JPS58217578A - Antifogging agent - Google Patents

Abstract

PURPOSE:To provide an antifogging agent having an excellent and durable antifogging effect, prepared by the combined use of a polymethacrylic acid or methacrylic acid/acrylic acid copolymer and a surfactant. CONSTITUTION:The antifogging agent consists of a polymethacrylic acid or a copolymer of methacrylic and acrylic acids and contains water and/or alcohol as solvent. The polymethacrylic acid and the methacrylic acid/acrylic acid copolymer has a degree of polymerization of 500-10,000, pref. 1,000-3,000. When it exceeds 10,000, the antifogging effect is lessened. The surfactant should pref. have excellent detergent action and hygroscopicity and it includes sodium dodecylbenzenesulfonate and polyoxyethylene alkyl ether.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an anti-fogging agent for the surface of transparent materials such as glass, and its purpose is to have an excellent anti-fogging effect, long-lasting effect, and to form a transparent and uniform coating. The object of the present invention is to provide an anti-fogging agent that can be applied to the surface of a material.

It is a common phenomenon in everyday life for glasses to become ridged when you enter a warm room from a cold place, or for glasses to fog up due to the steam from a steaming towel on a cold morning. Clouding caused by the adhesion of minute water droplets not only causes great inconvenience, but can also be dangerous in some cases.

In order to prevent water droplets from sticking to the surface, wetting agents such as soda soap, soap, funnel oil, nitrous sulfate, fatty acid esters, polyethylene glycol, etc., are used to coat the surface of glass, etc. Anti-fogging agents based on surfactants have been considered and are commercially available. These anti-fog agents reduce the surface tension of the water that condenses on the glass surface so that the water does not reach the state of water droplets and forms a uniformly spread thin film that wets the surface. It is effective.

However, since these anti-fogging agents are mainly composed of surfactants, they tend to run off due to condensed water, and have the disadvantage of having poor long-lasting efficacy.

Preferable properties that the anti-fertility agent should have include forming a transparent uniform film on the surface of a transparent substance such as glass, and
The formed film has excellent antifogging performance, and at the same time, it has good adhesion to the surface of the transparent material and is strong enough to not come off for a long time.

Several proposals have already been made towards anti-friction agents having such properties, but none are in a satisfactory state.

In view of the above, as a result of intensive research, the present inventors have found that by using polymethacrylic acid or a copolymer of methacrylic acid and acrylic acid in combination with a surfactant, an antifogging agent with excellent antifogging performance and durability can be obtained. They discovered this and arrived at the present invention.

That is, the anti-fogging composition of the present invention is a composition containing polymethacrylic acid or a combination of methacrylic acid and acrylic acid and a surfactant, and using water and/or alcohol as a solvent.

As the polymethacrylic acid and the copolymer of methacrylic acid and acrylic acid of the present invention, those having a degree of polymerization of 500 to 10,000 can be used, but those having a degree of polymerization of 1,000 to 30,000 are particularly preferred. If the degree of polymerization is less than 500, it will easily wash off with water and will be insufficient in terms of sustainability.
When it becomes larger than 0, the anti-fog performance decreases. Incidentally, the copolymerization ratio of methacrylic acid and acrylic acid may be in the range of 100% to 20% methacrylic acid and 0% to 80% acrylic acid.

As the surfactant used in the present invention, any yr-surfactant having an affinity for water and polymethacrylic acid and a copolymer of methacrylic acid and acrylic acid can be used. Among them, those with excellent detergency and moisture absorption are particularly preferred, such as sodium dodecylbenzene sulfonate, borioki/egulene alkyl ethyl, ;K') oxy/
Examples include ethylene alkylphenyl ether.

The invention! The composition of each component of the anti-surface agent is effective over a wide range, but the range in which it is transparent, uniform, has no clouding effect, and has a good long-lasting effect is polymethacrylic acid or methacrylic acid and acrylic acid. 0.1 to 101% of co-1 coalescence,
The surfactant ranges from 10 to 50 kg, water and/or alcohol as a solvent ranges from 60 to 90 kg.

In addition, a small amount of an imidapurine-based amphoteric surfactant such as Lipomin OOH (manufactured by Lion Oil Co., Ltd.) may be added to the anti-foaming agent of the present invention for the purpose of imparting bactericidal and anticorrosion properties, or for the purpose of improving the flaking properties. L70 (Jl, L720, L7600.Y2O,06(
Both are manufactured by Shin-Etsu Chemical Co., Ltd.) Polyoxyalkyl phenyl ethers of nonionic surfactants such as Bonox NC
Of course, scales can be added with a small amount of I (manufactured by Lion Oil Co., Ltd.).

The antifogging agent of the present invention has been found to be significantly more effective in maintaining antifogging properties than those of the prior art.

Examples of the present invention are shown below.

Example 1 Polymethacrylic acid (degree of polymerization 2000) 4.0 l quantity Sodium thialkylbenzenesulfonate 15.0 square quantity Pure water 81. A tablet preventive made of the above ingredients was applied to glass and plastic lenses, cooled for 30 minutes in a constant temperature room at -4°C, and then taken out to a room at a room temperature of 20°C and 60% humidity to examine the occurrence of clouding. I repeated this process, but after 10 tests, no clouding occurred.

Example 2 Co-m+aggregate M3 composition ratio of methacrylic acid and acrylic acid 40
: 60, oil-containing IJi3000) 6.0 weight-φ related sodium alkylbenzenesulfonate (Limen if
l+ ljx Libon F) 15.0 offshore weight pure water 82.0% by weight Example 1
In a similar test, no clouding occurred even after 10 repetitions.

) (l u'su 6 Polymethacrylic acid (degree of polymerization 11 JOO) 1.0 oil amount Sodium thialkylbenzenesulfonate (Lion Heavy Life 1 Zone F) 14.0 weight Pre-ethyl alcohol 85.0 Lumi% Example In the tests of 1 and 10, no clouding occurred even after repeated tests of 10.

Example 4 Polymethacrylic acid (degree of polymerization 2L] 00) 4. Om Straw Sodium Thialkylbenzenesulfonate (Lion Oil Lypon F) 14.0 wt% Pure water
72.0% by weight ethyl alcohol
10.0% by weight In a test similar to Example 1,
After 10 repeated tests, no clouding occurred.

Comparative Example 1 Polyacrylic acid (degree of polymerization 500) 0.5 storage amount Sodium thialkylbenzenesulfonate (Lion Oil Libon F) 14.5 m': if% pure water
85.0 Military % In a test similar to Example 1, the anti-seizure properties were comparable to Examples 1 to 4, but some clouding began to occur from the fourth repeated test.

Agent Asamura Hao 4 other people

Claims (1)

[Claims] An anti-fogging agent containing polymethacrylic acid or a copolymer of methacrylic acid and acrylic acid and a surfactant, and using water and/or alcohol as a solvent.