Photocurable color changing compositions and method of forming features on a membrane surface using the same
AssigneeHenkel AG & Co. KGaA
InventorsShuhua Jin, Jesse Lawrence Davis, Chih-Min Cheng, Zhongwei Liu, Daniel Yi, Tomoyo Wakamatsu
Life of this patent
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Abstract
Photocurable compositions that have a color change during curing and methods of preparation and use of such compositions. More particularly, the present invention relates to photocurable compositions that that have a color change during curing and are useful for forming topographical features, e.g., spacer features, and/or fold protection coatings on a portion of a membrane surfaces, and particularly on membranes used in osmosis and reverse-osmosis applications, such as membrane filters.
Claims11
A filtration membrane, comprising:
- a surface on the membrane;
- and
- a photocurable, color changing composition disposed on at least part of the membrane surface, the composition comprising:
- a. from 20 to 60 wt. % of an acrylate oligomer;
- b. from 10 to 60 wt. % of a diluent;
- c. a cure system comprising from 0.1 to 5 wt. % of a polymeric thioxanthone derivative photoinitiator and from 0.1 to 5 wt. % of an aromatic tertiary amine com photoinitiator;
- d. optionally from 0 to 60 wt. % of a filler;
- and
- e. optionally from 0 to 20 wt. % of one or more additives;
- wherein the photocurable, color changing composition does not include phosphine oxide;
- wherein the photocurable, color changing composition disposed on the surface is cured and exhibits a color change during curing, and after 24 hours of storage in the absence of UV light the color fades, while the faded composition changes color during a subsequent exposure to . . . actinic radiation, and wherein the composition after curing is a yellow to orange color.
A method of forming topographical features on a membrane surface comprising:
- providing a membrane surface;
- providing a stencil or screen over the membrane surface, the stencil or screen having openings exposing the membrane surface for receiving a curable composition;
- providing a light curable color changing composition, comprising:
- a. from 20 to 60 wt. % of an acrylate oligomer;
- b. from 10 to 60 wt. % of a diluent;
- c. a cure system comprising from 0.1 to 5 wt. % of a polymeric thioxanthone derivative photoinitiator and
- from 0.1 to 5 wt. % of an aromatic tertiary amine co-photoinitiator;
- d. optionally from 0 to 60 wt. % of a filler;
- and
- e. optionally from 0 to 20 wt. % of one or more additives;
- wherein the curable composition does not include phosphine oxide;
- wherein the curable composition exhibits
- a color change during curing;
- depositing one or more layers of the curable composition into the stencil openings or screen openings and onto the membrane surface to form the topographical features, the openings defining an approximate shape and size of the topographical features;
- removing the stencil or screen to leave in place the topographical features on the membrane;
- and
- exposing the curable composition to actinic radiation to cure the composition,
- wherein a single layer of the curable composition deposited in the depositing step produces topographical features have an aspect ratio (height/width) from about 0.2 to about 2.
A method of checking the cure of a polymer based feature on a filtration membrane, comprising:
- providing a membrane have a surface;
- providing a light curable color changing composition, comprising:
- from 20 to 60 wt. % of an acrylate oligomer;
- from 10 to 60 wt. % of a diluent;
- a cure system comprising from 0.1 to 5 wt. % of a polymeric thioxanthone derivative photoinitiator and from 0.1 to 5 wt. % of an aromatic tertiary amine co-photoinitiator;
- optionally from 0 to 60 wt. % of a filler;
- and
- optionally from 0 to 20 wt. % of one or more additives;
- wherein the composition does not include phosphine oxide;
- coating the composition on a portion of the membrane surface;
- and
- exposing the coated composition to actinic radiation to cure the coated composition and form the cured feature, wherein the composition changes color during curing;
- and
- evaluating the degree of cure of the cured composition by the color of the composition.
Dependencies are inferred from the claim text.