JP2005219760A - Multilayer structure resin container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer structure resin container which keeps a good appearance as a cosmetic container or the like, enables the reuse or recycle of forming wastes or rejects generated in forming during a forming process, and is manufactured by direct-blow-molding appropriate for production of many kinds in a small quantity. <P>SOLUTION: In the container of a multilayer structure consisting of at least two layers by forming a thermoplastic synthetic resin by direct blowing, a transparent polyethylene terephthalate resin is used as a resin material of an outermost layer 2 forming the exterior of a container body 1, and a polyethylene terephthalate resin exhibiting an alabaster color or a ceramic color by blending a coloring agent is used in an internal layer 3 in contact with the outermost layer 2. In addition, a pearly gloss or a luminous gloss is exhibited by blending a pearly brighter or a luminous coloring agent in the internal layer 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer structure resin container by direct blow molding that is excellent in appearance as a cosmetic container or the like, and can recycle or recycle molding waste or defective products generated during molding in a molding process.

  Synthetic resin containers are lighter than glass bottles, and are superior in impact resistance and other physical properties, so instead of glass containers, cosmetic containers, food containers, pharmaceutical containers, etc. Widely used.

In order to obtain a resin container that requires a more beautiful appearance design than before, the following method has been employed. In other words, in order to give gloss to the surface of the resin container, it adheres to the polyester resin and the intermediate layer as the outermost layer resin of a biaxial stretch blow molded PET container made of polyethylene terephthalate resin (hereinafter simply referred to as PET) and a multilayer direct blow resin container A multilayer resin container using a predetermined density polyethylene resin as the innermost resin (for example, see Patent Document 1), a container using an EVOH (ethylene-vinyl alcohol copolymer) resin, a PE (polyethylene) resin, A multilayer structure container using PP (polypropylene) resin or the like has been proposed.
JP-A-6-106606

  Among the above conventional techniques, the biaxial stretch blow molded PET container is excellent in the surface gloss of the container because of the PET resin, but in order to mold the container, a cold parison molding method is taken as an example. Each equipment of a heating machine and a biaxial stretch blow molding machine is required. In addition, it requires a mold for parison molding and a mold for biaxial stretch blow molding after heating, which increases equipment costs and mold costs. However, there was a disadvantage that it was limited.

In the case of a multi-layered container using glossy PET resin or EVOH resin as the outermost layer, PE resin is mostly used for the base resin layer inside the container. Peeling occurs due to lack of compatibility.
Therefore, it is necessary to interpose an adhesive layer between the PET resin or EVOH resin and the PE resin. However, the adhesive layer of these multilayer containers may be deteriorated or peeled off due to the contents, and there is a problem that the use is limited to an adhesive suitable for the contents.

  Further, even if the container body may be required to have transparency depending on the application, the transparency of the outermost PET resin or EVOH resin may be impaired due to the influence of the adhesive layer. Furthermore, in the case of conventional multi-layer resin containers, it is often the case that different resin configurations that do not melt even when heated are used, so it is possible to reuse molding waste generated during molding or molding defects in the product container during molding. For this reason, there is a problem that the utilization rate of the resin is reduced, the amount of waste is increased, and it may become a burden on the environment.

  In the case of PE resin, there is an outer layer of a high-density PE container having no gloss, which uses low-density PE that is glossy and excellent in transparency as compared with high-density PE. In addition, in the case of PP containers, since transparency is inferior, there are examples of using PP with excellent gloss and transparency as the outer layer. However, PE and PP resins have crystallinity, and transparency is affected by this. Since PP is originally inferior, copolymerizing groups that hinder crystallization, blending resin and chemical synthesis products, and using PP or PE with improved transparency is used for the outer layer. However, these are considerably inferior in transparency and texture compared to direct blow PET, and there are few practical examples in cosmetic containers and the like. In addition, PP and PE may permeate or adsorb cosmetic raw materials and fragrances, and may be restricted in use in cosmetic containers and the like.

  The present invention has been made in order to solve the various problems as described above, and has an excellent appearance as a cosmetic container and the like, and at the same time, molding waste and defective products generated during molding are regenerated in the molding process. An object of the present invention is to provide a multi-layer structure resin container that can be used or recycled by direct blow molding. In the case of the present invention, since the molding equipment cost and the mold cost are cheaper than those of the biaxial stretch blow molding, it is possible to cope with a large variety of small-quantity production.

  The structure of the present invention for achieving the above object will be described in detail. The invention according to claim 1 is an outermost layer forming the outer side of the container body in a container having a multilayer structure in which a thermoplastic synthetic resin is directly blow-molded. A multilayer structure resin characterized by using a transparent polyethylene terephthalate resin as a resin material and a polyethylene terephthalate resin that develops an alabaster color or ceramic color by blending a colorant in an inner layer in contact with the outermost layer. It is a container.

  The invention according to claim 2 uses a transparent polyethylene terephthalate resin as a resin material of the outermost layer forming the outer side of the container body in a multilayer structure container in which a thermoplastic synthetic resin is directly blow-molded, and in the outermost layer portion. A multilayer resin container characterized by using a polyethylene terephthalate resin that expresses pearly luster or glossy luster by blending a pearly luster or glittering colorant in an inner layer in contact therewith.

  The invention according to claim 3 uses a transparent polyethylene terephthalate resin as a resin material of the outermost layer forming the outer side of the container body in a multilayer structure container in which a thermoplastic synthetic resin is directly blow-molded, and in the outermost layer portion. A multilayer resin container characterized in that a polyethylene terephthalate resin made translucent or opaque by blending a colorant is used for the inner layer in contact therewith.

  The invention according to claim 4 uses a transparent polyethylene terephthalate resin as the outermost layer resin material forming the outside of the container main body and a pearly luster as the intermediate layer in a multilayer structure container in which a thermoplastic synthetic resin is directly blow molded. A three-layer structure using a polyethylene terephthalate resin that expresses pearly or glittering luster by blending a coloring agent or glittering colorant, and further using a polyethylene terephthalate resin colored by blending a coloring agent on the inner layer in contact with the intermediate layer It is the multilayer structure resin container characterized by becoming.

  Furthermore, the invention according to claim 5 is a multi-layered container in which a thermoplastic synthetic resin is directly blow-molded. In addition, a polyethylene terephthalate resin colored so as to be semitransparent in a desired color is used, and a polyethylene terephthalate resin colored in a desired color tone is used for the inner layer in contact with the outermost layer. This is a multilayer structure resin container.

  The PET resin in the present invention is a polyester resin that is generally used for direct blow molding, and is mainly intended for polyethylene terephthalate. Examples of terephthalic acid components include isophthalic acid, naphthalenedicarboxylic acid, and diphenyldicarboxylic acid. Acid, diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, aromatic dicarboxylic acid such as diphenylsulfone dicarboxylic acid, alicyclic dicarboxylic acid such as hexahydroterephthalic acid, hexahydroisophthalic acid, adipic acid, sebatin As part of other difunctional carboxylic acids such as acids, aliphatic dicarboxylic acids such as azelaic acid, oxyacids and / or ethylene glycol components such as trimethylene glycol, tetramethylene glycol, hexamethylene glycol Lumpur, decamethylene glycol, neopentyl glycol, diethylene glycol, other glycol component and one or more such functional compounds of these functional derivatives may be those obtained by copolymerizing such as triethylene glycol.

  As described above, any PET resin can be used as long as it is a grade for direct blow molding in the present invention. Conventionally used PET for biaxial stretch blow molding is a polyethylene terephthalate homopolymer, usually having a low IV value of 1 or less, and is not suitable for direct blow molding. PET for direct blow molding is a copolymer and has an IV value higher than that of a biaxially stretched grade so that it can be modified and direct blow molded. The direct blow molding PET has an IV value of 1.0 to 1.4, and usually around 1.2 is used because it is easy to mold.

  There is no restriction | limiting in particular in the coloring method of PET resin for direct blow molding used for this invention, You may use any coloring method conventionally known. For example, to obtain an alabaster color (snow flower plaster color) or ceramic color unique to glass bottles, 0.1% to 0.2% by weight of titanium white is added to 100% by weight of PET resin, and an accent is given to the product. Therefore, it can be colored in a desired color tone by blending a trace amount of ultramarine blue, carbon black, bengara and / or titanium yellow.

  In order to impart a pearly or glittering gloss that contributes to a high-grade appearance to the inner layer in contact with the outermost transparent PET resin that forms the outer side of the container body, 100% by weight of the PET resin has a mica-based interference. The pearl pigment is added in an amount of 0.2 to 2.0% by weight, and if necessary, an appropriate amount of a desired dye or pigment is added to develop a desired pearly luster or a multifaceted discolored glossy luster that changes slightly depending on the viewing angle. A PET resin container can be used.

  In addition, depending on the type of contents, the container body needs to be colored translucent or opaque. In that case, a transparent polyethylene terephthalate resin is used as the outermost resin material that forms the outside of the container body. The inner layer in contact with the outermost layer is made to exhibit a desired color tone using, for example, a colorant for PET resin, and as a whole, a PET resin container that is translucent or opaque can be obtained.

  The multi-layered resin container in the present invention is a direct blow molded container composed of two or more resin layers, and it is possible to obtain an appearance and characteristics that cannot be obtained with a single color material by multilayering. Between the outermost layer portion formed of a transparent polyethylene terephthalate resin and the innermost layer portion formed of a polyethylene terephthalate resin colored by blending the colorant, a pearlescent or glittering colorant is used as an intermediate layer. It is also possible to make a three-layer structure using a polyethylene terephthalate resin that can exhibit pearly luster or glossy luster by blending.

  In addition, the multilayer direct blow container in the present invention is made of a PET resin that can be multilayer direct blow molded, and is a multilayer direct blow container having two or more layers, and the outermost layer is based on a transparent PET resin. Can also be used a translucent polyethylene terephthalate resin tinted in frosted glass, white or other desired colors by blending colorants such as titanium white and inorganic matting agents.

  As described above, the multilayer structure resin container of the present invention uses a transparent polyethylene terephthalate resin or a translucent polyethylene terephthalate resin having a frosted appearance as the outermost resin material forming the outer side of the container body, and the outermost layer. Use polyethylene terephthalate resin that develops an alabaster or ceramic color or pearly or glittering luster for the inner layer in contact with the part. It is characterized by using an opaque polyethylene terephthalate resin, and the appearance is improved as a cosmetic container and the like, and each layer is made of the same polyester-based resin, which occurs during molding. Recycle or recycle molding waste and defective products in the molding process It is possible to reduce the burden on the environment, and the molding equipment cost and mold cost are cheaper than those of biaxial stretch blow molding. Is.

  Hereinafter, specific embodiments of the multilayer resin container of the present invention will be described in detail with reference to the accompanying drawings. 1 is a partial sectional view in the case of a two-layer structure, and FIG. 2 is a partial sectional view in the case of a three-layer structure.

  In any case, the container body 1 has a multilayer structure of two or more layers by direct blow molding of polyethylene terephthalate resin, and is basically transparent as a resin material of the outermost layer portion 2 that forms the outside of the container body 1. A polyethylene terephthalate resin is used (claims 1 to 4). However, in order to respond to various tastes or aesthetics of consumers, as a exception, white outer glass-like by mixing colorants such as titanium white and inorganic matting agent as the resin material of the outermost layer 2 or other A translucent polyethylene terephthalate resin colored in a desired color may be used (claim 5).

  The inner layer part 3 in contact with the outermost layer part 2 of the container main body 1 has an alabaster color or ceramic color by adding a colorant composed of titanium white, a trace amount of ultramarine blue, carbon black, bengara and / or titanium yellow. A polyethylene terephthalate resin that expresses pearly luster or luster luster by blending with the expressed polyethylene terephthalate resin or a pearlescent agent is used.

  In addition, depending on the type of contents, the container body needs to maintain a translucent or opaque state, and in that case, a transparent polyethylene terephthalate resin is used as the resin material of the outermost layer portion 2 of the container body, and The inner layer part 3 in contact with the outermost layer part 2 can be made into a PET resin container that exhibits a desired color tone by using, for example, a colorant for PET resin and becomes translucent or opaque as a whole.

  The container body 1 shown in FIG. 1 is a two-layer direct blow molded product, whereas the container body 1 shown in FIG. 2 has a three-layer structure, using a transparent or translucent polyethylene terephthalate resin. An intermediate layer 4 made of polyethylene terephthalate resin is interposed between the outermost layer portion 2 and the inner layer portion 3 that will be in direct contact with the contents. In this case, the inner layer part 3 can be colored transparent or colored opaque by blending the colorant. Further, the intermediate layer 4 expresses pearl luster, glitter such as gold or metal color, iris color, etc. by blending a pearlescent agent, a luster pigment, an iris pigment, and the like. As a result, a container with a beautiful and high-quality appearance can be obtained due to the coloring of the inner layer part 3. In addition, when coloring with these pigments to PET resin, the amount of blending is usually limited when using transparent dyes or using transparent pigments so as not to prevent the expression of these pigments. Needless to say. However, in the case of the multilayer structure container shown in FIG. 2, since the expression of these pigments is not hindered by the dyes and pigments, the use and blending amount of the transparent colorant are not restricted, so that wide coloration is possible.

A multi-layer direct blow container was prototyped and the appearance of the container was inspected and confirmed.
[Prototype container]
Capacity: 200ml
Sectional shape: elliptical height: 130 mm
Container structure: Outer layer 2 and inner layer 3 are made of transparent polyethylene terephthalate resin, and intermediate layer 4 is made of colored polyethylene terephthalate resin. PET: The outermost layer and innermost layer are directly blow molded. PET (Mitsubishi Rayon Dianite KC251) and the intermediate layer also use the direct blow molding PET (Mitsubishi Rayon Dianite KC251), and coloring shown in Examples 1 to 4 in Table 1 is performed. The appearance of the container was observed.
Comparative Example: As Comparative Examples 1 to 3, a container having a single layer structure in which a transparent resin layer was not used as the outermost layer was manufactured as a prototype.

  The containers of Examples 1 to 4 using a transparent polyethylene terephthalate resin for the outermost layer 2 are more transparent, translucent and opaque than the molded containers according to Comparative Examples 1 to 3 that do not have the transparent outer layer. Each of the containers showed a beautiful surface gloss and was confirmed to be a container exhibiting an excellent appearance with a high-class feeling while having a deep color to be emitted by the colored layer.

Crusher was used to crush the molding waste and defective molding generated during the alabaster color molding in Example 1 above, and 10%, 20%, and 30% were blended into the alabaster colored molding pellets of the intermediate layer, respectively. The appearance of the container was observed. As a result, the external appearance of the 10% and 20% blended products was as good as that of the standard color container. The 30% blended product had a slightly darker alabaster color, but when it was blended and molded into 10% alabaster colored pellets, it became the same color as the standard color.
For containers with pearl luster, molding wastes and defective moldings are crushed in the same way, and 10, 20 and 30% of these are mixed in pellets for the colored layer, and the same results are obtained. I was able to.

  When the Alabaster color prototype container of Example 1 was molded, the discharge amount of the outermost transparent PET resin was doubled, and the appearance of the prototype container with the transparent outer layer twice thick was observed. As a result, when the transparent outer layer was thickened compared to the container of Example 1, the depth of the prototype container was further increased, and the appearance with a high-class feeling was further improved. Similarly, the vermilion container of Example 4 was prototyped by doubling the discharge amount of the transparent outer layer, and compared with the container according to Example 4, the same result as above could be obtained.

In order to confirm the case where the outermost layer portion, the inner layer portion, and the intermediate layer have different grades of PET for direct blow molding, the following prototype experiment was conducted on an alabaster-colored container.
Mold of prototype container: same outer layer and inner layer of transparent PET as in Example 1: Kuraray KS710B-8
Grade of colored PET in the intermediate layer: Mitsubishi Rayon Dianite KC251
As a result of the trial production, the appearance of the container was the same as in Example 1, and no peeling of each resin layer was observed, and even in a drop test from a height of 50 cm to the iron plate, there was no damage and no peeling between the PET layers, confirming that there was no problem did.

Next, a transparent polyethylene terephthalate resin is used as the resin material of the outermost layer portion 2, and a polyethylene terephthalate resin that expresses pearly luster or iris luster by blending a pearlescent agent, a bright colorant and an iris pigment as the intermediate layer 4. And a direct blow container having a three-layer structure using polyethylene terephthalate resin colored by blending various colorants on the inner layer portion 3 in contact with the intermediate layer 4 (Examples 5 to 7), Table 2 shows the results of comparison with the direct blow containers according to Comparative Examples 4 to 6 that do not have a transparent outermost layer portion. The conditions of the direct blow prototype containers according to Examples 5 to 7 and Comparative Examples 4 to 6 are all the same as those of Examples 1 to 4.

  In the case of Example 5, the container body is excellent in surface gloss due to the presence of the inner layer part 3 made of polyethylene terephthalate resin blended with an opaque white titanium oxide pigment and colored in white opaque, and the depth of the gloss further increases. It retained a beautiful appearance suitable for cosmetic containers. In contrast, in the case of the prototype container according to Comparative Example 4, there is no outermost layer 2 made of transparent polyethylene terephthalate resin, so the surface is rougher than the prototype container of Example 5, and the appearance is clear without gloss. It was inferior.

  In both cases of Example 6 and Example 7, since the outermost layer of the container body is covered with the transparent polyethylene terephthalate resin, surface gloss is recognized, and a container having a deep appearance that changes to various colors depending on the viewing angle. Although obtained, in the case of Comparative Example 5 and Comparative Example 6, the surface was rough, there was no gloss, and the appearance was inferior.

  The pearlescent agents and glitter pigments are basically natural mica or synthetic silicon oxide flakes coated with titanium oxide. If necessary, the thickness of the coating can be changed or colored pigments or iron oxides can be used. It is coated and colored so that a pearly luster color, a gold color, and other various metal colors can be expressed. The iris color is also manifested by improving the smoothness of the surface of the natural mica and the synthesized silicon oxide flakes, and improving the thickness of the titanium oxide coating film and the smoothness of the coating film. Therefore, the pearlescent agent, the luster pigment, and the iris pigment can be said to be particulate pigments, which are pigments made of materials having substantially the same structure. Unlike normal dyes and pigments, these colorants composed of mica and silicon oxide flakes are coarse in the form of particles, so when blended in the raw material resin, the surface of the resin becomes rough. For this reason, a resin with particularly excellent surface gloss and transparency, such as polyethylene terephthalate resin, has a poor surface appearance due to the conspicuous surface roughness, and the compounding effect of these pigments is difficult to appear. This tendency is particularly strong when there are many pigment particles. For this reason, in the multilayer structure resin container according to the first to fourth aspects of the present invention, a transparent polyethylene terephthalate resin is basically used for the outermost layer portion of the container body.

Next, as the resin material of the outermost layer portion 2 forming the outer side of the container body, a polyethylene terephthalate resin colored so as to be translucent in a ground glass tone or white or other desired color tone by using a colorant is used. In addition, a direct blow container (Example 8 and Example 9) made using polyethylene terephthalate resin colored pale green or pink as the inner layer part 3 and a single-layer direct blow container made of polyethylene terephthalate resin colored pink ( Table 3 below shows the results of comparison between Comparative Example 7) and a single-layer direct blow container (Comparative Example 8) made of polyethylene terephthalate resin colored in a light green color. The conditions of the direct blow prototype containers according to Example 8, Example 9, Comparative Example 7, and Comparative Example 8 are all the same as those of Examples 1-4.

  In the case of Example 8, the outermost layer portion 2 is formed from a polyethylene terephthalate resin colored in a translucent white color by blending titanium oxide, and the polyethylene terephthalate resin colored pink as the inner layer portion 3 is used. Through the outermost PET resin colored white and translucent, the pink color of the inner layer can be seen through, the depth of pastel can be seen, and an appearance like a cosmetic container with an unprecedented luxury can be provided. . On the other hand, the single-layer container according to Comparative Example 7 did not leave the area of a conventionally known pink container.

  In addition, in the case of the resin container according to Example 9 in which an inorganic matting agent is added to polyethylene terephthalate resin and colored in frosted glass, the light green color of the inner layer portion 3 can be seen through the frosted glass, and the depth of pastel is observed. It was possible to obtain a blow container having an appearance like a cosmetic container with an unprecedented luxury. However, the single-layered container colored in the light green color according to Comparative Example 8 merely exhibited the appearance of a blow container colored in a normal light green color.

  As described above, the multilayer resin container of the present invention has at least two or more layers of direct direct blow molding using a transparent or semi-transparent PET resin on the outer layer and a transparent, translucent or opaque colored PET resin on the inner side in contact with the outer layer. A container having a beautiful appearance and a high-class feeling of deep colors can be provided by a synergistic effect of a multilayer structure.

  By direct blow molding of PET resin, the surface of the colored layer is covered with a transparent PET resin layer of the outer layer, and the glaze also looks like using a transparent glaze on ceramics, PET resin is equivalent or better than ceramics and glass containers Since it has transparency, it becomes a beautiful container with a high-quality appearance and excellent appearance. In addition, the multi-layered structure resin container according to the present invention is a multi-layer direct blow container made entirely of PET resin, so that resin molding waste and defective products generated during molding can be reused, improving the resin utilization rate. In addition, it is economically advantageous and the burden on the environment can be reduced.

  In addition, although PET has excellent transparency, there is a drawback that the resin is drawn down in a heated state, and there is a PET used for a colored layer even in the case of PET in which direct blow molding of a single layer container is difficult or impossible. Any PET suitable for direct blow molding can be used as an outer layer of multilayer direct blow molding to mold a multilayer resin container. Furthermore, although direct blow molding is possible, even in the case of a PET that cannot be put into practical use because the drop strength is inferior in a single layer container, the drop strength can be covered with the strength of the colored layer PET, so it is used as an outer layer. be able to.

It is a schematic sectional drawing which shows one Example of this invention multilayer structure resin container. It is a schematic sectional drawing which shows the other Example of this invention multilayer structure resin container.

Explanation of symbols

1: Container body 2: Outermost layer part 3: Inner layer part 4: Intermediate layer

Claims (5)

  In a container having a multilayer structure in which a thermoplastic synthetic resin is directly blow-molded, a transparent polyethylene terephthalate resin is used as an outermost layer resin material forming the outer side of the container body, and a colorant is applied to an inner layer in contact with the outermost layer portion. A multilayer resin container characterized by using a polyethylene terephthalate resin that develops an alabaster color or a ceramic color when blended.   In a container having a multilayer structure in which a thermoplastic synthetic resin is directly blow-molded, a transparent polyethylene terephthalate resin is used as the outermost layer resin material forming the outer side of the container body, and a pearlescent agent is used for the inner layer in contact with the outermost layer portion. A multilayer resin container characterized by using a polyethylene terephthalate resin that exhibits pearly luster or luster luster by blending luster coloring agents.   In a container having a multilayer structure in which a thermoplastic synthetic resin is directly blow-molded, a transparent polyethylene terephthalate resin is used as an outermost layer resin material forming the outer side of the container body, and a colorant is applied to an inner layer in contact with the outermost layer portion. A multi-layered resin container characterized by using a polyethylene terephthalate resin that has become translucent or opaque by blending.   In a multilayer container that directly blow-molds thermoplastic synthetic resin, a transparent polyethylene terephthalate resin is used as the outermost resin material that forms the outside of the container body, and a pearlescent or glittering colorant is added as an intermediate layer A polyethylene terephthalate resin that expresses pearly luster or glossy luster is used to form a three-layer structure using a polyethylene terephthalate resin colored by blending a colorant on the inner layer in contact with the intermediate layer. Multilayer resin container. In a container with a multilayer structure in which a thermoplastic synthetic resin is directly blow-molded, the outermost layer resin material forming the outside of the container body becomes a frosted glass tone or a semi-transparent shape in white or other desired color by blending a colorant. A multi-layered structure resin container characterized by using a polyethylene terephthalate resin colored in this way and using a polyethylene terephthalate resin colored in a desired color tones on the inner layer in contact with the outermost layer.

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