Abstract This invention relates to the production of dispersing agents from mixtures of spent sulphite liquor solids and Kraft liquor solids. Although appropriate physical mixtures of said solids without further treatment have useful dispersant characteristics for specific applications, the preferred way of preparing improved dispersant compositions from mixtures of said solids consists in heat treating concentrated aqueous solutions thereof for 1 to 3 hours at 100* to 160*C, at pH values higher than 11.0. The heat treatment is preferably performed under simultaneous blowing of air through the reaction mixture. The addition of a crosslinking agent, such as formaldehyde, is optional in cases where the air blowing treatment is not employed during the heat treatment. The dispersing agents of this invention have utility as dye dispersants, carbon black dispersants, clay dispersants, and the like.
A composition as defined in claim 1, wherein unfractionated Kraft liquor solids comprise from about 15 to about 85 percent of the blend, on a solids weight basis, and unfractionated spent sulphite liquor solids comprise the remainder.
Claim 2
Dependent Claim
29 words
A composition as defined in claim 1, wherein high molecular weight Kraft lignins comprise from about 10 to about 75 percent of the blend on a solids weight basis.
Claim 3
Dependent Claim
75 words
A dispersant composition consisting essentially of a blend of Kraft liquor solids cross-linked with spent sulphite liquor solids, said solids being selected from the group consisting of the unfractionated liquor solids and the high molecular weight fractions thereof and said Kraft liquor solids comprising from about 10 to about 85 percent of said blend, on a solids weight basis, with said sulphite liquor solids comprising the remainder, in the form of a concentrated aqueous solution.
Claim 4
Dependent Claim
75 words
A dispersant composition consisting essentially of a blend of Kraft liquor solids cross-linked with spent sulphite liquor solids, said solids being selected from the group consisting of the unfractionated liquor solids and the high molecular weight fractions thereof and said Kraft liquor solids comprising from about 10 to about 85 percent of said blend, on a solids weight basis, with said sulphite liquor solids comprising the remainder, in the form of a spray dried powder.
Claim 5
Dependent Claim
90 words
A PROCESS FOR IMPROVING THE DISPERSANT PROPERTIES OF A BLEND OF (1) FROM ABOUT 10 TO ABOUT 85 PERCET KRAFT LIQUOR SOLIDS, ON A SOLIDS WEIGHT BASIS, AND (2) SPENT SULPHITE LIQUOR SOLIDS COMPRISING THE REMAINDER, BOTH SAID SOLIDS BEING SELECTED FROM THE GROUP CONSISTING OF THE UNFRACTIONED LIQUOR SOLIDS AND HIGH MOLECULAR WEIGHT FRACTIONS THEREOF, WHICH COMPRISES SUBJECTING SAID BLEND IN A 25 TO 50 PERCENT W/V AQUEOUS SOLUTION TO HEAT TREATMENT AT A TEMPERATURE IN THE RANGE OF ABOUT 115*C TO 160*C FOR FROM 1 TO 3 HOURS.
Claim 6
Dependent Claim
17 words
The process defined in claim 6, wherein said heat treatment is carried out under simultaneous air blowing.
Claim 7
Dependent Claim
22 words
The process defined in claim 6, wherein said solution additionally contains up to about 1.0 percent formaldehyde on a solids weight basis.