JPS642158B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anti-fogging agent composition, specifically a coated anti-fogging agent that, when applied to the surface of a synthetic resin molded article, glass, etc., provides a transparent, non-stick coating that can prevent fogging due to adhesion of water droplets over a long period of time. The present invention relates to a composition. In this specification, the property that the surface of glass, synthetic resin moldings, etc. does not become foggy due to adhesion of water droplets is referred to as antifogging property, and the agent that imparts antifogging property is referred to as an antifogging agent. Generally, anti-fog properties are referred to as non-drop properties, and anti-fog agents are sometimes referred to as non-drop agents, but in this specification, to avoid confusion, these will be collectively referred to as anti-fog properties and anti-fog agents, respectively. That's it. Synthetic resin molded products, such as synthetic resin films,
When the surface temperature of the sheet, plate, glass, mirror, etc. falls below the dew point, water vapor in the air condenses on the surface and forms fine water droplets, reducing transparency and causing a so-called clouding phenomenon. . For example, in the case of glass and synthetic resin films used in agricultural greenhouses, this may reduce light transmittance and hinder the growth of crops, or water droplets may fall on the leaves and buds of the crops and cause them to wither. In the case of mirrors, there are inconveniences such as the need to frequently wipe adhering water droplets. As a means to prevent such fogging, methods are used to make the surfaces of these objects hydrophilic so that the contact angle with water approaches 0°. Methods such as applying a substance or kneading the same substance into the material before molding these objects are adopted. In general, kneaded-in type products exhibit anti-fogging properties as the surfactants etc. that have been kneaded bleed out onto the surface, and exhibit anti-fogging properties at the initial stage of use (i.e., initial anti-fogging properties). ) is good, but has shortcomings such as short-lasting antifogging properties and inability to incorporate thermally unstable surfactants. In addition, surface-applied types are used in fields that require advanced anti-fog performance (drop-free performance).
There are two main categories: those using molecular surfactants and those using hydrophilic polymers. Products using molecular surfactants have good initial antifogging properties, but because they are easily washed away with water, the antifogging properties are short-lived and the coating becomes uneven and opaque. Hydrophilic polymers have recently come to be used more frequently, as they have disadvantages such as making the paint film sticky and producing light spots. However, in order to improve the antifogging properties of hydrophilic polymers, it is necessary to increase the hydrophilic part in the molecule, and increasing the hydrophilic part reduces water resistance and shortens the durability of the antifogging properties. There is a contradiction. As a result of various studies to improve the above-mentioned drawbacks of conventional antifogging agents, the present inventors have discovered an excellent antifogging agent that has excellent water resistance and good initial antifogging properties and long-lasting antifogging properties. It was possible to provide a fogging agent. That is, the present invention has a hydroxyl group-containing vinyl monomer component as a main component, and an acid group-containing vinyl monomer component as a main component.
It contains a partially or completely neutralized copolymer containing 0.1 to 30% by weight, an inorganic sol, and a surfactant, and the content ratio of each component is 100 parts by weight of the copolymer neutralized product. 5 as inorganic solid particles
~1000 parts by weight and a surfactant of 0.1 to 50 parts by weight. The antifogging agent composition of the present invention has excellent film-forming properties, can be easily applied to the surface of substrates such as glass and synthetic resin films, and the dried coating film is transparent and non-sticky, providing initial antifogging properties. It has outstanding performance, including excellent durability and antifogging properties, as well as good adhesion to substrates and scratch resistance. In the present invention, the hydroxyl group-containing vinyl monomer component is the main component, and the acid group-containing vinyl monomer component is 0.1 to
There are various partially or completely neutralized copolymers containing 30% by weight. First, the partially or completely neutralized product of the copolymer is
The hydroxyl group-containing vinyl monomer and the acid group-containing vinyl monomer are copolymerized, if necessary, with other monomers that can be copolymerized with these monomers to form the hydroxyl group-containing vinyl monomer component. This copolymer is easily obtained by partially or completely neutralizing the copolymer with an alkali. For example, using a predetermined monomer in a predetermined ratio,
It is partially or completely dissolved in a hydrophilic or water-miscible solvent, a polymerization initiator is added, and copolymerized with heating and stirring under a nitrogen stream, and then an alkali is added to partially or completely neutralize it. Therefore, it can be easily manufactured. Examples of the hydroxyl group-containing vinyl monomer used in the copolymerization include the compounds described in (i) to (iv) below. (i) General formula (In the formula, R ¹ and R ² each represent a hydrogen atom or a methyl group, and R ¹ and R ² may be the same or different. n represents an integer from 1 to 10.) Compound represented. (ii) General formula [In the formula, R represents a hydrogen atom or a methyl group,
X is a chlorine atom, a bromine atom, an iodine atom, or a formula

[Formula] (wherein, R' represents a lower alkyl group having 1 to 4 carbon atoms, and X' represents a chlorine atom, a bromine atom, or an iodine atom, respectively). ] A compound represented by (iii) General formula (In the formula, n represents an integer of 1 to 4.) A compound represented by: (iv) Allyl alcohol represented by the structural formula CH ₂ =CHCH ₂ OH. A particularly preferable hydroxyl group-containing vinyl monomer is hydroxyethyl (meth)acrylate (hereinafter, hydroxyethyl acrylate or hydroxyethyl methacrylate is collectively referred to as hydroxyethyl methacrylate) belonging to the compound (i) above. The following description also follows this description method.), hydroxypropyl (meth)acrylate. Further, examples of the acid group-containing vinyl monomer used in the above copolymerization include the following compounds (a) to (c). (a) Carboxylic acids such as (meth)acrylic acid, itaconic acid,
Examples include maleic acid and fumaric acid. (b) Sulfonic acids Examples include styrenesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid. (c) Phosphonic acids Examples include phosphonic acids represented by the following general formulas (in each general formula, R represents a hydrogen atom or a methyl group, and n represents an integer of 2 to 4). or Particularly preferable acid group-containing vinyl monomers include (meth) belonging to the above (a) carboxylic acids.
It is acrylic acid. The above-mentioned copolymer in the present invention may be a copolymer containing only a hydroxyl group-containing vinyl monomer component and an acid group-containing vinyl monomer component, but it can be copolymerized with both of these monomers. Those containing relatively small amounts of other monomer components are more preferred. Therefore, in the above copolymerization reaction, it is preferable to use, in addition to these two monomers, a relatively small amount of another monomer that can be copolymerized with these two monomers. Other monomers used in such copolymerization include, for example, styrene, vinylterene, vinyl chloride, vinylidene chloride, vinyl acetate, (meth)acrylic esters [such as methyl (meth)acrylate,
(meth)ethyl acrylate, (meth)propyl acrylate, (meth)acrylate n-butyl, (meth)acrylate
t-butyl acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate,
Allyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, N (meth)acrylate,
N-dimethylaminoethyl, N,N-dimethylaminopropyl (meth)acrylate, etc.], N,N-
dimethylaminoethyl (meth)acrylamide,
Examples include vinylpyridine. These other monomers are mainly used to impart appropriate strength to the room-temperature coating film after drying the copolymer neutralized product and to improve the physical properties of the coating film. The amount of other monomers used is 49% by weight of other monomer components in the copolymer.
The amount below is preferably 10 to 30% by weight. Examples of polymerization initiators used in the copolymerization reaction include organic initiators such as benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, tert-butyl peroxide, and 2,4-dichlorobenzoyl peroxide. Oxides: Examples include azo compounds such as azobisisobutyronitrile, azobisisodimethylvaleronitrile, triazobenzene, phenyl azotriphenylmethane, and 1,1'-azobiscumene. These polymerization initiators can be used alone or in combination of two or more. Examples of hydrophilic or water-miscible solvents in the copolymerization reaction include methanol, ethanol, n
- Alcohols such as propanol, isopropanol, n-butanol, secondary butanol, diacetone alcohol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, butyl carbitol; examples include dioxane, tetrahydrofuran, acetone, cellosolve acetate, etc. The copolymer obtained by such copolymerization has a molecular weight of 1,000 to 100,000, preferably 5,000 to 100,000.
50000, and the content of the hydroxyl group-containing vinyl monomer component is 50% by weight or more, preferably 60 to 99.5% by weight.
and the content of acid group-containing vinyl monomer component is
The content of other monomer components is 0.1 to 30% by weight, preferably 0.5 to 20% by weight, and the content of other monomer components is 49% by weight or less, preferably 10 to 30% by weight. In the present invention, the copolymer after such a copolymerization reaction is finally used after being partially or completely neutralized with an alkali. Examples of alkalis used as neutralizing agents include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, ammonia, ethylamine, propylamine, diethylamine, and trimethylamine. The ratio is 0.1 to 1.0 gram equivalent to the combined acid group. The inorganic sol in the present invention includes inorganic aqueous colloid particles such as silica, alumina, water-insoluble lithium silicate, iron hydroxide, tin hydroxide, titanium oxide, barium sulfate, etc. in various ways in water or an aqueous medium containing water. An example is an aqueous sol dispersed in the liquid. Preferred inorganic sols are silica aqueous sol and/or alumina aqueous sol, and particularly preferred is a mixed sol of alumina sol and silica sol in which the weight ratio of solid particles of alumina/silica is (70-40)/(30-60). The smaller the particle size of the inorganic sol is, the more preferable it is from the viewpoint of stability of the antifogging agent, transparency of the coating film, etc., and it is usually sufficient if the particle size is 100 mμ or less. Since inorganic aqueous sols are commercially available under various trade names, they can be appropriately selected from such commercial products and used in the present invention. for example,
Commercially available silica sol products include Ludtux (trade name of DuPont), Narcoda (trade name of Nalco), Cyton (trade name of Monsanto), Cataloid (trade name of Catalysts Kasei), and Snowtex (trade name of Nissan Chemical Industries). There are also commercially available alumina sol such as Beymal (trade name of Dupont) and Alumina Sol-100 (trade name of Nissan Chemical Industries, Ltd.), so these commercially available products can be used as appropriate. Furthermore, the cohesiveness of the liquid can be controlled by adding acid or alkali or salt to the inorganic sol. For example, by adding sodium silicate to silica sol, it is possible to control agglomeration during drying of the coating solution, smoothen the coating film, and increase gloss. In addition, by adding an appropriate amount of a silane coupling agent, a surface treatment agent, etc., the compatibility between the inorganic sol and the copolymer neutralized product can be improved, and the coating film can be made tougher. As the surfactant in the present invention, any of nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants can be used, but particularly preferred are nonionic silicone surfactants, Examples include ethoxylates and propoxylates of polydialkylsiloxanes. The blending ratio of each component in the antifogging agent composition of the present invention is such that the inorganic sol is in the form of inorganic solid particles of 5 to 1000 parts by weight, preferably 20 to 500 parts by weight, based on 100 parts by weight of the neutralized copolymer. The surfactant is present in an amount of 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight. In the antifogging agent composition of the present invention, the copolymer neutralized product contributes to improvement of film forming properties, coating film, film strength, water resistance of the coating film, and drip-free property of the coating film. Therefore, if the copolymer neutralized product is not included, the film-forming properties will be poor, and the strength, water resistance, and drip-free properties of the coating film will be reduced. Furthermore, if the blending ratio of the inorganic sol is less than the above range, the duration of the antifogging property will be shortened, and if it is too large, although it has antifogging property, the degree (level) of the antifogging will decrease and The transparency of the membrane also decreases. Furthermore, if the blending ratio of surfactant is less than the above range, the initial antifogging property and the antifogging level after long-term use will decrease, and if it is too large, the coating film will become too hydrophilic, sticky and antifogging. Sexual duration becomes shorter. The blending ratio of the surfactant to the inorganic sol in the antifogging agent composition of the present invention is 0.1 to 0.1 to 100 parts by weight of the solid particles of the inorganic sol.
Preferably, the amount is 20 parts by weight. In order to apply the antifogging agent composition of the present invention to a base material such as glass or a synthetic resin molded article, the composition is usually mixed with water or a hydrophilic solvent (for example, in the copolymerization described above), if necessary. similar hydrophilic solvents)
It is diluted to a concentration suitable for coating with a mixed solvent and applied by any method such as roll coating, dip coating, brush coating, or spray coating. In this case, if the base material has poor wettability, such as a synthetic resin film, its surface can be subjected to a treatment such as corona discharge in advance. Furthermore, if a mixed solvent of water and a hydrophilic solvent is used as a diluent for the antifogging agent, its applicability is improved, adhesion to the substrate is improved, and the duration of the antifogging property can be extended. As mentioned above, the antifogging agent of the present invention generally has excellent film-forming properties and can be easily applied to the surface of various base materials, and the dried coating film has excellent transparency, and has excellent initial antifogging properties and antifogging properties. It has excellent properties such as good long-lasting properties, excellent adhesion to substrates and scratch resistance, and is non-adhesive and non-sticky. The following is a detailed description of polymer production examples, examples, and comparative examples. Parts in these examples indicate parts by weight. Polymer production example ~ 100 parts of each monomer (mixture) shown in Table 1 below, 0.5 part of azobisisobutyronitrile as a radical polymerization initiator, and each hydrophilic solvent shown in Table 1
200 parts of the mixture was placed in a flask, and stirred and heated for 5 hours at each predetermined temperature shown in Table 1 in a nitrogen atmosphere to cause a polymerization reaction. The component contents of each of the obtained polymers were as shown in Table-1. Next, each alkali shown in Table 1 was added as a neutralizing agent to the polymerized product to neutralize it.

【table】

[Table] Examples 1 to 12 Comparative Examples 1 to 10 Each commercially available inorganic aqueous sol shown in Table 2 below, Various antifogging agent compositions were prepared by blending surfactants and various diluents in the respective proportions shown in Table 2.

【table】

[Table] Each of the obtained antifogging agents was applied to each substrate shown in Table 3 using a bar coater so that the coating amount after drying was 0.5 g/ ^m2 , and the physical properties of the coating film were tested. . The results were as shown in Table 3.

【table】

[Table] As is clear from the results in Table 3, the antifogging agents of each example are significantly superior to the antifogging agents of comparative examples. Examples 13 to 16 Each commercially available inorganic aqueous sol, surfactant, and various diluents shown in Table 4 below were added to the neutralized product (including a hydrophilic solvent) obtained in the polymer production example. were blended in the proportions shown in Table 4 to prepare various antifogging agent compositions. Each of the obtained antifogging agents was applied onto the polyethylene film surface using a bar coater so that the coating amount after drying was 0.5.
g/m ² , and the physical properties of the coating film were tested. The results were as shown in Table-5.

【table】

【table】

Claims (1)

[Scope of Claims] 1 The main component is a hydroxyl group-containing vinyl monomer component,
It contains a partially or completely neutralized product of a copolymer containing 0.1 to 30% by weight of an acid group-containing vinyl monomer component, an inorganic sol, and a surfactant, and the content ratio of each component is the same as that of the copolymer. An antifogging agent composition comprising 5 to 1000 parts by weight of the inorganic sol as inorganic solid particles and 0.1 to 50 parts by weight of the surfactant, based on 100 parts by weight of the substance. 2. The composition according to claim 1, wherein the hydroxyl group-containing vinyl monomer component is a monomer component selected from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate. 3. The composition according to claim 1 or 2, wherein the surfactant is a nonionic silicone surfactant. 4. Claims 1, 2, or 4, wherein the inorganic sol is a mixed sol of alumina sol and silica sol, in which the solid particles have an alumina/silica weight ratio of (70 to 40)/(30 to 60). The composition according to item 3.