Foamable aqueous compositions can be foamed and applied to porous substrates to make light-blocking dry opacifying elements. Such compositions have 0.05-15 weight % of porous particles; at least 20 weight % of a binder; at least 0.0001 weight % of additives (including a surfactant); water; and at least 0.001 weight % of an opacifying colorant. Each porous particle includes a continuous polymeric phase and discrete pores; a mode particle size of 2-50 m; and a porosity of 20-70 volume %. The continuous polymeric phase T.sub.g is >80 C. and has a polymer viscosity of 80-500 centipoises at an ethyl acetate shear rate of 100 sec.sup.1 at a concentration of 20 weight % at 25 C. The dry opacifying element light blocking value is at least 4 and has a luminous reflectance >40% as measured by the Y tristimulus value. The foamed aqueous composition has a foam density of 0.1-0.5 g/cm.sup.3.

A foamed, opacifying element has a thermal colorant image on either an opposing external surface and an internal surface of a porous substrate. The internal surface has a dry foamed composition disposed thereon as a dry opacifying layer that comprises: (a) 0.1-40 weight % of porous particles; (b) at least 10 weight % of an at least partially cured binder material; (c) at least 0.2 weight % of one or more additives comprising a surfactant; (d) less than 5 weight % of water; and (e) at least 0.002 weight % of an opacifying colorant different from all of the one or more (c) additives, which opacifying colorant absorbs predetermined electromagnetic radiation. The thermal colorant image is derived from thermal colorant transfer of sublimable colorants from a thermal donor element.

A foamed, opacifying element has a thermal colorant image on either an opposing external surface and an internal surface of a porous substrate. The internal surface has a dry foamed composition disposed thereon as a dry opacifying layer that comprises: (a) 0.1-40 weight % of porous particles; (b) at least 10 weight % of an at least partially cured binder material; (c) at least 0.2 weight % of one or more additives comprising a surfactant; (d) less than 5 weight % of water; and (e) at least 0.002 weight % of an opacifying colorant different from all of the one or more (c) additives, which opacifying colorant absorbs predetermined electromagnetic radiation. The thermal colorant image is derived from thermal colorant transfer of sublimable colorants from a thermal donor element.

Foamed, opacifying element comprising a thermal colorant image is prepared using a porous substrate having an opposing external surface and an internal surface, and a dry foamed composition disposed on the internal surface of the porous substrate as a dry opacifying layer that has a light blocking value of at least 4 as well as a luminous reflectance that is greater than 40% as measured by the Y tristimulus value. A thermal colorant image is provided on either the opposing external surface, the dry opacifying layer, or both the opposing external surface and the dry opacifying layer, by thermal colorant transfer from a thermal donor element comprising a colorant donor layer having one or more thermal colorants.

Provided is a process for producing a coating on a substrate comprising one or more steps of crushing a dried layer of a foamed aqueous coating composition, wherein the aqueous coating composition comprises a collection of multi-stage copolymer particles having a weight average diameter of 2-20 m, wherein said multi-stage copolymer particles comprise a core having a glass transition temperature (Tg) of 20 C. or less. Also provided is a coated substrate made by that process.

A foamed, opacifying element has a porous substrate composed of woven yarn strands composed of a thermoplastic polymer-coated multifilament core. It has a dry foamed composition on an opposing surface of the substrate, which includes: (a) 0.1-40 weight % of porous particles; (b) 10-80 weight %; (c) 0.2-50 weight % of one or more additives selected from the group consisting of dispersants, plasticizers, flame retardants, optical brighteners, thickeners, biocides, fungicides, tinting colorants, metal flakes, and inert inorganic or organic fillers; (d) less than 5 weight % of water; and (e) at least 0.002 weight % of an opacifying colorant different from all of the one or more additives of (c), which opacifying colorant absorbs electromagnetic radiation having a wavelength of 380-800 nm. The elements have a light-blocking value (LBV) of at least 4 and can have a bending stiffness that is greater than 0.15 milliNewtons-meter.

A light-blocking article is designed to be lightweight but effective to block most incident actinic radiation and can be designed into fabrics, curtains, and other materials. Such an article has an opacifying layer that is capable of blocking predetermined electromagnetic radiation. The article contains (a) porous particles comprising a continuous polymeric binder and pores within the continuous polymeric binder, the porous particles having a glass transition temperature of at least 25 C. and a mode particle size of at least 2 m and up to and including 50 m. The article also contains an opacifying colorant that absorbs the predetermined electromagnetic radiation (such as within 400 nm to 700 nm), in an amount of at least 0.001 weight % based on the total dry weight of the opacifying layer, and a matrix polymer in which the porous particles and opacifying colorant are dispersed.

A method for providing a foamed, opacifying element includes providing a foamable aqueous composition, aerating it to a foam density of 0.1-0.5 g/cm.sup.3, applying the foamed aqueous composition to a porous substrate, drying, and densifying the dried layer. Such foamable aqueous compositions have 0.05-15 weight % of porous particles; at least 20 weight % of a binder; at least 0.0001 weight % of additives (including a surfactant); water; and at least 0.001 weight % of an opacifying colorant. Each porous particle includes a continuous polymeric phase and discrete pores; a mode particle size of 2-50 m; and a porosity of 20-70 volume %. The continuous polymeric phase T.sub.g is >80 C. and has a polymer viscosity of 80-500 centipoises at an ethyl acetate shear rate of 100 sec.sup.1 at a concentration of 20 weight % at 25 C.

A foamed, opacifying element having a target light blocking value (LBV.sub.T) and a target porous substrate is prepared by determining the light blocking value (LBV.sub.S) of the target porous substrate; calculating the LBV.sub.T-S difference; choosing a foamable aqueous composition; determining a dry coating weight for the chosen foamable aqueous composition (when foamed); and using the dry coating weight to form the single dry opacifying layer as the only layer disposed on the target porous substrate, such that the single dry opacifying layer has light blocking value that is equal to LBV.sub.T-S, 10%. The chosen foamable aqueous composition comprises the essential components (a) through (e) described herein. The desired foamable aqueous composition can be chosen from a set of similar compositions to achieve the desired LBV.sub.T with the noted target porous substrate using suitable mathematical formula relating dry coating weight to light blocking value and a suitable data processor.

A method for providing a foamed, opacifying element includes providing a foamable aqueous compositions, aerating it to a foam density of 0.1-0.5 g/cm.sup.3, applying the foamed aqueous composition to a porous substrate, drying, and densifying the dried layer Such foamable aqueous compositions have 0.05-15 weight % of porous particles; at least 20 weight % of a binder; at least 0.0001 weight % of additives (including a surfactant); water; and at least 0.001 weight % of an opacifying colorant. Each porous particle includes a continuous polymeric phase and discrete pores; a mode particle size of 2-50 m; and a porosity of 20-70 volume %. The continuous polymeric phase T.sub.g is>80 C. and has a polymer viscosity of 80-500 centipoises at an ethyl acetate shear rate of 100 sec.sup.1 at a concentration of 20 weight % at 25 C.