JPH115275A - Multi-layer blow container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layer blow-molded container which has a frost (delustered) impression, and at the same time, has high class, secure, soft and warm feelings when being touched by hand, and also, is equipped with excellent functions such as being hard to slip at the time of usage. SOLUTION: This multi-layer blow container is a hollow container of multiple layers which is formed of at least an innermost layer and an outermost layer, and the innermost layer is formed of a crystalline polyolefin based resin, and the outermost layer is formed of an olefin based thermoplastic elastomer wherein the JIS-A hardness by JIS-K6 is 50-97, and the glossiness by JIS-Z8741 (an angle of incidence of 60 deg.) is 20% or lower, and which is partially crosslinked, and/or a styrene based thermoplastic elastomer wherein a hydrogenated derivative of a styrene.conjugate diene block copolymer with a numeral average molecular weight of 50,000-300,000, are blended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer blown container having a frost (matte) feeling. More specifically, it has a frost (matte) feeling found in glass cosmetic bottles and plastic shampoo containers, has a soft and warm feel when eaten by hands, and is non-slip and easy to use when used. The present invention relates to a multilayer blow container.

[0002]

2. Description of the Related Art Conventionally, glass bottles having a frosty feeling are:
It is widely used in the field of cosmetics and the like from the viewpoint of luxury and profound feeling, but has problems that it is heavy, expensive, and cracks occur when dropped. In order to improve this, in recent years, weight reduction, impact resistance improvement, and cost reduction by a blow-molded plastic container have been promoted. Therefore, as one method for giving a frosty feeling to a blow-molded plastic container, there is generally a method of roughening the cavity surface of a mold. Since it is difficult to sufficiently obtain the transfer of the plastic, there have been proposed methods of increasing the molecular weight of the plastic used or giving a frosty feeling to the surface of the plastic itself by copolymerization. However, such a blow-molded plastic container or a conventional glass bottle having a frosted feeling only has a luxurious feeling and a solid feeling just as it looks. On the other hand, a multilayer blow container made of a thermoplastic material is disclosed in
Japanese Unexamined Patent Publication No. 54-53088 discloses a method in which different resins are provided on a ring on the surface of a container, as described in JP-A-54-53088. Japanese Patent Application Laid-Open No. 4-175163
A frosted polypropylene having a specific MFR and a polypropylene having a specific MFR and an index of number average molecular weight / weight average molecular weight is known. On the other hand, a multilayer blow-molded product is disclosed in
42327, JP-A-63-115741, JP-A-Hei 2
Hard resin as described in each publication such as -78521 /
Soft resin or thermoplastic elastomer is known,
Both are merely related to automobile parts having a softened surface, not to containers.

[0003]

SUMMARY OF THE INVENTION Without impairing the basic quality of a blow-molded container, not only is the appearance luxurious and profound due to the mere frost feeling, but also the luxurious feeling and security when touched by hands. It is another object of the present invention to obtain a blow molded container having excellent functions in practical use.

[0004]

Means for Solving the Problems In view of such circumstances, the present inventors have made extensive efforts to form a surface layer of a specific olefin and / or styrene elastomer on the surface of a crystalline polyolefin resin. Not only does it look and feel profound, but also when you actually touch it,
They found that a multi-layer blown container with a function of ease of use, which is easy to use because it is easy to use because it is easy to fall because it is not only slipping and not cracking even in practical use, and it is hard to slip, led to the completion of the present invention. Things. That is, the multilayer blow container of the present invention is a multilayer hollow container formed of at least an innermost layer and an outermost layer, wherein the innermost layer is formed of a crystalline polyolefin-based resin, and the outermost layer is formed of JIS.
A partially crosslinked olefinic thermoplastic elastomer having a JIS-A hardness of 50 to 97 according to K6301 and a gloss of 20% or less according to JIS-Z8741 (incident angle of 60 degrees) and / or a number average molecular weight of 50; 000 ~
It is characterized by being formed from a styrene-based thermoplastic elastomer containing 300,000 hydrogenated derivatives of a styrene-conjugated diene block copolymer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

[I] Multi-layer blow container (1) Structure As shown in FIGS. 1 and 2, the multi-layer blow molded container 1 of the present invention blow-molds a parison having a multi-layer structure formed of at least the innermost layer 3 and the outermost layer 4. The molded container is generally a hollow container whose body portion 2 is swollen, and it is important to use a specific material for the layer structure in order to impart a frost (matte) feeling to the container.

(2) Innermost layer In the multilayer blow container of the present invention, the crystalline polyolefin resin used for forming the innermost layer may be a polypropylene homopolymer, polypropylene copolymer, high-density polyethylene, High-density polyethylene, low-density polyethylene, linear low-density polyethylene and the like can be used. These resins may be used alone or as a mixture of two or more. Among these crystalline polyolefin resins, the bending elastic modulus according to JIS-K7203 is 5,000 from the viewpoint of container shape stability and the like.
It is preferable to use a polypropylene homopolymer, a polypropylene copolymer, or a high-density polyethylene having a kg / cm ² or more, particularly 7,000 kg / cm ² or more. When a resin other than the crystalline polyolefin resin is used for the innermost layer,
A reduction in environmental stress cracking (ESCR) and a decrease in thermal adhesion strength with the outermost layer occur.

(3) Outermost layer In the multilayer blow container of the present invention, an olefin-based thermoplastic elastomer and / or a styrene-based thermoplastic elastomer having specific properties are used to form the outermost layer. Olefin thermoplastic elastomer and / or
Alternatively, if a resin other than the styrene-based thermoplastic elastomer resin is used, there is a drawback that the soft feeling is not obtained, the feel is deteriorated, and the slip becomes easy.

(A) Olefin-based thermoplastic elastomer The olefin-based thermoplastic elastomer is JI
The JIS-A hardness according to S-K6301 is 50 to 97, preferably 60 to 95, and the gloss according to JIS-Z8741 (incident angle 60 degrees) is 20% or less, preferably 10%.
% Or less, and an olefinic thermoplastic elastomer having a degree of crosslinking of preferably 10% or more is used. If the JIS-A hardness is less than the above range, it has slippery performance when touched by hand, but it is too soft or sticky, which impairs the sense of quality. Meanwhile, J
If the IS-A hardness exceeds the above range, when touched by hand, it has a hard and cold feel, and there is not much difference from the conventional polypropylene single-layer blow container in the point of slipperiness, and the luxury feeling functionality is impaired, Slippery. If the glossiness exceeds the above range, there is no frost feeling, and there is a drawback that stickiness is generated and stains easily occur. Further, if the olefin-based thermoplastic elastomer is not crosslinked, there is a drawback that blow moldability is poor and stickiness is produced.

Such an olefin-based thermoplastic elastomer is manufactured by a conventional method and has a Mooney viscosity of ML.
_{1 + 8} (120 ° C.) is generally 10 or more, preferably 30
The above ethylene and propylene and / or carbon number 4 to 10
(E.g., ethylene / propylene copolymer rubber (EPM) or the like), or ethylene and propylene and / or a carbon number of 4 to 10
(Specifically, ethylene-propylene-diene monomer copolymer rubber (EPDM), etc.) obtained by copolymerizing an α-olefin with a diene monomer such as ethylidene norbornene, dicyclopentadiene, etc. And the polyolefin resin (specifically, polypropylene or the like) used in the innermost layer.
80% by weight, preferably 20 to 60% by weight, and 1 to 50% by weight of a paraffinic oil used as needed, and a crosslinking agent (specifically, an organic peroxide,
Phenolic resin-based crosslinking agent, etc.) 0.01 to 2% by weight, preferably 0.1 to 1.0% by weight, a crosslinking aid (specifically,
Acrylic polyfunctional compounds such as phenylmaleimide, divinylbenzene, trimethylolpropane trimethacrylate, etc.) 0.01 to 2% by weight, preferably 0.1 to 2% by weight
One or more components selected from 1.0% by weight are added and mixed, and generally heat-treated dynamically at a temperature of 180 to 250 ° C.
That is, the degree of cross-linking obtained by melt-kneading is preferably 10% or more, particularly preferably 20 to 80%. Even if the rubber part is partially cross-linked, it is completely cross-linked. It may be.

(B) Styrene thermoplastic elastomer The styrene thermoplastic elastomer has a number average molecular weight of 50,000 to 300,000, preferably 1
It contains a hydrogenated derivative of a styrene / conjugated diene block copolymer of from 0.00000 to 250,000. If a styrene-based thermoplastic elastomer containing a hydrogenated derivative of a styrene / conjugated diene block copolymer having a number average molecular weight less than the above range is used, the gloss of the obtained multilayer blown container is too high. On the other hand, when a material exceeding the above range is used, the spreadability deteriorates, and there is a problem in the blow moldability. The styrene-based thermoplastic elastomer is a hydrogenated derivative 20 of a styrene / conjugated diene block copolymer.
To 60% by weight, 10 to 40% by weight of the polyolefin resin (specifically, polypropylene, polyethylene, etc.) and 20 parts of paraffinic oil described in the section of the innermost layer.
６０60% by weight.

Styrene / conjugated diene block copolymer
Hydrogenated Derivatives The hydrogenated derivatives of the styrene / conjugated diene block copolymer include styrene / butadiene block copolymer, styrene / isoprene block copolymer and styrene / butadiene / isoprene block copolymer completely or partially. Is a styrene / ethylene / butylene / styrene copolymer (SEB
S), styrene-ethylene-propylene-styrene copolymer (SEPS) and styrene-ethylene-butylene-
Ethylene / propylene / styrene copolymer (SEEP
S), wherein the hydrogenated block of conjugated diene has a 1,2-microstructure of less than 70%, preferably 5%.
It is preferable to use one having a hydrogenation rate of 95% or more, and preferably 99%, less than 0%. When the conjugated diene is a mixture of isoprene and butadiene, the weight ratio of the mixture (isoprene / butadiene) is 90/10 to 30/70,
Particularly preferred are those of 80/20 to 40/60.
The polystyrene content of the styrene / conjugated diene block copolymer is preferably from 5 to 50% by weight, particularly from 15 to 45% by weight.
% By weight is preferred.

Other Ingredients The innermost layer of the crystalline polyolefin resin and the outermost layer of the thermoplastic elastomer may include titanium oxide,
Inorganic fillers such as talc, calcium carbonate, calcined clay, mica, and glass fiber can be blended within a range that does not significantly impair the purpose of the present invention. Further, if necessary, various pigments, dispersants, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, antifogging agents, antibacterial agents, antistatic agents, and the like can be added.

(5) Layer Structure As the layer structure of the multilayer blow container of the present invention, the thermoplastic elastomer of the outermost layer is 3 to 50 parts of the entire multilayer blow container.
%, Preferably 5 to 30%, particularly preferably 10 to 20%
%, And the crystalline polyolefin resin in the innermost layer is 97 to 50%, preferably 95 to 70% of the whole multilayer blow container.
%, Particularly preferably 90 to 80%.

(6) Other Layers The layers other than the inner layer and the outer layer of the crystalline polyolefin resin have a plurality of structures, for example, a manufacturing cost of a multilayer blow container, without departing from the object of the present invention. From the viewpoint of reduction, a reproduction layer including an outer layer may be provided, or a gas barrier resin such as ethylene vinyl alcohol resin or nylon, or an adhesive resin layer for bonding the resin may be provided.

[II] Production of Multilayer Blow Container The multilayer blow container of the present invention can be produced by a known blow molding method or equipment by multilayer blow molding.
In general, a raw material resin or the like is heated and melted using an extruder-type multilayer hollow molding machine, a multilayer molten parison is extruded from a die, and then the parison is sandwiched between molds, and blow molding is performed by blowing air. be able to.

[0016]

The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited to these examples. Example 1 MFR (230 ° C.) as inner layer material of multilayer blow container
Using propylene / ethylene random copolymer having an ethylene content of 3.2% at 8 g / 10 min.
65 parts by weight of _{1 + 8} (120 ° C.) 62 ethylene-propylene-ethylidene norbornene copolymerized oil-extended rubber (EP98, manufactured by Nippon Synthetic Rubber Co., Ltd.) (including 25 parts by weight of paraffinic oil (PW380, manufactured by Idemitsu Kosan Co., Ltd.)) and polypropylene resin (Novatech MA4 manufactured by Nippon Polychem) 3
5 parts by weight, JIS-K6301 JIS-K6301 partially melt-kneaded at a temperature of 200 ° C. in the presence of 0.3 parts by weight of organic peroxide and 0.4 parts by weight of divinylbenzene
After using an olefin-based thermoplastic elastomer having an S-A hardness of 85 and plasticizing each raw material with an extruder,
By continuously merging at a temperature of 0 ° C. and extruding as a two-layer fused parison, followed by blow molding, the volume 2
A 50 cc blow molded container having the shape shown in FIG. 1 was obtained. The average thickness (body) of this blow molded container is 0.9 mm,
The inner layer was 0.8 mm and the outer layer was 0.1 mm. The body of the blow-molded container was cut out and measured at an incident angle of 60 degrees in accordance with JIS-Z8741. As a result, the gloss was 4.0%.
Met. The blow-molded container was actually touched and evaluated in a dry state and a wet state by five monitors, and the following results were obtained. Dry and frosty high-grade sensation Good for all 5 Good for 5 Good security for soft feeling Good for 5 Good for 5 Good for sliding resistance Good for 5 Good for 5

Example 2 A hydrogenated derivative of a styrene / butadiene block copolymer having a number average molecular weight of 200,000 as an outer layer material using the same propylene / ethylene random copolymer as in Example 1 as an inner layer material of a multilayer blow container. 45 parts by weight (Clayton G1651 manufactured by Shell Chemical Co., Ltd.), 35 parts by weight of paraffinic oil (PW90 manufactured by Idemitsu Kosan Co., Ltd.), and polypropylene resin (Novatech PPM manufactured by Nippon Polychem Co., Ltd.)
A2) J obtained by melting and kneading 20 parts by weight at a temperature of 200 ° C.
Using a styrene-based thermoplastic elastomer having a JIS-A hardness of 90 according to IS-K6301 and plasticizing each raw material with an extruder, continuously merging at a temperature of 190 ° C., and extruding as a two-layer molten parison. By blow molding in the same manner as in Example 1, a blow molded container having a capacity of 250 cc and having the shape shown in FIG. 1 was obtained. The average thickness (body portion) of this blow molded container is 0.9 mm, and the inner layer is 0.8 mm.
mm and the outer layer was 0.1 mm. The body of the blow-molded container was cut out and measured at an incident angle of 60 degrees according to JIS-Z8741. As a result, the gloss was 2.5%.
About this blow molded container, by five monitors,
When actually touched and evaluated in a dry state and in a state of being wet with water, the following results were obtained. Dry and frosty high-grade sensation Good for all 5 Good for 5 Good security for soft feeling Good for 5 Good for 5 Good for sliding resistance Good for 5 Good for 5

COMPARATIVE EXAMPLE 1 A propylene / ethylene block copolymer having an MFR (230 ° C.) of 1.2 g / 10 minutes and an ethylene content of 6.2% was used, and at a temperature of 190 ° C., a capacity 25 having the same shape as in Example 1 was used.
A single-layer blow molded container of 0CC was molded. The average thickness (body portion) of this single-layer blow molded container was 0.9 mm.
Cut out the body of this single-layer blow molded container, and follow JIS-Z
As a result of measuring at an incident angle of 60 degrees according to 8741, the glossiness was 5.5%. The single-layer blow-molded container was actually touched and evaluated by a monitor of five persons in a dry state and a wet state with water, and the following results were obtained. Dry frosty high-grade feeling Good for all 5 Good for 5 Good security for soft feeling 5 Good for 5 Good for 5 Good for slip resistance 5 Good for 5 Good for 5 Good

[0019]

The multilayer blow-molded container of the present invention as described above does not impair the basic quality as a blow-molded container, and is not only visually plump and luxurious due to the frost feeling but also touches the hands. It is very useful industrially because it has high-grade feeling at the time, a sense of security, and excellent functions in practical use.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a multilayer blow molded container according to an embodiment of the present invention.

FIG. 2 is an enlarged partial sectional view of a trunk portion of the multilayer blow-molded container of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-layer blow molded container 2 Body 3 Innermost layer 4 Outermost layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23/00 C08L 55/02 55/02 B65D 1/00 B // B29K 9:06 23:00 B29L 9:00 22:00

Claims (1)

[Claims] 1. A multilayer hollow container formed of at least an innermost layer and an outermost layer, wherein the innermost layer is formed of a crystalline polyolefin resin, and the outermost layer is JIS-K63.
JIS-A hardness of 50 to 97 according to JIS 01 and JIS
A partially crosslinked olefinic thermoplastic elastomer having a glossiness of -Z8741 (incident angle of 60 degrees) of 20% or less and / or a number average molecular weight of 50,000 to 300,
A multilayer blow container formed of a styrene-based thermoplastic elastomer containing a hydrogenated derivative of a styrene / conjugated diene block copolymer of 000.