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US4223070A Expired / Lapsed US ⏱️ 0.0 years remaining

Impregnated porous granules with slow release pore membranes and process therefor

Assignee: Zeneca Inc
•
Filing: 1978-05-04
•
Granted: 1980-09-16
•
Expires: 1998-05-04
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Abstract

Abstract Open-ended pores of a porous granule are filled with a liquid material which is at least partially immiscible with water, and sealed with a porous polyurea membrane which limits the release rate of the material into the surrounding medium. The membrane is formed by (a) applying to the bare granule an organic solution comprising the liquid material and an organic polyisocyanate, followed by (b) applying to the granule an aqueous solution comprising water and a catalytic amount of a catalyst selected from the group consisting of a basic organic tertiary amine and an alkyl tin carboxylate.

Inventors

  • 👤 Alice U. Hahn
  • 👤 Richard H. Rider
  • 👤 Herbert B. Scher
  • 👤 Garrard L. Hargrove

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 16:45
CPC Classifications
B; B01; B01J; B01J2/00; B01J2/006; A; A01; A01N; A01N25/00; A01N25/26; C; C05; C05G; C05G3/00; C05G3/40; C05G3/44; Y; Y10; Y10S; Y10S428/00; Y10S428/905; Y10S428/907; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 103 words
A method for impregnating a porous granule with a material which is at least partially immiscible with water and sealing said material within the pores of said granule by covering the openings of said pores with a porous membrane to effect a slow rate of release of said material from said granule, which comprises (a) applying to said granule an organic solution comprising said material and an organic polyisocyanate, and (b) applying to said granule an aqueous solution comprising water and a catalytic amount of a catalyst selected from the group consisting of a basic organic tertiary amine and an alkyl tin carboxylate.
Claim 2
Independent Claim 103 words
A method for impregnating a porous granule with a material which is at least partially immiscible with water and sealing said material within the pores of said granule by covering the openings of said pores with a porous membrane to effect a slow rate of release of said material from said granule, which comprises (a) applying to said granule an organic solution comprising said material and an organic polyisocyanate, and (b) applying to said granule an aqueous solution comprising water and a catalytic amount of a catalyst selected from the group consisting of a basic organic tertiary amine and an alkyl tin carboxylate.
Claim 3
Dependent Claim 15 words
A method according to claim 1 in which said organic polyisocyanate is an aromatic polyisocyanate.
Claim 4
Dependent Claim 15 words
A method according to claim 1 in which said organic polyisocyanate is a polymethylene polyphenylisocyanate.
Claim 5
Dependent Claim 29 words
A method according to claim 1 in which the concentration of organic polyisocyanate in said organic solution is within the range of about 2% to about 75% by weight.
Claim 6
Dependent Claim 30 words
A method according to claim 1 in which the concentration of said organic polyisocyanate in said organic solution is within the range of about 5% to about 50% by weight.
Claim 7
Dependent Claim 29 words
A method according to claim 1 in which the concentration of said catalyst in said aqueous solution is within the range of about 0.01% to about 10% by weight.
Claim 8
Dependent Claim 29 words
A method according to claim 1 in which the concentration of said catalyst in said aqueous solution is within the range of about 0.05% to about 5% by weight.
Claim 9
Dependent Claim 29 words
A method according to claim 1 in which said organic and aqueous solutions are applied at a temperature within the range of about 15° C. to about 30° C.
Claim 10
Dependent Claim 17 words
A method according to claim 1 in which said material sealed within said pores is S-ethyl hexahydro-1H-azepine-1-carbothioate.
Claim 11
Dependent Claim 18 words
A method according to claim 1 in which said material sealed within said pores is S-ethyl diisobutyl thiocarbamate.
Claim 12
Dependent Claim 17 words
A method according to claim 1 in which said material sealed within said pores is S-propyl dipropylthiocarbamate.
Claim 13
Dependent Claim 17 words
A method according to claim 1 in which said material sealed within said pores is S-ethyl dipropylthiocarbamate.
Claim 14
Dependent Claim 18 words
A method according to claim 1 in which said material sealed within said pores is O-ethyl S-phenyl ethylphosphonodithioate.
Claim 15
Dependent Claim 17 words
A method according to claim 1 in which said material sealed within said pores is S-ethyl cyclohexylethylthiocarbamate.
Claim 16
Dependent Claim 83 words
An article of manufacture which comprises a porous granule impregnated with a material which is at least partially immiscible with water, the pores of which are sealed with a porous polyurea membrane formed by (a) applying to said granule an organic solution comprising said material and an organic polyisocyanate, and (b) applying to said granule an aqueous solution comprising water and a catalytic amount of a catalyst selected from the group consisting of a basic organic tertiary amine and an alkyl tin carboxylate.
Claim 17
Dependent Claim 83 words
An article of manufacture which comprises a porous granule impregnated with a material which is at least partially immiscible with water, the pores of which are sealed with a porous polyurea membrane formed by (a) applying to said granule an organic solution comprising said material and an organic polyisocyanate, and (b) applying to said granule an aqueous solution comprising water and a catalytic amount of a catalyst selected from the group consisting of a basic organic tertiary amine and an alkyl tin carboxylate.
Claim 18
Dependent Claim 17 words
An article of manufacture according to claim 15 in which said organic polyisocyanate is an aromatic polyisocyanate.
Claim 19
Dependent Claim 17 words
An article of manufacture according to claim 15 in which said organic polyisocyanate is a polymethylene polyphenylisocyanate.
Claim 20
Dependent Claim 32 words
An article of manufacture according to claim 15 in which the concentration of said organic polyisocyanate in said organic solution is within the range of about 2% to about 75% by weight.
Claim 21
Dependent Claim 32 words
An article of manufacture according to claim 15 in which the concentration of said organic polyisocyanate in said organic solution is within the range of about 5% to about 50% by weight.
Claim 22
Dependent Claim 31 words
An article of manufacture according to claim 15 in which the concentration of said catalyst in said aqueous solution is within the range of about 0.01% to about 10% by weight.
Claim 23
Dependent Claim 31 words
An article of manufacture according to claim 15 in which the concentration of said catalyst in said aqueous solution is within the range of about 0.05% to about 5% by weight.
Claim 24
Dependent Claim 31 words
An article of manufacture according to claim 15 in which said organic and aqueous solutions are applied at a temperature within the range of about 15° C. to about 30° C.
Claim 25
Dependent Claim 19 words
An article of manufacture according to claim 15 in which said material sealed within said pores is S-ethyl hexahydro-1H-azepine-1-carbothioate.
Claim 26
Dependent Claim 19 words
An article of manufacture according to claim 15 in which said material sealed within said pores is S-ethyl diisobutylthiocarbamate.
Claim 27
Dependent Claim 19 words
An article of manufacture according to claim 15 in which said material sealed within said pores is S-propyl dipropylthiocarbamate.
Claim 28
Dependent Claim 19 words
An article of manufacture according to claim 15 in which said material sealed within said pores is S-ethyl dipropylthiocarbamate.
Claim 29
Dependent Claim 20 words
An article of manufacture according to claim 15 in which said material sealed within said pores is O-ethyl S-phenyl ethylphosphonodithioate.
Claim 30
Dependent Claim 19 words
An article of manufacture according to claim 15 in which said material sealed within said pores is S-ethyl cyclohexylethylthiocarbamate.

References Cited (Backward Citations)

US3223518A Cited
GB1091077A Cited
US3821135A Cited
US4119565A Cited
US4140516A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1983-09-16 1984-03-17 1984-09-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1987-09-16 1988-03-17 1988-09-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1991-09-16 1992-03-17 1992-09-16 $7700.00 Window Closed / Lapsed

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