Metal-joining paste and vehicle therefor

Claim 2

A vehicle for a metal-joining paste composition comprising in weight parts: 0.1-10 parts hydroxypropyl cellulose, the concentration of said hydroxypropyl cellulose being sufficient for imparting initial apparent viscosity between about 5,000 and about 50,000 centipoises to said vehicle; - 20parts selected from the group consisting of glycerine, water, and mixtures thereof; 0-50 parts of fluxing agent; 0-3 parts surfactant; and 55-99 parts of a mixture of polyalkoxyalkanols, said composition being a solvent for its hydroxypropyl cellulose content at 50° C.

Claim 3

The vehicle of claim 1 wherein said mixture of polyalkoxyalkanols comprises dipropylene glycol methyl ether and diethylene glycol butyl ether.

Claim 4

The vehicle of claim 1 wherein said mixture of polyalkoxyalkanols comprises dipropylene glycol methyl ether and diethylene glycol hexyl ether.

Claim 5

The vehicle of claim 2 wherein the ratio of said dipropylene glycol methyl ether to diethylene glycol butyl ether is between about 1:1 and about 8:1.

Claim 6

The vehicle of claim 1 wherein said surfactant is a fluorosurfactant.

Claim 7

The vehicle of claim 1 wherein said vehicle is anhydrous.

Claim 8

The vehicle of claim 1 containing 0.5-5 parts hydroxypropyl cellulose.

Claim 9

A metal-joining paste composition comprising in parts by weight: 50 to 95 parts metal powder, and 5 to 50 parts vehicle, wherein said metal powder has a particle size of less than 295 microns and said vehicle comprises: 0.1-10 parts hydroxypropyl cellulose, the concentration of said hydroxypropyl cellulose being sufficient for imparting initial apparent viscosity between about 5,000 and about 50,000 centipoises to said vehicle, 1-20 parts selected from the group consisting of glycerine, water, and mixtures thereof, 0-50 parts fluxing agent, 0-3 parts surfactant, and 55 to 99 parts a mixture of polyalkoxyalkanols, said vehicle composition being a solvent for its hydroxypropyl cellulose content at 50° C.

Claim 10

A metal-joining paste composition comprising in parts by weight: 50 to 95 parts metal powder, and 5 to 50 parts vehicle, wherein said metal powder has a particle size of less than 295 microns and said vehicle comprises: 0.1-10 parts hydroxypropyl cellulose, the concentration of said hydroxypropyl cellulose being sufficient for imparting initial apparent viscosity between about 5,000 and about 50,000 centipoises to said vehicle, 1-20 parts selected from the group consisting of glycerine, water, and mixtures thereof, 0-50 parts fluxing agent, 0-3 parts surfactant, and 55 to 99 parts a mixture of polyalkoxyalkanols, said vehicle composition being a solvent for its hydroxypropyl cellulose content at 50° C.

Claim 11

The metal-joining paste of claim 8 wherein said mixture of polyalkoxyalkanols comprises diethylene glycol butyl ether and dipropylene glycol methyl ether.

Claim 12

The metal-joining paste of claim 8 wherein said mixture of polyalkoxyalkanols comprises dipropylene glycol methyl ether and diethylene glycol hexyl ether.

Claim 13

The metal-joining paste of claim 9 wherein the ratio of said diethylene glycol butyl ether to dipropylene glycol methyl ether is between about 1:1 and 8:1.

Claim 14

The metal-joining paste of claim 8 wherein said surfactant is a fluorosurfactant.

Claim 15

The metal-joining paste of claim 8 wherein said vehicle is anhydrous.

Claim 16

The metal-joining paste of claim 8 which contains 0.5-5 parts hydroxypropyl cellulose.

Claim 17

In a brazing or soldering operation using a metal-joining paste with a vehicle the improvement comprising using as said vehicle a composition which comprises in weight parts: 0.1-10 parts hydroxypropyl cellulose, the concentration of said hydroxypropyl cellulose being sufficient for imparting initial apparent viscosity between about 5,000 and about 50,000 centipoises to said vehicle, 1-20 parts selected from the group consisting of glycerine, water, and mixtures thereof, 0-50 parts fluxing agent, 0-3 parts surfactant, and 55 to 99 parts of a mixture of polyalkoxyalkanols, said vehicle composition being a solvent for its hydroxypropyl cellulose content at 50° C.

Claim 18

In a brazing or soldering operation using a metal-joining paste with a vehicle the improvement comprising using as said vehicle a composition which comprises in weight parts: 0.1-10 parts hydroxypropyl cellulose, the concentration of said hydroxypropyl cellulose being sufficient for imparting initial apparent viscosity between about 5,000 and about 50,000 centipoises to said vehicle, 1-20 parts selected from the group consisting of glycerine, water, and mixtures thereof, 0-50 parts fluxing agent, 0-3 parts surfactant, and 55 to 99 parts of a mixture of polyalkoxyalkanols, said vehicle composition being a solvent for its hydroxypropyl cellulose content at 50° C.