In-flight encapsulation of particles

A process for the in situ encapsulation of particles between a spraying apparatus and an earth target, comprising the steps of:

• preparing a self-encapsulating polymeric-containing solution;
• said solution comprising by weight from about 0.3 percent to about 25 percent of a polymer, from about 35 percent to about 99 percent of a solvent, said solvent being a compound which will solubilize said polymer, and from about 1 percent to about 40 percent of the particles, said particle being soluble or dispersible in said solvent;
• said polymer selected from the class consisting of (a) polyvinyl acetate;
• (b) a polyvinyl ether within said repeating unit has from 2 to 10 carbon atoms;
• (c) an acrylic polymer or a copolymer made from monomers having the formula ##STR14## wherein R.sub.4 is hydrogen or an alkyl, cycloalkyl, aryl, or aralkyl having from 1 to 30 carbon atoms and R.sub.5 is hydrogen or an alkyl, cycloalkyl, aryl, or aralkyl having from 1 to 12 carbon atoms;
• (d) the salt of (1) an interpolymer having the structure ##STR15## wherein R and R.sub.1 are members of the group consisting of hydrogen and methyl;
• R.sub.2 is a member of the group consisting of methyl, ethyl, propyl and butyl;
• R.sub.3 is a member of the group consisting of methyl and ethyl;
• n represents from 3 to 12 weight percent based on the combined weight of n, x, y and z;
• x represents from 8 to 25 percent based on the combined weight of n, x, y and z;
• y represents from 45 to 89 weight percent based on the combined weight of n, x, y and z;
• z represents from 0 to 44 weight percent based on the combined weight of n, x, y and z;
• the sum of the numerical value of n+x+y+z is always exactly 100 and the groups n, x, y and z are present in a heterogeneous relative position, and (2) a member of the group consisting of ammonia, hydrazine, a low boiling primary aliphatic amine and a low boiling secondary aliphatic amine, said salt being soluble in water in the pH range of from about 5 to 8;
• and (e) combinations thereof;
• in situ encapsulating said soluble or dispersible particle by:
• spraying into the earth's atmosphere said solution containing said soluble or dispersible particle from a spray apparatus, and immediately thereafter;
• evaporating said solvent in aid earth's atmosphere, and
• coacervating during the passage from said spraying apparatus to an earth target said polymer and said particle in said earth's atmosphere so that said polymer substantially encapsulates said particle, and
• concurrently and directly applying said encapsulated particle to an earth target.

An in situ self-encapsulating polymericcontaining solution for concurrent and direct application to an earth target, comprising by weight, based upon the total weight of said solution

• from about 0.3 percent to about 25 percent of a polymer, from about 35 percent to about 99 percent of a solvent, and from about 1 percent to about 40 percent of a particle,
• said polymer selected from the group consisting of (a) a polyvinyl acetate, (b) a polyvinyl ether wherein said repeating unit has from 3 to 10 carbon atoms, (c) an acrylic polymer or a copolymer made from monomers having the formula ##STR20## where R.sub.4 is hydrogen or an alkyl, cycloalkyl, aryl, or aralkyl having from 1 to 30 carbon atoms and R.sub.5 is hydrogen or an alkyl, cycloalkyl, aryl, or aralkyl having from 1 to 12 carbon atoms;
• (d) the salt of (1) an interpolymer having the structure ##STR21## wherein R and R.sub.1 are members of the group consisting of hydrogen and methyl;
• R.sub.2 is a member of the group consisting of methyl, ethyl, propyl and butyl;
• R.sub.3 is a member of the group consisting of methyl and ethyl;
• n represents from 3 to 12 weight percent based on the combined weight of n, x, y and z;
• x represents from 8 to 25 percent based on the combined weight of n, x, y and z;
• y represents from 45 to 89 weight percent based on the combined weight of n, x, y and z;
• z represents from 0 to 44 weight percent based on the combined weight of n, x, y and z;
• the sum of the numerical value of n+x+y+z is always exactly 100 and the groups n, x, y and z are present in a heterogeneous relative position, and (2) a member of the group consisting of ammonia, hydrazine, a low boiling primary aliphatic amine and a low boiling secondary aliphatic amine, said salt being soluble in water in the pH range of from about 5 to 8;
• and (e) combinations thereof;
• said particle being soluble or dispersible in said solvent;
• said solvent being a compound in which said polymer is soluble;
• and
• a small amount of weight based upon the total weight of the solution of an adhesive agent so that upon the in situ formation of an encapsulated particle from said solution and the concurrent and direct application of said encapsulated particle to an earth target, said adhesive agent improves the tackiness of said encapsulated particle to said target.