JPH08151567A - Antifogging agent composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition, comprising a specific polymer containing silicon, a specified amount of an inorganic colloidal sol and water or a water-soluble solvent, excellent in water resistance and capable of imparting antifogging properties sustaining for a long period to the surface of a molding such as glass or a synthetic resin. CONSTITUTION: This composition comprises (A) a copolymer obtained by carrying out the solution copolymerization of 99-50% α,β-ethylenically unsaturated monomer such as (meth)acrylic acid or maleic acid (anhydride) with 1-50% unsaturated monomer of the formula containing a hydrolyzable silyl group such as γ-glycidoxypropyltrimethoxysilane, (B) an inorganic colloidal sol (e.g. a granular or a feathery silica sol or alumina sol having 5-100nm average particle diameter in the case of a spherical shape and 40-150nm major axis and 5-40nm minor axis in the case of the feathery shape) and (C) water or a water- soluble solvent (e.g. isopropyl alcohol). The weight ratio of the component (B) to the component (A) is 0.4-7.0.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antifogging composition. In particular, the present invention relates to an antifogging agent composition capable of imparting antifogging property to the surface of various products made of glass or synthetic resin material and also maintaining the antifogging property for a long period of time.

[0002]

2. Description of the Related Art In recent years, various thermoplastic resins have been industrially produced and used in a wide variety of fields. Since many of the molded products produced from these thermoplastic resins have a hydrophobic surface, depending on the conditions such as temperature and humidity in which the molded product is used, the surface of the molded product may become cloudy, causing various inconveniences. I'm coming. For example, in goggles and safety glasses that use lenses made of synthetic resin, the visibility is impaired due to fogging, and in a food packaging film, the contents are difficult to see due to fogging. Further, in the agricultural film used in the greenhouse, the penetration of sunlight due to fogging becomes poor, and the water droplets produced by slowing the growth of plants or collecting fine water droplets of cloudy water fall on the cultivated plant, The young shoots may be harmed or cause disease.

In order to eliminate such inconvenience, it is known to impart antifogging property to the surface of a thermoplastic resin molded article. For that purpose, the thermoplastic resin is made hydrophilic such as a surfactant. A method of kneading a hydrophilic substance into a molded article or a method of coating a surface of the molded article with a hydrophilic substance or a water-soluble polymer substance is adopted.

[0004]

However, in the kneading method, the hydrophilic substance kneaded in the thermoplastic resin is blown out and coordinated on the surface of the molded article to give the molded article antifogging property. It has a drawback that it easily flows out with water and loses its antifogging property in a short period of time.

On the other hand, as a coating method, a method of coating a mixture of an inorganic aqueous sol and a surfactant has been proposed. For example, Japanese Examined Patent Publication No. 50-11348 has a surfactant as a main component and a small amount of silica sol added thereto, and Japanese Examined Patent Publication No. 49-32668 has a surfactant added to an alumina sol. JP-A-58-29831 discloses colloidal silica to which a small amount of a water-soluble aluminum salt is added. However, since these mixtures have poor adhesion to the organic thermoplastic resin, the formed coating film may fall off over time and the antifogging effect cannot be maintained for a long time.

In order to improve the above-mentioned drawbacks, a method of adding a surfactant and a hydrophilic polymer to alumina sol (Japanese Patent Laid-Open No. Sho 5).
1-81877, etc.), a method of adding a hydrophilic polymer and a surfactant to colloidal silica (JP-A-57-11).
9974, etc.), etc., but these compositions contain hydrophilic polymers such as polyvinyl alcohol and hydroxyl group-containing acrylic resin for the purpose of exhibiting miscibility with an inorganic aqueous sol. Coatings tend to be inherently poor in water resistance. Therefore, when constantly exposed to high humidity conditions, the inorganic aqueous sol is washed away with the hydrophilic polymer or causes poor dispersion, and the antifogging effect is impaired in a short period of time, which is not practically satisfactory.

To further improve the above-mentioned drawbacks, for example, JP-A-55-99976 and JP-A-55-99987.
In the publication, a method of imparting anti-fogging property with an inorganic-organic composite reaction product composed of silica / hydrophilic polymer / organosilicon compound is proposed. However, these methods also do not have sufficient water resistance, and therefore do not have sufficient antifogging durability. MEANS TO SOLVE THE PROBLEM The present inventor has studied earnestly to provide an antifogging composition capable of solving the conventional problems as described above and having excellent water resistance and imparting long-term antifogging property to the surface of a molded article. As a result, the present invention has been completed.

[0008]

[Means for Solving the Problems] That is, the gist of the present invention is that the scale comprises the following components (A), (B) and (C), and the solid content of the component (B) relative to the component (A). The antifog composition has a weight ratio of 0.4 to 7.0. (A) Copolymer obtained by solution polymerization of 99 to 50% of α, β-ethylenically unsaturated monomer and 1 to 50% of hydrolyzable silyl group-containing unsaturated monomer (B) Inorganic colloid sol (C) Water and / or water-soluble solvent

The present invention will be described in detail below. Specific examples of the α, β-ethylenically unsaturated monomer which is one component of the component (A) of the present invention include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and croton. Α, β-ethylenically unsaturated carboxylic acids such as acid and itaconic acid; α, β-ethylenically unsaturated sulfonic acids such as ethylenesulfonic acid; 2-acrylamido-2-
Methyl propanoic acid; α, β-ethylenically unsaturated phosphonic acids; Vinyl-containing hydroxyl monomers such as hydroxyethyl of acrylic acid or methacrylic acid; Acrylonitriles; Acrylamides; Having vinyl group and oxirane ring in the same molecule Examples thereof include glycidyl esters of acrylic acid or methacrylic acid such as glycidyl (meth) acrylate and allyl glycidyl ether. These monomers may be used alone or in combination of two or more kinds.

The other component (A), hydrolyzable
Specific examples of the rilyl group-containing unsaturated monomer include
For example, CH₂= CHSi (OC₂H_Five)₃, CH₂= CH
Si (OCH₃)₃, CH₂= C (CH₃) COOC₃
H₆Si (OCH₃)₃, CH ₂= C (CH₃) COO
C₃H₆Si (OC₂H_FourOCH₃)₃, CH₂= CH
COOC₃H₆Si (OC₂H_FourOCH₃)₃, CH₂
= C (CH₃) COOC ₃H₆Si (OCH₃)₂CH
₃Silane coupling agents such as NH;₂C₃H₆Si (O
C₂H_Five)₃, NH₂CONHC₃H₆Si (OC₂H
_Five)₃ , NH₂C₂H_FourNHC₃H₆Si (OC
H₃)₃A silane coupling agent having an amino group such as;
HSC₃H₆Si (OC₂H_Five)₃Mercapto groups such as
A silane coupling agent having;

[0011]

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Examples thereof include silane coupling agents having a glycidyl group. These monomers may be used alone or in combination of two or more kinds.

The component (A) of the present invention is a copolymer obtained by solution polymerization of 99 to 50% of an α, β-ethylenically unsaturated monomer and 1 to 50% of a hydrolyzable silyl group-containing unsaturated monomer. It is a polymer. Specifically, for example, a silane coupling agent, a silane coupling agent having an amino group, or a silane coupling agent having a mercapto group

[0014]

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There are copolymers of glycidyl group-containing silane coupling agent and α, β-ethylenically unsaturated carboxylic acid, and the like. Both of these monomers are used as components of the polymer. A silane coupling agent having a glycidyl group in the copolymer containing an acid may be subjected to an addition reaction later, and further, a monomer having an amino group in the copolymer having a glycidyl group may be added. You may use what added-reacted. Further, if the content of the hydrolyzable silyl group-containing unsaturated monomer is less than 1%, the antifogging property and the antifogging durability will be poor,
On the other hand, if it exceeds 50%, it is not preferable in terms of film formation and cost.

The component (A) of the present invention is synthesized by an ordinary solution polymerization method, and the solvent for the polymerization is
C _{1 to} C ₃ alcohols such as methanol, ethanol and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; hydrophilic solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and glycol ethers such as ethylene glycol monobutyl ether Is preferred. The polymerization form may be random, graft or block polymerization.

The polymerization initiator may be any one used in ordinary polymerization, for example, peroxides such as benzoyl peroxide, t-butylperoxybenzoate, t-butylperoxy-2-ethylhexanoate and the like. Azo polymerization initiators such as azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile and the like can be used .

Examples of the inorganic colloid sol which is the component (B) of the present invention include silica, alumina, water-insoluble lithium silicate, iron hydroxide, tin hydroxide, titanium oxide,
Examples of the aqueous sol include inorganic aqueous colloid particles such as barium sulfate dispersed in water or a hydrophilic medium by various methods. These may be used alone or in combination.
The shape of the inorganic colloid sol used may be spherical or feather-like, and if the shape is spherical, the average particle size is 5 to 5.
In the case of 100 nm, and in the case of feathers, the major axis is preferably 40 to 150 nm and the minor axis is preferably 5 to 40 nm. Within the range, colloidal sols having the same or different particle shapes may be used in combination.

The content of the inorganic colloid sol is 0.4 to 7 relative to the component (A) in terms of solid content weight ratio. If it is less than 0.4, sufficient anti-fog effect cannot be exerted, and
When it exceeds 7, not only the antifogging effect does not improve in proportion to the compounding amount, but also when the molded product is transparent, the coating film formed after coating becomes cloudy to reduce the light transmittance, and
It is not preferable because the coating film is rough and easily becomes weak.

A cross-linking agent is preferably added to the antifogging composition of the present invention. Examples of the cross-linking agent include phenol resins, aziridine compounds, azo compounds, isocyanate compounds, epoxy compounds, silane compounds and the like, and azolidine compounds and epoxy compounds are particularly preferable.

Specific examples of the epoxy compounds include a reaction product of bisphenol A or bisphenol F with epichlorohydrin, a reaction product of a resin reaction product of phenol (or a substituted phenol) with formaldehyde, and epoxidation produced with epichlorohydrin. By epoxidation using a novolac resin, epichlorohydrin and a resinous reaction product formed from an aliphatic polyhydric alcohol such as glycerol, 1,4-butanediol, poly (oxypropylene) glycol or similar polyhydric alcohol components and peracetic acid. The obtained resin or the like is used.

The antifogging agent composition of the present invention contains water and / or a water-soluble solvent as the component (C) and, if necessary, other liquid dispersion medium. Examples of the liquid dispersion medium include water; monohydric alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; polyhydric alcohols such as ethylene glycol and glycerin; cyclic alcohols such as benzyl alcohol; cellosolve acetates; ketones. Can be given. These liquid dispersion media may be used alone or in combination, but the dispersion stability of the antifogging agent composition according to the present invention, the wettability after coating on the surface of a molded article, the difficulty of removing the liquid dispersion medium, and the economy. It is preferable to decide in consideration of sex.

The antifogging agent composition according to the present invention can be applied to the surface of a molded article, and the liquid dispersion medium can be volatilized by forced drying or natural drying. As a method of forced drying, a hot air drying method, an infrared radiation method, or the like can be adopted. The heating temperature for forced drying is determined depending on the applied antifogging agent composition, but is 50 to 250 ° C., preferably 70 to 250 ° C.
It is in the range of 200 ° C.

The molded article to which the antifog composition according to the present invention can be applied is not particularly limited as long as it does not impair the characteristics of the present invention. In general, the molded products whose characteristics are remarkably recognized include plastics, inorganic glass, transparent ceramics, metals, mirror surface materials and the like. Among them, examples of particularly high practical value include plastic molded products, plastic films, inorganic glass lenses, windows of buildings, windows of bathrooms, windows of vehicles such as automobiles or trains, aircraft, ships, etc. .

To apply the antifogging composition according to the present invention to the surface of a molded article, a roll coating method, a dip coating method,
Any known method such as a brush coating method, a spray coating method, a bar coating method or a knife coating method may be used. The amount of the solid matter deposited after the antifogging agent composition is applied to the surface of the molded article and the liquid dispersion medium is dried and volatilized is 0.01 to
1.0 g / m ^2, preferably in the range of 0.1-5 g / m ^2. When the adhesiveness between the surface of the molded article and the coating film derived from the antifogging agent composition according to the present invention is not sufficient, the surface of the molded article is subjected to plasma treatment before applying the antifogging agent composition, Alternatively, it is preferable to modify the surface of the molded product by performing corona discharge treatment or the like.

[0026]

EFFECTS OF THE INVENTION By applying the antifogging composition of the present invention to the surface of a molded article, it exhibits excellent antifogging property for a long period of time and is useful as an antifogging composition for various molded articles. is there.

[0027]

EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Examples 1 to 6 Comparative Examples 1 to 4 (1) Preparation of component (A) 150 parts of isopropyl alcohol was placed in a 1 liter flask equipped with a stirrer and a condenser, and the temperature was set to 80 ° C. under a nitrogen stream. The temperature is raised to 300 parts, and 300 parts of the mixture of the monomers shown in Table 1 is dissolved in 50 parts of isopropyl alcohol and added dropwise over 3 hours. 30 minutes, 60 minutes, 18
After being added dropwise 0 minutes and 3 times, the mixture is reacted at 80 ° C. for 2 hours to give a hydrolyzable silyl group-containing composition (resin solution).
I got To 100 parts of this resin solution, 6 parts of acid was added and diluted with water to obtain a slightly yellowish polymer solution having a nonvolatile content of 30%.

(2) Preparation of Antifog Composition Various kinds of antifog are prepared by blending the products (resins a to c) obtained in the above production examples with the inorganic colloid sols of the types and amounts shown in Table 2. The agent composition was prepared.

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

(3) Formation of coating film and evaluation of coating film The obtained antifogging agent composition was applied on the surface of a molded article by a bar coating method as shown in Table 3 after the coating amount (solid content). Coating) to be 0.5 g / m ² and 85 ℃
It was made to stay in the hot air of 1 minute and the solvent was scattered. Regarding the properties of the coating film formed on the obtained molded article, various properties were evaluated by the methods described below.

Adhesion Adhesion of cellophane tape to the surface of the molded product on which the coating film has been formed,
When the cellophane tape was peeled off, the peeling condition of the coating film was visually observed. The results are shown in Table 3. The evaluation criteria are as follows. ○: The coating film did not peel off and remained completely. ◯ x: 2/3 or more of the coating film remained without peeling. B: 2/3 or more of the coating film peeled off. ×: The coating film was completely peeled off.

Transparency The appearance of the molded product was visually observed. The results are shown in Table 3.
The evaluation criteria are as follows. ○ ・ ・ ・ Compared to a molded product not coated with the anti-fog composition,
Almost as transparent. B: Significant decrease in transparency is observed. X: The transparency is extremely deteriorated and cannot be put to practical use.

Anti-fog property a) Condition 1 The upper surface of a water tank containing water is placed with the coating film-formed surface of the molded product facing the inside of the water tank, and the outside temperature is 12 ° C and the inside temperature of the water tank is 18 ° C. After 120 minutes from the time when the molded article was held and placed on the upper part of the water tank, it was visually observed and judged. The results are shown in Table 3. The evaluation criteria are as follows. ◎: Water adhered in a thin film and no water droplets were observed. ○: Water adheres in a thin film, but slightly large water droplets are observed. △: A state in which fine water droplets are partially adhered. ×: A state in which fine water droplets are observed to adhere to the entire inner surface of the molded product. -... State that cannot be determined.

(B) Condition 2 The molded article was placed on the outside of a test field in Aichi prefecture, a single-roofed house (frontage: 2 m, depth: 20 m, ridge height: 2 m, roof slope: 30 degrees) with the surface provided with a coating on the inside of the house. Then, a coating test was performed for one year from September 1993 to August of the following year. During the spreading test, the antifogging property of each molded product was visually observed over time. The results are shown in Table 3. This evaluation criterion is the same as in the case of the above condition 1.

[0038]

[Table 4]

The following is clear from Tables 1, 2 and 3. (1) With the antifogging agent composition according to the present invention, a coating film having excellent adhesion can be obtained when applied to a molded article. (2) The antifogging composition according to the present invention gives a coating film having excellent transparency when applied to a molded article. (3) The coating film derived from the antifogging composition according to the present invention is
Even if the atmosphere in which it is placed changes, for example, when the temperature and humidity are high, the excellent anti-fog effect does not change, and a stable anti-fog effect is exhibited for a long period of time. (4) A coating film derived from a composition consisting of an inorganic colloid sol is inferior in adhesiveness to the surface of a molded article and cannot maintain a long-term antifogging effect.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location C08L 41/00 LJZ (72) Inventor Katsuhiro Fujiwara 2 Oike, Iwazuka-cho, Nakamura-ku, Aichi Prefecture Mitsubishi Chemical (72) Inventor Atsushi Obayashi 2 Oike, Iwatsuka-cho, Nakamura-ku, Nagoya-shi, Aichi Mitsubishi Kagaku MK-V Co., Ltd. Nagoya Office

Claims (5)

[Claims] 1. The following components (A), (B) and (C):
The antifogging agent composition consisting of the component (A) and the solid content weight ratio of the component (B) to the component (A) is 0.4 to 7.0. (A) Copolymer obtained by solution polymerization of 99 to 50% of α, β-ethylenically unsaturated monomer and 1 to 50% of hydrolyzable silyl group-containing unsaturated monomer (B) Inorganic colloid sol (C) Water and / or water-soluble solvent 2. The antifogging agent composition according to claim 1, wherein the weight ratio of the component (C) to the weight of the solid content of the component (A) is 1 to 100%. 3. The antifogging agent composition according to claim 1, wherein the inorganic colloid sol is silica sol and / or alumina sol. 4. The inorganic colloid sol has a granular or feather-like shape, and when the particle diameter is spherical, the average particle diameter is 5 to 100 nm. When the inorganic colloid sol is feather-like, the major axis is 4
The antifogging agent composition according to any one of claims 1 to 3, which has a range of 0 to 150 nm and a short axis of 5 to 40 nm. 5. A solid content weight ratio of 0.1 to the component (A).
The antifogging agent composition according to any one of claims 1 to 4, which is blended with a crosslinking agent of 01 to 0.5.