JPH0576511B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an antifogging resin. More specifically, the present invention relates to an antifogging resin made of a polymer of a specific (meth)acrylamide derivative. Prior art and its problems: Utilizing their transparency, inorganic glass, transparent ceramics, and plastic materials can be used to create various products such as window glass for houses, window glass for trains, trains, and other passenger vehicles, mirror surfaces, eyeglass lenses, and goggles. It is used for a purpose. However, one major drawback of these various products is that when they are used in high temperature, high humidity, or high temperature or humidity locations, water vapor condenses finely on their surfaces, resulting in cloudy surfaces. Particularly when the surfaces of window glass, eyeglass lenses, mirror surfaces, etc. become cloudy, various problems arise. Conventionally, various attempts have been made to solve this problem, including various surfactants, hydroxyl-substituted (meth)acrylate polymers,
One or two types of (meth)acrylate polymers substituted with the side chains of polyalkylene glycols, various silicon compounds such as dimethylsiloxane, etc.
Methods of applying or spraying a combination of more than one species are being considered. However, none of these methods is yet fully satisfactory, and various improvements have been attempted. The cause differs depending on the method used, and various factors can be considered. Means for solving the problem: The present inventors focused on the fact that most of the cloudiness is caused by the contact of the cold glass surface with warm air. As a result of intensive efforts to develop a temperature-sensitive water-absorbing resin in which the temperature decreases as the temperature increases, the inventors discovered that it functions as an excellent anti-fogging resin and arrived at the present invention. That is, the present invention relates to the general formula () or the general formula represented by the general formula ().

[Chemical formula] (In the above formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a methyl group, or an ethyl group, and R ₃ represents a methyl group, an ethyl group, or a propyl group.) General formula

[Chemical formula] (In the above formula, R ₁ is a hydrogen atom or a methyl group, and A is (――
CH ₂ ) _o -- and n is 4 to 6 or (-CH ₂ ) ₂ --O(
---
CH ₂ ) ₂ -- represents. ) An antifogging resin made of an N-alkyl- or N-alkylene-substituted (meth)acrylamide alone or a copolymer, or a copolymer with other copolymerizable monomers. Specific N-alkyl or N-alkylene substituted (meth)acrylamides of the present invention include, for example, N-n-propylacrylamide (polymer cloud point 32°C), N-n-propylmethacrylamide, N-isopropylacrylamide (polymer cloud point 29°C), N-isopropylmethacrylamide, N-ethylacrylamide, N,N-
Diethylacrylamide, N-ethylmethacrylamide, N,N-dimethylacrylamide, N,
Examples include N-dimethylmethacrylamide, N-acryloylpyrrolidine (polymer cloud point: 51 DEG C.), N-methacryloylpyrrolidine, N-acryloylpiperidine, N-methacryloylpiperidine, N-acryloylmorpholine, and the like. In addition, monomers that can be copolymerized with the above monomers include hydrophilic monomers, ionic monomers, lipophilic monomers, etc., and one or more of these monomers are applicable. can. Specifically, as a hydrophilic monomer,
For example, acrylamide, methacrylamide, N
- Methylacrylamide, diacetone acrylamide, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, various methoxypolyethylene glycol methacrylates, various methoxypolyethylene glycol acrylates, N-vinyl-2-pyrrolidone, etc. You can also use vinyl acetate,
Glycidyl methacrylate or the like can also be introduced by copolymerization and hydrolyzed to impart hydrophilicity. Examples of the ionic monomer include acrylic acid, methacrylic acid, vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, styrenesulfonic acid, 2-acrylamido-2-phenylpropanesulfonic acid, and 2-acrylamide-2-
Acids such as methyl-propanesulfonic acid and their salts, N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, N,N-dimethylaminoethyl acrylate, N,N-dimethylaminopropylmethacrylamide, N , N-dimethylaminopropylacrylamide, and salts thereof. It is also possible to introduce various acrylates, methacrylates, acrylamide, methacrylamide, acrylonitrile, etc. by copolymerization and hydrolyze them to impart ionicity. Examples of lipophilic monomers include N-n-butylacrylamide, N-butylmethacrylamide, N-tert.-butylacrylamide, N-
tert.-butyl methacrylamide, N-n-hexyl acrylamide, N-n-hexyl methacrylamide, N-n-octylacrylamide, N-
N-alkyl (meth)acrylamide derivatives such as n-octylmethacrylamide, N-tert.-octylacrylamide, N-n-dodecylmethacrylamide, N-n-dodecylmethacrylamide,
N,N-diglycidyl acrylamide, N,N-
Diglycidyl methacrylamide, N-(4-glycidoxybutyl)acrylamide, N-(4-glycidoxybutyl)methacrylamide, N-(5
-glycidoxypentyl)acrylamide, N-
N-(w-glycidoxyalkyl)(meth)acrylamide derivatives such as (6-glycidoxyhexyl)acrylamide, ethyl acrylate, methyl methacrylate, butyl methacrylate, butyl acrylate, lauryl acrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, etc. (meth)acrylate derivatives of, acrylonitrile, methacrylonitrile, vinyl acetate,
Vinyl chloride, olefins such as ethylene, propylene, butene, styrene, α-methylstyrene,
Examples include butadiene, isoprene, etc. Next, as a specific method for producing an antifogging resin by polymerizing the above-mentioned monomers, (1) polymerizing in an aqueous solution,
(2) Polymerization in a solvent and after polymerization, the polymer solution remains as it is or the solvent is distilled off or the polymer is not dissolved. A method of obtaining a polymer by operations such as adding it to a poor solvent and precipitating the polymer, (3) A method of obtaining a polymer as a polymer emulsion by emulsion polymerization, (4) A method of obtaining a polymer as a polymer particle by suspension polymerization. (5) A method in which the monomer is directly polymerized without being diluted with a solvent to obtain a polymer block, among which methods (1), (2), and (3) are preferred. . In the method (2), a wide variety of solvents can be used during polymerization since (meth)acrylamide and its N-substituted derivatives have very good compatibility with various solvents. Specifically, alcohols such as methanol and ethanol, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, ketones such as acetone, and amides such as N,N-dimethylformamide and N,N-dimethylacetamide. aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as chloroform and methylene dichloride,
dimethyl sulfoxide, N-methylpyrrolidone,
Examples include chain glycols such as diglyme and tetraglyme, and basic solvents such as pyridine. At this time, the polymerization can be initiated by heating alone, but better results are usually obtained by using a polymerization initiator. The polymerization initiator is not limited as long as it has the ability to initiate radical polymerization, and includes, for example, inorganic peroxides, organic peroxides, combinations of these peroxides and reducing agents, and azo compounds. Specifically, ammonium persulfate, potassium persulfate, hydrogen peroxide, tert
-Butyl peroxide, benzoyl peroxide, cumene hydroxy peroxide, tert-butyl peroxy-2-ethylhexanoate, butyl perbenzoate, etc., and supergentants to be combined with these include sulfites, hydrogen sulfites, Examples include salts with low ionic valences such as iron, copper, and cobalt, organic amines such as aniline, and pergenosaccharides such as aldoses and ketoses. Examples of azo compounds include azobisisobutyronitrile, 2,2-azobis-2
-amidinopropane hydrochloride, 2,2-azobis-
2,4-dimethylvaleronitrile, 4,4-azobis-4-cyanovaleic acid, etc. can be used. It is also possible to use two or more of the above polymerization initiators in combination. In this case, the amount of the polymerization initiator to be added is sufficient to be within the normally adopted quantitative range, for example, from 0.01 to 5% by weight, preferably from 0.05 to 2% by weight, based on the monomer. Among the polymers thus obtained, those obtained in solid form can be dissolved in any solvent to provide a solution, or can be pulverized to provide a powder. At this time, the solution may be an aqueous solution or a solution of an organic solvent as described above. As described above, the resin of the present invention has good compatibility with various solvents and also has excellent adhesiveness to transparent substrates such as glass. Furthermore, if the resin is water-soluble, there will be a problem with the sustainability of its antifogging properties, so it can also be used after being made insoluble in water. There are two ways to make these polymers insoluble in water: during polymerization and after polymerization. A method of copolymerizing a crosslinkable monomer having the above with the above-mentioned (meth)acrylamide derivative, a method of copolymerizing an N-alkoxymethyl (meth)acrylamide derivative, and a method of copolymerizing the above-mentioned lipophilic monomer to produce a (meth)acrylamide derivative. a method of copolymerizing with,
A method of polymerizing in bulk, a method of heat-treating the polymer, a method of reacting a hydroxyl group or an amino group, etc. with a polyfunctional compound such as epichlorohydrin to insolubilize the polymer by reacting it with a polyfunctional compound, Furthermore, copolymerization with monomers substituted with substituents having active hydrogen such as carboxy groups, sulfonic acid groups, hydroxyl groups, etc., or formation of complexes with polymers substituted with these substituents. , a method of insolubilization, etc. can be adopted. More specifically, in the first method, as a crosslinking monomer, for example, N,N'-methylenebisacrylamide, N,N-diallylacrylamide, triacryl formal, N,N-diacrylolimide, N,N-dimethacryloyl imide, ethylene glycol acrylate, ethylene glycol dimethacrylate, various polyethylene glycol diacrylates, various polyethylene glycol dimethacrylates, propylene glycol diacrylate, propylene glycol dimethacrylate, various polypropylene glycol diacrylates, various polypropylene glycol dimethacrylates, 1,3-butylene Glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Trimethylolethane triacrylate, tetramethylolmethanetetramethacrylate, tetramethylolmethane triacrylate, divinylbenzene, diallyl phthalate, etc. can be used. In this case, since the polymer is insoluble in the solvent, a specific method is to bring the monomer into contact with the object to be antifogged and polymerize on the object. The N-alkoxymethyl (meth)acrylamide derivative in the second method is N
- Also includes hydroxymethyl (meth)acrylamide, such as N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-n-butoxymethyl (meth)acrylamide, N- tert.-butoxymethyl (meth)acrylamide, etc. can be used. In this case, the polymer may be polymerized on the object to be antifogged, or the polymer may be applied onto the object. In this case, insolubilization can be achieved more effectively by heat treatment at a temperature of 60 to 250°C. (Meta) of lipophilic monomers in the third method
Although the ratio to the acrylamide derivative varies depending on the combination of the (meth)acrylamide derivative and the lipophilic monomer and cannot be definitively determined, it is generally 1% or more, preferably 3% or more, and 75% or less. In this case as well, the two methods described above can be employed, but coating with a polymer is simpler and preferable. As for the fourth method of bulk polymerization, it is better to hold the monomer on the surface of the substrate to be antifogged without diluting it with a solvent and then polymerize it, followed by heat treatment at a temperature of 60 to 250°C. Can be effectively insolubilized. In the fifth method, which is a method of heat treating a polymer, the heating conditions vary depending on the polymer and are not uniform, but are generally 60 to 250°C, preferably
The base material to be antifogged which has been integrated with a polymer by a method such as monomer polymerization or polymer coating may be heated at a temperature of 80 to 200°C. In this case, when applying the polymer solution, drying or distillation of the solvent may be performed concurrently with heat treatment. In the sixth method, a method in which a polyfunctional compound such as epichlorohydrin is reacted to crosslink and insoluble, it is necessary to introduce a hydroxyl group or an amino group into the polymer in advance. Amino groups and carboxyl groups can be easily introduced by copolymerization, but in the case of hydroxyl groups, they can be introduced by copolymerization with hydroxyethyl methacrylate, isopropenylphenol, etc., or by copolymerization with vinyl acetate, glycidyl methacrylate, etc., and then with a base. Another method is to introduce hydroxyl groups by saponification with a chemical substance.
Next, the above-mentioned polymer is integrated with the object to be antifogged, and a polyfunctional compound such as epichlorohydrin is added and reacted to make it insolubilized. The seventh method is copolymerization with the above-mentioned monomers having active hydrogen, complexing with copolymers of these monomers, replacing active hydrogen in the polymer with ammonium ions, etc., and first mixing. This is a method in which the active hydrogen is activated by adding acid to form a complex and become insolubilized.The complex may be formed on the object to be antifogged, or the formed complex may be exposed to water. Some polymers are insoluble but soluble in organic solvents, so the polymer solution may be applied to the object to be antifogged and integrated. When the resin produced by the above method is an aqueous solution, it may become cloudy at a certain temperature when it is heated.On the other hand, in the case of a water-retaining gel made insoluble in water, it can be maintained at a certain temperature as shown in the reference example. The amount of water changes, and the lower the temperature, the greater the amount of water retained. As described above, the resin of the present invention absorbs more water at lower temperatures and has the property of releasing water as the temperature increases, making it ideal as an antifogging resin. This is because fogging occurs on glass surfaces in most cases when a cold surface comes into contact with warm air, etc., and the problem is the water absorption ability at low temperatures, and the resin of the present invention is exactly that. It can be said that it meets such requirements. Another advantage is that when the temperature rises, the water it retains is released, so its water absorption capacity at low temperatures does not become saturated, and it is always ready to absorb water at low temperatures. In a specific embodiment, when the resin of the present invention is a solution of water or other solvent, or an emulsion solution, it is directly applied to the surface of a transparent substrate such as a glass surface using a piece of cloth, a piece of paper, a sponge, etc. However, it may also be aerosolized using a propellant such as liquefied petroleum gas, fluorohydrocarbon, isobutane, dimethyl ether, or the like, or sprayed using a container equipped with a spray device. Thereafter, if necessary, heat treatment can be performed to remove the solvent and make it insolubilized. In addition, when polymerizing a monomer on the surface of a substrate, the monomer is present on the surface by immersion in the monomer or by condensing monomer vapor on the surface under vacuum, and then exposed to light such as ultraviolet rays. Alternatively, it may be polymerized by irradiation with gamma rays or heat treatment. At this time, a polymerization initiator may be dissolved in the monomer. The thickness of the resin on the base surface is from several microns to several millimeters, and depends on the amount of coating liquid and its concentration, etc.
Thickness can be controlled. In addition, additives such as various surfactants, fragrances, rust preventives, colorants, deodorants, preservatives, abrasives, builders, etc. can be used together with the resin of the present invention. Function: As mentioned above, the antifogging resin of the present invention (1) has a higher water absorption power at lower temperatures and releases water when heated, so the water absorption ability at low temperatures does not become saturated and can absorb water at any time at low temperatures. It is in. (2) Since the resin can be dissolved in a variety of solvents and a variety of insolubilization methods can be employed, anti-fog processing can be performed using a variety of methods. (3) The resin has effects such as excellent adhesion to transparent substrates such as glass. The present invention will be further explained below with reference to Examples. Example 1 75 g of N-acryloylpyrrolidine was dissolved in 655 g of distilled water, cooled to 10°C, transferred to a stainless steel distiller bottle, and nitrogen gas was added to the solution using a ball filter at a flow rate of 0.5 min. Bubbled for a minute. Then, a solution prepared by dissolving 0.4 g of ammonium persulfate in 10 g of distilled water and a solution prepared by dissolving 0.17 g of sodium bisulfite in 10 g of distilled water were added simultaneously to the aqueous solution, and the aqueous solution was polymerized adiabatically.
A 10% aqueous polymer solution of N-acryloylpyrrolidine was obtained. A glass plate whose surface has been thoroughly degreased and cleaned is immersed in the polymer aqueous solution, then pulled out and heated to 60°C.
After drying under vacuum, it was heat-treated at 125°C overnight. The surface of the glass plate after heat treatment remained transparent, and when brought into contact with water vapor, the surface of the glass plate did not become cloudy, became uniformly wet, and remained transparent. This phenomenon did not change even after repeating the wet state and dry state five times. Comparative Example 1 When a glass plate whose surface had been thoroughly degreased and cleaned was brought into contact with water vapor, fine water droplets adhered to the surface of the glass plate, causing clouding on the surface of the glass plate. Examples 2 to 21 A 10% aqueous polymer solution having the copolymer composition shown in Table 1 was obtained in the same manner as in Example 1. A glass plate heat-treated with the polymer was obtained using the polymer aqueous solution in the same manner as in Example 1, and the transparency of the glass plate and the antifogging property of the surface when the glass plate was brought into contact with water vapor were evaluated. Evaluate transparency and table-
The results shown in 1 were obtained. Example 22 6 ml of a 1% polymer aqueous solution of ammonium acrylate was added to 14 ml of a 1% polymer aqueous solution of N-acryloylpyrrolidine to make a uniform aqueous solution, and 2 ml of 1N hydrochloric acid aqueous solution was added. At the same time as the addition, the formation of a complex was confirmed at the interface with the aqueous hydrochloric acid solution, and the complex was separated as a white film. After washing the composite with distilled water, it was dried and ground to obtain a powder. A glass plate treated with the composite was obtained in the same manner as in Example 1 using a 10% solution of the powder in N,N-dimethylformamide. The surface of the glass plate was transparent, and when brought into contact with water vapor, the surface of the glass plate became uniformly wet, did not become cloudy, and remained transparent. Example 23

【table】

[Table] A composite was obtained in the same manner as in Example 22 using a 1% aqueous solution of Nn-propylacrylamide. A glass plate treated with the composite was obtained in the same manner as in Example 22 using the composite. The surface of the glass plate was transparent, and when brought into contact with water vapor, the surface of the glass plate became uniformly wet, did not become cloudy, and remained transparent. Example 24 9 g of N-acryloylpyrrolidine and 1 part of acrylonitrile in 100 ml of N,N-dimethylformamide
g and 0.164 g of azobisisobutyl were added and dissolved, and after purging the inside of the reactor with nitrogen gas, polymerization was carried out at 50° C. for 3 hours. After polymerization, pour the polymerization solution into ethyl ether to precipitate the polymer, and dry it separately.
A copolymer of N-acryloylpyrrolidine and acrylonitrile in a composition ratio of 90:10 was obtained. A glass plate treated with the copolymer was obtained in the same manner as in Example 1 using a 10% aqueous solution of the copolymer. The surface of the glass plate was transparent, and when it came into contact with water vapor, the surface of the glass plate became uniformly wet, did not become cloudy, and remained transparent. Example 25 N-n instead of N-acryloylpyrrolidine
-A 10% aqueous polymer solution of Nn-propylacrylamide was obtained in exactly the same manner as in Example 1 except that -propylacrylamide was used.
A glass plate heat-treated with the polymer was obtained in the same manner as in Example 1 using the polymer aqueous solution. The surface of the glass plate after heat treatment remained transparent, and when brought into contact with water vapor, the glass plate surface uniformly leaked without fogging and remained transparent. Example 26 A 10% aqueous polymer solution of N-isopropylacrylamide was obtained in exactly the same manner as in Example 1, except that N-isopropylacrylamide was used instead of N-acryloylpyrrolidine.
A glass plate heat-treated with the polymer was obtained in the same manner as in Example 1 using the polymer aqueous solution. The surface of the glass plate after heat treatment remained transparent, and when brought into contact with water vapor, the glass plate surface uniformly leaked without fogging and remained transparent. Example 27 10% N,N of N,N-diethylacrylamide
- Transfer the dimethylformamide solution to a Dewar bottle, replace the solution with nitrogen, add 1.5% azobisisobutyronitrile at 30°C, polymerize adiabatically, and make 10% of N,N-diethylacrylamide. % polymer solution was obtained. A glass plate heat-treated with the polymer was obtained in the same manner as in Example 1 using the polymer solution. The surface of the glass plate after heat treatment remained transparent, and when brought into contact with water vapor,
The surface of the glass plate uniformly leaked without fogging and remained transparent. Example 28 Example 1 except that N-acryloylmorpholine was used instead of N-acryloylpyrrolidine.
A 10% aqueous polymer solution of N-acryloylmorpholine was obtained in exactly the same manner as above. By the same method as in Example 1 using the polymer aqueous solution,
A glass plate heat-treated with the polymer was obtained. The surface of the glass plate after heat treatment remained transparent, and when brought into contact with water vapor, the surface of the glass plate uniformly leaked without fogging and remained transparent.

Claims (1)

[Claims] 1 [Formula] represented by general formula () or general formula () (In the above formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom, a methyl group or an ethyl group, and R ₃ is (Represents a methyl group, ethyl group or propyl group.) [Formula] (In the above formula, R ₁ is a hydrogen atom or a methyl group, and A is (-
OH ₂ ) _o -- and n is 4 to 6 or (-OH ₂ ) ₂ --O(
―
OH ₂ ) ₂ -- represents. ) Forming a resin film on a transparent substrate, consisting of a radical alone or a copolymer of N-alkyl or N-alkylene substituted (meth)acrylamide, or a radical copolymer with other copolymerizable monomers. A method for antifogging a transparent substrate.