Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-04-04
2001-09-04
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S174000, C510S432000, C510S437000, C510S488000, C510S491000, C134S042000
Reexamination Certificate
active
06284720
ABSTRACT:
DESCRIPTION
1. Technical Field
The present invention relates to a cleaning preparation that is biodegradable and generally benign to human health, and more particularly to a mixture of a lactate ester and an ester of a fatty acid derived from an edible oil; the mixture provides effective solvency for a broad range of tasks. This blended solvent is shown to provide effective performance for de-inking and as a general surface cleaning agent that provides for a non-toxic, cost effective alternative to commonly used toxic solvents.
2. Background Art
The printing industry is one of the largest manufacturing industries in the U.S. The industry also generates a large amount of petrochemical waste, much in the form of volatile organic compounds, which are linked to ground-level ozone formation that is associated with smog and other health hazards.
The Environmental Protection Agency reported that the top ten polluting petrochemicals used in the printing industry are (in decreasing order of millions of pounds) toluene, methyl ethyl ketone, glycol ethers, xylene (mixed isomers), tetrachloroethylene, methyl isobutyl ketone, methanol, 1,1,1-trichloroethane, dichloromethane and ethylene glycol. The top four make up the largest amount of the total by far, with toluene making up 75 percent of the total. The solvents are used for cleaning the presses, rollers and other equipment, but also as components of the ink formulations. Many of the petrochemical compositions for cleaning ink contain aromatic groups that do not biodegrade well, and such compositions are undesirable from an environmental standpoint.
A solvent is a substance that is generally capable of dissolving another substance, or solute, to form a uniformly dispersed mixture (solution) at the molecular or ionic level. Solvents are either polar (high dielectric constant) or non-polar (low dielectric constant). Water, the most common solvent, is strongly polar having a dielectric constant of 81. Hydrocarbon solvents are non-polar and are comprised of two groups, aliphatics such as alkanes and alcohols, and aromatics, which generally have a higher solvency power than aliphatics. Other organic solvent groups are esters, ethers, ketones, amines, nitrated hydrocarbons and halogenated hydrocarbons.
The chief uses of organic solvents include dissolution of coatings (paints, varnishes, and laquers), industrial and household cleaners, printing inks, and extractive processes. Because many solvents are flammable and toxic to health, there is a need to develop safer solvents for commercial use without sacrificing critical performance.
U.S. Pat. No. 5,964,007 discloses the use of aliphatic ketone (methyl ethyl ketone preferred, methyl ketone, ethyl ketone, propyl ketone and butyl ketone) and alkylene halide (methylene chloride preferred, ethylene chloride and propylene chloride) solvents for cleaning contact cleaner rolls.
U.S. Pat. No. 6,035,483 discloses the use of a highly viscous cleaning agent to clean cylinders of printing presses.
For decades industrial and household cleaning products have been utilized to provide certain tasks such as paint removers, ink removers, degreasers, etc. Solvents are also used to clean, maintain, and prepare wood, metal, masonry, natural and synthetic fabrics, plastic components, electronic components. Although providing the needs of these many and mission-critical tasks, most solvents generally, are toxic, thus posing a threat to health and to the environment. These environmental and health threats include ozone depleting air pollutants and water pollution that threaten aquatic organisms and drinking water supplies. Many of these solvents are carcinogenic and hazardous to health in general.
Although government, industry and the community at large are all relatively well informed to the dangers of toxic solvents, the dangers associated with the use of such solvents have not dramatically diminished their use. Safer handling, disposal, recycling, recovery and other responsible methods of dealing with toxic substances are improving. However, the availability of safer alternative solvents is still not wide spread, especially in second and third world countries, which is due, primarily, to the high cost of the solvent alternatives and because the majority of the environmentally safer solvent alternatives do not provide satisfactory performance.
In order for an “environmentally friendly” solvent alternative to gain wide spread acceptance, a solvent should meet several criteria. First, it should provide effective performance. Second, it should be economically viable and affordable. Third, it should be widely available and, of course, it should be non-toxic to the environment generally and humans specifically.
Several alternative solvents have been introduced by industry for decades, but in general do not meet the criteria stated above. Further, many of these solvents are not completely biodegradable, just less toxic.
A solvent described hereinafter provides high solvency performance while overcoming the toxicity issues associated with most other organic solvents. In addition, a contemplated solvent is biodegradable.
BRIEF SUMMARY OF THE INVENTION
The present invention contemplates an environmentally friendly ink removal solvent. This solvent is biodegradable in normal sewerage treatment plants, and has a low volatile content so that it can be used indoors with minimal ventilation.
The invention contemplates a composition comprising about 40 to about 70 weight percent of a C
1
-C
4
ester of lactic acid and about 1 to about 30 weight percent C
1
-C
4
ester of a C
16
-C
20
fatty acid having a melting point of −10° C. or less. In one embodiment of the invention, the composition also comprises about 10 to about 30 weight percent of an organic co-solvent; about 10 to about 30 weight percent of a surfactant; zero to about 5 weight percent of an acidulent; zero to about 10 weight percent of an emulsifying agent; and zero to about 5 weight percent of a fragrance.
In each of the embodiments of the invention, the particularly preferred C
1
-C
4
ester of lactic acid is the ethyl ester so that ethyl lactate is particularly preferred. The particularly preferred C
1
-C
4
ester of a C
16
-C
20
fatty acid is an ester of a mixture of oleic and linoleic acids. The methyl ester of a fatty acid is preferred; and the fatty acid mixture is preferably derived from an edible oil, with methyl soyate being particularly preferred.
Preferably, the organic co-solvent is a C
1
-C
4
ester of a C
3
-C
10
dicarboxylic acid. Preferably, the acidulent is citric acid. A preferred emulsifying agent is a C
12
-C
20
fatty acid mono- or di-glyceride or a mixture of mono- or di-glycerides.
The invention contemplates a method of removing ink that can be used for cleaning printing presses, blankets and rollers. A method of removing ink according to the invention comprising the steps of providing an ink removal solution, contacting a surface that has ink on it with the ink removal solution, and separating the used ink removal solution from the cleaned surface.
The ink removal solution comprises about 40 to about 70 weight percent of a C
1
-C
4
ester of lactic acid and about 1 to about 30 weight percent C
1
-C
4
ester of a C
16
-C
20
fatty acid having a melting point of −10° C. or less, as discussed above.
The contact with the ink removal solution is for a period of time sufficient to permit at least some of the ink to become dissolved or dispersed in the ink removal solution to form a used ink removal solution and a cleaned surface. That contact can be with a flushing motion, so that the contact and removal steps might occur at about the same time. That contact could also be with a rubbing motion, providing some friction to assist in ink removal.
The present invention has several benefits and advantages.
One benefit of the invention is that a contemplated composition is safer that halogenated organic solvent.
A related advantage is that a contemplated composition can be used in occupied areas. The characteristic odor from traditional ink
Douyon Lorna M.
Vertec Biosolvents, LLC
Welsh & Katz Ltd.
LandOfFree
Environmentally friendly ink cleaning preparation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Environmentally friendly ink cleaning preparation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Environmentally friendly ink cleaning preparation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2446544