KR0143137B1 - Low density polyethylene film - Google Patents

Abstract

The present invention provides a low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) 90:10

To 100 parts by weight of the resin obtained by mixing at a weight ratio of -50: 50,

0.2 to 0.7 parts by weight of a benzotriazole-based ultraviolet absorbent represented by the formula (wherein X is hydrogen or chlorine; R 1 is a straight or branched chain alkyl group having 1 to 8 carbon atoms; R 2 is a hydrogen or branched chain alkyl group);

(Wherein R3 is a straight or branched chain alkyl group having 1 to 8 carbon atoms) of 0.1 to 0.3 parts by weight of the benzoate-based ultraviolet absorber, provided that the total amount of these two ultraviolet absorbers is 0.3 to 1 part by weight; 0 to 0.2 parts by weight of a hindered amine UV stabilizer is added, melt mixed, and extruded to provide an ultraviolet ray shielding low density polyethylene film.

The film produced by the method of the present invention exhibits excellent UV protection, weather resistance, impact resistance, permeability and strength.

Description

Sunscreen Low Density Polyethylene Film

1 is a benzotriazole UV absorber (0.4 parts by weight) and a hindered amine UV stabilizer (0.2 parts by weight) are added to 100 parts by weight of a resin obtained by mixing a low density polyethylene and ethylene vinyl acetate in a weight ratio of 80:20. It is a graph which compared the case where an additive type ultraviolet absorber is added (No2, 0.2 weight part) and the case where it is not added (No1).

The present invention relates to a sunscreen low density polyethylene film, and more particularly, to a resin obtained by mixing low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) at a predetermined ratio, a benzotriazole ultraviolet absorber and a benzoate ultraviolet absorber. And a sunscreen low density polyethylene film prepared by adding a hindered amine ultraviolet stabilizer, melt-mixing, and extruding as necessary.

Conventionally, ultraviolet ray-blocking low density polyethylene films that block ultraviolet rays of 400 nm or less that adversely affect the human body and living organisms are known, but these conventional films not only sufficiently block ultraviolet rays but also with time. The surface is clouded and the visible light transmittance is reduced, and due to the washing action of the film surface during climate change such as snow, rain, dew, etc., the concentration of the ultraviolet absorber and the stabilizer is diluted, resulting in a decrease in the UV blocking performance.

On the other hand, Japanese Patent Publication No. Hei 4-55217 discloses a resin film containing a benzotriazole-based ultraviolet absorber in a polyethylene resin having a maximum UV blocking rate and a light transmittance of 60% or more. However, this film has excellent UV blocking rate but low light transmittance of about 60%, and a large amount of ultraviolet absorber should be added to obtain desired UV blocking effect (e.g. blocking 60% of UV rays at 290nm). In order to add 1 part by weight of the ultraviolet absorber), there is a problem that the transition of the additives in the final resin film occurs.

It is an object of the present invention to mix low-density polyethylene and ethylene vinyl acetate, which are general purpose resins, to protect exposures in areas of high exposure to UV light, for example to protect exposed skin when sunbathing on the beach and to protect crops in the house. By producing a film using a resin, a film having a thickness of 30 to 200 µm capable of absorbing 80% or more of ultraviolet rays of 400 nm or less and transmitting 70% or more of visible light of 400 nm or more is produced. It is to provide a low density polyethylene film that is excellent in blocking ultraviolet rays.

In order to achieve the above object, the present invention relates to 100 parts by weight of a resin obtained by mixing a low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) in a weight ratio of 90:10 to 50:50,

0.2 to 0.7 parts by weight of a benzotriazole ultraviolet absorber represented by the above formula (X) wherein X is hydrogen or chlorine; R 1 is a straight or branched chain alkyl group having 1 to 8 carbon atoms; R 2 is a hydrogen or branched chain alkyl group;

(Wherein R3 is a straight or branched chain alkyl group having 1 to 8 carbon atoms) of 0.1 to 0.3 parts by weight of the benzoate-based ultraviolet absorber, provided that the total amount of these two ultraviolet absorbers is 0.3 to 1 part by weight; 0 to 0.2 parts by weight of a hindered amine UV stabilizer is added, melt mixed, and extruded to provide an ultraviolet ray shielding low density polyethylene film.

In the present invention, low density polyethylene and ethylene vinyl acetate in a weight ratio of 90:10 to 50:50; Preferably, resin obtained by mixing 80:20 to 60:40 is used as a base material. As the ethylene vinyl acetate content in the resin used as the substrate increases, the tensile strength and elongation of the film are improved. In addition, as the content of ethylene vinyl acetate increases, the transferability of the additive may be reduced to achieve desired properties, but when it exceeds 50 parts by weight, the frictional force of the resulting film surface increases, resulting in poor moldability.

UV-resistant low-density polyethylene film according to the present invention in the resin (based on 100 parts by weight), 0.2 to 0.7 parts by weight of benzotriazole-based ultraviolet absorber, 0.1 to 0.3 parts by weight of benzoate-based (but the total amount of these two ultraviolet absorbers Is 0.3 to 1.0 part by weight) and 0 to 0.2 part by weight of the hindered amine ultraviolet stabilizer. When the resin film of the present invention contains an excessive amount of the benzotriazole-based ultraviolet absorber and the benzoate-based ultraviolet absorber, the initial ultraviolet ray blocking performance is excellent, but as the time passes, the performance of the additive is caused to cause the blocking rate to drop. Hindered amine UV stabilizers are added to reinforce the weather resistance (may not be added in some cases). When these stabilizers are contained in excess, the weather resistance of the film is improved, but the transparency of the resin film is reduced. do.

The benzotriazole ultraviolet absorbers used in the present invention include 2- (2'-hydroxy-3'5'-di-tert-butylphenyl) -5-chlorobenzotriazole and 2- (2'-hydroxy- 3 ', 5'-diisobutylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isopropyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- ( 2'-hydroxy-3'-isopropyl-5'-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isopropyl-5'-octylphenyl) -5- Chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-isobutyl-5 ' -Propylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy -3'-tert-butyl-5'-isopropylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-isooctylphenyl) -5 -Chlorobenzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-3 -Butylphenyl) benzotriazole, and the like, and among these, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole and 2- (2'- Hydroxy-3 ', 5'-di-tert-butylphenyl) -5-benzotriazole and the like are preferable. These benzotriazole type ultraviolet absorbers show the excellent ultraviolet absorbing effect in the ultraviolet range of 280-390 nm.

The benzoate-based ultraviolet absorbers used in the present invention include 2-3-butyl-4-methylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate and 2-3-butyl- 4-Ethylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3 tert-butyl-4-propylphenyl-3', 5'-di-tert-butyl -4'-hydroxybenzoate, 2-3 tert-butyl-4-isopropylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3 tert-butyl- 4-butylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3 tert-butyl-4-isobutylphenyl-3', 5'-di-tert- Butyl-4'-hydroxybenzoate, 2,4-di-tert-butylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3-butyl- 4-hexylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3 tert-butyl-4-isohexylphenyl-3', 5'-di-tert- Butyl-4'-hydroxybenzoate, 2-3 tert-butyl-4-heptylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3 tert-butyl- 4-isoheptylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybene , Tert-butyl-4-octylphenyl-3 ', 5'-di-tert-butyl-4'-hydroxybenzoate, tert-butyl-4-isooctylphenyl-3' , 5'-di-tert-butyl-4'-hydroxybenzoate, 2-3-butyl-4-tert-octylphenyl-3 ', 5'-di-tert-butyl-4'- Hydroxybenzoate and the like. These benzoate-based ultraviolet absorbers exhibit excellent ultraviolet absorbing effects in the ultraviolet region of 250 to 300 nm.

The hindered amine ultraviolet stabilizers used in the present invention are poly- (N, β-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidylsuccinate), bis-2, 2,6,6-tetramethyl-4-piperidyl sebacate, poly- {6-[(1,1,3,3-tetramethylbutyl) -imino] -hexamethylene- [4- (2, 2,6,6-tetramethylpiperidyl) -imino]} and the like. These hindered amine ultraviolet stabilizers have the effect of further enhancing weather resistance.

In the present invention, the low density polyethylene has a density of 0.90 to 0.94 g / cm 2, preferably 0.91 to 0.926 g / cm 3, and a melt index of 0.1 to 10 g / 10 minutes, preferably 0.1 to 5 g / 10 minutes. .

The ethylene vinyl acetate copolymer (EVA) used in the present invention is a thermoplastic material produced by copolymerizing ethylene and vinyl acetate under high pressure, and contains 5 to 33 parts by weight of vinyl acetate, and preferably has a melt index of 0.1 to 300 g / 10 minutes. .

The molding processing method and test method of the film of this invention are described. The film is prepared by an inflation extrusion process under the condition that the temperature of C3 of the extruder is 190 ° C and the die temperature is 190 ° C. In the ultraviolet ray screening test of the present invention, a wavelength range of 200 to 400 nm is investigated by using an ultraviolet-visible spectrometer (UV-VIS RECORDING SPECTROMETER), which is a model of UV-2100S manufactured by Shimadzu, Japan. Measure the average transmittance of. In addition, the blocking rate is calculated by substituting the following formula.

Block rate = 100-transmittance

The UV exposure test of the present invention was carried out using an ATLAS UV-CON under a B-type UV lamp at a UV irradiation temperature of 60 ° C. and a condensation temperature of 40 ° C. for 4 hours. , Cloudiness, tensile strength, elongation, etc. are measured. In the cloudiness test of the present invention, the elongation retention ratio, which is the elongation of the specimen at 200 hours of UV exposure to the elongation at 0 hours of UV exposure, that is, the specimen which is not exposed to ultraviolet rays manufactured by YASUDA SEIKI, Japan, is as follows. Measured by the equation.

Similarly, tensile strength retention is measured by the following equation.

In this case, the tensile strength test is measured under the conditions of ASTM D-882 using an Instron UTM 4502 model.

Next, the Example of this invention is described. However, these examples are provided only to facilitate understanding of the present invention, and the present invention is not limited to these examples.

Examples 1 to 5

Low density polyethylene (Hyundai Techren BF300) with a melt index of 0.8 g / 10 min, density of 0.921 g / cm 3, ethylene with a melt index of 1.5 g / 10 min, density of 0.934 g / cm 3 and 15 parts by weight of vinyl acetate To 100 parts by weight of a resin obtained by mixing vinyl acetate (Hyundai Techren EF440) in a weight ratio of 90:10 to 50:50, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl as an ultraviolet absorber 0.4 parts by weight of) -5-chlorobenzotriazole and 0.2 parts by weight of 2,4-di-tert-butylphenyl-4'-hydroxybenzoate; Poly- {6-[(1,1,3,3-tetramethylbutyl) -imino]}-hexamethylene- [4- (2,2,6,6-tetramethylpiperidyl)-UV stabilizer Imino] 0.2 parts by weight was added, melted and mixed. Subsequently, the film was extruded by an expansion extrusion method at a temperature of 190 ° C. and a die temperature of 190 ° C. of an extruder to form a film having a thickness of 80 to 90 μm. The results are shown in Table 1 below.

Comparative Examples 1-2

Low density polyethylene (Hyundai Techren BF300) with a melt index of 0.8 g / 10 min, density of 0.921 g / cm 3, ethylene with a melt index of 1.5 g / 10 min, density of 0.934 g / cm 3 and 15 parts by weight of vinyl acetate Additives added to 100 parts by weight of the resin obtained by mixing vinyl acetate (Hyundai Techren EF440) in a weight ratio of 100: 0 and 40:60 were added in the amounts shown in Table 1 below and molded in the same manner as in Examples 1-5. . The results are shown in Table 1 below.

Examples 6-10

Low density polyethylene (Hyundai Techren BF300) with a melt index of 0.8 g / 10 min, density of 0.921 g / cm 3, ethylene with a melt index of 1.5 g / 10 min, density of 0.934 g / cm 3 and 15 parts by weight of vinyl acetate To 100 parts by weight of a resin obtained by mixing vinyl acetate (Hyundai Techren EF440) at a weight ratio of 80:20, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5- which is an ultraviolet absorber. Chlorobenzotriazole, 2,4-di-tert-butylphenyl-4'-hydroxybenzoate and UV stabilizer poly- {6-[(1,1,3,3-tetramethylbutyl) -imino ] -Hexamethylene- [4- (2,2,6,6-tetramethylpiperidyl) -imino]} was added in the amounts shown in Table 2 below and molded in the same manner as in Examples 1-5. . The results are shown in Table 2 below.

Comparative Examples 3 to 4

2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole and 2,4-di-tertiary which are ultraviolet absorbents in the same resins as Examples 6 to 10 -Butylphenyl-4'-hydroxybenzoate and UV-stabilizing poly- {6-[(1,1,3,3-tetramethylbutyl) -imino] -hexamethylene- [4- (2,2, 6,6-tetramethylpiperidyl) -imino]} was added in the amounts shown in Table 2 below and molded in the same manner as in Examples 1 to 5. The results are shown in Table 2 below.

Examples 11-13

Low density polyethylene (Hyundai Techren BF300) with a melt index of 0.8g / 10min, density of 0.921g / cm3, 1.5g / 10min of melt index, density of 0.934g / cm2 and 15 parts by weight of vinyl acetate 100 parts by weight of a resin obtained by mixing ethylene vinyl acetate (Hyundai Techren EF440) at a weight ratio of 80:20 to 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5 as an ultraviolet absorber. -Chlorobenzotriazole, 2,4-di-tert-butylphenyl-4'-hydroxybenzoate, and UV-stabilizing poly- {6-[(1,1,3,3-tetramethylbutyl)- No] -hexamethylene- [4- (2,2,6,6-tetramethylpiperidyl) -imino]} was added in the amounts shown in Table 3 below and molded in the same manner as in Examples 1-5. It was. The results are shown in Table 3 below.

Comparative Example 5

Low density polyethylene (Hyundai Techren BF300) with a melt index of 0.8 g / 10 min, density of 0.921 g / cm 3, ethylene with a melt index of 1.5 g / 10 min, density of 0.934 g / cm 3 and 15 parts by weight of vinyl acetate Additives added to 100 parts by weight of the resin obtained by mixing vinyl acetate (Hyundai Techren EF440) in a weight ratio of 80:20 were added in the amounts shown in Table 3 below and molded in the same manner as in Examples 1 to 5. The results are shown in Table 3 below.

Claims (4)

To 100 parts by weight of resin obtained by mixing a low density polyethylene (LDPE) and ethylene vinyl acetate (EVA) in a weight ratio of 90:10 to 50:50, 0.2 to 0.7 parts by weight of a benzotriazole ultraviolet absorber represented by the above formula (X) wherein X is hydrogen or chlorine; R 1 is a straight or branched chain alkyl group having 1 to 8 carbon atoms; R 2 is a hydrogen or branched chain alkyl group; (Wherein R3 is a straight or branched chain alkyl group having 1 to 8 carbon atoms) of 0.1 to 0.3 parts by weight of the benzoate-based ultraviolet absorber, provided that the total amount of these two ultraviolet absorbers is 0.3 to 1 part by weight; A sunscreen low density polyethylene film prepared by adding 0 to 0.2 parts by weight of a hindered amine UV stabilizer, melt-mixing, and extruding. The sunscreen low density polyethylene film according to claim 1, wherein X is hydrogen or chlorine, and R1 is methyl, isopropyl, butyl, isobutyl, tert-butyl, octyl, isooctyl. . A compound according to claim 1, wherein in formula (II), R ₃ is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, isohexyl, heptyl, isoheptyl, isooctyl, 3 A sunscreen low density polyethylene film, characterized in that it is tea-octyl. The method of claim 1, wherein the hindered amine stabilizer is poly- (N, β-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidylsuccinate), bis- 2,2,6,6-tetramethyl-4-piperidyl sebacate, poly- {6-[(1,1,3,3-tetramethylbutyl) -imino] -hexamethylene- [4- ( 2,2,6,6-tetramethylpiperidyl) -imino]}.