公开(公告)号：US3388120A

公开(公告)日：1968-06-11

申请号：US59674666

申请日：1966-11-25

Applicant: STALEY MFG CO A E

Inventor： LOTZGESELL JAMES A ,  BEST ROLAND W

IPC: D21H19/10 ,  C08B31/00 ,  C08B31/16 ,  D21H17/28 ,  D21H19/54

CPC classification number: D21H17/28 ,  C08B31/00 ,  C08B31/16 ,  D21H19/54

公开(公告)号：US3876629A

公开(公告)日：1975-04-08

申请号：US46408474

申请日：1974-04-25

Applicant: STALEY MFG CO A E

Inventor： LOTZGESELL JAMES A

IPC: B41M5/124 ,  B41M7/02 ,  C08B31/00 ,  C09D11/00 ,  C08B19/06

CPC classification number: C09D11/00 ,  B41M5/1243 ,  B41M7/02 ,  C08B31/003

Abstract: Starch in granule form, more particularly large cereal starch granules obtained from hydrocyclone separation of a prime grade wheat starch slurry, are crosslinked with phosphorus oxychloride under highly alkaline conditions in an aqueous suspension to raise the gelatinization temperature of the starch granules. The crosslinked starch granules so obtained have substantially improved heat stability, and can be used in carbonless paper coating processes which operate at a temperature up to about 160.degree.F., which is more than 20.degree.F. higher than the normal gelatinizing temperature of the untreated starch, but lower than the gelatinizing temperature of the crosslinked starch granules. The crosslinking reaction is commenced slowly with an initial controlled addition of phosphorus oxychloride at a pH of at least 11.5 and at a high titer which is increased substantially during the reaction by the controlled simultaneous addition of sodium hydroxide and phosphorus oxychloride. No added gelatinization inhibitors are required because the initial crosslinking stabilizes the starch and inhibits gelatinization. The treated large granules range in size from 12 to 40 microns, and the initial pasting temperature is raised from about 135.degree.F. to about 162.degree.F. which is completely adequate for the paper coating process described. The crosslinking method here described can also be used to increase the pasting temperature of other starches, including corn, waxy maize, sorghum, rice, rye, barley, potato, tapioca or sago starch. Rye and barley, in particular, can also be size classified by means of hydrocyclone separation so that the crosslinked, large granule, temperature stable product so obtained can be used in carbonless paper coatings to replace the much more scarce arrowroot starch granules formerly used.