JPH06313074A - Transparent and slippery ethylene-vinyl acetate copolymer film - Google Patents

Abstract

PURPOSE:To obtain the subject film having transparency and slipperiness, exhibiting high antiblocking property and useful as a film for vacuum sealed process by adding a metallic soap together with a higher fatty acid amide to an ethylene-vinyl acetate copolymer. CONSTITUTION:This film is produced by incorporating (A) an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10-25% and a melt index of 0.1-10g/10min with (B) 0.01-0.5wt.% of a higher fatty acid amide having an iodine value of >=65 and (C) 0.01-0.5wt.% of a metallic soap. The composition is preferably further incorporated with (D) 0.01-0.5wt.% of an inorganic filler and (E) 0.01-0.3wt.% of a higher saturated fatty acid amide having a melting point of >=100 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a transparent and lubricious ethylene-vinyl acetate copolymer film.
More specifically, the present invention is transparent, slippery, and has good blocking resistance, and is used for back-in-box, V-pro film used for mold making of casting, agricultural film, and laminating. The present invention relates to a film suitable as a film or the like.

[0002]

2. Description of the Related Art Ethylene-vinyl acetate copolymer films having a relatively high vinyl acetate content are widely used for various purposes because of their high transparency, but they have the problem of low lubricity. . In order to solve this problem, cornstarch powder or the like has been sprayed on the film surface before winding the film. However, this method has the drawbacks that a powder spraying process is required and the film appearance is deteriorated. There is also a method of imparting lubricity by adding a lubricant such as higher fatty acid amide, but in this method, there is a problem that the film surface is whitened due to the bleed-out of the additive. Further, in order to prevent the bleed-out of the additive, if the amount of the lubricant such as higher fatty acid amide added is reduced and a large amount of the inorganic filler is added, the transparency of the film is deteriorated.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks, and it is a vinyl acetate-containing material which is imparted with lubricity without lowering transparency and has good blocking resistance. An object is to provide an ethylene-vinyl acetate copolymer film having a relatively high amount.

[0004]

Means for Solving the Problems A film obtained by adding a higher fatty acid amide for imparting lubricity to an ethylene-vinyl acetate copolymer film having a relatively high vinyl acetate content has a bleeding agent of the additive as described above. The film surface becomes white due to out. However, the present inventor found that addition of metal soap together with higher fatty acid amide did not cause bleed out of the additive, and further earnestly studied to complete the present invention.

That is, the present invention has a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10.
The higher fatty acid amide having an iodine value of 65 or more is added in an amount of 0.01 to 0.
5% by weight and 0.01 to 0.5% by weight of metal soap are added to a transparent and slippery ethylene-vinyl acetate copolymer film. Further, the present invention relates to an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10 g / 10 minutes, and 0.01 or more of a higher fatty acid amide having an iodine value of 65 or more. ~ 0.5% by weight, 0.01% metallic soap
~ 0.5 wt% and 0.01-0.5% inorganic filler
It relates to a transparent and slippery ethylene-vinyl acetate copolymer film, which is characterized in that it is added by weight%. Furthermore, the present invention relates to an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10 g / 10 min, and a higher fatty acid amide having an iodine value of 65 or more of 0.01 to. 0.5% by weight, 0.01 to 0.5% by weight of metallic soap, 0.01 to 0.5% of inorganic filler
It relates to a transparent and slippery ethylene-vinyl acetate copolymer film, which is characterized by adding 0.01 to 0.3% by weight of a higher saturated fatty acid amide having 0.5% by weight and a melting point of 100 ° C. or higher.

The ethylene-vinyl acetate copolymer used in the present invention is intended to have a relatively high vinyl acetate content, that is, a vinyl acetate content of 10 to 25%, in view of applications and the like. It should be noted that there is no use for those having a vinyl acetate content exceeding 26%. Further, the melt index (MI) of this ethylene-vinyl acetate copolymer is in the range of 0.1 to 10 g / 10 minutes, but when the MI is less than 0.1 g / 10 minutes, the extruder is used during film formation. Is not desirable because it will not be overloaded and the productivity will not increase, while MI is 10g / 10
If the amount exceeds the limit, melt tension becomes insufficient during film forming, and film processability deteriorates, which is not desirable. Further, as the ethylene-vinyl acetate copolymer, the melting point (MP) and the vinyl acetate content (VA) have the following formula: MP = 114-1.4.
4VA (However, MP unit is ° C, VA unit is wt%)
What is represented by the relational expression of is suitable. The reason for this is that if the above-mentioned relational expressions are compared at the same VA%,
It has a melting point of 2-5 than that of general ethylene-vinyl acetate copolymer.
This is because the temperature is high and the heat resistance is improved. Also, among other things,
Those having a molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of less than 4 are particularly suitable, but those having the above molecular weight distribution (Mw / Mn) are particularly tough. It gives a film and has less odor.
Therefore, the ethylene-vinyl acetate copolymer used in the present invention has a melting point (MP) and a vinyl acetate content (V
A) is the following formula: MP = 114-1.44VA (however, M
It is particularly preferable that the unit of P is represented by a relational expression of ° C, the unit of VA is% by weight, and the molecular weight distribution (Mw / Mn) is less than 4.

The higher fatty acid amide used in the present invention has an iodine value of 65 or more. Iodine value is 6
If higher fatty acid amides less than 5 are used, the lubricity of the film will be insufficient. Specific examples of the higher fatty acid amide having an iodine value of 65 or more include oleic acid amide and erucic acid amide. The amount of the amide added is 0.01 to 0.5% by weight. This is because if the added amount is less than 0.01% by weight, the slipperiness of the film is insufficient,
Even if it exceeds 0.5% by weight, the effect of improving the lubricity reaches saturation,
Not only is there no further improvement, but the possibility of bleed-out is increased, which is undesirable.

The metal soap used in the present invention is not particularly limited, and ordinary ones can be used, for example, fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, 12-hydroxystearic acid and zinc. , Metal salts with metals such as aluminum, calcium, magnesium, lithium, barium, cadmium and lead. Of these, zinc stearate and calcium stearate are common and are preferably used. The amount of metal soap added is 0.01 to 0.5% by weight. This is because if it is less than 0.01% by weight, the bleed-out preventing effect of the amide is insufficient, and if it exceeds 0.5% by weight, the printability of the film is deteriorated, which is not desirable.

The inorganic filler in the present invention is an ordinary anti-blocking agent for films, having a particle size of 1 to 10 μm.
As long as it is a fine powder, it may be natural or synthetic. Specific examples include silica, talc, feldspar, diatomaceous earth, zeolite, calcium carbonate, clay, barium sulfate and the like. When an inorganic filler is used, the amount added is 0.01 to 0.5% by weight. If the amount added is less than 0.01% by weight, the antiblocking effect of the film becomes insufficient, and if it exceeds 0.5% by weight, the transparency of the film deteriorates, which is not desirable.

The higher saturated fatty acid amide which can be used in the present invention has a melting point of 100 ° C. or higher, and specifically, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearin. Examples thereof include acid amide and ethylene bisbehenic acid amide. Although the amount of the higher saturated fatty acid amide added is 0.01 to 0.3% by weight,
If it is less than 01% by weight, the effect of blocking prevention of the film is insufficient, and if it exceeds 0.3% by weight, the printability of the film is deteriorated, which is not desirable.

In addition to the above-mentioned essential components, the film of the present invention contains antioxidants such as phenolic antioxidants, phosphorus antioxidants, and sulfur in order to obtain thermal stability of the film during processing and after molding. It is also possible to add a system antioxidant and the like: Examples of phenol system antioxidants: tetrakis [methylene-
3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, n-octadecyl-3-
(3,5-Ditert-butyl-4-hydroxyphenyl) propionate, dibutylhydroxytoluene, butyric acid 3,3-bis (3-tert-butyl-4-hydroxyphenyl) ethylene ester, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)
Isocyanuric acid, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4
8,10-tetraoxaspiro [5.5] undecane,
2-tert-butyl-6- (3-tert-butyl-5-methyl-
2-hydroxybenzyl) -4-methylphenyl acrylate and the like. Examples of phosphorus antioxidants: distearyl pentaerythritol diphosphite, tetrakis (2,4-ditertiary butylphenyl) -4,4'-biphenylene diphosphite, bis (2,4-ditertiary butyl) Pentaerythritol diphosphite, tris (2,4-ditert-butylphenyl) phosphite, bis (2,6-ditert-butyl-4)
-Methylphenyl) pentaerythritol diphosphite, trisnonylphenylphosphite, 2,2-methylenebis (2,4-di-tert-butylphenyl) octylphosphite, bis (2,4,6-tritert-butylphenyl) ) Pentaerythritol diphosphite and the like. Examples of sulfur antioxidants: dilauryl 3,3′-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3′-thiodipropionate, pentaerythrityl tetrakis (3-lauryl) Thiopropionate), ditridecyl 3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. The above antioxidants may be used alone or in combination of two or more. In the film of the present invention, resin additives other than the above-mentioned antioxidants, for example, colorants, pigments, carbon black, processability improvers, eye-gaze inhibitors, antifogging agents, antistatic agents, ultraviolet absorbers, light stabilizers, etc. May be added within the range not impairing the purpose of the present invention, depending on the purpose and use.

In order to produce the film of the present invention, it is necessary to first mix the above-mentioned compounding components, which can be carried out by a known method, for example, melt mixing of various compounding components using a mixer or an extruder. Can be done by doing. The film production can also be carried out by a known method, for example, an inflation method using an annular die, a T die method using a flat die, or the like.

The film of the present invention can of course be used alone, but it is also used as a coextrusion film with other polyolefins such as high-pressure low density polyethylene, linear low density polyethylene or high density polyethylene, polypropylene and the like. You can also

[0014]

As described above, the present invention provides an ethylene-vinyl acetate copolymer film having a relatively high vinyl acetate content,
By adding a metal soap together with a higher fatty acid amide having an iodine value of 65 or more, which is effective as a lubricant, bleed out of the lubricant is prevented, transparency is not adversely affected, and good lubricity and blocking resistance are obtained. That is what I found. The reason why the lubricant does not bleed out is not yet known, but an ionic bond occurs between the polyvalent metal of the metal soap and the unsaturated bond of the higher fatty acid amide having an iodine value of 65 or more, and the amide is unnecessarily formed on the film surface. It is thought that it does not bleed. Further, if desired, by further adding an inorganic filler and a higher saturated fatty acid amide having a melting point of 100 ° C. or higher,
The blocking resistance can be further enhanced.

[0015]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples. Example 1 Vinyl acetate content 15%, MI 2.3 g / 10 min,
An ethylene-vinyl acetate copolymer (trade name NUC-3758, manufactured by Nippon Unicar Co., Ltd.) produced by radical polymerization by a high-pressure method having a melting point of 93 ° C. and a molecular weight distribution of 3.3 was added to Elka as a higher fatty acid amide having an iodine value of 65 or more. Add 0.4% by weight of acid amide, 0.1% by weight of zinc stearate as metal soap, and further add tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) as an antioxidant. Propionate] Methane was added in an amount of 0.03 part by weight based on 100 parts by weight of the resin composition. The resin composition thus obtained was melt-kneaded with a Banbury mixer, then granulated through an extruder, and a film with a thickness of 40 μm was prepared by a 50 mm inflation tubular film extruder manufactured by Placo (film forming condition: resin Temperature 150 ℃, die diameter 150mm, blow ratio 2.0). The obtained film was evaluated for optical properties, lubricity, bleed-out property, and blocking resistance.
The results are summarized in Table 1. Examples 2 to 5 and Comparative Examples 1 to 5 The same experiment as in Example 1 was performed except that the additives in Example 1 were changed as shown in Table 1. Also, an antioxidant was added in the same manner as in Example 1. The results are also summarized in Table 1.

[Table 1] (Footnote of Table 1) * 1: All units of the compounding amount of the additive are wt% and are the following substances. Higher fatty acid amide = erucic acid amide, metal soap = zinc stearate, inorganic filler = talc, higher saturated fatty acid amide = ethylenebisstearic acid amide * 2: The evaluation methods and evaluation criteria for each physical property are as follows. Haze (unit,%): measured according to ASTM D 1003 ◎ = value is 3 or less and excellent ○ = value is 7 or less and practical x = value is 8 or more Yes, non-practical Gloss 45 °: measured according to ASTM D 523 ◎ = numerical value of 60 or more, excellent ○ = numerical value of 50 or more, practicable × = numerical value Not more than 49, which is not practical Friction coefficient Outside: Measured according to ASTM D 1894 ◎ = Number is 0.3 or less, highly slippery ○ = Number is 0.5 or less, smooth Possessive property × = Numerical value of 0.6 or more, with or without slipperiness Bleed-out property: Observe film appearance after 7 days at room temperature ○ = No bleed-out × = Bleed-out With blocking resistance (unit, / 100cm ^2): AST
Measured in accordance with M D 3354 ⊚ = value is 50 or less and is excellent ∘ = value is 100 or less and is practical x = Value is greater than 100 and is not practical

[0016]

As described in detail above, the present invention is
It is possible to impart lubricity to an ethylene-vinyl acetate copolymer film having a relatively high vinyl acetate content without lowering its transparency, and also to impart good blocking resistance. This blocking resistance can be further enhanced by adding an inorganic filler or a specific higher saturated fatty acid amide, if necessary. Thus, the ethylene-vinyl acetate copolymer film of the present invention has excellent transparency, lubricity and blocking resistance, and further expands the applications of the conventional ethylene-vinyl acetate copolymer film. Is something
It is particularly suitable as a back-in-box, a V-pro film, an agricultural film, a laminating film and the like.

Claims (4)

[Claims] 1. An ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10 g / 10 minutes, and 0.01 to 5 of a higher fatty acid amide having an iodine value of 65 or more. A transparent and slippery ethylene-vinyl acetate copolymer film, characterized in that 0.5% by weight and 0.01 to 0.5% by weight of metal soap are added. 2. An ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10 g / 10 minutes, and 0.01 to 5 of a higher fatty acid amide having an iodine value of 65 or more. 0.5% by weight, 0.01-0.5% by weight of metallic soap and 0.0% of inorganic filler.
A transparent and slippery ethylene-vinyl acetate copolymer film, characterized in that 1 to 0.5% by weight is added. 3. An ethylene-vinyl acetate copolymer having a vinyl acetate content of 10 to 25% and a melt index of 0.1 to 10 g / 10 minutes, and 0.01 to 500 of a higher fatty acid amide having an iodine value of 65 or more. 0.5% by weight, 0.01 to 0.5% by weight of metallic soap, 0.01 to 0.5% of inorganic filler
A transparent and slippery ethylene-vinyl acetate copolymer film, characterized by containing 0.01 to 0.3% by weight of a higher saturated fatty acid amide having 0.5% by weight and a melting point of 100 ° C. or higher. 4. An ethylene-vinyl acetate copolymer having a melting point (MP) and a vinyl acetate content (VA) represented by the following formula: MP =
114-1.44VA (however, the unit of MP is ° C, the unit of VA is weight%), and the molecular weight distribution (Mw /
Mn) is less than 4, The ethylene-vinyl acetate copolymer film according to any one of claims 1 to 3.