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US4302254A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for the manufacture of pigment preparations

Assignee: Hoechst AG
•
Filing: 1980-03-17
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Granted: 1981-11-24
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Expires: 2000-03-17
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Abstract

Abstract An easy method for preparing pigment preparations on wax basis in an aqueous medium is treating the pigment in the aqueous medium with a solution of the wax in an organic solvent. The so-obtained preparations are easily dispersible in lacquers and plastic masses and allow to obtain the full tinctorial strength of the pigment without needing much energy for dispersing the pigment in the substrate.

Inventors

  • 👤 Josef Landler

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 17:28
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/22; C08J3/226; C09; C09B; C09B67/00; C09B67/0071; C09B67/0092; C09B67/0095; C08J2491/00

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 134 words
A method of preparing a pigment composition having improved dispersibility, which comprises vigorously agitating an aqueous dispersion of a pigment precursor selected from the group consisting of the potassium hydroxide addition and sodium hydroxide addition compounds of naphthoylene-bis-benzimidazole, converting said pigment precursor to a pigment in said dispersion, mixing an organic solvent solution of a wax, the amount of wax being such that its weight in the pigment composition prepared is 5 to 10% of the weight of the dry pigment, with said dispersion before or during the formation of said pigment, thermally treating the waxed pigment particles in the dispersion at a temperature of from 40° to 140° C., isolating the waxed pigment from the dispersion, freeing the waxed pigment from adhering solvent and aqueous medium, and drying and grinding the waxed pigment.
Claim 2
Independent Claim 134 words
A method of preparing a pigment composition having improved dispersibility, which comprises vigorously agitating an aqueous dispersion of a pigment precursor selected from the group consisting of the potassium hydroxide addition and sodium hydroxide addition compounds of naphthoylene-bis-benzimidazole, converting said pigment precursor to a pigment in said dispersion, mixing an organic solvent solution of a wax, the amount of wax being such that its weight in the pigment composition prepared is 5 to 10% of the weight of the dry pigment, with said dispersion before or during the formation of said pigment, thermally treating the waxed pigment particles in the dispersion at a temperature of from 40° to 140° C., isolating the waxed pigment from the dispersion, freeing the waxed pigment from adhering solvent and aqueous medium, and drying and grinding the waxed pigment.
Claim 3
Dependent Claim 14 words
A method as claimed in claim 1, wherein the aqueous medium contains an emulsifier.
Claim 4
Dependent Claim 18 words
A method as claimed in claim 1, wherein the wax is a polyethylene wax, a paraffin or beeswax.
Claim 5
Dependent Claim 10 words
A pigment preparation made by the method of claim 1.

References Cited (Backward Citations)

US1651733A Cited
US3577489A Cited
US3856699A Cited
US3755244A Cited
US3808019A Cited
US3773535A Cited
US4055439A Cited
US4235641A Cited
US4158571A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-11-23 1985-05-25 1985-11-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-11-23 1989-05-25 1989-11-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-11-23 1993-05-25 1993-11-24 $7700.00 Window Closed / Lapsed

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