JPH08870B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EVOH), a phenylbenzotriazole derivative (B) and bis (2,2,6,6). -Tetramethyl-4-piperidyl) sebacate (C) -containing EVOH resin composition having very good weather resistance.

B. Conventional Technology EVOH is a useful polymer material that has gas barrier properties and high transparency, and is excellent in oil resistance and aroma retention, and is widely used in films, sheets, containers and the like. However, if EVOH is exposed to sunlight or ultraviolet rays for a long time, it may deteriorate. It is known to compound various compounds such as salicylic acid ester-based compounds, benzophenone-based compounds, benzotriazole-based compounds, and nickel chelate-based compounds as stabilizers for resins such as polyolefins. Among the characteristics required as a photodeterioration inhibitor, the main items are (1) that the photodegradation inhibitor itself has excellent light stability, (2) that it can withstand high temperatures during molding, (3). It should be melted at the molding temperature and evenly dispersed in the resin so that the appearance of the resulting molded product is not impaired, and (4) no bleed-out occurs. No deterioration inhibitor has been found.

C. PROBLEMS TO BE SOLVED BY THE INVENTION The present invention is to obtain an EVOH composition which is extremely stable against deterioration by light, especially ultraviolet rays, and which can provide a molded article having excellent transparency and hue.

D. Means for solving problems EVOH (A) general formula A phenylbenzotriazole derivative (B) represented by
(Wherein R is a t-amyl group or a methylbenzyl group), and EVOH containing a specific amount of a mixture of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (C).
It is a resin composition.

E. More Detailed Description of the Invention In the present invention, EVOH is a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, preferably 25 to 55 mol%, and acetic acid of the copolymer. A vinyl component having a saponification degree of 90% or more is suitable. When the ethylene content is less than 20 mol%, not only the water resistance and hot water resistance of the molded article are deteriorated, but also EVOH itself tends to gel, and the effect of the present invention is difficult to be exhibited. Also, the ethylene content exceeds 60 mol% or the saponification degree is 90
If it is less than%, the original barrier performance of EVOH is deteriorated. Further, other comonomer may be copolymerized with this EVOH within a range not impairing the object of the present invention. In the present invention, when (B) and (C) are blended with EVOH (B) /
It is necessary that the weight ratio of (C) is 1/9 to 9/1, preferably 1/4 to 4/1. It is also necessary that the mixture of (B) and (C) be contained in EVOH in an amount of 0.1 to 2% by weight, preferably 0.15 to 1% by weight. If it is less than 0.1% by weight, the effect of the present invention is not exhibited. Two
If it is more than 10% by weight, the appearance of the obtained molded product becomes poor.

The blending method of EVOH with (B) and (C) in the present invention includes a method such as melt blending with a single-screw or twin-screw extruder. The blend is preferably pelletized once and then molded. When molded as it is without pelletization, the dispersion of the blended product is poor, and the desired weather-resistant molded product (for example, a film) may not be obtained. As another blending method, it is also preferable to blend a stabilizer with a solution of EVOH. This blend can be formed into a molded product by melt molding, extrusion molding, coating with a solution, or the like. Here, the molded product is a film, a sheet, a tube, a bottle, a cup, or the like.

A molded article obtained by blending EVOH with a mixture of a phenylbenzotriazole derivative (B) and bis (2,2,6,6-tetramethyl-4-piperidyl) sepacate (C) is resistant to deterioration of light, especially UV rays. It is surprising that it is not only extremely stable and extremely excellent in transparency and hue. In addition, one of the features of this mixture is that it does not impair the excellent gas barrier properties inherent in EVOH. In addition, since (B) and (C) do not bleed out, the surface is less contaminated, and the above effects are less deteriorated over time.

It is often preferable to use the resin composition of the present invention in the form of a laminate. At this time, the resin composition of the present invention is an intermediate layer,
It can be used as either the outermost layer or the innermost layer.
The resin to be laminated with the resin composition of the present invention is not particularly limited, but generally a resin having good transparency is preferable, for example, low density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, Polyolefin such as polybute, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, copolymer mainly composed of olefin such as ionomer, polyethylene terephthalate, polycarbonate, polyamide, polystyrene, polyvinyl chloride and the like. .

When the interlayer adhesion between these resins and the resin composition of the present invention is not sufficient, it is preferable to provide an adhesive resin layer. The adhesive resin is not particularly limited as long as it does not cause delamination at a practical stage, but is preferably a polyolefin-based polymer such as polyethylene, ethylene-vinyl acetate copolymer (vinyl acetate content 45
(Wt% or less), ethylene-acrylic acid ester or methacrylic acid ester copolymer (acrylic acid ester or methacrylic acid ester content 45 wt% or less) chemically (for example, ethylenically unsaturated carboxylic acid or anhydride thereof) A modified polyolefin-based copolymer obtained by bonding (by addition reaction or graft reaction) is used. It is also possible to blend these adhesive resins in either of the two layers or both layers instead of providing the adhesive resin between the layers.

The resin composition of the present invention can be formed into a film, a sheet, a tube, a bottle or the like as a laminate, and the thickness constitution of each layer is not particularly limited, but the resin composition of the present invention has a transparency of 300μ. It is preferably used in the following thickness, more preferably 200 μm or less.

The method for laminating the resin composition of the present invention is not particularly limited, and examples thereof include a coextrusion method, an extrusion lamination method, and a dry lamination method. Particularly, the coextrusion method is suitable because the characteristics of the resin of the present invention can be exhibited. is there.

The single-layer molded product or laminate obtained from the resin composition of the present invention has excellent photodeterioration-preventing properties and gas barrier properties, and since the resin composition layer is also excellent in transparency and hue, it can be used only as various foods. It is also effectively used as a medical container, agrochemical container, etc.

The present invention will be further described with reference to examples. Unless otherwise specified,% in the examples indicates% by weight.

F. Example Example 1 and Comparative Example 1 Ethylene content 31 mol%, saponification degree 99.4 mol%, melt index 3.8 g / 10 min (190 ° C., load 2160 g condition)
EVOH pellets 99.5%, 2- (3,5-di-t-amyl-
2-hydroxyphenyl) benzotriazole 0.1
%, Bis (2,2,6,6-tetramethyl-4-piperidyl)
Sebacate 0.4% was blended and pelletized in a twin screw extruder. The blended pellets were formed into a film with a T-die extruder to obtain a 30 μ film. This film had good transparency and good appearance. Fade irradiation of this film (weather meter, Shimadzu XW-60V3, light source 6
kw xenon lamp) After 1000 hrs, the breaking elongation was measured by a tensile tester. The elongation at break was 200%. This film is also used as an adhesive for dry laminating (AD-9 manufactured by Toyo Morton Co., Ltd.
00 / AD-RT-5) was used to laminate with a 50μ LDPE film. The oxygen gas permeability coefficient of this laminated film was measured by an oxygen gas barrier measuring device (OXTRAN-100 manufactured by MOCON). The oxygen gas permeability coefficient was 0.3 cc / m ² atm day (20 ℃ × 65% RH).

As a control, ethylene content 31 mol%, saponification degree 99.4
Mol%, melt index 3.8g / 10min (190 ℃, weight 21
EVOH pellets (under 60 g) were formed into a film by a T-die extruder to obtain a 30 μ film. This film was subjected to fade irradiation (weather meter, Shimadzu XW-60V3, light source 6 kw xenon lamp) for 1000 hrs, and the breaking elongation was measured with a tensile tester. The breaking elongation was 20%. This film is also used as an adhesive for dry laminating (AD-900 / AD-TR-
5) was used and laminated with a 50 μ LDPE film. The oxygen gas permeability coefficient of this laminated film was measured by an oxygen gas barrier measuring device (OXTRAN-100 manufactured by MOCON). The oxygen gas permeability coefficient was 0.3 cc / m ² atm day (20 ℃ × 65% RH).

Example 2 and Comparative Example 2 Ethylene content 48 mol%, saponification degree 99.5 mol%, melt index 5.5 g / 10 min (190 ° C, weighted 2160 g condition)
EVOH pellets 99.2%, 2- [2-hydroxy-3,5bis (α, α-dimethylbenzyl) phenyl] benzotriazole 0.4%, bis (2,2,6,6-tetramethyl-4-piperidyl) Sebacate 0.4% was blended and pelletized in a twin screw extruder. This blend pellet is
The film was formed into a film with a die extruder to obtain a 30 μ film.
This film had good transparency and good appearance. This film was subjected to fade irradiation in the same manner as in Example 1 and the breaking elongation was measured by a tensile tester. The breaking elongation was 220%. Further, this film was laminated with an LDPE film having a thickness of 50 μm in the same manner as in Example 1. The oxygen gas permeation coefficient of this laminated film was 0.3 cc / m ² atm day (20 ° C. × 65% RH).

As a control example, ethylene content 48 mol%, saponification degree 99.5
Mol%, melt index 5.5g / 10 minutes (190 ℃, weight 21
EVOH pellets (under 60 g) 96.0%, 2- [2-hydroxy-3,5bis (α, α-dimethylbenzyl) phenyl] benzotriazole 2.0%, bis (2,2,6,6-tetramethyl-) 2.0% of 4-piperidyl) sebacate was blended and pelletized in a twin screw extruder. The blended pellets were formed into a film with a T-die extruder to obtain a 30 μ film. This film was perforated and had a poor appearance.

Example 3 and Comparative Example 3 Ethylene content 44 mol%, saponification degree 99.5 mol%, melt index 5.0 g / 10 min (190 ° C., load 2160 g condition)
EVOH pellets 99.2%, 2- [2-hydroxy-3,5bis (α, α-dimethylbenzyl) phenyl] benzotriazole 0.7%, bis (2,2,6,6-tetramethyl-4-piperidyl) Sebacate 0.1% was blended and pelletized in a twin screw extruder. This blend pellet is
The film was formed into a film with a die extruder to obtain a 30 μ film.
This film had good transparency and good appearance. This film was subjected to fade irradiation in the same manner as in Example 1 and the breaking elongation was measured by a tensile tester. Breaking elongation Breaking elongation is 240%
Met.

As a control example, ethylene content 48 mol%, saponification degree 99.5
Mol%, melt index 5.5g / 10 minutes (190 ℃, weight 21
Under 60 g conditions) EVOH pellets 99.95%, 2- [2-hydroxy-3,5bis (α, α-dimethylbenzyl) phenyl] benzotriazole 0.02%, bis (2,2,6,6-tetramethyl-) 0.03% of 4-piperidyl) sebacate was blended and pelletized in a twin screw extruder. The blended pellets were formed into a film with a T-die extruder to obtain a 30 μ film. This film was subjected to fade irradiation in the same manner as in Example 1 and the breaking elongation was measured by a tensile tester. The breaking elongation was 30%.

G. Effect of the invention The molded product obtained by the resin composition of the present invention is not only stable against deterioration of light, especially ultraviolet rays, but also excellent in transparency, color layer, and gas barrier property,
Moreover, there is little deterioration with time of these effects.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08K 5: 3475)

Claims (1)

[Claims] 1. An ethylene content of 20 to 60 mol% and a saponification degree of 90%.
Above saponified ethylene-vinyl acetate copolymer (A)
, The general formula A phenylbenzotriazole derivative (B) represented by
(Wherein R is a t-amyl group or a methylbenzyl group) and bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (C) (B) / (C) in a weight ratio of 1 / 9
A resin composition containing 0.1 to 2% by weight of a mixture compounded to be 9/1.