WO2008106684A2

WO2008106684A2 - Coating removal composition

Info

Publication number: WO2008106684A2
Application number: PCT/US2008/055686
Authority: WO
Inventors: Charles A. Crawford; Lance D. Brown; Carmine Savaglio
Original assignee: Johnsondiversey, Inc.
Priority date: 2007-03-01
Filing date: 2008-03-03
Publication date: 2008-09-04
Also published as: US20120289446A1; WO2008106684A3; US8173586B2; EP2129728A2; US20080210265A1; US8778093B2; US20110166054A1

Abstract

The present invention is directed to a coating removal composition comprising at least one weak metal binding agent, a solvent system comprising at least one alcohol or ester, and a corrosion inhibition system. A method of removing a coating from an intentionally colored concrete floor is also disclosed.

Description

COATING REMOVAL COMPOSITION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Utility Application No. 11/712,774, filed March 1, 2007.

FIELD OF THE INVENTION

[0002] The present invention relates generally to a composition for removing floor coatings, in particular, it relates to products and methods suitable for the removal of coatings from concrete floors, decorative concrete floors and floors utilizing cementatious matrices, such as terrazzo. More specifically, this invention relates to a coating removal composition that is safe for intentionally colored concrete substrates, such as those that are dyed, stained or otherwise treated with pigments.

BACKGROUND OF THE INVENTION

[0003] Concrete presents many unique challenges in terms of its protection. Concrete is a relatively porous substrate that is inherently alkaline in nature. As such, it is highly reactive to acids and is easily, unintentionally stained or otherwise soiled. Likewise, concrete is relatively soft and prone to wear and deterioration. Coatings are often used to protect concrete from wear, unintentional staining or soiling and acid etching. These coatings must be somewhat tolerant to the alkaline nature of concrete, and as a result are typically more difficult to remove than traditional styrene/acrylate based floor coatings. Furthermore, intentionally colored concrete flooring presents a unique challenge from the perspective of coating removal compositions in that traditional compositions that are effective for coating removal may damage or discolor such flooring. This often results in permanent, unsightly damage and/or necessitates the recoloring of the concrete at significant cost. This is largely the result of the highly alkaline nature of the coating removal compositions and the presence of relatively strong chelating agents, such as EDTA, etc., attacking the metal based colorant component of the intentionally colored concrete.

[0004] It, has been common to treat such concrete surfaces with semi-permanent coatings, such as those utilizing epoxy or urethane technologies. These coating systems suffer from their lack of removability and repairability. Likewise, they often require highly skilled or trained installers due to the sensitive nature of the application and the potentially hazardous profile of the chemistry involved. Such semi-permanent coatings are also expensive. Unfortunately, use of conventional removable coatings, such as acrylic based coatings, which are more cost effective, less labor intensive and utilize less hazardous chemistry has not heretofore provided satisfactory results because of the need for repeated, regular removal/stripping and reapplication. Such repeated removal or stripping with traditional coating removal compositions results in further, more extensive damage to the color component of the concrete flooring substrate because of more frequent use. Thus, there are a significant number of limitations with prior art coatings. Additionally the results are often unsatisfactory, in particular for intentionally colored concrete flooring, wherein the color is significantly diminished, discolored or entirely removed.

[0005] Previously, removal of coatings from decorative concrete substrates has been complicated due to the sensitive nature of the substrate to traditional chemistries used in coating removal compositions. Currently, coating removal compositions for intentionally colored or stained, decorative concrete are based on solvent systems that resemble heavy duty paint stripping products. These products prevent the displacement of metal ions that give the concrete its colorful look. The result of not using a product that is safe for color is gray concrete. Typically, such prior art coating removal compositions "safe" for colored concrete contain a blend of chemicals such as; N-methyl pyrolidone, methyl ethyl ketone, alkylene carbonates, dibasic ester mixtures, etc. These chemistries are undesirable for larger areas of removal, are difficult to work with, and potentially harmful if contact or inhalation has occurred. Clearly, a significant number of drawbacks are associated with prior art colored concrete coating coating removal compositions.

[0006] In summary, a considerable number of deficiencies exist in the art relating to the coating of concrete substrates and the subsequent removal of those coatings. This is particularly true in the case of intentionally colored, decorative concretes.

[0007] Accordingly, it is an object of the present invention to provide a coating removal composition wherein said composition provides good performance on the removal of coatings while reducing the damage such compositions impart to intentionally dyed, stained or pigmented substrates, such as decorative concrete. In particular, there is a need for an improved coating removal composition, which overcomes the shortcomings of the compositions of the prior art. SUMMARY OF THE INVENTION

[0008] One aspect of the present invention provides a composition for removing floor coatings from cementatious, stone or concrete substrates. The coating removal compositions comprise at least one weak metal binding agent, a solvent system comprising at least one alcohol or ester, and a corrosion inhibition system.

[0009] The invention also relates to a method of removing a coating from an intentionally colored concrete floor. The method involves applying a coating removal composition to an intentionally colored concrete floor, where the colored concrete floor has a colorant component. The coating removal composition is allowed to remain on the floor for a period of time and is then removed from the floor. In one embodiment, such method results in the intentionally colored concrete floor retaining at least about 70% of the colorant component.

BRIEF DESCRIPTION OF THE DRAWING

[0010] Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings.

[0011] FIGURE 1 is a picture of intentionally colored concrete tiles subjected to prior art and inventive coating removal compositions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0013] It also is understood that any numerical range recited herein includes all values from the lower value to the upper value. For example, if a concentration range is stated as 1% to 50%, it is intended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expressly enumerated in this specification. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application.

[0014] The present invention is directed to compositions for removing coatings from substrates, such as cementatious, natural stone or concrete substrates, particularly those concrete substrates t having a colorant component therein or thereon. A colorant component can be any ink or pigment that is dispersed in the substrate to alter the natural color of the substrate. The colorant component is often added as a metallic salt (typically a transition metal salt or transition metal complex) that reacts with the substrate. The coating removal compositions of the present invention include at least one weak metal binding agent, a solvent system comprising at least one alcohol or ester, and a corrosion inhibition system.

[0015] The inventive compositions have been found to be less damaging to concrete floors or flooring substrates having a colorant component. Utilization of the inventive composition results in a significant reduction in damage, discoloration, or removal of the colorant component than prior art compositions Loss or reduction of color is just that, a loss of the visible color, hi terms of damage and discoloration, damage and discoloration of intentionally colored substrates are evident by a visible change in the appearance of the substrate or a perceivable shift in the color thereof after treatment with coating removal compositions of the prior art. This can, for example, result from interactions of various compositional components with the metal-based complexes used to impart color. It is theorized that strong metal binding agents, such as EDTA, bind to such metals resulting in a shift in the absorbance characteristics of the pigment and thus a shift in visible color. In some cases, the damage can be as severe as leaching of the metal from the substrate. FIGURE 1 shows the reduction in color removal of intentionally colored concrete by utilization of the inventive compositions compared to prior art coating removal compositions.

[0016] The coating removal compositions of the present invention include a weak metal binding agent. Such weak metal binding agents include those that exhibit stability constants of less than about 11 (as described, for example, in "Metal Complexes in Aqueous Solutions", by Martell and Hancock, Plenum Press, 1996, incorporated by reference herein) or would be predicted by those skilled in the art to exhibit such properties based upon the steric, electronic and aqueous physicochemical properties of the material. Such weak metal binding agents include ethoxylated amines. Suitable ethoxylated amines include primary and secondary ethoxylated amines, such as those having one of the following formulae: (CH₂CH₂O)_xH

R-N R⁵R¹⁷N-(CH₂CH₂O)_xH

^ (CH₂CH₂O)_n.xH

I II

(CH₂CH₂O)_xH

(C₂H₂₂₊₁VO-(C^)-N

^ (CH₂CH₂O)_n.xH

III

where R, R' and R" are independently C3-C26 alkyl, C3-C26 aryl or C3-C26 alkyl ether groups wherein y is an integer from 2 to 10, z is an integer from 1 to 20, such that y + z = 6 to 26, x is an integer from 1 to 15 and n is an integer from 1 to 25.

[0017] Suitable weak metal binding agents include, but are not limited to, bis-(2- hydroxyethyl) isodecyloxypropylamine, poly (5) oxyethylene isodecyloxypropylamine, bis- (2-hydroxyethyl isodecyloxypropylamine, poly (5) ) oxyethylene isotridecyloxypropyl amine, bis-(2-hydroxyethyl) linear alkyloxypropylamine, bis (2-hydroxyethyl) soya amine, poly (15) oxyethylene soya amine, bis (2-hydroxyethyl) octadecylamine, poly (5) oxyethylene octadecylamine, poly (8) oxyethylene octadecylamine, poly (10) oxyethylene octadecylamine, poly (15) oxyethylene octadecylamine, bis (2-hydroxyethyl) octadecyloxypropylamine, bis-(2-hydroxyethyl) tallow amine, poly (5) oxyethylene tallow amine, poly (15) oxyethylene tallow amine, poly (3) oxyethylene 1,3 diaminopropane and bis (2-hydroxyethyl) coco amine and combinations thereof.

[0018] hi some embodiments, the weak metal binding agent comprises about 0.5 to about 25.0 weight percent of the coating removal composition. In other embodiments, the weak metal binding agent is about 3.0 to about 15.0 weight percent of the coating removal composition. In still further embodiments, the weak metal binding agent is about 5.0 to about 10.0 weight percent of the coating removal composition.

[0019] Solvent systems of the present invention include at least one alcohol or ester.

Suitable alcohols include polyhydric alcohols, aromatic alcohols and mono or linear alcohols. Suitable esters include benzoates and dibenzoates. Optionally, phthalates or pyrrolidone based solvents may be utilized in some embodiments of the present invention. Blends of the various alcohols and esters have also been found to be useful in the solvent system. [0020] Such a solvent system acts to help dissolve, penetrate and emulsify the coating. Further, it is believed that the solvent system enhances the activity of the other components by enhancing permeation of the materials into the coating film, such as corrosion inhibitors, inorganic alkaline salts, etc. They additionally enhance the performance of products by keeping the composition "wet" on the surface of the substrate. Such a solvent system acts as a carrier and assists in dissolving, emulsifying the coating or swelling and penetrating the coating until it is fully removed from the surface.

[0021] Suitable polyhydric alcohols include, but are not limited to, t alkane polyols having from 2-6 carbon atoms and from 2-3 hydroxyls . Examples of suitable polyhydric alcohols include ethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,2- butanediol, 1 ,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2 -propanediol, 1,5-pentanediol, meso-erythritol, neopentyl glycol, pentaerythritol, and blends thereof.

[0022] Suitable aromatic alcohols include benzyl alcohol, xylenol, phenol, etc.

[0023] Additionally, mono alcohols such as methanol, ethanol, propanol, isopropanol and butanol can be utilized.

[0024] Alternatively, the solvent system may include an ester. Suitable esters include glycol ether dibenzoates based on ethylene or propylene glycol including but not limited to propylene glycol dibenzoate, dipropylene glycol dibenzoate, polypropylene glycol dibenzoate, ethylene glycol dibenzoate, diethylene glycol dibenzoate, polyethylene glycol dibenzoate, neopentyl glycol dibenzoate, and the like as well as isodecyl benzoate, dipropylene glycol monomethyl ether benzoate, 2,2,4-trimethyl-l,3-pentanediol diisobutyrate.

[0025] The solvent system optionally contains one or more suitable solvents in addition to the ester or the alcohol. Exemplary solvents include but are not limited to glycol ether based solvents based on ethylene or propylene glycol such as ethylene glycol, propylene glycol, diethylene glycol ethyl ether, dipropylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, ethylene/diethylene glycol 2-ethylhexyl ether, ethylene glycol phenyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, propylene glycol phenyl ether, and blends thereof. Phthalate based solvents including, but not limited to, dibutyl phthalate, butyl benzyl phthalate, diethyl phthalate, and combinations thereof may also be used. Further, optionally the solvent system can include pyrrolidone based solvents such as 2-pyrrolidone, N-methyl-2- pyrrolidone, N-octyl-2-pyrrolidone, N-dodecyl-2-pyrrolidone, and the like. [0026] The solvent system can also optionally include water. Combinations of these various solvent components may be utilized.

[0027] The solvent system comprises about 0.50 to about 98.5 weight percent of the coating removal composition, hi some embodiments, the solvent system comprises about 10.0 to about 80.0 percent of the coating removal composition, hi some embodiments, the solvent system is about 20.0 to about 50.0 weight percent of the coating removal composition.

[0028] The coating removal compositions also include a corrosion inhibition system.

Such a corrosion inhibition system is useful in mitigating and/or minimizing damage and/or color loss to the concrete substrate that is being treated, in particular, intentionally colored, dyed, stained or pigmented concretes having a colorant component therein or thereon.

[0029] Typically, the corrosion inhibition system includes heterocyclic organic materials, where the heteroatom can include but is not limited to elements of groups V and/or VI, such as N, P, As, Sb, O, S, Se or Te. These elements can be a part of an aromatic system comprised of 4 to about 18 atoms, with approximately 1 to 6 heteroatoms present. Suitable heterocyclic organic materials include azoles, mercaptans, furans and combinations thereof. Suitable mercaptans such as 2-mercaptobenzothiazole, sold under the trademark ROTAX and are available from Rt. Vanderbilt Company, Inc., of Norwalk, Connecticut. Suitable azoles include Cobratec PT, Cobratec TT-505C,Cobratec TT-85, Cobratec TT-100 and Cobratec 99. Cobratec 35-G from PMC Specialties Group, Inc., Div. of PMC, Lie. Such a corrosion inhibition system provides a coating removal composition which exhibits no corrosive or minimal corrosive activity toward substrates which are being stripped of coating, in particular, intentionally colored or pigmented concretes having a colorant component. Suitably, use of a coating removal compositions results in a used coating removal composition with an absorbance reading of less than about 0.05, when measured according to the methods described in the examples.

[0030] Such a corrosion inhibition system is present in an amount of about 0.05 to about 25.0 weight percent of the coating removal composition, hi some embodiments, the corrosion inhibition system comprises about 0.50 to about 15.0 weight percent of the composition, hi alternative embodiments of the coating removal compositions, the corrosion inhibition system is present in about 1.0 to about 10.0 weight percent of the coating removal composition. Still other embodiments include about 2.0 to about 5.0 weight percent of the coating removal composition. [0031] In some embodiments the ratio of weak metal binding agent to corrosion inhibition system is about 1 :1 to about 1:50 or about 1 :2 to about 1:20. In other embodiments of the coating removal composition, the ratio of weak metal binding agent to corrosion inhibition system is about 1 :4.

[0032] The inventive composition may also optionally include at least one inorganic alkaline salt. Inorganic alkaline salts suitable for use can include lithium carbonate, potassium carbonate, sodium carbonate, lithium hydroxide, potassium hydroxide, sodium hydroxide, lithium silicates, sodium silicates, potassium silicates, lithium phosphates, sodium phosphates, potassium phosphates, and combinations thereof. All forms of such salts are suitable for use including various hydration grades, mono-, di-, tri-, ortho- and pyro-forms. Additional useful inorganic alkaline salts include citrates, and polyphosphates, e.g. sodium tripolyphosphate and sodium tripolyphosphate hexadydrate, potassium tripolyphosphate and mixed sodium and potassium tripolyphosphate salts; and partially water-soluble or insoluble salts such as crystalline layered silicates (EP-A-0164514 and EP-A-0293640) and aluminosilicates inclusive of Zeolites A, B, P, X, HS and MAP. In one embodiment it has been found useful to utilize potassium hydroxide. Potassium hydroxide can be utilized in various forms including a 45 percent solution, solid pellet and flakes, as can other inorganic alkaline salts.

[0033] Such salt typically comprises about 0.10 to about 20 weight percent of the coating removal composition. In some embodiments, the inorganic alkaline salt is about 0.10 to about 10 weight percent of the composition. In some embodiments of the compositions, such salts are present at about 1.0 to about 2.0 weight percent.

[0034] The inventive coating removal composition may also optionally include at least one source of organic alkalinity, suitably an organoamine derivative, an organoamine derivative with a monoethanolamine, triethanolamine, monoisopropanalamine, diesoproanolamine, triisopropanolamine, and other organomine derivatives known to one of ordinary skill in the art.

[0035] Further, the coating removal compositions may also optionally include surfactants in varying amounts which improve surface wetting and rinseability of the product in the early and later stages of the coating removal process, reduce the impact of foam and may assist in the emulsification of the floor coating to be removed. Such attributes are improved because such surfactants lower surface tension and increase wetability. Various anionic, nonionic and amphoteric surfactants have been found useful in the coating removal compositions of the present invention. Surfactants useful in the present invention are limited only in their ability to provide sufficient wetting characteristics for the coating removal process while exhibiting an acceptable foam profile. Thus, aqueous coating removal compositions of the present invention may include, for example, surfactants such as organosulfates, organosulfonates, mono and diester organosulfo succinates, organophosphates, polysiloxanes, polyether modified polysiloxanes, acetylene based surfactants and nonionic surfactants.

[0036] Suitable nonionic surfactants can be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxy alkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements. Additional nonionic surfactatns can be selected from the class of fiuorinated materials, such Zonyl, FSJ, Zonyl FSN, etc., commercially available from DuPont. Additional surfactants that may be added include the alkali metal and amine salts of higher fatty acids having, for example, 12 to 18 carbon atoms such as salts of tall oil fatty acid.

[0037] Suitable anionic surfactants can be broadly described as the water-soluble salts, particularly the alkali metal salts, of organic sulfur reaction products having in their molecular structure an alkyl radical containing from about 8 to about 22 carbon atoms and a radical selected from the group consisting of sulfamic acid and sulfuric acid ester radicals. Such surfactants are well known in the art and are described at length in "Surface Active Agents and Detergents^'", Vol. II by Schwartz, Perry and Berch, Interscience Publishers Inc., 1958, incorporated by reference herein.

[0038] Suitable amphoteric surfactants can be broadly described as those surfactants that have the ability to exhibit anionic, cationic or zwitterionic functionality and whose overall properties are pH dependent. Classes of amphoteric surfactants includes, but is not limited to, betaines, hydroxy sultaines, amine oxides, amphocarboxylates, amphodicarboxylates, alkylammocarboxylates, alkylaminodicarboxylates, polyamines and the like.

[0039] In one embodiment of the inventive composition the surfactants are about 0.25 to about 10.0 weight percent of the coating removal composition. In some embodiments of the inventive composition, the surfactants are about 1.0 to 8.0 weight percent of the coating removal composition. In some embodiments of the inventive composition, the surfactants are about 2.0 to about 5.0 weight percent of the coating removal composition.

[0040] The inventive coating removal composition may also optionally include at least one coupling agent, or hydrotrope. Coupling agents assist in providing stability to the resulting coating removal composition. Coupling agents present in the inventive composition include fatty acid salts, aromatic sulfonate derivatives, phosphate esters or mixtures thereof. In some embodiments of the inventive composition, sodium xylene sulfonate is about 1 to about 20 weight percent of the inventive composition, hi one embodiment, sodium xylene sulfonate is about 2 to about 5 weight percent of the inventive composition.

[0041] Such coating removal compositions have been found to effectively remove coatings from cementatious, stone or concrete substrates or surfaces. Of particular benefit is that the inventive composition is non-damaging or imparts little damage to decorative concrete substrates. This is particularly the case for those concretes that are intentionally dyed, stained, colored or pigmented,

[0042] The coating removal compositions are applied to such coated substrates to be stripped by any number of techniques including, for example, mopping, pouring, spraying, sprinkling, brushing, immersing, etc. the inventive coating removal composition onto the coated substrate, such as concrete, to be treated or stripped. The coating removal composition is then allowed to remain on the surface for a period of time. Typically, the coating removal composition can be applied to the surface and left to stand in contact with the surface for a period of about 5-30 minutes, however longer or shorter periods of time are possible. After such time, the coating removal composition is removed from the surface along with the emulsified coating by any number of methods known to one of ordinary skill in the art including mopping, spraying, using an automatic scrubber, vacuuming, or flushing with water, etc. The thus treated cementatious or concrete substrate is then allowed to dry.

[0043] In some embodiments, the intentionally colored concrete retains at least about

70% of the colorant component after utilizing the coating removal composition to remove a coating or finish therefrom. In some embodiments, the intentionally colored concrete retains at least about 80% of the colorant component. In other embodiments, the intentionally colored concrete floor retains at least about 90% of the colorant component. In still other embodiments, the intentionally colored concrete floor retains at least about 95% of the colorant component. In other embodiments, the intentionally colored concrete floor retains at least about 99% of the colorant component. EXAMPLES

[0044] In preparing examples of the coating removal compositions, the following steps are used.

[0045] A vessel was charged with an appropriate amount of deionized water. With agitation, an appropriate amount of Dowanol Butyl cellosolve was added. With agitation, an appropriate amount of Benzyl Alcohol was then added to solution. With agitation, an appropriate amount of Rhodia Mirataine JCHA was added to solution. With agitation, an appropriate amount of Dupont Zonyl FSO was added to solution. With agitation, an appropriate amount of Potassium Hydroxide (45% solution) was then added to the solution. With agitation, an appropriate amount of Cobratec 35-G or Tomah E-14-5 was then added to solution. With agitation, an appropriate amount of Sodium Xylene Sulfonate (40% solution) was then added. The mixture was then agitated for 10 minutes.

[0046] The following coating removal compositions, Examples 1-3 of Table 1 were prepared and evaluated.

Table 1

[0047] These Example compositions 1-3 and several commercially available coating removal compositions were evaluated for performance using a modified ASTM D 1792-82 as follows: [0048] A vinyl composition tile was utilized for each evaluation. This tile was coated with Signature floor finish from JohnsonDiversey, Inc., Sturtevant, WI as outlined in the ASTM. Ten coats of finish were applied. The coating removal compositions evaluated were the Examples 1-3 and prior art compositions from Betco Corp. of Toledo, OH; AmSan of Pompano Beach, FL; Buckeye International, JohnsonDiversey, Inc. of Sturtevant, WI and the ASTM Standard Stripper from ASTMD 1792-82.

[0049] For removability evaluation, 30 grams of 1:1 dilution (coating removal composition to water) was added to the apparatus. After 5 minutes of dwell time, the motor was started for one cycle. The number of oscillations required to remove each coat of finish and the total number of oscillation cycles required to remove all coats of finish was then recorded. (The total number is shown in Table 2.) The ranking system of ASTM D 1436 was used to assess performance. The results are found in Table 2.

[0050] To evaluate color removal or affect on the colorant component of intentionally colored concrete by a coating removal composition, the following method was utilized. The inventive compositions and prior art compositions were evaluated as follows:

[0051] Into a 50OmL large mouth jar was inserted one Fern Green (CS-I l) concrete block with stain applied sample tile (approx. 5cm x 4cm) from the Lithochrome Chemstain series (ex. Scofield). To the jar was added IuOmL of the coating removal composition to be tested. After standing for 3 hours, a 1.5mL sample of the coating removal composition was removed from the jar and analyzed by UV/vis spectroscopy ("spent coating removal composition"). Fresh, unused, unspent coating removal composition was used as a control for comparison of the absorbance. The absorbance was measured from 360 to 1100 nm utilizing UV-VIS spectroscopy. Overall, compositions of the present invention exhibit absorbance readings of less than 0.05 (utilizing a 1 cm pathlength polyethylene cell) in the wavelength range of 360 to 1100 nm. The results of such evaluations are found in Table 2.

TABLE 2

[0052] While various embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with one of ordinary skill in the art without departing from the invention in its broader aspects. Various features of the invention are defined in the following claims.

Claims

We Claim:

1. A coating removal composition comprising: a) at least one weak metal binding agent; b) a solvent system comprising at least one alcohol or ester, and c) a corrosion inhibition system.

2. The coating removal composition of Claim 1, wherein the weak metal binding agent is an ethoxylated amine.

3. The coating removal composition of Claim 2, wherein the weak metal binding agent is a primary or secondary ethoxylated amine.

4. The coating removal composition of Claim 2, wherein the ethoxylated amine is selected from the group consisting of

(CH₂CH₂O)_xH R N

(C H₂CH₂OV_XH ₅

R¹R¹¹N (CH₂CH₂O)_xH ₅

and

(CH₂CH₂O)_xH

(C_zH_2z+1)-O-(C_yH_2y)-N

(CH₂CH₂OV_xH _}

wherein R, R' and R" are independently C3-C26 alkyl, C3-C26 aryl or C3-C26 alkyl ether groups; and wherein y is an integer from 2 to 10, z is an integer from 1 to 20, such that y + z = 6 to 26, x is an integer from 1 to 15 and n is an integer from 1 to 25.

5. The coating removal composition of Claim 1, wherein the weak metal binding agent is selected from the group consisting of bis-(2-hydroxyethyl) isodecyloxypropyl amine, poly (5) oxyethylene isodecyloxypropylamine, bis-(2- hydroxyethyl isodecyloxypropylamine, poly (5) ) oxyethylene isotridecyloxypropyl amine, bis-(2-hydroxyethyl) linear alkyloxypropyl amine, bis (2-hydroxyethyl) soya amine, poly (15) oxyethylene soya amine, bis (2-hydroxyethyl) octadecylamine, poly (5) oxyethylene octadecylamine, poly (8) oxyethylene octadecylamine, poly (10) oxyethylene octadecylamine, poly (15) oxyethylene octadecylamine, bis (2- hydroxyethyl) octadecyloxypropylamine, bis-(2-hydroxyethyl) tallow amine, poly (5) oxyethylene tallow amine, poly (15) oxyethylene tallow amine, poly (3) oxyethylene 1,3 diaminopropane and bis (2-hydroxyethyl) coco amine and combinations thereof.

6. The coating removal composition of Claim 1, wherein the weak metal binding agent comprises about 0.5 to about 25.0 weight percent of the composition.

7. The coating removal composition of Claim 6, wherein the weak metal binding agent comprises about 3.0 to about 15.0 weight percent of the composition.

8. The coating removal composition of Claim 6, wherein the weak metal binding agent comprises about 5.0 to about 10.0 weight percent of the composition.

9. The coating removal composition of Claim 1 , wherein the at least one alcohol is a polyhydric alcohol.

10. The coating removal composition of Claim 9, wherein the polyhydric alcohol comprises an alkane polyol having from 2 to 6 carbon atoms and from 2 to 3 hydroxyl groups.

11. The coating removal composition of Claim 10, wherein the polyhydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,2-butanediol, 1,3-butanediol, 1 ,4-butanediol, 2,3-butanediol, 1,2- propanediol, 1,5-pentanediol, meso-erythritol, neopentyl glycol, pentaerythritol, and blends thereof.

12. The coating removal composition of Claim 1, wherein the at least one alcohol comprises an aromatic alcohol.

13. The coating removal composition of Claim 12, wherein the aromatic alcohol is selected from the group consisting of benzyl alcohol, xylenol, and phenol. 14. The coating removal composition of Claim I₅ wherein the at least one alcohol comprises a mono alcohol.

14. The coating removal composition of Claim 1, wherein the ester is selected from the group consisting of propylene glycol dibenzoate, dipropylene glycol dibenzoate, polypropylene glycol dibenzoate, ethylene glycol dibenzoate, diethylene glycol dibenzoate, polyethylene glycol dibenzoate, neopentyl glycol dibenzoate, isodecyl benzoate, dipropylene glycol monomethyl ether benzoate, 2,2,4-trimethyl-l,3- pentanediol diisobutyrate and blends thereof.

15. The coating removal composition of Claim 1, wherein the solvent system comprises about 0.50 to about 98.5 weight percent of the composition.

16. The coating removal composition of Claim 15, wherein the solvent system comprises about 10.0 to about 80.0 weight percent of the composition.

17. The coating removal composition of Claim 15, wherein the solvent system comprises about 20.0 to about 50.0 weight percent of the composition.

18. The coating removal composition of Claim 1, wherein the corrosion inhibition system comprises a heterocyclic organic material.

19. The coating removal composition of Claim 18, wherein the heterocyclic organic material is selected from the group consisting of azoles, mercaptans, furans and combinations thereof.

20. The coating removal composition of Claim 1, wherein the corrosion inhibition system comprises about 0.05 to about 25.0 weight percent of the composition.

21. The coating removal composition of Claim 1, further comprising an inorganic alkaline salt.

22. The coating removal composition of Claim 21, wherein the inorganic alkaline salt is selected from the group consisting of lithium carbonate, potassium carbonate, sodium carbonate, lithium hydroxide, potassium hydroxide, sodium hydroxide, lithium silicates, sodium silicates, potassium silicates, lithium phosphates i, sodium phosphates, potassium phosphates, and combinations thereof.

23. The coating removal composition of Claim 22, wherein the inorganic alkaline salt comprises about 0.05 to about 25.0 weight percent of the composition.

24. The coating removal composition of Claim 23, wherein the inorganic alkaline salt comprises about 0.50 to about 15.0 weight percent of the composition.

25. The coating removal composition of Claim 23, wherein the inorganic alkaline salt comprises about 1.0 to about 10.0 weight percent of the composition.

26. The coating removal composition of Claim 23, wherein the inorganic alkaline salt comprises about 2.0 to about 5.0 weight percent of the composition.

27. The coating removal composition of Claim 1, wherein the ratio of weak metal binding agent to corrosion inhibition system is about 1 :4.

28. A method of removing a coating from an intentionally colored concrete floor comprising: a) applying a coating removal composition according to claim 1 to an intentionally colored concrete floor, said colored concrete floor having a colorant component and coating; b) allowing said coating removal composition to remain on the floor for a period of time; and c) removing the composition and coating from the floor, wherein the intentionally colored concrete floor retains at least about 70% of the colorant component.

29. The method of Claim 28, wherein the intentionally colored concrete retains at least about 80% of the colorant component.

30. The method of Claim 28, wherein the intentionally colored concrete floor retains at least about 90% of the colorant component.

31. The method of Claim 28, wherein the intentionally colored concrete floor retains at least about 95% of the colorant component.

32. The method of Claim 28, wherein the intentionally colored concrete floor retains at least about 99% of the colorant component.