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CN-116806279-B - Method for producing a water-repellent coating on a textile substrate using a plasma generated by a hollow cathode

CN116806279BCN 116806279 BCN116806279 BCN 116806279BCN-116806279-B

Abstract

The present invention relates to a hollow cathode plasma polymerization process for application to a textile substrate, in particular a process for applying a halogen-free, in particular fluorine-free, water-repellent polymer coating, in particular a durable water-repellent coating, to a textile substrate, and to products obtainable by such a process and system.

Inventors

  • G. ARNDT

Assignees

  • 旭硝子欧洲玻璃公司

Dates

Publication Date
20260505
Application Date
20220207
Priority Date
20210212

Claims (19)

  1. 1. A method for producing a water-repellent coating on a textile substrate, the method comprising the stages comprising: providing at least one vacuum chamber; Providing a fabric substrate; Providing a first plasma source of the linear hollow cathode type comprising at least one pair of hollow cathode plasma generating electrodes connected to an AC, DC or pulsed DC generator for depositing the water repellent coating on the fabric substrate; injecting a first plasma-generating gas into an electrode of the first plasma source at a flow rate between 500 and 2500sccm per linear meter of plasma of the first plasma source; applying a first power to the first plasma source such that a first power density of the plasma is between plasma 3kW and 15kW of the first plasma source per linear meter; Injecting organosilane monomer into the plasma at a flow rate between 100 and 1000sccm per linear meter of the plasma of the first plasma source, the organosilane monomer being injected into the plasma at least between the electrodes of each electrode pair of the first plasma source; A water-repellent coating is deposited on a surface of the fabric substrate by exposing the fabric substrate to a plasma of the first plasma source.
  2. 2. The method of claim 1, further comprising a stage comprising: Providing a second plasma source of the linear hollow cathode type comprising at least one pair of hollow cathode plasma generating electrodes connected to an AC, DC or pulsed DC generator for surface activation of the textile substrate; injecting a second plasma-generating gas into an electrode of the second plasma source at a flow rate between 1500 and 4500 sccm per linear meter of the second plasma source; supplying a second power to the second plasma source such that a second power density of the plasma is between 5 kW and 15 kW per linear meter of the plasma of the second plasma source, and Activating the surface of the fabric substrate by exposing the fabric substrate to a plasma of the second plasma source, and then depositing the water-repellent coating on the surface of the fabric substrate by exposing the fabric substrate to a plasma of the second plasma source.
  3. 3. The method according to claim 1, characterized in that the organosilane monomer is an organosilane according to: a.Y 1 -X-Y 2 where X is O or NH, Y 1 is-Si (Y 3 )(Y 4 )Y 5 and Y 2 is Si (Y 3' )(Y 4' )Y 5' where Y 3 、Y 4 、Y 5 、Y 3' 、Y 4' and Y 5' are each independently H or alkyl having up to 10 carbon atoms; where at most one of Y 3 、Y 4 and Y 5 is hydrogen and at most one of Y 3' 、Y 4' and Y 5' is hydrogen and the total number of carbon atoms does not exceed 20; or B. - [ Si (CH 3 ) q (H) 2-q -X-] n -, which is a cyclic monomer in the case of n of 2 to 10, wherein q is 0 to 2 and wherein the total number of carbon atoms does not exceed 20; or Ch 2 =C(R 1 )-Si(R 2 )(R 3 )-R 4 , wherein R 1 is H or alkyl, and wherein R 1 、R 2 and R 3 are each independently H, alkyl having up to 10 carbon atoms, or straight, branched or cyclic alkoxy, or D.R 5 -Si(R 6 )(R 7 )-R 8 , wherein R 5 is H or alkyl, and wherein R 6 、R 7 and R 8 are each independently H, alkyl having up to 10 carbon atoms, or straight-chain, branched or cyclic alkoxy, or Ch 2 =C(R 9 )C(O)-O-(CH 2 ) p -Si(R 10 )(R 11 )-R 12 , wherein R 9 is H or alkyl, wherein p is from 0 to 10, and wherein R 10 、R 11 and R 12 are each independently H, alkyl having up to 10 carbon atoms, or straight, branched or cyclic alkoxy.
  4. 4. The method of claim 1 or 2, further comprising deaerating the fabric substrate.
  5. 5. The method of claim 1 or 2, wherein the fabric substrate is a fabric on a roll treated in a roll-to-roll process.
  6. 6. The method of claim 2, wherein the second plasma-generating gas comprises a mixture of N 2 、O 2 、O 2 and N 2 , or N 2 O.
  7. 7. The method of claim 1, wherein the first plasma-generating gas comprises He, ar, or a mixture of He and Ar.
  8. 8. The method of claim 7, wherein the first plasma-generating gas comprises a mixture of He and Ar, wherein the atomic ratio He/Ar is between 0.5 and 10.
  9. 9. The method of claim 2, wherein exposing the fabric substrate to the plasma of the second plasma source is for a time comprised between 4 and 12 s.
  10. 10. The method of claim 1, wherein a ratio of the first plasma-generating gas flow rate to the organosilane monomer flow rate is at least 1.
  11. 11. A method according to claim 1 or 2, wherein the temperature of the fabric substrate is at most 40 ℃.
  12. 12. A method according to claim 1 or 2, wherein the textile is a shaped three-dimensional shaped finished textile treated in a batch process.
  13. 13. The method of claim 1 or 2, wherein the method is performed at an operating pressure comprised between 5 and 50 mtorr.
  14. 14. The method of claim 12, wherein the three-dimensional shaped finished textile after shaping is a garment.
  15. 15. The method of claim 12, wherein the three-dimensional shaped finished textile after shaping is a trim.
  16. 16. A method according to claim 3, wherein the alkoxy group is-O-Z, wherein Z is-C t H 2t+1 , wherein t is 1 to 10.
  17. 17. A method according to claim 3, wherein R 1 is-CH 3 .
  18. 18. A method according to claim 3, wherein R 5 is-CH 3 .
  19. 19. A method according to claim 3, wherein R 9 is-CH 3 .

Description

Method for producing a water-repellent coating on a textile substrate using a plasma generated by a hollow cathode Technical Field The present invention relates to a hollow cathode plasma polymerization process for application to a textile substrate, in particular to a process, a system and use for applying a halogen-free (in particular fluorine-free) water-repellent polymer coating, in particular a durable water-repellent coating, to a textile substrate, and to products obtainable by such a process and system. Background Substrates having water repellency are desirable in many textile applications and have been manufactured for some time. Waterproof generally means the ability of a textile to prevent water from penetrating into the textile fibers. The water repellency should not be confused with the pure hydrophobicity of the fibers comprising the textile and is assessed by a suitable method, such as the method described below for the purposes of the present invention. Examples include raincoats, interior trim applications, carpeting, and the like. These articles are typically manufactured by applying a suitable fluorocarbon polymer to the surface of a textile, followed by drying and curing the substrate to properly align the fluorochemical segments of the polymer. Suitable polymers are available from 3M company, duPont company (DuPont) and various other manufacturers. The fluorochemical also helps reduce the tendency of water to adhere to the substrate fibers. These fluorochemicals typically include a fluorinated component and a non-fluorinated polymer backbone. An important feature of the polymer backbone is its ability to form durable films on the fiber surface. There have been significant efforts to produce textile substrates having water repellency characteristics that do not necessarily rely on fluorinated polymers that are environmentally problematic. For example, document EP 3101170 A1 discloses a low pressure plasma polymerization process for applying fluorine-free durable water repellent polymer nanocoating onto a textile substrate. These products initially provide a sufficient degree of water repellency to certain textiles, but the coatings tend to lack durability in many applications. Durability is defined herein as retaining an acceptable level of water repellency over a reasonable number of care cycles. Furthermore, the plasma polymerization process of EP 3101170 A1 is slow and difficult to combine with other surface treatments and/or continuous processes, as it generates a plasma in the whole vacuum chamber. Specifically, for the purposes of the present application, durability is defined as having a spray rating (according to standard ISO4920 (2012)) of at least 3.0 to 3.5 after 5 wash cycles (according to ISO6330 (2012), as outlined and referenced below). Accordingly, there is a need in the art to provide a method for coating textiles with environmentally friendly, in particular fluorine-free, water-repellent coatings that increase the water repellency of the textiles and provide sufficient water repellency even after several washing cycles. Disclosure of Invention The object of the present invention is to provide a solution to the problem of providing a textile substrate with a preferably durable water-repellent coating which is sufficiently water-repellent even after several washing cycles. Furthermore, the present invention provides a method without any halogen-containing, in particular any fluorine-containing, chemical. The resulting water-repellent coating is halogen-free, in particular fluorine-free. Another object of the invention is to provide a fast method in that it completes the coating process in a very short time. The present invention solves the above-mentioned technical problem by providing a method for depositing a halogen-free water-repellent coating on a textile substrate with organosilane monomers by means of a low-pressure hollow-cathode plasma polymerization process. The low pressure hollow cathode plasma polymerization process of the present invention is particularly effective because it provides a plasma directly in a limited space above the substrate and is capable of doing so without heating the substrate to the point where it is necessary to cool the substrate. Drawings These and further aspects of the invention will be explained in more detail, by way of example, and with reference to the appended drawings, in which: Fig. 1 shows a schematic cross section of a hollow cathode type plasma source for use in the present invention, the plasma source comprising a pair of electrodes. Fig. 2 shows a section of a roll-to-roll coating apparatus for carrying out the method of the invention. The figures are not drawn to scale. Detailed Description The present invention relates to a method for producing a water-repellent coating on a textile substrate, comprising the following stages: Providing a fabric substrate; providing a first plasma source of the linear hollow cathode ty