Method for homogenously incorporating filler into a self-adhesive compound, in particular a thermally crosslinkable self-adhesive compound, based on non-thermoplastic elastomer

Patent metadata

Field	Value
Publication number	US-12186941-B2
Application number	US-201917042340-A
Country	US
Kind code	B2
Filing date	Mar 15, 2019
Priority date	Mar 27, 2018
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

The invention relates to a method for homogenously incorporating filler into a self-adhesive compound, in particular a thermally crosslinkable self-adhesive compound, based on non-thermoplastic elastomer in a continuously working unit with a filling part and a compounding part. The self-adhesive compound contains at least one solid component, at least one liquid component, and at least one filler, and the method has the following steps: (a) feeding at least part of the at least one solid component, such as the non-thermoplastic elastomer in particular, and optionally part of the at least one liquid component to the filling part; (b) transferring the components of step (a) from the filling part to the compounding part; (c) optionally adding additional solid components or additional parts of the solid components to the compounding part; (d) adding the at least one liquid component to the compounding part if the liquid component was not already added to the filling part in step (a); (e) producing a homogenous self-adhesive compound in the compounding part; and (f) discharging the self-adhesive compound. The invention is characterized in that at least part of the at least one filler is pre-dispersed into at least one dispersion liquid in a separate unit and the dispersion obtained in this manner is added to the compounding part. The method prevents high sheering or frictional energies while introducing the filler into the compounding part of the continuously working unit and thus allows the use of temperature-sensitive components, such as temperature-sensitive chemical crosslinking agents in particular.

First claim

What is claimed is:

1. A process of homogeneously incorporating a filler into a thermally crosslinkable self-adhesive composition based on a non-thermoplastic elastomer in a continuously operating assembly with a feed section and with a compounding section having one or more sections downstream of the feed section, where the self-adhesive composition comprises at least one solid component, at least one liquid component and at least one filler, and where the process comprises the following steps:
(a) charging of at least one portion of the at least one solid component, and optionally of a portion of the at least one liquid component, into the feed section;
(b) transfer of the components from step (a) from the feed section into a section of the compounding section;
(c) optional addition of further solid components or of further portions of the solid components into the compounding section;
(d) addition of the at least one liquid component into the compounding section, insofar as not yet charged in step (a) into the feed section;
(e) production of a homogeneous self-adhesive composition in the compounding section; and
(f) discharge of the self-adhesive composition
wherein, at least a portion of the at least one filler is added after predispersion in at least one dispersion liquid in a separate assembly which is a multiscrew extruder having at least one barrel section the resultant dispersion being added into a section of the compounding section.

2. The process of claim 1 , wherein the dispersion liquid is at least one plasticizer selected from: oil, fat, plasticizing resin and/or tackifier resin.

3. The process of claim 1 , wherein at least one of the solid components is non-thermoplastic elastomer, thermoplastic elastomer, tackifier resin, thermal crosslinking agent and/or aging inhibitor.

4. The process of claim 1 , wherein at least one of the liquid components is non-thermoplastic elastomer, thermoplastic elastomer, plasticizer such as fat or oil, dye, plasticizing resin, tackifier resin and/or thermal crosslinking agent.

5. The process of claim 1 , wherein the non-thermoplastic elastomer is selected from the group of the natural rubbers, the randomly copolymerized styrene-butadiene rubbers (SBR), the butadiene rubbers (BR), the acrylonitrile-butadiene rubbers (NBR), the synthetic polyisoprenes (IR), the butyl rubbers (IIR), the halogenated butyl rubbers (XIIR), the acrylate rubbers (ACM), the ethylene-vinyl acetate copolymers (EVA), the polyolefins, the polyurethanes and blends thereof.

6. The process of claim 1 , wherein 10 to 50% by weight, based on the total elastomer content of the self-adhesive composition, of thermoplastic elastomer is charged alongside the non-thermoplastic elastomer.

7. The process according to claim 1 , wherein in the compounding section at least one thermal crosslinking agent selected from sulfur crosslinking systems, accelerated sulfur crosslinking systems, reactive phenolic resin crosslinking systems and diisocyanate crosslinking systems is added.

8. The process of claim 1 , wherein the filler is selected from oxides of alkali metals, oxides of alkaline earth metals or or oxides of transition metals, mixtures of these oxides and lignin.

9. The process of claim 1 , wherein the self-adhesive composition is produced without solvent.

10. The process of claim 1 , wherein the continuously operating assembly is a multiscrew extruder, and where the compounding section of the multiscrew extruder includes at least two coupled planetary barrel sections.

11. The process of claim 10 , wherein the planetary barrel section of the planetary-gear extruder comprises at least half of the possible number of planetary spindles which may be present with the planetary barrel section.

12. The process of claim 1 , wherein the entire quantity of the at least one filler is predispersed in the at least one dispersion liquid.

13. The process of claim 1 , wherein the temperature of the self-adhesive composition on discharge from the continuously operating assembly is not in excess of 125° C.

14. The process of claim 1 , wherein the self-adhesive composition is coated onto a material which takes the form of a web.

15. The process of claim 14 , wherein the coating of the material which takes the form of a web is achieved with a roll unit or calender unit, where the self-adhesive composition is molded to the desired thickness during passage through one or more nips prior to transfer onto the material which takes the form of a web.

16. The process of claim 14 , wherein in a process step downstream of the coating procedure, the self-adhesive composition is crosslinked.

17. A self-adhesive composition formed by the process of claim 1 .

18. The process of claim 16 , wherein the self-adhesive composition is thermally crosslinked.

19. The process of claim 2 , wherein the dispersion liquid is at least one tackifier resin.

Assignees

• Tesa Se

Inventors

• Massow Klaus
• Köpke Tillmann

Classifications

• C09J11/04

  inorganic · CPC title

• B29K2105/0097

  Glues or adhesives, e.g. hot melts or thermofusible adhesives · CPC title

• B29K2105/0038

  Plasticisers · CPC title

• B29K2021/003

  Thermoplastic elastomers · CPC title

• B29B7/603

  in measured doses, e.g. proportioning of several materials · CPC title