JPH0959870A - Ultraviolet light absorbing polyester fiber structure and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester fiber structure by coating a polyester fiber with a specific ultraviolet light absorbing polymer-containing composition to form a middle layer and further coating the middle layer with an outermost layer, excellent in weather resistance. SOLUTION: A benzophenone derivative containing two or more phenolic hydroxyl groups of formula I (R1 is H or OH; R2 and R3 are each H, OH or OCn H2n+1 ; (n) is an integer of <=18; at least one of R1 and R2 is always OH) is reacted with a glycidyl group-containing (meth)acrylic acid ester of formula II ((m) is 0 or 1) to prepare a polymerizable ultraviolet light absorber. The ultraviolet light absorber is homopolymerized or copolymerized with another copolymerizable monomer to give an ultraviolet light polymer. A polymer composition selected from the group consisting of the polymer and a mixture of the polymer and an acrylic polymer and a mixture of the polymer and a polyester- based polymer is applied to a polyester fiber form a middle layer, to which an outermost layer composed of a weather-resisting agent-containing thermoplastic resin is laminated to give the objective ultraviolet light absorbing polyester fiber structure.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ultraviolet absorbing polyester fiber structure and a method for producing the same. More specifically, the present invention relates to an ultraviolet absorbing polyester fiber structure which has excellent weather resistance and can be preferably used for applications such as agricultural sheets exposed to sunlight, and a method for producing the same.

[0002]

2. Description of the Related Art Polyester fibers are widely used for clothing, industrial materials, etc. because they have high strength and high elastic modulus and excellent heat resistance and chemical resistance. Further, since polyester fibers have better light resistance than other fibers such as polyamide fibers, physical properties are less likely to deteriorate over time during practical use. Therefore, molded articles using polyester fibers are becoming more important in fields where high weather resistance is required. For example, a polyester fiber structure having a coating layer made of a thermoplastic resin composition is used for an agricultural sheet which is required to have both light transmittance and high weather resistance at the same time. However, when such an agricultural sheet is exposed to sunlight, not only the coating layer is deteriorated by ultraviolet rays, but also the polyester fiber itself is deteriorated by ultraviolet rays passing through the coating layer. As a result, the physical properties of the polyester fiber structure constituting the sheet are deteriorated, and the sheet strength required for practical use cannot be maintained.

The following methods are known as means for preventing the deterioration of the polyester fiber structure due to ultraviolet rays (that is, imparting weather resistance): (1) Not only the deterioration of the coating layer but also the polyester fiber A large amount of additives that prevent deterioration (for example, benzophenone-based and benzotriazole-based UV absorbers, hindered amine-based and hindered phenol-based antioxidants, phosphite-based heat stabilizers such as metal soaps) In a coating layer; (2) a method of spinning a polyester containing an additive (for example, a benzophenone-based or benzotriazole-based UV absorber) to impart a deterioration preventing function to the polyester fiber; and (3) The coating layer or polyester fiber contains a pigment such as carbon black to block ultraviolet rays. How to. However, each of these methods has the following problems.

The method (1) is disadvantageous in cost because it requires the use of a large amount of additives. Further, the additive may not be sufficiently mixed with the thermoplastic resin composition forming the coating layer, or the additive may discolor the polyester fiber structure. In the method (2), the spinnability or physical properties of the polyester fiber may deteriorate.
The method (3) cannot be applied to applications where light transmittance is required.

As described above, there is a demand for a polyester fiber structure which simultaneously satisfies both light transmittance and high weather resistance.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to have excellent weather resistance and sunlight such as an agricultural sheet. An object of the present invention is to provide an ultraviolet-absorbing polyester fiber structure that can be suitably used for applications exposed to the sun and a method for producing the same.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have made two layers of polyester fiber, an intermediate layer made of a specific ultraviolet absorbing polymer and an outermost layer made of a thermoplastic resin containing a weathering agent. It was found that the above object was achieved by forming it on the surface, and the present invention was completed.

The ultraviolet absorbing polyester fiber structure of the present invention is an ultraviolet absorbing polyester fiber structure having a polyester fiber, an intermediate layer covering the polyester fiber, and an outermost layer covering the intermediate layer. A polymer in which the intermediate layer contains an ultraviolet absorbing polymer selected from the group consisting of a homopolymer of a polymerizable ultraviolet absorber, and a copolymer of the polymerizable ultraviolet absorber and another copolymerizable monomer. A composition comprising the polymerizable ultraviolet absorber,

[0009]

Embedded image

(Where R ₁ is H or OH and R _{2 is}
And R ₃ are each independently H, OH or OC _n H
_{2n + 1} (n is an integer less than or equal to 18), and R ₁ ,
At least one of R ₂ and R ₃ is always OH), and a benzophenone derivative having two or more phenolic hydroxyl groups,

[0011]

[Chemical 6]

A thermoplastic resin containing a weathering agent, which is a reaction product of a (meth) acrylic acid ester having a glycidyl group represented by (where m is 0 or 1) Made of resin.

In a preferred embodiment, the polymeric composition is the dry residue of an aqueous emulsion.

In a preferred embodiment, the polymer composition is the above-mentioned UV-absorbing polymer, a mixture of the UV-absorbing polymer and an acrylic polymer, and the UV-absorbing polymer and a polyester-based composition. It is selected from the group consisting of mixtures with macromolecules.

The method of manufacturing the UV absorbing polyester fiber structure of the present invention includes the following steps:

[0016]

[Chemical 7]

(Where R ₁ is H or OH and R _{2 is}
And R ₃ are independently H, OH or OC _n H
_{2n + 1} (n is an integer less than or equal to 18), and R ₁ ,
At least one of R ₂ and R ₃ is always OH), and a benzophenone derivative having two or more phenolic hydroxyl groups,

[0018]

Embedded image

A step of reacting with a (meth) acrylic acid ester having a glycidyl group represented by (where m is 0 or 1) to prepare a polymerizable ultraviolet absorber; A step of preparing an ultraviolet absorbing polymer by polymerizing the absorber alone or by copolymerizing with another polymerizable monomer; a polymer composition containing the ultraviolet absorbing polymer, A step of applying the polyester fiber to the polyester fiber; and a step of coating the polyester fiber provided with the polymer composition with a thermoplastic resin containing a weathering agent.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Known polyesters can be used for the polyester fibers used in the ultraviolet absorbing polyester fiber structure of the present invention.

The polyester can be obtained, for example, by directly reacting a dicarboxylic acid with a glycol, transesterifying an alkyl ester of a dicarboxylic acid with a glycol and then polycondensing, or polycondensing a diglycol ester of a dicarboxylic acid. It can be manufactured by the method.

Examples of the dicarboxylic acid include aromatic compounds such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalene dicarboxylic acid, 5-sodium sulfoisophthalic acid, diphenyl ether 4,4'-dicarboxylic acid and diphenyldicarboxylic acid. Dicarboxylic acids; Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid and their ester forming properties Examples include derivatives.

Examples of glycols include ethylene glycol, trimethylene glycol, butanediol,
Hexamethylene glycol, diethylene glycol, cyclohexanedimethanol, neopentyl glycol,
1,3-propylene glycol and the like can be mentioned. In addition, polyalkylene glycols such as polyethylene glycol, polybutylene glycol, polypropylene glycol can also be used. In addition, aromatic diols such as hydroquinone, resorcin, 2,2-bis (di-hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane can also be used. These glycol components may be used alone or in combination of two or more.

Typical examples of preferable polyesters include:
Examples thereof include polyethylene terephthalate, polyethylene butylene terephthalate, and polyethylene-2,6-naphthalate.

A polyester fiber is obtained by spinning the above polyester by a known method. The polyester fiber can be molded into a desired shape and used. Typical forms include woven fabrics and knitted fabrics.

The intermediate layer of the ultraviolet absorbing polyester fiber structure of the present invention comprises a polymer composition containing an ultraviolet absorbing polymer, and the ultraviolet absorbing polymer is a homopolymer of a polymerizable ultraviolet absorber. , And a copolymer of the polymerizable ultraviolet absorber and another copolymerizable monomer. Such a polymer composition has a very excellent ultraviolet absorption ability.

The above-mentioned polymerizable ultraviolet absorber is

[0028]

Embedded image

(Where R ₁ is H or OH and R _{2 is}
And R ₃ are independently H, OH or OC _n H
_{2n + 1} (n is an integer less than or equal to 18), and R ₁ ,
At least one of R ₂ and R ₃ is always OH), and a benzophenone derivative having two or more phenolic hydroxyl groups,

[0030]

Embedded image

A reaction product with a (meth) acrylic acid ester having a glycidyl group represented by (where m is 0 or 1).

Specific examples of the benzophenone derivative include:
2,4-dihydroxybenzophenone, 2,2'-dihydroxybenzophenone, 2,2'-dihydroxy-
4,4'-dimethoxybenzophenone, 2,2 ', 4
4'-tetrahydroxybenzophenone, and 2,
2 ', 4-trihydroxybenzophenone is mentioned. As the (meth) acrylic acid ester having a glycidyl group, glycidyl acrylate and glycidyl methacrylate are particularly suitable. The benzophenone derivative and the (meth) acrylic acid ester are preferably 1.2 to 1.7 parts by weight, and more preferably 1.3 to 1.5 parts by weight of the benzophenone derivative with respect to 1 part by weight of the (meth) acrylic acid ester. The mixture is mixed in a proportion of parts by weight and used for the reaction.

A special anionic compound can be suitably used as a catalyst for the synthesis of the polymerizable ultraviolet absorber. Here, the special anionic compound is a compound in which hydrogen of at least one hydroxyl group of the benzophenone derivative is replaced with an alkali metal. This anionic compound can be easily obtained from the benzophenone derivative and the alkali metal hydroxide. Specific examples of alkali metals include lithium, sodium, and potassium. The alkali metal can be used in a ratio of preferably 0.025 to 0.25 mol, and more preferably 0.05 to 0.125 mol with respect to 1 mol of the benzophenone derivative. By using such a special anionic compound as a catalyst, it becomes possible to obtain a desired polymerizable ultraviolet absorber in a high yield without performing a complicated isolation or purification operation after the completion of the synthesis reaction. . In particular,
After the completion of the synthesis reaction, the desired polymerizable ultraviolet absorber can be obtained with a yield of almost 100% simply by neutralizing with concentrated hydrochloric acid and filtering out the precipitated alkali metal chloride. The polymerizable ultraviolet absorber thus obtained is a viscous oily compound.

The ultraviolet absorbing polymer is preferably
It is obtained by emulsion-polymerizing the above-mentioned polymerizable ultraviolet absorber in an aqueous medium. By carrying out emulsion polymerization in an aqueous medium, a UV-absorbing polymer can be obtained hygienically and safely. This is because there is no scattering of the organic solvent or the low molecular weight compound other than evaporation of water when the obtained polymer composition containing the ultraviolet absorbing polymer is applied to the polyester fiber.

The polymerizable ultraviolet absorber may be polymerized alone or may be copolymerized with a copolymerizable monomer. Examples of the copolymerizable monomer include ethyl acrylate, methyl methacrylate, n-butyl acrylate, hydroxyethyl methacrylate, dimethylamino methacrylate, diethylamino methacrylate, glycidyl methacrylate, glycidyl acrylate, acrylic acid, and methacrylic acid. To be The surface characteristics of the intermediate layer can be variously changed by appropriately changing the type of the copolymerizable monomer, the copolymerization molar ratio, and the like.

The conditions of emulsion polymerization are not particularly limited, but the monomer can be polymerized at a concentration of preferably 10 to 40 parts by weight, more preferably 20 to 30 parts by weight, based on 100 parts by weight of the aqueous medium. Here, the monomer means a polymerizable ultraviolet absorber when the polymerizable ultraviolet absorber is polymerized alone, and a polymerizable ultraviolet absorber when the polymerizable ultraviolet absorber is copolymerized with another copolymerizable monomer. It means a mixture of an agent and a copolymerizable monomer.

Further, when a copolymer is used as the ultraviolet absorbing polymer in the present invention, the relative amounts of the benzophenone derivative, the (meth) acrylic acid ester having a glycidyl group, and the copolymerizable monomer are: Depending on the intended use of the polyester fiber structure obtained, it is preferable to change it in the following range: That is, where X is a parameter representing the relative amount of the benzophenone derivative, X is preferably 0.10 to 0.75, and more preferably It is preferably 0.25 to 0.75. Here, X is represented by the following formula.

[0038]

[Equation 1]

When X is less than 0.10, the ultraviolet absorbing ability is insufficient. When X exceeds 0.75, the viscosity becomes too high, and therefore the operation during emulsion polymerization is often difficult.

Various additives may be added to the ultraviolet absorbing polymer thus obtained, depending on the intended use, to prepare a polymer composition having an ultraviolet absorbing ability. Examples of the additives include thickeners, pH adjusters, emulsifiers, antistatic agents and the like.

Preferably, the polymeric composition can be applied to polyester fibers as an aqueous emulsion. The solid content of the emulsion is preferably 5 to 60% by weight, more preferably 10 to 30% by weight. The amount of the polymer composition attached to the polyester fibers is preferably 0.1 to 10.0% by weight, and more preferably 0.5 to 5.0% by weight, based on the weight of the polyester fiber structure. . As a method for applying the polymer composition to the polyester fiber,
Known application methods can be used, and examples include dipping and coating. The polymer composition may be applied to the polyester fiber itself or a molded article (for example, a woven fabric) made of the polyester fiber.

Now, with reference to FIG. 1, the excellent ultraviolet absorbing ability of the polymer composition will be described. The light transmittance is very useful as a parameter representing the ultraviolet absorption ability. As an example in which the change in light transmittance is most clearly understood, the change in light transmittance of a film (that is, a polyester film) will be described. FIG. 1 is a graph showing the light transmittance in the short wavelength region in the case of using a polyester film alone and in the case of applying a polymer composition to a polyester film. As is clear from FIG. 1, by applying the polymer composition, almost no light having a wavelength of 320 nm or less, which is most harmful to polyester, is transmitted. That is, it can be seen that the application of the polymer composition markedly improves the ultraviolet ray cut rate. Incidentally, in practical use, the thickness of the outermost layer, the type and content of the weatherproofing agent contained in the outermost layer, the type of polymer composition and the imparted amount, etc. It can change.

The outermost layer of the ultraviolet absorbing polyester fiber structure of the present invention is a thermoplastic resin containing a weathering agent. As the thermoplastic resin, a known thermoplastic resin can be used, and examples thereof include vinyl resin, acrylic resin, fluororesin, silicone resin, and urethane resin. Polyvinyl chloride is particularly preferred. Examples of the weatherproofing agent include
Examples include benzophenone-based and benzotriazole-based ultraviolet absorbers, hindered amine-based and hindered phenol-based antioxidants, phosphite-based heat stabilizers such as metal soaps. The content of the weatherproofing agent changes depending on the application. As a preferred example, a 30/70 to 70/30 (weight ratio) mixture of an ultraviolet absorber and an antioxidant is preferably 0.1 to 20 parts by weight, more preferably 100 parts by weight of the thermoplastic resin. Is contained in an amount of 0.5 to 10 parts by weight.

As a method for coating the polyester fiber with the thermoplastic resin, a known method can be adopted, and examples thereof include dipping in a thermoplastic resin solution, dipping in a thermoplastic resin melt, and coating. The coating amount of the thermoplastic resin on the polyester fiber is preferably 1.0 to 3.0 with respect to the weight of the polyester fiber on which the intermediate layer is formed.
Times, and more preferably 1.5 to 2.5 times. The thermoplastic resin may cover the polyester fiber itself or a molded product (for example, a woven fabric) made of the polyester fiber.

The polyester fiber structure thus obtained has excellent weather resistance and can be suitably used for applications such as agricultural sheets, tents, etc. exposed to sunlight.

The operation will be described below.

The ultraviolet absorbing polyester fiber structure of the present invention has a polyester fiber, an intermediate layer covering the polyester fiber, and an outermost layer covering the intermediate layer. The ultraviolet absorbing polymer forming the intermediate layer is a specific polymer obtained from a reaction product of a benzophenone derivative and a (meth) acrylic acid ester having a glycidyl group,
It has a very good UV absorption capacity. Therefore, the intermediate layer is 320 nm which is particularly harmful for polyester fibers.
It acts as a screen that almost completely prevents transmission of shorter wavelength ultraviolet light. Further, since the thermoplastic resin forming the outermost layer contains a weather resistance agent, the weather resistance is remarkably improved by the synergistic effect of the intermediate layer and the outermost layer.

[0048]

EXAMPLES The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

Example 1 As shown in Table 1, 21.5 parts by weight of 2,4-dihydroxybenzophenone as a benzophenone derivative and glycidyl methacrylate 1 as a (meth) acrylic acid ester having a glycidyl group 1
By reacting with 7 parts by weight, a polymerizable ultraviolet absorber was prepared. At that time, a monosodium salt of 2,4-dihydroxybenzophenone was used as a catalyst. Next, 13 parts by weight of ethyl acrylate and 13 parts by weight of methyl methacrylate were added to the obtained polymerizable ultraviolet absorber to prepare a monomer mixture. (That is, the monomer mixture was prepared such that the parameter X representing the relative amount of the benzophenone derivative was 0.50.) With respect to 100 parts by weight of this monomer mixture, 300 parts by weight of water, 3 parts by weight of an emulsifier, and initiation of polymerization 1 part by weight of the agent was added and emulsion polymerization was carried out by a usual method to obtain an emulsion of ultraviolet absorbing polymer. The obtained emulsion was stable, and no abnormality such as formation of a precipitate was observed even after standing for several months. Next, to 395 parts by weight of this emulsion, 12 parts by weight of a thickener (Rohm and Haas Company, Primal ASE-60) and 193 parts by weight of water were added, and the pH was adjusted to 9 with aqueous ammonia, A coating liquid for forming an intermediate layer was prepared. The solid content of this coating liquid was 15% by weight.

On the other hand, a plain weave fabric having a weave density of 26 filaments / inch was prepared by using polyester fibers of 250 denier 48 filaments (breaking strength 8.0 g / d, breaking elongation 20%). This plain fabric was dipped in the coating liquid for forming the intermediate layer. The dipped plain woven fabric was squeezed with two mangles so that the amount of adhesion after drying was 1.0% by weight based on the weight of the polyester fiber structure, and dried at 110 ° C. for 3 minutes to form an intermediate layer. .

Dioctyl phthalate (DO
The polyvinyl chloride resin containing P) was melted at about 200 ° C. A benzotriazole-based UV absorber (Ciba Geigy, Tinuvin 1130) and a hindered phenolic antioxidant (Takamatsu Yushi Co., Ltd., Irganox 1330) were blended in a ratio of 1: 1 to this melt, The coating liquid for forming the outermost layer was added so that the content was 5% by weight. The soaked plain weave fabric was soaked that the weight ratio of the thermoplastic resin containing the weatherproofing agent to the plain weave fabric was 2.0 times.
The outermost layer was formed by squeezing with this mangle.

The polyester fiber structure obtained as described above was irradiated with a Sunshine Super Long Life Weather Meter (manufactured by Suga Test Instruments Co., Ltd.) for 300 hours. The black panel temperature at the time of irradiation was 63 ° C., and water was sprayed as a rain condition at a rate of 12 minutes for 60 minutes.

Tensile test according to JlS L 1096 6.1 (strip method) and JlS L 10
96 6.15.4 Tensile strength and tear strength of the polyester fiber structure after irradiation were measured by a tear test based on the C method (trapezoid method), and the retention rate of the tensile strength and the tear strength (tensile strength before irradiation And the tensile strength and the tear strength after irradiation when the tear strength was 100%) were used as indicators of weather resistance. Table 2 shows the results
Shown in

[0054]

[Table 1]

[0055]

[Table 2]

Example 2 A polyester fiber structure was obtained in the same manner as in Example 1 except that an ultraviolet absorbing polymer was prepared using the compounds shown in Table 1, and the polyester fiber structure was evaluated for weather resistance. Table 2 shows the evaluation results.

Example 3 A polyester fiber structure was obtained in the same manner as in Example 1 except that an ultraviolet absorbing polymer was prepared using the compounds shown in Table 1, and was subjected to weather resistance evaluation. Table 2 shows the evaluation results.

Comparative Example 1 A polyester fiber structure was obtained in the same manner as in Example 1 except that the intermediate layer was not formed and that the outermost layer contained no weathering agent. It provided for evaluation. Table 2 shows the evaluation results.

Comparative Example 2 A polyester fiber structure was obtained in the same manner as in Example 1 except that the intermediate layer was not formed, and was subjected to weather resistance evaluation. Table 2 shows the evaluation results.

Comparative Example 3 A polyester fiber structure was obtained in the same manner as in Example 2 except that the outermost layer contained no weathering agent, and was subjected to weather resistance evaluation. Table 2 shows the evaluation results.

As is clear from Table 2, the polyester fiber structures of the examples of the present invention have a tensile strength and tear strength retention of at least about 10 as compared with the comparative examples.
%, The weather resistance is remarkably improved. Furthermore, it can be seen that weather resistance is not sufficient if only one of the intermediate layer and the outermost layer is formed.

[0062]

According to the present invention, an ultraviolet absorbing polyester fiber structure having excellent weather resistance and a method for producing the same are provided. This ultraviolet absorbing polyester fiber structure can be suitably used for applications exposed to sunlight, such as agricultural sheets.

[Brief description of drawings]

FIG. 1 is a graph showing the light transmittance in a short wavelength region when a polyester film is used alone and when a polymer composition forming an intermediate layer of a polyester fiber structure of the present invention is applied to the polyester film. is there.

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Claims (4)

[Claims] 1. An ultraviolet absorbing polyester fiber structure having a polyester fiber, an intermediate layer covering the polyester fiber, and an outermost layer covering the intermediate layer, wherein the intermediate layer comprises a polymerizable ultraviolet absorber. A polymer composition containing a UV-absorbing polymer selected from the group consisting of a homopolymer and a copolymer of the polymerizable UV-absorbing agent and another copolymerizable monomer. The agent is (Where R ₁ is H or OH, R ₂ and R
₃ are each independently H, OH or OC _n H _{2n + 1} (n is an integer of 18 or less), and at least one of R ₁ , R ₂ and R ₃ is always OH). A benzophenone derivative having two or more phenolic hydroxyl groups, represented by: (Wherein m is 0 or 1), which is a reaction product with a (meth) acrylic acid ester having a glycidyl group, wherein the outermost layer is a thermoplastic resin containing a weathering agent. , UV absorbing polyester fiber structure. 2. The ultraviolet absorbing polyester fiber structure according to claim 1, wherein the polymer composition is a dry residue of an aqueous emulsion. 3. The polymer composition comprises the ultraviolet absorbing polymer, a mixture of the ultraviolet absorbing polymer and an acrylic polymer, and a mixture of the ultraviolet absorbing polymer and a polyester polymer. The ultraviolet-absorbing polyester fiber structure according to claim 1, which is selected from the group consisting of: 4. A method for producing a UV-absorbing polyester fiber structure comprising the steps of: (Where R ₁ is H or OH, R ₂ and R
₃ are independently H, OH or OC _n H _{2n + 1} (n is 18
A benzophenone derivative having two or more phenolic hydroxyl groups represented by the following integer) and at least one of R ₁ , R ₂ and R ₃ is always OH: A step of reacting with a (meth) acrylic acid ester having a glycidyl group represented by (where m is 0 or 1) to prepare a polymerizable ultraviolet absorber, A step of preparing an ultraviolet-absorbing polymer by polymerizing alone or by copolymerizing with another polymerizable monomer; a polymer composition containing the ultraviolet-absorbing polymer is added to a polyester fiber. The step of applying, and the step of coating the polyester fiber provided with the polymer composition with a thermoplastic resin containing a weathering agent.