JPH0919669A - Removing method of depositions - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repeatedly clean an object for a short time with the low deterioration of removal performance by fixing a depositions removing coating film composed of a film consisting essentially of a hydrophilic resin swelled but free from flowing out and being eliminated by water and solid in air at ordinary temp. on the surface of the object and removing the depositions on the coating film with water containing a surfactant. SOLUTION: A method for fixing the depositions removing coating film composed of the film consisting essentially of the hydrophilic resin swelled but free from flowing out and being eliminated by water and solid in air at ordinary temp. on the surface of the object and removing the depositions on the coating film with the water containing the surfactant is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing deposits which makes it possible to repeatedly and easily clean an object with a solution containing water as a main component.

[0002]

2. Description of the Related Art Conventionally, it is not easy to remove deposits that are insoluble in water, and even if it is a liquid oil, it is necessary to add a surfactant to the water and wash it with great care. It must be dissolved using an organic solvent that is environmentally problematic.

In particular, if the deposit becomes waxy or solid, it is often difficult to use the surfactant alone.
It requires heavy labor such as using an organic solvent or mechanically scraping it off, and it is often impossible to completely remove it, damage the adherend, or even impossible to remove it.

There is also a method of forming a peelable or dissolvable coating on the surface and removing the deposit with it, but each time a new coating must be formed or extra waste is generated. It is not an essential solution.

On the other hand, there is a Teflon coating as a coating capable of repeatedly removing deposits, but its range of use is narrow due to problems such as high cost, limited surface that can be coated, and low transparency.

As a technique for solving such problems and easily removing deposits repeatedly, a hydrophilic resin which is swelled by water but does not disappear by flowing out and which is solid at room temperature in air is mainly used. There is a coating for easily removing adhered substances (Japanese Patent Laid-Open No. 6-222604) immobilized on the surface of an object, which is characterized by comprising a film as a component.

[0007]

However, when an ionic resin is used as the hydrophilic resin of the coating for easily removing deposits,
In general, it absorbs water quickly and takes a short time to remove deposits,
As the counter ions flow out into water or are replaced with polyvalent ions, the water absorption decreases with time and the removability of deposits also decreases. On the other hand, when a nonionic resin is used, there is a problem in that the deposit removal property is generally not deteriorated, but the time required to remove the deposit is long.

[0008]

SUMMARY OF THE INVENTION The present invention has been made as a result of various studies in view of the above circumstances, and is hydrophilic and swells in water but does not disappear by flowing out and is solid at room temperature in air. Easy removal of deposits consisting of a resin-based film is fixed on the surface of an object, and the deposits on the coating are removed with water containing a surfactant to remove deposits in a short time. It is intended to make it possible to easily clean an object repeatedly with a small decrease in the temperature.

The method of removing deposits of the present invention can remove most of insoluble or sparingly soluble deposits such as oily substances in water, and is more effective when such deposits are used.

The easy removal of deposits when an ionic resin is used reduces the removability of deposits on the coating, and the removal of deposits when a nonionic resin is used for a long period of time reduces the amount of the surfactant. It is considered that the combined use suppresses the effect of removing the essential oily substance of the surfactant and the effect of improving the water permeability, but the exact mechanism is not clear.

The coating immobilized on the surface of the object of the invention is
Although it is necessary to swell with water, it is preferable that the swelling rate is 1.5 times or more in order to effectively remove deposits. The volume swelling rate referred to in the present invention means that a sample having a thickness of several tens of μm and a size of about 1 cm × 1 cm is 5 times in water.
It can be determined by raising the cube of the ratio of the measured length of the sample size before and after the immersion for a minute.

The coating immobilized on the surface of the object of the invention is
For repeated use, it is necessary that it does not flow out and disappear with water, and the gel fraction, which is the proportion of the resin that does not dissolve and flow out, is preferably 50% or more, more preferably 70% or more. As a result, the coating itself can be given some scratch resistance, water resistance and the like.

For this purpose, it is effective to crosslink the hydrophilic resin. The functional group used for crosslinking is an epoxy group,
Examples thereof include an isocyanate group and a double bond, which can be used both as a crosslinking agent and as a functional group in the resin molecule. As the cross-linking agent, an epoxy cross-linking agent, an isocyanate cross-linking agent, a radiation cross-linking agent or the like is preferably used.

Further, in order to suppress the peeling outflow, it is necessary to have adhesiveness and peeling resistance so as not to peel off from the surface of the coated object when immersed in water. It is also effective to provide a layer different from the object on the surface of the object to be treated or coated.

For example, in order to improve the adhesiveness, treatment with parachlorophenol, trifluoroacetic acid, a silane coupling agent, a titanium coupling agent, an azide compound, various polymers or the like or a surface layer can be used. When the swelling rate of the coating is different from that of the object to be coated, a surface layer having a medium swelling rate can be used to absorb the strain generated between them.

The coating immobilized on the surface of the object according to the invention is
A hydrophilic resin that swells with water is required to be a main component, and examples of such a resin include a resin having a polar functional group or a hydrophilic chain, and a resin having a polar functional group or a hydrophilic chain. Specific examples thereof include a carboxylic acid group, a hydroxyl group, a sulfonic acid group, an amide group, an amino group, a phosphoric acid group or salts thereof, and a polyethylene glycol chain.

Resins having these functional groups or hydrophilic chains include acrylic acid, methacrylic acid and vinyl alcohol.
, Hydroxyethyl methacrylate, dihydroxypropyl methacrylate, acrylamido-2-methylpropanesulfonic acid, acrylamide, methacrylamide, N, N-dimethylacrylamide, N-acrylylglycinamide, N-isopropylacrylamide,
N, N-dimethylaminopropyl acrylamide, vinylpyrrolidone, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate,
Allylamine or salts thereof, quaternary amino groups,
Homopolymers, copolymers such as polyethylene glycol,
Examples thereof include copolymers with substances other than the above.

The hydrophilicity of the resin can be evaluated by the receding contact angle with water, and the receding contact angle with water is 40 ° or less, more preferably 20 ° or less, and further preferably 10 ° or less and almost 0 °. A resin that is hydrophilic is preferably used.

The receding contact angle with respect to water is such that a water drop is formed on a resin film, the water is sucked up by a syringe or the like, and the angle at which the water comes into contact with the resin when the end of the water drop starts moving inward with a protractor or the like. You can ask. In addition, when the treatment with a specific aqueous solution is premised and the hydrophilicity is changed by the treatment, it is necessary to measure after dipping and drying in the aqueous solution.

It is also effective to use a substance other than the hydrophilic resin in combination in order to improve various characteristics. For example, inorganic powders, plasticizers, antistatic agents, lubricants, dyes, pigments, dispersants, hydrophobic resins and the like can be used as necessary.

As the surfactant used in the present invention, any of nonionic, anionic, cationic, amphoteric and polymeric surfactants can be used. The effect of removing deposits depends on the object to be removed and the type of coating immobilized on the surface of the object, but typical examples of surfactants include hydrocarbon chains, silicone chains, fluoride chains, and Oxyalkylene chain, ester group, hydroxyl group, mercapto group, carboxylic acid (or salt thereof), sulfonic acid (or salt thereof),
Examples thereof include compounds that combine sulfuric acid (or a salt thereof), amine (or a salt thereof), and the like.

In the present invention, water containing a surfactant is used to remove the deposits. However, other substances such as electrolytes and alcohols may be used in combination, and it is effective depending on the deposits.

As the electrolyte, depending on the type of resin, salt,
A base or acid can be suitably used. Examples thereof include electrolytes such as sodium bicarbonate, sodium chloride, acetic acid, potassium hydroxide, sodium hydroxide, hydrochloric acid, sulfuric acid and nitric acid, and alcohols such as ethyl alcohol, isopropyl alcohol and methyl alcohol. .

Further, by using water containing a resin which is soluble in water, it is possible to replenish the eluting components in the resin of the coating, which is effective in maintaining various characteristics of the coating.

When the water used in the step of removing the deposits is discarded as it is, or when the water may come into direct contact with the human body, the substances contained in the water and the substances eluted from the coating are A substance having a small adverse effect on the environment is preferable, and a biodegradable substance is more preferable.

The deposit removing material of the present invention and the coating using the same need to be solid at room temperature in air to maintain the shape or coating. In consideration of practicality, it is preferable in many cases that the scratch strength during drying is 6B or more in the pencil scratching test with a load of 100 g, and more preferably 2B or more. Further, it is practically preferable that no sticking or adhesion occurs when the coatings are brought into contact with each other.

In the present invention, it is often preferable that the coating has transparency in some applications. In that case, it is generally more preferable that the transparency is 80% or more for all rays or rays having a wavelength of 550 nm.

A sheet having a sheet-like base material to be coated has a wide range of applications. For example, the removable deposit is an ink. This is a typical example in which the present invention exerts excellent effects, and in particular, in the case where the ink adhesion method is copying, printing, or printing, it is possible to solve the problem of paper dust that occurs in an office or the like. It is very effective.

Above all, copying by a copying machine, printing by a printer or typewriter, or an increase in paper dust due to printing is remarkable. Therefore, the coating on the sheet-like base material is compatible with the ink used for these. Have a copy,
It is printable or printable, and is very effective for use in removing these inks.

In particular, it is particularly effective to deal with toner ink used in electrophotographic copying type printers and laser type printers in view of the amount used in recent offices.

Further, it is of course effective to deal with printing by other methods or inks used for printing, and examples of these inks include ink jet inks, heat sensitive ribbon inks, impact inks, typewriter ribbon inks and the like. To be

In this case, it is preferable that the coating on the sheet-shaped base material has heat resistance and mechanical characteristics that are not deteriorated before and after the step of adhering the ink by copying, printing or printing.

As the sheet-like base material, a resin film, paper, metal foil or a composite material or laminate material thereof can be preferably used according to the application, and copying, printing or printing is possible. It is preferable to have sufficient flexibility and thickness, and it is preferable to maintain flatness before and after the ink attaching and removing steps. In other words, it is preferable to have heat resistance, water resistance, mechanical properties, or shape memory that can maintain flatness.

It is also preferable that the coating has a contraction rate or an expansion rate capable of maintaining flatness before and after the step of depositing ink by copying, printing or printing and the step of removing the deposited ink. However, when the coating is provided on both sides of the sheet, a coating having a relatively wide range of shrinkage or expansion can be used. As for the flatness to be maintained, it is preferable that the lifted width of the most lifted portion when the sheet is placed on a flat surface is within 10 mm.

The thickness of the coating in the present invention is 0.
The thickness is preferably from 05 μm to 5 μm, and is 0.1
More preferably, it is not less than μm and not more than 3 μm. If it is thin, the number of times of repeated use is small, and if it is thick, the coating is liable to be damaged during removal of deposits.

The coating for easily removing deposits fixed on the surface of the object of the present invention is required to swell with water,
In a specific application, such as the adhesion of the above-mentioned ink, it is more practically preferable that the swelling required for removing the adhered material is obtained only in a specific temperature range. That is, it is more preferable that the adhered matter is attached but difficult to remove when used at room temperature, and the adhered matter removability is high only in the removal step using a temperature different from room temperature. When the temperature range is 20 ° C. or higher, it is suitable for use and design of the removal process, and more preferably 28 ° C. or higher.

As the resin exhibiting such an effect,
Examples of the resin having a nitrogen-containing group and / or an organic acid group or a combination of resins include a nitrogen-containing group and an organic acid group.
Examples thereof include an amide group, an amino group and a carboxylic acid group. Examples of the resin having these functional groups or a combination of the resins include acrylamide, methacrylamide, N, N-dimethylacrylamide, N-acrylylglycinamide,
H-polymers such as N-isopropylacrylamide, N, N-dimethylaminopropylacrylamide, vinylpyrrolidone, acrylic acid, and methacrylic acid, copolymers, copolymers with substances other than the above, and combinations thereof may be mentioned.

As typical examples, there are combinations of polyacrylic acid, polyacrylamide, polyacrylic acid and polyacrylylglycine amide, polyacrylic acid and polydimethylacrylamide, etc.
Swelling was observed in the presence of water at a temperature of 9 ° C or higher.

In addition, it is generally preferable that the ink can be attached and removed by a specific writing instrument, including the case where the method of attaching the ink is copying, printing or printing.

According to the present invention, a coating for easily removing adhered substances, which is hydrophilic and swells with water but does not disappear by flowing out, is formed on a surface of an object by immobilizing it on a surface of an object. The method of removing deposits by removing the deposits on the coating with water containing a surfactant can be widely used for the purpose of removing deposits, and can be used as follows, for example. .

For the purpose of removing inks, O
It can be applied to HP sheets, paper or paper equivalents, cel drawing sheets, and the like.

For the purpose of removing dirt such as oil, it can be applied to building materials, furniture, ventilation fans, kerosene appliances, electric appliances, gas appliances, tools, tableware, and various other daily necessities. Especially around the kitchen, workplaces that use machines, etc.
It is effective to apply it to those used in places where oil, paint, and other stains are likely to occur, such as workplaces that handle paint.

Further, for masking purposes, it can be applied to painting or creation of graphics.

The fact that it is possible to sufficiently cope with such an application,
As an example, the removal of mechanical oil, which is a relatively easy deposit, and the removal of a deposit of toner ink, which is particularly strongly adhered to toner ink that is printed in copying by a copying machine of an electrophotographic copying system, will be described.

[0045]

Next, an embodiment of the present invention will be described.

Example 1 9 parts by weight of methacrylic acid 1 part by weight of acrylic acid 13 parts by weight of 2-hydroxyethyl methacrylate 13 parts by weight of acrylamide 1 part by weight of N, N-dimethylaminoethyl methacrylate 1 part by weight of azobisisobutyro Nitrile 0.38 parts by weight Isopropyl alcohol 142 parts by weight This composition was placed in a flask equipped with a condenser and reacted at 70 to 80 ° C. for 10 hours while stirring under a nitrogen stream to obtain 15 parts of hydrophilic resin A. Wt% isopropyl alcohol
Solution was obtained. Next, resin A 15% by weight isopropyl alcohol solution 10 parts by weight Epoxy cross-linking agent 0.075 parts by weight [8 parts by weight of glycidyl ether compound of glycerin and polyethylene glycol (ethylene glycol unit about 4) Mixture of 1 part by weight of glycidyl ether compound and 1 part by weight of sorbitol polyethylene glycol-glycidyl ether compound] The above composition was mixed and stirred at room temperature to obtain a resin solution.

Then, the resin solution thus obtained was adjusted to a thickness of 10
A polyethylene terephthalate film coated with 0 μm of easy adhesion (polyurethane treatment) was applied in a thickness of 60 μm, dried and then subjected to high temperature treatment at 110 ° C. for 5 hours, and a 1 wt% aqueous solution of baking soda. Then, the coating film was immersed for 20 minutes in a vacuum and dried to prepare a coating film for easily removing deposits, which was immobilized on the surface of an object formed by crosslinking a hydrophilic resin.

Using the obtained coating film for removing adhered substances, characters were copied by an electronic copying type copying machine and toner ink was adhered thereto, and a surfactant (Emulgen 106) 5 was added.
% The time required to remove the copied characters with the aqueous solution was examined.
As the characters to be copied, 12-point Gothic Kanji was used.

Comparative Example 1 Copy characters were removed in the same manner as in Example 1 except that tap water was used as the liquid used for removing the copy characters.

Table 1 below shows the results.

[0051]

[Table 1]

[0052]

As is apparent from Table 1 above, the method for removing deposits (Example 1) obtained by the present invention is the same as Comparative Example 1
It can be seen that the toner ink can be removed in a short period of time and the removability is small, and can be repeated as compared with the case where no surfactant is used.

Further, not only the machine oil which is a relatively easy deposit, but also the deposit which is particularly strongly adhered among the deposits of the baked toner can be easily and repeatedly removed. Needless to say, it is the same.

Therefore, according to the method for removing deposits obtained by the present invention, the deposits can be removed in a short time with a small decrease in removability, and the deposits can be repeatedly removed, and the objects can be reused, cleaned, masked, etc. It turns out to be effective.

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Claims (1)

[Claims] 1. An easy-adhesion-removing coating comprising a hydrophilic film which is swelled by water but does not disappear by flowing out and which is solid in air at room temperature and fixed on the surface of an object. A method for removing deposits, wherein the deposits above are removed by water containing a surfactant.