JPH01266184A - Anti-fogging agent - Google Patents

Abstract

PURPOSE:To improve the adhesion and water resistance of the title agent, by incorporating a particular terminal functional polymer thereto. CONSTITUTION:A living polymer of ethylene oxide prepd. by polymerizing ethylene oxide in the presence of an anionic polymerization initiator is reacted with an alkoxysilane having 1.1-5 equivalents, based on the initiator, of a halogen-contg. group (e.g., 3-chloropropylmethyldimethoxysilane) in an inert gas atmosphere to prepare a terminal functional polymer having a number- average MW of 200-100,000 and an alkoxysilyl group through a hydrocarbon or sulfonylhydrocarbon group at one terminal or both terminals of polyethylene glycol. If necessary, 100pts.wt. polymer is mixed with 100pts.wt. or less alkoxysilane (e.g., a silane coupling agent) to prepare an anti-fogging agent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an antifogging agent which is made of a low molecular weight polyethylene glycol-based terminal-functional polymer having an alkoxysilyl group at the terminal, and has excellent adhesion and water resistance.

Conventional Technology and Problems Conventionally, antifogging agents made of polyethylene glycol having alkoxysilyl groups at the molecular ends have been produced by reacting polyethylene glycol having epoxy groups at both ends with aminoalkoxysilane. It has been known that an alkoxysilyl group is introduced into the compound via an amino group (JP-A-54-129098).

However, the above-mentioned terminal alkoxysilylated polyethylene glycol has the problem of being difficult to gel and having poor pot life. That is, there is a problem in that the secondary amino group, which is a bridge between the polyethylene glycol and the alkoxysilyl group, further reacts with other epoxy groups to form a network structure and gel.

Means for Solving the Problems The present invention overcomes the above problems by bridging with hydrocarbon groups or sulfonyl hydrocarbon groups.

That is, in the present invention, the number average molecular weight is 200 to 100.
The present invention provides an antifogging agent characterized by comprising a terminal functional polymer having an alkoxysilyl group at one or both ends of polyethylene glycol No. 000 via a hydrocarbon group or a sulfonyl hydrocarbon group.

A stable end-functional polymer can be obtained by bridging the working polyethylene glycol and the alkoxysilyl group with a hydrocarbon group or a sulfonyl hydrocarbon group. Furthermore, by introducing an alkoxysilyl group at the end of the main body made of polyethylene glycol whose molecular weight has been appropriately adjusted, the alkoxysilyl group exhibits excellent reactivity and exhibits good adhesion to inorganic materials such as glass. Furthermore, the alkoxysilyl group undergoes hydrolysis and contributes to the formation of a cured film. On the other hand, polyethylene glycol prevents water droplets from being repelled based on its water absorption function, thereby exhibiting an antifogging function.

Examples of Constituent Elements of the Invention The terminally functional polymer used in the antifogging agent of the present invention has a hydrocarbon group or a sulfonyl hydrocarbon group at one or both ends of polyethylene glycol having a number average molecular weight of 200 to 100,000. It has an alkoxysilyl group via.

Such a terminally functional polymer can be obtained, for example, by reacting a living polymer of ethylene oxide with an alkoxysilane having a halogen-containing group.

The living polymer used preferably has a narrower molecular weight distribution.

The living polymer can be prepared by a known living polymerization method in which ethylene oxide is polymerized in the presence of an anionic polymerization initiator. Incidentally, the preparation of monofunctional living polymers can be carried out, for example (n.

see, tert)-butyllithium, isopropyllithium, ethyl sodium, n-propyl sodium, n-butylpotassium, ethyllithium, 2-ethylhexyllithium, potassium tert-butoxide, sodium methoxide, lithium methoxide, potassium methoxide, potassium It can be obtained by using octoxide, potassium stearyl alcoholade, potassium cumyl, sodium trimethylsilate, lithium trimethylsilate, and the like. On the other hand, a bifunctional living polymer can be obtained by using, for example, a sodium salt or a potassium salt of sodium naphthalene, lithium naphthalene, or α-methylstyrene tetramer.

The vine polyethylene glycol used in the present invention has a number average molecular weight of 200 to 100,000. If the number average molecular weight is less than 200, the resulting antifogging film will have poor strength, and if it exceeds 100,000, the resulting antifogging agent will have poor reactivity with inorganic materials. The degree of polymerization of the living polyethylene glycol can be controlled by the amount of anionic polymerization initiator used. Polyethylene glycol obtained by the living polymerization method has a narrow molecular weight distribution, and it is possible to obtain a terminally functional polymer with a narrow molecular weight distribution.

As the solvent used in the above polymerization treatment, cyclic ethers such as tetrahydrofuran and dioxane, dimethyl sulfoxide, hexamethylphosphoric triamide, and the like are advantageous in terms of polymerization rate and synthesis efficiency. Aromatic hydrocarbons such as benzene, toluene, and cyclohexane are also used. As with other chemicals used, the solvent used is preferably one that has been sufficiently purified so as not to deactivate the living polymer.

As the alkoxysilane for reacting with the living form of polyethylene glycol, those having a halogen-containing group consisting of an alkyl group or a sulfonyl group are used. Typical examples include 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-bromopropyltrimethoxysilane, 2-chloroethyltriethoxysilane, chloromethyldimethylethoxysilane, chloromethylmethyljethoxysilane. , p
Examples include -(chloromethyl)phenyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropyltriethoxysilane, and 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane. When using the alkoxysilane exemplified here, the hydrocarbon group or sulfonyl hydrocarbon group bridging polyethylene glycol and alkoxysilyl group is a propylene group, an ethylene group, a methylene group, a composite group of methylene and phenylene,
It is a composite group of sulfonyl, phenylene, and ethylene. As is clear from this example, the hydrocarbon group or sulfonyl hydrocarbon group bridging the polyethylene glycol and alkoxysilyl group in the terminally functional polymer used in the present invention does not contain active species that cause gelation. Good to have. The amount of the alkoxysilane having a halogen-containing group to be used is preferably at least an equivalent amount, preferably 1.1 to 5 equivalents, based on the activity of the living polymer or the amount of anionic polymerization initiator added.

In addition, when performing a series of treatments from the preparation of a living polymer to the preparation of a terminally functional polymer, the reaction apparatus to be used may be appropriately determined depending on the purity of the target product, synthesis efficiency, etc. From the viewpoint of the purity of the target product, for example, a high vacuum line using the break-seal method, which can remove impurities to a high degree, is preferable.

On the other hand, if the amount of synthesis is medium-sized or higher and synthesis efficiency is given priority, the purity of the target product will be lower compared to the former, but for example, a method using a syringe method under an inert gas or an autoclave method may be used. A method of synthesizing in a closed system is suitable.

When preparing the antifogging agent of the present invention, an alkoxysilane may be added to increase the crosslinking efficiency of the antifogging film. A typical example of the alkoxysilane to be used is a silane-based coupling agent, and any one of vinyl-based, amino-based, epoxy-based, chloro-based, methacryloxy-based, mercapto-based, alkyl-based, etc. may be used, and two types may be used if necessary. The above may be used in combination. The amount added is 10% of the terminal functional polymer.
It is suitably 100 parts by weight or less, especially 50 parts by weight or less per 0 parts by weight. Adding more than the same amount will lead to excessive crosslinking,
The film becomes brittle. In addition, in order to promote the reaction of the alkoxysilyl group, a conventional reaction accelerating catalyst such as an organic tin compound or an ultraviolet absorber may be added in a normal amount.

The antifogging agent of the present invention can be applied, for example, by diluting it with an appropriate organic solvent and applying it to the object to be treated by a known method such as painting or dipping. can. As a result, the alkoxyl group is hydrolyzed by moisture in the air, causing a condensation reaction to form a cured film. At that time, the hydrolysis of the alkoxyl group may be promoted by exposure to water vapor or the like, or the condensation reaction may be promoted by heat treatment or the like.

The antifogging agent of the present invention can be preferably used for antifogging treatment of glass lenses, mirrors, windows, etc., since the alkoxyl groups in the terminally functional polymer exhibit excellent adhesive strength to inorganic materials. can. Furthermore, since polyethylene glycol exhibits good adhesive strength to organic materials such as plastics, it can also be applied to organic materials.

Effects of the Invention The antifogging agent of the present invention is composed of a terminally functional polymer in which polyethylene glycol and alkoxysilyl groups are bridged via an inert group, so it has excellent stability and pot life. . In addition, the alkoxysilyl group at the end of the molecule has excellent reactivity with inorganic materials, and the cured film has excellent adhesion to the object to be treated and exhibits excellent antifogging function over a long period of time. Furthermore, when the antifogging layer is made of a terminally functional polymer with a narrow molecular weight distribution, the antifogging treatment layer has excellent reaction uniformity and is homogeneous.

Examples Reference Example 1 IM (2, ON) tetrahydrofuran solution consisting of the sodium salt of α-methylstyrene tetramer (10%) was placed in a 1e volume reaction tank under high vacuum using the break-seal method.
0 ml of purified tetrahydrofuran and 300 ml of purified tetrahydrofuran were added, and then 50 g of purified ethylene oxide was added. After polymerizing the solution at about 40°C for 24 hours with stirring,
Purified 3-chloropropyltrimethoxysilane 0.8 mo
1 was added thereto, and the mixture was reacted at 40° C. for 24 hours with stirring to introduce a trimethoxysilyl group.

Next, the reaction solution was taken out from the reaction tank and poured into n-hebutane to precipitate the product, which was then separated. During this treatment process, unreacted 3-chloropropyltrimethoxysilane was extracted and removed from the product.

Analysis of the obtained product by gel permeation chromatography (GPC) revealed that it was a polymer with a polystyrene equivalent number average molecular weight of 1,100 (theoretical value 1.300) and a molecular weight distribution of 1.06. .

In addition, the ratio of terminal trimethoxysilyl group/ethylene oxide unit/α-methylstyrene tetramer obtained by analyzing the polymer by 'H-NMR was 1.9/11/1, which indicates that each polymer It was confirmed that trimethoxysilyl groups were introduced into most of both ends.

Reference Example 2 A 1M tetrahydrofuran solution of potassium t-butoxide (151ml) and 300ml of purified tetrahydrofuran were placed in a 1e volume reaction tank under high vacuum using the break-seal method.
1 and then 50 g of purified ethylene oxide. After polymerizing the solution at about 40°C for 24 hours with stirring, 0.6a+ol of purified 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane was added, and the solution was further reacted at 40°C for 24 hours with stirring. A trimethoxysilyl group was introduced.

Next, as in Reference Example 1, the products were classified by date of purification and analyzed by GPC, and as a result, the number average molecular weight in terms of polystyrene was 6.
380 (theoretical value 3,700), and the molecular weight distribution is 1.
It was a polymer of No. 06.

Furthermore, the ratio of terminal trimethoxysilyl groups/ethylene oxide units/l-butyl groups obtained by analyzing the polymer by H-NMR was 0.95/73/1, and most of the terminals of the polymer It was confirmed that a trimethoxysilyl group was introduced.

Comparative Reference Example 50 parts (parts by weight, same hereinafter) of polyethylene glycol diglycidyl ether having 9 ethylene oxide units,
50 parts of N-β-aminoethyl-γ-aminopropyltrimethoxysilane were mixed and reacted at room temperature using a mixer, and 3 hours after the start of mixing, when the viscosity of the reaction system suddenly increased, the mixing operation was stopped.

The purpose of the above reaction operation was to prepare polyethylene glycol having trimethoxysilyl group units at both ends, but after stopping the mixing operation and leaving it at room temperature for 24 hours, it turned into a gel and was not ready for coating. Ta.

Example 1 A 1% by weight acetone solution of the polyethylene glycol having trimethoxysilyl groups at both ends obtained in Reference Example 1 was prepared, applied to a washed glass plate, and dried to form a treated layer with a thickness of about llff1. The treated glass plate was then left in a steam atmosphere for 10 minutes to hydrolyze the methoxysilyl groups in the treated layer, and then heated and dried at 120° C. for 3 hours to harden the treated layer.

The above-mentioned cured film is firmly adhered to the glass plate,
Even after being immersed in hot water at 70°C for 3 hours, it did not peel off from the glass plate.

Example 2 9921 parts of methyltriethoxy was added to 100 parts of the polyethylene glycol with trimethoxysilyl group at one end obtained in Reference Example 2.
0 parts was added, and this was prepared into a 1% by weight acetone solution, and then 1% by weight of dibutyltin dilaurate was added to the solid content to obtain an antifogging agent. It was applied to a cleaned glass plate and treated to form a cured film.

The above-mentioned cured film is firmly adhered to the glass plate,
Even after being immersed in hot water at 70°C for 3 hours, it did not peel off from the glass plate.

Patent applicant: 8 Tokyo Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. It is characterized by consisting of a terminal functional polymer having an alkoxysilyl group at one or both ends of polyethylene glycol having a number average molecular weight of 200 to 100,000 via a hydrocarbon group or a sulfonyl hydrocarbon group. Anti-fog agent.