JPH059345A - Production of polyolefinic resin molding - Google Patents

Abstract

PURPOSE:To obtain the title molding having functions such as deodoring, bacteriostasis or freshness preservation by melting and molding a composition made by adding powdered glyoxal to a polyolefinic resin. CONSTITUTION:(A) a polyolefinic resin such as PE or PP is blended with (B) 0.2-15wt.% (preferably 0.5-5wt.%) of powdered glyoxal composed of 2,3- dihydroxy-1,4-dioxane by melting and molding at 145-220 deg.C to give the objective molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a process for producing a polyolefin resin molded product having functions such as deodorant property, bacteriostatic property, and freshness-retaining property.

[0002]

BACKGROUND OF THE INVENTION Polyolefin resins such as polyethylene and polypropylene have good molding processability and are excellent in the appearance, moisture resistance and mechanical properties of molded products, so they are widely used in various applications such as films, sheets, containers and fibers. Has been done.

[0003]

However, due to its non-polar structure, polyolefin resins are inferior in multifunctional properties such as deodorant properties, bacteriostatic properties, and freshness-retaining properties, and are therefore subject to the use of garbage bags and oxidation. There are some unsatisfactory points as a packaging material for foods that are easily deteriorated.

Therefore, if such a function can be imparted to the resin by using some means, its utility value will be further expanded. As a countermeasure for this, a polyolefin or the like is blended with zeolite or the like, but the fact is that the transparency and meltability of the molded product are impaired and there are merits and demerits, so that satisfactory physical properties cannot always be obtained.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a composition obtained by blending a powdery glyoxal with a polyolefin resin is
The present invention has been completed by finding that the object can be achieved in the case of melt molding.

The present invention will be described in detail below. As the polyolefin resin of the present invention, linear low density / low density
Examples thereof include high density polyethylene, ionomer, ethylene-propylene copolymer, crystalline polypropylene, polybutene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and the like.

Particularly, linear low density polyethylene, low density polyethylene, high density polyethylene and isotactic polypropylene are practically important.

The resin has a melt flow rate of 0.05 to 100 g / 10 minutes, preferably 0.1, measured at 210 ° C. and a load of 2160 g according to JIS K-6760.
The thing of -20g / 10min is used.

In the present invention, it is essential to use powdery glyoxal. Since glyoxal is usually marketed in the form of an aqueous solution, it must be dehydrated, lumped, and ground. Not only such a pulverized product, but also 2,3-dihydroxy-1,4-dioxane (see Japanese Patent Application Laid-Open No. 53-111079), which is a reaction product of glyoxal and ethylene glycol, is useful because the same effect as glyoxal can be obtained. is there.

The content of the glyoxal should be 0.2 to 15% by weight, preferably 0.5 to 5% by weight, based on the polyolefin resin. When the content of glyoxal is 0.2% by weight or less, the effect of the present invention is difficult to obtain, and the functions of deodorant property, bacteriostatic property and freshness-retaining ability cannot be exhibited, while when the content of glyoxal is 15% by weight or more, molding is performed. The transparency of the product decreases.

Thus, such a composition is melt-molded into a molded product. By melt-kneading, various molded products such as pellets, films, sheets, containers, fibers, rods, tubes, etc. are molded. In many cases, these crushed products (such as when the collected product is reused) and pellets are used again for melt molding. As the melt molding method, extrusion molding (T-die extrusion, inflation extrusion, blow molding, melt spinning, profile extrusion, etc.),
The injection molding method is mainly adopted. Melt molding temperature is 14
Often selected from the range of 5 to 220 ° C. In addition to the injection molding method, a two-color molding method, an ink jet blow molding method, and the like can be included to obtain a molded product with good dimensional accuracy.

At the time of molding, a suitable amount of a plasticizer, a stabilizer, a surfactant, a crosslinkable substance, a filler, a coloring agent, a fiber as a reinforcing material (glass fiber, carbon fiber, etc.) and the like can be added. Further, other thermoplastic resins may be blended in appropriate amounts, and as such other thermoplastic resins, polyolefins which do not overlap with the polyolefins used, or modified polyolefins and polyamides obtained by graft-modifying these with unsaturated carboxylic acids or derivatives thereof are used. ,PVC,
Polyvinylidene chloride, polyester, polystyrene, polyacrylonitrile, polyurethane, polyacetal,
Examples include polycarbonate and melt-moldable polyvinyl alcohol-based resins.

The molded article of the present invention may be put to practical use as a laminated structure having at least one layer of the composition, in addition to the production of the molded article having only the composition as a single layer. In manufacturing a laminated structure, another substrate is laminated on one side or both sides of the layer of the composition of the present invention, and as a laminating method, for example, a composition film or a sheet is melted with a thermoplastic resin. Extrusion method, conversely a method of melt-extruding the composition of the present invention into a substrate such as a thermoplastic resin, a method of co-extruding the composition of the present invention and another thermoplastic resin, further the composition of the present invention The method of laminating the film, sheet and the film of the other substrate with the known adhesive agent such as organic titanium compound, isocyanate compound, polyester compound and the like can be mentioned.

In the case of coextrusion, the other resin is linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ionomer, ethylene-propylene copolymer, ethylene. -Acrylic ester copolymer, polypropylene, propylene-α-olefin (having 4 to 20 carbon atoms)
Α-olefin) copolymer, polybutene, homopolymers or copolymers of olefins such as polypentene, or a broad definition of homo- or copolymers of these olefins graft-modified with unsaturated carboxylic acids or their esters. Polyolefin resin, polyester, polyamide,
Copolymerized polyamide, polyvinyl chloride, polyvinylidene chloride, acrylic resin, styrene resin, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene, chlorinated polypropylene, etc. may be mentioned. Saponified ethylene-vinyl acetate copolymers can also be coextruded.

The film, sheet, container and the like obtained by the present invention are useful as various packaging materials such as foods, pharmaceuticals, industrial chemicals and agricultural chemicals, garbage bags, gloves and the like.

[0016]

In the present invention, a molded product composed of polyolefin and glyoxal has a deodorizing property and a static property while maintaining the molded physical properties and mechanical properties such as the excellent stretchability and flexibility originally possessed by the polyolefin resin. It is possible to improve fungal properties and freshness retention.

[0017]

EXAMPLES Next, the composition of the present invention will be described more specifically with reference to examples. Hereinafter, “part” is expressed on a weight basis unless otherwise specified. Example 1 A composition pellet of 100 parts of low-density polyethylene having a density of 0.92 and 2 parts of powdery glyoxal was mixed using a Henschel mixer, and the mixture was supplied to an extruder equipped with a T-die and melt-kneaded, A film having a thickness of 30 μm was manufactured by extruding from a T-die. The conditions for extrusion molding are as follows.

Extruder: 40 mm diameter extruder Screw: Full flight type L / D = 28,
CR = 3 Extrusion temperature: C1 / C2 / C3 / C4 / H / D1 / D2 =
170/200/220/220/220/210/2
10 Screw rotation speed: 30 rpm The obtained film was made into a bag, household garbage was stored, and the film was left for 7 days. After opening the bag, no odor was found.

Example 2 100 parts of low-density polyethylene and 2,3-dihydroxy-
A composition with 3 parts of 1,4-dioxane was pelletized as in Example 1 and mixed using a Henschel mixer,
The film was supplied to an extruder equipped with a T-die, melt-kneaded, and extruded from the T-die to produce a film having a thickness of 30 μm. The obtained film was made into a bag, and household garbage was stored and left for 10 days. After opening the bag, no odor was found.

[0020]

The molded product obtained from the composition of the polyolefin resin and the powdery glyoxal of the present invention has deodorant property, bacteriostatic property and freshness retention property while maintaining the excellent physical properties of the polyolefin resin. Is given.

Claims (3)

[Claims] 1. A method for producing a polyolefin resin molded product, which comprises melt-molding a composition obtained by blending a powdery glyoxal with a polyolefin resin. 2. The method for producing a molded article according to claim 1, wherein the polyolefin resin is low density polyethylene or high density polyethylene. 3. The method for producing a molded article according to claim 1, wherein the powdery glyoxal is 2,3-dihydroxy-1,4-dioxane.