Packaged viscoelastic polymer substance

Patent metadata

Field	Value
Publication number	US-11987409-B2
Application number	US-201917293652-A
Country	US
Kind code	B2
Filing date	Nov 13, 2019
Priority date	Nov 13, 2018
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

Packaged viscoelastic polymer substances and methods for the production of the packaged viscoelastic polymer substances are provided. The packaged viscoelastic polymer substances are further processable under the influence of heat and shear.

First claim

The invention claimed is:

1. A method for producing a packaged viscoelastic polymer substance, the method comprising:
a) plastifying a viscoelastic polymer substance at elevated temperatures, the viscoelastic polymer substance being a polymer substance based on poly(meth)acrylates having a weight-average molecular weight of 500,000 g/mol or more;
b) continuously dispensing the plastified viscoelastic polymer substance into a protective polymer film, the protective polymer film having no self-adhesive properties and having been brought into a tubular form before said continuous dispensing so as to be filled with the plastified viscoelastic polymer substance, thereby forming a strandlike polymer assembly having a diameter of 55 to 70 mm, a core of the plastified viscoelastic polymer substance, and a shell of the protective polymer film, wherein a fraction of the protective polymer film, based on a total weight of the protective polymer film and the plastified viscoelastic polymer substance, is less than 1.0 wt %, and wherein the plastified viscoelastic polymer substance has a viscosity of more than 100 Pas during said continuous dispensing into the tubular protective polymer film;
c) converting the strandlike polymer assembly into a flattened strandlike polymer assembly with a smallest cross-section having a ratio of width to height of about 2:1 to 7:1;
d) cooling the flattened strandlike polymer assembly to a temperature at which the strandlike polymer assembly is still plastically deformable; and
e) converting the cooled flattened strandlike polymer assembly at the plastically deformable temperature by squeezing into an elongate polymer assembly comprising a multiplicity of squeeze points, the squeeze points subdividing the polymer assembly into a multiplicity of first regions and a multiplicity of second regions, wherein each of the first regions have a length of at least about 300 mm and a cross-section of the first regions corresponds substantially to a cross-section of the strandlike polymer assembly, wherein the second regions are formed by the squeeze points with thicknesses resulting from thicknesses of the protective polymer film and the viscoelastic polymer substance that remains in regions of the squeeze points, and wherein the second regions have a length corresponding to once to twice a maximum extent along the cross-section of the first regions.

2. The method of claim 1 , wherein the converting of the strandlike polymer assembly into the flattened strandlike polymer assembly in step c) is carried out by means of rolls.

3. The method of claim 1 , wherein the cooling in step d) is carried out down to a core temperature of less than 100° C.

4. The method of claim 1 , wherein the strandlike polymer assembly after step e) is deposited in a container, wherein a direction of deposition of the elongate polymer assembly into the container changes at the squeeze points.

5. The method of claim 1 , wherein step d) takes place in a water bath.

6. The method of claim 1 , wherein the plastifying in step a) is carried out in an extruder.

7. The method of claim 1 , wherein the plastified viscoelastic polymer substance has a viscosity of more than 250 Pas during said continuous dispensing into the protective polymer film.

8. The method of claim 1 , wherein the fraction of the protective polymer film in step b), based on the total weight of the protective polymer film and plastified viscoelastic polymer substance, is less than 0.5 wt %.

9. The method of claim 1 , wherein the protective polymer film consists of polyethylene, polypropylene, ethylene-vinyl acetate, or a mixture thereof.

10. The method of claim 1 , wherein the viscoelastic polymer substance is a self-adhesive substance or is convertible into a self-adhesive substance.

11. The method of claim 1 , wherein the viscoelastic polymer substance has a density at 25° C. of 1.05 to 1.3 g/cm 3 .

12. A method comprising:
plastifying the packaged viscoelastic polymer substance formed according to claim 1 under the influence of heat and shear.

13. The method of claim 12 , further comprising:
treating the packaged viscoelastic polymer substance with said heat and shear such that the protective polymer film is plastified.

14. The method of claim 12 , wherein the treatment with heat and shear is carried in an extruder.

Assignees

• Tesa Se

Inventors

• Massow Klaus
• Lass Volker
• Brandes Kay

Classifications

• B65B29/00 Primary

  Packaging of materials presenting special problems · CPC title

• B29C48/0011

  combined with compression moulding · CPC title

• B29C48/0019

  combined with shaping by flattening, folding or bending · CPC title

• B29C48/0022

  combined with cutting · CPC title

• B29C48/919

  using a bath, e.g. extruding into an open bath to coagulate or cool the material · CPC title