Protective elements made of polyolefin hot-melt adhesives

Patent metadata

Field	Value
Publication number	US-9725627-B2
Application number	US-201514597577-A
Country	US
Kind code	B2
Filing date	Jan 15, 2015
Priority date	Jul 17, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The use of a hot-melt adhesive as a protective element for objects is disclosed, wherein the hot-melt adhesive contains over 80 wt. % of at least one modified polyolefin copolymer produced from a high-molecular-weight polyolefin copolymer by thermomechanical degradation of the polymer under shear stress and/or heating, wherein the viscosity of the copolymer is reduced, and up to 20 wt. % of additives and auxiliary substances, wherein the adhesive has a softening point from 70 to 150° C.

First claim

The invention claimed is:

1. A protective coating element prepared from a hot-melt adhesive comprising:
(a) greater than 80 wt. % of at least one modified polyolefin copolymer produced by thermomechanically degrading a high-molecular-weight polyolefin copolymer under shear stress and/or heating, whereby the viscosity of the copolymer is reduced, and
(b) up to 20 wt. % of an additive and auxiliary;
wherein the adhesive has a softening point from 70 to 150° C.

2. The protective coating element according to claim 1 , characterized in that the hot-melt adhesive has a viscosity from 200 to 10,000 mPas at 200° C.

3. The protective coating element according to claim 1 , characterized in that the polyolefin copolymer is selected from propylene/ethylene copolymers, propylene/butylene copolymers, ethylene/butylene copolymers or a corresponding terpolymer having an MFI of below 50 g/10 min (230° C., 2.16 kg).

4. The protective coating element according to claims 1 , characterized in that the adhesive has an ultimate elongation value of greater than 10% and the adhesive has a force value of less than 1 N/mm.

5. The protective coating element according to claim 1 , characterized in that the adhesive comprises less than 10 wt. % of additives and auxiliary substances, selected from resins, adhesion promoters or wax.

6. An object comprising a substrate and a protective coating element produced from a hot-melt adhesive comprising (a) greater than 80 wt. % of at least one modified polyolefin copolymer produced by thermomechanically degrading a high-molecular-weight polyolefin copolymer under shear stress and/or heating, and (b) up to 20 wt. % of an additive and auxiliary,
wherein the adhesive has an adhesion value below 1 N/mm.

7. The object according to claim 6 , wherein the protective coating element can be removed from the substrate without any residue.

8. A method for coating an object with a protective coating element comprising the steps of:
(a) preparing a melt of the protective coating elements by (i) thermomechanically degrading a high-molecular-weight polyolefin copolymer under shear stress and/or heating and (ii) combining up to 20 wt % of an an additive and auxiliary to the copolymer;
(b) applying the melt onto a substrate at a temperature from 80 to 150° C.; and
(c) cooling the melt.

9. The object of claim 6 , wherein protective coating element has a thickness of from 0.5 to 20 mm.

Assignees

• Henkel Ag & Co Kgaa

Inventors

• Blodig Claudia

Classifications

• C08F8/50

  Partial depolymerisation · CPC title

• C08K5/14

  Peroxides · CPC title

• B29C48/875

  for achieving a non-uniform temperature distribution, e.g. using barrels having both cooling and heating zones · CPC title

• B29C2948/92704

  Temperature · CPC title

• B29B7/421

  with screw and additionally other mixing elements on the same shaft, e.g. paddles, discs, bearings, rotor blades of the Banbury type · CPC title