Pierce & Stevens Corporation

Other

George E Melber

Leon E Wolinski

William A Oswald

Microsphere beads are mixed with a surface barrier liquid or mixture of such a liquid with a solid effective to prevent agglomeration and surface bonding of the microspheres; by the control of the application of heat and balancing temperature and active mixing, removal of water from the microspheres is achieved. The surface barrier liquid or mixture of such a liquid with a solid in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, plasticizers, diluents, extenders, monomers and oligomers, and the like.

Process for drying microspheres

Microsphere wet cake is mixed with a surface barrier coating effective to prevent agglomeration and surface bonding of the microspheres, and removing water by drying with continuous mixing at high shear. In a subsequent step, by the control of the application of heat and balancing temperature and low shear mixing, it is possible to also control expansion of the microspheres. The surface barrier coating in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, dry inorganic pigments or filler materials, and the like, and related organic materials.

Thermoplastic microspheres

Process for making dry microspheres

In the present invention, polymer binder systems are filled with inert fillers, such as calcium carbonate, and with specific thermoplastic microspheres bearing a surface coating of an inert particulate material compatible with the polymer binder system. The preferred inert particulate material on the microspheres is particulate or fibrous forms of calcium carbonate. The microspheres have a very low density, and the inert particulate for fibrous coating is thermally bonded to surface thereof. The microspheres may be employed in proportions up to as much as about 70 volume percent of the casting or molding composition, resulting in a product of exceptionally low weight and density. The products of the present invention also provide high impact strength, high resistance to cracking and crack propagation, high tensile and yield strength, and a high modulus of elasticity, particularly compared to the usual cast marble products known to the art.

Simulated marble products

Enhanced hiding power for opacifiers in paints, inks, and other coatings is provided by employing the opacifiers, such as TiO.sub.2, ZnO, talc, CaCo.sub.3, and the like, adhered to or embedded in the surface of thermoplastic microspheres. The composite opacifier-microsphere material is readily formed with a preselected specific gravity, so that there is little tendency for the material to separate. In addition, the composite behaves in the coating as a opacifier-air interface, having a very high difference in refractive indices, and exceptional hiding power. The high volume to weight ratio of the composite affords very attractive economic advantages, effectively reducing the weight proportion of opacifiers required in the formulations, and other related advantages.

Coating media containing low density composite opacifiers

Preparation of opacifier intermediates

Opacifiers for paints and coatings

Syntactic foam graphic arts print media are provided which are particularly suitable for application to a substrate using high speed mechanical printing processes. The invention involves adding to a basic print medium a minor amount of pre-expanded, nonfriable, thermoplastic polyvinylidene chloride based microspheres substantially heat stable between about -20.degree. C. and 175.degree. C., having a particle size to about 10 to 100 microns in diameter, to produce syntactic foams having unlimited shelflife stability. The print media thereby produced may be applied to any known substrate in any desired graphic pattern.

Expandable graphic art printing media using a syntactic foam based on

Film forming binders containing low density composite opacifiers

Enhanced hiding power for opacifiers in paints, inks, and other coatings is provided by employing the opacifiers, such as TiO.sub.2, ZnO, talc, CaCO.sub.3, and the like, adhered to or embedded in the surface of thermoplastic microspheres. The composite opacifier-microsphere material is readily formed with a preselected specific gravity, so that there is little tendency for the material to separate. In addition, the composite behaves in the coating as a opacifier-air interface, having a very high different in refractive indices, and exceptional hiding power. The high volume to weight ratio of the composite affords very attractive economic advantages, effectively reducing the weight proportion of opacifiers required in the formulations, and other related advantages.

Methods for preparing opaque coatings and applying the same

Enhanced hiding power for opacifiers in paints, inks, and other coatings is provided by employing the opacifiers, such as TiO.sub.2, ZnO, talc, CaCo.sub.3, and the like, adhered to or embedded in the surface of thermoplastic micorspheres. The composite opacifier-microsphere material is readily formed with a preselected specific gravity, so that there is little tendency for the material to separate. In addition, the composite behaves in the coating as a opacifier-air interface, having a very high difference in refractive indices, and exceptional hiding power. The high volume to weight ratio of the composite affords very attractive economic advantages, effectively reducing the weight proportion of opacifiers required in the formulations, and other related advantages.

Low density composite opacifiers

Microsphere wet cake is mixed with a processing aid efective to prevent agglomeration and surface bonding of the microspheres, and thereafter removing water by drying with continuous mixing, optionally also under reduced pressure, i.e. vacuum drying. By the control of the application of heat and balancing temperature and the mixing, and optionally also the reduced pressure, it is possible to also control expansion of the microspheres from substantially none to substantially theoretical limits of expansion. The processing aid in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, dry inorganic pigments or filler materials, and the like, and related organic materials.

Syntactic polymer foam compositions containing microsphere fillers

Microsphere wet cake is mixed with a processing aid effective to prevent agglomeration and surface bonding of the microspheres, and thereafter removing water by drying with continuous mixing, optionally also under reduced pressure, i.e. vacuum drying. By the control of the application of heat and balancing temperature and the mixing, and optionally also the reduced pressure, it is possible to also control expansion of the microspheres from substantially none to substantially theoretical limits of expansion. The processing aid in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e. to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, dry inorganic pigments or filler materials, and the like, and related organic materials.

Syntactic foam graphic arts print media are provided which are particularly suitable for application to a substrate using high speed mechanical printing processes. The invention involves adding to a basic print medium a minor amount of pre-expanded, nonfriable, thermoplastic polyvinylidene chloride based microspheres substantially heat stable between about -20.degree. C. and 175.degree. C., having a particle size of about 10 to 100 microns in diameter, to produce syntactic foams having unlimited shelflife stability. The print media thereby produced may be applied to any known substrate in any desired graphic pattern.

Graphic art printing media using a syntactic foam based on expanded

Microsphere wet cake is mixed with a processing aid effective to prevent agglomeration and surface bonding of the microspheres, and thereafter removing water by drying with continuous mixing, optionally also under reduced pressure, i.e. vacuum drying. By the control of the application of heat and balancing temperature and the mixing, and optionally also the reduced pressure, it is possible to also control expansion of the microspheres from substantially none to substantially theoretical limits of expansion. The processing aid in the present invention is any one of a wide diversity of materials which meet the requirements of the intended function, i.e., to prevent the agglomeration of the microspheres during the process. Suitable materials include, by way of example, dry inorganic pigments or filler materials, and the like, and related organic materials.

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Depew, NY, United States of America

George E Melber