JP2002362529A - Synthetic resin thin container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent, as a technical target, an extremely thin region from being formed on a peripheral surface due to a label edge getting into the peripheral surface of a container body, in a synthetic resin thin container formed by welding and fixing a label as an insert material to an outer peripheral surface of the molded container body, thereby preventing the peripheral wall from cracking and improving a commercial value. SOLUTION: The synthetic resin thin container comprises the synthetic resin container body which has been molded to be sufficiently thin and the label 2 welded and fixed to the outer peripheral surface of the body 1 as an insert material. The container body 1 comprises a laminate structure having its outermost layer 1c formed of a synthetic resin material with a high flexural modulus, thereby preventing the label edge 2a from getting into the peripheral wall 1a of the container body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin synthetic resin container formed by welding and fixing a label as an insert material to an outer peripheral surface of a container body to be blow-molded.

[0002]

2. Description of the Related Art As containers for refilling various liquid contents, in order to satisfy resource saving and simplification of disposal processing, the thickness of a body portion is reduced to about 0.1 to 0.7 mm, such as blow molding. Thin-walled containers made of synthetic resin formed by stretch molding, injection molding means or the like are frequently used.

[0003] Since this thin container has basically the same structure as a conventional blow-molded container or stretch blow-molded container, and also a stretch-formed container such as vacuum forming or pressure forming,
Using conventional stretch molding technology (especially blow molding technology) as it is, simply increasing the amount of stretching or reducing the size and thickness of the preform or parison stretch-molded into the container And can be suitably molded.

As a method of attaching a label to the outer peripheral surface of the thin synthetic resin container, the container main body is molded in a state where the synthetic resin label is attached as an insert material in a molding die. A method of welding and fixing a label to an outer peripheral surface of a main body is known.

[0005]

However, in the above-mentioned prior art, as shown in FIG. 3, a preform formed in a container body 1 for a mold 3 and a label 2 in a cooled state. Alternatively, since the parison is heated and stretch-formed, the inner edge 2a of the peripheral end face of the label 2 is formed.
Is a thin peripheral wall 1a of the container body 1 in a softened state.
, Thereby forming an extremely thin portion 1b which is extremely thin on the peripheral wall 1a.

[0006] Then, the stress concentration on the extremely thin portion 1b tends to cause cracks in the peripheral wall 1a from the extremely thin portion 1b, thereby causing a problem that the commercial value of the container is impaired.

Therefore, the present invention has been made to solve the above-mentioned problems in the prior art, and a label as an insert material is welded to the outer peripheral surface of a container body formed by stretch molding, injection molding or the like. In a synthetic resin thin-walled container configured to be fixed, the technical problem is to prevent the formation of an extremely thin portion on the peripheral wall due to the bite of the label edge portion with respect to the peripheral wall of the container main body. The purpose is to prevent the occurrence and improve the commercial value.

[0008]

Means for Solving the Problems According to the first aspect of the present invention for solving the above technical problems, a synthetic resin container body formed sufficiently thin and an outer peripheral surface of the container body are provided. And a label which is welded and fixed as an insert material. The container body has a laminated structure in which the outermost layer is formed of a synthetic resin material having high bending elasticity.

Since the outermost layer of the container body molded using the label as an insert material is formed of a synthetic resin material having a high flexural modulus, the peripheral wall of the container body is less likely to be bent and deformed, and the moldability is reduced. Therefore, the inner edge of the label is prevented from biting into the peripheral wall, so that the peripheral wall is never formed with an extremely thin portion, and therefore, cracks are generated on the peripheral wall due to stress concentration on the extremely thin portion. Is prevented.

A second aspect of the present invention is that, in the first aspect, the outermost layer is formed of a synthetic resin material having a flexural modulus of 3000 kg / cm ² or more.

By using a synthetic resin having a flexural modulus of not less than 3000 kg / cm ² , the inner edge of the label is prevented from biting into the peripheral wall, so that an extremely thin portion is not formed on the peripheral wall. be able to.

The means of the invention described in claim 3, 4, 5, 6, 7, 8, 9 or 10 is the same as that of claim 2,
Claim 3 is a low-density polyethylene resin, Claim 4 is a high-density polyethylene resin, Claim 5 is a polypropylene resin, Claim 6 is a nylon resin, and Claim 7 is PETG. 8 is an ethylene vinyl alcohol copolymer resin, claim 9 is a cyclic polyolefin resin, and claim 10 is a polyacrylonitrile resin. Here, PETG is amorphous PET manufactured by Eastman Chemical Company.

By forming the outermost layer using each resin, the inner edge portion of the label is prevented from biting into the peripheral wall, and therefore, the formation of an extremely thin portion on the peripheral wall can be eliminated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. The thin synthetic resin container of the present invention is sufficiently thin, preferably 0.3 to 0.5 m
m, a synthetic resin container body 1 blow-molded to a thickness of m
The container body 1 is composed of a synthetic resin label 2 welded and fixed as an insert material to the outer peripheral surface of the container body 1, and the outermost layer 1c of the container body 1 is made of ethylene vinyl alcohol copolymer (EVOH), Of polyethylene terephthalate (trade name of PETG), polypropylene (PP), and a synthetic resin material having a high flexural modulus such as nylon 66.

To form the thin container, first, FIG.
As shown in FIG. 1, a label 2 as an insert material is inserted into a predetermined position on the inner surface of a blow molding die 3 (one of the split dies is shown in FIG. 1), and then the outermost layer is bent. From a parison having a laminated structure formed of a synthetic resin material having a high elastic modulus, a bottle-shaped container main body 1 is formed by ordinary blow molding.
Is blow-molded, and thereby the peripheral wall 1a formed thin.
The label 2 is fixed to the outer peripheral surface by welding. In FIG. 1, 3
a is a cooling hole for cooling the mold 3.

In this case, the outermost layer 1c of the peripheral wall 1a
Is formed of a synthetic resin material having a high flexural modulus, so that the inner edge portion 2a of the label 2 is prevented from biting into the peripheral wall 1a. Therefore, the extremely thin portion 1b (see FIG. 3) is formed on the peripheral wall 1a. It is not formed at all, and is formed on the peripheral wall 1a having a substantially uniform thickness as a whole (see FIG. 2), so that no crack is generated.

As a method for forming a thin container, use can be made of blow molding, biaxial stretch blow molding, injection molding, vacuum molding, compressed air molding and the like.

As a label used as an insert material, a label made of a laminate sheet having a metal foil layer can be used in addition to a synthetic resin label.

Further, as a result of actual measurement of the flexural modulus required for the molding material of the outermost layer 1c of the container body 1, cracks occur at 2.2 × 10 ³ (kg / cm ² ) in the case of low-density polyethylene. It was 3.3 × 10 ^{3 for} other low-density polyethylene, and 5.5 for high-density polyethylene.
× 10 ³ , 1.4 × 10 for other high density polyethylene
⁴ , 8.2 × 10 ^{3 for} polypropylene, nylon 6
6 (2.9-8.8) × 10 ⁴ , PETG for direct blow 2.9 × 10 ⁴ , EVOH 2.5 × 10 ⁴ , cyclic polyolefin (Zeonor, manufactured by Zeon Corporation) (2.1 to 2.6) × 10 ⁴ , and in the case of polyacrylonitrile, (2.8 to 3.3) × 10 ⁴ , no crack was generated.

[0020]

Since the present invention has the above-described structure, the following effects can be obtained. Since the outermost layer of the container body molded using the label as the insert material is formed of a synthetic resin material having a high flexural modulus, the peripheral wall of the container body is hardly deformed by bending, and the moldability is reduced, so the back surface of the label is used. The side edge portion is prevented from biting into the peripheral wall, so that no extremely thin portion is formed on the peripheral wall, so that cracks are prevented from being generated on the peripheral wall due to stress concentration on the extremely thin portion. In addition, the commercial value as a thin container is improved.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of one mold of a split mold, showing a molding example of the container of the present invention.

FIG. 2 is an enlarged plan sectional view of a main part showing a state after blow molding of the molding example shown in FIG. 1;

FIG. 3 is an enlarged plan sectional view of a main part showing a state after blow molding by a conventional molding method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Container main body 1a; Peripheral wall 1b; Extra-thin part 1c; Outermost layer 2; Label 2a; Inside edge part 3;

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E033 AA01 BA14 BA15 BA16 BA18 BA21 BA23 BB08 CA20 EA20 FA03 3E062 AA09 AB01 AC02 DA02 DA07

Claims (10)

[Claims] A container comprising a synthetic resin container main body (1) formed sufficiently thin and a label (2) welded and fixed as an insert material to an outer peripheral surface of the container main body (1). The container body (1) is a thin synthetic resin container having a laminated structure in which the outermost layer (1c) is formed of a synthetic resin material having a high flexural modulus. 2. An outermost layer (1c) formed of a synthetic resin material having a flexural modulus of 3000 kg / cm ² or more.
A thin container made of the synthetic resin described in the above. 3. A thin container made of synthetic resin according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a low-density polyethylene resin. 4. The thin synthetic resin container according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a high-density polyethylene resin. 5. The thin container made of a synthetic resin according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a polypropylene resin. 6. The thin synthetic resin container according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a nylon resin. 7. The synthetic resin material forming the outermost layer (1c) is P
The thin container made of a synthetic resin according to claim 2, which is ETG. 8. The thin container made of a synthetic resin according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is an ethylene vinyl alcohol copolymer resin. 9. The thin synthetic resin container according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a cyclic polyolefin resin. 10. The thin container made of a synthetic resin according to claim 2, wherein the synthetic resin material forming the outermost layer (1c) is a polyacrylonitrile resin.