JPS63317325A - Antifogging sheet and antifogging method - Google Patents

Abstract

PURPOSE:To obtain an antifogging sheet of glass, mirror or the like, by a method wherein a plastic, having a property capable of being bonded by water or alcohol without employing an adhesive agent except the base material of the sheet, is formed so as to have the form of sheet. CONSTITUTION:A plastic, having a property capable of being bonded by water or alcohol without employing an adhesive agent except the base mate rial of a sheet, is formed so as to have the form of sheet. The plastic, having a property capable of being bonded by water or alcohol, is a polymer solved into a photosensitive vinyl compound and cured thereafter, the polymer is methoxymethlated polyamide resin or urethane acrylate. The polymer, resolved in the photosensitive vinylate, is cured and formed so as to have the form of sheet, then, is bonded to an antifogging sheet by water and/or alcohol. The antifogging sheet, capable of being bonded and separated simply and leaving no trace of separation thereon, may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an anti-fog sheet for glass, mirrors, etc. and a method for preventing fog.

(b) Conventional technology Glass and mirrors have a low surface resistance value and a high thermal conductivity, so water vapor condenses on the surface and fogging often occurs.

For example, it is no exaggeration to say that bathroom mirrors are often cloudy. Therefore, when shaving or the like in the bath, the surface of the mirror must be constantly rinsed with water or coated with soapy water.

Furthermore, the inner surface of a car's windshield is also a part that often fogs up. In winter or during rainfall, when there is a large difference in temperature and humidity inside and outside the vehicle, the interior temperature is high and there is a lot of water vapor, but the outside temperature is low, so the windshield surface becomes colder than the interior temperature. Therefore, dew condenses on the inner surface of the windshield, causing fogging. In this case, the driver or the passenger in the front seat wipes the vehicle with a towel or the like.

The following methods can be used to prevent such fogging phenomenon.

(1) Prevent condensation.

That is, the surface temperature is raised to prevent cooling condensation from occurring on the surface. For this purpose, the temperature of the glass itself must be raised using a heater.

It is also possible that water molecules adhering to the surface are absorbed. This is because when molecules are absorbed, dew cannot form.

(2) Prevent diffuse reflection.

When dew condenses on the surface, the water droplets become minute particles and diffuse reflection, resulting in cloudiness. Therefore, if the particles are not made into fine particles but immediately wetted and the surface is made smooth, no clouding will occur.

Therefore, various ideas and inventions have been made to put into practice the above theory of preventing fogging.

The heating method is to provide a heater between the laminated glass sheets, such as a hot wire heater for the rear window of an automobile.

As a method of smoothing the surface and causing wetting on the entire surface without forming fine particles, there is a method of spraying an anti-fogging agent using a surfactant or the like.

Furthermore, as a method for immediately dropping or removing water molecules or very small water droplets without adhering to the surface, there is a method of subjecting the glass surface to a fluorine treatment, which makes the surface highly water-repellent.

(C) Problems that the invention aims to solve However, at present, all of them still have drawbacks such as being very expensive, difficult to install, and requiring spraying each time.
It is no exaggeration to say that there is no fundamental solution.

Therefore, there has been a strong demand among the glass industry and general consumers for a way to easily prevent fogging of glass and mirrors.

(d) Means to Solve the Problems In view of the above-mentioned current situation, the inventor of the present invention has completed the prevention sheet and prevention method of the present invention as a result of intensive research, and its characteristics are as follows. The point is that a plastic that can be bonded with water is formed into a sheet without using any adhesive other than the sheet base material.

Here, plastics that have the property of being able to be bonded with water or alcohol without using any adhesive other than the sheet base material are:
It has water-soluble functional groups such as hydroxyl groups in the carbon chain of the polymer, and although it does not completely dissolve in water, etc., only the surface layer dissolves or swells temporarily, and it can be mixed with glass by water, etc. A plastic that exhibits adhesive strength.

Examples include partially saponified polyvinyl alcohol and polyamide. Alternatively, a cured product of a mixture of a polymer and a vinyl compound as described below may be used.

Here, the high molecular weight polymer is a concept that refers to polymers, prepolymers, etc., which are dissolved singly or in combination in a photosensitive vinyl compound. Further, the polymer itself may also have photosensitivity.

In the inventor's experiments, polyamide resin, urethane acrylate, etc. were suitable, but the material is not limited thereto, and epoxy acrylate, etc. can also be used.

As an example of polyamide resin, N-methoxy-6-nylon showed good results. This is a nylon in which the hydrogen of the amide-bonded N atom of 6-nylon is replaced with a methoxymethyl group, and its structural formula is shown in (1). The amount of molten charcoal etc. varied depending on the degree of substitution, but it was possible to use charcoal substituted in a normal manner. The manufacturing method is 6.
-The simplest method is to add formaldehyde and methanol to nylon and heat it.

Urethane acrylate refers to a compound that has a urethane bond and also has an acrylate double bond.

According to the inventor's experiments, a polyester urethane acrylate whose structure is represented by the formula (If) is suitable.

Additionally, epoxy acrylates can also be used.

An example of this is shown in formula (III).

These high molecular weight polymers can be used not only alone but also in combination. This is particularly advantageous when a compound that cannot be dissolved in the photosensitive vinyl compound alone can be dissolved by mixing a plurality of them.

The term "photosensitive vinyl compound" is a concept that includes polymers, oligomers, prepolymers, etc. that have the property of photocuring, and may be a mixture of a plurality of them. Furthermore, it may contain commonly mixed substances such as a polymerization initiator and a sensitizer.

Structurally, it can be said that it is a molecule that has a functional group for photocuring, such as an acryloyl group, an ar-OCHCFI
0COCIL=CH2...(If) (However,
1. (ta, n, ρ are integers) Monomers having a lyle group or the like as a functional group were suitable. - derivatives of acrylic or methacrylic acid, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypolyethyl (meth)acrylate, dimethylaminoethyl ( Meta)
Acrylate, diethylaminoethyl (meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1.6
Hexanediol di(meth)acrylate, etc., such as hydroxyethyl methacrylate (HEMA), N
- Methylacrylamide is preferred. However, the material is not limited to these, and any material may be used as long as it has photocurability.

The photosensitive vinyl compounds may be used alone or in combination.

It is also useful to add a low molecular weight alcohol to the mixture of the high molecular weight polymer and photosensitive vinyl compound as described above. For example, ethanol, propatool, ethylene glycol, glycerin, sorbitol, etc. In the inventor's experiments, isopropatool was suitable.

Addition of these alcohols has the effect of enhancing the adhesive force due to water.

Any method may be used to form the film (including sheet form), but it is possible to form a mixture of a high molecular weight polymer and a photosensitive vinyl compound into a thin film, and then irradiate it with light or ultraviolet light or heat it. The method of hardening is simple. The thickness of this sheet itself is not limited, but from 40 to 1
Approximately OOμ was suitable.

The object to be prevented from fogging refers to an object to be prevented from fogging, and includes glass, a mirror, etc., and is not particularly limited.

Furthermore, the mixture of the present invention can be colored by mixing pigments or dyes. Coloring may be partial. In this way, you can easily decorate the mirror and change the atmosphere of your room or bathroom by changing the mirrors in various ways. When used in car windows, it also acts as a blind to reduce direct sunlight.

Furthermore, by printing on the sheet of the present invention, it is possible to further enhance the effect of the above-mentioned decoration or to give it an advertising effect. It can also be used as a label that easily adheres to glass.

Furthermore, it has properties not found in ordinary plastics, such as being able to be easily drawn and printed using water-based paints.

Next, how to use this anti-fogging sheet will be explained.

Water is applied to the anti-fogging sheet of the present invention, and the sheet is attached to glass. In addition, if it is not needed, it can be easily removed by applying water to the middle of the glass and peeling it off.

The most important features of the anti-fogging sheet of the present invention are that it can be easily applied with water and can be easily peeled off without leaving any traces.

Pasting can be done not only with water but also with alcohol. In particular, a mixture of low-molecular alcohol, such as propatool, and water was most suitable in terms of adhesive strength.

Furthermore, it is popular to attach a plastic film such as a polyester film to the film-like body of the present invention. In this method, the finished films may be glued together,
Adhesion may also be achieved by curing the mixture described above on a plastic film.

Applications of the anti-fogging sheet of the present invention include bathroom mirrors and glass, automobile windshields, eyeglasses, ordinary window glass, and show window glass.

The reason why the anti-fogging sheet of the present invention does not fog is not theoretically clear, but it can be inferred as follows.

(1) Since it is made of plastic, it has poor thermal conductivity and is inherently less prone to condensation.

(2) Low surface resistance value.

(3) Due to its molecular structure, water is easily absorbed.

Therefore, even under conditions where dew condensation occurs, the film absorbs moisture immediately, so it does not turn into minute water droplets but is adsorbed onto the entire sheet. Moreover, it is thought that the process of releasing the moisture again during drying is repeated.

(el Example [Example 1] After methoxymethylating 30% of the amide groups of the polyamide resin, 20 parts by weight of the polyamide resin was added to hydroxyethyl methacrylate.
)80ffi! 75 to 1 part, 5 parts by weight of isopropanol
The mixture was stirred and dissolved at a temperature of .degree. C., and 1 part by weight of benzoin ethyl ether was added to obtain a colorless and transparent resin liquid.

This material was placed on a glass plate covered with a polyester film, then covered with a polyester film, and then pressed with glass to make the film thicker. It was possible to make a cured resin sheet by exposing it to light at a distance for 3 minutes.

When I applied this film to a bathroom mirror using water, the adhesive strength was sufficient and it was easy to apply. The parts of the mirror that were not affixed were affected by the presence of steam, but the parts to which they were affixed did not become cloudy. Next, I applied water to the top edge and used my fingernail to peel off a portion of the glass and pulled it down, removing any unwanted residue from the glass.

[Example 2] 10 parts by weight of polyurethane acrylate (Polyurethane No. 109 manufactured by Kyowa Hakko ■) was dissolved in 5 parts by weight of hydroxyethyl methacrylate and 5 parts by weight of dimethylaminoethyl acrylate, and the solution was poured onto a glass. After forming into a thin film, it was cured in the same manner as in Example 1 to obtain a film.

This film was tested in a bathhouse in the same manner as in Example 1, and although the adhesive strength was inferior to that in Example 1, the desired effect was obtained.

Further, this film was attached to a mirror with a 50% aqueous solution of isopropanol, and the same experiment as above was conducted. In this case, the adhesiveness was better than in the above case.

ff) Effects of the Invention The use of the anti-fogging sheet of the present invention has the following great advantages.

It can be easily applied to fil &Ji''J with water, alcohol, or an aqueous solution of alcohol.

(2) When it is no longer needed, it can be easily peeled off by simply applying water.

(3) Since mirrors etc. do not fog up, when shaving or styling hair in a bathhouse, it is not necessary to take extra effort to remove the fog.

(4) It can also be attached to a part of a mirror, etc.

(5) If this film is printed, it can be used as a label for advertising in bathhouses, etc.

(6) It can be easily attached to glass bottles, etc., and it is also easy to peel off, so it is suitable as a medication label. (7) When attached to the window glass of a car, it prevents the inner surface from fogging, and it can be placed in front of or on the side of the driver. The view is unobstructed. This is very important for accident prevention.

(8) Using colored ones also prevents glare from sunlight or reflected light when driving.

(9) Photosensitive resins are generally acrylic-based, and these usually have high surface hardness (118 or higher on the pencil hardness scale) and are less prone to surface damage.

As mentioned above, this is a useful invention with many advantages.

Claims (1)

[Scope of Claims] 1. An anti-fogging sheet characterized in that it is formed into a sheet of plastic that can be bonded with water or alcohol without using any adhesive other than the sheet base material. 2. The anti-fogging sheet according to claim 1, wherein the plastic having the property of adhesion with water or alcohol is obtained by curing a high molecular weight polymer dissolved in a photosensitive vinyl compound. 3. The anti-fogging sheet according to claim 2, wherein the high molecular weight polymer is a methoxymethylated polyamide resin or urethane acrylate. 4. A high molecular weight polymer dissolved in a photosensitive vinyl compound is cured to form a film, and then water and/or
Or a method for preventing fogging, which is characterized by applying alcohol to the object to be prevented from fogging. 5. The anti-fogging device according to claim 4, wherein the high molecular weight polymer is a methoxymethylated polyamide resin or urethane acrylate.