JPH11199741A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which is highly practicable and can give, especially, food packaging materials for retort sterilization excellent in transparency, uniformity, retorting resistance, etc., by melt-mixing a polyamide resin with an alcoholic compound and adding an ethylene/vinyl acetate copolymer saponificate to the mixture. SOLUTION: The polyamide resin used desirably is an amorphous nylon or an aliphatic nylon. The alcoholic compoun1d used is desirably a polyhydric alcohol. The weight ratio polyamide resin/alcoholic compound is desirably 99/1 to 60/40. Desirably that the melt mixing is performed at 100-280 deg.C. The weight ratio melt mixture/ethylene-vinyl acetate copolymer saponificate (EVOH) is desirably 4/96 to 40/60. The mixing of the melt mixture with EVOH is desirably carried by melt mixing, and the melting temperature in this mixing is desirably 150-250 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyamide resin and a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as EV).
More specifically, the present invention relates to a resin composition having excellent transparency and retort resistance.

[0002]

2. Description of the Related Art Heretofore, EVOH has been widely used as various packaging films for foods and the like by utilizing its gas barrier property and transparency. However, on the other hand, since EVOH is hydrophilic, it has disadvantages such as high water permeability, lack of hot water resistance, rigidity, and lack of impact resistance.
Many attempts have been made to blend a polyamide resin with EVOH by means of improving the moldability of VOH (JP-B-44-24277, JP-B-48-148).
No. 22833, JP-A-50-121347,
JP-B-60-24813, JP-B-60-2481
No. 4, JP-A-64-9238, JP-A-4-7
No. 6039, Japanese Patent Publication No. 5-1819).

[0003]

SUMMARY OF THE INVENTION However, EVO
In melt-mixing H and polyamide-based resin, if only a certain kind of polyamide-based resin is used by simply melt-mixing, the EV obtained is poor due to poor compatibility of both.
The transparency of the resin composition of OH and polyamide resin is reduced, or the moldability when molding into a film or the like is reduced, and furthermore, the physical properties such as retort resistance when used for food packaging. Therefore, there is a demand for a good EVOH- and polyamide-based resin composition free of these concerns.

[0004]

The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems. As a result, after melt-mixing a polyamide resin and an alcohol compound, an EV was obtained.
The present inventors have found that a resin composition to which OH is added can solve the above problems, and have completed the present invention.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. Examples of the polyamide resin used in the present invention include polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), and polyundecaneamide (nylon-11). ), Polylauryl lactam (nylon-1
2), polyethylenediamine adipamide (nylon-
2, 6), polytetramethylene adipamide (nylon-
4, 6), polyhexamethylene adipamide (nylon-
6, 6), polyhexamethylene sebacamide (nylon-
6, 10), polyhexamethylene dodecamide (nylon-6, 12), polyoctamethylene adipamide (nylon-8, 6), polydecamethylene adipamide (nylon-10, 8), caprolactam / lauryl lactam Copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 6, 6), lauryl lactam / Hexamethylenediammonium adipate copolymer (nylon-12 / 6,6), ethylenediamine adipamide /
Hexamethylene diammonium adipate copolymer (nylon-2, 6/6, 6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6, 6 /
6, 10), ethylene ammonium adipate / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6 / 6,
6/6, 10), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexamethylene isophthalamide / terephthalamide copolymer or a polyamide resin thereof is modified with an aromatic amine such as methylene benzylamine or meta-xylene diamine. And metaxylylenediammonium adipate. One or more of these are used, and among them, hexamethylene isophthalamide /
Amorphous nylon such as terephthalamide copolymer and aliphatic nylon such as caprolactam / hexamethylene diammonium adipate copolymer (nylon-6 / 6, 6) and polylauryl lactam (nylon-12) are preferably used. .

[0006] Alcohol compounds that are melt-mixed with the polyamide resin include alcoholic OH.
It is not particularly limited as long as it has a group, and specifically, ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, sec-butyl alcohol, te
rt-butyl alcohol, n-amyl alcohol, isoamyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, caprylic alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl Alcohol, heptadecyl alcohol, stearyl alcohol, nanodecyl alcohol, eicosyl alcohol, seryl alcohol, melisyl alcohol, allyl alcohol, crotyl alcohol, propargyl alcohol, cyclopentane alcohol, cyclohexane alcohol, benzyl alcohol, cinnamyl alcohol, furfuryl Monohydric alcohols and glycos such as alcohols and fatty acid monoglycerides , Diglycol, triglycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4- Butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, neopentyl glycol, 1,2,6-hexanetriol, 1,3,5-hexanetriol, trimethylpropane, glycerol Polyhydric alcohols such as diglycerin, sorbitol, pentaerythritol stearate, pentaerythritol adipate, dipentaerythritol pyrrolidonecarboxylate, dipentaerythritol glutamate, and maleic anhydride-modified wood rosin pentaerythritol; Can be exemplified an alcohol-based compounds such as polyvinyl alcohol-based resin, preferably a di-glycol, triethylene glycol, 1,
3-butanediol, 2,3-butanediol, 1,4
-Butanediol, 1,2,6-hexanetriol,
Polyhydric alcohols such as 1,3,5-hexanetriol, glycerol and sorbitol are used.

Further, the EVOH to be blended with the above-mentioned molten mixture of the polyamide resin and the alcoholic compound is not particularly limited, but it has an ethylene content of 60 mol% or less (more preferably 20 to 55 mol%) and a vinyl acetate component. When the ethylene content exceeds 60 mol%, the gas barrier property is reduced, and the saponification degree is less than 90 mol%. In this case, the gas barrier property is lowered and the thermal stability is deteriorated, which is not preferable.

Further, the EVOH may further contain a small amount of an α-olefin such as propylene, isobutene, α-octene, α-dodecene, α-octadecene, an unsaturated carboxylic acid or a salt thereof, a partial alkyl ester, a complete alkyl ester, a nitrile. Comonomers such as amides / anhydrides, unsaturated sulfonic acids or salts thereof may be included. Also,
The melt index (MI) of EVOH is 0.5 to 5
0 g / 10 min (210 ° C., 2160 g load) is preferable, and 1 to 35 g / 10 min (same as above) is preferable. If the MI is less than 0.5 g / 10 minutes (same as above), the viscosity becomes so high that melt extrusion cannot be carried out.
When the time exceeds / 10 minutes (same as above), the film-forming property is undesirably reduced.

The most characteristic feature of the present invention is that when the polyamide resin is mixed with the EVOH, the alcohol compound is melt-mixed in advance with the polyamide resin. Such melt mixing will be described. The melt mixing ratio of the polyamide resin and the alcohol compound is not particularly limited.
The weight ratio of the alcohol compound is preferably from 99/1 to 60/40, more preferably from 98/2 to 55/45. If the weight ratio exceeds 99/1, the compatibility with EVOH is insufficiently improved. , Causing poor film appearance,
When the ratio is less than 0/40, it is difficult to stably form the resin composition into strands, which is not preferable. Such melt mixing is preferably performed at 100 to 280 ° C.
If the temperature is less than 100 ° C., the meltability and extrusion moldability of the polyamide resin are reduced, and conversely,
If the temperature exceeds 0 ° C., the alcohol compound may vaporize, which is not preferable. The method of melt mixing is not particularly limited, but usually an extruder such as a single screw extruder or a twin screw extruder can be used.

By the above method, a molten mixture of a polyamide resin and an alcohol compound can be obtained, and then the resin composition of the present invention can be obtained by blending the molten mixture with EVOH. The molten mixture and E
The blending weight ratio of VOH is not particularly limited, but usually, the weight ratio of the molten mixture / EVOH is preferably 4/96 to 40/60, and if the weight ratio is less than 4/96, the expression of retort resistance is insufficient. On the other hand, if the ratio exceeds 40/60, the gas barrier property is undesirably reduced. Further, it is preferable that the mixture of the molten mixture and EVOH is also a molten mixture, and the melting temperature at this time is preferably 150 to 250 ° C, more preferably 155 to 245 ° C, and the temperature is 150 ° C.
When the temperature is less than 250 ° C., the melt mixing property decreases. On the contrary, when the temperature exceeds 250 ° C., the EVOH deteriorates and the reaction between the EVOH and the polyamide resin is unfavorable, and the method of melt mixing is not particularly limited. Instead, an extruder such as a single-screw extruder or a twin-screw extruder can be used as in the above.

Further, in the present invention, an antioxidant, a lubricant, an EVOH or a polyamide resin, and further a resin composition of the present invention obtained from these compounds and an alcohol compound.
UV absorbers, flame retardants, coloring agents, anti-blocking agents,
It is also possible to add an antistatic agent, a filler, etc., and may contain a metal (alkali metal, alkaline earth metal, transition metal, etc.) salt, and further contains boron, silica, etc. Is also good. Thus, the obtained resin composition of the present invention is formed into a film or a sheet, and further uniaxially or biaxially stretched, not only as a single layer, but as a laminate having at least one such film or sheet. Use is also useful, and such a laminate will be further described.

In producing the laminate, (dry)
Lamination may be carried out, or a laminate may be produced by a multilayer extruder. When a laminate is produced by lamination, another substrate is laminated on one or both sides of the molded article (film, sheet, etc.) of the present invention. And a method of laminating the film or sheet of the base material with a known adhesive such as an organic titanium compound, an isocyanate compound, or a polyester compound.

Examples of such other base films include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, EVA, ionomer, ethylene-propylene copolymer, ethylene-acrylate copolymer. , Polypropylene, propylene-
α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, homo- or copolymer of olefin such as polybutene, polypentene, or homo- or copolymer of these olefins with unsaturated carboxylic acid or ester thereof Broadly defined polyolefin resin such as graft-modified resin, polystyrene resin, polyester, polyamide, copolymerized polyamide, polyvinyl chloride, polyvinylidene chloride, acrylic resin, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene , Chlorinated polypropylene, EVOH and the like,
Further, paper, metal foil, uniaxially or biaxially stretched plastic film or sheet, woven fabric, nonwoven fabric, metal cotton strip, wood surface, and the like can also be used. Regarding the layer structure of the laminate, the layer of the molded product (film) of the present invention is I (I ₁ , I ₂ ,...), And another substrate such as a thermoplastic resin layer is II (II ₁ , II _2). , ...
・), If it is a film or sheet, I / II
Not two-layer structure of only, II / I / II, I / II / I, I 1 / I 2
/ II, it can be any combination, such as _{I / II 1 / II 2,} II 2 / II 1 / I / II 1 / II 2.

The resin composition of the present invention is excellent in transparency, furthermore excellent in moldability when formed into a film or the like, and such a film is also excellent in retort resistance and the like, and is excellent in foods, pharmaceuticals, agricultural chemicals, industrial It is very useful for applications such as films, sheets, tubes, bags, containers and the like for packaging chemicals, and is particularly useful for sterilizing retorts for food packaging.

[0015]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” mean on a weight basis unless otherwise specified. Example 1 Amorphous nylon (“Novamid X21”, manufactured by Mitsubishi Chemical Corporation)
85 parts and 15 parts of sorbitol were fed to a twin screw extruder,
Melt mixing was performed at 250 ° C. (barrel temperature) to obtain a molten mixture. Next, 10 parts of the obtained molten mixture and EVO
90 parts of H [ethylene content 30 mol%, saponification degree 99.8 mol%] is supplied to a twin-screw extruder and melt-mixed at 235 ° C. (barrel temperature) to obtain a resin composition of the present invention. Obtained. The following evaluation was performed using the obtained resin composition. (Transparency) The resin composition is supplied to a single screw extruder equipped with a T die, and a film having a thickness of 30 μm is formed.
The haze value of the film obtained after 100 hours was measured and evaluated as follows. ○ --- Haze value is less than 10 × --- Haze value is 10 or more The film forming conditions by the single screw extruder were as follows. Screw inner diameter 40mm L / D 28 Screw compression ratio 3.8 T die Coat hanger type Die width 450mm Extrusion temperature C1: 210 ° C, H: 230 ° C C2: 220 ° C, D: 220 ° C C3: 230 ° C, C4: 230 ° C

(Moldability) In the above single-layer melt molding,
The state of generation of gel on the film surface when molding was performed for a long time of 100 hours was visually observed and evaluated as follows. ○ −−− Gel generation is less than 10 / m ² × −−− Gel generation is 10 / m ² or more

(Retort Resistance) The obtained film (unstretched film) was retorted at 120 ° C. for 30 minutes, allowed to stand at room temperature for 30 minutes, and the appearance of the film was visually observed and evaluated as follows. − −−− Transparent and no discoloration was observed. × --- Discoloration or delamination due to haze or whitening was observed.

Example 2 In Example 1, an amorphous nylon (manufactured by Mitsubishi Chemical Corporation,
"Novamid X21") A resin composition was prepared in the same manner except that a melt mixture was obtained using 95 parts and 5 parts of 2,3-butanediol, and the same evaluation was performed.

Example 3 In Example 1, an aliphatic nylon (manufactured by Mitsubishi Chemical Corporation,
"Novamid 2030") A resin composition was prepared in the same manner except that a melt mixture was obtained using 70 parts and 2,3-butanediol 30 parts, and the same evaluation was performed.

Example 4 In Example 1, an amorphous nylon (manufactured by Mitsubishi Chemical Corporation,
(Novamid X21)) A melt mixture was obtained using 75 parts and 25 parts of sorbitol, and the amount of EVOH was adjusted to 80 parts using EVOH having an ethylene content of 45 mol% and a saponification degree of 99.8 mol%. A resin composition was produced in the same manner except that the amount of the molten mixture was changed to 20 parts, and the same evaluation was conducted.

Example 5 In Example 3, an aliphatic nylon (manufactured by Mitsubishi Chemical Corporation,
[Novamid 2030]) A resin composition was prepared using 80 parts and 20 parts of glycerol, and a resin composition was prepared in the same manner except that EVOH was changed to 70 parts and the melt mixture was changed to 30 parts. went.

Example 6 In Example 3, an aliphatic nylon (manufactured by Mitsubishi Chemical Corporation,
"Novamid 2030") A resin composition was prepared in the same manner except that a melt mixture was obtained using 90 parts and 10 parts of sorbitol, and the same evaluation was performed.

Example 7 In Example 1, the alcohol compound was changed to 1,3,5-
A resin composition was prepared in the same manner except that hexanetriol was used, and the same evaluation was performed.

Comparative Example 1 Example 1 was repeated, except that sorbitol was not used and amorphous nylon (Novamid X21, manufactured by Mitsubishi Chemical Corporation) was used.
Parts and 90 parts of EVOH were supplied to a twin-screw extruder and melt-mixed to produce a resin composition, which was similarly evaluated.

Comparative Example 2 In Example 1, an amorphous nylon (manufactured by Mitsubishi Chemical Corporation,
"Novamid X21") 99.7 parts, sorbitol 0.3
Parts and 90 parts of EVOH were batch-blended and supplied to a twin-screw extruder, and melt-mixed at 235 ° C. (barrel temperature) to produce a resin composition, which was similarly evaluated.

Comparative Example 3 A resin composition was prepared in the same manner as in Example 1 except that sorbitol was not used, and was similarly evaluated. Table 1 shows the evaluation results of the examples and the comparative examples.

[0027]

[Table 1]

[0028]

The resin composition of the present invention is excellent in transparency, uniformity, retort resistance and the like, so that it can be used as a film, sheet, tube, or the like for packaging foods, pharmaceuticals, agricultural chemicals, and industrial chemicals.
It is very useful for applications such as bags and containers, and is particularly useful for disinfecting retorts for food packaging.

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[Procedure amendment]

[Submission date] December 18, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

Comparative Example 2 In Example 1, 9.7 parts of amorphous nylon ("Novamid X21", manufactured by Mitsubishi Chemical Corporation), 0.3 parts of sorbitol and 90 parts of EVOH were batch-blended and supplied to a twin-screw extruder. Then, melt-mixing was performed at 235 ° C. (barrel temperature) to produce a resin composition, which was similarly evaluated. Table 1 shows the evaluation results of the examples and the comparative examples.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Deleted

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

[0027]

[Table 1]

Claims (6)

[Claims] 1. A resin composition comprising a polyamide resin and an alcohol compound melt-mixed, and then a saponified ethylene-vinyl acetate copolymer is added. 2. The resin composition according to claim 1, wherein the polyamide resin is amorphous nylon and / or aliphatic nylon. 3. The resin composition according to claim 1, wherein the alcohol compound is a polyhydric alcohol. 4. The resin composition according to claim 1, wherein a melting temperature of the polyamide-based resin and the alcohol-based compound at the time of melt-mixing is 100 to 280 ° C. 5. The resin composition according to claim 1, wherein the weight ratio by weight of the polyamide resin and the alcohol compound is from 99/1 to 60/40. 6. The compounding weight ratio of a molten mixture of a polyamide resin and an alcohol compound to a saponified ethylene-vinyl acetate copolymer is from 4/96 to 40/60. The resin composition according to any one of the above.