JPH0222344A - Production of anti-fogging plastic - Google Patents

Abstract

PURPOSE:To produce an anti-fogging plastic excellent both in anti-fogging properties and in scuff resistance by treating the surface of a plastic substrate having a metal oxide layer formed on the surface thereof with a treating solution containing a specific hydrophilic aromatic hydrocarbon. CONSTITUTION:A metal oxide layer (preferably silicon oxide layer) is formed on (A) the surface of a plastic substrate and (B) the above-mentioned coated plastic substrate is then dipped in a treating solution containing (B1) an aromatic hydrocarbon having one OH group and a functional group other than the OH group (e.g., aminophenol) and/or (B2) an aromatic hydrocarbon having >=2 OH groups (e.g., hydroquinone or resorcin), e.g., a treating solution at pH7-12 containing >=10wt.%, preferably >=30wt.% components (B1) and/or (B2) and an organic solvent (e.g., ethanol), subsequently pulled up and dried to produce the objective anti-fogging plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing an anti-fog plastic having scratch resistance.

(Prior Art) Generally, when the surface temperature of plastic or glass falls below the dew point, minute water droplets adhere to the surface, causing fogging. For example, it is well known that glasses lenses, goggles, car window glasses, etc. fog up when the surrounding temperature suddenly drops.

If such a transparent member becomes foggy, it will not only be uncomfortable because it will not be possible to see what lies ahead (but it may also lead to a serious accident.For this reason, conventional methods have been used to prevent transparent members from fogging). Various anti-fogging techniques have been proposed for this purpose.

For example, JP-A-53-58492 proposes a technique in which the surface of a transparent member is treated with a composition containing a sulfonic acid type amphoteric surfactant and an inorganic salt or acetate. However, this method has the drawback that the hardness of the film formed on the surface of the transparent member is low and the antifogging effect is poor in long-term sustainability. Furthermore, a technique has been proposed in which a surfactant is kneaded into a resin that becomes a transparent member, but this technique has drawbacks such as poor durability of antifogging effect, whitening due to bleeding phenomenon, and surface scratch resistance. Furthermore, there is a method of crosslinking hydrophilic polymers to impart both anti-fogging properties and scratch resistance, and addition of hydrophilic properties by plasma treatment of the surface of a transparent member.

Although methods such as surface grafting have also been proposed.

None of these methods has reached the point where both anti-fog properties and scratch resistance can be practically applied.

(Problems to be Solved by the Invention) The present invention has been made by paying attention to the above-mentioned circumstances, and its purpose is to provide a method for manufacturing an anti-fog plastic having both anti-fog properties and scratch resistance. It is in.

(Means for Solving the Problems) The method for producing an antifogging plastic of the present invention provides two surfaces of a plastic base material on which a metal oxide layer is formed, which has one hydroxyl group and a functional group other than a hydroxyl group. and/or a treatment liquid containing an aromatic hydrocarbon having two or more hydroxyl groups, thereby achieving the above object.

The present invention will be explained in detail below.

A metal oxide layer is formed on the plastic substrate used in the present invention. The means for forming the metal oxide layer is not particularly limited.

For example, physical vapor deposition methods such as vacuum evaporation method and sputtering method, CVO method, plating, etc. can be used. The thickness of the metal oxide layer is preferably as thick as possible in order to improve scratch resistance, but it can be set as appropriate depending on the application. Plastic base materials include polycarbonate,
Allyl diglycol carbonate resin, polymethyl methacrylate.

Polyethylene terephthalate vinyl chloride resin.

Polystyrene, polyimide, polyetherimide polypropylene, high density polyethylene, ABS resin.

Polyether sulfone, polyether ether ketone, etc. are used.

The material constituting the metal oxide layer is 9, for example, SiO□.

SiO, A1.0. , MgO, ZrO,, CaO,
TiO2, Snug.

InzO:+, WOI, MoO3, TazOs
, HfO2, BaO, ZnO, etc. can be used. The metal oxide layer can be a single-layer film formed of these materials, a single-layer film composed of two or more of these materials, or a laminated film formed by laminating these single-layer films. It's okay. In particular, it is preferable that the uppermost layer of the metal oxide layer is formed of silicon oxide or a composition containing silicon oxide.

In this way, the plastic base material whose surface is coated with a metal oxide layer is made of an aromatic hydrocarbon having one hydroxyl group and a functional group other than the hydroxyl group, and/or an aromatic hydrocarbon having two or more hydroxyl groups. It is treated with a treatment liquid containing hydrogen (hereinafter referred to as hydrophilic organic substance J). Here, functional groups other than hydroxyl groups are 5, for example, amino i (-Nl+□),
Carboxyl group (-COOH), sulfo group (-SO, H
), nitro group (NOx), aldehyde group (-CHO)
etc., and therefore.

Examples of aromatic hydrocarbons having one hydroxyl group and a functional group other than the hydroxyl group include aminophenol,
Examples include hydroxybenzoic acid, nitrophenol, hydroxybenzaldehyde, phenolsulfonic acid, and the like. Furthermore, examples of aromatic hydrocarbons having two or more hydroxyl groups include hydroquinone, resorcinol, pyrocatechin, and the like. These may be used alone or in combination. This processing liquid is
A solution containing the above hydrophilic organic substance and an organic solvent, or a solution containing a hydrophilic organic substance, a water-soluble inorganic salt, and a large amount of water can be used.

When the treatment liquid is prepared from a solution containing a hydrophilic organic substance and an organic solvent, the concentration of the hydrophilic organic substance is 10% by weight.
The above is preferable, and in consideration of antifogging performance, 30% by weight or more is more preferable. Further, the pH of the treatment liquid is preferably 7 to 12. The pH of the treatment liquid can be adjusted by adding an aqueous solution containing a base such as sodium hydroxide or ammonia. If the pH of the treatment liquid is too low, the treatment time will need to be extended; if the pH of the treatment liquid is high, the treatment time can be shortened, but the metal oxide layer formed on the surface of the plastic substrate may Elution and peeling are likely to occur. Appropriate treatment temperature and treatment time vary depending on the pH of the treatment solution, the heat resistance of the plastic substrate, and the type of metal oxide layer. For example, when treating a polycarbonate plastic substrate with silicon oxide formed on its surface by vacuum evaporation, a pHIO treatment method consisting of 80% by weight of hydroquinone, 15% by weight of ethanol, and 5% by weight of an aqueous sodium hydroxide solution is used. When used, the treatment temperature is 50~
Preferably, the treatment time is 5 minutes or more at 60°C. An example of an organic solvent that can be used in this treatment solution is ethanol.

Examples include methanol, propatool, butanol, diethyl ether, and the like.

When using hydroxybenzoic acid as the hydrophilic organic substance, this substance is solid and does not dissolve in organic solvents, so dissolve hydroxybenzoic acid powder in a 10 N aqueous sodium hydroxide solution in advance, and It is preferable to add an organic solvent to this solution after adjusting it to a predetermined value. For example, for 60 g of hydroxybenzoic acid, 1
A treatment liquid can be prepared by adding 100 g of a 0N aqueous sodium hydroxide solution to dissolve hydroxybenzoic acid, and then adding 90 g of an organic solvent.

When the treatment liquid is prepared from a solution containing hydrophilic organic substances and a large amount of water, the concentration of these hydrophilic organic substances is 0.
．． It is preferably 1% by weight or more, and more preferably 1% by weight or more in order to shorten processing time. Moreover, the pH of this treatment liquid is preferably 7 to 12.

Yes. Moreover, the pH of this treatment liquid is preferably 7 to 12.

The pH of the treatment solution can be adjusted to 3Jl by adding an aqueous solution containing a base such as sodium hydroxide or ammonia. If the pH of the treatment solution is too low, the treatment time needs to be longer; if the PL of the treatment solution is higher, the treatment time can be shortened, but the metal oxide layer is more likely to elute and peel off. As mentioned above, the treatment temperature and treatment time vary depending on the pH of the treatment liquid, the heat resistance of the plastic substrate, and the type of metal oxide layer. When treating plastic substrates, when using a treatment solution prepared by adjusting the pH of a 10% by weight aqueous solution of hydroquinone with sodium hydroxide, the treatment temperature should be 50 to 60°C and the treatment time should be at least 5 minutes. preferable.

The treatment liquid is a hydrophilic organic substance and a water-soluble inorganic salt.

When preparing a solution containing a large amount of water, the concentration of the hydrophilic organic substance is preferably 0.1% by weight or more, and in order to shorten the processing time, the water-soluble inorganic salt containing the hydrophilic organic substance should be 1% by weight or more. For example, KCI, NaC1゜LiC1,
CaC1z, MgCl2, Li2SO4, K2
Mention may be made of chlorides and sulfates of alkali metals and alkaline earth metals such as SO4, NazSO4°CaSO4, MgSO4, especially NaCl.

LiCl is preferred. The amount of the water-soluble inorganic salt added is preferably as close to the saturated state as possible. Furthermore, the pu of the treatment liquid is 7 to 12
is preferred. The ρ11 of the treatment liquid can be adjusted by adding an aqueous solution containing a base such as sodium hydroxide or ammonia. If the pll of the treatment liquid is too low, the treatment time needs to be extended; if the pll of the treatment liquid is high, the treatment time can be shortened, but the metal oxide layer is more likely to elute and peel. The appropriate processing temperature and time are
As mentioned above, it varies depending on the pH of the treatment liquid, the heat resistance of the plastic substrate, and the type of metal oxide layer. For example, when treating a polycarbonate plastic substrate on which silicon oxide has been formed on the surface by vacuum evaporation, a treatment solution prepared by adjusting an aqueous solution consisting of 10% by weight of hydroquinone and 115% by weight of NaC to puto with sodium hydroxide is used. In this case, it is preferable that the treatment temperature is 50 to 60''C and the treatment time is 5 minutes or more.

Although hydroquinone was explained as a hydrophilic organic substance in the treatment conditions for each treatment liquid above, when processing with a treatment liquid containing a hydrophilic organic substance other than 5-hydroquinone, the treatment conditions are the same as when using hydroquinone. be able to.

The above treatment method involves immersing a plastic base material in a treatment liquid, then pulling the plastic base material out of the treatment liquid, and
A method of cleaning its surface with water, after the plastic substrate is immersed in a treatment solution at room temperature.

The plastic substrate is lifted from the treatment solution, and then 5
A method of heat treatment at 0 to 80°C for several tens of minutes to several hours.

A method of spraying the surface of a plastic substrate with a treatment liquid,
Any treatment method can be employed, such as a method of applying vapor of a treatment liquid to the surface of the plastic base material.

The surface of the antifogging plastic thus obtained exhibits excellent antifogging properties. This is the result of analyzing the surface of anti-fog plastic that has been anti-fog treated.

The metal oxide layer on the surface of the plastic base material and the organic layer formed by hydrophilic particles are chemically bonded.

This is probably because a hydrophilic organic layer is uniformly formed over the entire surface of the antifogging plastic.

In addition, since the organic layer is extremely thin with a thickness of 100 Å or less, it will not be damaged by external force, and the organic layer is chemically bonded to the metal oxide layer and will not peel off. Because there is no.

The antifogging plastic of the present invention exhibits excellent surface abrasion resistance similar to the case where only a metal oxide layer is formed on the surface of a plastic substrate. Moreover.

Anti-fog plastics also have significantly superior long-lasting anti-fog properties compared to conventional products. Furthermore, when a plastic substrate is treated with a treatment liquid prepared by adding a water-soluble inorganic salt, the amount of hydrophilic organic matter added to the surface of the metal oxide layer can be increased.

(Example) The present invention will be specifically described below based on Examples.

After mixing 80 parts by weight of hydroquinone, 15 parts by weight of ethanol, and a small amount of water, add 1 standard aqueous sodium hydroxide solution to bring the pH of the solution to 10, then add water to the solution to make 100 parts by weight. A processing solution was obtained.

On the other hand, polycarbonate was used as a plastic base material, and a silicon oxide (Si(h)) film with a thickness of about 2 μm was formed on the polycarbonate surface by vacuum evaporation.Next, a silicon oxide layer was formed in this manner. The coated polycarbonate was immersed in the above treatment solution for 60 minutes.
After being treated at °C for 30 minutes, it was taken out from the treatment solution and dried to obtain an anti-fog plastic.

Next, the anti-fog properties and scratch resistance of this anti-fog plastic were evaluated. The anti-fog property was evaluated by keeping the anti-fog plastic in an atmosphere of 40% relative humidity at 15°C for 10 minutes or more, then leaving it in an atmosphere of 90% relative humidity at 40°C. After wetting the plastic surface, wipe it with a cloth. This operation was repeated and evaluation was made based on the number of times the surface of the antifogging plastic started to become cloudy. The scratch resistance was evaluated by applying mooo steel wool to the anti-fog plastic surface, rotating it 20 times with the steel wool pressed against the anti-fog plastic surface with a set load, and then
Expired air was blown onto the surface of the anti-fog plastic, and the maximum load at which the anti-fog plastic surface did not fog due to the exhaled air was shown.

The results are shown in Table 1.

As shown in Table 1, an antifogging plastic was obtained by processing in the same manner as in Example 1, except that the composition of the processing liquid and the processing conditions were changed. In Example 6, about 100 parts by weight of an aqueous sodium hydroxide solution was added and mixed with 60 parts by weight of hydroxybenzoic acid, and then 90 parts by weight of an organic solvent was added to prepare a treatment liquid. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 1.

1 application 1 On the polycarbonate surface, 5iOz/Mg0=4/1
A metal oxide layer having a composition (weight ratio) of 2 μI was formed by vacuum evaporation. This metal oxide layer-coated polycarbonate was treated in the same manner as in Example 1, except that the composition of the treatment liquid and the treatment conditions were changed as shown in Table 1 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 1.

A silicon oxide layer (SiO□) with a thickness of about 2 μm was formed on the polycarbonate surface by a vacuum one-layer method, and a titanium oxide layer (TiOz) with a thickness of 0.5 μm was further formed thereon. This metal oxide layer coated polycarbonate was prepared in Table 1.
Other than changing the composition of the processing solution and processing conditions as shown in
An antifogging plastic was obtained by processing in the same manner as in Example 1. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 1.

A silicon oxide layer (SiO) with a thickness of 0.1 .mu.m was formed on the surface of the epoxy polycarbonate by vacuum evaporation, and a silicon oxide layer (SiO.sub.2) with a thickness of 4 .mu.m was further formed thereon. This metal oxide layer-coated polycarbonate was treated in the same manner as in Example 1, except that the composition of the treatment liquid and the treatment conditions were changed as shown in Table 1 to obtain an antifogging plastic.

The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 1.

For comparison, a silicon oxide layer (SiOz) with a thickness of 2 μm was formed on the surface of polycarbonate by vacuum evaporation.

The antifogging properties and scratch resistance of this metal oxide layer-coated polycarbonate were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparison I The antifogging properties and scratch resistance of commercially available products coated on the surface of the allyl diglycol carbonate resin were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Leaving space below) After mixing 30 parts by weight of hydroquinone with water, add a normal aqueous sodium hydroxide solution to bring the p)I of the solution to 10, then add water to the solution to make 100 parts by weight. A treatment solution was obtained.

On the other hand, polycarbonate was used as a plastic base material, and a silicon oxide (SiO□) film having a thickness of about 2 μl was formed on the surface of the polycarbonate by vacuum evaporation. The polycarbonate thus coated with a silicon oxide layer was immersed in the treatment solution described above and heated at 60°C.
After processing for 30 minutes.

It was taken out from the treatment solution and dried to obtain an antifogging plastic.

The antifogging properties and scratch resistance of the obtained antifogging plastic were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Disaster Report 1-17 As shown in Table 2, an antifogging plastic was obtained by processing in the same manner as in Example 10, except that the composition of the processing liquid and the processing conditions were changed. In addition, in Example 12, 1
A treatment solution was prepared by adding and dissolving a 0N aqueous sodium hydroxide solution and then adding water. Next, the antifogging properties and scratch resistance of this antifogging plastic were evaluated in the same manner as in Example 1. The results are shown in Table 2.

5iOz/Mg0=4/l on the polycarbonate surface
A metal oxide layer having a composition as follows (weight ratio) was formed to a thickness of 2 μm by vacuum evaporation. This metal oxide layer-coated polycarbonate was treated in the same manner as in Example 10, except that the composition of the treatment liquid and the treatment conditions were changed as shown in Table 1 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Chimney Flame ■ A silicon oxide layer (SiO□) with a thickness of about 2 μm is formed on the polycarbonate surface by vacuum evaporation.

Further on top of that is a 0.5 μm thick titanium oxide layer (TiO
z) was formed. This metal oxide layer-coated polycarbonate was treated in the same manner as in Example 10, except that the composition of the treatment liquid and the treatment conditions were changed as shown in Table 2 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 2.

A silicon oxide layer (SiO) with a thickness of 0.1 μm was formed on the surface of the polycarbonate by vacuum evaporation, and a silicon oxide layer (SiO□) with a thickness of 4 μm was further formed thereon. This polycarbonate coated with a metal oxide layer was treated in the same manner as in Example 10 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Left below) 10 parts by weight of hydroquinone and 115 parts by weight of NaC.

After mixing the water, an aqueous sodium hydroxide solution was added to adjust the pH of the solution to 10, and then water was added to the solution to obtain 100 parts by weight of a treatment liquid.

On the other hand, polycarbonate was used as a plastic base material, and a silicon oxide (SiO□) film having a thickness of about 2 μm was formed on the surface of the polycarbonate by vacuum evaporation. The polycarbonate thus coated with a silicon oxide layer was immersed in the above treatment liquid and treated at 60°C for 30 minutes, then taken out from the treatment liquid and dried to obtain an antifogging plastic.

The antifogging properties and scratch resistance of the obtained antifogging plastic were evaluated in the same manner as in Example 1. The results are shown in Table 3.

As shown in Table 3, antifogging plastics were obtained in the same manner as in Example 2I, except that the composition of the treatment liquid and the treatment conditions were changed. In addition, in Example 23, 1 was added to hydroxybenzoic acid.
After adding and dissolving 0N sodium hydroxide, water was added to prepare a treatment liquid.

Next, the antifogging properties and scratch resistance of this antifogging plastic were evaluated in the same manner as in Example 1. The results are shown in Table 3.

On the surface of the cliff nail polycarbonate, 5iOz/Mg0=4/1
A metal oxide layer having a composition as follows (weight ratio) was formed to a thickness of 2 μm by vacuum evaporation. This metal oxide layer-coated polycarbonate was treated in the same manner as in Example 21, except that the treatment conditions were changed as shown in Table 2 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 3.

A silicon oxide layer (SiOz) with a thickness of approximately 2 μm was formed on the surface of the polycarbonate plate by vacuum evaporation.

Further on top of that is a 0.5 μm thick titanium oxide layer (TiO
z) was formed. The processing conditions for this metal oxide layer-coated polycarbonate were changed as shown in Table 1.

An antifogging plastic was obtained in the same manner as in Example 21.

The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 3.

A silicon oxide layer (Sin) with a thickness of Ool μ- was formed on the surface of the polycarbonate by vacuum evaporation, and a silicon oxide layer (SiOz) with a thickness of 4 μm was further formed thereon. This polycarbonate coated with a metal oxide layer was treated in the same manner as in Example 21 to obtain an antifogging plastic. The anti-fog properties and scratch resistance of this anti-fog plastic were evaluated in the same manner as in Example 1. The results are shown in Table 3.

(Hereinafter, blank spaces) (Effects of the Invention) As described above, according to the present invention, it is possible to obtain an anti-fog plastic that is excellent in both anti-fog properties and scratch resistance. Therefore,
Two examples of this anti-salt plastic.

When applied to eyeglass lenses, goggles, car window glass, etc., fogging does not easily occur even when there are sudden temperature changes in the surrounding area.
It is comfortable to use and can improve safety.

Below

Claims (1)

[Claims] 1. The surface of the plastic base material with a metal oxide layer formed on the surface is treated with an aromatic hydrocarbon having one hydroxyl group and a functional group other than a hydroxyl group, and/or an aromatic hydrocarbon having two or more hydroxyl groups. A method for producing an anti-fog plastic, including a step of treating with a treatment liquid containing hydrogen.