate C was applied in the same manner as in Example 1 except that the above was used. As a result, both the surface and the gap of the substrate C were translucently whitened. When this base material C was taken out after being immersed in water, it was confirmed that the whitened part was water-repellent. From this, it can be seen that the poly (N-propanoylethyleneimine) graft-dimethylpolysiloxane / γ-aminopropylmethylsiloxane copolymer can be applied uniformly.
[0044]
Example 4 (Example 4 is a reference example)
In Example 1, instead of poly (N-propanoylethyleneimine) graft-dimethylpolysiloxane / γ-aminopropylmethylsiloxane copolymer, stearyl methacrylate / 2- (perfluorooctyl) ethyl methacrylate copolymer (polymerization) Application to the substrate A was carried out in the same manner as in Example 1 except that the ratio 1: 9) was used.
[0045]
Both the surface of the obtained base material A and the gap were whitened translucently. When this base material A was taken out after being immersed in water, it was confirmed that the whitened part was water-repellent. From this, it can be seen that both the surface and the gap of the obtained base material are uniformly coated with the stearyl methacrylate · 2- (perfluorooctyl) ethyl methacrylate copolymer.
[0046]
From the above results, according to the method in each example, a substrate having a complicated shape or a narrow gap can be easily formed by a simple operation without using an organic solvent harmful to the human body or performing a heat treatment. It turns out that an organic compound can be apply | coated to the base material which has.
[0047]
【The invention's effect】
According to the method of the present invention, an organic compound can be easily applied to a substrate having a complicated shape or a substrate having a narrow gap by a simple operation without using an organic solvent harmful to the human body. it can.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing one embodiment of an apparatus used in each embodiment of the present invention.
[Explanation of symbols]
1 Cylinder 2 Filter 3 Condenser 4 Booster Pump 5 Cooler
6a Pressure gauge
6b pressure gauge
7a Safety valve
7b Safety valve 8 Preheater 9 Stirrer
10 Autoclave
11 Thermometer
12 Cartridge heater
13 Temperature controller
14 Exhaust line
15 heater
V-1 Holding valve
V-2 valve
V-3 Exhaust valve

Claims (1)

A method for producing a coated product in which a silicone polymer compound is applied to a substrate by bringing the substrate into contact with the silicone polymer compound in the presence of a supercritical fluid in the container and then reducing the pressure in the container. The silicone-based polymer compound has the formula (I): at the terminal and / or side chain of the molecular chain of the organopolysiloxane.
(Wherein R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 10 carbon atoms, X ⁻ represents a counter ion of a quaternary ammonium salt) or Formula (II):
(Wherein R ¹ , R ² and X ⁻ are the same as above)
Via a group represented by formula (III):
(In the formula, R ³ is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and n is 2) Or 3)
The molecular chain of poly (N-acylalkylenimine) consisting of repeating units represented by the formula is bonded, and the weight ratio of the molecular chain of poly (N-acylalkylenimine) to the molecular chain of organopolysiloxane is 1 The manufacturing method which is a silicone type high molecular compound which is / 20-20 / 1 .