JPS5944255B2 - container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a synthetic resin container having a pearl-like luster, and more particularly to a container whose walls have a multilayer structure to improve decorativeness and hygiene.

Conventionally, difficult pigments such as lead phosphate, basic lead carbonate, and zinc phosphate were mixed in as burl materials to impart pearl-like luster to single-layer thermoplastic resin containers. Many pigments are toxic, so they cannot be used in foods, cosmetics, or other applications. In addition, when a single-layer wall is mixed with burl material, light is diffusely reflected by the burl material particles present on or near the surface of the container wall.
It had a whitish appearance, did not have a so-called deep pearlescent luster, and had the disadvantage of being somewhat unsatisfactory in terms of decoration. The present invention has been devised to solve the above-mentioned drawbacks, and specifically, it is a container that employs a multilayer wall of three or more layers.

That is, a modified polyolefin resin mixed with a predetermined amount of burl material that produces a pearl-like decorative effect is used as a decorative layer, and a colored layer made of colored polyolefin resin is provided in close contact with the inside of the decorative layer. A container characterized in that a coating layer made of a plastic resin is provided in close contact with the outside of the decorative layer, and the three-layer structure of the colored layer, decorative layer, and coating layer forms all or part of the container wall. It is. DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the container of the present invention will be further explained based on the drawings.

FIG. 1 shows an example of a tube container, and the container body 1 has a container wall having a three-layer structure of the above-mentioned colored layer 2, decoration layer 3, and coating layer 4. Regardless of this container, the container of the present invention is one in which a container body having multilayer walls is produced at once by means such as a blow molding method using a multilayer extrusion molded container body or a multilayer extrusion device. It is necessary that the bonding strength between each layer is high, and therefore a modified polyolefin resin is used for the decorative layer which is the intermediate layer of the container of the present invention. Modified polyolefins include modified polyolefins obtained by graft copolymerizing carboxylic acids, copolymers of ethylene or vinyl monomers and acrylic acid, copolymers of ethylene or vinyl monomers and vinyl esters, and polyolefins with a backbone of polyolefins. There are ionomer resins, polyolefin resins graft-copolymerized with amide or imide, ethylene monovinyl acetate copolymers, etc., but in the present invention, in addition to using the above resins alone, at least two of the above resins can be used as a mixture. It also includes mixtures of the above resins and ordinary polyolefins. The decorative layer is made of modified polyolefin resin as described above with pearl material of 0.2~
10%, particularly preferably 1 to 3%.

The pearl material referred to here is a certain type of inorganic pigment, and when mixed into a highly transparent resin, it gives the resin a pearl-like luster. Specifically, these include certain natural products, metal oxides, or metal salts, such as fish scale powder, mica, titanium pigments (titanium oxide, etc.), bismuth pigments (bismuth trichloride, etc.), and lead. Examples include salt, but there are many others. As a general rule, it is not necessary to add a coloring agent to the decorative layer, which is an intermediate layer, since this will impede the transmission of light. However, colorants (pigments or dyes) are sometimes added to the decorative layer to achieve a certain effect, that is, to achieve a pearl-like luster rich in color. In this case, it is best to use a transparent colorant that does not impede the transmission of light, and if an opaque colorant is unavoidably used, it should be kept within 3% of the total amount to maintain light transmission. . The colored layer, which is an inner layer to the above-mentioned decorative layer, generally contains an opaque pigment of 0.5 to 40%.
However, if the decorative layer is thick or contains a large amount of pearl material, it may be colored with a transparent colorant.
Furthermore, in addition to the coloring agent, a pearl material may be added to the colored layer. Finally, regarding the covering layer which is the outer layer for the decorative layer, this is a thermoplastic resin layer with good transparency, and by overcoating the surface of the decorative layer, This prevents the diffused reflection of light that tends to occur with other materials, and doubles the pearl-like luster of the decorative layer.

Since the covering layer needs to allow light to reach the decorative layer, it is not originally necessary to color it. However, coloring using a small amount of transparent colorant and coloring using a small amount of opaque colorant not exceeding 2% is acceptable because transparency can be maintained. Furthermore, in order to maintain the transparency of this coating layer, it is preferable not to increase the degree of crystallinity. Fortunately, since the coating layer is the outermost layer of the container wall, it can be easily cooled down quickly and thus crystallization can be suppressed. The resin constituting the coating layer is preferably a resin that can be bonded to the decorative layer with a certain degree of strength, has high transparency, and ideally has excellent gas barrier properties. This is because the polyolefin resin constituting the colored layer and decorative layer has good water vapor barrier properties but poor gas barrier properties, and to compensate for this, it is better to select a resin with high gas barrier properties. From that point of view, for example, polyamide resin, saponified ethylene monovinyl acetate copolymer,
Resins such as polyvinyl chloride resin and polyvinylidene chloride are
It is suitable as a resin constituting the coating layer, and can provide containers with excellent gas barrier properties. The present invention is as described above. According to the container of the present invention, since there is a transparent coating layer on the surface of the wall of the container, the pearl material scattered on the surface allows light to be absorbed, unlike a conventional pearlescent container. Diffuse reflection does not occur and the light reaches the decorative layer containing the pearl material, producing a pearl-like luster with depth and depth.

In addition, in the case of the present invention, since a colored layer is arranged on the back of the decorative layer, it absorbs light (mainly light that has passed through the decorative layer) other than light reflected by the decorative layer (light that produces a so-called pearl-like luster). As a result, only the pearl-like luster becomes the main ingredient, and in the case of the container of the present invention, the pearl-like luster is extremely emphasized. Furthermore, according to the container of the present invention, since the pearl material can be mixed only in the decorative layer, which is the intermediate layer, even if a toxic pearl material is used, there is a risk that the poisonous material will be leached from the container wall. Therefore, the use can be expanded to areas that could not be used conventionally due to the toxicity of the container and the contents.

In addition, since the container of the present invention has a multilayer structure, the combination of resins that make up each layer provides gas barrier properties to the container wall.
It can provide good physical properties such as water vapor permeability, mechanical strength, and surface abrasion resistance.

Additionally, in the container of the present invention, the coating layer and the decorative layer can be colored to the extent that transparency is not impaired, and in that case, a pearl-like luster rich in color can be obtained. , the decorativeness is improved. Finally, in the multilayer wall of the container of the present invention, modified polyolefin is arranged in the intermediate layer, and the inner and outer layers in contact with the inner layer and outer layer can increase the affinity with the intermediate layer, so that the bonding strength between each layer of the container body is The container has good strength and durability. Moreover, since each layer is made of thermoplastic resin, if a multilayer extrusion device that can be easily manufactured by a normal molding method, such as a multilayer extrusion molding method or a multilayer blow molding method, is used, the pearl material in the decorative layer can be They are arranged in the flow direction, which makes the pearl material more susceptible to multiple reflections and doubles its pearl-like luster. As described above, the present invention is extremely excellent.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the container of the present invention in the shape of a tube container. 1... Container body, 2... Colored layer, 3...
... Decorative layer, 4... Covering layer.

Claims (1)

[Claims] 1. A modified polyolefin resin mixed with a predetermined amount of a pearl material that produces a pearlescent decorative effect is used as a decorative layer, a colored layer made of a colored polyolefin resin is provided in close contact with the inside of the decorative layer, and a transparent A coating layer made of a thermoplastic resin with good properties is provided in close contact with the outside of the decorative layer, and the three-layer structure of the opaque layer, decorative layer, and coating layer is used as all or part of a multilayer wall. A container featuring: 2. The container according to claim 1, wherein the coating layer is colored by mixing a transparent colorant into the coating layer or by mixing an opaque colorant in a range of 2% or less. 3. Mix a transparent colorant with the pearl material in the decorative layer, or
Alternatively, an opaque coloring agent may be mixed in a range of 3% or less,
Claim 1 or 2 in which the decorative layer is colored
Containers listed in section. 4. The thermoplastic resin constituting the coating layer is selected from polyamide, saponified ethylene-vinyl acetate copolymer, vinyl chloride resin, and vinylidene chloride resin in claim 1, 2, or 4. Container described in item 3.