JPH06210708A - Multilayered resin container - Google Patents

Abstract

PURPOSE:To inexpensively provide a resin container capable of being colored without being affected by the color of content or damaging appearance, capable of blocking the effect of the offensive smell of the pearl gloss layer of an outer layer, having excellent pearl gloss appearance or pottery like appearance and receiving cosmetics, a shampoo, a rinse, food or medicines. CONSTITUTION:In a multilayered container produced by the direct blow molding of a thermoplastic resin, the outermost layer 1 of the container is composed of a compsn. consisting of a polyester resin 70-96.5wt.% and a methacrylic resin 3.5-30wt.%. An opaque, white or colored thermoplastic resin layer is provided to an intermediate layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for storing cosmetics, shampoos, rinses, foods, medicines, etc. having a beautiful appearance such as pearly luster and ceramics.

[0002]

2. Description of the Related Art Conventionally, the following methods have been carried out in order to impart a pearlescent or porcelain-like beautiful appearance to a container in which appearance is important. In the case of expressing pearl luster, a pearl luster expressing agent, for example, guanine of fish scale, talc powder, various lead salts, mica, titanium-like pearlescent agent, etc. is applied to the surface of the object as a paint or kneaded. It was common for this to happen. In addition, as another method, Japanese Patent Publication No. 62-24253.
As shown in, the thermoplastic polyester resin 99.5
Known is a plastic cosmetic bottle obtained by stretch blow molding a mixture of 90% by weight and 0.5 to 10% by weight of methacrylic resin at a stretching temperature of 80 to 160 ° C. and a total stretching ratio of 1.33 to 20. Has been.

Further, as shown in Japanese Patent Publication No. 62-20889, blow molding is carried out using a resin composition comprising 60 to 99.5% of polyester resin and 40 to 0.5% by weight of colored methacrylic resin. There is a polyester resin cosmetic bottle with a pearly surface gloss and surface flow pattern obtained. That is, 60 to 99.5 wt% of polyester resin and 40 to 0.5 wt% of colored methacrylic resin pellets extruded by adding an organic pigment and / or an organic dye to methacrylic resin are mixed and extruded. A polyester cosmetic product having a colored pearl-like surface gloss and a surface flow pattern, which is characterized by molding the mixed resin composition into pellets, injection-molding the pellets into a preform, and then blow-molding the preform. There is a bottle manufacturing method.

Further, as shown in JP-B-57-98327, a resin obtained by blending a thermoplastic polyester resin with at least one selected from the group consisting of a methacrylic resin, a saturated aliphatic polyolefin resin and a styrene resin. A polyester hollow container made of the composition and biaxially stretch blow-molded and having a matte-treated matte pearly luster is also known.

However, the method of coating or kneading the pearlescent agent is such that the pearlescent agent is located on the surface and exhibits pearly gloss, so that a deep pearly luster cannot be obtained and an expensive pearlescent pearlescent agent is not obtained. It has a drawback that the cost is increased due to the gloss developing agent. Further, the conventional technique is to form a single layer of a transparent resin composition by adding a transparent methacrylic resin to a transparent polyester resin by stretch blow molding, and orient the transparent resin in a certain direction on the surface of the container, Since the pearl luster is expressed by the diffuse reflection of light from transparent resins with different light refractive indexes, the color tone of the contents filled in the container, especially when the transparent contents are filled, the pearl luster of the container is significantly impaired due to the influence of the contents. There is. For this reason, the color tone of the contents to be filled is considerably limited in order to take advantage of the pearl luster of the container.

Further, since the colored container is stretched to develop a pearlescent color, a darkly colored ring-shaped boundary between the stretched body and shoulders and the neck of the unstretched container is conspicuous and the appearance is significantly impaired. Had limited coloring. Also,
Stretch blow molding requires two types of molds, a primary molding die and a stretch blow molding die, and molding equipment for each, and the equipment cost and die cost are high, so mass production is required to reduce the cost of the container. Further, in order to reduce the mold cost, it is necessary to standardize and unify the primary molding dies, which limits the size of the bottle mouth. In addition, conventional pearlescent resins obtained by adding other resins to polyester resins such as methacrylic resins and stretch-blow molding may cause odors in the added resins, and the contents filled in bottles may be odorous. There were some drawbacks such as being affected.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to perform coloring without being limited to the color of the contents and without impairing the appearance, and to improve the appearance of the pearlescent resin of the outer layer. It is an object to provide a resin container for storing cosmetics, shampoo, conditioner, food, medicine, etc., which has an excellent pearly luster and a porcelain-like appearance capable of blocking the influence of odor, at low cost.

[0008]

In order to solve the above problems, the present invention is a multi-layer container in which a thermoplastic resin is directly blow-molded, and the outermost layer of the container is 70 to 96.5 weight parts of polyester resin. % Of methacrylic resin 3.5 to
A resin container made of a composition added with 30% by weight. Moreover, it is the said resin container which has an opaque white or colored thermoplastic resin layer in an intermediate | middle layer.

The polyester resin used in the present invention is a generally known polyester resin used in direct blow molding, and its main object is polyethylene terephthalate. As a part of the component of terephthalic acid, for example, isophthalic acid or naphthalenedicarboxylic acid. Aromatic dicarboxylic acids such as diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid; alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, etc .; other difunctional carboxylic acids such as p-β-hydroxyethoxybenzoic acid, oxy acids such as ε-oxycaproic acid and / or ethylene glycol components Part of As, for example, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentylene glycol, diethylene glycol, triethylene glycol, 1.1-cyclohexanedimethylol, 1.4-cyclohexanedimethylol, 2.2- Bis (4-β-hydroxyethoxyphenyl) propane, bis (4-β-
It may be a copolymer of one or more polyfunctional compounds such as other glycols such as hydroxyethoxyphenyl) sulfone and functional derivatives thereof.
The polyester resin used in the present invention may be any polyester resin capable of direct blow molding.

The methacrylic resin used in the present invention is
It may be a homopolymer of methyl methacrylate, a copolymer of 50% mol or more of methyl methacrylate and another vinyl monomer, or a mixture of these polymers. Other vinyl monomers that can be copolymerized with methyl methacrylate include alkyl acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate, acrylonitrile, methacrylonitrile, styrene, and α-methylstyrene. . In the present invention, when a homopolymer of methyl methacrylate or a copolymer with methyl acrylate or ethyl acrylate is used, a resin container having a particularly excellent pearlescent or ceramic appearance can be obtained, which is preferable. is there.

The method for blending the polyester resin and the methacrylic resin in the present invention is to mix the respective resins and then pelletize them by an extrusion molding machine, or directly supply these resins to a direct blow molding machine for molding. For example, a generally known method may be arbitrarily used.

In the present invention, it is optional to add additives such as dyes and pigments, ultraviolet absorbers and antistatic agents to the resin composition comprising polyester resin and methacrylic resin within the scope of the present invention. .

The multi-layer direct blow container is a direct blow bottle consisting of two or more layers, and is a bottle for obtaining a property which cannot be obtained by a single material by multi-layering. For example, the blow bottle is provided with appearance improvement, gas barrier property, convenience, and low burning calories by adding a filler filling layer. Therefore, the multi-layer direct blow container in the present invention is a multi-layer direct blow bottle having two or more layers composed of the same or different resins depending on the purpose, and if the outer layer is a composition containing the polyester resin described in the claims. The container may have any configuration.

In addition, in the case where the contents are colored, it is important to use an opaque white or colored thermoplastic resin for the intermediate layer in order to avoid the influence of the colors of the contents. By doing so, since the color tone of the intermediate layer is seen through the outermost transparent pearlescent layer, the pearlescent effect is further enhanced.

An example of the layer structure of the multilayer direct blow container of the present invention will be described with reference to the drawings. However, it is not limited to these. FIG. 1 shows a resin composition comprising a polyester resin and a methacrylic resin as an outer layer 1, an ethylene-α-olefin copolymer acid modified product as an adhesive layer 2, an opaquely colored polyolefin resin as an intermediate layer 3, and an inner layer. 4 is a multi-layer container composed of a polyolefin resin. FIG. 2 shows a multi-layer container in which a resin composition comprising a polyester resin and a methacrylic resin is used for the outer layer 1, a gas barrier resin layer is used for the intermediate layer 3, and a polyolefin resin layer is used for the inner layer 4. When the adhesiveness of the resin contacting the gas barrier resin is weak, an adhesive layer may be provided. Figure 3
A multilayer container having a structure in which a resin composition comprising a polyester resin and a methacrylic resin is used for the outer layer 1 and a barrier layer is provided for the inner layer 4.

[0016]

Since the present invention is a resin composition in which 3.5 to 30% of an acrylic resin is mixed with a polyester resin, excellent physical properties such as gloss of the polyester resin, moldability and transparency are retained. While, the pearlescent luster by the addition of acrylic resin, porcelain-like appearance, as a multi-layer container, gas barrier resin in the inner layer or the intermediate layer, low combustion calorie resin by the addition of a filler filling layer, by laminating polyolefin resin, It is possible to obtain a pearly luster and a ceramic luster resin container having desired properties such as gas barrier properties, low burning calorie properties, and strength reinforcing properties.

Further, as in the invention of claim 2, by providing an opaque white or colored thermoplastic resin layer in the intermediate layer, the pearl colored in any color without being affected by the color of the contents. It is possible to obtain a glossy, ceramic-like glossy resin container by blow molding instead of stretch blow molding. Even if the bottle is colored, unlike the conventional pearlescent and ceramic-like containers obtained by stretch blow molding with a transparent polyerter resin-containing composition, pearls that are not stretched by direct blow molding are used. To express luster,
There will be no flow mark-like dark borders or the like appearing on the bottle neck and spoiling the appearance.

Furthermore, the quality assurance of the contents is improved. That is, since the container of the pearlescent resin obtained by stretch blow molding a composition obtained by adding a transparent resin to a conventional polyester resin has a single layer, a molded container may be different depending on the added resin. A resin odor may be generated and filled, and the contents may be adversely affected. For example, when a methacrylic resin is blended, a resin odor peculiar to methacrylic resin may be generated, and it may not be used for cosmetics, shampoos, rinses, and other products where fragrance is important. In the multilayer direct blow molding container of the present invention, even if the outer layer has a resin odor, the resin of the middle layer and the inner layer can shield the content from the resin odor and guarantee the quality of the content.

[0019]

EXAMPLE A sheet of PET-G, which is a polyester resin, was blended with a methacrylic resin as described below, and the pearl luster and the light transmittance of the sheet were measured from the appearance. (Prototype of sheet) Polyester resin; Kodar Copolyest
er PET-G 6763 Eastman Chem
Methacrylic resin manufactured by ical Products; Parapet G 1000 Kuraray Co., Ltd. sheet prototype; Labo Plastmill Mod
el 30 3150 (manufactured by Toyo Seiki Seisakusho Co., Ltd. (prototype result)) The results obtained by observing the pearl luster from the appearance of a prototype sheet having a thickness of about 0.5 mm are as shown in (Table 1).

[0020]

[Table 1]

When 50% of methacrylic resin is added, the gloss unique to polyester resin is lost. Moreover, the trial-made sheet easily has a weak cracking strength by hand. When 1.0% is added, it becomes slightly cloudy but becomes transparent, resulting in impaired pearl luster.

Table 2 shows data obtained by measuring the light transmittance of the prototype sheet. Measuring instrument: Spectrophotometer (Co., Ltd.)
Shimadzu) Measuring wavelength: 800nm

[0023]

[Table 2]

The results of calculating the absorption index from the obtained light transmittance from the Lambert Beer's law are as shown in Table 3. (Lambert-Beer equation) -log I / I ₀ = -log T = At = τb I ₀ ; light intensity before transmission I; light intensity after transmission T; transmittance At; extinction index τ; turbidity coefficient b; thickness It

[0025]

[Table 3]

Since the pearly luster of the sheet has a correlation with the absorption index, the addition amount of the methacrylic resin and the absorption index are shown in FIG.

(Prototype of Multilayer Direct Blow Bottle) In order to confirm the case where the results of the above-described trial production of the sheet were applied to a container, a multilayer direct blow bottle was prototyped and the appearance and drop strength of the bottle were confirmed. Prototype bottle Capacity: 220 ml Shape: Ellipse Height: 170 mm Cross-section of body (height of 6 cm from the bottom) 62 x 36 mm Composition of bottle: Outer layer: Polyester resin with methacrylic resin 1.0 to 5
Resin composition with 0% by weight added Adhesive layer: Ethylene-α olefin copolymer acid modified product Intermediate layer: High-density polyethylene (pink, green, white is opaquely colored) Inner layer: High-density polyethylene (uncolored) 4).

[0028]

[Table 4]

The bottle using the resin composition having 3.5 to 30% by weight added to the outer layer has a good appearance. The resin composition added with 1.0% by weight is slightly clouded, but has no pearlescent luster. 5
When 0% by weight is added, the surface gloss is impaired and the appearance is poor. The white colored bottle had a beautiful white porcelain tone. In addition, the bottles colored pink and green exhibited a beautiful pearl luster without uneven color. Furthermore, although the transparent colored contents were filled, the color of the contents was blocked by the intermediate layer in any of the prototype bottles, and the color tone of the bottles was not impaired.

(Drop strength test) Test conditions: In order to confirm the strength of the prototype bottles, each 5 bottles were left at a temperature of 5 ° C. for 16 hours, and then dropped from an elevation of 1 m upright on concrete 5 times. Defeated Result: 1.0 to 15% by weight additive product dropped 5 times without any change. The 30% by weight additive product dropped 4 to 5 times, and there was a bottle that cracked in the outer layer of the pinch-off portion at the bottom of the bottle, but the filled contents did not leak and there was no practical problem. 50% by weight
Additives cause a significant crack at the bottom of the bottle with one drop,
There are practical problems. Therefore, it is considered that there is a problem in practical use because the product added with 50% by weight has poor appearance and gloss.

[0031]

INDUSTRIAL APPLICABILITY The present invention provides a multilayer direct blow resin container using a pearlescent resin composition obtained by adding 3.5 to 30% by weight of a methacrylic resin composition to a polyester resin for direct blowing as an outer layer. Therefore, the pearl luster can be imparted to the bottle while maintaining the excellent physical properties and moldability of the polyester resin. Further, by adding a coloring agent to the resin composition of the outer layer, a porcelain-like jar and a bottle excellent in color and excellent in appearance can be formed. Further, because of the multi-layer structure, it is possible to reinforce the decrease in strength of the resin composition of the outer layer due to the addition of the acrylic resin to the polyester resin by the resin of the intermediate layer or the inner layer. In addition, the colorability of the bottle is significantly improved. That is, a pearlescent resin obtained by blending a conventional polyester resin with a transparent resin and stretch-blow molding, when colored, has a ring-shaped dark color at the boundary between the unstretched neck and the stretched shoulder or body. A colored ring is formed and the appearance is significantly impaired. Since the present invention is a direct blow, the pearlescent luster does not have a difference in color development depending on the part, and since it is a multi-layer even if the intermediate layer and the inner layer are colored, it is not directly related to the pearlescent color development and color tone of the outer layer, It does not affect the appearance of pearly luster or create a ring at the border of the neck of a colored bottle that impairs the appearance. Further, the relatively expensive polyester-based resin can be used only in the outer layer, and therefore the amount thereof can be reduced, and the cost can be reduced because an inexpensive general-purpose resin can be used in the intermediate layer and the inner layer. Further, since the equipment cost and the die cost are lower than those of the stretch blow molding, the cost is low and the multi-product small-volume molding is possible. Further, the content guarantee property is improved. Since the conventional pearlescent resin obtained by stretch blow molding is composed of a single resin composition, an acrylic odor may be generated when a resin that easily generates a resin odor, for example, a methacrylic resin is added. (References;
JP-B-61-39336 Table-7) In such cases, bottles may not be used for cosmetics, shampoos, rinses and other products where the scent is important. The multi-layer blow-molded pearlescent resin has only an outer layer even if the pearlescent resin has an odor, so that the middle layer and the inner layer can block off the odor and guarantee a middle scent.

[0032]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a layer configuration example of a multilayer resin container of the present invention.

FIG. 2 is an explanatory diagram showing a layer configuration example of the multilayer resin container of the present invention.

FIG. 3 is an explanatory diagram showing a layer configuration example of the multilayer resin container of the present invention.

FIG. 4 is a graph showing the relationship between the amount of methacrylic resin added and the absorption index.

[Explanation of symbols]

 1 ... Outer layer 2 ... Adhesive layer 3 ... Intermediate layer 4 ... Inner layer

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[Procedure amendment]

[Submission date] November 4, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

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[0002]

2. Description of the Related Art Conventionally, the following methods have been carried out in order to impart a pearlescent or porcelain-like beautiful appearance to a container in which appearance is important. In the case of expressing pearl luster, a pearl luster expressing agent, for example, guanine of fish scales, talc powder, various lead salts, mica, titanium-based pearl agents, or the like, is applied to the surface of the object as a paint or kneaded. It was common for this to happen. Also, as another method, Japanese Patent Publication No. 61-24253.
As shown in No. 3, thermoplastic polyester resin 99.5
To 90% by weight and 0.5 to 10% by weight of a methacrylic resin are stretch blow-molded at a stretching temperature of 80 to 160 ° C. and a total stretching ratio of 1.33 to 20 to obtain a plastic cosmetic bottle. Are known.

[Procedure Amendment 2]

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[Correction method] Change

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[Figure 1]

[Procedure 3]

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Claims (2)

[Claims] 1. A multilayer container for direct blow molding of a thermoplastic resin, wherein the outermost layer of the container is polyester resin 70 to 96.5% by weight and methacrylic resin 3.5 to.
A multi-layer resin container comprising a composition containing 30% by weight. 2. The multilayer resin container according to claim 1, which has an opaque white or colored thermoplastic resin layer as an intermediate layer of the container.