Container equipped with label and production method thereof

• US 5,223,315 A
• Filed: 12/06/1989
• Issued: 06/29/1993
• Est. Priority Date: 04/06/1988
• Status: Expired due to Term

• Current Assignee: TOYO Seikan Kaisha Limited (Toyo Seikan Group Holdings, Ltd.)
• Original Assignee: TOYO Seikan Kaisha Limited (Toyo Seikan Group Holdings, Ltd.)
• Inventors: Katsura, Tadahiko, Tanahashi, Toshifumi
• Primary Examiner(s): Robinson, Ellis P.
• Assistant Examiner(s): Nold, Charles R.
• Application Number:
  US07/445,661
• Time in Patent Office: 1,301 Days
• Field of Search: 428/35.7, 428/36.92, 428/447, 428/518, 428/34.9, 428/220, 428/349, 428/35.9, 428/35.8, 428/36.6, 428/36.92, 428/200, 428/204, 428/402, 264/34.7, 156/DIG. 5
• US Class Current: 428/36.92
• CPC Class Codes: B29C 2049/2412 outside the article
• CPC Class Codes: B29C 2049/2466 using electrostatic force
• CPC Class Codes: B29C 49/04 Extrusion blow-moulding
• CPC Class Codes: B29C 49/24 Lining or labelling
• CPC Class Codes: B29C 49/2408 In-mould lining or labelling
• CPC Class Codes: B65D 23/14 of tags , labels, cards, coupons, decorations or the like B65D23/008 takes precedence
• CPC Class Codes: G09F 3/04 to be fastened or secured by the material of the label itself, e.g. by thermo-adhesion by a separate adhesive layer G09F3/10
• CPC Class Codes: Y10T 428/1328 Shrinkable or shrunk [e.g., due to heat, solvent, volatile agent, restraint removal, etc.]
• CPC Class Codes: Y10T 428/1359 Three or more layers [continuous layer]
• CPC Class Codes: Y10T 428/1397 Single layer [continuous layer]
• CPC Class Codes: Y10T 428/24843 with heat sealable or heat releasable adhesive layer
• CPC Class Codes: Y10T 428/24876 Intermediate layer contains particulate material [e.g., pigment, etc.]
• CPC Class Codes: Y10T 428/2826 Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

In a hollow molded container equipped with a label and its production method, molding is made by use of a label consisting, as a base, of a stretched film of a plastic having a thermal shrinkage ratio greater than a mold shrinkage ratio of a plastic constituting the outer surface of a container, at a temperature 40° C. lower than the melting point or softening point of the plastic so that the label is bonded to the container at a residual equilibrium shrinkage ratio (Rs), defined below, of 0.5 to 100%: Rs=L₁ -L₂ /L₁, where L₁ is a length of a label film peeled from the container and L₂ is a length when the peeled label film is brought to equilibrium at the temperature (T₁) described above. In this manner, crease and swelling of the label during labelling operation inside the mold can be prevented and adhesion and peel-resistance between the label and the container outer surface can be improved.

Claims

1. A process for the preparation of a labelled hollow vessel having a non-bulging and non-wrinkling outer label surface with excellent adhesion and peeling resistance, which comprises

preparing a label composed mainly of a drawn film of a plastic material having a heat shrinkage factor measured in the machine direction larger than the forming shrinkage factor of a plastic material constituting the outer surface of a vessel wherein the heat shrinkage factor is measured at a temperature (T₁) lower by 40°

C. than the melting point or softening point of the plastic material constituting the outer surface of the vessel;

attaching the label to the inner surface of a cavity of a blow mold;

blow-forming a single-layer or multiple-layer plastic parison or sheet in the blow mold to bond the label to the surface of a side wall portion of the vessel formed, and

wherein the plastic material constituting the outer surface of the vessel is a polyolefin.

2. A process according to claim 1, wherein the residual equilibrium shrinkage factor (Rs), defined by the following formula, of the drawn plastic film is in the range of from 0.5 to 100%:

##EQU3## wherein L₁ is the length of the label film peeled from the vessel and L₂ is the length of said peeled label film equilibriated at a temperature (T₁) lower by 40°

C. than the melting point or softening point of the plastic material constituting the outer surface of the vessel.

3. A process according to claim 1, wherein the label is a laminate comprising

an outer layer of said drawn plastic film,

a print layer formed on the inner side of the film and

an inner layer of a hot-melt adhesive resin.

4. A process according to claim 1, wherein the resin constituting at least the outer surface of the vessel is an olefin resin and the drawn plastic film is a drawn olefin resin film.

5. A process according to claim 4, wherein the drawn plastic film is a drawn foamed olefin resin film.

6. A process according to claim 1, wherein the label is a laminate comprising

at least one layer of a drawn plastic film having a heat shrinkage factor larger than the forming shrinkage factor of the plastic material constituting the outer surface of the vessel at a temperature (T₁) lower by 30°

C. than the melting point or softening point of the plastic material constituting the outer surface of the vessel,

a thin layer of a metal having a thickness of 50 to 150,000 Å

and

a thermoplastic adhesive layer.

7. A process according to claim 6, wherein the laminate has a layer structure comprising an outer layer of a drawn plastic film, an intermediate layer of a metal foil and an inner layer of a thermoplastic adhesive.

8. A process according to claim 6, wherein the laminate has a layer structure comprising an outer layer of a drawn plastic film, an intermediate layer of a metal-vacuum-deposited drawn plastic film and an inner layer of a thermoplastic adhesive.

9. A process according to claim 1, wherein the process comprises

stacking many labels in a magazine,

sucking and delivering the labels into the mold one by one, and

attaching the delivered label to the surface of the mold.

10. A process according to claim 1, wherein the label comprises

a layer of said drawn plastic film,

a print layer formed on the inner face side of the film layer,

a hot-melt adhesive layer formed on the print layer and,

optionally, an overcoat layer formed on the outer surface side of the film layer, and

wherein resin beads, inorganic beads or a mixture of resin beads and inorganic beads having a particle size of 0.1 to 100 μ

m are present in any one of the print layer, the hot-melt adhesive layer and the overcoat layer and the center line average height as measured by JIS B-0601 in any of the surfaces of the label is 0.2 to 50 μ

m.

11. A process according to claim 1, wherein the label is a laminate comprising a substrate of said drawn plastic film and an adhesive layer of chlorinated polypropylene formed on one surface of the substrate.

12. A process according to claim 1, wherein the label is a heat-bondable film label comprising a layer of said drawn plastic film, a print layer formed on the inner surface side of the film layer, a hot-melt adhesive layer formed on the print layer and an overcoat layer composed of a release substance having a static friction coefficient smaller than 0.20.

13. A process according to claim 1, wherein the label is a laminate comprising a substrate of said drawn plastic film and an adhesive layer composed of a blend of chlorinated polypropylene and a copolymer of ethylene with a carbonyl group-containing ethylenic monomer, which is formed on one surface of the substrate.

14. A process according to claim 1, wherein the label is a laminate comprising a substrate of said drawn plastic film and an adhesive layer of a copolymer composed mainly of ethylene and containing an ethylenically unsaturated carboxylic acid or a derivative thereof as a comonomer, which is formed on one surface of the substrate.

15. A labelled vessel comprising

a plastic vessel formed by blow-molding and

a label bonded to the surface of a side wall portion of the vessel by an in-mold labelling operation, wherein the plastic material constituting the outer surface of the vessel is a polyolefin, and the label is a label comprising a drawn plastic film as the substrate and the label is bonded to the vessel so that the residual equilibrium shrinkage factor (Rs), defined by the following formula, of the drawn plastic film is from 0.5 to 100%:

##EQU4## wherein L₁ is the length of the label film peeled from the vessel and L₂ is the length of said peeled label film equilibrated at a temperature (T₁) lower by 40°

C. than the melting point or softening point of the plastic material constituting the outer surface of the vessel.

16. A labelled vessel as set forth in claim 15, wherein the resin constituting at least the outer surface of the vessel is an olefin resin and the drawn plastic film is a drawn olefin resin film.

17. A labelled vessel as set forth in claim 15, wherein the drawn plastic film is a drawn foamed olefin resin film.

18. A labelled vessel as set forth in claim 15, wherein the label is a laminate comprising an outer layer of said drawn plastic film, a print layer formed on the inner surface side of the film and an inner layer of a hot-melt adhesive.

19. A labelled vessel as set forth in claim 18, wherein the adhesive layer is chlorinated polypropylene.

20. A labelled vessel as set forth in claim 18, wherein the adhesive layer is a blend comprising chlorinated polypropylene and a copolymer of ethylene with a carbonyl group-containing ethylenic monomer.

21. A labelled vessel as set forth in claim 18, wherein the adhesive resin layer comprises an ethylenic copolymer composed mainly of ethylene and containing and ethylenically unsaturated carboxylic acid or a derivative thereof as a comonomer.

22. A labelled vessel as set forth in claim 15, wherein the label is a laminate comprising at least one layer of said drawn plastic film, a thin layer of a metal and a thermoplastic adhesive layer.

23. A labelled vessel as set forth in claim 15, wherein the label comprises

a layer of said drawn plastic film,

a print layer formed on the inner face side of the film layer,

a hot-melt adhesive layer formed on the print layer and,

optionally, an overcoat layer formed on the outer surface side of the film layer, and wherein resin beads, inorganic beads or a mixture of resin beads and inorganic beads having a particle size of 0.1 to 100 μ

m are incorporated in any one of the print layer, the hot-melt adhesive layer and the overcoat layer and the center line average height as measured by JIS B-0601 in any of the surfaces of the label is 0.2 to 50 μ

m.

24. A labelled vessel as set forth in claim 15, wherein the label is a heat-bondable film label comprising a layer of said drawn plastic film, a print layer formed on the inner surface side of the film layer, a hot-melt adhesive layer formed on the print layer and an overcoat layer composed of a release substance having a static friction coefficient smaller than 0.20.