US5256512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color toner and two-component developer containing same
Assignee: Canon Inc
•
Filing: 1991-12-24
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Granted: 1993-10-26
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Expires: 2011-12-24
Abstract
Abstract Four color toners of yellow, magenta, cyan and black, and four two-component developers containing the four color toners respectively in combination with a resin-coated ferrite carrier suitable for multi-color electrophotographic copying are provided Each of the four-color toners is strictly regulated in relation not only to the carrier but also to the other color toners. More specifically, each color toner is strictly controlled with respect to a particle size distribution, freeness from agglomeration, melting characteristics including heat-absorption peaks and apparent viscosity on melting, chromaticity, triboelectric chargeability and optical toner concentration detection characteristic. Because of the strict regulation of these various parameters, the resultant multi-color toner or developer system shows excellent performances at every stage of multi-color electrophotography including development, transfer and fixing (color-mixing) for a long period of successive copying.
Inventors
- 👤 Hiroyuki Kobayashi
- 👤 Mitsuru Uchida
- 👤 Kenji Okado
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:45
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G13/00; G03G13/01; G03G13/013; G03G13/0133; G03G9/09
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
337 words
A yellow developer for developing electrostatic latent images comprising: (1a) a yellow toner composition containing a yellow toner which in turn contains at least a binder resin and a yellow colorant, and a hydrophobic silica fine powder, and (2a) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin in a weight ratio of 9:10 to 20:80, wherein the binder resin comprises a styrene-acrylic acid ester resin, a styrene-methacrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and a the styrene type resin; the yellow toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the yellow toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the yellow toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the yellow toner containing 0.5 to 7.0 wt. parts of the yellow colorant per 100 wt. parts of binder resin. the yellow toner having chromatically values of a*=-6.5 to -26.5, b*=73.0 to 93.0, and L*=77.0 to 97.0; the yellow toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the yellow toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 2
Dependent Claim
337 words
A yellow developer for developing electrostatic latent images comprising: (1a) a yellow toner composition containing a yellow toner which in turn contains at least a binder resin and a yellow colorant, and a hydrophobic silica fine powder, and (2a) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin in a weight ratio of 9:10 to 20:80, wherein the binder resin comprises a styrene-acrylic acid ester resin, a styrene-methacrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and a the styrene type resin; the yellow toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the yellow toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the yellow toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the yellow toner containing 0.5 to 7.0 wt. parts of the yellow colorant per 100 wt. parts of binder resin. the yellow toner having chromatically values of a*=-6.5 to -26.5, b*=73.0 to 93.0, and L*=77.0 to 97.0; the yellow toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the yellow toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 3
Dependent Claim
62 words
A yellow developer according to claim 1, wherein the binder resin comprises a polyester formed from a di- or more-functional carboxylic acid and a bisphenol derivative represented by the formula: ##STR3## wherein R is an ethylene or propylene group; x and y are respectively a positive integer of 1 or more providing the sum (x+y) of 2 to 10 on an average.
Claim 4
Dependent Claim
35 words
A yellow developer according to claim 2, wherein the carboxylic acid is selected from the group consisting of fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid and mixture thereof.
Claim 5
Dependent Claim
41 words
A yellow developer according to claim 1, wherein the yellow colorant is a colorant selected from the group consisting of C.I. Pigment Yellow 17, C.I. Pigment Yellow 15, C.I. Pigment Yellow 13, C.I. Pigment Yellow 14 and C.I. Pigment Yellow 12.
Claim 6
Dependent Claim
27 words
A yellow developer according to claim 1, wherein the hydrophobic silica fine powder has a hydrophobicity of 30 to 80 as measured by the methanol titration test.
Claim 7
Dependent Claim
31 words
A yellow developer according to claim 1, wherein the hydrophobic silica fine powder is contained in a proportion of 0.01 to 10 wt. parts per 100 wt. parts of the toner.
Claim 8
Dependent Claim
31 words
A yellow developer according to claim 6, wherein the hydrophobic silica fine powder is contained in a proportion of 0.1 to 5 wt. parts per 100 wt. parts of the toner.
Claim 9
Dependent Claim
126 words
A yellow developer according to claim 1, wherein the yellow toner has a volume-average particle size of 11.5 to 13.5 microns, contains 25% by number or less of particles having sizes below 6.35 microns and contains 7% by weight or less of particles having sizes above 20.2 microns; the yellow toner composition has an agglomeration degree of 1.0 to 20%, and an apparent density of 0.25 to 1.0 g/cm 3 ; the yellow toner has an apparent viscosity at 90° C. of 7.5×10 4 to 2×10 6 poise, an apparent viscosity at 100° C. of 10 4 to 3.0×10 5 poise, and a gloss of 7.0% or higher; and the yellow toner has chromaticity values of a*=-11.5 to -21.5, b*=78.0 to 88.0, and L*=82.0 to 92.0.
Claim 10
Dependent Claim
120 words
A yellow developer according to claim 8, wherein the yellow toner has a volume-average particle size of 11.7 to 13.3 microns, contains 20% by number or less of particles having sizes below 6.35 microns and contains 5% by weight or less of particles having sizes above 20.2 microns; the yellow toner composition has an agglomeration degree of 1.0 to 10%, and an apparent density of 0.3 to 0.8 g/cm 3 ; the yellow toner has an apparent viscosity at 90° C. of 10 5 to 10 6 poise, and an apparent viscosity at 100° C. of 10 4 to 2×10 5 poise; and the yellow toner has chromaticity values of a*=-12.5 to -20.5, b*=79.0 to 87.0, and L*=83.0 to 91.0.
Claim 11
Dependent Claim
35 words
A yellow developer according to claim 1 wherein the ferrite carrier is coated with 0.1 to 1 wt. % based on the carrier of the mixture of the fluorine containing resin and the styrenic resin.
Claim 12
Dependent Claim
25 words
A yellow developer according to claim 1, wherein the fluorine-containing resin and the styrenic resin are mixed in a weight ratio of 70:30 to 30:70.
Claim 13
Dependent Claim
35 words
A yellow developer according to claim 1, wherein the fluorine-containing resin is polyvinylidene fluoride, polytetrafluoroethylene or vinylidene fluoride-tetrafluoroethylene copolymer, and the styrenic resin is styrene-methyl methacrylate copolymer, styrene-2-ethylhexyl acrylate copolymer or styrene-2-ethylhexyl acrylate-methyl methacrylate copolymer.
Claim 14
Dependent Claim
25 words
A yellow developer according to claim 12, wherein the fluorine-containing resin is vinylidene fluoride-tetrafluoroethylene copolymer, and the styrene type resin is styrene-2-ethylhexyl acrylate-methyl methacrylate copolymer.
Claim 15
Dependent Claim
332 words
A magenta developer for developing electrostatic latent images comprising: (1b) a magenta toner composition containing a magenta toner which in turn contains at least a binder resin and a magenta colorant, and a hydrophobic silica fine powder, and (2b) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin in a weight ratio of 90:10 to 20:80, wherein the binder resin comprises a styrene-acrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and the styrene type resin; the magenta toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the magenta toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the magenta toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the magenta toner containing 0.1 to 9.0 wt. parts of the yellow colorant per 100 wt. parts of the binder resin. the magenta toner having chromatically values of a*=-60.0 to -80.0, b*=-12.0 to -32.0, and L*=40.0 to 60.0; the magenta toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the magenta toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 16
Dependent Claim
332 words
A magenta developer for developing electrostatic latent images comprising: (1b) a magenta toner composition containing a magenta toner which in turn contains at least a binder resin and a magenta colorant, and a hydrophobic silica fine powder, and (2b) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin in a weight ratio of 90:10 to 20:80, wherein the binder resin comprises a styrene-acrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and the styrene type resin; the magenta toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the magenta toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the magenta toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the magenta toner containing 0.1 to 9.0 wt. parts of the yellow colorant per 100 wt. parts of the binder resin. the magenta toner having chromatically values of a*=-60.0 to -80.0, b*=-12.0 to -32.0, and L*=40.0 to 60.0; the magenta toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the magenta toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 17
Dependent Claim
62 words
A magenta developer according to claim 14, wherein the binder resin comprises a polyester formed from a di- or more-functional carboxylic acid and a bisphenol derivative represented by the formula: ##STR4## wherein R is an ethylene or propylene group; x and y are respectively a positive integer of 1 or more providing the sum (x+y) of 2 to 10 on an average.
Claim 18
Dependent Claim
35 words
A magenta developer according to claim 15, wherein the carboxylic acid is selected from the group consisting of fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid and mixture thereof.
Claim 19
Dependent Claim
41 words
A magenta developer according to claim 14, wherein the magenta colorant is a colorant selected from the group consisting of C.I. Pigment Red 5, C.I. Pigment Red 3, C.I. Pigment Red 2, C.I. Pigment Red 6 and C.I. Pigment Red 7.
Claim 20
Dependent Claim
27 words
A magenta developer according to claim 14, wherein the hydrophobic silica fine powder has a hydrophobicity of 30 to 80 as measured by the methanol titration test.
Claim 21
Dependent Claim
31 words
A magenta developer according to claim 14, wherein the hydrophobic silica fine powder is contained in a proportion of 0.01 to 10 wt. parts per 100 wt. parts of the toner.
Claim 22
Dependent Claim
31 words
A magenta developer according to claim 19, wherein the hydrophobic silica fine powder is contained in a proportion of 0.1 to 5 wt. parts per 100 wt. parts of the toner.
Claim 23
Dependent Claim
127 words
A magenta developer according to claim 14, wherein the magenta toner has a volume-average particle size of 11.5 to 13.5 microns, contains 25% by number or less of particles having sizes below 6.35 microns and contains 7% by weight or less of particles having sizes above 20.2 microns; the magenta toner composition has an agglomeration degree of 1.0 to 20%, and an apparent density of 0.25 to 1.0 g/cm 3 ; the magenta toner has an apparent viscosity at 90° C. of 7.5×10 4 to 2×10 6 poise, an apparent viscosity at 100° C. of 10 4 to 3.0×10 5 poise, and a gloss of 7.0 % or higher; and the magenta toner has chromaticity values of a*=65.0 to 75.0, b*=-17.0 to -27.0, and L*=40.0 to 55.0.
Claim 24
Dependent Claim
120 words
A magenta developer according to claim 21, wherein the magenta toner has a volume-average particle size of 11.7 to 13.3 microns, contains 20% by number or less of particles having sizes below 6.35 microns and contains 5% by weight or less of particles having sizes above 20.2 microns; the magenta toner composition has an agglomeration degree of 1.0 to 10%, and an apparent density of 0.3 to 0.8 g/cm 3 ; the magenta toner has an apparent viscosity at 90° C. of 10 5 to 10 6 poise, and an apparent viscosity at 100° C. of 10 4 to 2×10 5 poise; and the magenta toner has chromaticity values of a*=66.0 to 74.0, b*=-18.0 to -26.0 and L*=44.0 to 54.0.
Claim 25
Dependent Claim
35 words
A magenta developer according to claim 14, wherein the ferrite carrier is coated with 0.1 to 1 wt. % based on the carrier of the mixture of the fluorine containing resin and the styrenic resin.
Claim 26
Dependent Claim
25 words
A magenta developer according to claim 14, wherein the fluorine-containing resin and the styrenic resin are mixed in a weight ratio of 70:30 to 30:70.
Claim 27
Dependent Claim
35 words
A magenta developer according to claim 14, wherein the fluorine-containing resin is polyvinylidene fluoride, polytetrafluoroethylene or vinylidene fluoride-tetrafluoroethylene copolymer, and the styrenic resin is styrene-methyl methacrylate copolymer, styrene-2-ethylhexyl acrylate copolymer or styrene-2-ethylhexyl acrylate-methyl methacrylate copolymer.
Claim 28
Dependent Claim
24 words
A magenta developer according to claim 25, wherein the fluorine-containing resin is vinylidene fluoride-tetrafluoroethylene copolymer, and the styrenic resin is styrene-2-ethylhexyl acrylate-methyl methacrylate copolymer.
Claim 29
Dependent Claim
328 words
A cyan developer for developing electrostatic latent images comprising: (1c) a cyan toner composition containing a cyan toner which in turn contains at least a binder resin and a cyan colorant, and a hydrophobic silica fine powder, and (2b) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin, wherein the binder resin comprises a styrene-acrylic acid ester resin, a styrene-methacrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and the styrene type resin; the cyan toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the cyan toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the cyan toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the cyan toner containing 0.1 to 9.0 wt. parts of the cyan colorant per 100 wt. parts of binder resin; the cyan toner having chromatically values of a*=-8.0 to -28.0, b*=-30.0 to -50.0, and L*=39.0 to 59.0; the cyan toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the cyan toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 30
Dependent Claim
328 words
A cyan developer for developing electrostatic latent images comprising: (1c) a cyan toner composition containing a cyan toner which in turn contains at least a binder resin and a cyan colorant, and a hydrophobic silica fine powder, and (2b) a ferrite carrier coated with a mixture of a fluorine-containing resin and a styrenic resin, wherein the binder resin comprises a styrene-acrylic acid ester resin, a styrene-methacrylic acid ester resin or a polyester resin, the ferrite carrier has an average particle size of 30 to 65 microns, and the ferrite carrier is coated with 0.01 to 5 wt. % based on the carrier of the mixture of the fluorine-containing resin and the styrene type resin; the cyan toner having a volume-average particle size of 11.0 to 14.0 microns containing 30% by number or less of particles having sizes below 6.35 microns and containing 9% by weight or less of particles having sizes above 20.2 microns; the cyan toner composition having an agglomeration degree of 25% or below and an apparent density of 0.2 to 1.5 g/cm 3 ; the cyan toner having an apparent viscosity at 100° C. of 10 4 to 5×10 5 poise, an apparent viscosity at 90° C. of 5×10 4 to 5×10 6 poise, a DSC heat-absorption peak at 58° to 72° C., and a gloss of 5.0% or higher; the cyan toner containing 0.1 to 9.0 wt. parts of the cyan colorant per 100 wt. parts of binder resin; the cyan toner having chromatically values of a*=-8.0 to -28.0, b*=-30.0 to -50.0, and L*=39.0 to 59.0; the cyan toner showing a triboelectric charge of -5 to -20 micro-C/g with respect to the ferrite carrier coated with the mixture of the fluorine-containing resin and the styrenic resin containing 70 wt. % or more of carrier particles having sizes of 250 mesh-pass and 350 mesh-on; and the cyan toner having a spectral reflectance of 60% or more in an infrared region of 900 to 1000 nm.
Claim 31
Dependent Claim
62 words
A cyan developer according to claim 27; wherein the binder resin comprises a polyester formed from a di- or more-functional carboxylic acid and a bisphenol derivative represented by the formula: ##STR5## wherein R is an ethylene or propylene group; x and y are respectively a positive integer of 1 or more providing the sum (x+y) of 2 to 10 on an average.
Claim 32
Dependent Claim
35 words
A cyan developer according to claim 28, wherein the carboxylic acid is selected from the group consisting of fumaric acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid and mixture thereof.
Claim 33
Dependent Claim
36 words
A cyan developer according to claim 27, wherein the cyan colorant is a colorant selected from the group consisting of C.I. Pigment Blue 15, C.I. Pigment Blue 16, and copper phthalocyanine pigments having 2-3 carboxybenzamidomethyl groups.
Claim 34
Dependent Claim
28 words
A cyan developer according to claim 27, wherein the is hydrophobic silica fine powder has a hydrophobicity of 30 to 80 as measured by the methanol titration test.
Claim 35
Dependent Claim
31 words
A cyan developer according to claim 27, wherein the hydrophobic silica fine powder is contained in a proportion of 0.01 to 10 wt. parts per 100 wt. parts of the toner.
Claim 36
Dependent Claim
31 words
A cyan developer according to claim 32, wherein the hydrophobic silica fine powder is contained in a proportion of 0.1 to 5 wt. parts per 100 wt. parts of the toner.
Claim 37
Dependent Claim
126 words
A cyan developer according to claim 27, wherein the cyan toner has a volume-average particle size of 11.5 to 13.5 microns, contains 25% by number or less of particles having sizes below 6.35 microns and contains 7% by weight or less of particles having sizes above 20.2 microns; the cyan toner composition has an agglomeration degree of 1.0 to 20%, and an apparent density of 0.25 to 1.0 g/cm 3 ; the cyan toner has an apparent viscosity at 90° C. of 7.5×10 4 to 2×10 6 poise, an apparent viscosity at 100° C. of 10 4 to 3.0×10 5 poise, and a gloss of 7.0% or higher; and the cyan toner has chromaticity values of a*=-10.0 to -27.0, b*=-33.0 to -45.0, and L*=44.0 to 59.0.
Claim 38
Dependent Claim
120 words
A cyan developer according to claim 34, wherein the cyan toner has a volume-average particle size of 11.7 to 13.3 microns, contains 20% by number or less of particles having sizes below 6.35 microns and contains 5% by weight or less of particles having sizes above 20.2 microns; the cyan toner composition has an agglomeration degree of 1.0 to 10%, and an apparent density of 0.3 to 0.8 g/cm 3 ; the cyan toner has an apparent viscosity at 90° C. of 10 5 to 10 6 poise, and an apparent viscosity at 100° C. of 10 4 to 2×10 5 poise; and the cyan toner has chromaticity values of a*=-14.0 to -25.0, b*=-35.0 to -44.0, and L*=45.0 to 57.0.
Claim 39
Dependent Claim
35 words
A cyan developer according to claim 27, wherein the ferrite carrier is coated with 0.1 to 1 wt. % based on the carrier of the mixture of the fluorine containing resin and the styrenic resin.
Claim 40
Dependent Claim
25 words
A cyan developer according to claim 27, wherein the fluorine-containing resin and the styrenic resin are mixed in a weight ratio of 70:30 to 30:70.
Claim 41
Dependent Claim
35 words
A cyan developer according to claim 27, wherein the fluorine-containing resin is polyvinylidene fluoride, polytetrafluoroethylene or vinylidene fluoride-tetrafluoroethylene copolymer, and the styrenic resin is styrene-methyl methacrylate copolymer, styrene-2-ethylhexyl acrylate copolymer or styrene-2-ethylhexyl acrylate-methyl methacrylate copolymer.
Claim 42
Dependent Claim
25 words
A cyan developer according to claim 38 wherein the fluorine-containing resin is vinylidene fluoride-tetrafluoroethylene copolymer, and the styrenic resin is styrene-2-ethylhexyl acrylate methyl methacrylate copolymer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-10-25 | 1997-04-26 | 1997-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-10-25 | 2001-04-26 | 2001-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-10-25 | 2005-04-26 | 2005-10-26 | $7700.00 | Window Closed / Lapsed |