Polymer barrier liminate tube for container

Abstract

It is related to a packaging tube in which a laminate body uses a multilayer barrier film having an ethylene copolymer and a vinyl alcohol (EVOH) layer, and this tube can be used for contents such as cosmetics, hair-dye products, toothpastes, pharmaceutical creams, and so on. It is to provide a bounce-back property, preservation of contents and a flavor barrier property to a tube by forming a tube body from a laminate comprising an inner layer of a polyolefin resin, an intermediate layer of a gas-barrier resin and an outer layer of a polyolefin resin.

Claims

1. A laminated tube comprising: (a) a body part comprising a laminate comprising: (i) an outer polyolefin layer comprising a multilayer film; (ii) an intermediate layer comprising a plurality of extruded polyolefin layers, a plurality of extruded adhesive layers, and an ethylene/vinyl alcohol copolymer (EVOH) layer, wherein the EVOH layer is an extruded core layer, sandwiched between two of the extruded adhesive layers, and wherein each layer of said two extruded adhesive layers is laminated with one of the plurality of extruded polyolefin layers; and (iii) an inner polyolefin layer comprising a multilayer film, and (b) a shoulder, adhered to said body part, which is formed from a layer of a melt-blended resin composition comprising (i) high density polyethylene (HDPE), (ii) linear low density polyethylene (LLDPE), and/or low density polyethylene (LDPE), wherein a compounding ratio by weight of the components b(i) and b(ii) is 60 to 95:40 to 50; wherein the outer polyolefin layer, the intermediate layer and the inner polyolefin layer of the body part are laminated by a co-extrusion lamination, wherein the body part comprising the laminate has a tendency to bounce back to its original shape when the body part is squeezed, the outer polyolefin layer having a thickness of 120-200 microns, the inner polyolefin layer having a thickness of 90-165 microns, each of the plurality of extruded polyolefin layers in the intermediate layer having a thickness of 20-30 microns, each of the extruded adhesive layers having a thickness of 10-20 microns and the EVOH layer having a thickness of 10-30 microns.

2. The laminated tube according to claim 1, wherein each of the outer and inner polyolefin layers is a co-extruded blown film selected from the group consisting of high density polyethylene (HDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and combinations thereof.

3. The laminated tube according to claim 1, wherein the extruded polyolefin is selected from the group consisting of linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and combinations thereof.

4. The laminated tube according claim 1, wherein the extruded polyolefin is polyethylene having a density of 0.90-0.92 g/cc.

5. The laminated tube according to claim 1, wherein the adhesive is an anhydride-modified low-density polyethylene resin containing anhydride.

6. The laminated tube according to claim 1, wherein the laminate has a total thickness of 300-460 microns.

Description

DETAILED DESCRIPTION

(1) This invention described herein relates to a polymer (EVOH) barrier laminate having various total thicknesses in the range of 300-460 microns used for making a laminated tube. In one aspect of the laminate according to this invention, an extruded core layer of EVOH is sandwiched between extruded adhesive layers and extruded polyethylene layers. Thereafter, outer and inner polyethylene films are laminated in order to obtain a laminate sheet as a separate layer.

(2) One embodiment of this invention is to provide a laminate comprising:

(3) A. an outer polyolefin layer;

(4) B. an intermediate layer comprising extruded polyolefin layers, adhesive layers, an ethylene/vinyl alcohol copolymer (EVOH) layer, wherein the EVOH layer is an extruded core layer, on both sides thereof, sandwiched between two layers of the extruded adhesive layers, and wherein each layer of said two layers of the extruded adhesive layers is laminated with one of the two extruded polyethylene layers; and

(5) C. an inner polyolefin layer, in which the outer polyolefin layer, the intermediate layer and the inner polyolefin layer are laminated by a co-extrusion lamination,

(6) wherein each of the outer and inner polyolefin layers is a co-extruded blown film selected from the group consisting of high density polyethylene (HDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and combinations thereof.

(7) preferably the outer or inner polyethylene film is a co-extrusion blown film with 1 to 3 layers or more, the outer and inner polyethylene layers preferably are flexible.

(8) Each of the outer and inner polyolefin layers may be a multilayer film having the same or different thickness, wherein the thicknesses of said polyolefin layers are in the range of 90-200 microns,

(9) preferably the outer polyolefin layer has a thickness in the range of 120-200 microns, and the inner polyolefin layer has a thickness in the range of 90-165 microns.

(10) The extruded polyolefin in B is selected from the group consisting of linear low density polyethylene (LLDPE), low density polyethylene (LDPE) and combinations thereof, the extruded polyethylene layers in B are preferably made from a polyethylene resin having a density of 0.90-0.92 g/cc, and the extruded polyethylene layers in B are more preferably made from a polyethylene resin having a density of 0.903-0.945 g/cc.

(11) Each of the extruded polyolefin layers in B may have a thickness between 20-40 microns, preferably 20-30 microns.

(12) The ethylene/vinyl alcohol copolymer (EVOH) has an ethylene content from 27 mole % to 48 mole %.

(13) The adhesive layer is an anhydride-modified low-density polyethylene resin containing anhydride.

(14) In this invention, the thicknesses of the EVOH layer, the adhesive layer, the extruded LLDPE layer and the PE film can be the same or different, for a good example, however the thicknesses of the EVOH layer and the adhesive layer are about 10-50 and 10-40 microns, respectively, preferably 10-30 and 10-20 microns, respectively. For the extruded LLDPE layer and the PE film, the thicknesses are about 20-40 and 90-200 microns, respectively.

(15) In one embodiment of this invention, it provides:

(16) i. a body part made from a laminate comprising

(17) A. an outer polyolefin layer,

(18) B. an intermediate layer comprising extruded polyolefin layers, adhesive layers, an ethylene/vinyl alcohol copolymer (EVOH) layer, wherein the EVOH layer is an extruded core layer sandwiched between the two extruded adhesive layers on both sides, and wherein said two extruded adhesive layers are laminated with the two extruded polyethylene layers, and

(19) C. an inner polyolefin layer; and

(20) ii. a shoulder of a laminated tube container formed from a layer of a melt-blended resin composition comprising (a) high density polyethylene (HDPE), (b) linear low density polyethylene (LLDPE), and/or low density polyethylene (LDPE), in which a compounding ratio by weight of the components (a) and (b) is 60 to 95:40 to 50.

(21) A head part of the tube can be formed by means of injection molding and in compression molding procedures.

(22) The following part explains this invention in details by way of examples, however this invention is not considered to be limited to these illustrative examples.

Example 1

KPL-PBL-01: Outer LLDPE Film 120/Extruded LLDPE Layer 27.5/Adhesive 10/EVOH 15/Adhesive 10/Extruded LLDPE Layer 27.5/Inner LLDPE Film 90

(23) The inner polyethylene film having a thickness of 90 microns is laminated to the outer polyethylene film having a thickness of 120 microns by using co-extrusion of hot-melted LLDPE, adhesive and an EVOH resin. During the co-extrusion lamination procedure, the formed 5-layer film is obtained with a structure of Extruded LLDPE Layer 27.5/Adhesive 10/EVOH 15/Adhesive 10/Extruded LLDPE Layer 27.5.

Example 2

KPL-PBL-02: Outer LLDPE Film 200/Extruded LLDPE Layer 27.5/Adhesive 10/EVOH 15/Adhesive 10/Extruded LLDPE Layer 27.5/Inner LLDPE Film 90

(24) The inner polyethylene film having a thickness of 90 microns is laminated to the outer polyethylene film having a thickness of 200 microns by using co-extrusion of hot-melted LLDPE, adhesive and an EVOH resin. During the co-extrusion lamination procedure, the formed 5-layer film is obtained with a structure of Extruded LLDPE Layer 27.5/Adhesive 10/EVOH 15/Adhesive 10/Extruded LLDPE Layer 27.5.

Example 3

KPL-PBL-03: Outer LLDPE Film200/Extruded LLDPE Layer 30/Adhesive 10/EVOH15/Adhesive 10/Extruded LLDPE Layer 30/Inner LLDPE Film 165

(25) The inner polyethylene film having a thickness of 165 microns is laminated to the outer polyethylene film having a thickness of 200 microns by using co-extrusion of hot-melted LLDPE, adhesive and an EVOH resin. During the co-extrusion lamination procedure, the formed 5-layer film is obtained with a structure of Extruded LLDPE Layer 30/Adhesive 10/EVOH 15/Adhesive 10/Extruded LLDPE Layer 30.

Comparative Example 1

Outer LLDPE Film 170/Adhesive 25/EVOH 27/Adhesive 23/Inner LLDPE Film 245

(26) A co-extrusion procedure for a 5-layered tube with a barrier layer and symmetric layer composition is used to produce a co-extruded tube with a structure of LLDPE 170/Adhesive 25/EVOH 27/Adhesive 23/LLDPE 245.

(27) The present invention also provides a manufacturing process of a laminated tube. Firstly, a 3-layered LLDPE film is produced by using a co-extruded blown film. The Outer and inner LLDPE films can be the same or different. Moreover, the outer film should maintain stiffness and heat sealing properties, whereas the inner film should provide a good heat-sealing property. Secondly, a 5-layered laminate is produced by using a co-extrusion lamination process. The inner polyethylene film is laminated to the outer polyethylene film by using a co-extrusion of hot-melted LLDPE, adhesive, and an EVOH resin. The manufacturing process in this invention uses general available machines such as a co-extruded blown film manufacturing line, a co-extrusion lamination line, a laminated tube forming line and a head-part manufacturing line.

(28) Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) are shown in Table 1. The OTR and WVTR were evaluated in accordance with ASTM D3985 and ASTM F1249, respectively.

(29) TABLE-US-00001 TABLE 1 OTR and WVTR of Laminates OTR at 23° C., 0% WVTR at 38° C., 90% Thickness RH RH Examples microns cc/m.sup.2 .Math. day g/m.sup.2 .Math. day KPL-PBL-01 300 1.680 0.768 KPL-PBL-02 380 0.979 0.548 KPL-PBL-03 460 0.453 0.478 Comparative 490 1.520 0.466 Example 1

(30) KPL-PBL-01, KPL-PBL-02 and KPL-PBL-03 are polymer barrier laminates of this invention. The oxygen gas transmission rate (OTR) and water vapor transmission rate (WVTR) of all laminate sheets are clearly shown in Table 1. KPL-PBL-02 exhibits the higher oxygen barrier property (the lower OTR value) than that of KPL-PBL-01 by 42%, because the total thickness of the laminate is increased from 300 to 380 microns. KPL-PBL-03 exhibits the higher oxygen barrier property (the lower OTR value) than that of KPL-PBL-02 by 54%, because the total thickness of the laminate is increased from 380 to 460 microns.

(31) In this invention, the variation of the outer and inner films is used to provide several total thicknesses in order to obtain stability of the tube with the tube diameter in the range from 13 to 50 mm. It seems that a slight increase of the thicknesses of the outer and inner films will enhance the OTR barrier property. However, the thickness of the EVOH in the laminate is not varied, because there is a small change in the OTR value when the thickness of the EVOH layer is changed from about 15 to 30 microns. The OTR value of KPL-PBL-03 is three times higher than that of the comparative example 1.