JP2006316134A - Ultraviolet light absorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new ultraviolet light absorbent excellent in absorbing property of ultraviolet light and heat resistance, compared with conventional ultraviolet light absorbents and having excellent compatibility to polymer materials. <P>SOLUTION: The ultraviolet light absorbent comprises an aromatic polyamide compound having a specific structure represented by the figure as a component for ultraviolet light absorbent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultraviolet absorber, and more particularly to an ultraviolet absorber made of an aromatic polyamide having a low polymerization degree.

  Polyolefin resins such as polyethylene and polypropylene, polycarbonate resins, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, styrene resins such as polystyrene and ABS, polyamide resins such as nylon and aramid, polyvinyl chloride, polyphenylene ether, Synthetic resins represented by polymethyl methacrylate and the like are widely used in various fields as various molded articles, fibers, films, and coating materials.

  However, it is known that a molded body composed only of the above synthetic resin causes quality deterioration such as discoloration and strength reduction when exposed to natural light, particularly ultraviolet light existing in natural light, and cannot be used for a long time. ing.

  In view of this, in these resin processed molded bodies, various types of ultraviolet absorbers have been conventionally used in order to prevent deterioration due to light (ultraviolet rays). For example, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, and salicylic acid compound ultraviolet absorbers are commonly used as ultraviolet absorbers for thermoplastic polymers.

  These conventional ultraviolet absorbers have an inherent ultraviolet absorbing ability at a certain wavelength at a relatively low temperature. However, these ultraviolet absorbers generally lack heat resistance, and when they are added to a polymer at a high temperature or are molded at a high temperature after the addition, problems of decomposition and sublimation often occur.

Furthermore, when these ultraviolet absorbers are added in a large amount to the polymer, phase separation occurs and the transparency and mechanical strength of the resin are lowered. Then, although addition of the ultraviolet absorber was stopped as much as possible, in that case, there was a problem that the light resistance of the resin could not be improved to a satisfactory level.
Therefore, in order to improve the light resistance of the resin processed molded body, an ultraviolet absorbent having a high ultraviolet absorbing ability is required by adding a small amount into the resin.

  Furthermore, among the resins, for example, aromatic polyamide is widely used as a heat-resistant polymer for molded articles because it has excellent thermal stability at high temperatures, shape retention, self-extinguishing properties, chemical resistance, and the like. . However, such aromatic polyamides are inferior in stability to light, and cause physical discoloration or coloring, molecular weight reduction, mechanical properties and the like due to light irradiation. This deterioration against light is remarkable compared to general organic polymer materials, and when exposed directly to sunlight, it causes significant deterioration in the short term, so clothing and interiors that are directly or indirectly exposed to light. Even when used as an interior material of a vehicle, there are significant restrictions.

  From such a viewpoint, attempts to improve the light resistance of aromatic polyamides have been proposed so far. For example, Japanese Patent Application Laid-Open No. 49-100322 proposes a method for improving light resistance by adding a benzotriazole ultraviolet absorber and an antioxidant. However, the degree of improvement in light resistance by this method is not always satisfactory. Further, JP-A-50-34344 also discloses a method of adding a piperidine derivative. In these methods, the added ultraviolet absorber is volatilized or decomposed by heat during the molding of the aromatic polyamide. However, there are problems such as gradual bleed out during use, and it cannot be said that the effect of improving light resistance over a long period of time is sufficient.

Japanese Patent Laid-Open No. 49-10032 Japanese Patent Laid-Open No. 50-34344

  The present invention has been made against the background of the above-described prior art, and its object is to provide a novel ultraviolet absorbent and heat resistance superior to conventional ultraviolet absorbents and excellent compatibility with polymer materials. It is to provide an ultraviolet absorber.

  As a result of intensive studies to solve the above problems, the present inventors have determined that a desired ultraviolet absorber can be obtained when an aromatic polyamide having a low polymerization degree is used as an ultraviolet absorber. Reached.

（上記式中、Ｒ^１及びＲ^２は末端官能基を有さないアリール基、炭素数１〜１０のアルキル基、水素原子又は互いに結合した環状体、Ｒ^３は水素原子、ハロゲン原子、アミノ基、ニトロ基、炭素数１〜１０のアルキル基、炭素数２〜８のアルコキシ基、炭素数２〜８のアシル基、炭素数２〜８のアシルオキシ基又は炭素数２〜８のアルコキシカルボニル基であり、ｍは０又は１〜４の整数、またｎは１〜２０の整数を表す。） That is, according to this invention, the ultraviolet absorber characterized by including the at least 1 sort (s) of aromatic polyamide compound chosen from the group which consists of the following general formula (I)-(III) is provided.

(In the above formula, R ¹ and R ² are an aryl group having no terminal functional group, an alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a cyclic group bonded to each other, R ³ is a hydrogen atom, a halogen atom, or an amino group. A nitro group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 2 to 8 carbon atoms, an acyl group having 2 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, or an alkoxycarbonyl group having 2 to 8 carbon atoms. And m represents 0 or an integer of 1 to 4, and n represents an integer of 1 to 20.)

  ADVANTAGE OF THE INVENTION According to this invention, the novel ultraviolet absorber which is excellent in the ultraviolet-ray absorption property and heat resistance, and has the outstanding compatibility with a polymeric material is provided.

  Hereinafter, embodiments of the present invention will be described in detail. The ultraviolet absorber of the present invention contains at least one aromatic polyamide compound selected from the group consisting of the above general formulas (I) to (III).

  In the above formula, specific examples of the alkyl group having 1 to 10 carbon atoms having no terminal functional group include methyl, ethyl, propyl, isopropyl, butyl, hexyl groups, etc., specific examples of the alkoxy group having 2 to 8 carbon atoms. Methoxy, ethoxy, propoxy, broxy, phenyloxy, etc., specific examples of the acyl group having 2 to 8 carbon atoms include acetyl, propionyl, benzoyl, etc., and specific examples of the acyl group having 2 to 8 carbon atoms include acetoxy. , Propionyloxy, benzoyloxy and the like, specific examples of the alkoxycarbonyl group having 2 to 8 carbon atoms include methoxycarbonyl, ethoxycarbonyl and the like.

Specific examples of the halogen atom include chlorine and bromine. Further, in the above-described general formula (I) ~ (III), it is necessary that R ¹ and R ² has no end group such as an amino group or a carboxyl group, a phenyl group or R ¹ and R ² mutually A bonded annular body is preferred.
Examples of the aryl group include aromatic groups having 6 to 12 carbon atoms, and specific examples include a phenyl group, a naphthyl group, and a biphenyl group.

Moreover, in said formula, m shows the integer of 0 or 1-4. Among them, m is preferably 0 or an integer of 1 to 2, and 0 or 1 is particularly preferable. When m is 2 or more, R ³ may be the same as or different from each other. N represents an integer of 1 to 20, and n is preferably an integer of 1 to 10. When n exceeds 20, the compatibility with the polymer is deteriorated and the light resistance improving effect is not exhibited.

The above compound polymerizes, for example, an anthranilamide derivative monomer obtained by reacting metaphenylenediamine and isatoic anhydride in the presence of a base catalyst with a meta-type aromatic dicarboxylic acid halide. At this time, for example, a monofunctional amine or acid halide having an alkyl chain or an aryl chain can be used as a terminal blocking agent.
Although there is no limitation in particular about the polymerization method, For example, it can manufacture by solution polymerization or interfacial polymerization.

  The ultraviolet absorbent according to the present invention thus obtained is effectively expressed as a light stabilizer by blending it with a polymer material. The polymer material used here is not particularly limited. For example, polyesters such as polyethylene terephthalate, polytetramethylene terephthalate, and polyethylene naphthalate, polyester / polyester having polyester and / or polyester as a soft segment. Polyolefin such as ether elastomer, polycarbonate, polyethylene, polypropylene, poly-4-methylpentene, polyolefin copolymer such as ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, chlorination Polyethylene, vinyl chloride / ethylene copolymer, vinyl chloride / vinyl acetate copolymer, vinyl chloride copolymer such as vinyl chloride / acrylic acid ester copolymer, nylon 6, nylon 11, nylon 12, nylon 66, polyamides such as aromatic polyamide, various styrene resins such as polystyrene, ABS resin, MBS resin, etc., thermoplastic resins such as polyvinyl acetate, polyacetal, polyurethane, polyphenylene oxide, polysulfone, polyarylate And thermosetting resins such as phenol resin, melamine resin, urea resin, epoxy resin, and unsaturated polyester resin. Among these, aromatic polyamides can be particularly preferably used. In the present invention, one kind of these synthetic resins may be used alone, or two or more kinds may be mixed and used.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each characteristic in an Example was evaluated in accordance with the following method.
(1) Ultraviolet Absorbance An N-methyl-2-pyrrolidone solution containing 25 ppm of an ultraviolet absorber was prepared, and this was used as a control cell with N-methyl-2-pyrrolidone at 250 ° C., 300 nm at 20 ° C. using a spectrophotometer. Absorbance at a wavelength of 350 nm was measured.
(2) Yellowness evaluation Using a Macbeth COLOR-EYE model M-2020PL manufactured by Macbeth Co., Ltd., the diffuse reflectance of the film for measurement was measured with a light source D65 and a 10-degree field of view. The lightness index L * value and the chromaticness index a *, b * value were calculated by arithmetic processing, and L * −b * was used as a measure of yellowing. It can be said that the higher the value, the higher the whiteness and the lower the yellowing.

(Synthesis of UV absorber A)
108 parts by weight of metaphenylenediamine was dissolved in 1000 parts by weight of dioxane, and 8 parts by weight of pyridine was added thereto. Further, 115 parts by weight of isatoic anhydride was added and reacted under reflux for 5 hours. After the reaction, 1000 parts by weight of ethanol was added to the reaction solution, and then allowed to stand at 0 ° C. for 12 hours. The precipitated white crystals were collected by filtration and further recrystallized with ethanol. The precipitated crystals were collected by filtration and dried at 100 ° C. for 6 hours to obtain an anthranilamide derivative monomer.

  Then, 25.6 parts by weight of isophthalic acid chloride was dissolved in 50 parts by weight of tetrahydrofuran (hereinafter referred to as THF) and cooled to -5 ° C. A solution dissolved in a portion of THF and cooled to −5 ° C. was added and reacted at −5 ° C. for 5 minutes.

  After the reaction, 400 parts by weight of water was added, and the precipitated white powder was collected by filtration and dried at 100 ° C. for 24 hours to obtain an ultraviolet absorber A having a structure represented by the following formula. The GPC chart of the obtained ultraviolet absorber A is shown in FIG.

[Example 1]
N-methyl-2-pyrrolidone cooled to −10 ° C. with 20 parts by weight of polymetaphenylene isophthalamide powder of IV = 1.9 produced by an interfacial polymerization method according to the method described in Japanese Patent Publication No. 47-10863 After suspending in 73 parts by weight to form a slurry, the solution was heated to 60 ° C. and dissolved to obtain a transparent polymer solution B.
Next, 1 part by weight of the ultraviolet absorber A was dissolved in 6 parts by weight of N-methyl-2-pyrrolidone, added to the polymer solution B, and stirred until uniform to obtain a transparent polymer solution C.

The obtained polymer solution C was subjected to stationary degassing at 60 ° C. for 30 minutes. These were cast on a glass plate using a doctor knife having a blade clearance of 100 μm. Next, the solvent was removed in water at 20 ° C. for 30 minutes, and the film was peeled off from the glass plate.
The obtained film surface was thoroughly wiped off and treated under hot air at 100 ° C. for 3 hours. Each of the obtained films was white with a thickness of 20 to 25 μm.

  An accelerated test by carbon arc irradiation was performed on yellowing of the obtained film by ultraviolet irradiation. Table 1 shows the values of L * -b * of the film before UV irradiation and L * -b * of the film after UV irradiation for 8 hours.

[Comparative Examples 1-4]
For comparison, a film manufactured by the same method as described above using only polymetaphenylene isophthalamide (Comparative Example 1) and a film manufactured by adding a benzotriazole-based ultraviolet absorber (manufactured by Ciba Geigy, Tinuvin 234) (Comparison) Example 2), a film manufactured by adding a benzophenone ultraviolet absorber (Asahi Denka, ADK STAB LA-51) (Comparative Example 3), a phenylbenzoate ultraviolet absorber (Kemipro Kasei, KEMISORB 112) The film (Comparative Example 4) was evaluated in the same manner as in Example 1.

  According to the present invention, since a novel ultraviolet absorber having excellent ultraviolet absorption and heat resistance and excellent compatibility with a polymer material is provided, the stability to light of a synthetic resin or the like is as much as possible. Can be improved.

The GPC chart which shows an example of the ultraviolet absorber of this invention.

Claims (1)

An ultraviolet absorber comprising at least one aromatic polyamide compound selected from the group consisting of the following general formulas (I) to (III):

(In the above formula, R ¹ and R ² are an aryl group having no terminal functional group, an alkyl group having 1 to 10 carbon atoms, a hydrogen atom or a cyclic group bonded to each other, R ³ is a hydrogen atom, a halogen atom, or an amino group. A nitro group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 2 to 8 carbon atoms, an acyl group having 2 to 8 carbon atoms, an acyloxy group having 2 to 8 carbon atoms, or an alkoxycarbonyl group having 2 to 8 carbon atoms. And m represents 0 or an integer of 1 to 4, and n represents an integer of 1 to 20.)

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