Method for making patterned light-blocking elements

A method of making a patterned light-blocking element, the method comprising, the following A′) through F′):

• A′) providing a i) fabric having a face side and a back side, and also having no prefabricated visible relief pattern on either the face side or the back side;
• B′) disposing a foamed aqueous opacifying composition onto the back side of the i) fabric;
• C′) drying the disposed foamed aqueous opacifying composition to provide a dried foamed opacifying layer;
• D′) embossing and densifying the dried foamed opacifying layer to reduce its thickness by at least 20% compared to its original thickness, while the dried foamed opacifying layer and the i) fabric are in intimate contact between a pair of pressure rollers,
• wherein embossing is carried out using a continuous patterned embossing belt that is situated between the pair of pressure rollers, the continuous patterned embossing belt having a prefabricated visible relief pattern that is in contact with the face side of the i) fabric, and has both raised regions and recessed regions,
• to provide an ii) embossed and densified foamed opacifying layer on the back side of the i) fabric, the ii) embossed and densified foamed opacifying layer having a visible relief image of raised regions and recessed regions, such that in low ambient lighting conditions, backlighting impacting the ii) embossed and densified foamed opacifying layer is blocked everywhere except in at least some of the recessed regions of the visible relief pattern, and such that an outline of the visible relief pattern in the ii) embossed and densified foamed opacifying layer is visible when viewed from the face side of the i) fabric;
• and
• either a following order of E′) and F′) or a reverse order of F′) and E′), to form a patterned light-blocking element,
• E′) disposing and drying a iii) non-foamed functional composition on the ii) embossed and densified foamed opacifying layer at a coverage of at least 0.5 g/m2 and up to and including 10 g/m2;
• and
• F′) curing the disposed and dried iii) non-foamed functional composition and the ii) embossed and densified foamed opacifying layer on the back side of the i) fabric,
• wherein
• the cured ii) embossed and densified foamed opacifying layer comprises:
• (a) porous particles that are present in an amount of at least 0.1 weight % and up to and including 35 weight %, each porous particle comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm and a porosity of at least 20 volume % and up to and including 70 volume %;
• (b′) a binder matrix that is present in an amount of at least 10 weight % and up to and including 80 weight %;
• (c) two or more additives that are present in a total amount of at least 0.0001 weight % and up to and including 40 weight %, the two or more additives comprising at least one foaming surfactant and at least one compound that is a foam stabilizer;
• and
• (e) an opacifying colorant that is present in an amount of at least 0.0001 weight % and up to and including 3 weight %, the opacifying colorant being a different material from all of the (a) porous particles, (b′) binder matrix, and (c) two or more additives, and which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm,
• all amounts of the (a) porous particles, (b′) binder material, (c) two or more additives, and (e) opacifying colorant being based on the total weight of the cured ii) embossed and densified foamed opacifying layer,
• wherein the disposed, dried, and cured iii) non-foamed functional composition comprises (aa) glass particles or organic polymeric particles having a mode particle size of at least 5 μm and up to and including 100 μm, in an amount of at least 5 weight % and up to and including 99 weight %, based on the total weight of the disposed, dried, and cured iii) non-foamed functional composition;
• and (ad) one or more water-soluble or water-dispersible organic polymeric binders, and
• wherein the optical density of the patterned light-blocking element is greater than 4 in the recessed regions of the visible relief image of the cured ii) embossed and densified foamed opacifying layer.

A method of making a patterned light-blocking element, the method comprising, the following A″) through G″):

• A″) providing a i) fabric having a face side and a back side, and having no prefabricated visible relief pattern on either the face side or the back side;
• B″) disposing a foamed aqueous opacifying composition onto the back side of the i) fabric;
• C″) drying the disposed foamed aqueous opacifying composition to provide a dried foamed opacifying layer;
• D″) densifying the dried foamed opacifying layer to reduce its thickness by at least 20% compared to its original thickness, while the dried foamed opacifying layer and the i) fabric are in intimate contact between a pair of pressure rollers, to provide a densified foamed opacifying layer on the back side of the i) fabric;
• and
• either a following order of E″) and F″) or a reverse order F″ and E″), but both before G″),
• E″) disposing and drying a iii) non-foamed functional composition on the densified foamed opacifying layer at a coverage of at least 0.5 g/m2 and up to and including 10 g/m2;
• F″) curing the disposed and dried iii) non-foamed functional composition, if present, and the densified foamed opacifying layer on the back side of the i) fabric, to form a cured and densified foamed opacifying layer;
• and
• G″) embossing the disposed, dried, and cured iii) non-foamed functional composition and the cured and densified foamed opacifying layer, while the i) fabric and the cured and densified foamed opacifying layer are in intimate contact between a pair of pressure rollers, wherein embossing is carried out using an embossing means that is either one of the pair of pressure rollers or is a means situated between the pair of pressure rollers, the embossing means having a prefabricated visible relief pattern that is in contact with the face side of the i), the prefabricated visible relief pattern having both raised regions and recessed regions,
• to provide a cured ii) embossed and densified foamed opacifying layer on the back side of the i) fabric, and to provide a patterned light-blocking element,
• the cured ii) embossed and densified foamed opacifying layer having a visible relief pattern of raised regions and recessed regions, such that in low ambient lighting conditions, backlighting impacting the cured ii) embossed and densified foamed opacifying layer is blocked everywhere except in at least some of the recessed regions of the visible relief pattern, and such that an outline of the visible relief pattern in the cured ii) embossed and densified foamed opacifying layer is visible when viewed from the face side of the i) fabric,
• wherein the cured ii) embossed and densified foamed opacifying layer comprises:
• (a) porous particles that are present in an amount of at least 0.1 weight % and up to and including 35 weight %, each porous particle comprising a continuous polymeric phase and discrete pores dispersed within the continuous polymeric phase, the porous particles having a mode particle size of at least 2 μm and up to and including 50 μm and a porosity of at least 20 volume % and up to and including 70 volume %;
• (b′) a binder matrix that is present in an amount of at least 10 weight % and up to and including 80 weight %;
• (c) two or more additives that are present in a total amount of at least 0.0001 weight % and up to and including 40 weight %, the two or more additives comprising at least one foaming surfactant and at least one compound that is a foam stabilizer;
• and
• (e) an opacifying colorant that is present in an amount of at least 0.0001 weight % and up to and including 3 weight %, the opacifying colorant being a different material from all of the (a) porous particles, (b′) binder matrix, and (c) two or more additives, and which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm,
• all amounts of the (a) porous particles, (b′) binder material, (c) two or more additives, and (e) opacifying colorant being based on the total weight of the cured ii) embossed and densified foamed opacifying layer,
• wherein the disposed, dried, and cured iii) non-foamed functional composition comprises (aa) glass particles or organic polymeric particles having a mode particle size of at least 5 μm and up to and including 100 μm, in an amount of at least 5 weight % and up to and including 99 weight %, based on the total weight of the disposed, dried, and cured iii) non-foamed functional composition;
• and (ad) one or more water-soluble or water-dispersible organic polymeric binders, and
• wherein the optical density of the patterned light-blocking element is greater than 4 in regions outside of the recessed regions of the visible relief image in the cured ii) embossed and densified foamed opacifying layer.