US4155895A
Expired / Lapsed
US
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Thermotropic ink
Assignee: Primerica Inc
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Filing: 1978-05-30
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Granted: 1979-05-22
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Expires: 1998-05-30
Abstract
Abstract An ink composition is provided which is suitable for use on bare metal, for example, tinplate or aluminum as well as on such metals having organic coatings applied to surfaces thereof. The compositions may also be used on plastic containers or retortable pouches comprising plastic or plastic-metal foil laminates. The inks are suitable for use in contact printers or in jet ink printing techniques. The ink compositions are thermotropic, i.e. they change color in the presence of steam at elevated temperature and are useful as sterilization indicators. The inks comprise essentially a binder resin component, an alcohol solvent and a colorant which reacts in the presence of steam at elevated temperature to produce a visible and permanent color change.
Inventors
- 👤 Stanley E. Rohowetz
- 👤 James D. Specht
- 👤 Lee J. Murray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:38
CPC Classifications
A; A61; A61L; A61L2/00; A61L2/26; A61L2/28; C; C09; C09D; C09D11/00; C09D11/30; C09D11/36; C09D11/50; Y; Y10; Y10S; Y10S252/00; Y10S252/962
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
74 words
A thermotropic ink composition suitable for use in contact or ink jet printing operations comprising a solution of (a) a soluble resole resin; (b) a thermotropic dye capable of undergoing a visible change in color and (c) a solvent for said resin and dye consisting essentially of a lower aliphatic monohydric alcohol or mixture thereof, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 2
Dependent Claim
74 words
A thermotropic ink composition suitable for use in contact or ink jet printing operations comprising a solution of (a) a soluble resole resin; (b) a thermotropic dye capable of undergoing a visible change in color and (c) a solvent for said resin and dye consisting essentially of a lower aliphatic monohydric alcohol or mixture thereof, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 3
Dependent Claim
25 words
An ink composition as claimed in claim 1 wherein said resole resin has a molecular weight within the range of about 1300 to about 10,000.
Claim 4
Dependent Claim
30 words
An ink composition as claimed in 2 wherein said resole resin is an alkaline catalyzed phenol-formaldehyde or resorcinol-formaldehyde condensation product in which the ratio of formaldehyde is greater than 1.
Claim 5
Dependent Claim
40 words
An ink composition as claimed in claim 2 wherein said solvent comprises a lower aliphatic monohydric alcohol or mixture thereof with one or more solvents selected from the group consisting of methyl cellosolve, ethyl cellosolve, dimethyl formamide and dimethyl sulfoxide.
Claim 6
Dependent Claim
98 words
A thermotropic ink composition suitable for use in contact or ink jet printing operations comprising a solution of (a) from about 3 to 30% by weight of a soluble resole resin having a molecular weight of about 1300 to 10,000; (b) from about 0.1 to 5% by weight of a thermotropic phenazine dye capable of undergoing a visible change in color and (c) a solvent for said dye and resin consisting essentially of a lower aliphatic monohydric alcohol, said ink composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 7
Dependent Claim
98 words
A thermotropic ink composition suitable for use in contact or ink jet printing operations comprising a solution of (a) from about 3 to 30% by weight of a soluble resole resin having a molecular weight of about 1300 to 10,000; (b) from about 0.1 to 5% by weight of a thermotropic phenazine dye capable of undergoing a visible change in color and (c) a solvent for said dye and resin consisting essentially of a lower aliphatic monohydric alcohol, said ink composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 8
Dependent Claim
26 words
An ink composition as claimed in claim 5 wherein said resole resin is a phenol-formaldehyde, said thermotropic dye is Indoine Blue and said solvent is methanol.
Claim 9
Dependent Claim
12 words
An ink composition as claimed in claim 5 additionally comprising a surfactant.
Claim 10
Dependent Claim
16 words
An ink composition as claimed in claim 7 wherein said surfactant is a fluorinated alkyl ester.
Claim 11
Dependent Claim
105 words
A thermotropic ink composition suitable for use in contact or ink jet printing on coated and uncoated metal and plastic surfaces comprising a solution of: about 5% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,00; about 1% of an azo-phenazine thermotropic dye, about 47% methanol, about 47% methyl cellosolve, and about 0.01% fluorinated alkyl ester surfactant, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 12
Dependent Claim
105 words
A thermotropic ink composition suitable for use in contact or ink jet printing on coated and uncoated metal and plastic surfaces comprising a solution of: about 5% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,00; about 1% of an azo-phenazine thermotropic dye, about 47% methanol, about 47% methyl cellosolve, and about 0.01% fluorinated alkyl ester surfactant, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 13
Dependent Claim
115 words
A thermotropic ink composition suitable for use in contact or ink jet printing on coated and uncoated metal and plastic surfaces comprising a solution of: about 12.2% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 39.1% ethyl cellosolve, about 40.4% methanol, about 0.6% dimethylamine hydrochloride, about 1.5% of a fluorinated alkyl ester surfactant, about 5.1% dimethyl sulfoxide and about 0.9% of an azo-phenazine thermotropic dye, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 14
Dependent Claim
115 words
A thermotropic ink composition suitable for use in contact or ink jet printing on coated and uncoated metal and plastic surfaces comprising a solution of: about 12.2% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 39.1% ethyl cellosolve, about 40.4% methanol, about 0.6% dimethylamine hydrochloride, about 1.5% of a fluorinated alkyl ester surfactant, about 5.1% dimethyl sulfoxide and about 0.9% of an azo-phenazine thermotropic dye, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 15
Dependent Claim
22 words
An ink composition as claimed in either of claims 9 or 10 in which the azo-phenazine dye is an Indoine Blue dye.
Claim 16
Independent Claim
74 words
A method of indicating steam sterilization of articles which comprises applying markings to a surface of said articles using a thermotropic ink composition comprising a solution of (a) a soluble resole resin (b) a thermotropic dye and (c) a solvent for said resin and dye and exposing the marked articles to steam at a temperature of at least about 215° F. for a time sufficient to effect a visible color change in said markings.
Claim 17
Independent Claim
74 words
A method of indicating steam sterilization of articles which comprises applying markings to a surface of said articles using a thermotropic ink composition comprising a solution of (a) a soluble resole resin (b) a thermotropic dye and (c) a solvent for said resin and dye and exposing the marked articles to steam at a temperature of at least about 215° F. for a time sufficient to effect a visible color change in said markings.
Claim 18
Dependent Claim
18 words
A method as claimed in claim 12 wherein said articles are coated or uncoated tinplate and aluminum cans.
Claim 19
Dependent Claim
25 words
A method as claimed in claim 13 in which said resole resin is a phenol-formaldehyde resin having a molecular weight of about 1300 to 10,000.
Claim 20
Independent Claim
17 words
A method as claimed in claims 12, 13, or 14 wherein said dye is a phenazine dye.
Claim 21
Independent Claim
22 words
A method as claimed in claims 12, 13, 14, or 15 wherein said solvent consists essentially of a lower aliphatic monohydric alcohol.
Claim 22
Dependent Claim
21 words
A method as claimed in claim 16, wherein said markings are applied by jet ink printing of said thermotropic ink composition.
Claim 23
Dependent Claim
20 words
A method as claimed in claim 16 wherein said markings are applied by contact printing of said thermotropic ink composition.
Claim 24
Independent Claim
134 words
A method of indicating steam sterilization of coated or uncoated tinplate or aluminum or plastic containers which comprises: applying markings to a surface of said container using a thermotropic ink composition comprising a solution of (a) from about 3 to 30% by weight a soluble phenol-formaldehyde resole resin: (b) from about 0.1 to 5% by weight of a thermotropic phenazine dye (c) from about 0.01 to 0.1% by weight of a fluorinated alkyl ester surfactant and (d) sufficient amount of a solvent for said resin and dye to constitute a 100% solution said solvent consisting essentially of a lower aliphatic monohydric alcohol or mixture thereof; and exposing the marked containers to steam at a temperature of at least about 215° F. for a time sufficient to effect a visible color change in said markings.
Claim 25
Independent Claim
134 words
A method of indicating steam sterilization of coated or uncoated tinplate or aluminum or plastic containers which comprises: applying markings to a surface of said container using a thermotropic ink composition comprising a solution of (a) from about 3 to 30% by weight a soluble phenol-formaldehyde resole resin: (b) from about 0.1 to 5% by weight of a thermotropic phenazine dye (c) from about 0.01 to 0.1% by weight of a fluorinated alkyl ester surfactant and (d) sufficient amount of a solvent for said resin and dye to constitute a 100% solution said solvent consisting essentially of a lower aliphatic monohydric alcohol or mixture thereof; and exposing the marked containers to steam at a temperature of at least about 215° F. for a time sufficient to effect a visible color change in said markings.
Claim 26
Dependent Claim
13 words
A method as claimed in claim 19 wherein said dye is Indoine Blue.
Claim 27
Dependent Claim
21 words
A method as claimed in claim 19 wherein said markings are applied by jet ink printing of said thermotropic ink composition.
Claim 28
Independent Claim
19 words
A method as claimed in 19 wherein said markings are applied by contact printing of said thermotropic ink composition.
Claim 29
Dependent Claim
26 words
A method as claimed in claim 19 wherein said plastic containers are comprised of polyethylene, polypropylene, vinyl chloride-vinylidene chloride copolymer, polyester, polyvinyl or polyamide synthetic resins.
Claim 30
Independent Claim
110 words
A method of indicating steam sterilization of coated or uncoated tinplate or aluminum containers which comprises: applying markings to a surface of said container using a thermotropic ink composition comprising: about 5% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 1% of an azo-phenazine thermotropic dye, about 47% methanol, about 47% methyl cellosolve, and about 0.01% fluorinated alkyl ester surfactant, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 31
Independent Claim
110 words
A method of indicating steam sterilization of coated or uncoated tinplate or aluminum containers which comprises: applying markings to a surface of said container using a thermotropic ink composition comprising: about 5% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 1% of an azo-phenazine thermotropic dye, about 47% methanol, about 47% methyl cellosolve, and about 0.01% fluorinated alkyl ester surfactant, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 32
Independent Claim
120 words
A method for indicating steam sterilization of coated and uncoated metal and plastic surfaces which comprises: applying markings to said surfaces using a thermotropic ink solution comprising: a solution of about 12.2% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 39.1% ethyl cellosolve, about 40.4% methanol, about 0.6% dimethylamine hydrochloride, about 1.5% of a fluorinated alkyl ester surfactant, about 5.1% dimethyl sulfoxide and about 0.9% of an azo-phenazine thermotropic dye, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 33
Independent Claim
120 words
A method for indicating steam sterilization of coated and uncoated metal and plastic surfaces which comprises: applying markings to said surfaces using a thermotropic ink solution comprising: a solution of about 12.2% phenol formaldehyde resole resin derived from the alkaline catalyzed condensation of phenol and formaldehyde in which the ratio of formaldehyde to phenol is greater than 1, said resole resin having a molecular weight of about 1300 to 10,000; about 39.1% ethyl cellosolve, about 40.4% methanol, about 0.6% dimethylamine hydrochloride, about 1.5% of a fluorinated alkyl ester surfactant, about 5.1% dimethyl sulfoxide and about 0.9% of an azo-phenazine thermotropic dye, said composition undergoing a color change upon exposure to steam at a temperature of at least about 215° F.
Claim 34
Independent Claim
20 words
A method as claimed in either of claims 24 or 25 wherein the azo-phenazine dye is an Indoine Blue dye.
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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) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |