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US4094808A Expired / Lapsed US ⏱️ 0.0 years remaining

Solubility stable encapsulated diperisophthalic acid compositions

Assignee: PPG Industries Inc
•
Filing: 1977-04-19
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Granted: 1978-06-13
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Expires: 1997-04-19
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Abstract

Abstract Disclosed is a solubility stable bleaching formulation in the form of an encapsulated core. The core comprises particles of tabular habit diperisophthalic acid (DPI) in admixture with particles of inorganic salt substantially more water-soluble than the diperisophthalic acid. The bleaching formulation maintains a high rate of solution in water after storage under conditions of temperature fluctuation.

Inventors

  • 👤 Dorothy A. Stewart
  • 👤 Bobby D. Ricketts
  • 👤 Charles H. Hoelscher

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 09:39
CPC Classifications
C; C11; C11D; C11D3/00; C11D3/39; C11D3/3945; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 132 words
A bleaching formulation in the form of an encapsulated core wherein the core comprises particles consisting essentially of tabular habit diperisophthalic acid in admixture with from 1.0 to 90 weight percent of an ionic dispersing agent selected from the group consisting of hydratable inorganic salts, non-hydratable inorganic salts and organic acids said agent having a water solubility of 4 to 200 grams per 100 grams of water at 15° C. and whose water solutions have a pH below 9, said core having its diperisophthalic acid content present as tabular habit diperisophthalic acid at the time the bleaching formulation is formed and being essentially completely encapsulated with a water dispersible encapsulating material capable, in the absence of free water, of preventing contact of the diperisophthalic acid with substances capable of causing its decomposition.
Claim 2
Dependent Claim 132 words
A bleaching formulation in the form of an encapsulated core wherein the core comprises particles consisting essentially of tabular habit diperisophthalic acid in admixture with from 1.0 to 90 weight percent of an ionic dispersing agent selected from the group consisting of hydratable inorganic salts, non-hydratable inorganic salts and organic acids said agent having a water solubility of 4 to 200 grams per 100 grams of water at 15° C. and whose water solutions have a pH below 9, said core having its diperisophthalic acid content present as tabular habit diperisophthalic acid at the time the bleaching formulation is formed and being essentially completely encapsulated with a water dispersible encapsulating material capable, in the absence of free water, of preventing contact of the diperisophthalic acid with substances capable of causing its decomposition.
Claim 3
Dependent Claim 39 words
The formulation of claim 1 wherein the dispersing agent, encapsulation material or both is one or more of MgSO 4 , Na 2 SO 4 , or Na 2 Mg(SO 4 ) 2 in their hydrated or unhydrated forms.
Claim 4
Dependent Claim 26 words
The formulation of claim 1 wherein the encapsulated core is essentially spherical and has a diameter in the range of from about 0.1 to 5 millimeters.
Claim 5
Dependent Claim 14 words
The formulation of claim 1 wherein the dispersible encapsulating material is a hydratable salt.

References Cited (Backward Citations)

US2990334A Cited
US3346502A Cited
US3494787A Cited
US3494786A Cited
US3630929A Cited
US3622366A Cited
US3655738A Cited
US3880914A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-06-12 1981-12-12 1982-06-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-06-12 1985-12-12 1986-06-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-06-12 1989-12-12 1990-06-13 $7700.00 Window Closed / Lapsed

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