Method for applying a material containing a meltable polymer, more particularly a hot-melt adhesive, above the decomposition temperature thereof

Patent metadata

Field	Value
Publication number	US-12168319-B2
Application number	US-201916965717-A
Country	US
Kind code	B2
Filing date	Feb 13, 2019
Priority date	Feb 16, 2018
Publication date	Dec 17, 2024
Grant date	Dec 17, 2024

Abstract

The invention relates to a method for applying a material containing a meltable polymer comprising the step of applying a filament of the at least partially molten material from a discharge opening of a discharge element onto a substrate. The meltable polymer has the following properties: —a melting point (DSC, differential scanning calorimetry; second heating with a heating rate of 5° C./min) in a range from ≥40° C. to ≤120° C.; —a glass transition temperature (DMA, dynamic mechanical analysis in accordance with DIN EN ISO 6721-1:2011) in a range from ≥−70° C. to ≤30° C.; —a storage modulus G′ (parallel plate oscillation viscometer in accordance with ISO 6721-10:2015 at a frequency of 1/s) at 20° C. above the melting point of ≥1·10 4 Pa; —a storage modulus G′ (parallel plate oscillation viscometer in accordance with ISO 6721-10:2015 at a frequency of 1/s) at 10° C. below the melting point with prior heating to a temperature of 20° C. above the melting point and subsequent cooling with a cooling rate of 1° C./min of ≤1·10 7 Pa; wherein the filament has an application temperature of ≥100° C. above the melting point of the meltable polymer for ≤5 minutes during the application process and wherein the meltable polymer further has the property that the storage modulus G′ (parallel plate oscillation viscometer in accordance with ISO 6721-10:2015 at a frequency of 1/s) of the meltable polymer at the highest application temperature reached during the application process is smaller by a factor of ≥10 than the storage modulus G′ (parallel plate oscillation viscometer in accordance with ISO 6721-10:2015 at a frequency of 1/s) at a temperature of 20° C. above the melting point of the meltable polymer.

First claim

The invention claimed is:

1. A method of applying a material comprising a fusible polymer, comprising:
applying a filament of the fusible polymer comprising an at least partly molten material from a discharge opening of a discharge element to a substrate;
wherein the fusible polymer has the following properties:
a melting point within a range from ≥40° C. to ≤120° C. based on a differential scanning calorimetry 2nd heating at a heating rate of 5° C./min;
a glass transition temperature within a range from ≥−70° C. to ≤30° C. based on dynamic-mechanical analysis according to DIN EN ISO 6721-1:2011;
a storage modulus G′ at 20° C. above the melting point of ≥1·10 4 Pa based on ISO 6721-10:2015 using a plate/plate oscillation viscometer at a frequency of 1/s;
a storage modulus G′ at 10° C. below the melting point with prior heating to a temperature of 20° C. above the melting point and subsequent cooling at a cooling rate of 1° C./min of ≤1·10 7 Pa based on ISO 6721-10:2015 using a plate/plate oscillation viscometer at a frequency of 1/s;
wherein the filament is applied at an application temperature of ≥100° C. above the melting point of the fusible polymer for ≤5 minutes,
wherein, at a maximum application temperature attained during melting of the fusible polymer, the fusible polymer has a storage modulus G′ that is smaller by a factor of ≥10 than the storage modulus G′ at a temperature of 20° C. above the melting point of the fusible polymer based on ISO 6721-10:2015 using a plate/plate oscillation viscometer at a frequency of 1/s, and
wherein the fusible polymer comprises at least one of polyurethane, polyester, or a combination thereof.

2. The method as claimed in claim 1 , further comprising applying the filament at a rate of 150 mm/s.

3. The method as claimed in claim 1 , wherein the fusible polymer is selected such that, after storage at the maximum application temperature attained for a duration of ≤1 hour, the storage modulus G′ more than doubles, or else the storage modulus G′ falls to a value of less than half of a starting value based on ISO 6721-10:2015 using a plate/plate oscillation viscometer at a frequency of 1/s.

4. The method as claimed in claim 1 , further comprising heating the material from a temperature of ≤40° C. to the maximum application temperature within ≤5 minutes prior to applying the material.

5. The method as claimed in claim 1 , further comprising heating the material within the discharge element to the maximum application temperature, such that a viscosity of the material decreases at least by a factor of 10.

6. The method as claimed in claim 1 , wherein a distance between a surface of the substrate and the discharge opening of the discharge element is ≤1 mm.

7. The method as claimed in claim 1 , further comprising contacting and passing the discharge element with its discharge opening over the substrate at a constant pressure.

8. The method as claimed in claim 1 , further comprising applying the material to the substrate at a pressure of ≥0.5 bar.

9. The method as claimed in claim 1 , wherein the fusible polymer comprises a polyurethane obtained from a reaction of a polyisocyanate component and a polyol component, wherein the polyol component includes a polyesterpolyol having a no-flow point of ≥25° C. based on ASTM D5985.

10. The method as claimed in claim 1 , wherein the fusible polymer, after heating to 20° C. above its melting point and cooling to 20° C. at a cooling rate of 4° C./min, within a temperature interval from 25° C. to 40° C. for ≥1 minute, has a storage modulus G′ of ≥100 kPa to ≤10 MPa and, after cooling to 20° C. and storage at 20° C. for 120 minutes, has a storage modulus G′ of 20 MPa based on ISO 6721-10:2015 using a plate/plate oscillation viscometer at a frequency of 1/s.

11. The method as claimed in claim 1 , further comprising contacting the material with a second substrate after applying the material.

12. The method as claimed in claim 11 , wherein the second substrate includes a hotmelt adhesive that contacts the material.

13. The method as claimed in claim 1 , wherein the method is a method of producing an article from the material, the method of producing the article from the material comprising:
I) applying the filament of the at least partly molten material to a carrier to obtain a layer of the material, corresponding to a first selected cross section of the article;
II) applying a filament of the at least partly molten material to a previously applied layer of the material to obtain a further layer of the material, corresponding to a further selected cross section of the article and bonded to the layer applied beforehand;
III) repeating II) until the article has been formed.

14. The method as claimed in claim 1 , wherein the substrate is a textile, a foil, a paper, a cardboard, a foam, a mold component, part of a shoe, a circuit board for electronic circuits, an electronics housing part, or an electronic component.

15. The method as claimed in claim 1 , wherein the fusible polymer comprises an anionic polyurethane.

Assignees

• Covestro Intellectual Property Gmbh & Co Kg

Inventors

• Achten Dirk
• Buesgen Thomas
• Tillack Joerg
• Reichert Peter
• Degiorgio Nicolas
• Melchiors Martin
• Arndt Wolfgang

Classifications

• C09J175/06

  from polyesters · CPC title

• C08G2170/20

  Compositions for hot melt adhesives · CPC title

• C08G18/3221

  hydroxylated esters of carboxylic acids other than higher fatty acids · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/118 Primary

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title