Light-blocking articles from foamed composition containing solid polymeric particles
A foamed, opacifying element has a substrate with opposing planar surfaces and a foamed opacifying layer disposed on one opposing surface. The foamed opacifying layer contains (a) 0.1-80 weight % of nonporous polymeric particles; (b′) 10-80 weight % of a matrix material derived from a (b) binder material having a glass transition temperature of less than 40° C.; (c) 0.0001-50 weight % of certain additives; (d) less than 5 weight % of water; and (e) at least 0.002 weight % of an opacifying colorant different from all of the (c) additives. Foamable and foamed aqueous compositions can be used to provide these foamed, opacifying elements for use as light-blocking window shades, curtains, or other materials. These light-blocking articles can also have a printable outer surface that accepts ink for making printed images that are not observable from the opposite surface.
1. A foamed, opacifying element comprising:
a substrate having a first opposing surface and a second opposing surface,
a single foamed opacifying layer disposed on the first opposing surface of the substrate, and an outermost nonfoamed functional composition disposed directly on the single foamed opacifying layer, wherein the single foamed opacifying layer comprises:
(a) at least 0.1 weight % and up to and including 80 weight % of nonporous polymeric particles having a porosity of less than 4 volume %, each nonporous polymeric particle having a mode particle size of at least 2 μm and up to and including 50 μm;
(b′) at least 10 weight % and up to and including 80 weight % of a matrix material that is derived from a (b) binder material having a glass transition temperature (T g ) of less than 40° C.;
(c) at least 0.0001 weight % and up to and including 50 weight % of two or more additives, at least one of these two or more additives being a foaming agent and another of these two or more additives being a foam stabilizing agent;
(d) less than 5 weight % of water; and
(e) at least 0.002 weight % of an opacifying colorant different from all of the two or more additives of (c), which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm,
all amounts being based on the total weight of the single foamed opacifying layer, and
the nonfoamed functional composition comprises at least (i) glass particles having an average particle size of at least 5 μm and up to and including 100 μm and a (iv) film-forming organic polymeric binder in an amount of at least 1 weight %, based on the total nonfoamed functional composition weight, in which the (i) glass particles are dispersed,
the nonfoamed functional composition being present at a dry coverage of at least 0.5 g/m 2 and up to and including 10 g/m 2 .
2. The foamed, opacifying element of claim 1 , wherein the (a) nonporous polymeric particles are present in an amount of at least 0.1 weight % and up to and including 40 weight %, based on the total weight of the single foamed opacifying layer.
3. The foamed, opacifying element of claim 1 , wherein the (e) opacifying colorant is carbon black that is present in an amount of at least 0.02 weight % and up to and including 1 weight %, based on the total weight of the single foamed opacifying layer.
4. The foamed, opacifying element of claim 1 , having an optical density (OD) of at least 5.
5. The foamed, opacifying element of claim 1 , wherein the substrate is a woven or nonwoven textile fabric.
6. The foamed, opacifying element of claim 1 , wherein the single foamed opacifying layer is present at a dry coverage of less than or equal to 10 ounces (mass)/yd 2 .
7. The foamed, opacifying element of claim 1 , wherein the nonfoamed functional composition is present at a dry coverage of at least 1 g/m 2 and up to and including 10 g/m 2 .
8. The foamed, opacifying element of claim 1 , wherein the nonfoamed functional composition further comprises one or more of a (ii) solid lubricant, a (iii) tinting material, and a (v) crosslinking agent.
9. The foamed, opacifying element of claim 1 , wherein the (i) glass particles are hollow glass particles that are present in an amount of at least 25 weight % and up to and including 80 weight %, based on the total weight of the nonfoamed functional composition.
10. The foamed, opacifying element of claim 1 , wherein the (iv) film-forming organic polymeric binder is self-crosslinkable or crosslinkable in the presence of a (v) crosslinking agent that is also present in the nonfoamed functional composition.
11. The foamed, opacifying element of claim 1 , wherein the foaming agent and foam stabilizing agent are chosen from ammonium stearate, sodium lauryl sulfate, ammonium lauryl sulfate, ammonium sulfosuccinate, disodium stearyl sulfosuccinate, diammonium n-octadecyl sulfosuccinamate, an ethoxylated alcohol, a fatty acid soap, and a fatty acid condensation product with an alkylene oxide.