JPH0459768A - UV absorber - Google Patents

Abstract

NEW MATERIAL:A compound expressed by formula I (R1 is 1-5C straight-chain alkyl; R2 is 2-10C alkyl, provided that the total number of carbon atoms in R1 and R2 is >=5). EXAMPLE:2-{2'-Hydroxy-4'-(1'-ethylpentyl)oxyphenyl}benzotriazole. USE:An ultraviolet light absorber. PREPARATION:According to the reaction formulas, o-nitroaniline is diazotized and coupled with resorcin monoether according to a conventional method to provide a nitrazo compound expressed by formula II, which is then reduced to afford the objective compound expressed by formula I. The compound expressed by formula I is in the form of a liquid, excellent in miscibility with coatings and will not separate from the coatings during storage. After removing insoluble substances by distillation, etc., the aforementioned compound is miscible with photographic materials without or by using a small amount of a solvent.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a novel room temperature liquid ultraviolet absorber.

[Prior art]

It has been well known that ultraviolet absorbers made of 2-(2'-hydroxyphenyl)benzotriazoles are effective for various organic materials.

For example, Special Publication No. 38-7863 and Special Publication No. 42-
No. 4786 describes 2(resorcin)penzotriazo-
(m, p, 189-191℃) is
395 and JP-A-50-120486, 2[2'-hydroxy-4'-(β-phenoxyethoxy)phenyl]benzotriazole (m, p, 163
~165°C) is disclosed.

However, all of these 2-(2'-hydroxyphenyl)benzotriazoles are crystalline substances that have a high melting point and are solid at room temperature.

However, recently there has been an increasing demand for 2-(2'-hydroxyphenyl)benzotriazole ultraviolet absorbers that are liquid at room temperature.

〔the purpose〕

Therefore, the present invention provides a 2-(2'-hydroxyphenyl)benzotriazole ultraviolet absorbent that is liquid at room temperature.

〔composition〕

Therefore, as a result of intensive research, the inventors of the present invention found that 2-(
Surprisingly, among the 2'-hydroxyphenyl)benzotriazoles, there is a compound that is liquid at room temperature, and it was discovered that this compound also has excellent ultraviolet absorption ability, leading to the completion of the present invention. It is.

That is, the present invention provides the following method: -Sakatsu (wherein R□ is a straight chain alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and R2 is a straight chain or branched chain having 2 to 10 carbon atoms, preferably 3 to 6 carbon atoms. (However, the total number of carbon atoms of R1 and R2 is 5 or more.) Regarding the ultraviolet absorber contained.

The ultraviolet absorber of the present invention can be added to synthetic resins and synthetic rubbers to create stable compositions. Examples of these synthetic resins and synthetic rubbers include polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, polymethyl methacrylate, polyacrylonitrile, polyester, polyamide, polyurethane, unsaturated polyester, alkyd resin, thermosetting acrylic resin, and epoxy. resin, urea resin, melamine resin.

Examples include phenol resin, SBR, NBR, and the like.

Since the ultraviolet absorber of the present invention is liquid, it has good miscibility with paint and does not precipitate from paint during storage.

Further, the ultraviolet absorber of the present invention can be mixed into a photographic material without a solvent or with a small amount of solvent after removing insoluble matter by distillation or the like.

The ultraviolet absorbers of the present invention can be used alone or in combination of two or more.

Of course, the following conventionally known ultraviolet absorbers, antioxidants, light stabilizers, etc. can also be used in combination.

Examples of the ultraviolet absorber include: 2.4-dihydroxy-benzophenone 2-hydroxy-4-methoxybenzophenone 2-hydroxy-4-octoxybenzophenone 2-hydroxy-4-dobutyloxybenzophenone 2-hydroxy-4-benzyloxybenzophenone 2.2'-dihydroxy-4-methoxybenzophenone 2.2'4. Benzophenone UV absorbers such as 4'-tetohydroxybenzophenone, thiobisphenols such as, benzoaryazole UV absorbers such as UV absorbers such as phenyl salicylate, t-butylphenyl salicylate, etc.

Examples of antioxidants include 2,6-di-t-butyl-4-methylphenol 2-t
-butyl-4,6-dimethylphenol 2,6-dit
-Alkylphenols such as butyl-4-methoxyphenol, 2.6-di-tert-butyl-4-methoxyphenol2.
Examples include alkylated hydroquinones such as 5-di-t-butylhydroquinone, alkylidene bisphenols such as alkylidene bisphenols, and the like.

Also, stearyl-thiopropioamide, Antioxidants such as can also be used in combination.

Examples of the light stabilizer include 2,2'-thiobis-(4-octylphenol) rubiberidine.Next, synthesis examples of the compounds of the present invention are shown.

Synthesis example 1 Examples include hindered amines such as

Examples of other stabilizers include:

Nickel compounds such as

Furthermore, the ultraviolet absorber of the present invention can be used in combination with, for example, a plasticizer, an emulsifier, a lubricant, a pigment, a fluorescent brightener, a flame retardant, an antistatic agent, and the like.

(Left below) 0-Nitroaniline is diazotized and coupled with resorcinol monoether in a conventional manner to produce a nitroazo compound, which is reduced to give the object compound of the present invention.

Synthesis Example 2 0-Nitroaniline is diazotized and coupled with resorcin by a conventional method to obtain a nitroazo compound, which is reduced to 2-(2',4'-dihydroxyphenyl)benzotriazole, and 29 is converted into an ether. oxidizing agent (in the formula, X
represents an etherifying agent residue such as a halogen atom, alkyl or aryl sulfonate. ) are reacted to obtain one compound of interest of the present invention.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these in any way.

Example 1 45.4 g of methyl cellosolve (boxyphenyl)benzotriazole, 53.7 g of 3-bromoheptane, 1.0 g of potassium iodide, 22.8 g of potassium carbonate, 3.0 g of dimethylformamide
was charged, the temperature was raised to a reflux temperature of 105°C over 2 hours, and the reaction was further continued for 6 hours.

After the reaction is completed, methyl cellosolve is recovered and 20% of toluene is added.
0mQ. 100 mQ of water was added, and the pH was adjusted to 4 with dilute sulfuric acid.

Unreacted 2-(2',4'-dihydroxyphenyl)
The benzotriazole was filtered off.

The filtrate was separated and the toluene layer was washed with water. The toluene layer was rectified under reduced pressure to obtain 2-(2'-hydroxy-4'-(
1''-ethylbutyl)oxyphenyl)benzotriazole was obtained in a yield of 38 g.

237-b Examples 2-7 The compounds listed in the following table are prepared analogously to Example 1.

Examples Formula Physical Properties Example Formula The compound of Example 1 was used in an amount of 0.05% by weight based on polyvinyl chloride, and a film was prepared using a roll that could be easily mixed at 140°C.

Exposure was compared using a fade meter with one without the compound of Example 1, and as shown in the following table, it was clear that the compound of Example 1 was more stable.

Exposure time (h) Additive Example 9 0.05% by weight of the compound of Example 4 based on polypropylene (sample A), 0.05% by weight of bis-(2,2,6,6-titramethylpiperidyl) sebacate % (sample B), 0.025% of the compound of Example 4, bis-(2,
2,6,6-titramethylpiperidyl) sebacate o,
A test sheet was prepared at 180° C. for each sample (sample C) to which ozs% was added. A weather meter deterioration test was conducted by measuring the bending life.

Sample A without additives Sample B Sample C Bending life (h) Clearly, the compound of Example 4 stabilized the polypropylene compared to that without additives. Also.

It had a synergistic effect with bis-(2,2,6,6-titramethylpiperidyl) sebacate.

Example 10 0.0% of the compound of Example 6 was added to a transparent paint (polyurethane type).
After adding 2% by weight of new solvent without using it and stirring, it was exposed to ultraviolet light, and yellowing was clearly less than in the case where no solvent was added.

Similar tests were conducted on polyacrylic paints, but yellowing was almost reduced compared to those without the addition.

〔effect〕

According to the present invention, it was possible to provide a new type of benzotriazole ultraviolet absorber that is liquid at room temperature. Moreover, the ultraviolet absorber of the present invention has an ultraviolet absorbing ability that is at least superior to conventional ultraviolet absorbers that are solid at room temperature.

In addition, since the product of the present invention is liquid at room temperature, (a) it can be mixed uniformly with thermosetting resins that cannot be melt-mixed, and (b) residual particles may cause scratches and cause problems. It is extremely advantageous for stabilizing photographic film, etc.

(c) It is also convenient to use as a stabilizer for lacquers, paints, etc. without causing the problems (a) and (b).

July 25, 1990

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ 2-{2'-hydroxy-4'-(branched alkyl)oxyphenyl}benzotriazole represented by an alkyl group, provided that the total number of carbon atoms of R_1 and R_2 is 5 or more. 2. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1 is a straight chain alkyl group with 1 to 5 carbon atoms, R_2 is a straight chain or branched alkyl group with 2 to 10 carbon atoms. However, R_1 and R_2 have a total number of carbon atoms of 5 or more.) An ultraviolet absorber containing 2-{2'-hydroxy-4'-(branched alkyl)oxyphenyl}benzotriazole as an active ingredient.