Hot-melt adhesive and use thereof

Abstract

The present invention relates to the use of a hot-melt adhesive for adhesive bonding of at least a first packaging and a second packaging, the hot-melt adhesive comprising: (a) 7-48 parts per weight of a polymer component, the polymer component comprising a styrene block copolymer; (b) 15-52 parts per weight of a tackifying component, wherein the tackifying component comprises thermoplastic adhesive resin, aliphatic hydrocarbon, cycloaliphatic hydrocarbon, aromatic hydrocarbon, the respective hydrocarbon optionally being modified and/or hydrogenated, terpenes, the terpenes optionally being modified or hydrogenated, rosins, the rosins optionally being modified or hydrogenated, or mixtures thereof; (c) 5-25 parts per weight of a plasticizer component, wherein the plasticizer component comprises paraffinic oils, naphthenic oils, polybuten, polybutadien, dibasic esters, polyols or mixtures thereof; and d) 0.02-1.2 parts per weight of a stabilizer component, wherein the stabilizer component is a light stabilizer, preferably as a sterically hindered phenolic antioxidant and/or a sterically hindered amine, most preferably is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

Claims

1. A pack comprising a first packaging connected to a second packaging by a hot-melt adhesive by adhesive bonding, the adhesive bonding being made by the hot-melt adhesive, and the hot-melt adhesive comprising: (a) 30 to 45 parts per weight of a polymer component, the polymer component comprising a styrene block copolymer, wherein the styrene block copolymer is selected from the group consisting of polystyrene-block-poly(ethylene-RAN-butylene)-block-polystyrene and a mixture of styrene-isoprene-styrene block copolymer and styrene-butylene-styrene block copolymer; (b) 30 to 50 parts per weight of a tackifying component, wherein the tackifying component comprises thermoplastic adhesive resin, aliphatic hydrocarbon, cycloaliphatic hydrocarbon, aromatic hydrocarbon, the respective hydrocarbon optionally being modified and/or hydrogenated, terpenes, the terpenes optionally being modified or hydrogenated, rosins, the rosins optionally being modified or hydrogenated, or mixtures thereof; (c) 15 to 25 parts per weight of a plasticizer component, wherein the plasticizer component comprises paraffinic oils, naphthenic oils, polybutene, polybutadiene dibasic esters, polyols or mixtures thereof; and (d) 0.02 to 1.2 parts per weight of a light stabilizer, wherein the hot-melt adhesive has a density of between 0.790 and 1.2 g/cm.sup.3, a melt flow index of from 15 to 4000 g/min (1 kg at 200° C.), a viscosity of between 200 and 11,000 cPs at 160° C., measured by using a Brookfield RVT viscometer, spindle SC-4-27, according to ASTM D3236 (1999), a Shore hardness in the range of from 15 to 70 A at 23° C. according to ASTM D2240, and a softening point above 40° C. and not greater than 158° C. determined by ASTM E28, and wherein the hot-melt adhesive has an adhesion of 15N/25 mm or less, determined by peel adhesion (180°) or loop tack (23° C.) methods.

2. A pack comprising at least two packagings and a hot-melt adhesive, wherein each packaging of the at least two packagings is connected to at least one other packaging of the at least two packagings by adhesive bonding, the adhesive bonding being made by the hot-melt adhesive, and the hot-melt adhesive comprising: (a) 30 to 45 parts per weight of a polymer component, the polymer component comprising a styrene block copolymer, wherein the styrene block copolymer is selected from the group consisting of polystyrene-block-poly(ethylene-RAN-butylene)-block-polystyrene and a mixture of styrene-isoprene-styrene block copolymer and styrene-butylene-styrene block copolymer; (b) 30 to 50 parts per weight of a tackifying component, wherein the tackifying component comprises thermoplastic adhesive resin, aliphatic hydrocarbon, cycloaliphatic hydrocarbon, aromatic hydrocarbon, the respective hydrocarbon optionally being modified and/or hydrogenated, terpenes, the terpenes optionally being modified or hydrogenated, rosins, the rosins optionally being modified or hydrogenated, or mixtures thereof; (c) 15 to 25 parts per weight of a plasticizer component, wherein the plasticizer component comprises paraffinic oils, naphthenic oils, polybutene, polybutadiene dibasic esters, polyols or mixtures thereof; and (d) 0.02 to 1.2 parts per weight of a light stabilizer, wherein the hot-melt adhesive has a density of between 0.790 and 1.2 g/cm.sup.3, a melt flow index of from 15 to 4000 g/min (1 kg at 200° C.), a viscosity of between 200 and 11,000 cPs at 160° C., measured by using a Brookfield RVT viscometer, spindle SC-4-27, according to ASTM D3236 (1999), a Shore hardness in the range of from 15 to 70 A at 23° C. according to ASTM D2240, and a softening point above 40° C. and not greater than 158° C. determined by ASTM E28, wherein the hot-melt adhesive has an adhesion of 15N/25 mm or less, determined by peel adhesion (180°) or loop tack (23° C.) methods.

3. The pack, according to claim 2, wherein each packaging of the at least two packagings is a foodstuff packaging.

4. The pack according to claim 2, wherein one of the at least two packagings is a foodstuff container.

5. The pack according to claim 2, wherein one of the at least two packagings is selected from the group consisting of a bottle and a can.

6. The pack according to claim 5, wherein the one of the at least two packagings is a plastic bottle.

7. A method of adhesive bonding of at least a first packaging and a second packaging using a hot-melt adhesive, the method comprising first applying the hot-melt adhesive to one of either the first packaging or the second packaging, the hot-melt adhesive comprising: (a) 30 to 45 parts per weight of a polymer component, the polymer component comprising a styrene block copolymer, wherein the styrene block copolymer is selected from the group consisting of polystyrene-block-poly(ethylene-RAN-butylene)-block-polystyrene and a mixture of styrene-isoprene-styrene block copolymer and styrene-butylene-styrene block copolymer; (b) 30 to 50 parts per weight of a tackifying component, wherein the tackifying component comprises thermoplastic adhesive resin, aliphatic hydrocarbon, cycloaliphatic hydrocarbon, aromatic hydrocarbon, the respective hydrocarbon optionally being modified and/or hydrogenated, terpenes, the terpenes optionally being modified or hydrogenated, rosins, the rosins optionally being modified or hydrogenated, or mixtures thereof; (c) 15 to 25 parts per weight of a plasticizer component, wherein the plasticizer component comprises paraffinic oils, naphthenic oils, polybutene, polybutadiene dibasic esters, polyols or mixtures thereof; and (d) 0.02 to 1.2 parts per weight of a light stabilizer; and placing the other of either the first packaging or the second packaging in contact with the applied hot-melt adhesive, to thereby form a pack comprising the first packaging connected to the second packaging by the hot-melt adhesive by adhesive bonding, the adhesive bonding being made by the hot-melt adhesive, wherein the hot-melt adhesive has a density of between 0.790 and 1.2 g/cm.sup.3, a melt flow index of from 15 to 4000 g/min (1 kg at 200° C.), a viscosity of between 200 and 11,000 cPs at 160° C., measured by using a Brookfield RVT viscometer, spindle SC-4-27, according to ASTM D3236 (1999), a Shore hardness in the range of from 15 to 70 A at 23° C. according to ASTM D2240, and a softening point above 40° C. and not greater than 158° C. determined by ASTM E28, and wherein the hot-melt adhesive has an adhesion of 15N/25 mm or less, determined by peel adhesion (180°) or loop tack (23° C.) methods.

8. The method according to claim 7, wherein the first packaging and the second packaging are foodstuff packagings.

9. The method according to claim 8, wherein the foodstuff packagings are foodstuff containers.

10. The method according to claim 8, wherein the foodstuff packagings are selected from the group consisting of a bottle and a can.

11. The method according to claim 10, wherein the foodstuff a packagings are plastic bottles.

12. The method according to claim 7, wherein the light stabilizer is selected from the group consisting of a sterically hindered phenolic antioxidant and a sterically hindered amine.

13. The method according to claim 7, wherein the light stabilizer is pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

14. The method according to claim 7, wherein placing the other of either the first packaging or the second packaging in contact with the applied hot-melt adhesive provides a combination where the first packaging and the second packaging are detachably connected to each other.

Description

EXAMPLE

(1) TABLE-US-00002 Typical SBS/SIS Parts by Typical SEBS Parts by removable adhesive Weight % removable adhesive Weight % SIS Block-copolymer 20 SEBS Block-copolymer 31.4 15% styrene/melt flow 30% styrene/melt flow index (200° C./5 Kg) = 25 index (230° C./5 Kg) = 5 SBS Block-copolmyer 22.2 DCPD Resin 46 43% styrene-block- copolymer/melt flow index (200° C./5 kg = 25 White mineral oil 20 White mineral oil 22 Paraffin wax 62-68 5 Micro crystalline wax 0.5 DCPD resin 32 Antioxidant/stabilisor 0.1 package Stabiliser package 0.8 Peel adhesion 180° to  5.2N/25 mm Peel adhesion to PET 4.89N/25 mm PET initial after 24 hrs* Loop tack initial PET after 6.42N/25 mm Loop Tack  5.4N/25 mm 24 hrs at 23° C. * Peel adhesion l80° PET   15N/25 mm Peel adhesion l80° after 18.4N/25 mm after 28 days at 23° C. 28 days at 23° C. Loop tack after 28 days at 13.6N/25 mm Loop tack after 28 16.42N/25 mm  23° C. days at 23° C.

(2) A hot-melt adhesive for inventive use was prepared having the above composition, in particular comprising a mixture of styrene isoprene styrene (SIS) and styrene butylene styrene (SBS) styrenic block copolymer or comprising polystyrene-block-poly(ethylene-RAN-butylene)-block-polystyrene (SEBS). The adhesive properties of the resultant mixture were determined by peel adhesion and loop tack experiments at different times. It was found that by using the above hot-melt adhesive for adhesive bonding of PET packagings, an adhesion between the packaging containers is achieved allowing easy separation of the packagings without undue damaging thereof and simultaneously appropriate connecting the packagings before separation.

(3) All documents cited herein are incorporated in their entireties by reference.

(4) The features disclosed in the foregoing description and/or in the claims may, both separately and in any combination thereof, be material for realizing the invention in diverse forms thereof.