JPS59157131A - Container - Google Patents

Abstract

PURPOSE:A container that is made of a resin composition consisting of a polyolefin resin and talc at a specific ratio, thus being suitable for use in making cups in picnic, because of its touch like high-class white paper, high safety from food-sanitary joint of view, readiness to be incinerated, low costs, and light weight. CONSTITUTION:30-80, preferably 40-70wt% of a polyolefin resin, preferably a resin composition composed of 40-90wt% of a polypropylene resin and 60- 10wt% of a polyethylene resin, and 70-20, preferably 60-30wt% of talc are thoroughly kneaded, formed into sheets, then containers such as cups are made by vacuum forming and/or pressure forming, e.g., so that the drawing ratio is set to over 2.0 and the periphery of the opening is curled.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention □ relates to a container, in particular, it has a white high-quality paper-like appearance, has no food hygiene problems, and has excellent incineration properties and high This invention relates to a lightweight container that can be manufactured at low cost with high productivity.

Conventionally, various types of containers for beverages, food, etc. have been known, and in particular, containers for beverage vending machines, cups for tourists, frozen confections, desserts, etc. are made of paper, synthetic resin, or Many are made of a laminate made of paper and synthetic resin. However, although paper containers are lightweight and have excellent incineration properties, they are inferior in water resistance and require a gluing process, resulting in low productivity. For this reason, synthetic resin is used for paper. Coated or laminated laminates are used, but although these have improved water resistance, the production process remains essentially the same, and productivity is low.
The runner-up is that the more laminate is used as a raw material, the more expensive it becomes. Moreover, due to the characteristics of the paper, containers made of these papers can only be made in relatively simple shapes, such as circles or squares, and the lids cannot be molded as one piece, making it difficult to adhere them. There is a drawback that it cannot be used.

For this reason, products made of various synthetic resins have recently been mass-produced by taking advantage of their thermoformability.

These synthetic resin containers are excellent in processability, light weight, and hygiene, but they are not sufficient in terms of heat resistance and rigidity. In addition, its appearance has a gloss characteristic of synthetic resins, and its hiding power and printability are poor, making it impossible to obtain a high-quality container like a paper container. Furthermore, when disposing of or incinerating these containers, the amount of calories burned is much higher than that of paper, which can damage the walls of the incinerator, cause them to melt and solidify, and depending on the type of resin, may produce toxic gas or black smoke. Incineration waste disposal has become a major social problem.

Therefore, in order to solve these problems, it has been proposed to add inorganic fillers such as calcium carbonate to thermoplastic resins, but the heat resistance and rigidity are poor, and the appearance and texture are insufficient. In addition, the filler was eluted, making it unusable for food and beverage containers due to food hygiene concerns.

As a result of extensive research into containers that have a paper-like texture, are free from food hygiene problems, and are lightweight, the inventors have found that when using specific resin compositions, these materials The present inventors have discovered that the container obtained from the method is lightweight, has sufficient strength and rigidity, has an excellent white high-grade paper-like texture, and can be manufactured continuously at low cost with high productivity, and has thus completed the present invention.

That is, the present invention uses a polyolefin resin of 3゛0 to 80
The present invention provides a container made of a resin composition material consisting of 70% to 20% talc and 70% to 20% talc.

The polyolefin resin in the present invention is not particularly limited, and includes, for example, polypropylene resin, polyethylene resin, and the like.

Examples of the polypropylene resin include propylene homopolymers, block copolymers and random copolymers of propylene and 30% by weight or less of other α-olefins such as ethylene, and mixtures thereof. Further, the melt index used is 0.19710 minutes or more, preferably 0.29/10 minutes or more. If the melt index is less than 0.1 g and 710 minutes, the melt viscosity is high and the kneading property with talc is poor.

Moreover, the moldability of the container is also poor, which is not preferable.

Furthermore, in order to manufacture the container of the present invention by thermoforming in a vacuum or compressed air column, it is necessary to use a material having a melt index of 5 g, 710 minutes or less from the viewpoint of melt strength, from the viewpoint of secondary formability. Further, the polypropylene resin can be selected as appropriate depending on the amount of talc blended, the size and shape of the container, or the purpose of use, taking into account the required heat resistance, rigidity, cold resistance, etc.

There are no particular restrictions on the polyethylene resin, including homopolymers of high-density polyethylene, medium-density polyethylene, and low-density polyethylene, carbon, ethylene, and ethylene, as well as other α-olefins such as ethylene and propylene of up to 30% by weight. There are random or block copolymers with High-density polyethylene has a density of 0.940 to 0.
970 g/cttr'', medium- and low-density polyethylenes include high-pressure polyethylene and ethylene and propylene obtained by medium- and low-pressure methods.

Copolymer with α-olefin having 3 to 12 carbon atoms such as butene-1,4-methylpentene-1, octene-1, etc.
There is so-called linear low density polyethylene. Here, a melt index of 0.02 to 10, (1/10 min, preferably 0.03 to 5.09710 min) is preferably used. However, when used only with polyethylene resin, the density is 0.93' It is preferable to use medium- to high-density polyethylene with a thickness of 0.9 cm or more, especially when forming a container from a sheet by vacuum or pressure forming.
In the present invention, it is possible to use a polyolefin resin alone, but it is also possible to vacuum form a lighter deep container. In order to carry out continuous mass production by secondary molding such as molding or pressure forming, it is effective to use a blended composition of the above-mentioned polypropylene resin and polyethylene resin. In this case, it is particularly preferable to blend 40 to 904% by weight of the polypropylene resin and 60 to 10% by weight of the polyethylene resin.

In any case, the polyolefin resin should be selected optimally depending on the amount of talc to be added later, the intended use of the container, its size, depth, shape, or its molding method. Not only various polymers and grades, but also combinations of two or more different polyolefin resins may be used.

Next, the type and shape of Merck in the present invention are not particularly limited, but it is usually hydrated magnesium silicate with an average particle size of 10 to 20μ, and its composition is 18inQ50 to 6
5%, Mg0 30-40%, and ignition loss 4-6% along with others such as OaO. The blending ratio of talc is 30 to 80% by weight of polyolefin resin and 70 to 20% by weight of talc, preferably 40 to 7% by weight of polyolefin resin.
0% by weight and Merck 60-30% by weight. If the amount of talc exceeds 70% by weight, the rigidity and incineration properties will improve, but the moldability will decrease. Particularly in thermoforming deep containers, the amount of talc blended is preferably in the range of 35 to 55% by weight.

Various types of Merck can be used, but for containers in the food-related field, it is preferable to use one that has no leached matter or odor, and can also be subjected to purification treatments such as pickling. In the present invention, by selecting crab talc among the many Ω inorganic photonic agents, it is possible to obtain a container that does not cause any problems in terms of food hygiene. Therefore, additional measures such as surface treatment are not necessary for talc, but when mechanical strength is required for non-food applications, talc whose surface has been treated to make it lipophilic is used. You can. Specific examples of these lipophilic treatments include surfactants with lipophilic groups, polymerizable monomers and oligomers that react with heating to form lipophilic groups, and even silane coupling agents. and so on.

The raw material resin composition for the container of the present invention may also include rubbers such as ethylene-propylene rubber and ethylene-propylene diene rubber, unsaturated carboxylic acids or derivatives thereof, such as polyolefins modified with anhydride and leic acid. It is also possible to add resin in a range of 0.01 to 20% by weight. Furthermore, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, pigments, etc. can also be added.

The container of the present invention is formed from the resin composition material detailed above. Although there are no particular restrictions on the method of molding the container, injection molding, blow molding, etc. may be used instead of molding, but if the composition contains a relatively large amount of talc, thin walls It is difficult to mold a molded container using these molding methods. Therefore, most commonly, polyolefin resins and talc are kneaded using conventional kneading methods, i.e., rolls, Banbury mixers, etc.
- After thorough kneading with a screw extruder, multi-screw extruder, etc., the sheet is formed into sheets of 0.4 to 3 times by a calendar method or a T-die method, and then the sheet is molded by vacuum and/or pressure forming. Next, the container is formed by thermoforming. By adopting this molding method, it is possible to mold many pieces at once, the molding cycle is short, and continuous high-volume production is possible.

・Also, in the present invention, as mentioned above, by selecting and combining resins, it is possible to obtain containers of various shapes, from shallow containers to deep containers with a 4M open magnification of 2.0 times or more, without wrinkles or uneven thickness. I can do it. In particular, it has the great feature of allowing vertically long containers such as beverage containers to be obtained.

Further, by curling the ribs around the opening of the container obtained by these thermoforming processes inwardly, girling can be easily performed and the container can be made more preferable as a beverage container.

The container of the present invention thus obtained has the following characteristics. In other words, ■ Thin wall and light weight, ■ High strength, rigidity, and heat resistance, ■ Matte white paper-like texture, ■ Odorless,
■There is no elution of the talc filler, making it highly safe in terms of food hygiene. ■High hiding power, good printability and a luxurious feel. ■Low calorific value, no damage to the furnace wall during incineration, and no melt solidification. Moreover, it does not generate toxic gas or black smoke, and has excellent waste incineration properties.

Therefore, the container of the present invention takes advantage of features that cannot be obtained with conventional synthetic resin containers, especially as beverage containers for vending machines and cups for tourists, and can replace paper cups due to its productivity, low cost, and luxurious feel. Be expected. Moreover, it does not have the design constraints that are difficult to make with paper (and because of its excellent thermoformability, it is expected to be used in fields such as frozen confections and desserts due to its flexible design.

The present invention will be further explained below with reference to Examples.

However, the present invention is not limited thereto.

Example 1 Propylene homopolymer (density 0.91 g//C+a3
．． 20 parts by weight of high-density polyethylene (density 0.96097 cm, melt index 0.5), 40 parts by weight of talc were kneaded and pelletized using a Banbury mixer, and then an extruder was used. A sheet with a size of 500 mm and a thickness of 0.8 was obtained using a pressure forming machine (3 kg, 7 cm).
) using a cup (open part diameter 73 mm, bottom diameter 51 m)
m.

It was molded at a development magnification of 4.8).

The obtained cup has an average thickness of 0.19 and thickness deviation accuracy of ±2
The cup surface was white and opaque and had a paper-like appearance.

The calorie burn rate of the container of the present invention is 5430 cal/g.
So, the calories burned in the HIPS container is 9860 cat/g.
Very low compared to 450 calories burned in paper containers
It was close to 0 cal/g.

・Also, no abnormality was observed in the container of the present invention even when the hair was soaked in boiling water at 95°C for 10 minutes. However, paper containers are immersed at 85°C for 5 minutes, causing swelling and deformation in the curling part and body-attached part, while NRP containers are immersed at 90°C for 5 minutes.
The mouth shape changed after 5 minutes of soaking, and the diameter changed from 81mm to 75mm.
It shrunk in between.

Example 2 The container having the mouth periphery obtained in Example 1 was curled using a curling machine to obtain a container with a curled mouth as shown in FIG. The curled portion of the resulting container had an excellent finished shape and was easy to work with.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of the container of the present invention. Figure M2 is a sectional view showing an example of a container subjected to curling treatment. FIG. 3 is a sectional view showing a specially designed container of the invention. Patent applicant Idemitsu Petrochemical Co., Ltd.

Claims (1)

[Claims] l) 39 to 80% by weight of polyolefin resin and Merck 7
A container made of a resin composition material containing 0 to 20% by weight. 2) The container according to claim 1, wherein the polyolefin resin is a blended resin of a polypropylene □ resin and a polyethylene resin. A container according to claim 1. 4) The container according to claim 3, which has a development magnification of 2.0 or more in vacuum forming and/or pressure forming.
. 5) A container according to claim 1, wherein the peripheral edge of the opening of the container is curled.