JP4572502B2 - Laminates and containers - Google Patents

Description

【００５５】
比較例１で作製した低密度ポリエチレン単層チューブ容器では、約２ケ月以内で内容物である染毛剤が黒変し、内容物保存性においても重量減少率５％と大きかった。また、比較例２で作製した多層チューブ容器においては、内容物保存性では満足できるものであるが、５ケ月保存で染毛剤の黒変が発生し、長期保存という観点からは満足できるものでなかった。
一方、実施例１、２及び３で作製したチューブ容器では、酸素バリアー性、内容物保存性において、満足できるものであった。
また、酸化性重合体である無水マレイン酸変性ポリブタジエンの配合量をエチレン−ビニルアルコール共重合体樹脂９９３重量部に対し７重量部としたものは、無水マレイン酸変性ポリブタジエンの占める面積率が低く、酸化性重合体を配合した効果が明確に表れず、比較例２と同様に５ケ月保存で染毛剤の黒変が発生した。
【図面の簡単な説明】
【図１】本発明の積層体の層構成の一例を示す断面図である。
【図２】本発明の容器の一例を示す正面図である。
【符号の説明】
１ 積層体
２ 外層
３，５，７ 接着剤
４ 第二の層
６ 第一の層
８ 内層
９ チューブ容器
１０ 容器本体
１１ 注出口
１２ 逆止弁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminate, and more specifically, a first layer containing an amorphous or low crystalline copolymer of an olefin and a cyclic olefin, and a second layer containing an oxygen-absorbing resin composition. It is related with the container which was equipped with the layer and was excellent in content preservation nature, such as a fragrance retention property and water retention.
[0002]
[Prior art]
Conventionally, as a container that stores contents that change in quality when exposed to air, it has excellent oxygen barrier properties, and after squeezing out the contents, keep the shape as it is (plastically deformed) and suck outside air into the container. For reasons such as not being present, metallic tubes such as aluminum, tin, and lead have been often used. However, the above metal tube containers may not be used due to corrosion or the like depending on the properties of the contents, and are gradually made mainly of plastics such as polyolefin resin from the viewpoint of disposal and cost after use. It is replacing tube containers.
[0003]
However, in the case of a plastic tube container, unlike the metal tube container described above, there is a problem that the contents are altered due to the invasion of oxygen from the outside of the container through the container wall and the escape of moisture and volatile components from the contents. There is.
[0004]
As a solution for the problem of such a plastic tube container, as a scent retention, water retention container, a first intermediate layer made of an amorphous or low crystalline copolymer of olefin and cyclic olefin, An aroma retaining multilayer container in which an oxygen barrier property second intermediate layer made of an ethylene-vinyl alcohol copolymer is laminated via an adhesive resin layer has been proposed (Japanese Patent Laid-Open No. 9-11416). .
[0005]
However, even in the multilayer container proposed in JP-A-9-11416, particularly in the case of contents sensitive to oxygen such as a hair dye, although satisfactory in terms of aroma retention and water retention, It is insufficient in terms of oxygen barrier properties, and storage of 5 to 6 months causes a problem that the content turns brown or black.
[0006]
[Problems to be solved by the invention]
When the contents are sensitive to the external environment, the container for storing the contents must have several important performances such as oxygen barrier properties, moisture resistance (water retention), and light shielding properties. Higher oxygen barrier properties are required for sensitive contents.
Then, the objective of this invention is providing the laminated body and container which were excellent in higher oxygen barrier property, water retention, and fragrance retention property.
[0007]
[Means for Solving the Problems]
The present invention has been proposed in order to achieve the above object, and is characterized by having the following configuration.
That is, according to the present invention, at least the first layer composed of an amorphous or low-crystalline copolymer of olefin and cyclic olefin, ethylene vinyl alcohol copolymer, nylon resin, and polyglycolic acid resin are selected. A second layer made of an oxygen-barrier thermoplastic resin having an oxygen permeability coefficient of 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg (37 ° C., 0% RH) or less ; It is a multilayer plastic container in which the positional relationship between the layer and the second layer is formed in the order of the outer layer, the second layer / first layer, or the first layer / second layer / first layer. And further containing an oxidizing polymer and a transition metal catalyst, the average dispersed particle size of the oxidizing polymer determined by the area method in the cross section in the thickness direction of the oxygen barrier resin layer is 1 μm or less, And said Provided is a multilayer plastic container for hair dye, wherein the area ratio occupied by dispersed particles in the cross section in the thickness direction of the oxygen barrier resin layer is 1% or more.
[0008]
According to the present invention, the second layer has an oxygen permeability coefficient of 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · selected from an ethylene vinyl alcohol copolymer, a nylon resin, and a polyglycolic acid resin. The oxygen barrier thermoplastic resin of cmHg (37 ° C., 0% RH) preferably contains 0.3 to 20.0% by weight of the oxidizing polymer and 100 to 1000 ppm of the transition metal catalyst.
[0009]
The oxidizing polymer is preferably a polyene polymer.
[0010]
Moreover, it is preferable that the oxidizing polymer is a resin modified with an acid or an acid anhydride.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
[Action]
In the laminate and container of the present invention, at least the first layer is made of an amorphous or low crystalline copolymer of olefin and cyclic olefin, and further contains a second oxidizing polymer and a transition metal catalyst. By comprising an oxygen-barrier thermoplastic resin, the water retention, aroma retention and storage stability of the higher contents are improved.
[0012]
[Inner and outer layers]
In the laminate and container of the present invention, it is preferable to select an olefin resin as the resin constituting the inner and outer layers, and among them, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), wire Polyethylene (PE) such as linear low density polyethylene (LLDPE) and linear ultra-low density polyethylene (LVLDPE), polypropylene (PP), ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene -Butene-1 copolymer, ethylene-propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer (EVA), ion-crosslinked olefin copolymer (ionomer), or a blend thereof.
[0013]
[First layer]
By providing at least one layer of an amorphous or low crystalline copolymer of olefin and cyclic olefin as the first layer, water retention can be improved. Ethylene is preferred as the olefin, but other α-carbons having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 3-methyl 1-pentene, 1-decene and the like. Olefin is used alone or in combination with ethylene.
[0014]
As the cyclic olefin, basically, an alicyclic hydrocarbon compound having an ethylenically unsaturated bond and a bicyclo ring, particularly bicyclo [2.2.1] hept-2-ene, tetracyclo [4,4,0 , 1 ^2,5 , 1 ^7,10 ] -3-dodecene and the like are suitable, and those described in JP-A-3-726, JP-A-2-19632 and the like can be used. An ethylene-cyclic olefin copolymer is particularly suitable, but the cyclic olefin content in the ethylene-cyclic olefin copolymer is preferably 10 to 50 mol%, particularly preferably 15 to 45 mol%. By providing a layer made of this ethylene-cyclic olefin copolymer, the water retention and aroma retention of the contents are remarkably improved.
[0015]
[Oxygen barrier thermoplastic resin]
As the second layer, the oxygen permeation coefficient is 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg (37 ° C., 0% RH) or less in terms of storage stability and flavor retention of the contents. In particular, it is preferable to provide an oxygen barrier thermoplastic resin layer of 4.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg or less.
[0016]
The most preferable example of such a thermoplastic resin is ethylene-vinyl alcohol having a vinyl alcohol unit content of 40 to 85 mol%, particularly 50 to 80 mol%, and a saponification degree of 96 or more, particularly 99% or more. Mention may be made of copolymers.
[0017]
Other oxygen barrier thermoplastic resins include nylon resins, especially nylon 6, nylon 8, nylon 11, nylon 12, nylon 6,6, nylon 6,10, nylon 10,6, nylon 6 / 6,6 co-weight Examples thereof include aliphatic nylon such as coalescence, partially aromatic nylon such as polymetaxylylene adipamide, and polyglycolic acid resin.
[0018]
[Oxygen absorbing resin]
In the present invention, a polyene polymer and a transition metal catalyst are blended as an oxidizing polymer in the second layer made of an oxygen-barrier thermoplastic resin.
The oxygen-absorbing resin, that is, the resin used as the oxidizing polymer is preferably a polyene polymer, and an oligomer or polymer containing units derived from a conjugated diene having 4 to 20 carbon atoms is preferably used. As these monomers, for example, conjugated dienes such as butadiene and isoprene are suitable.
[0019]
Specific examples of polyene polymers include polybutadiene, polyisoprene, butyl rubber, natural rubber, nitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, styrene-isoprene-styrene copolymer, and the like. It can mention, but it is not limited to these.
[0020]
The carbon-carbon double bond in the polyene polymer used in the present invention is not particularly limited, and may be present in the main chain in the form of a vinylene group or in the side chain in the form of a vinyl group. In short, anything that can be oxidized is acceptable, but those in the form of vinyl groups are preferred because of their high oxidation rates.
[0021]
The blending ratio of the polyene polymer to the oxygen barrier thermoplastic resin is preferably in the range of 1 to 20 parts by weight. If the polyene polymer is less than 1 part by weight, there is no effect of blending in terms of oxygen barrier properties, and if it is more than 20 parts by weight, there will be a problem in terms of workability and moldability.
The polyene polymer used in the present invention is preferably modified with a carboxylic acid group, a carboxylic anhydride group or the like. Examples of the monomer used to introduce these functional groups include ethylenically unsaturated monomers having the above functional groups.
[0023]
As these monomers, it is desirable to use unsaturated carboxylic acids or derivatives thereof, and specifically, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, etc. α, β-unsaturated carboxylic acid, unsaturated carboxylic acid such as bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydroanhydride Examples include α, β unsaturated carboxylic acid anhydrides such as phthalic acid, and unsaturated carboxylic acid anhydrides such as bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid anhydride.
[0024]
The acid modification of the polyene polymer is produced by graft copolymerizing an unsaturated carboxylic acid or a derivative thereof by a method known per se.
[0025]
The polyene polymer particularly suitable for the purpose of the present invention preferably contains an unsaturated carboxylic acid or a derivative thereof in an amount such that the acid value is 5 KOHmg / g or more.
When the content of the unsaturated carboxylic acid or its derivative is within the above range, the acid-modified polyene polymer is well dispersed in the oxygen-barrier thermoplastic resin and oxygen is smoothly absorbed.
[0026]
The polyene polymer used in the present invention is preferably a liquid resin in a state modified with an acid or an acid anhydride from the viewpoint of dispersibility with respect to the oxygen-barrier thermoplastic resin.
[0027]
[Transition metal catalyst]
As the transition metal catalyst used in the present invention, iron, cobalt, nickel and the like are preferable, but other metal components such as copper, silver, tin, titanium, zirconium, vanadium, chromium and manganese can be exemplified. Among these metal components, the cobalt component has a high oxygen absorption rate and is particularly suitable for the purpose of the present invention.
[0028]
Transition metal catalysts are generally used in the form of inorganic or organic acid salts of the above transition metals.
Examples of inorganic acid salts include halides such as chlorides, sulfur oxyacid salts such as sulfates, nitrogen oxyacid salts such as nitrates, phosphorus oxyacid salts such as phosphates, and silicates.
On the other hand, examples of the organic acid salt include a carboxylate, a sulfonate, and a phosphonate. The carboxylate is suitable for the purpose of the present invention, and specific examples thereof include acetic acid, propionic acid, isopropylate. On acid, butanoic acid, isobutanoic acid, pentanoic acid, isopentanoic acid, hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid 2-ethylhexanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, decanoic acid, neodecanoic acid , Undecanoic acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, lindelic acid, tuzuic acid, petroceric acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, formic acid, chuic acid , Transition metal salts such as sulfamic acid and naphthenic acid.
[0029]
[Second layer]
According to the present invention, the second layer comprises an oxygen-barrier thermoplastic resin containing a polyene polymer as an oxidizing polymer and a transition metal catalyst. In particular, since the oxygen barrier thermoplastic resin exists as a continuous phase (matrix) and the oxidizable polymer exists as a dispersed phase, the surface area of the oxidizable polymer that is the dispersed phase increases, and oxygen absorption is increased. Done efficiently. At the same time, even when oxidation of the dispersed phase proceeds, excellent oxygen barrier properties and mechanical strength are maintained by the oxygen barrier thermoplastic resin remaining as a continuous layer.
[0030]
In the present invention, in the cross section in the thickness direction of the oxygen-barrier thermoplastic resin layer, the area-average average particle diameter of the oxygen-absorbing resin is 1 μm or less, and the cross-section in the thickness direction of the oxygen-barrier thermoplastic resin layer It is preferable in terms of oxygen absorption that the area ratio occupied by the dispersed particles in the mixture is 1% or more, and a multilayer container provided with the oxygen barrier thermoplastic resin layer having the above dispersion and distribution structure Has good moldability, and the structure and appearance of the structure to be formed are uniform, the thickness is uniform, and the smoothness is excellent.
[0031]
The area method average dispersed particle diameter can be determined by the following method.
A multilayer structure cut out from a multilayer plastic container is embedded in an epoxy / amine-based embedding resin for an electron microscope, the embedding resin is cured, and only the oxygen-absorbing resin is selectively stained for the cross section of the second layer. By using a dye that can be used, the oxygen-absorbing resin contained as the dispersed phase can be dyed.
Take a scanning electron microscope (SEM) photograph of the cross section of the dyed second layer, capture the image of this SEM photograph with a scanner, and use the image processing software on the computer screen to display the oxygen-absorbing resin and other parts. And the area S of the oxygen-absorbing resin dispersed particles existing in the predetermined area S ₀ and the number n of dispersed particles are measured. In order to improve accuracy, this operation is performed for a plurality of visual fields, ΣS and Σn are calculated from S and n obtained for each visual field, and an area method average dispersed particle diameter d is obtained from the following equation (1).
d = (ΣS / Σn) ^1/2 (1)
For a plurality of fields of view, the area ratio α occupied by the dispersed particles is determined from the calculated S ₀ and S according to the following formula (2).
α = 100 × ΣS / ΣS ₀ (2)
[0032]
Further, the transition metal catalyst contained in the second layer may be contained in an amount of 100 to 1000 ppm, particularly 200 ppm to 500 ppm as a transition metal amount with respect to the oxygen barrier thermoplastic resin and the oxidizing polymer. preferable.
[0033]
When the amount of the transition metal catalyst is below the above range, the oxygen barrier property tends to be insufficient. On the other hand, when the amount of the transition metal catalyst is less than the above range, the oxygen barrier property tends to decrease. On the other hand, when the amount exceeds the above range, the deterioration tendency at the time of kneading molding of the resin composition increases, which is not preferable.
[0034]
Various means can be used for blending the transition metal catalyst and the oxidizing polymer with the oxygen-barrier thermoplastic resin. Moreover, there is no special order in this combination, and blending may be performed in an arbitrary order.
[0035]
However, in blending the above components, it is necessary to uniformly blend while preventing wasteful oxygen absorption before use as much as possible. Here, the transition metal catalyst is a small amount compared to the oxygen barrier thermoplastic resin, and in order to perform uniform blending, generally, after the transition metal catalyst is dissolved in an organic solvent, this solution and the powder or granular oxygen barrier heat It is preferable to mix with a plastic resin and, if necessary, dry the mixture under an inert atmosphere.
[0036]
On the other hand, the blending of the oxidizable polymer to the oxygen barrier thermoplastic resin carrying the transition metal catalyst is good, so that side reactions and pre-reactions between the transition metal catalyst and the oxidizable polymer can be performed. Can be prevented.
[0037]
Solvents for dissolving the transition metal catalyst include alcohol solvents such as methanol, ethanol and butanol, ether solvents such as dimethyl ether, diethyl ether, methyl ethyl ether, tetrahydrofuran and dioxane, ketone solvents such as methyl ethyl ketone and cyclohexanone, n- Hydrocarbon solvents such as hexane and cyclohexane can be used, and it is generally preferable to use such a concentration that the transition metal catalyst concentration is 5 to 90% by weight.
[0038]
The mixing of the oxygen-barrier thermoplastic resin, the oxidizing polymer, and the transition metal catalyst, and subsequent storage is preferably performed in a non-oxidizing atmosphere so that oxidation in the previous stage of the composition does not occur. For this purpose, mixing or drying under reduced pressure or in a nitrogen stream is preferred. This mixing and / or drying can be performed before the molding process using an extruder or an injection machine with a vent type or a dryer.
[0039]
In the most preferred embodiment of the present invention, an oxygen-barrier thermoplastic resin coated with a transition metal catalyst is previously melt-kneaded using a twin-screw extruder equipped with a side feed, and an oxidizing polymer is added to the melt-kneaded product. Supply in liquid form to achieve uniform kneading of both.
In the kneading method using the above twin screw extruder, kneading can be performed at a low temperature and pressure, and a uniform kneaded product can be obtained while preventing generation of gels and the like.
[0040]
The second layer of the present invention includes a filler, a colorant, a heat stabilizer, a weather stabilizer, an antioxidant, an antioxidant, a light stabilizer, an ultraviolet absorber, an antistatic agent, a metal soap, a wax and the like. A known resin compounding agent such as a lubricant, a modifying resin or rubber can be blended according to a formulation known per se.
For example, by incorporating a lubricant, the bite of the resin into the screw is improved. Lubricants include metal soaps such as magnesium stearate and calcium stearate, hydrocarbons such as fluid, natural or synthetic paraffin, microwax, polyethylene wax, chlorinated polyethylene wax, and fatty acid such as stearic acid and lauric acid. , Stearic acid amide, valmitic acid amide, oleic acid amide, esylic acid amide, fatty acid monoamide type or bisamide type such as ethylene bisstearamide, butyl stearate, hydrogenated castor oil, ethylene glycol An ester type such as monostearate, an alcohol type such as cetyl alcohol and stearyl alcohol, and a mixed system thereof are generally used. The amount of lubricant added is suitably in the range of 50 to 1000 ppm on a thermoplastic basis.
[0041]
[container]
Next, the laminated structure of the container made of the laminate of the present invention is exemplified by representing the second layer as OBR, but is not limited thereto.
Example of layer structure: From the outer layer (1) PE / AD / OBR / AD / COC / AD / PE
(2) PE / AD / COC / AD / OBR / AD / COC / AD / PE
(3) PP / AD / OBR / AD / COC / AD / PP + REG / PP
(4) PET / AD / OBR / AD / COC / AD / PET
Etc. can be illustrated. In the diagram, PE is polyethylene, PP is a polypropylene resin, COC is a copolymer of olefin and cyclic olefin, PET is polyethylene terephthalate, and AD is an adhesive resin. REG is a recovered resin. What is connected with + like PP + REG is a mixture.
[0042]
In the container of the present invention, the thickness of the second layer is not particularly limited, but is generally in the range of 3 to 100 μm, particularly 5 to 70 μm. That is, when the thickness of the second layer is thinner than the above range, the oxygen barrier performance is inferior, and even if it is thicker than the above range, there is no particular advantage in terms of the oxygen barrier performance, and the amount of resin increases. And disadvantageous in terms of container properties such as a decrease in flexibility and flexibility of the material.
[0043]
Further, the thickness of the layer made of a copolymer of olefin and cyclic olefin is not particularly limited, but is generally 3 to 100 μm, particularly preferably 5 to 50 μm. If the thickness of the first layer is less than the above range, the oxygen barrier property of the second layer is reduced, and if it is thicker than the above range, cracking occurs at the time of buckling or a decrease in mechanical strength is caused.
[0044]
The container made of the laminate of the present invention can take the form of a cup-shaped, tray-shaped container, bottle, or tube container.
The bottle or tube is extruded from the parison, then pinched off the parison with a pair of split molds, and the direct blow molding that blows fluid into the inside of the bottle or tube. Also, the preform is injection molded, the preform is cooled, and then heated to the stretching temperature. In addition, the film is stretched in the axial direction and molded by biaxial stretch blow molding in which the fluid pressure blows in the circumferential direction. The cup or tray-like container is formed by means such as vacuum forming, pressure forming, bulging forming, plug assist forming, etc., for a film or sheet.
[0045]
For the production of the multilayer molded body, a coextrusion molding method known per se can be used.
[0046]
Further, the container of the present invention is suitably used as a tube container for storing cream or paste-like toothpaste, cosmetics, hair dyes, various pharmaceuticals, etc., and in particular, reacts with oxygen in the air and changes its color. When storing the hair dye, it is preferable to arrange a known check valve at the spout of the tube container in order to prevent the inflow of air into the container.
[0047]
【Example】
The invention is further illustrated by the following examples, but the invention is not limited to these examples.
[0048]
Example 1
Ethylene-vinyl alcohol copolymer resin pellets (EP-F101B: Kuraray Co., Ltd.) and cobalt neodecanoate with a cobalt content of 14% by weight (DICANTATE 5000: Dainippon Ink & Chemicals, Inc.) are mixed with a tumbler, and the amount of cobalt is mixed. 350 ppm of cobalt neodecanoate was uniformly attached to the surface of the ethylene-vinyl alcohol copolymer resin pellets. Next, using a twin screw extruder (TEM-35B: Toshiba Machine Co., Ltd.) equipped with a strand die at the outlet portion, a maleic anhydride modified liquid is drawn by a liquid feeder while pulling a low vacuum vent at a screw rotation speed of 100 rpm. Polybutadiene (M-2000-20: Nippon Petrochemical Co., Ltd.) was dropped to 50 parts by weight with respect to 950 parts by weight of the ethylene-vinyl alcohol copolymer resin to which cobalt was adhered, and the molding temperature was 200 ° C. Strands were drawn to produce pellets. The blending amount of maleic anhydride-modified polybutadiene in the pellets was 5% by weight. This pellet was used as a resin composition constituting the second layer (hereinafter abbreviated as OBR-1).
As the resin constituting the first intermediate layer, an appel made by Mitsui Chemicals, which is an olefin and a cyclic olefin copolymer (hereinafter abbreviated as COC), was used.
Using these resins, from the outside, as shown in FIG. 1, low density polyethylene / adhesive / OBR-1 / adhesive / COC / adhesive / low density polyethylene is formed by four extruders and a multilayer die. Four types and seven layers of parison were extruded, and a tube container having an internal volume of 200 mL and a total wall thickness of 450 μm was produced by a direct blow molding method.
As a result of measuring the dispersion state of the maleic anhydride-modified polybutadiene in the cross section in the thickness direction of the second layer according to the above formula (1) and formula (2) for the laminate obtained by cutting out from the tube container main body, area average particles The diameter was 0.30 μm, and the area ratio occupied by the dispersed particles was 4.5%.
[0049]
(Example 2)
In Example 1, among the resin compositions constituting the second intermediate layer, a resin composition (OBR-2) using polyglycolic acid instead of an ethylene-vinyl alcohol copolymer as an oxygen-barrier thermoplastic resin. A tube container similar to that of Example 1 was prepared except that the above was changed. As a result of measuring the area average particle diameter and the area ratio occupied by the dispersed particles from this tube container in the same manner as in Example 1, they were 0.29 μm and 4.3%, respectively.
[0050]
(Comparative Example 1)
A single-layer tube container made of low-density polyethylene having an internal volume of 200 mL and a total wall thickness of 450 μm was produced by direct blow molding.
[0051]
(Comparative Example 2)
By direct blow molding, from the outside, low density polyethylene / adhesive / ethylene-vinyl alcohol copolymer resin / adhesive / COC / adhesive / low density polyethylene, 4 types and 7 layers, internal volume 200 mL, total wall thickness A 450 μm tube container was prepared.
[0052]
(Comparative Example 3)
A tube container similar to that in Example 1 was prepared, except that maleic anhydride-modified polybutadiene was blended to 7 parts by weight with respect to 993 parts by weight of the ethylene-vinyl alcohol copolymer resin. As in Example 1, the area average particle diameter and the area ratio occupied by the dispersed particles were measured and found to be 0.28 μm and 0.6%, respectively.
[0053]
With respect to the tube containers prepared in Examples 1 to 3 and Comparative Examples 1 to 3, the oxygen barrier property and the content preservation were evaluated by the following methods. The results are shown in Table 1.
(Oxygen barrier properties)
A check valve is placed at the mouth of the tube container, and 140 ml of hair dye solution is filled from the open bottom under an oxygen concentration of 0.2% or less, and the bottom is sealed and shown in FIG. It was set as such a tube container. The tube container was stored for 10 months in an atmosphere of 45 ° C./80% RH, and the color change of the hair dye solution was visually observed. The standard for visual observation was that the contents turned black in less than 4 months, x that turned black in 4 months or more and 7 months or less, and ◯ that no discoloration was confirmed after storage for 7 months or more.
(Content preservation)
A check valve is arranged at the mouth of the tube container, and 140 ml of hair dye solution is filled from the opened bottom under a condition of oxygen concentration of 0.2% or less, and the bottom is hermetically sealed and shown in FIG. It was set as such a tube container. This sample was precisely weighed with a precision top balance. Next, it was stored for 6 months in an atmosphere of 45 ° C./80% RH, and the weight reduction rate of the contents after storage was determined. In this case, the weight loss rate after storage for 6 months was less than 3%, and the one with 3% or more was rated as x.
[0054]
[Table 1]

[0055]
In the low-density polyethylene single-layer tube container produced in Comparative Example 1, the hair dye as the content turned black within about 2 months, and the weight reduction rate was as large as 5% in content preservation. In addition, the multilayer tube container produced in Comparative Example 2 is satisfactory in the storage stability of the contents, but it is satisfactory from the viewpoint of long-term storage because the hair dye will turn black when stored for 5 months. There wasn't.
On the other hand, the tube containers prepared in Examples 1, 2, and 3 were satisfactory in oxygen barrier properties and content preservation properties.
In addition, when the blending amount of maleic anhydride-modified polybutadiene which is an oxidizing polymer is 7 parts by weight with respect to 993 parts by weight of ethylene-vinyl alcohol copolymer resin, the area ratio occupied by maleic anhydride-modified polybutadiene is low, The effect of blending the oxidizing polymer was not clearly shown, and the blackening of the hair dye occurred after 5 months storage as in Comparative Example 2.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a layer structure of a laminate according to the present invention.
FIG. 2 is a front view showing an example of the container of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Laminated body 2 Outer layer 3, 5, 7 Adhesive 4 Second layer 6 First layer 8 Inner layer 9 Tube container 10 Container main body 11 Outlet 12 Check valve

Claims (6)

At least a first layer composed of an amorphous or low crystalline copolymer of olefin and cyclic olefin, and an oxygen permeability coefficient of 5.5 × selected from ethylene vinyl alcohol copolymer, nylon resin, and polyglycolic acid resin. 10 ⁻¹² cc · cm / cm ² · sec · cm Hg (37 ° C., 0% RH) or less of a second layer made of an oxygen-barrier thermoplastic resin , the positions of the first layer and the second layer A multilayer plastic container in which the relationship is formed from the outer layer, the second layer / first layer, or the first layer / second layer / first layer in this order , further comprising an oxidizable polymer and While containing a transition metal catalyst, the average dispersed particle diameter of the oxidizing polymer determined by the area method in the cross section in the thickness direction of the oxygen barrier resin layer is 1 μm or less, and the oxygen barrier resin layer thickness A multilayer plastic container for a hair dye, wherein the area ratio occupied by dispersed particles in a directional cross section is 1% or more. The second layer, the oxygen barrier thermoplastic resin, the oxidizable polymer is 0.3 to 20.0 wt%, and, according to claim 1, wherein the transition metal catalyst contains 100ppm to 1000ppm A multilayer plastic container for hair dyes as described in 1.   The multilayer plastic container for hair dye according to any one of claims 1 to 2, wherein the oxidizing polymer is a polyene polymer.   The multilayer plastic container for a hair dye according to any one of claims 1 to 3, wherein the oxidizing polymer is a resin modified with an acid or an acid anhydride.   The multilayer plastic container for hair dye according to claim 4, wherein the inner layer and the outer layer of the container are made of low density polyethylene.   The multilayer plastic container for a hair dye according to claim 4 or 5, wherein the container is a tube container comprising a container main body and a spout, and the spout is provided with a check valve.

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