Selective gas phase filter material

Abstract

An improved tobacco smoke filter material is formed from a porous particulate carrier impregnated with an additive having an affinity for volatile smoke acids and aldehydes, such as buffered polyethyleneimine, wherein the carrier particles have a pore diameter from 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram, and a pore volume no less than about 0.3 cubic centimeter per gram.

Having thus described my invention, what is claimed is: 
     
       1. An improved tobacco smoke filter material comprising .[.at least 100 mg. of.]. a porous particulate carrier impregnated with a poly(alkyleneimine) alkanoate, wherein from about 2 to 6 percent by weight alkanoate is deposited on the carrier based on the total weight of the alkanoate and carrier, said poly(alkyleneimine) alkanoate having a pH from about 6.0 to 7.6, and wherein each of said carrier particles has a pore diameter of from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic centimeter per gram. .[.2. The invention in accordance with claim 1 in which the 
     
     
        carrier is a porous alumina..]. 3. The tobacco smoke filter .Iadd.material .Iaddend.of claim 1 wherein the pH of the poly(alkyleneimine) is buffered 
     
     
        to about 7.4 with acetic acid. 4. An improved filter adapted to be affixed to a cigarette and comprising, in combination: a filter outer wrap having a tubular configuration and an inner filler formed from a plurality of particles formed from a porous particulate carrier impregnated with an alkanoic acid buffered poly(alkyleneimine) additive, said additive buffered to a pH from about 6.0 to 7.6, from about 2 to 6 percent by weight additive deposited on the carrier based on the total weight of carrier and additive, wherein from about 100 to 150 milligrams of filler are employed in said filter and wherein the carrier particles each have a pore diameter from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 
     
     
        cubic centimeter per gram. 5. An improved tobacco smoke filter material comprising .[.at least 100 mg. of.]. a porous particulate carrier impregnated with a poly(alkyleneimine) buffered with an alkanoic acid to a pH from about 6.0 to 7.6, wherein from about 2 to 6 percent by weight buffered poly(alkyleneimine) is deposited on the carrier based on the total weight of the buffered poly(alkyleneimine) and carrier and wherein the carrier particles each have a pore diameter from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a 
     
     
        pore volume no less than about 0.3 cubic centimeter per gram. 6. An improved tobacco smoke filter .[.material.]. adapted to be affixed to a cigarette and comprising: at least 100 milligrams of a porous alumina impregnated with poly(ethyleneimine) buffered to a pH of 7.4 with acetic acid, wherein the porous alumina has a pore diameter of from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram, a pore volume of from 0.3 to 0.8 cubic centimeter per gram and wherein from about 4 to 6 percent by weight buffered poly(ethyleneimine) is 
     
     
        deposited on the porous alumina. 7. An improved filter adapted to be affixed to a cigarette and comprising, in combination: a filter outer wrap having a tubular configuration and an inner filler formed from a plurality of particles formed from at least 100 milligrams of a porous particulate carrier impregnated with a poly(alkyleneimine) buffered with an alkanoic acid wherein from about 2 to 6 percent by weight acid buffered poly(alkyleneimine) is deposited on the carrier base on the total weight of the poly(alkyleneimine) and carrier, said poly(alkyleneimine) being buffered to a pH from about 6.0 to 7.6 and having an affinity for volatile smoke aldehydes and acids, wherein the carrier particles each have a pore diameter from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic 
     
     
        centimeter per gram. 8. The invention in accordance with claim 7 in which 
     
     
        the carrier is a porous alumina. 9. The invention in accordance with claim 8 wherein the additive is poly(ethyleneimine) buffered to a pH of about 7.4 with acetic acid and wherein from 4 to 6 percent by weight of poly(ethyleneimine) is deposited on the porous alumina. .Iadd. 10. An improved tobacco smoke filter material comprising a porous particulate alumina carrier impregnated with a poly(alkyleneimine) buffered with an alkanoic acid to a pH from about 6.0 to 7.6, wherein from about 2 to 6 percent by weight buffered poly(alkyleneimine) is deposited on the carrier based on the total weight of the buffered poly(alkyleneimine) and carrier and wherein the carrier particles each have a pore diameter from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic centimeter per gram. .Iaddend. .Iadd. 11. An improved tobacco smoke filter material comprising a porous particulate alumina carrier impregnated with a poly(alkyleneimine)alkanoate, wherein from about 2 to 6 percent by weight alkanoate is deposited on the carrier based on the total weight of the alkanoate and carrier, said poly(alkyleneimine) alkanoate having a pH from about 6.0 to 7.6, and wherein each of said carrier particles has a pore diameter of from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic centimeter per gram. .Iaddend..Iadd. 12. An improved tobacco smoke filter material comprising a porous particulate alumina carrier impregnated with a poly(alkyleneimine) acetate wherein from about 2 to 6 percent by weight acetate is deposited on the carrier based on the total weight of the acetate and carrier, said poly(alkyleneimine) acetate having a pH from about 6.0 to 7.6, and wherein each of said carrier particles has a pore diameter of from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic centimeter per gram. .Iaddend..Iadd. 13. An improved tobacco smoke filter material comprising a porous particulate alumina carrier impregnated with a poly(alkyleneimine) buffered with an acetic acid to a pH from about 6.0 to 7.6, wherein from about 2 to 6 percent by weight buffered poly(alkyleneimine) is deposited on the carrier based on the total weight of the buffered poly(alkyleneimine) and carrier and wherein the carrier particles each have a pore diameter from about 0.1 to 2.0 microns, a surface area of from about 1 to 15 square meters per gram and a pore volume no less than about 0.3 cubic centimeter per gram. .Iaddend.