JPH04246493A - Antifogging agent - Google Patents

Abstract

PURPOSE:To provide an antifogging agent which prevents the formation of water droplets on the surface of a glass plate or a synthetic resin plate (or sheet or film), e.g. a window or a mirror, even under the most severe condition such as during rainfall. CONSTITUTION:An antifogging agent which contains 0.1-1.0wt.% nonionic fluorocarbon surfactant, 2-10wt.% cationic polyelectrolyte, at least 15wt.% 1-3C aliph. monohydric alcohol, 5-70wt.% water, and, if necessary, at least 5wt.% polyhydric alcohol.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention deals with the phenomenon in which water droplets are formed on window glass, mirrors, etc., and which is subject to particularly severe usage conditions. This invention relates to a drip-proofing agent that prevents the formation of drips.

0002

2. Description of the Related Art It is believed that fogging on window glasses, mirrors, etc. is caused by the formation of microscopic water droplets on their surfaces and the diffuse reflection of light. The reason for this is thought to be that when the temperature of the glass surface falls below the dew point, which is the temperature at which dew begins to form, moisture contained in the air condenses to form extremely small water droplets, that is, dew.

[0003] Therefore, when the temperature is relatively low, the temperature of the window glass of houses, automobiles, etc. becomes below the dew point, and fogging occurs on the glass surface. A similar phenomenon also occurs in mirrors in bathrooms and the like. Furthermore, door mirrors have become mainstream in recent cars, replacing traditional fender mirrors.
When driving in the rain, raindrops adhere to the left and right windows, door mirrors, etc. and cause diffuse reflection of light, which can make visibility extremely poor and dangerous for driving.

[0004] In order to deal with these problems, various techniques have been proposed in the past. For example, in order to keep the glass surface above the dew point, there are methods to attach a heating element to the glass and use heat to prevent fogging, methods to blow warm air onto the glass surface to prevent fogging, and methods to prevent fogging between the glass surface and water. Various anti-fogging agents and drip-proofing agents have been developed that use substances that reduce the interfacial tension of the liquid, and are widely used in automobile window glass, house window glass, bathroom mirrors, eyeglasses, etc. Repellent coating agents based on these are also commonly used.

[0005] In this specification, the term anti-fogging agent is used to treat fogging caused by small water droplets, and the term drip-proofing agent is used to treat fogging caused by large water droplets. However, the technical scope of the present invention also extends to antifogging agents.

[0006]

[Problem to be solved by the invention] In order to keep the surface of the glass above the dew point, there are methods such as attaching a heating element to the glass or blowing hot air onto the glass surface, but these solutions are expensive and expensive. New equipment needs to be installed. Furthermore, water-repellent coating agents mainly composed of wax or the like have weak adhesion to glass surfaces, and there is a problem in terms of sustainability of the water-repellent effect. Furthermore, antifogging agents and drip-proofing agents that contain substances that reduce the interfacial tension of the glass surface also have problems in terms of their lasting effects.

For example, as a conventional technique, Japanese Patent Application Laid-Open No. 1986-
Antifogging agents made of various surfactants, polyhydric alcohols, aliphatic alcohols, water, etc. in JP-A No. 4773 and JP-A-63-184086, and JP-A-55-1989
There are antifogging agents that contain polymeric substances (sodium salt, polyvinyl alcohol) as disclosed in Japanese Patent No. 157675, but considering the conditions of use and the properties of the glass surface, even with these antifogging agents, it is difficult to clean the glass surface during rain. The sustainability of the effect of preventing water droplet formation cannot be said to be sufficient. This is because these antifogging agents have a weak retention force on the glass surface of various surfactants that reduce the interfacial tension of water, making it easier for the various surfactants to flow out, resulting in damage caused by rain. This is because the effect of preventing water droplet formation will not last.

[0008] A particular problem to be solved here is that when driving in the rain, raindrops form on the left and right window glasses, door mirrors, etc. and cause diffuse reflection of light, making visibility extremely poor and dangerous for driving. Since raindrops constantly fall on window glass and door mirrors, various surfactants adhering to the glass surface tend to wash away and the drip-proof effect does not last long. In addition, window glass in houses, mirrors in bathrooms, glasses, etc. often come into contact with the human body, so in addition to being drip-proof, they also need to be made with sufficient safety in mind.

[0009]

[Means for Solving the Problems] As a result of intensive studies to solve the various problems mentioned above, the present inventors have developed an anti-fogging agent and a drip-proofing agent that are long-lasting and safe for the human body. However, the present invention has been completed. In particular, by applying the anti-fogging agent and drip-proofing agent of the present invention to window glasses, mirrors, etc. that require anti-fog and drip-proof properties, it is possible to obtain good sustainability. Become.

[0010] The drip-proofing agent of the present invention each contains specific amounts of a nonionic fluorine surfactant, a cationic polymer electrolyte, a monohydric aliphatic alcohol, and water as main components, and further contains a polyhydric alcohol if necessary. It consists of.

The nonionic fluorine-based surfactant used in the present invention is a surfactant whose hydrophobic group has a completely fluorinated perfluorocarbon group instead of a hydrocarbon group. Water to which this nonionic fluorine-based surfactant has been added has a surface tension that is reduced to 10-15 dyn/cm, dramatically improving wetting power and penetrating power, making it easy to clean on low-energy surface substrates. It has the characteristic of spreading wetly. In addition, by coexisting with the cationic polymer electrolyte described below,
Shows remarkable anti-fog and drip-proof properties.

[0012] The type of fluorine-based surfactant must be nonionic or cationic to prevent chemical reactions with the cationic polymer electrolyte, but from the viewpoint of ease of handling, etc. A nonionic surfactant is more preferred, and the hydrophobic group is a perfluoroalkyl group having about 6 to 10 carbon atoms, and may be either linear or branched.

A cationic polymer electrolyte is a water-soluble polymer having a dissociative group in its polymer chain, and when dissolved in water, it dissociates into a cationic polymer ion. Since this polymer ion has a large number of dissociable groups, the molecule as a whole has an extremely large charge, and because of its strong electrostatic potential, it has a very high adsorption property on glass surfaces, which are generally negatively charged.

The cationic polymer electrolyte used in the present invention preferably has a molecular weight of 5,000 to 50,000. When the molecular weight is less than 5000, the charge is weakened,
The adsorption to the glass surface becomes weaker, and the molecular weight becomes less than 500.
If it exceeds 0.00, the viscosity becomes high and handling becomes troublesome.

[0015] This cationic polymer electrolyte exhibits remarkable anti-fog and drip-proof properties when coexisting with the fluorine-containing surfactant, particularly a nonionic fluorine-containing surfactant.

[0016] Examples of the monohydric aliphatic alcohol include one or a mixture of two or more of methyl alcohol, ethyl alcohol, isopropyl alcohol, and normal propyl alcohol.

[0017] Alcohol is useful for diluting and dispersing the various additives mentioned above, as well as for promoting spreading on the glass surface when applied to the glass surface. However, in consideration of safety to the human body, ethyl alcohol It is preferable to use

The water used may be tap water, but it is preferable to use ion-exchanged water or distilled water that does not contain scale. In this case, water serves to prevent the monohydric aliphatic alcohol and the cationic polyelectrolyte from directly mixing and forming insoluble matter.

[0019] Polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol,
Examples include one or a mixture of two or more dipropylene glycols. Since these have a freezing point lowering effect, they are useful for preventing clouding, freezing, etc. of antifogging agents and drip-proofing agents, especially when used in cold regions. In this case, too, it is preferable to use diethylene glycol in consideration of safety to the human body.

[0020]

[Operation and Effects of the Invention] The drip-proofing agent of the present invention mainly contains a nonionic fluorine-based surfactant, a cationic polymer electrolyte, a monohydric aliphatic alcohol, and water, and, if necessary, a polyhydric alcohol. It has great wetting and penetrating power, and has the characteristics of easily wetting and spreading on low-energy surfaces.

In this case, the blending ratio of the nonionic fluorine surfactant is preferably 0.1 to 1.0% by weight, and 0.1% by weight.
If it is less than that, the above effect will be reduced. Also, 1.0% by weight
If the temperature exceeds 100 mL, bubbles are likely to form and become a factor in obstructing visibility.

[0022] The blending ratio of the cationic polymer electrolyte is 2 to 2.
10% by weight is preferable, and if it is less than 2% by weight, the above effects will be reduced. On the other hand, if it exceeds 10% by weight, the viscosity becomes high and handling becomes troublesome, and a waving phenomenon occurs on the glass surface, resulting in distortion of vision due to abnormal refraction of light.

[0023] The monohydric aliphatic alcohol is preferably used in an amount of 15% by weight or more in order to dilute and disperse the various additives mentioned above and to promote spreading on the glass surface when applied. .

[0024] By mixing water with the cationic polymer electrolyte in advance, it is possible to prevent the formation of insoluble substances due to mixing with the monohydric aliphatic alcohol, but if the amount is too large, the sustainability of the effect will decrease. In the mixture of the present invention, the amount of water added is preferably 5 to 70% by weight.

[0025] Since polyhydric alcohol has a freezing point lowering effect, it is useful for preventing clouding, freezing, etc. of antifogging agents and drip-proofing agents, especially when used in cold regions.
The content is preferably 5% by weight or more.

In the present invention, a third component may be included as long as the object of the present invention is not impaired. The drip-proofing agent of the present invention may be used by any conventionally known method such as spraying.

[0027]

[Example] Effect evaluation tests 1) to 3) were conducted using the antifogging agent and anti-drip agent prototyped in the formulation example according to the present invention, as well as known commercially available anti-fogging agents and anti-drip agents. In the method,
The test was carried out at least three times for each sample, and the rate of wetting and spreading on the glass surface was evaluated using the average of the tests.

In the following, the drip-proofing agent or antifogging agent was sprayed using a mist sprayer.

1) After cleaning the surface of the glass watch glass using a cleaner and an oil film remover, spray 1 g of an anti-fogging agent or drip-proofing agent. Water is continuously sprayed on the sprayed area five times (6 g) using a sprayer. A total of 12 cycles are performed, with 5 consecutive water sprays as one cycle.

2) Spray 1 g of an anti-fogging agent or drip-proofing agent onto a window glass of a building. Spray on the sprayed area with a sprayer, 5
Water is sprayed twice (6 g) in succession. A total of 100 cycles are carried out, with 5 consecutive water sprays as one cycle.

3) Using a window glass of a building, an aqueous solution containing 2% by weight of wax is applied to the glass surface. Spray 1 g of anti-fogging agent or drip-proofing agent on the area. Spray water 5 times (6 g) continuously on the sprayed area using a sprayer. A total of 12 cycles are performed, with 5 consecutive water sprays as one cycle.

Specifically, examples of the present invention are shown in Table 1, and comparative examples are shown in Table 2, but the present invention is not limited to these Examples.

Examples 1 to 4 The nonionic fluorine surfactant was fixed at 0.5% by weight, the cationic polymer electrolyte at 5.0% by weight, and the distilled water at 47.3% by weight, with the remaining 47% by weight. These are examples in which 2% by weight of various monohydric aliphatic alcohols were used, and all showed good results.

Examples 5 to 8 Ethyl alcohol was used as the monohydric aliphatic alcohol.
6% by weight, distilled water 44.7% by weight, nonionic fluorine surfactant 0.5% by weight, cationic polymer electrolyte 5.0% by weight, remaining 5.2% by weight. In this example, various polyhydric alcohols were used, and all showed good results.

Examples 9 to 10 In Example 6, ethylene glycol was 10.0% by weight and 15.0% by weight, nonionic fluorine surfactant was 0.5% by weight, and cationic polymer electrolyte was In this example, 5.0% by weight and the remainder equally divided between ethyl alcohol and distilled water showed good results.

Comparative Examples 1 to 2 Comparative Example 1 is a case where distilled water is 4.5% by weight of the blending ratio of Example 2, and Comparative Example 2 is also 75% by weight.
When the content of distilled water is 0% by weight, cloudiness and precipitation occur when the content is 4.5% by weight, and when the content is 75.0% by weight, the durability of the effect decreases.

Comparative Examples 3 to 4 Comparative Example 3 is a case where the nonionic fluorine-based surfactant is 0.05% by weight of the blending ratio of Example 2, and
Comparative Example 4 is a case in which the amount of nonionic fluorine-based surfactant is 1.2% by weight, but when the nonionic fluorine-based surfactant is 0.05% by weight, the duration of the effect decreases, and when it is 1.2% by weight, it is difficult to spray. This tends to cause fine bubbles to form on the glass surface, which is not desirable in terms of ensuring visibility.

Comparative Examples 5 to 6 Comparative Example 5 is a case in which the cationic polymer electrolyte is 1.0% by weight of the blending ratio of Example 2, and Comparative Example 6 is also 11.0% by weight. However, if the cationic polymer electrolyte content is 1.0% by weight, the durability of the effect will decrease, and if it is 11.0% by weight, the viscosity of the entire solution will increase, which is not preferable for spraying.

Comparative Examples 7 to 8 Comparative Example 7 is a case where distilled water is 4.5% by weight of the blending ratio of Example 6, and Comparative Example 8 is the same as 75% by weight.
When the content of distilled water is 0% by weight, a slight clouding occurs when the content is 4.5% by weight, and when the content is 75.0% by weight, the durability of the effect decreases.

Comparative Examples 9 to 10 Comparative Example 9 is a case where the nonionic fluorine surfactant is 0.05% by weight of the blending ratio of Example 6, and
Comparative Example 10 is the same case where the amount is 1.2% by weight,
When the amount of nonionic surfactant is 0.05% by weight, the durability of the effect decreases, and when it is 1.2% by weight, fine bubbles are likely to be generated on the glass surface by spraying, which is not preferable in terms of ensuring visibility.

Comparative Examples 11 to 12 Comparative Example 11 is a case where the cationic polymer electrolyte is 1.0% by weight of the blending ratio of Example 6, and Comparative Example 12 is the case where the cationic polymer electrolyte is 1.0% by weight. However, if the cationic polymer electrolyte content is 1.0% by weight, the durability of the effect will decrease, and if it is 11.0% by weight, the viscosity of the entire solution will increase, which is not preferable for spraying.

[0042]

[Table 1]

[0043]

[Table 2] From the above, the anti-fog agent and drip-proof agent formulated according to the present invention are more effective than known anti-fog agents and drip-proof agents when applied to window glass and door mirrors where raindrops constantly fall. It was found to have excellent long-lasting effects.

Claims (5)

[Claims] Claim 1: The following components (a) 0.1 to 1.0% by weight of a nonionic fluorine surfactant (b) 2 to 10% by weight of a cationic polymer electrolyte (c)
A drip-proofing agent characterized by containing 15% by weight or more of a monohydric aliphatic alcohol having 1 to 3 carbon atoms (d) and 5 to 70% by weight of water. Claim 2: The following components (a) 0.1 to 1.0% by weight of a nonionic fluorine surfactant (b) 2 to 10% by weight of a cationic polymer electrolyte (c)
A drip-proofing agent characterized by containing 15% by weight or more of a monohydric aliphatic alcohol having 1 to 3 carbon atoms (d), 5 to 70% by weight of water (e) and 5% by weight or more of a polyhydric alcohol. Claim 3: The molecular weight of the cationic polymer electrolyte is 500.
0 to 50,000 water-soluble polymer electrolyte, Claim 1
Or the drip-proof agent described in 2. 4. A monohydric aliphatic alcohol having 1 to 3 carbon atoms,
The drip-proof agent according to claim 1, 2 or 3, which is one or a mixture of two or more of methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-propyl alcohol. Claim 5: The polyhydric alcohol is ethylene glycol,
The drip-proof agent according to claim 2, which is one or a mixture of two or more of diethylene glycol, propylene glycol, and dipropylene glycol.