JPH04272826A - Bottle of heat-resistant light shielding barrier properties - Google Patents

Abstract

PURPOSE:To manufacture a blow molded bottle of heat-resistance and also of superior light shielding properties and barrier properties. CONSTITUTION:A bottle is provided with a cap 1, a support ring 5 disposed at the lower end of said cap, a shoulder section 2 formed successively to the support ring, a body 3 and a bottom 4, and the cap 1 is of multi-layer structure composed of a light shielding barrier resin layer 7 and a heat-resistant resin layer 9, while sections other than the cap are composed of the light shielding resin layers 7. The light shielding barrier resin layer is composed of resin containing 5.3-19.0 pts.wt. of barrier resin, 2.7-7.6 pts.wt. of a light reflective pigment and 0.0054-0.019 pts.wt. of a light absorbing pigment to 100 pts.wt. of polyester.

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

[Prior art and problems to be solved by the invention] In recent years,
So-called hot fill (heat filling), in which polyester bottles are filled with liquid at 80 to 95°C, and pastelizing (heat sterilization) using hot showers, have created excellent heat resistance near the mouth of the bottle. It has become required. This is because in hot fill, the mouth is first exposed to the hot liquid, and in hot shower pasteurizing, the hot shower is generally poured from the top of the bottle.

Under these circumstances, various attempts have been made to impart heat resistance to polyester bottles.

[0004] As an attempt at such a method, a method of manufacturing a heat-resistant bottle by co-injecting polyester and a heat-resistant resin to form a multilayered preform and stretch-blow molding the preform was disclosed in Japanese Patent Application Laid-Open No. 63 -19208. Furthermore, the present applicant has previously proposed making the bottle even more 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 in the mouth, and have good heat resistance.

On the other hand, many beverages 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 manufacture to consumption, it is desirable that the bottle in which they are enclosed has light-shielding properties.

[0006] Examples of such light-shielding bottles include bottles made of colored glass, bottles whose bodies are further wrapped with paper, and the like. However, their designs are extremely limited, and many of them are inferior in appearance. In addition, it is heavy, making it inconvenient to handle. We also use titanium white (Ti) on polystyrene as blow molded bottles.
Products made from resin in which O2) is dispersed have relatively excellent light-shielding properties and are used in some cases. However, although these bottles have high UV blocking properties, a large amount of visible light passes through them, so the contents tend to deteriorate and the shelf life is not long enough.

[0007]Furthermore, if the contents are juices, carbonated drinks, etc. that are susceptible to the effects of oxygen, or foods that need to be kept fresh, it is necessary to use a bottle with excellent gas barrier properties. . Furthermore, depending on the contents, there are some that do not like moisture from the outside world to enter into the bottle, and bottles for such contents are required to have moisture barrier properties.

[0008] Accordingly, an object of the present invention is to provide a blow-molded bottle that is heat resistant and has excellent light shielding and barrier properties.

[0009]

[Means for Solving the Problems] In view of the above object, as a result of intensive research, the present inventor has created a blow-molded bottle with a multilayer structure consisting of a layer of polyester resin and a layer of heat-resistant resin, and a layer of polyester resin. discovered that by simultaneously containing a barrier resin, a light-reflecting pigment, and a light-absorbing pigment, it was possible to create a product that had heat resistance and excellent light blocking and barrier properties, and completed the present invention. did.

That is, the heat-resistant and light-shielding bottle of the present invention includes a mouth, a support ring provided at the lower end of the mouth,
It has a shoulder part following the support ring, a body part, and a bottom part, and the mouth part has a multilayer structure consisting of the polyester layer and the heat-resistant resin layer, and the other part has a light-blocking barrier resin layer. The light-shielding barrier resin layer consists of:
Per 100 parts by weight of polyester, 5.3 to 19.0 parts by weight of barrier resin and 2.7 to 19.0 parts by weight of light reflective pigment.
7.6 parts by weight and 0.0054 to 0.0 light-absorbing pigment
19 parts by weight.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a bottle according to an embodiment of the present invention. The bottle 10 consists of a mouth part 1, a shoulder part 2, a support ring 5 provided between them, a body part 3, and a bottom part 4. Further, the bottle 10 has a multilayer structure consisting of a light-blocking barrier resin layer 7 and a heat-resistant resin layer 9. That is, the mouth part 1 and the support ring 5 have a five-layer structure consisting of three heat-resistant resin layers 9 and two light-shielding barrier resin layers 7, and the body part 3 and the bottom part 4 have a one-layer light-shielding barrier resin layer. It consists of a synthetic resin layer 7.

[0012] The bottle 10 is, for example, disclosed in Japanese Patent Application Laid-Open No. 1-2940.
A preform is produced by co-injection molding a light-shielding barrier resin and a heat-resistant resin by the method exemplified in No. 25, and the preform is biaxially stretched and blow-molded. During co-injection molding, by changing the number of resin flow channels in the hot runner nozzle that injects the resin and the timing of starting and stopping co-injection, the number of layers in each part after completion can be changed as appropriate. .

The light-shielding barrier resin layer 7 has a matrix made of a blend of a polyester resin and a barrier resin, and particles of a light-reflecting pigment and particles of a light-absorbing pigment are dispersed in the matrix.

[0014] As the polyester resin, a thermoplastic resin consisting of a saturated dicarboxylic acid and a saturated dihydric alcohol can be used. Saturated dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-1,4-
or 2,6-dicarboxylic acid, diphenyl ether-4,
Aromatic dicarboxylic acids such as 4'-dicarboxylic acid, diphenyl dicarboxylic acids, diphenoxyethane diethanedicarboxylic acids, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, decane-1,10-dicarboxylic acid, cyclohexane dicarboxylic acid Alicyclic dicarboxylic acids such as acids can be used. Saturated dihydric alcohols include ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol, polyethylene glycol,
Aliphatic glycols such as polypropylene glycol, polytetramethylene glycol, hexamethylene glycol, dodecamethylene glycol, neopentyl glycol, alicyclic glycols such as cyclohexanedimethanol, 2,2-bis(4'-β-hydroxyethoxyphenyl) ) Propane, other aromatic diols, etc. can be used. A preferred polyester is polyethylene terephthalate consisting of terephthalic acid and ethylene glycol.

[0015] The above polyester resin has an intrinsic viscosity of 0
．． 5 to 1.5, preferably 0.55 to 0.85. In addition, such polyesters are those produced by melt polymerization and heat treated at a temperature of 180 to 250 °C under reduced pressure or in an inert gas atmosphere, or those produced by solid phase polymerization to produce low molecular weight polymers such as oligomers and acetaldehyde. Those with reduced content are preferred.

[0016] 5.3 to 19.0 parts by weight of barrier resin is added to 100 parts by weight of the above polyester. If it is less than 5.3 parts by weight, sufficient barrier properties cannot be obtained, and if it exceeds 19.0 parts by weight, the effect will not be significantly improved even if it is added in excess of 19.0 parts by weight, and the moldability of the resin will deteriorate. The preferred amount added is 12.0 to 15.0 parts by weight. Examples of barrier resins include copolyester resins, polyamide resins, ethylene vinyl alcohol copolymer resins, high nitrile resins, polyacrylonitrile, and acrylonitrile, methyl acrylate, and butadiene. Copolymer (
Product name: Valex), polyvinyl chloride, nylon MXD6 consisting of metaxylylene diamine and adipic acid,
Examples include polyethylene isophthalate copolymers and various liquid crystal polyesters. In particular, it is preferable to use a copolymerized polyester resin. Specifically, B010
(copolyester resin manufactured by Mitsui Pet Resin Co., Ltd.), MX nylon (polyamide resin manufactured by Mitsubishi Gas Chemical Co., Ltd.), XYDAR (manufactured by Dartco), VECTRA
(made of Celanese polyplastic), Econor (
(manufactured by Sumitomo Chemical), Rodrun (manufactured by Unitika), EP
E (manufactured by Mitsubishi Kasei), X7G (manufactured by Eastman), UL
There are TRAX (manufactured by BASF), etc.

[0017] Examples of materials that have excellent both gas barrier properties and moisture barrier properties include blend polymers of polyethylene copolymers (PETG) consisting of terephthalic acid, ethylene glycol and cyclohexanedimethanol, and ethylene vinyl alcohol copolymers; The above PETG
Blend polymers of polyvinyl alcohol and polyvinyl alcohol can be used.

[0018] Polyolefin, vinyl chloride resin, etc. are suitable for making a bottle with excellent moisture resistance.

Furthermore, 2.7 to 7.6 parts by weight of a light-reflecting pigment is added to 100 parts by weight of the above polyester. Titanium white (TiO
2) White pigments such as 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, it is scattered by particles of the light-reflective pigment. If it is less than 2.7 parts by weight, a sufficient light scattering effect cannot be obtained;
If it exceeds 1 part by weight, the effect will not be significantly improved even if it is added in excess, and the moldability of the resin will deteriorate. The preferred content of the light-reflecting pigment is 4.4 to 6.7 parts by weight.

[0020] Furthermore, 0.0054 to 0.01 of a light-absorbing pigment is added to 100 parts by weight of the above polyester.
Add 9 parts by weight. As the light-absorbing pigment, colored pigments such as carbon black, ceramic black, and bone black are preferable, and it is particularly preferable to use carbon black, which is a black pigment. The light scattered by the light-reflecting pigment particles is absorbed by the light-absorbing pigment particles, so that the light does not pass through the resin. Light absorbing pigment is 0.0
If it is less than 0.054 parts by weight, a sufficient light absorption effect cannot be obtained,
If it exceeds 0.019 parts by weight, the effect will not be significantly improved even if it is added further, and the color of the resin will darken, impairing the appearance of the bottle. The preferred content of light-absorbing pigment is 0.009 to 0.0
12 parts by weight.

Furthermore, in the light-shielding barrier resin layer, 0.054 to 0.127 of iron oxide (Fe 2 O 3 ), generally called red iron oxide, is added in order to hide the light-absorbing pigment and suppress its color development. It is preferable to add parts by weight. If the amount is less than 0.054 parts by weight, the above effects cannot be obtained, and if it exceeds 0.127 parts by weight, coloring due to iron oxide becomes significant and the appearance of the bottle is impaired. The preferred content of iron oxide is 0.07 to 0.1 parts by weight.

Furthermore, lubricants, stabilizers, antioxidants, heat deterioration inhibitors, ultraviolet deterioration inhibitors, antistatic agents, antibacterial agents, etc. may be added to the light-shielding barrier resin layer within a range that does not impair the purpose of the present invention. Appropriate amounts of agents and other resins can be added.

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 and polyethylene terephthalate, a blend polymer of the above heat-resistant resins, and a blend polymer of two or more of the above heat-resistant resins and polyethylene terephthalate, U Polymers (manufactured by Unitika, blend polymer of polyarylate and polyethylene terephthalate), polymer alloys of polyarylate, polycarbonate, and polyethylene terephthalate, etc. can be used.

[0024]

[Function] The reason why the bottle of the present invention has sufficient light-shielding properties is considered to be due to the following reasons. That is, as shown in FIG. 2, the incident light is scattered by the light-reflecting pigment particles 20 dispersed in the light-blocking barrier resin layer 7, which has a matrix of polyester resin and barrier resin. 7, the optical path becomes significantly longer. Furthermore, since 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 and has a high probability of being absorbed. Therefore, even if the amount of light-absorbing pigment is relatively small, the absorbance as a whole can be sufficiently high. Based on this principle, sufficient light-shielding properties can be obtained without using a large amount of light-absorbing pigment.

The present invention will be explained in more detail with reference to the following specific examples. Example 1 Polyethylene terephthalate resin (Unitika Co., Ltd. N)
EH-2050) 100 parts by weight, copolyester resin (Mitsui Pet Resin Co., Ltd. B010) 1
3 parts by weight, 6.0 parts by weight of titanium white, 0.01 parts by weight of carbon black, 0.09 parts by weight of iron oxide, and 0.1 parts by weight of alkylene bis fatty acid amide and 0.16 parts by weight of higher fatty acid salts as lubricants. was added to prepare a polyester resin.

A blend polymer of polyethylene terephthalate and polyarylate (U Polymer 8400, manufactured by Unitika Co., Ltd.) was also prepared as a heat-resistant resin. A preform was molded by co-injection molding using the above polyester resin and heat-resistant resin.

Next, this preform was subjected to biaxial stretch blow molding to produce a milky white bottle having a substantially uniform wall thickness of about 0.35 mm and a capacity of 925 ml. The mouth of this bottle had a multilayered structure consisting of five layers, as shown in FIG.

[0028] When the light transmittance of the body of this bottle was measured using a spectrophotometer, it was confirmed that it blocked 100% of light with a wavelength of 600 nm or less, and had excellent light-shielding properties.

[0029] In addition, after heating and sealing the lactic acid beverage in this bottle and storing it for one year, a sensory test was conducted.
It was confirmed that the product exhibited good taste and had a sufficiently long shelf life.

[0030]

[Effects of the Invention] As explained above, when light enters the bottle of the present invention, the particles of the light-reflecting pigment in the light-blocking barrier resin layer scatter the light, and the optical path in the light-blocking barrier resin layer becomes longer. . Therefore, the probability that the scattered light will be absorbed by the light-absorbing pigment particles increases, and the light-shielding properties of the bottle improve. Therefore, the shelf life of the contents can be significantly extended.

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 of the bottle can be kept good.

[Brief explanation of the drawing]

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

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

[Explanation of symbols]

1 Mouth 2 Shoulder 3 Torso 4 Bottom 5 Support ring 7. Light-shielding barrier resin layer 9 Heat-resistant resin layer 10 bottles 20 Light reflective pigment particles 30 Light-absorbing pigment particles

Claims (5)

[Claims] 1. A mouth part, a support ring provided at the lower end of the mouth part, and a shoulder part continuing from the support ring.
In a heat-resistant and light-blocking barrier bottle, the bottle has a body and a bottom, the mouth has a multilayer structure consisting of a light-blocking barrier resin layer and a heat-resistant resin layer, and the other parts have a light-blocking barrier resin layer. , the light-shielding barrier resin layer contains 5 parts by weight of barrier resin per 100 parts by weight of polyester.
．． 3 to 19.0 parts by weight, and 2.7 to 7 parts by weight of light reflective pigment.
．． 6 parts by weight and 0.0054 to 0.01 of the light-absorbing pigment
9 parts by weight of a heat-resistant light-shielding barrier bottle. 2. The heat-resistant light-blocking barrier bottle according to claim 1, wherein the light-blocking barrier resin layer further contains 0.054 to 0.127 parts by weight of iron oxide. Bottle. 3. The heat-resistant light-shielding barrier bottle according to claim 1 or 2, wherein the barrier resin is a copolymerized polyester resin. 4. The heat-resistant light-blocking barrier bottle according to claim 1, wherein the light-reflecting pigment is titanium white. 5. The heat-resistant light-blocking barrier bottle according to claim 1, wherein the light-absorbing pigment is carbon black.