PS

Pyong-Nae Son

EA E.I. Du Pont De Nemours And: 1 patents #4,343 of 8,010Top 55%
📍 Akron, OH: #38 of 1,966 inventorsTop 2%
🗺 Ohio: #1,294 of 73,341 inventorsTop 2%
Overall (All Time): #95,185 of 4,157,543Top 3%
36
Patents All Time

Issued Patents All Time

Showing 1–25 of 36 patents

Patent #TitleCo-InventorsDate
5270471 Process for making alkylated polyalkylenepolyamines by selective alkylation John T. Lai 1993-12-14
5240977 Multi-component stabilizer system for polyolefins pigmented with azo and disazo pigments George Kletecka, John T. Lai 1993-08-31
5239071 Process for methylating a hindered nitrogen atom in an inert non-aqueous solvent Victor L. Ledesma, George Kletecka 1993-08-24
5189173 Alkylated polyalkylene polyamines and process for selective alkylation John T. Lai 1993-02-23
5098944 Thermooxidative stabilization of polymers with a N4-alkylated oxo-piperazinyl-triazine George Kletecka, John T. Lai 1992-03-24
5096949 N,N-disubstituted, .alpha.-(3,5-dialkyl-4-hydroxyphenyl)-.alpha.,.alpha.-disubstituted acetamides and composition stabilized therewith John T. Lai 1992-03-17
5071981 Alkylated oxo-piperanzinyl-triazine John T. Lai, Peter D. Smith, Leonard E. R. Kosinski 1991-12-10
5053505 Process for the manufacture of a tri-substituted triazine stabilizer John T. Lai, Ronald M. Kovach 1991-10-01
4929653 Stabilized pigmented polypropylene fiber resistant to gas fade George Kletecka, John T. Lai 1990-05-29
4920228 N,N-disubstituted, .alpha.-(3,5-dialkyl-4-hydroxyphenyl)-.alpha.,.alpha.-disubstituted acetamides and composition stabilized therewith John T. Lai 1990-04-24
4841053 Process for desensitizing a 1-(alkylamino)alkyl-polysubstituted piperazinone during recovery Charles P. Jacobs, Ronald M. Kovach, John T. Lai 1989-06-20
4797438 Stabilized gamma-irradiated polypropylene and sterilizable articles thereof George Kletecka, John T. Lai 1989-01-10
4780495 N -(substituted)-.alpha.-(3,5-dialkyl-4-hydroxyphenyl)-.alpha.,.alpha.-disu bstituted acetamides, and composition stabilized therewith John T. Lai 1988-10-25
4722806 Alkylated polyalkylenepolyamines, substituted oxo-piperazinyl-triazines and UV light stabilized compositions John T. Lai 1988-02-02
4698446 Synthesis of polyamines and mixture formed thereby, of diprimary polyalkylene polyamines with disubstituted N-adjacent terminal carbon atom(s) John T. Lai 1987-10-06
4692487 1,2-ethanediyl-bis-2-piperazinone esters, oligomers thereof, and compositions stabilized thereby John T. Lai 1987-09-08
4687850 Purification of 1-(2-amino-2-alkylpropyl)-3,3,5,5-tetraalkylpiperazinones Charles P. Jacobs 1987-08-18
4675353 Hindered 2-keto-1,4-diazacycloalkane oligomers containing triazine rings and compositions stabilized thereby John T. Lai 1987-06-23
4650903 Oligomeric amides as synergists for antioxidants and UV stabilizers John T. Lai 1987-03-17
4639479 Polyalkylenepolyamine having pendant substituted oxo-piperazinyltriazines and UV light stabilized compositions John T. Lai 1987-01-27
4629752 Substituted oxo-piperazinyl-triazines and UV light stabilized compositions Robert W. Layer, John T. Lai 1986-12-16
4547538 Alkylated polyalkylenepolyamines, substituted oxo-piperazinyl-triazines and UV light stabilized compositions John T. Lai 1985-10-15
4480092 Alkylated polyalkylenepolyamines, substituted oxo-piperazinyl-triazines John T. Lai 1984-10-30
4477665 Substituted 2-keto-1,4-diazacycloalkanes John T. Lai 1984-10-16
4472548 Oligomeric phenylphosphonites George Kletecka 1984-09-18