JP3042796B2 - Heat-resistant light-shielding barrier bottle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin bottle manufactured by stretch blow molding, and more particularly to a bottle having excellent heat resistance, light shielding properties and barrier properties.

[0002]

2. Description of the Related Art In recent years,
So-called hot filling (heating filling), which fills a polyester bottle with a liquid at 80 to 95 ° C, and pasteurizing (heat sterilization) by a hot shower, will be performed.
Therefore, excellent heat resistance has been required near the mouth of the bottle. This is because the mouth is first exposed to a hot liquid in a hot fill, and it is common to pour the hot shower from above the bottle even in pasteurizing with a hot shower.

[0003] Under such circumstances, various attempts have been made to impart heat resistance to polyester bottles.

As such an attempt, a method of producing a heat-resistant bottle by co-injecting a polyester and a heat-resistant resin to form a multilayered preformed body and subjecting it to stretch blow molding is disclosed in Japanese Patent Application Laid-Open No. Sho 63 (1988) -1988. No. -19208.
The present applicant has previously proposed that the bottles be further multi-layered by improving the co-injection method (Japanese Patent Application Nos. 1-163261 and 2-16329). These multilayer bottles have many heat-resistant resin layers especially at the mouth, and have good heat resistance.

[0005] On the other hand, many drinks such as milk drinks and lactic acid drinks deteriorate when exposed to light for a long time. Therefore, in order to prevent deterioration and guarantee quality during the period from production to consumption, it is desirable that the bottles in which they are sealed have a light-shielding property.

As such a light-shielding bottle, there is, for example, a bottle of colored glass, or a bottle in which paper is further wound around the body of the bottle. However, they are extremely restricted in design and often have poor appearance. In addition, handling is inconvenient because of its heavy weight. In addition, as a blow molded bottle, titanium white (TiO ₂ )
Is relatively excellent in light-shielding properties and is used in some cases. However, although the bottle has a high light-shielding property with respect to ultraviolet rays, a large amount of visible light is transmitted therethrough, so that the contents are easily deteriorated, and the shelf life is not sufficiently long.

[0007] Further, in the case where contents such as juices susceptible to oxygen, carbonated drinks, and foods that need to maintain freshness are contained, it is necessary to make the bottles excellent in gas barrier properties. . Some contents do not like to be mixed with moisture from the outside world, and a bottle for such contents is required to have a moisture barrier property.

Accordingly, an object of the present invention is to provide a blow-molded bottle which has heat resistance and is excellent in light-shielding properties and barrier properties.

[0009]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned objects, the present inventor has found that a blow-molded bottle has a multilayer structure comprising a polyester resin layer and a heat-resistant resin layer, and a polyester resin layer. In addition, it was discovered that by simultaneously containing a barrier resin, a light-reflective pigment and a light-absorbing pigment, it was possible to have heat resistance and excellent light-shielding properties and barrier properties, and completed the present invention. did.

That is, a heat-resistant and light-shielding bottle of the present invention comprises: a mouth; a support ring provided at a lower end of the mouth;
A shoulder portion following the support ring, a body portion and a bottom portion, the mouth portion having a multilayer structure composed of the polyester layer and the heat-resistant resin layer, and other portions being a light-shielding barrier resin layer Consisting of, the light-shielding barrier resin layer,
For 100 parts by weight of polyester, barrier resin 5.3
-19.0 parts by weight, 2.7-7.6 parts by weight of a light-reflective pigment, and 0.0054-0.019 parts by weight of a light-absorbing pigment.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a bottle according to an embodiment of the present invention. The bottle 10 includes a mouth 1, a shoulder 2, a support ring 5 provided therebetween, a body 3, and a bottom 4.
Further, the bottle 10 has a multilayer structure including a light-shielding barrier resin layer 7 and a heat-resistant resin layer 9. That is, the mouth 1
The support ring 5 has a five-layer structure including three heat-resistant resin layers 9 and two light-shielding barrier resin layers 7.
And the bottom portion 4 are formed of a single light-shielding barrier resin layer 7.

The bottle 10 is manufactured by, for example, co-injection molding a light-shielding barrier resin and a heat-resistant resin by a method exemplified in Japanese Patent Application Laid-Open No. 1-294025, and biaxially stretches the preformed body. Manufactured by blow molding. At the time of co-injection molding, the number of layers in each part after completion can be appropriately changed by changing the number of resin flow paths in the hot runner nozzle for injecting the resin and the timing of starting and stopping co-injection. .

The light-shielding barrier resin layer 7 has a matrix formed by blending a polyester resin and a barrier resin, and particles of the light-reflective pigment and particles of the light-absorbing pigment are dispersed in the matrix.

As the polyester resin, a thermoplastic resin comprising a saturated dicarboxylic acid and a saturated dihydric alcohol can be used. As the saturated dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-1,4- or 2,
Aromatic dicarboxylic acids such as 6-dicarboxylic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenyl dicarboxylic acids, diphenoxyethane diethane dicarboxylic acids, adipic acid, sebacic acid, azelaic acid, decane-1,10-dicarboxylic acid And alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Saturated dihydric alcohols include aliphatic glycols such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, dodecamethylene glycol, and neopentyl glycol. Glycols, alicyclic glycols such as cyclohexanedimethanol, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane, and other aromatic diols can be used. A preferred polyester is polyethylene terephthalate consisting of terephthalic acid and ethylene glycol.

The above polyester resin has an intrinsic viscosity of 0.5
~ 1.5, preferably in the range of 0.55-0.85. Also, such polyesters are produced by melt polymerization, 1
Those subjected to a reduced pressure treatment or a heat treatment in an inert gas atmosphere at a temperature of 80 to 250 ° C., or those obtained by solid phase polymerization to reduce the content of oligomers and acetaldehyde, which are low molecular weight polymers, are preferable.

The barrier resin is added in an amount of 5.3 to 19.0 parts by weight based on 100 parts by weight of the polyester. If the amount is less than 5.3 parts by weight, sufficient barrier properties cannot be obtained. If the amount exceeds 19.0 parts by weight, the effect is not remarkably improved, and the moldability of the resin is deteriorated. Preferred addition amount is 12.0 to 1
5.0 parts by weight. Examples of the barrier resin include oxygen, carbon dioxide, and other gas barrier properties, such as copolymerized polyester resin, polyamide resin, ethylene vinyl alcohol copolymer resin, hynitrile resin, polyacrylonitrile, acrylonitrile, methyl acrylate, and butadiene. Copolymer (trade name: Barex), polyvinyl chloride, nylon MXD6 composed of metaxylylenediamine and adipic acid, polyethylene isophthalate copolymer, various liquid crystal polyesters, and the like. It is particularly preferable to use a copolymerized polyester resin. Specifically, B010 (copolymerized polyester resin manufactured by Mitsui Pet Resin Co., Ltd.), MX nylon (Mitsubishi Gas Chemical Co., Ltd.)
Polyamide resin), XYDAR (Dartco), VECTRA (Celanese polyplastic), Econol (Sumitomo Chemical), Rodrun (Unitika), EPE (Mitsubishi Chemical), X
7G (Eastman), ULTRAX (BASF), etc.

Also, those having excellent gas barrier properties and moisture barrier properties include a blend polymer of a polyethylene copolymer (PETG) composed of terephthalic acid, ethylene glycol and cyclohexanedimethanol, and an ethylene vinyl alcohol copolymer, Blend polymers of the above PETG and polyvinyl alcohol can be used.

Polyolefin, vinyl chloride resin and the like are suitable for making a bottle having excellent moisture resistance.

Further, 2.7 to 7.6 parts by weight of a light reflective pigment is added to 100 parts by weight of the polyester. As the light-reflecting pigment, white pigments such as titanium white (TiO ₂ ), aluminum powder, mica powder, zinc sulfide, and zinc white are preferable, and it is particularly preferable to use rutile-type titanium white. When light enters the resin, the light is scattered by the particles of the light-reflective pigment. If the amount is less than 2.7 parts by weight, a sufficient light scattering effect cannot be obtained. If the amount exceeds 7.6 parts by weight, the effect is not remarkably improved even if added more, and the moldability of the resin deteriorates. The preferred content of the light reflective pigment is 4.4 to 6.7 parts by weight.

Further, 0.0054 to 0.019 parts by weight of a light-absorbing pigment is further added to 100 parts by weight of the polyester. As the light-absorbing pigment, a colored pigment such as carbon black, ceramic black, and bone black is preferable, and carbon black, which is a black pigment, is particularly preferable. Since the light scattered by the particles of the light-reflective pigment is absorbed by the particles of the light-absorbing pigment, the light does not pass through the resin. If the amount of the light-absorbing pigment is less than 0.0054 parts by weight, a sufficient light absorbing effect cannot be obtained, and if the amount exceeds 0.019 parts by weight, the effect is not remarkably improved even if added more, and the color of the resin becomes dark and the bottle becomes dark. Appearance is impaired.
The preferred content of the light absorbing pigment is 0.009 to 0.012 parts by weight.

Further, in the light-shielding barrier resin layer, in order to conceal the light-absorbing pigment and to suppress the color development, iron oxide (Fe ₂ O ₃ ) generally referred to as red iron oxide is used in an amount of 0.054 to 0.1.
It is preferred to add 27 parts by weight. If the amount is less than 0.054 parts by weight, the above effect cannot be obtained. The preferred content of iron oxide is 0.07 to 0.1 parts by weight.

Further, a lubricant, a stabilizer, an antioxidant, a thermal deterioration inhibitor, an ultraviolet ray deterioration inhibitor, an antistatic agent, an antibacterial agent, etc. are added to the light-shielding barrier resin layer within a range not to impair the object of the present invention. Agents and other resins can be added in appropriate amounts.

On the other hand, the resin constituting the heat-resistant resin layer 9 includes polyarylate, polycarbonate, polyethylene naphthalate, polyacetal, polysulfone, polyetheretherketone, polyethersulfone,
Polyetherimide, polyphenylene sulfide, a blend polymer of these resins with polyethylene terephthalate, a blend polymer of the above-mentioned heat-resistant resin, and a blend polymer of two or more kinds of the above-mentioned heat-resistant resins with polyethylene terephthalate, U A polymer (a blend polymer of polyarylate and polyethylene terephthalate, manufactured by Unitika), a polymer alloy of polyarylate and polycarbonate, and polyethylene terephthalate may be used.

[0024]

The reason why the bottle of the present invention has a sufficient light-shielding property is as follows. That is, as shown in FIG. 2, the incident light is scattered by the particles 20 of the light-reflective pigment dispersed in the light-shielding barrier resin layer 7 having a polyester resin and a barrier resin as a matrix, and the light-shielding barrier resin layer 7, the optical path becomes significantly longer. Further, since the light-absorbing pigment particles 30 are also present in the light-shielding barrier resin layer 7, the scattered light hits the light-absorbing pigment particles 30, increasing the probability of being absorbed. For this reason, even if the amount of the light-absorbing pigment is relatively small, the overall absorbance is sufficiently high. By such a principle, sufficient light-shielding properties can be obtained without using a large amount of light-absorbing pigment.

The present invention will be described in more detail with reference to the following specific examples. Example 1 Polyethylene terephthalate resin (NE made by Unitika Ltd.)
H-2050) 100 parts by weight, 13 parts by weight of copolymerized polyester resin (B010 manufactured by Mitsui Pet Resin Co., Ltd.), 6.0 parts by weight of titanium white, 0.01 part by weight of carbon black, iron oxide
A polyester resin was prepared by adding 0.09 parts by weight, 0.1 part by weight of an alkylenebisfatty acid amide and 0.16 part by weight of a higher fatty acid salt as a lubricant.

As a heat-resistant resin, a blend polymer of polyethylene terephthalate and polyarylate (U-Polymer 8400, manufactured by Unitika Ltd.) was prepared. Using the polyester resin and the heat-resistant resin, a preform was molded by coinjection molding.

Next, the preform was biaxially stretch blow-molded to produce a milky white bottle having a substantially uniform thickness of about 0.35 mm and a capacity of 925 ml. This bottle had a multilayer structure consisting of five layers as shown in FIG.

The light transmittance of the body of the bottle was measured using a spectrophotometer.
It was confirmed that the film was cut by 0% and had excellent light-shielding properties.

[0029] The bottle was heated and filled with a lactic acid beverage, sealed, stored for one year, and then subjected to a sensory test.
It was found that the taste was good and a sufficiently long shelf life was guaranteed.

[0030]

As described above, when light enters the bottle of the present invention, the particles of the light-reflective pigment in the light-shielding barrier resin layer scatter light, and the light path in the light-shielding barrier resin layer becomes longer. . Therefore, the probability that the scattered light is absorbed by the particles of the light-absorbing pigment is increased, and the light-shielding property of the bottle is improved. Therefore, the shelf life of the contents can be significantly lengthened.

Further, when iron oxide is further added to the light-shielding barrier resin layer, the coloring of the light-absorbing pigment can be suppressed, and the color tone of the bottle can be kept good.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a bottle according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a light-shielding barrier resin layer for explaining the light-shielding action of the bottle of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mouth 2 shoulder 3 trunk 4 bottom 5 support ring 7 light-shielding barrier resin layer 9 heat-resistant resin layer 10 bottle 20 light-reflective pigment particles 30 light-absorbent pigment particles

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI B32B 27/36 B32B 27/36 // B29K 67:00 B29L 9:00 22:00

Claims (5)

(57) [Claims] 1. A mouth, a support ring provided at a lower end of the mouth, a shoulder following the support ring, a body and a bottom, wherein the mouth is formed of a light-shielding barrier resin layer. In a heat-resistant light-shielding barrier bottle having a multilayer structure comprising a heat-resistant resin layer and the other part comprising a light-shielding barrier resin layer, the light-shielding barrier resin layer has a barrier property with respect to 100 parts by weight of polyester. Resin 5.3 -1
A heat-resistant, light-shielding barrier bottle comprising 9.0 parts by weight, 2.7 to 7.6 parts by weight of a light reflective pigment, and 0.0054 to 0.019 parts by weight of a light absorbing pigment. 2. The heat-resistant light-shielding barrier bottle according to claim 1, wherein the light-shielding barrier resin layer further contains 0.054 to 0.127 parts by weight of iron oxide. 3. The heat-resistant and light-shielding barrier bottle according to claim 1, wherein the barrier resin is a copolymerized polyester resin. 4. The heat-resistant and light-shielding barrier bottle according to claim 1, wherein the light-reflective pigment is titanium white. 5. The heat-resistant and light-shielding barrier bottle according to claim 1, wherein the light-absorbing pigment is carbon black.