JPS59145275A - Antifogging coating composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which is easy to handle and is excellent in an immediate antifogging effect a persistent antifogging effect, by adding a specified surfactant to a polyvinyl butyral resin. CONSTITUTION:The titled compsn. is obtd. by uniformly dissolving 100pts.wt. polyvinyl butyral (A) (e.g. one having a degree of polymn. of 500-2000 and a degree of butyralization of 65-85%), 1-30pts.wt. nonionic surfactant (B) (e.g. sorbitan monolaurate) and 0.1-10pts.wt. fluorine-contg. surfactant (C) [e.g. perfluoroalkylsulfonate salt (8C), perfluoroalkyl/ethylene oxide (10mol) adduct or perfluoroalkyltrimethylammonium salt] in an alcohol solvent. The compsn. is excellent in an initial antifogging effect (an immediate effect) in particular and the persistence of its effect is satisfactory. When the window pane of automobile,building, etc. is coated with the compsn., an excellent antifogging pane can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antifogging coating composition that can provide antifogging properties.

Currently, glass materials are used for automobile windows and architectural windows, but when environmental conditions such as temperature and humidity change, water droplets adhere to the glass surface, causing fogging and blocking visibility. have.

Conventionally, various anti-fogging techniques have been studied to prevent this, but no sufficient preventive measures have been established yet. for example,
Although a technique for coating with hydrophilic resin has been disclosed, it has poor water resistance and tends to cause the surface to swell when exposed to moisture. There are issues such as the need to do so.

Furthermore, as the simplest method, a method of applying a surfactant to the glass surface has been partially put into practical use, but this method has a drawback in terms of sustainability of the antifogging effect.

Furthermore, anti-fogging properties can also be obtained by pasting a film containing a surfactant, but when applied to glass anti-fogging, there are problems with adhesion to the glass surface, and sufficient transparency is required. I can't get sex.

The present inventors have conducted intensive studies to obtain an anti-fog colting agent that is easy to handle and has an immediate and long-lasting anti-fog effect. It was discovered that a composition to which a surfactant was added gave good results, and after further research, the present invention was completed.

That is, the present invention is an antifogging coating composition characterized by comprising polyvinyl butyral a1 fat, a nonionic surfactant, and a fluorine-containing surfactant.

The polyvinyl butyral resin referred to in the present invention is a thermoplastic resin obtained by butyralizing polyvinyl alcohol with butyraldehyde, and has a degree of polymerization (F') of 500 to 2.00.
It is desirable that the degree of butyralization is about 65 to 85 degrees.

The nonionic surfactant referred to in the present invention may be any surfactant as long as it has good compatibility with polyvinyl butyral resin, has excellent antifogging durability, and transparency. Examples of suitable nonionic surfactants include partial esters of polyhydric alcohols such as nrubitan, nrbitol, mannitol, glycerin, and polyglycerin and fatty acids having 12 to 22 carbon atoms, and ethylene oxide or propylene oxide in these partial esters. Partial esters of polyoxyalkylene polyhydric alcohols with 1 to 20 moles of ethylene oxide or propylene oxide added to alcohols such as alkylarnials having 12 to 22 carbon atoms, aromatic flucols, etc. can give. The amount of these non-iononasal surfactants added to the polyvinyl butyral resin is determined by the antifogging effect and the properties of the coating film. tsutp,
The greater the amount added, the better the antifogging durability becomes, but the plasticizing effect is also less thick and the film becomes softer and becomes sticky and sticky. When used for glass antifogging, 1 to 100 parts by weight of polyvinyl butyral resin.
A suitable amount is 30 parts by weight, preferably 3 to 15 parts by weight.

Next, in the present invention, the fluorine-containing surfactant used together with the nonionic surfactant is a surfactant characterized by containing a fluorine atom in its molecular structure. It has properties that improve the effect. Any fluorine-containing surfactant can be used. Examples of these structures are as follows.

(1) Nonionic Rf OHSRf (0H2), 0H1Rf (OOH
2cH2), □H.

f-A-N-(CH2CH20) m H, etc. (where ar is a fluoroaliphatic or aromatic group having 1 to 20 carbon atoms, R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms) , A is a divalent group such as -802-1-, CO-, and m represents a positive integer of 1 to 50).

(11) Anionic] 14000M1 几f-A-N-014□C00M,
Rf S 03M.

It, f-A-N-(CH20,H2O)m-8o2M
, 几fo(CI-1□)Ins03R.

M, ljf-A-N-(CH2)m-POCOI-1
>z and other alkyl groups with 1 to 20 atoms, A is -8
In a divalent group such as 02-1-〇〇-, M is a hydrogen atom or an alkali metal, and nl represents a positive integer of 1 to 50. )Gii) Cationic CRf -A -NH-OH20H2N+(OH3)3
．． 1, X-1 [几t-N+(CH3)3]・X-
etc. (here, Rf is a fluoroaliphatic or aromatic radical having 1 to 20 carbon atoms, A is a divalent group such as -SO□-1-, CO-, etc., and X- is 0-13""' , Br-, etc.)
2-CH20H20H2CO2- and so on (where Rf is a fluoroaliphatic or aromatic group having 1 to 20 carbon atoms, R is a hydrogen atom or a fluoroaliphatic group having 1 to 20 carbon atoms)
m represents a positive integer of 1 to 50. ) Fluorine-containing surfactant polyvinyl butyral resin 10
The amount added to 0 parts by weight is 01 to 10 parts by weight, preferably 0.5 to 5 parts by weight. If it is less than 01 parts by weight,
The initial effect of anti-fogging properties is poor), and if more than 10 parts by weight is added, the anti-fogging properties may worsen.

The antifogging coating composition according to the present invention includes the above three
Of course, other components may be contained in addition to these components, such as a modifier for improving adhesion to glass, a coloring agent, an ultraviolet absorber, a fragrance, and other resins.

The coating composition of the present invention can be applied to a glass surface to make antifogging glass by applying a solution in which the above-mentioned components are uniformly dissolved by an appropriate means. Any solvent can be used to form a homogeneous solution as long as it dissolves the above components, but preferred are aliphatic alcohols having 1 to 4 carbon atoms, such as methanol, ethanol, isopropyl alcohol, m- Examples include methanol.

As the coating method, any of the spraying method, dipping method, barcoding method, roll coating method, etc. can be applied, but the spray method is preferable because it is the simplest and easier to work with. After coating, the solvent is removed by evaporation at room temperature or by heating.

If necessary, it is possible to pre-treat the glass surface with a primer to improve adhesion, but this composition has excellent adhesion to glass, so this is usually not necessary. .

The thickness of the coating film is related to the durability of anti-fogging, and the thicker it is, the better the durability is. Generally, a thickness of 1 to 20 pm is appropriate for coating workability.

The anti-fog coating composition of the present invention has particularly excellent initial anti-fog effect (immediate effect), and at the same time is satisfactory in sustainability. It is possible to obtain anti-fog glass.

The present invention will be further explained below with reference to Examples.

'PHR' means parts by weight based on 100 parts by weight of polyvinyl butyral resin.

Examples 1 to 7 Nonionic surfactants and fluorine-containing surfactants listed in Table 1 were added to and dissolved in isopropyl alcohol to polyvinyl butyral resin (Pm2O3, degree of butyralization 75%) LOO'PHR. An inpropyl alcohol solution containing 10% by weight of polyvinyl butyral resin was prepared. This solution was spray applied to the glass surface and air dried to form a coating film with a thickness of approximately 5 μm. The initial effect and duration of antifogging properties were measured when the same glass was left with the treated side inside as a lid for a sealed container containing water with a water temperature 10°C higher than the room temperature, and the results are shown in Table 1. I got it.

Initial anti-fogging property: Place the sample in a room set at a specified temperature (normal temperature: 20°C, low temperature: 20°C) and visually observe the state of fogging on the glass surface after 5 seconds. I judged it.

◎: Completely cloudy, no water droplets.

○: A few large water droplets are observed.

△: Many small water droplets.

×: Overall white clouding and anti-fogging durability: In the initial anti-fogging test, it was at room temperature.
The film was further allowed to stand still, and the time required until the antifogging effect began to disappear by visual inspection, that is, until the test was judged as '△' was measured.

It can be seen that all the compositions have excellent initial antifogging effect (immediate effect) and durability.

Comparative Example 1 A coating composition solution was obtained in the same manner as in Example 1 except that the fluorosurfactant was not added.

The initial antifogging properties of this product were not good.

Comparative Example 2 A coating composition solution was obtained in the same manner as in Example 1 except that the nonionic surfactant was not added. The initial antifogging properties of this product were not good.

Comparative Example 3 A solution of the nonionic surfactant Ballu 2205 in isopropyl alcohol was applied in the same amount as the nonionic surfactant in Example 1, and the same initial antifogging properties and antifogging properties as in Example 1 were obtained. Sustainability was investigated. Although the initial antifogging properties were excellent, the antifogging durability was poor.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] (1) An antifogging coating composition comprising a polyvinyl butyral resin, a nonionic surfactant, and a fluorine-containing surfactant. The antifogging coating composition according to claim 1, which is obtained by uniformly dissolving 01 to 10 parts by weight of a thread surfactant in an alcoholic solvent.