CA2242912A1 - Thermally releasable barrier coating, composition therefor, and use thereof - Google Patents
Thermally releasable barrier coating, composition therefor, and use thereof Download PDFInfo
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- CA2242912A1 CA2242912A1 CA002242912A CA2242912A CA2242912A1 CA 2242912 A1 CA2242912 A1 CA 2242912A1 CA 002242912 A CA002242912 A CA 002242912A CA 2242912 A CA2242912 A CA 2242912A CA 2242912 A1 CA2242912 A1 CA 2242912A1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/32—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof from compositions containing microballoons, e.g. syntactic foams
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D131/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid, or of a haloformic acid; Coating compositions based on derivatives of such polymers
- C09D131/02—Homopolymers or copolymers of esters of monocarboxylic acids
- C09D131/04—Homopolymers or copolymers of vinyl acetate
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D1/00—Processes for applying liquids or other fluent materials
- B05D1/32—Processes for applying liquids or other fluent materials using means for protecting parts of a surface not to be coated, e.g. using stencils, resists
- B05D1/322—Removable films used as masks
- B05D1/327—Masking layer made of washable film
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D3/00—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
- B05D3/02—Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
- C09D133/24—Homopolymers or copolymers of amides or imides
- C09D133/26—Homopolymers or copolymers of acrylamide or methacrylamide
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
- C09D5/008—Temporary coatings
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/14—Polymer mixtures characterised by other features containing polymeric additives characterised by shape
- C08L2205/18—Spheres
- C08L2205/20—Hollow spheres
Abstract
A combination of (A) a nitrogen containing water soluble polymer, (B) a water insoluble film forming polymer, and (C) gas filled, polymer walled microballoons provides a superior thermally releasable coating that (i) can be conveniently and reliably coated from a water based solution and dispersion onto surfaces to be protected against painting, (ii) is reliably stable at ambient temperatures, (iii) even after being coated with many times its own thickness of accumulated paint particles, rapidly disintegrates, along with the accumulated paint coating formed on it, upon contact with hot water, into particles of a size that readily escapes from standard paint booth grate structures, (iv) detackifies any paint particles that escape during disintegration of the combined thermally releasable coating and paint residues accumulated thereon, and (v) disintegrates into particles that float on water, so that they can be readily removed from the grates by immersing the latter in hot water, allowing a few minutes for the disintegration to take effect, and then skimming off the floating solids on the surface of the water.
Description
. CA 022429l2 l998-07-lO
W O 97/27241 PCTrUS97/00007 THERMALLY RELEASABLE BARRIER COATING, COMPOSITION
THEREFOR, AND USE THEREOF
Field of the Invention This invention relates to an improved composition and method for providing a tht-rm~lly releasable barrier coating for surfaces not intPn~le~1 to be painted but on which paintl nevertheless accnm~ tçs in practice because of the proximity of the ~urf~es not 5 inten~ l to be painted to other snrf~cçs that are intenflecl to be p~intçd The invention is more particularly applicable for coating the floor grates in paint spray booths or cabin-ets, such as are extensively used in mz~nllfslrturing automobiles and many other objects ti~at are decorated by p~inting Discussion of Related Art Numerous barrier coatings have been used in the prior art. Most have been re-moved when n~cec~7~1y by solvents, use of high ~les~ andlor high temperature water, mPrh~nic~l means, or the like, all of which to greater or lesser degrees are labor intens-iveS requ~re substantial volumes of at least moderately expensive materials, or both.
More recently, therm~lly removable barrier coatings have become known in the art.
Throughout this description, unless the context requires to the contrary, as where a specific m~tçri~l is named, the term "paint" is to be understood as encomp~ing all simi}ar terms such as enamel, lacquer, shellac, varnish, and the like.
WO 97127241 PCT~US97/00007 Most of those so far known utilize a combination of carbonate and/or acid carbonate salts with an acidic material that is prevented from coming into contact with the carbonate even when mixed with it at normal ambient temperatures, but that is brought into contact by some merhRnical and/or chemical means when the temperature of the solid co.~ g both components is raised, most often by contact with hot water and/or steam. The re-sulting reaction between acid and carbonate generates carbon dioxide gas that causes the coating to rupture and in principle to fall off the coated surface, or at least to become re-movable by light mechanical action.
These thermally removable barner coatings have fiimini~hed the labor and/or ma-10 terial costs compared with those of previous methods of removing protective barriercoRtin~s but in practice have been found to have certain difficulties: Complete removal is sometimes not reliably achieved; the paint Rcc~-mlllRtl-d on the barrier coating surface often becomes ~letRrh~l during the removal process, so that it can redeposit on the surface int~n~1e~ to be protected from being coated with it; pieces of the coating after 15 release can all too readily become trapped in the structure having the surface to be protected from paint, particularly when this structure has relatively narrow spacings be-tween solid elements, as is true in the grates conventionally used in paint spray booths;
and the internal barrier materials that prevent contact between carbonate ions and acid materials at ambient tempeldlul.,s can become unstable or otherwise suffer faults that 2a cause p~emature removal and/or unreliable or incomplete removal when desired. nESCRlPTION OF THE INVENTION
Ob~ects of the Invention A major object of the invention is to provide a new type of th~nRlly releasable b~ier coating that will overcome or at least ameliorate some or all of the problems with 25 prior art th~rmRlly releasable barrier coRtin~ as described above. Other objects will be a~ l from the description below.
General lPrinciples of Description Except in the claims _nd the specific ~rRmples, or where otherwise expressly in-dicated, all m-m.ori~ RI ~ lRntifies in this description indicating amounts of material or con-ditions of reaction and/or use are to be understood as modified by the word "about" indescribing the broadest scope of the invention. Practice within the numerical limits stat-ed is ~nerRlly pl~,r~llcd, however. Also, unless expressly stated or nece~isalily implied CA 02242912 1998-07-lO
by the context to the contrary: percent, "parts of", and ratio values are by weight; the term "polymer" includes "oligomer", "copolymer", "terpolymer", and the like; the first definition or description of the m~ning of a word, phrase, acronym, abbreviation or the like applies to all subsequent uses of the same word, phrase, acronym, abbreviation or the like and applies, mutatis mutandis, to normal grammatical variations thereof; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the mem-bers of the group or class are equally suitable or preferred; specifications in chemical terms of materials in compositions refers to the m~ten~l~ at the time of addition to any 10 composition so specified, and does not necessarily exclude the possibility of reaction between such materials with other materials already present in the composition at the time of addition of the specified materials; specification of materials in ionic form im-plies the ~les~"ce of sufficient counterions to produce electrical neutrality for the compo-sition as a whole; and any counterions thus implicitly specified preferably are selected from among other constituents explicitly specified in ionic form, to the extent possible;
otherwise such counterions may be freely selected, except for avoiding counterions that act adversely to the objects of the invention.
Summary of the Invention It has been discovered that a combination of (A) a nitrogen co. ~ ; . .g water solu-ble polymer, (B) a water insoluble film forming polymer, and (C) gas filled, polymer walled microballoons provides a superior th~.rrn~lly releasable coating that, at least in its most ~ r~,l..,d embodiments, (i) can be conveniently and reliably coated from a water based solution and dispersion onto surfaces to be protected against p~inting, (ii) is reliab-ly stable at ambient telllp~ldtures, (iii) even after being coated with many times its own thirl~n~ of accl-m~ tec~ paint particles, rapidly ~ int~ tes, along with the ~ccl~mlllS-t-ed paint coating formed on it, upon contact with hot water, into particles small enough that they readily escape from standard paint booth grate :iLlu-;Lul~;;s,(iv) normally detacki-fies any initially tacky paint particles that might escape during ~ tintPgration of the com-bined ~h~rrn~lly releasable coating and paint residues ~ccl-m~ te~l thereon, and (v) dis-i~ Les into particles that fioat on water, so that they can be readily removed from thegrates by imme.r.~ing the latter in hot water. allowing a few minutes for the disintegration to take effect, and then skimming of the floating solids on the surface of the water.
. CA 02242912 1998-07-lO
W O97/27241 PCTrUS97/00007 A polymer is defined as "film forming" for the purposes of this description if, when a solution or suspension of the polymer in water is dried at a tem~,.dLIlre of at least 25~ C from a liquid film thickness not greater than 1 millimet~?r, a continuous and coher-ent film that is solid at 25~ C is produced.
One major embodiment of the invention is a suitable liquid coating composition for applying a th~?rm~lly releasable barrier coating, the liquid coating composition com-prising, preferably consisting essentially of, or more preferably consisting of, water and:
(~) a component of water soluble polymer m~ri~1 that (i) is solid at 25 ~C, (ii) con-tains at least, with illcle~illg ~rer~.~,.lce in the order given, 1, 2, 4, 7, 10, 13, 15, 17, or 18.0 percent of nitrogen atoms bonded into a chemical moiety selected from the group con-cict;ng of amido and c~ l y ammoniurn moieties, and (iii) is soluble in water to an extent of at least 5 % at 25 ~C and normal atmosphericpressure;
(B) a component of film forming polymer that is not soluble in water to an extent of as much as 4.5 % at 25 ~C and norrnal atmospheric pressure but is stably dis-persed in the coating composition; and;
~C~ a component of gas filled, polymer walled microballoons having the ~10~eL lies that (i) they are stably di~ersed in the coating composition and remain stably dis-persed and subst~nti~lly une~cr~n-lf?d when the coating composition is m~
at a temperature not greater than 65 ~C; and (ii) when exposed for at least five5 to at least one tel~ a~ ; in the range from 80 to 95 ~C, they undergo an h~ev~l~,ible expansion, without wall rupture, so as to produce an e~r~nLl~d form which has a density not greater than 0.5 times their density before having ç~rr~ntl~l, and, optionally, one or more of the following colll~onents:
a coll-~on~llL of viscosity modifying agent(s) that are not part of any of the previ-ously recited components;
~) a component of solid filler that is not part of any ol: the previously recited com-ponents;
~F~ a component of dispersing agent that is not part of any of the previously recited 31) components;
~G) a component of pH adJusting agent and/or corrosion inhibitor that is not part of any of the previously recited components;
CA 02242912 1998-07-lO
W O 97/27241 PCTrUS97/00007 ~H) a component of coloring agent that is not part of any of the previously recited components; and (J) a component of biocide that is not part of any of the previously recited compon-ents, said liquid coating composition having the properties that it can be formed into a liquid coating over a solid subskate surface and that the thus-formed liquid coating can be con-verted, by heating the liquid film in place on the substrate to a temperature not greater than 65 ~C under normal atmospheric pressure for a time not greater than one hour, into a coherent continuous solid coating that adheres to the ~,u~ ale .
Another embodirnent ofthe invention is a process comprising, preferably consist-ing e~senti~lly of, or more preferably consisting of, the steps of:
(I) forming on a substrate surface to be protected against accumulation of paint thereon a liquid coating of a liquid coating composition according to the inven-tion as described above, said liquid coating having a thickness corresponding toat least a thickness of 12 micrometres (h~ ,hla~l~;r usually abbreviated as ",~Lm"~
of cc-n~titu~nt~ of the liquid coating composition that remain present after the li-quid coating is heated to 65 ~C~ for at least one hour; and (II) drying the liquid coating forrned in step (I), while said coating is in place over the Yub 7L~dL~ surface as forrned in step (1), for a suff~cient time at a sufficient temper-ature to convert the liquid coating to a solid a&erent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), with-out c~nCing irreversible exr~n~ion of the gas filled, polymer walled microbal-loons present in the solid coating; and, optionally, one or more of the following steps:
25 ~I~I) causing the ~ccllmlll~tion of paint residues on the solid coating forrned in step (II) so as to forrn a soiled surface;
(l:V) irnmersing the soiled surface formed in step (III) in a volurne of water at a tem-perature at least high enough to cause irreversible expansion of the gas filled, pol-ymer walled rnicroballoons in the coating formed in step (II); and ~o ~ ,k i .. ~; .. g from the top surface of the volume of water in which the soiled surface was irnrnersed in step (IV) any floating solid particles forrned by ~ int~ogration in step (IV) of the coating formed in step (II), as a consequence of the irreversible W O 97/27241 PCT~US97/00007 e~p~n~ion of the gas filled, polymer walled microballoon constituents thereof.
Other embo-liment~ of the invention include coated substrates prepared by a process according to the invention as described above, the use of such coated substrates as grates in paint spray booths, and the like.
~etailed Description of the ~nvention~ Including Preferred Embodiments One of the important functions of component (A) as i~l~ntified above is to provide ~let~kifying activity for paint residues. Component (A) is ~l~r~lably selected from poly-mers of amide(s) of unsaturated carboxylic acids, more preferably of acrylic or metha-crylic acid, still more preferably of polyacrylamide only. The concentration of compon-ent (A) in a wor~ing composition according to the invention preferably is at least, with increasing preference in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, 4.5, 4.8, 5.2, 5.5, 5.8, or 6.0 % and indepen~lently preferably is not more than 30, 25, 20, lS, 10, 9.0, 8.5, 8.0, 7.5, 7.3, 7.1, 6.9, 6.7, 6.5, 6.3, or 6.2 %.
Component (B) may be selected from a wide variety of water insoluble polymers, preferably, primarily for reasons of economy, those commercially available in the form of dispersions or }atexes. An especially ~ler~llGd polymer type is copolymers of (i) vinyl esters of carboxylic acids with not more than four carbon atoms per acid molecule, most plGfGldbly vinyl acetate and (ii) at least one of the group cor~ ting of acrylic and metha-crylic acids and esters of acrylic and methacrylic acids, with esters being plGfclled and esters formed with alcohols cont~inin?~ not more than four carbon atoms still more pre-ferred. Independently of its chemical composition, the concentration of component (B) in a working composition according to the invention preferably is at least, with increas-ing p~ ,nce in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, 4.5, 4.9, 5.3, 5.7, 6.1, 6.3, 6.5, or 6.6 % and in~l~pçn~l~ntly preferably is not more than 30, 25, 20, lS, 10, 9.0, 8.5, 8.0, 7.5, 7.3,7.1,6.9,or6.8%.
For both components (A) and (B), smaller con~ entr~ti~ ns than those noted as pre-ferred generally result in a need for multiple coating steps and/or high concelll-dlions of viscosity increasing agents, which are relatively expensive compa-red with most other colll~ollents of a composition according to the invention, in order to achieve a desirable final film thickness after drying, while higher concentrations than those noted above as cr~lled are likely to result in a coating thirl~n~cs in a single pass that is higher than nec-essary to accomplish the purpose of the invention and Ih~ ro~ are uneconomical. Ex-CA 022429l2 l998-07-lO
W O 97/2724l PCT~US97/00007 cessively thick coatings also might unduly reduce the space available between the ele-ments of a grate to be coated, thereby frustrating its int~onde~ permeability to liquids.
Furthermore, high concentations of component (A) substantially increase the viscosity of an aqueous mixture cont~ining them, thereby aggravating a tendency to excessively 5 thick co~tin~
In order to achive highly desirable ~lOy~ Lies in the films formed, it is preferred that the ratio, in a composition according to the invention, of component (B) to compon-ent (A), which are the two principal binder const~ t?nt~ of the composition, should be at least, with increasing ~cr~,cllce in the order given, 0.30:1.0, 0.40:1.0, 0.50:1.0, 0.60:1.0, 10 0.70:1.0, 0.80:1.0, 0.90:1.0, 0.95:1.0, 1.00:1.0, 1.05:1.0, or 1.09:1.0 and independently preferably should be no more than, with increasing ylcr.,.~nce in the order given, 4.0:1.0, 3.5:1.0, 3.0:1.0, 2.5:1.0, 2.0:1.0, 1.7:1.0, 1.5:1.0, 1.3:1.0, 1.2:1.0, or 1.15:1Ø If the ratio of component (B) to component (A) is substantially higher than these yrercllcd values, the coatings formed are not likely to dislodge themselves readily from the underlying :jubsLIdte even after having been heated. Also, even if adequate dislo~lg~-n~ent does occur, still tacky particles of paint may be redi~y~l ~cd in the water often used to heat the coating according to the invention in order to dislodge it, and these tacky paint particles may re-deposit on unprotected surfaces before the s-~rf~çc can be recoated with a y.otcclive bar-rier. On the other hand, if the ratio of component (B) to component (A) is substantially lower than the yncrcllcd values, the barrier coating formed may dissolve too readily in low temperature water, with which they are usually in contact when in use, thereby re-quiring uneconomically frequent replacement of the barrier coating.
For culll~oncllL (C), suitable m~t~-ri~l~ are cdmmercially available from Expancel Inc., a subsidiary of Akzo Nobel, in Duluth, Georgia, USA under the narne EXPAN-CELTM ~ ed microballoons. Bothwet ~ d ("WU") and dry unexp~n-lecl ("DU") grades are available and appear to be equally useful in a composition according to the invention. Preferably, the average diameter, before expansion by he~ting of the microballoons used is not more than, with increasing ~l~r~,rcllce in the order given, 100, 70, 50, 40, 30, 25, or 20 llm and indepen~lently preferably is at least, with increasing 30 ~lcrcl~llce in the order given, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 ~m. Smaller micro-balloons than these ~c~l-~,d Ill;ll.lllllln sizes may not ~,cn~ ale suffrcient force upon ex-pansion to rupture the coating as desired, while larger microballoons than the preferred CA 022429l2 l998-07-lO
WO 97/27241 PCT/USg7/00007 m~imllm sizes are more difficult to disperse uniformly into coatings of the most desir-able 1hickn~c~ Independent}y, the amount of component (C) in a working composition according to the invention preferably is at least, with increasing preference in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, or 4.5 % and independently preferably is not more than, with increasing preference in the order given, 20, 15, 10, 8.0, 7.0, 6.5, 6.0, S.S, or S. l %.
A working liquid substrate coating composition according to this invention pref-erably is highly thixotropic, i.e., it preferably has a relatively high viscosity when begin-ning to be disturbed from a motionless state, but becomes relatively low in viscosity when subjected to stronger forces, so that it may readily be applied by convenient meth-ods such as spraying, dipping, brushing, and the like to a substrate to be protected, toform a coating that will remain in place against the influence of natural gravity without becoming thinned to an undesirable degree. The thixotropy may conveniently be mea-sured by means of a well known type of instrument, a Brookfield viscometer, using spindle # 4. The viscosity at 25 ~C of a liq~ud working coating compostion according to the invention measured in this way, when measured at I revolution per minute (he.eill~L-er abbreviated as "rpm") ~Icrc-dbly is at least, with increasing ~I~;r~.~.lce in the order given, 3000, S000, 7000, 9000, 10,000, 11,000, 12,000, 12,500, 13,000, or 13,500 centi-poises (hereinafter abbreviated as "cps"); independently preferably is, when measured at 5 rpm, at least, with ill~lcasillg prer~ lce in the order given, 2000, 2250, 2500, 2750, 3000, 3250, 3500, 3750, 4000, 4200, 4400,4600,4800, or 4900,CpS; and also independ-ently preferably is, when n.ea~ d at 20 rpm, not more than, with increasing ~refelence in the order given, 6000, 5000, 4000, 3750, 3500, 3250, 3000, 2750, 2500, or 2250 cps.
Achieving the most ~l~;r~ d viscosities as described above normally requires theuse of optional collll,onent (D) as recited above, because collll?ollcillL:i (A) through (C) do 2~; not normally ~3ollL~leously form compositions with the most ~l.,r~ ,d thixotropic prop-erties. A wide variety of natural and synthetic m~tPri~i~, such as natural gums and other polye~c~h~ es and various synthetic polymers, are known in the art for achieving thix-otropy and may be used in a composition according to the invention. The most ~l~,r~Ll~d material for component (D) when used is ~nth~n gum, preferably a type of this gum 30 which has been modified from its natural state to result in smoother flow ~LOpe- Lies at low shear rates. For any viscosity modifying component, the amount preferably should be sçlecte~ to achieve yl~r~,dble values of viscosities at various m~cllring speeds as al-CA 02242912 1998-07-lO
W O97/27241 PCT~US97/00007 ready specified above. For the ~refc,-~d modified xanthan gum as noted above, along with other ~l~r.,l.ed types and arnounts of components (A) through (C), the concentration of the modified x~nth~n gum in a liquid coating composition according to the invention preferably is at least, with increasing preference in the order given, 0.20, 0.30, 0.40, 0.50, 0.55, or 0.57 % and independently preferably is not more than, with increasing prefer-ence in the order given, 1.5, 1.0, 0.90, 0.80, 0.70, 0.65, 0.60, or 0.58 %.
The presence of optional component (E) in a composition according to the inven-tion is normally ~-~Ç~,.-ed, because such presence in a suitable amount has been found to f~ilit~te a desirable fracture and dislo~ment of the coating after expansion of com-ponent (C). When the filler has a specific gravaity of 2.7, the amount of filler in a liquidworking coating composition according to the invention preferably is at least, with in-creasing plefcr,llce in the order given, 2, 5, 8, 10, 11.0, 12.0, 13.0, 14.0, 14.5, 15.0, or 15.5 % of the total amount of components (A) and (B) and independently preferably is not more than, with increasing preference in the order given, 50, 45, 40, 35, 30, 25, 22, 20, 18, 16.8, 16.2, or 15.7 % ofthe total amount of components (A) and (B). If the specific ~ravity of the filler is dirr~ l, the plercl.~,d values should be adjusted to give the same volume of filler as the plefele..ces stated above for fillers with a specific gravity of 2.7.
Independently of the other ~lefe~.,l-ces, the m~imlltn particle size of the filler when used preferably is not more than, with increasing p.~fclellce in the order given, 100, 75, 50, 40, 30, 25, 22, 20, 18, or 16 ~m and independently the particle size preferab-ly is at least, with increasing l~lcrere-.ce in the order given, 2, 3, 4, 5, 6, 7, 8, 9, or 10 llm for at least 10 %, or more preferably, with ill~ a~hlg ~l~;rcl~llce in the order given, for at least 20, 30, 40, 50, 60, 70, 80, or 90 % of the total amount of filler.
The chemical nature of the filler is not believed to be significant to the success of the invention, provided that there is little or no chemical reaction between the filler and other components and that the filler is not soluble to an extent of as much as 1 % of its total in water. Any of the conventional insoluble mineral fillers such as talcs, clays, carbonates, and the like is suitable, with talc preferred.
The presence of optional colll~ollent ~F) is also normally ~ ,r~ d, because it has been found difficult uniformly to disperse microballoon component (C) and sometimes also filler collll)olltllL (E) when used into a working liquid coating composition according W O97/27241 PCTrUS97100007 to the invention when no surfactant dispersing agent is present. Any of a wide variety of dispersing agents generally known in the art is suitable if it leads to effective disper-sion and stability of the r~clllting final working coating composition. A preferred type of dispersing agent is one having general chemical formula (I): y RIO(CH2CH2O)y(CH2CHCH3O)zH (I) where Rl is a moiety selected from the group concict;ng of s~tllr~t.o~l-and-unsaturated straight-and-branched-chain-aliphatic-monovalent-hydrocarbon-moiety-substituent -bearing phenyl moieties in which the aromatic ring is directly bonded to the oxygen atom appearing imme~i~tely after the R' symbol in formula (II); y is a positive integer, and z is zero, one, or two. Preferably, independently for each yler~ ce stated, z is I or 0, more preferably zero; the aliphatic monovalent hydrocarbon moiety substituent in R' has at least, with increasing preference in the order given, 5, 6, 7, 8, or 9 carbon atoms and indepPn~l~ntly ylef~.~ly has not more than, with increasing yn'erel~;llce in the order giv-en, 12, 11, 10, or 9 carbon atoms; the aliphatic monovalent hydrocarbon moiety substitu-ent in Rl is straight chain rather than branched; and the average value of y is at least, with increasing l,lcr~,,ellce in the order given, 3, 4, 5, 6, 7, or 8 and indepenrl~ntly preferably is not more than, with increasing ~.cr~ llce in the order given, 16,15,14,13,12,1 1,10, or9.
~he pH value of a liquid working coating composition according to the invention,at least when the substrate metal to be coated is mild steel, preferably is at leact, with in-creasing yl~re~cllce in the order given, 5.0, 6.0, 6.5, 7.0, 7.5, 8.0, 8.3, or 8.6 and inde-pendently preferably is not more than, with increasing ~l~r~ ce in the order given, 12, 11, 10, or 9.5. Lower pH values than tnose noted as preferable mi~ s may result in excessive corrosion of the s~lbsh~tt-, or even failure to form a coating at all, while higher 25 pH values than those noted as preferred m~xiLc may adversely affect the properties of the other constituents of a working coating composition according to the invention.
Tn~cmllcl~ as components (A) through (F) alone would often result in pH values below those ylcr~ ,d, an ~Ik~line pH adjusting agent is generally preferably present as optional component (G) in a liquid coating composition according to the invention. Because they have an inherent corrosion inhibiting effect in addition to their pH raising effect, water soluble organic amines are yl~rel.ed for comy~ ent (G) when an increase in pH is need-ed, and, prim~rily in order to minimi7e odor m~ic~nces, relatively non-volatile amines CA 02242912 1998-07-lO
such as mono-, di-, and, particuiarly, tri-ethanol amines are especially preferred. Should a decrease in pH be needed, many suitable acid m~t.-ri~1~ to serve as pH adjusting agents are known to those skilled in the art.
Optional colorant component (H) is not believed to have any important technical function in the operation of the invention, but may be desirable in many applications for decorative or visibility-increasing purposes. Numerous conventional dyes and/or pigment~ may be used for component (H) as known to those skilled in the art.
Optional biocidal component (J~ nnrm~lTy is ~l~r~.dbly present in a liquid compo-sition according to the invention in an amount effective to repress the biodegradation of 10 some of the components of the composition, especially component (A~, that other~vise readily occurs from the action of micro-org~ni~m~ commonly found in the natural atrnos-phere.
The liquid coating initially forrned may be adquately dried by mere exposure to normal ambient air at a humidity less than l 00 %. However, because several hours may be required for drying by this method, it is normally plere~ d to utilize hot air for drying.
More particularly, air used to dry the liquid coating initially formed preferably has a tclll~cldLulc tnat is at ieast, Witil increasing ~l~,relcnce in the order given, 38, 43, 48, 53, 57, or 60 ~C and independently preferably is not more than, with increasing pler.,lcllce in the order given, 75, 72, 69, or 67 ~C; higher lclll~ dlulcs than these will subs1~nti~11y increase the risk of unwanted premature irreversible expansion of the microballoons in the coating, and achieve only slightly greater drying speeds, as shown in some of the working exarnples below.
In order to achieve the most desired characteristics, a dried but unexpanded pro-tective coating according to the invention preferably has a thicknl?cc that is at least, with hl,l~ illg~lc;r~;lellceintheordergiven, l2, l5, l8,2l,24,27,or30,umandindepend-ently ~lGr~ ly is, primarily for reasons of economy, not more than l 00, 75, 65, 55, 45, or 35 ~lm. Also, of course, when used on grates, co~tingC according to the invention nor-mally should not be so thick as to make the grates illl~ lllleable to fluids.
When a dried coating according to the invention has accurnulated a sufficient amount of paint on its surface, the coating is preferably caused to break apart and dislodge itself from the substrate by immer.cion in hot water, although spraying of hot water and/or steam, hot air, or other methods of heating can also be used. Hot water is CA 02242912 1998-07-lO
~c~lled when pr~rtiç~1, because heat transfer from it to the coating is relatively efficient and dislodgement and sc~aldLion are facilitated by the fact that the coating, at least if it is one of the most ~lcfellcd embodiments, will float on water after the irreversible exr~n~ion of the microballoons occurs, but not before. In particular, hot water with a le~ "dLulc that preferably is at least, with increasing ~ nce in the order given7 80, 827 847 86, 88, 90, or 92 ~C is used. Although the use of still higher temperature water has no adverse effect on the break up and dislo~lgement of the coating, it does not provide much if any practically higher break up and dislodgement speed and does require a higher energy cost. Therefore, when hot water is used for this purpose, its temperature 10 indep~n~l~nt1y p,cf~-dbly is not more than, with increasing preference in the order given, 987 967 or 94 ~C. If steam, air7 or another purely gaseous heat transfer mediurn is used7 subst~nti~lly higher temperatures than these for the heat transfer mediurn are preferred to CO111~G11 ,a~e for the relatively slow heat transport capacity of a gas.
Highly ple~..~,d coatings according to the invention break apart within a few ~ IP.~ wheni~ ~~inhot waterata~l~r~ dt~ .dl~cand floattothetop ofthevessel in which they are immersed7 thereby making possible a facile separation by skim-ming off the broken particles formed. Any tacky paint that may sep~dLe during the breakup and dislo~lgemPnt process normally is r1~t~ ified by residual components (A) and (B) of the co~ting Component (A) has the major ~1et~ifying effect7 but colll~onell~
(B3 also aids in ~lpt~ ification by forming water-insoluble particles that stick to tacky paint surfaces and thereby reduce the effectively tacky area of any originally tacky sur-face. As a consequence of the combined action of these two components7 the ~kimmeA
particles of the coating do not stick readily to any other s ~ rç~ with which they may come into contact. Therefore7 after broken up particles of the coating have beens~im mP~l offthe surface of hot water in which a coated ~ub 7~d~t; according to the inven-tion was immerse~l to break up the co~ting, the "1, 71.~ may n~rm~1ly be removed from the hot water7 dried7 and then recoated with a coating composition according to the in-vention for continl-ed use7 and such coating and dislodgement cycles may be contin as many times as desired on the same substrate.
The invention may be further ~lc~;iated by consideration of the following ex-atnples7 and its benefits may be appreciated by coll~alison with other methods.
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W O 97/27241 PCT~US97/00007 Fxamples Materials Used CYANAMERTM N-lOOL polyacrylamide solution in water, reported by its supplier to contain 50 - 52 % of polyacrylamide, was obtained commercially from Cytek Industries.
FLEXBONDTM 325 latex dispersion of a copolymer of vinyl acetate and acrylate, reported by its supplier to contain 55.8 % solids of a polymer with a glass transition temperature of 15 ~C dispersed in water, was obtained commercially from Air Products and Chemicals.
EXPANCELTM 642 WU and 820 DU grades of gas filled microballoons were obtained commercially from Expancel Inc. as noted above. Grade 642 VVU is reported by its supplier to contain 65 % of microballoons with diameters ranging from 3 to 30 !lm, with the balance of the material being water in which the microballoons are dispersed;
grade 820 DU is reported by its supplier to be 100 % microballoons with ~ met~rsranging from 10 to 16 ,um. For both grades, the filling gas is reported to be iso-butane and the po~ymer walls to be made of acrylonitrile-vinylidene chloride copolymer.KELZANTM AR x~~ an gurn powder was commercially obtained from the Kelco division of Merck & Co., Inc. and is reported by its supplier to contain 86 - 92 % solids of ~c~nth~n gum (which is constituted of polymers of ,~-1 ,4-linked D-glucose units) that 20 has been modifed to give lower viscosity at low shear rates than unrnodified natural xan-than gurn. For exarnple, a solution of 0.3 % of each of potassium chloride and KEL-ZANTM A~ in water has a viscosity of about 800 cps at a shear rate of 0.1 reciprocal sec-onds (helGi~ usually abbreviated as "sec ~"), whereas an otherwise identical solution of natural ~nths~n gum has a viscosity of almost l O,OOO cps. At a shear rate of 10 sec~~, 25 the viscosities ofthese solutions are about 100 and 500 cps respectively. K8C241TM un-modified ~ nth~n gum was also obtained cornmercia~ly from Kelco.
NATROSOLTM 250H4R hydroxyethylcellulose was obtained commercially from Aqualon, a division of Hercules, Inc., in WilmingtQn, Delaware, U.S.A. and is reported by its supplier to have a molecular weight, est;m~ted from intrinsic viscosity measure-ments, of 1.1 x 1 o6; a solution of 1 % of it in water is reported by its supplier to have aviscosity of 2600 - 3300 cps at 25 ~C when measured with a Brookfield vi~com~ter using spindle #3 at 30 rpm.
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W O 97/27241 PCTrUS97/00007 MICROTALCTM MP 15-3 8 filler was commercially obtained from Marietta Min-erals, Dillon, Montana and is reported by its supplier to be a mined m:~gnesium silicate mineral with a n1a;~ particle size of 15 ,um and the chemical formula Mg3H2(SiO3)4.
IGEPALTM C0-630 s~ rt~nt was obtained commercially ~rom Rhône-Poulenc 5arld is reported by its supplier to be nonylphenol[poly(oxyethylene)]ethanol with an average molecular weight of 616.
BUTOXYNETM 497 corrosion inhibitor was obtained commercially from ISP
Technologies, Inc., Wayne, New Jersey, VSA and is reported by its supplier to be 1,4-bis(2-h)~dro~y~llloxy)-2-butyne~
0~OSTACORTM 2732 inhibitor was obtained commercially from Hoechst Celan-ese Corp. and is reported by its supplier to be "a~ylamido carboxylic acid".
l riethanol amine, 99 % pure. was used as a pH adjusting agent and corrosion in-hibitor.
DOWICIDETM A Flake antimicrobial was obtained commercially from Van 15Waters and Rogers, Kirkland, Wz~chingt n, USA and is reported by its supplier to contain 97 % of sodium orthopheynylphenate tekahydrate and 1 - 2 % of sodium hydroxide.
UNISPERSETM Blue pigment was obtained commercially from Ciba-Geigy as a paste.
CELOGENTM 780 was obtained commercialIy from Uniroyal Chemicals and is 20 reported by its supplier to be "activated" azodic~l~o. ~,.~id~ . This is a conventional blow-ing agent.
Working Coating Compositions Fx~mr1e working compositions according to the invention are set forth in Table 1 below. Blank cells in the table in~lic~te that none ofthe m~t~ri~l was added to the com-26position, or that the ~ elLy value that would ~ .ly appear in the cell was notmeasured. (Only the first three digits of the viscosity measurements are considered sig-nificant within the limits of reproducibility of the mea~ ; the final zeros are shown merely for the sake of . ,po~Lillg in the most conventional units.3 W O 97/27241 PCT~US97/00007 TABLE I
Material % of Material in Composition Number Deionized Water 72 74 74 74.2 69.2 70.270.0 DOWICIDETM A Flake 0.10 0.100.10 0.10 0.10 KELZANTM AR 0.6 0.6 0.7 0.65 0.65 0.650.80 CYANAMERTM N-lOOL 10.0 10.010.0 10.0 10.0 10.010.0 FLEXBONDTM 325 10.0 10.010.0 10.0 10.0 10.010.0 IGEPALTM C0-630 1.00 1.001.00 1.00 1.00 1.001.00 MICROTALCTM MP lS-38 CELOGENTM 780 2.00 2.00 EXPAI~CELTM 642 WU 6.00 6.00 5-00 6.00 EXPANCELTM 820 DU 4.00 4.00 4.00 HOSTACORTM 2732 2.00 BUTOXYNETM 497 2.00 99% Triethanolamine 2.00 2.00 2.00 UNISPERSETM Blue 0.10 0.100.10 0.01 0.10 0.100.10 Other Properties of the Magnitude of the Property in Composiffon Number:
CQmPOS;~;On~
Visco,ilylat20rpm,cps177017701720 1710 1920 18802680 Viscosity' at 5 rpm, cps 4000 3720 7040 Viscosity' at 1 rpm, cps 12,40010,200 22~400 pH S. l S.O 9.0 9.1 5.6 5.6 9.0 The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Sp;ndle # 4.
... Table I is conbnued on the next page ...
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W O 97/27241 PCT~US97/00007 Material % of Material in Composition Number Deionized Water 72.0 64.5 66.5 62.6 67.6 62.5 64.5 DOWlCIDETMAFlake 0.10 0.10 0.10 0.10 0.10 0.10 0.10 KELZANTM AR 0.80 0.80 0.80 0.75 0.75 NATROSOLTM 250H4R o.so o.so K8C241TI'' o 30 0 30 CYANAMERTM N-lOOL 10.0 12.0 12.0 12.0 12.0 12.0 12.0 ~ FLEXBONDTM325 10.0 12.0 12.0 12.0 12.0 12.0 12.0 IGEPALTM C0-630 1.00 0.50 0.50 0.50 0.50 0.50 0.50 MICROTALCTM MP 2.00 2.00 2.00 2.00 1~-38 EXPANCELTM642 WU 7.00 7.00 7.00 E~PANCELTM 820 DU 4.00 5.00 5.00 5.00 99% Triethan~lqmi-~2.00 3.00 3.00 3.00 3.00 3.00 UNISPERSETM Blue 0.10 0.10 0.10 0.10 0.10 0.10 0.10 - Other Properties of the Magnitudle of the rl o ,c. ly in Compos~tion Number:
Compo~iti,~.c 8 9 10 11 12 13 14 Viscosityl at 20 rpm, cps2400 2740 2800 3030 2530 4400 4370 Viscosity I at 5 rpm, cps6160 7480 7920 9240 6880 11,600 12,000 pH 9.0 9.0 9.0 8.8 9.1 9.1 9.1 Visco,il~' ~t 1 rpm, cps19,00023~80025,60030,80021,20029,000 30,600 The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Spindle # 4.
... Table I is continued on the next page ...
W O 97/27241 PCT~US97/000~7 Material % of Material in Composition Number 16 17 18 19 21) Deionized Water 64.666.6 62.7 64.7 62.6 64.7 DOWICIDETM A Flake 0.100.10 0.10 0.10 0.10 0.10 KELZANTM AR 0.650.65 0.60 0.60 0.65 0.65 CYANAMERTM N-lOOL 12.012.0 12.0 12.0 12.0 12.0 FLEXBONDTM 325 12.012.0 12.0 12.0 12.0 12.0 IGEPALTM C0-630 O.SOO.SO O.SO O.SO O SO O.SO
MICROTALCTM MP 2.00 2.00 2.00 2.00 EXPANCELTM 642 WU 7.00 7.00 7.00 EXPANCELTM 820 DU S.OO S.OO S.OO
99 % Triethanolamine3.003.003.00 3.00 3.00 3.00 UNISPERSETM Blue 0.100.10 0.10 0.10 0.10 0.10 Other Properties of the IVls-gnitn(lf~ of the Property in Composition Number:
Compositions Viscosity' at 20 rpm, cps 2000 1840 1790 1770 2010 1900 Visc~ily~ at S rpm, cps5360 4240 4520 4400 5600 4920 Viscosily' at 1 rpm, cps 9200 10,4009200 15,400 13 600 pH 9.2 9.2 9.2 9.1 9.1 9.1 ~The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Spindle # 4.
-W O g7/2724i PCT~US97/~0007 Use Examples Each working composition defined in Table I was coated over a sample of con-ventional grate plate material for spray paint booths to produce a coating with a wet thie~n.o~s of about 0.20 mil limeters. The coating was then dried at a temperature of 60 ~C for a time of 20 minutes to produce a dry coating according to the invention. Various kinds of paint were caused to accumlate on the thus coated samples, by exposing them r to a laboratory scale paint spray booth, until the coating of paint in its thickest parts was about 0.51 miliimeters thick. The coated samples were then immersed in water at a tem-perature of 93 ~C. Within 30 seconds, breakup and dislodgement of the coating could be obseîved, and this process was completed within 90 seconds. The particles formed by breakup of the protective coating according to the invention and the paint adhered to it were ~kimmed off the top of the water in which the breakup of the coating had oc-curred. The vessel was then emptied and the previously coated metal substrate samples removed. No adherent paint on either the previously coated metal substrate samples or the walls of the vessel in which breakup of the co~ting~ had occurred was observed.
Time and Tel"~ re Variations for ~ryin~ Wet Coatin~s Accordin~ to the Invention In this group of e~anll.les, numerous coated samples of conventional grate material were prepared with a wet coating thickness of about 0.20 millimeters ofComposition No. 20 as shown in Table 1 and subjected to drying conditions as shown in Table 2 below, with the results also shown in Table 2. At the same time as the coated substrates were being exposed to drying conditions as reported in Table 2, a small alllmin1lm pan with a thin layer of the coating composition was exposed to the same drying conditions. Any visually perceptible roughening of the layer of coating, bubbles in the layer, irregularities in thicl!n~, or the like was regarded as evidence of the 2~ be~....;.-g of irreversible expansion ofthe microballoons, which of course is not desired at this stage of a process according to the invention.
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W O 97/27241 PCT~US97/00007 Tem- Time of Exposure to Temper~ture7 Minutes:
pera-~ ture, ~C 10 20 30 40 50 60 70 21 VW VW W W W W ex.W ex.E.
E.
32 VW W W ~x. E.D exDr. CD CD CD
43 W ex. E. 90 % D CD CD CD CD CD
54 90 % W 90 % D CD CD CD CD CD
66 75 % W CD CD CD CD CD CD
77 80 % D CD* CD* CD* CD* CD* CD*
88 CD* CD* CD* CD** CD**CD*~CD*~
Abbreviations and Notes for Table 2 VW = very wet; W = wet; ex. E. = except at edges; D = dry; ex. Dr. = except for a few wet drops; CD = completely dry; pc;~ lldges are estim~tecl area percents; * indicates that there was visual evidence of at least the beginning of expansion of the microballoons in the pan sample of the coating composition, but not in the coating on the grate samples;
** indicates that there was visual evidence of at least the beginning of expansion of microballoons in both the pan sample and the coating on the grate substrates; at 21 ~C, which was the ambient t~ ,eldl lre in the laboratory at the time of the tests, the relative humidity was 65 %; at other temperatures, the relative humidity was whatever resulted from heating air at the ambient temperature and humidity to the temperatures shown, without any added water.
W O 97/27241 PCTrUS97/00007 THERMALLY RELEASABLE BARRIER COATING, COMPOSITION
THEREFOR, AND USE THEREOF
Field of the Invention This invention relates to an improved composition and method for providing a tht-rm~lly releasable barrier coating for surfaces not intPn~le~1 to be painted but on which paintl nevertheless accnm~ tçs in practice because of the proximity of the ~urf~es not 5 inten~ l to be painted to other snrf~cçs that are intenflecl to be p~intçd The invention is more particularly applicable for coating the floor grates in paint spray booths or cabin-ets, such as are extensively used in mz~nllfslrturing automobiles and many other objects ti~at are decorated by p~inting Discussion of Related Art Numerous barrier coatings have been used in the prior art. Most have been re-moved when n~cec~7~1y by solvents, use of high ~les~ andlor high temperature water, mPrh~nic~l means, or the like, all of which to greater or lesser degrees are labor intens-iveS requ~re substantial volumes of at least moderately expensive materials, or both.
More recently, therm~lly removable barrier coatings have become known in the art.
Throughout this description, unless the context requires to the contrary, as where a specific m~tçri~l is named, the term "paint" is to be understood as encomp~ing all simi}ar terms such as enamel, lacquer, shellac, varnish, and the like.
WO 97127241 PCT~US97/00007 Most of those so far known utilize a combination of carbonate and/or acid carbonate salts with an acidic material that is prevented from coming into contact with the carbonate even when mixed with it at normal ambient temperatures, but that is brought into contact by some merhRnical and/or chemical means when the temperature of the solid co.~ g both components is raised, most often by contact with hot water and/or steam. The re-sulting reaction between acid and carbonate generates carbon dioxide gas that causes the coating to rupture and in principle to fall off the coated surface, or at least to become re-movable by light mechanical action.
These thermally removable barner coatings have fiimini~hed the labor and/or ma-10 terial costs compared with those of previous methods of removing protective barriercoRtin~s but in practice have been found to have certain difficulties: Complete removal is sometimes not reliably achieved; the paint Rcc~-mlllRtl-d on the barrier coating surface often becomes ~letRrh~l during the removal process, so that it can redeposit on the surface int~n~1e~ to be protected from being coated with it; pieces of the coating after 15 release can all too readily become trapped in the structure having the surface to be protected from paint, particularly when this structure has relatively narrow spacings be-tween solid elements, as is true in the grates conventionally used in paint spray booths;
and the internal barrier materials that prevent contact between carbonate ions and acid materials at ambient tempeldlul.,s can become unstable or otherwise suffer faults that 2a cause p~emature removal and/or unreliable or incomplete removal when desired. nESCRlPTION OF THE INVENTION
Ob~ects of the Invention A major object of the invention is to provide a new type of th~nRlly releasable b~ier coating that will overcome or at least ameliorate some or all of the problems with 25 prior art th~rmRlly releasable barrier coRtin~ as described above. Other objects will be a~ l from the description below.
General lPrinciples of Description Except in the claims _nd the specific ~rRmples, or where otherwise expressly in-dicated, all m-m.ori~ RI ~ lRntifies in this description indicating amounts of material or con-ditions of reaction and/or use are to be understood as modified by the word "about" indescribing the broadest scope of the invention. Practice within the numerical limits stat-ed is ~nerRlly pl~,r~llcd, however. Also, unless expressly stated or nece~isalily implied CA 02242912 1998-07-lO
by the context to the contrary: percent, "parts of", and ratio values are by weight; the term "polymer" includes "oligomer", "copolymer", "terpolymer", and the like; the first definition or description of the m~ning of a word, phrase, acronym, abbreviation or the like applies to all subsequent uses of the same word, phrase, acronym, abbreviation or the like and applies, mutatis mutandis, to normal grammatical variations thereof; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the mem-bers of the group or class are equally suitable or preferred; specifications in chemical terms of materials in compositions refers to the m~ten~l~ at the time of addition to any 10 composition so specified, and does not necessarily exclude the possibility of reaction between such materials with other materials already present in the composition at the time of addition of the specified materials; specification of materials in ionic form im-plies the ~les~"ce of sufficient counterions to produce electrical neutrality for the compo-sition as a whole; and any counterions thus implicitly specified preferably are selected from among other constituents explicitly specified in ionic form, to the extent possible;
otherwise such counterions may be freely selected, except for avoiding counterions that act adversely to the objects of the invention.
Summary of the Invention It has been discovered that a combination of (A) a nitrogen co. ~ ; . .g water solu-ble polymer, (B) a water insoluble film forming polymer, and (C) gas filled, polymer walled microballoons provides a superior th~.rrn~lly releasable coating that, at least in its most ~ r~,l..,d embodiments, (i) can be conveniently and reliably coated from a water based solution and dispersion onto surfaces to be protected against p~inting, (ii) is reliab-ly stable at ambient telllp~ldtures, (iii) even after being coated with many times its own thirl~n~ of accl-m~ tec~ paint particles, rapidly ~ int~ tes, along with the ~ccl~mlllS-t-ed paint coating formed on it, upon contact with hot water, into particles small enough that they readily escape from standard paint booth grate :iLlu-;Lul~;;s,(iv) normally detacki-fies any initially tacky paint particles that might escape during ~ tintPgration of the com-bined ~h~rrn~lly releasable coating and paint residues ~ccl-m~ te~l thereon, and (v) dis-i~ Les into particles that fioat on water, so that they can be readily removed from thegrates by imme.r.~ing the latter in hot water. allowing a few minutes for the disintegration to take effect, and then skimming of the floating solids on the surface of the water.
. CA 02242912 1998-07-lO
W O97/27241 PCTrUS97/00007 A polymer is defined as "film forming" for the purposes of this description if, when a solution or suspension of the polymer in water is dried at a tem~,.dLIlre of at least 25~ C from a liquid film thickness not greater than 1 millimet~?r, a continuous and coher-ent film that is solid at 25~ C is produced.
One major embodiment of the invention is a suitable liquid coating composition for applying a th~?rm~lly releasable barrier coating, the liquid coating composition com-prising, preferably consisting essentially of, or more preferably consisting of, water and:
(~) a component of water soluble polymer m~ri~1 that (i) is solid at 25 ~C, (ii) con-tains at least, with illcle~illg ~rer~.~,.lce in the order given, 1, 2, 4, 7, 10, 13, 15, 17, or 18.0 percent of nitrogen atoms bonded into a chemical moiety selected from the group con-cict;ng of amido and c~ l y ammoniurn moieties, and (iii) is soluble in water to an extent of at least 5 % at 25 ~C and normal atmosphericpressure;
(B) a component of film forming polymer that is not soluble in water to an extent of as much as 4.5 % at 25 ~C and norrnal atmospheric pressure but is stably dis-persed in the coating composition; and;
~C~ a component of gas filled, polymer walled microballoons having the ~10~eL lies that (i) they are stably di~ersed in the coating composition and remain stably dis-persed and subst~nti~lly une~cr~n-lf?d when the coating composition is m~
at a temperature not greater than 65 ~C; and (ii) when exposed for at least five5 to at least one tel~ a~ ; in the range from 80 to 95 ~C, they undergo an h~ev~l~,ible expansion, without wall rupture, so as to produce an e~r~nLl~d form which has a density not greater than 0.5 times their density before having ç~rr~ntl~l, and, optionally, one or more of the following colll~onents:
a coll-~on~llL of viscosity modifying agent(s) that are not part of any of the previ-ously recited components;
~) a component of solid filler that is not part of any ol: the previously recited com-ponents;
~F~ a component of dispersing agent that is not part of any of the previously recited 31) components;
~G) a component of pH adJusting agent and/or corrosion inhibitor that is not part of any of the previously recited components;
CA 02242912 1998-07-lO
W O 97/27241 PCTrUS97/00007 ~H) a component of coloring agent that is not part of any of the previously recited components; and (J) a component of biocide that is not part of any of the previously recited compon-ents, said liquid coating composition having the properties that it can be formed into a liquid coating over a solid subskate surface and that the thus-formed liquid coating can be con-verted, by heating the liquid film in place on the substrate to a temperature not greater than 65 ~C under normal atmospheric pressure for a time not greater than one hour, into a coherent continuous solid coating that adheres to the ~,u~ ale .
Another embodirnent ofthe invention is a process comprising, preferably consist-ing e~senti~lly of, or more preferably consisting of, the steps of:
(I) forming on a substrate surface to be protected against accumulation of paint thereon a liquid coating of a liquid coating composition according to the inven-tion as described above, said liquid coating having a thickness corresponding toat least a thickness of 12 micrometres (h~ ,hla~l~;r usually abbreviated as ",~Lm"~
of cc-n~titu~nt~ of the liquid coating composition that remain present after the li-quid coating is heated to 65 ~C~ for at least one hour; and (II) drying the liquid coating forrned in step (I), while said coating is in place over the Yub 7L~dL~ surface as forrned in step (1), for a suff~cient time at a sufficient temper-ature to convert the liquid coating to a solid a&erent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), with-out c~nCing irreversible exr~n~ion of the gas filled, polymer walled microbal-loons present in the solid coating; and, optionally, one or more of the following steps:
25 ~I~I) causing the ~ccllmlll~tion of paint residues on the solid coating forrned in step (II) so as to forrn a soiled surface;
(l:V) irnmersing the soiled surface formed in step (III) in a volurne of water at a tem-perature at least high enough to cause irreversible expansion of the gas filled, pol-ymer walled rnicroballoons in the coating formed in step (II); and ~o ~ ,k i .. ~; .. g from the top surface of the volume of water in which the soiled surface was irnrnersed in step (IV) any floating solid particles forrned by ~ int~ogration in step (IV) of the coating formed in step (II), as a consequence of the irreversible W O 97/27241 PCT~US97/00007 e~p~n~ion of the gas filled, polymer walled microballoon constituents thereof.
Other embo-liment~ of the invention include coated substrates prepared by a process according to the invention as described above, the use of such coated substrates as grates in paint spray booths, and the like.
~etailed Description of the ~nvention~ Including Preferred Embodiments One of the important functions of component (A) as i~l~ntified above is to provide ~let~kifying activity for paint residues. Component (A) is ~l~r~lably selected from poly-mers of amide(s) of unsaturated carboxylic acids, more preferably of acrylic or metha-crylic acid, still more preferably of polyacrylamide only. The concentration of compon-ent (A) in a wor~ing composition according to the invention preferably is at least, with increasing preference in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, 4.5, 4.8, 5.2, 5.5, 5.8, or 6.0 % and indepen~lently preferably is not more than 30, 25, 20, lS, 10, 9.0, 8.5, 8.0, 7.5, 7.3, 7.1, 6.9, 6.7, 6.5, 6.3, or 6.2 %.
Component (B) may be selected from a wide variety of water insoluble polymers, preferably, primarily for reasons of economy, those commercially available in the form of dispersions or }atexes. An especially ~ler~llGd polymer type is copolymers of (i) vinyl esters of carboxylic acids with not more than four carbon atoms per acid molecule, most plGfGldbly vinyl acetate and (ii) at least one of the group cor~ ting of acrylic and metha-crylic acids and esters of acrylic and methacrylic acids, with esters being plGfclled and esters formed with alcohols cont~inin?~ not more than four carbon atoms still more pre-ferred. Independently of its chemical composition, the concentration of component (B) in a working composition according to the invention preferably is at least, with increas-ing p~ ,nce in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, 4.5, 4.9, 5.3, 5.7, 6.1, 6.3, 6.5, or 6.6 % and in~l~pçn~l~ntly preferably is not more than 30, 25, 20, lS, 10, 9.0, 8.5, 8.0, 7.5, 7.3,7.1,6.9,or6.8%.
For both components (A) and (B), smaller con~ entr~ti~ ns than those noted as pre-ferred generally result in a need for multiple coating steps and/or high concelll-dlions of viscosity increasing agents, which are relatively expensive compa-red with most other colll~ollents of a composition according to the invention, in order to achieve a desirable final film thickness after drying, while higher concentrations than those noted above as cr~lled are likely to result in a coating thirl~n~cs in a single pass that is higher than nec-essary to accomplish the purpose of the invention and Ih~ ro~ are uneconomical. Ex-CA 022429l2 l998-07-lO
W O 97/2724l PCT~US97/00007 cessively thick coatings also might unduly reduce the space available between the ele-ments of a grate to be coated, thereby frustrating its int~onde~ permeability to liquids.
Furthermore, high concentations of component (A) substantially increase the viscosity of an aqueous mixture cont~ining them, thereby aggravating a tendency to excessively 5 thick co~tin~
In order to achive highly desirable ~lOy~ Lies in the films formed, it is preferred that the ratio, in a composition according to the invention, of component (B) to compon-ent (A), which are the two principal binder const~ t?nt~ of the composition, should be at least, with increasing ~cr~,cllce in the order given, 0.30:1.0, 0.40:1.0, 0.50:1.0, 0.60:1.0, 10 0.70:1.0, 0.80:1.0, 0.90:1.0, 0.95:1.0, 1.00:1.0, 1.05:1.0, or 1.09:1.0 and independently preferably should be no more than, with increasing ylcr.,.~nce in the order given, 4.0:1.0, 3.5:1.0, 3.0:1.0, 2.5:1.0, 2.0:1.0, 1.7:1.0, 1.5:1.0, 1.3:1.0, 1.2:1.0, or 1.15:1Ø If the ratio of component (B) to component (A) is substantially higher than these yrercllcd values, the coatings formed are not likely to dislodge themselves readily from the underlying :jubsLIdte even after having been heated. Also, even if adequate dislo~lg~-n~ent does occur, still tacky particles of paint may be redi~y~l ~cd in the water often used to heat the coating according to the invention in order to dislodge it, and these tacky paint particles may re-deposit on unprotected surfaces before the s-~rf~çc can be recoated with a y.otcclive bar-rier. On the other hand, if the ratio of component (B) to component (A) is substantially lower than the yncrcllcd values, the barrier coating formed may dissolve too readily in low temperature water, with which they are usually in contact when in use, thereby re-quiring uneconomically frequent replacement of the barrier coating.
For culll~oncllL (C), suitable m~t~-ri~l~ are cdmmercially available from Expancel Inc., a subsidiary of Akzo Nobel, in Duluth, Georgia, USA under the narne EXPAN-CELTM ~ ed microballoons. Bothwet ~ d ("WU") and dry unexp~n-lecl ("DU") grades are available and appear to be equally useful in a composition according to the invention. Preferably, the average diameter, before expansion by he~ting of the microballoons used is not more than, with increasing ~l~r~,rcllce in the order given, 100, 70, 50, 40, 30, 25, or 20 llm and indepen~lently preferably is at least, with increasing 30 ~lcrcl~llce in the order given, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 ~m. Smaller micro-balloons than these ~c~l-~,d Ill;ll.lllllln sizes may not ~,cn~ ale suffrcient force upon ex-pansion to rupture the coating as desired, while larger microballoons than the preferred CA 022429l2 l998-07-lO
WO 97/27241 PCT/USg7/00007 m~imllm sizes are more difficult to disperse uniformly into coatings of the most desir-able 1hickn~c~ Independent}y, the amount of component (C) in a working composition according to the invention preferably is at least, with increasing preference in the order given, 1.0, 2.0, 3.0, 3.5, 4.0, or 4.5 % and independently preferably is not more than, with increasing preference in the order given, 20, 15, 10, 8.0, 7.0, 6.5, 6.0, S.S, or S. l %.
A working liquid substrate coating composition according to this invention pref-erably is highly thixotropic, i.e., it preferably has a relatively high viscosity when begin-ning to be disturbed from a motionless state, but becomes relatively low in viscosity when subjected to stronger forces, so that it may readily be applied by convenient meth-ods such as spraying, dipping, brushing, and the like to a substrate to be protected, toform a coating that will remain in place against the influence of natural gravity without becoming thinned to an undesirable degree. The thixotropy may conveniently be mea-sured by means of a well known type of instrument, a Brookfield viscometer, using spindle # 4. The viscosity at 25 ~C of a liq~ud working coating compostion according to the invention measured in this way, when measured at I revolution per minute (he.eill~L-er abbreviated as "rpm") ~Icrc-dbly is at least, with increasing ~I~;r~.~.lce in the order given, 3000, S000, 7000, 9000, 10,000, 11,000, 12,000, 12,500, 13,000, or 13,500 centi-poises (hereinafter abbreviated as "cps"); independently preferably is, when measured at 5 rpm, at least, with ill~lcasillg prer~ lce in the order given, 2000, 2250, 2500, 2750, 3000, 3250, 3500, 3750, 4000, 4200, 4400,4600,4800, or 4900,CpS; and also independ-ently preferably is, when n.ea~ d at 20 rpm, not more than, with increasing ~refelence in the order given, 6000, 5000, 4000, 3750, 3500, 3250, 3000, 2750, 2500, or 2250 cps.
Achieving the most ~l~;r~ d viscosities as described above normally requires theuse of optional collll,onent (D) as recited above, because collll?ollcillL:i (A) through (C) do 2~; not normally ~3ollL~leously form compositions with the most ~l.,r~ ,d thixotropic prop-erties. A wide variety of natural and synthetic m~tPri~i~, such as natural gums and other polye~c~h~ es and various synthetic polymers, are known in the art for achieving thix-otropy and may be used in a composition according to the invention. The most ~l~,r~Ll~d material for component (D) when used is ~nth~n gum, preferably a type of this gum 30 which has been modified from its natural state to result in smoother flow ~LOpe- Lies at low shear rates. For any viscosity modifying component, the amount preferably should be sçlecte~ to achieve yl~r~,dble values of viscosities at various m~cllring speeds as al-CA 02242912 1998-07-lO
W O97/27241 PCT~US97/00007 ready specified above. For the ~refc,-~d modified xanthan gum as noted above, along with other ~l~r.,l.ed types and arnounts of components (A) through (C), the concentration of the modified x~nth~n gum in a liquid coating composition according to the invention preferably is at least, with increasing preference in the order given, 0.20, 0.30, 0.40, 0.50, 0.55, or 0.57 % and independently preferably is not more than, with increasing prefer-ence in the order given, 1.5, 1.0, 0.90, 0.80, 0.70, 0.65, 0.60, or 0.58 %.
The presence of optional component (E) in a composition according to the inven-tion is normally ~-~Ç~,.-ed, because such presence in a suitable amount has been found to f~ilit~te a desirable fracture and dislo~ment of the coating after expansion of com-ponent (C). When the filler has a specific gravaity of 2.7, the amount of filler in a liquidworking coating composition according to the invention preferably is at least, with in-creasing plefcr,llce in the order given, 2, 5, 8, 10, 11.0, 12.0, 13.0, 14.0, 14.5, 15.0, or 15.5 % of the total amount of components (A) and (B) and independently preferably is not more than, with increasing preference in the order given, 50, 45, 40, 35, 30, 25, 22, 20, 18, 16.8, 16.2, or 15.7 % ofthe total amount of components (A) and (B). If the specific ~ravity of the filler is dirr~ l, the plercl.~,d values should be adjusted to give the same volume of filler as the plefele..ces stated above for fillers with a specific gravity of 2.7.
Independently of the other ~lefe~.,l-ces, the m~imlltn particle size of the filler when used preferably is not more than, with increasing p.~fclellce in the order given, 100, 75, 50, 40, 30, 25, 22, 20, 18, or 16 ~m and independently the particle size preferab-ly is at least, with increasing l~lcrere-.ce in the order given, 2, 3, 4, 5, 6, 7, 8, 9, or 10 llm for at least 10 %, or more preferably, with ill~ a~hlg ~l~;rcl~llce in the order given, for at least 20, 30, 40, 50, 60, 70, 80, or 90 % of the total amount of filler.
The chemical nature of the filler is not believed to be significant to the success of the invention, provided that there is little or no chemical reaction between the filler and other components and that the filler is not soluble to an extent of as much as 1 % of its total in water. Any of the conventional insoluble mineral fillers such as talcs, clays, carbonates, and the like is suitable, with talc preferred.
The presence of optional colll~ollent ~F) is also normally ~ ,r~ d, because it has been found difficult uniformly to disperse microballoon component (C) and sometimes also filler collll)olltllL (E) when used into a working liquid coating composition according W O97/27241 PCTrUS97100007 to the invention when no surfactant dispersing agent is present. Any of a wide variety of dispersing agents generally known in the art is suitable if it leads to effective disper-sion and stability of the r~clllting final working coating composition. A preferred type of dispersing agent is one having general chemical formula (I): y RIO(CH2CH2O)y(CH2CHCH3O)zH (I) where Rl is a moiety selected from the group concict;ng of s~tllr~t.o~l-and-unsaturated straight-and-branched-chain-aliphatic-monovalent-hydrocarbon-moiety-substituent -bearing phenyl moieties in which the aromatic ring is directly bonded to the oxygen atom appearing imme~i~tely after the R' symbol in formula (II); y is a positive integer, and z is zero, one, or two. Preferably, independently for each yler~ ce stated, z is I or 0, more preferably zero; the aliphatic monovalent hydrocarbon moiety substituent in R' has at least, with increasing preference in the order given, 5, 6, 7, 8, or 9 carbon atoms and indepPn~l~ntly ylef~.~ly has not more than, with increasing yn'erel~;llce in the order giv-en, 12, 11, 10, or 9 carbon atoms; the aliphatic monovalent hydrocarbon moiety substitu-ent in Rl is straight chain rather than branched; and the average value of y is at least, with increasing l,lcr~,,ellce in the order given, 3, 4, 5, 6, 7, or 8 and indepenrl~ntly preferably is not more than, with increasing ~.cr~ llce in the order given, 16,15,14,13,12,1 1,10, or9.
~he pH value of a liquid working coating composition according to the invention,at least when the substrate metal to be coated is mild steel, preferably is at leact, with in-creasing yl~re~cllce in the order given, 5.0, 6.0, 6.5, 7.0, 7.5, 8.0, 8.3, or 8.6 and inde-pendently preferably is not more than, with increasing ~l~r~ ce in the order given, 12, 11, 10, or 9.5. Lower pH values than tnose noted as preferable mi~ s may result in excessive corrosion of the s~lbsh~tt-, or even failure to form a coating at all, while higher 25 pH values than those noted as preferred m~xiLc may adversely affect the properties of the other constituents of a working coating composition according to the invention.
Tn~cmllcl~ as components (A) through (F) alone would often result in pH values below those ylcr~ ,d, an ~Ik~line pH adjusting agent is generally preferably present as optional component (G) in a liquid coating composition according to the invention. Because they have an inherent corrosion inhibiting effect in addition to their pH raising effect, water soluble organic amines are yl~rel.ed for comy~ ent (G) when an increase in pH is need-ed, and, prim~rily in order to minimi7e odor m~ic~nces, relatively non-volatile amines CA 02242912 1998-07-lO
such as mono-, di-, and, particuiarly, tri-ethanol amines are especially preferred. Should a decrease in pH be needed, many suitable acid m~t.-ri~1~ to serve as pH adjusting agents are known to those skilled in the art.
Optional colorant component (H) is not believed to have any important technical function in the operation of the invention, but may be desirable in many applications for decorative or visibility-increasing purposes. Numerous conventional dyes and/or pigment~ may be used for component (H) as known to those skilled in the art.
Optional biocidal component (J~ nnrm~lTy is ~l~r~.dbly present in a liquid compo-sition according to the invention in an amount effective to repress the biodegradation of 10 some of the components of the composition, especially component (A~, that other~vise readily occurs from the action of micro-org~ni~m~ commonly found in the natural atrnos-phere.
The liquid coating initially forrned may be adquately dried by mere exposure to normal ambient air at a humidity less than l 00 %. However, because several hours may be required for drying by this method, it is normally plere~ d to utilize hot air for drying.
More particularly, air used to dry the liquid coating initially formed preferably has a tclll~cldLulc tnat is at ieast, Witil increasing ~l~,relcnce in the order given, 38, 43, 48, 53, 57, or 60 ~C and independently preferably is not more than, with increasing pler.,lcllce in the order given, 75, 72, 69, or 67 ~C; higher lclll~ dlulcs than these will subs1~nti~11y increase the risk of unwanted premature irreversible expansion of the microballoons in the coating, and achieve only slightly greater drying speeds, as shown in some of the working exarnples below.
In order to achieve the most desired characteristics, a dried but unexpanded pro-tective coating according to the invention preferably has a thicknl?cc that is at least, with hl,l~ illg~lc;r~;lellceintheordergiven, l2, l5, l8,2l,24,27,or30,umandindepend-ently ~lGr~ ly is, primarily for reasons of economy, not more than l 00, 75, 65, 55, 45, or 35 ~lm. Also, of course, when used on grates, co~tingC according to the invention nor-mally should not be so thick as to make the grates illl~ lllleable to fluids.
When a dried coating according to the invention has accurnulated a sufficient amount of paint on its surface, the coating is preferably caused to break apart and dislodge itself from the substrate by immer.cion in hot water, although spraying of hot water and/or steam, hot air, or other methods of heating can also be used. Hot water is CA 02242912 1998-07-lO
~c~lled when pr~rtiç~1, because heat transfer from it to the coating is relatively efficient and dislodgement and sc~aldLion are facilitated by the fact that the coating, at least if it is one of the most ~lcfellcd embodiments, will float on water after the irreversible exr~n~ion of the microballoons occurs, but not before. In particular, hot water with a le~ "dLulc that preferably is at least, with increasing ~ nce in the order given7 80, 827 847 86, 88, 90, or 92 ~C is used. Although the use of still higher temperature water has no adverse effect on the break up and dislo~lgement of the coating, it does not provide much if any practically higher break up and dislodgement speed and does require a higher energy cost. Therefore, when hot water is used for this purpose, its temperature 10 indep~n~l~nt1y p,cf~-dbly is not more than, with increasing preference in the order given, 987 967 or 94 ~C. If steam, air7 or another purely gaseous heat transfer mediurn is used7 subst~nti~lly higher temperatures than these for the heat transfer mediurn are preferred to CO111~G11 ,a~e for the relatively slow heat transport capacity of a gas.
Highly ple~..~,d coatings according to the invention break apart within a few ~ IP.~ wheni~ ~~inhot waterata~l~r~ dt~ .dl~cand floattothetop ofthevessel in which they are immersed7 thereby making possible a facile separation by skim-ming off the broken particles formed. Any tacky paint that may sep~dLe during the breakup and dislo~lgemPnt process normally is r1~t~ ified by residual components (A) and (B) of the co~ting Component (A) has the major ~1et~ifying effect7 but colll~onell~
(B3 also aids in ~lpt~ ification by forming water-insoluble particles that stick to tacky paint surfaces and thereby reduce the effectively tacky area of any originally tacky sur-face. As a consequence of the combined action of these two components7 the ~kimmeA
particles of the coating do not stick readily to any other s ~ rç~ with which they may come into contact. Therefore7 after broken up particles of the coating have beens~im mP~l offthe surface of hot water in which a coated ~ub 7~d~t; according to the inven-tion was immerse~l to break up the co~ting, the "1, 71.~ may n~rm~1ly be removed from the hot water7 dried7 and then recoated with a coating composition according to the in-vention for continl-ed use7 and such coating and dislodgement cycles may be contin as many times as desired on the same substrate.
The invention may be further ~lc~;iated by consideration of the following ex-atnples7 and its benefits may be appreciated by coll~alison with other methods.
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W O 97/27241 PCT~US97/00007 Fxamples Materials Used CYANAMERTM N-lOOL polyacrylamide solution in water, reported by its supplier to contain 50 - 52 % of polyacrylamide, was obtained commercially from Cytek Industries.
FLEXBONDTM 325 latex dispersion of a copolymer of vinyl acetate and acrylate, reported by its supplier to contain 55.8 % solids of a polymer with a glass transition temperature of 15 ~C dispersed in water, was obtained commercially from Air Products and Chemicals.
EXPANCELTM 642 WU and 820 DU grades of gas filled microballoons were obtained commercially from Expancel Inc. as noted above. Grade 642 VVU is reported by its supplier to contain 65 % of microballoons with diameters ranging from 3 to 30 !lm, with the balance of the material being water in which the microballoons are dispersed;
grade 820 DU is reported by its supplier to be 100 % microballoons with ~ met~rsranging from 10 to 16 ,um. For both grades, the filling gas is reported to be iso-butane and the po~ymer walls to be made of acrylonitrile-vinylidene chloride copolymer.KELZANTM AR x~~ an gurn powder was commercially obtained from the Kelco division of Merck & Co., Inc. and is reported by its supplier to contain 86 - 92 % solids of ~c~nth~n gum (which is constituted of polymers of ,~-1 ,4-linked D-glucose units) that 20 has been modifed to give lower viscosity at low shear rates than unrnodified natural xan-than gurn. For exarnple, a solution of 0.3 % of each of potassium chloride and KEL-ZANTM A~ in water has a viscosity of about 800 cps at a shear rate of 0.1 reciprocal sec-onds (helGi~ usually abbreviated as "sec ~"), whereas an otherwise identical solution of natural ~nths~n gum has a viscosity of almost l O,OOO cps. At a shear rate of 10 sec~~, 25 the viscosities ofthese solutions are about 100 and 500 cps respectively. K8C241TM un-modified ~ nth~n gum was also obtained cornmercia~ly from Kelco.
NATROSOLTM 250H4R hydroxyethylcellulose was obtained commercially from Aqualon, a division of Hercules, Inc., in WilmingtQn, Delaware, U.S.A. and is reported by its supplier to have a molecular weight, est;m~ted from intrinsic viscosity measure-ments, of 1.1 x 1 o6; a solution of 1 % of it in water is reported by its supplier to have aviscosity of 2600 - 3300 cps at 25 ~C when measured with a Brookfield vi~com~ter using spindle #3 at 30 rpm.
CA 02242912 1998-07-lO
W O 97/27241 PCTrUS97/00007 MICROTALCTM MP 15-3 8 filler was commercially obtained from Marietta Min-erals, Dillon, Montana and is reported by its supplier to be a mined m:~gnesium silicate mineral with a n1a;~ particle size of 15 ,um and the chemical formula Mg3H2(SiO3)4.
IGEPALTM C0-630 s~ rt~nt was obtained commercially ~rom Rhône-Poulenc 5arld is reported by its supplier to be nonylphenol[poly(oxyethylene)]ethanol with an average molecular weight of 616.
BUTOXYNETM 497 corrosion inhibitor was obtained commercially from ISP
Technologies, Inc., Wayne, New Jersey, VSA and is reported by its supplier to be 1,4-bis(2-h)~dro~y~llloxy)-2-butyne~
0~OSTACORTM 2732 inhibitor was obtained commercially from Hoechst Celan-ese Corp. and is reported by its supplier to be "a~ylamido carboxylic acid".
l riethanol amine, 99 % pure. was used as a pH adjusting agent and corrosion in-hibitor.
DOWICIDETM A Flake antimicrobial was obtained commercially from Van 15Waters and Rogers, Kirkland, Wz~chingt n, USA and is reported by its supplier to contain 97 % of sodium orthopheynylphenate tekahydrate and 1 - 2 % of sodium hydroxide.
UNISPERSETM Blue pigment was obtained commercially from Ciba-Geigy as a paste.
CELOGENTM 780 was obtained commercialIy from Uniroyal Chemicals and is 20 reported by its supplier to be "activated" azodic~l~o. ~,.~id~ . This is a conventional blow-ing agent.
Working Coating Compositions Fx~mr1e working compositions according to the invention are set forth in Table 1 below. Blank cells in the table in~lic~te that none ofthe m~t~ri~l was added to the com-26position, or that the ~ elLy value that would ~ .ly appear in the cell was notmeasured. (Only the first three digits of the viscosity measurements are considered sig-nificant within the limits of reproducibility of the mea~ ; the final zeros are shown merely for the sake of . ,po~Lillg in the most conventional units.3 W O 97/27241 PCT~US97/00007 TABLE I
Material % of Material in Composition Number Deionized Water 72 74 74 74.2 69.2 70.270.0 DOWICIDETM A Flake 0.10 0.100.10 0.10 0.10 KELZANTM AR 0.6 0.6 0.7 0.65 0.65 0.650.80 CYANAMERTM N-lOOL 10.0 10.010.0 10.0 10.0 10.010.0 FLEXBONDTM 325 10.0 10.010.0 10.0 10.0 10.010.0 IGEPALTM C0-630 1.00 1.001.00 1.00 1.00 1.001.00 MICROTALCTM MP lS-38 CELOGENTM 780 2.00 2.00 EXPAI~CELTM 642 WU 6.00 6.00 5-00 6.00 EXPANCELTM 820 DU 4.00 4.00 4.00 HOSTACORTM 2732 2.00 BUTOXYNETM 497 2.00 99% Triethanolamine 2.00 2.00 2.00 UNISPERSETM Blue 0.10 0.100.10 0.01 0.10 0.100.10 Other Properties of the Magnitude of the Property in Composiffon Number:
CQmPOS;~;On~
Visco,ilylat20rpm,cps177017701720 1710 1920 18802680 Viscosity' at 5 rpm, cps 4000 3720 7040 Viscosity' at 1 rpm, cps 12,40010,200 22~400 pH S. l S.O 9.0 9.1 5.6 5.6 9.0 The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Sp;ndle # 4.
... Table I is conbnued on the next page ...
CA 02242912 1998-07-lO
W O 97/27241 PCT~US97/00007 Material % of Material in Composition Number Deionized Water 72.0 64.5 66.5 62.6 67.6 62.5 64.5 DOWlCIDETMAFlake 0.10 0.10 0.10 0.10 0.10 0.10 0.10 KELZANTM AR 0.80 0.80 0.80 0.75 0.75 NATROSOLTM 250H4R o.so o.so K8C241TI'' o 30 0 30 CYANAMERTM N-lOOL 10.0 12.0 12.0 12.0 12.0 12.0 12.0 ~ FLEXBONDTM325 10.0 12.0 12.0 12.0 12.0 12.0 12.0 IGEPALTM C0-630 1.00 0.50 0.50 0.50 0.50 0.50 0.50 MICROTALCTM MP 2.00 2.00 2.00 2.00 1~-38 EXPANCELTM642 WU 7.00 7.00 7.00 E~PANCELTM 820 DU 4.00 5.00 5.00 5.00 99% Triethan~lqmi-~2.00 3.00 3.00 3.00 3.00 3.00 UNISPERSETM Blue 0.10 0.10 0.10 0.10 0.10 0.10 0.10 - Other Properties of the Magnitudle of the rl o ,c. ly in Compos~tion Number:
Compo~iti,~.c 8 9 10 11 12 13 14 Viscosityl at 20 rpm, cps2400 2740 2800 3030 2530 4400 4370 Viscosity I at 5 rpm, cps6160 7480 7920 9240 6880 11,600 12,000 pH 9.0 9.0 9.0 8.8 9.1 9.1 9.1 Visco,il~' ~t 1 rpm, cps19,00023~80025,60030,80021,20029,000 30,600 The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Spindle # 4.
... Table I is continued on the next page ...
W O 97/27241 PCT~US97/000~7 Material % of Material in Composition Number 16 17 18 19 21) Deionized Water 64.666.6 62.7 64.7 62.6 64.7 DOWICIDETM A Flake 0.100.10 0.10 0.10 0.10 0.10 KELZANTM AR 0.650.65 0.60 0.60 0.65 0.65 CYANAMERTM N-lOOL 12.012.0 12.0 12.0 12.0 12.0 FLEXBONDTM 325 12.012.0 12.0 12.0 12.0 12.0 IGEPALTM C0-630 O.SOO.SO O.SO O.SO O SO O.SO
MICROTALCTM MP 2.00 2.00 2.00 2.00 EXPANCELTM 642 WU 7.00 7.00 7.00 EXPANCELTM 820 DU S.OO S.OO S.OO
99 % Triethanolamine3.003.003.00 3.00 3.00 3.00 UNISPERSETM Blue 0.100.10 0.10 0.10 0.10 0.10 Other Properties of the IVls-gnitn(lf~ of the Property in Composition Number:
Compositions Viscosity' at 20 rpm, cps 2000 1840 1790 1770 2010 1900 Visc~ily~ at S rpm, cps5360 4240 4520 4400 5600 4920 Viscosily' at 1 rpm, cps 9200 10,4009200 15,400 13 600 pH 9.2 9.2 9.2 9.1 9.1 9.1 ~The viscosity was measured at 25 ~C with a Brookfield Viscometer, using Spindle # 4.
-W O g7/2724i PCT~US97/~0007 Use Examples Each working composition defined in Table I was coated over a sample of con-ventional grate plate material for spray paint booths to produce a coating with a wet thie~n.o~s of about 0.20 mil limeters. The coating was then dried at a temperature of 60 ~C for a time of 20 minutes to produce a dry coating according to the invention. Various kinds of paint were caused to accumlate on the thus coated samples, by exposing them r to a laboratory scale paint spray booth, until the coating of paint in its thickest parts was about 0.51 miliimeters thick. The coated samples were then immersed in water at a tem-perature of 93 ~C. Within 30 seconds, breakup and dislodgement of the coating could be obseîved, and this process was completed within 90 seconds. The particles formed by breakup of the protective coating according to the invention and the paint adhered to it were ~kimmed off the top of the water in which the breakup of the coating had oc-curred. The vessel was then emptied and the previously coated metal substrate samples removed. No adherent paint on either the previously coated metal substrate samples or the walls of the vessel in which breakup of the co~ting~ had occurred was observed.
Time and Tel"~ re Variations for ~ryin~ Wet Coatin~s Accordin~ to the Invention In this group of e~anll.les, numerous coated samples of conventional grate material were prepared with a wet coating thickness of about 0.20 millimeters ofComposition No. 20 as shown in Table 1 and subjected to drying conditions as shown in Table 2 below, with the results also shown in Table 2. At the same time as the coated substrates were being exposed to drying conditions as reported in Table 2, a small alllmin1lm pan with a thin layer of the coating composition was exposed to the same drying conditions. Any visually perceptible roughening of the layer of coating, bubbles in the layer, irregularities in thicl!n~, or the like was regarded as evidence of the 2~ be~....;.-g of irreversible expansion ofthe microballoons, which of course is not desired at this stage of a process according to the invention.
CA 02242912 1998-07-lO
W O 97/27241 PCT~US97/00007 Tem- Time of Exposure to Temper~ture7 Minutes:
pera-~ ture, ~C 10 20 30 40 50 60 70 21 VW VW W W W W ex.W ex.E.
E.
32 VW W W ~x. E.D exDr. CD CD CD
43 W ex. E. 90 % D CD CD CD CD CD
54 90 % W 90 % D CD CD CD CD CD
66 75 % W CD CD CD CD CD CD
77 80 % D CD* CD* CD* CD* CD* CD*
88 CD* CD* CD* CD** CD**CD*~CD*~
Abbreviations and Notes for Table 2 VW = very wet; W = wet; ex. E. = except at edges; D = dry; ex. Dr. = except for a few wet drops; CD = completely dry; pc;~ lldges are estim~tecl area percents; * indicates that there was visual evidence of at least the beginning of expansion of the microballoons in the pan sample of the coating composition, but not in the coating on the grate samples;
** indicates that there was visual evidence of at least the beginning of expansion of microballoons in both the pan sample and the coating on the grate substrates; at 21 ~C, which was the ambient t~ ,eldl lre in the laboratory at the time of the tests, the relative humidity was 65 %; at other temperatures, the relative humidity was whatever resulted from heating air at the ambient temperature and humidity to the temperatures shown, without any added water.
Claims (20)
1. A liquid coating composition suitable for applying to a solid surface for producing a thermally releasable barrier coating on the surface, said liquid coating composition consisting essentially of water and:
(A) a component of water soluble polymer material that (i) is solid at 25 °C, (ii) contains at least 1 percent of nitrogen atoms bonded into a chemical moiety selected from the group consisting of amido and quaternary ammonium, and (iii) is solublein water to an extent of at least 5 % at 25 °C and normal atmospheric pressure;
(B) a component of film forming polymer that is not soluble in water to an extent of as much as 4.5 % at 25 °C and normal atmospheric pressure but is stably dispersed in the coating composition; and;
(C) a component of gas filled, polymer walled microballoons having the properties that (i) they are stably dispersed in the coating composition and remain stably dispersed and substantially unexpanded when the coating composition is maintained at a temperature not greater than 65 °C; and (ii) when exposed for at least five minutes to at least one temperature in the range from 80 to 95 °C, they undergo an irreversible expansion, without wall rupture, so as to produce an expanded form which has a density not greater than 0.5 times their density before having expanded; and, optionally, one or more of the following components:
(D) a component of viscosity modifying agent(s) that are not part of any of the previously recited components, (E) a component of solid filler that is not part of any of the previously recited components;
(F) a component of dispersing agent that is not part of any of the previously recited components;
(G) a component of pH adjusting agent and/or corrosion inhibitor that is not part of any of the previously recited components;
(H) a component of coloring agent that is not part of any of the previously recited components; and (J) a component of biocide that is not part of any of the previously recited components, said liquid coating composition having the property that it can be formed into a liquid coating over a metal or plastic substrate solid surface and the thus-formed liquid coating can be converted, by heating the liquid film in place on the substrate to a temperature not greater than 65 °C under normal atmospheric pressure for a time not greater than one hour, into a coherent solid coating that adheres to the substrate.
(A) a component of water soluble polymer material that (i) is solid at 25 °C, (ii) contains at least 1 percent of nitrogen atoms bonded into a chemical moiety selected from the group consisting of amido and quaternary ammonium, and (iii) is solublein water to an extent of at least 5 % at 25 °C and normal atmospheric pressure;
(B) a component of film forming polymer that is not soluble in water to an extent of as much as 4.5 % at 25 °C and normal atmospheric pressure but is stably dispersed in the coating composition; and;
(C) a component of gas filled, polymer walled microballoons having the properties that (i) they are stably dispersed in the coating composition and remain stably dispersed and substantially unexpanded when the coating composition is maintained at a temperature not greater than 65 °C; and (ii) when exposed for at least five minutes to at least one temperature in the range from 80 to 95 °C, they undergo an irreversible expansion, without wall rupture, so as to produce an expanded form which has a density not greater than 0.5 times their density before having expanded; and, optionally, one or more of the following components:
(D) a component of viscosity modifying agent(s) that are not part of any of the previously recited components, (E) a component of solid filler that is not part of any of the previously recited components;
(F) a component of dispersing agent that is not part of any of the previously recited components;
(G) a component of pH adjusting agent and/or corrosion inhibitor that is not part of any of the previously recited components;
(H) a component of coloring agent that is not part of any of the previously recited components; and (J) a component of biocide that is not part of any of the previously recited components, said liquid coating composition having the property that it can be formed into a liquid coating over a metal or plastic substrate solid surface and the thus-formed liquid coating can be converted, by heating the liquid film in place on the substrate to a temperature not greater than 65 °C under normal atmospheric pressure for a time not greater than one hour, into a coherent solid coating that adheres to the substrate.
2. A composition according to claim 1, wherein, with all percentages based on the total composition unless otherwise stated: component (A) is present in an amount from about 1.0 to about 30 %; component (B) is present in an amount from about 1.0 to about 30 %; components (B) and (A) are jointly present in amounts having a ratio of the amount of component (B) to the amount of component (A) that is from about 0.30:1.0 to about 4.0: 1.0; the microballoons of component (C) have an average diameter between about 3 and about 100 µm; the amount of component (C) is from about 1.0 to about 20 %; and the composition has a viscosity that is at least 3000 cps when measured at 1 rpm, at least 2000 when measured at 5 rpm, and not more than 6000 when measured at 20 rpm.
3. A composition according to claim 2, wherein: the amount of component (A)is from about 2.0 to about 25 %; the amount of component (B) is from about 2.0 to about 25 %; the ratio of component (B) to component (A)is from about 0.40:1.0 to about3.5:1.0; the microballoons of component (C) have an average diameter between about 4 and about 70 µm; the amount of component (C) is from about 2.0 to about 15 %; the viscosity of the composition is at least 4000 cps when measured at 1 rpm, at least 2250 when measured at 5 rpm, and not more than 5000 when measured at 20 rpm; and component (E) is present in a volume that corresponds in mass to from about 5 to about 50 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7.
4. A composition according to claim 3, wherein: component (A)is selected from the group consisting of polymers of amides of unsaturated carboxylic acids; the amount of component (A) is from about 3.0 to about 20 %; component (B) is selected from the group consisting of copolymers of (i) vinyl esters of carboxylic acids with not more than four carbon atoms per molecule and (ii) at least one of the group consisting of acrylic and methacrylic acids and esters of both these acids; the amount of component (B) is from about 3.0 to about 20 %; the ratio of component (B) to component (A)is from about 0.50:1.0 to about 3.0:1.0; the microballoons of component (C) have an average diameter between about 5 and about 50 µm; the amount of component (C) is from about 3.0 to about 10 %; the viscosity of the composition is at least about 7000 cps when measured at 1 rpm, at least about 2500 cps when measured at 5 rpm, and not more than about 4000 cps when measured at 20 rpm; component (E) is present in a volume that corresponds in mass to from about 8 to 45 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 40 % of the total amount of component (E) is made up of particles with a size between 4 and 50 µm.
5. A composition according to claim 4, wherein: the amount of component (A) is from about 3.5 to about 15 %; the amount of component (B) is from about 3.5 to about 15 %; the ratio of component (B) to component (A) is from about 0.60:1.0 to about 2.5:1.0; the microballoons of component (C) have an average diameter between about 6 and about 40 µm; the amount of component (C) is from about 3.5 to about 8.0 %; the viscosity of the composition is at least about 9000 cps when measured at 1 rpm, at least about 2750 cps when measured at 5 rpm, and not more than about 3750 cps when measured at 20 rpm; component (E) is present in a volume that corresponds in mass to from 10 to 40 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 50 % of the total amount of component (E) is made up of particles with a size between 5 and 40 µm.
6. A composition according to claim 5, wherein: the amount of component (A) is from about 4.0 to about 10 %; the amount of component (B) is from about 4.0 to about 10 %; the ratio of component (B) to component (A) is from about 0.70:1.0 to about 2.0:1.0; the microballoons of component (C) have an average diameter between about 7 and about 30 µm; the amount of component (C) is from about 4.0 to about 7.0 %; the viscosity of the composition is at least about 10,000 cps when measured at 1 rpm, at least about 3000 cps when measured at 5 rpm, and not more than about 3500 cps when measured at 20 rpm; component (E) is present in a volume that corresponds in mass to from 11.0 to 35 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 50 % of the total amount of component (E) is made up of particles with a size between 5 and 40 µm.
7. A composition according to claim 6, wherein: the amount of component (A) is from about 4.5 to about 9.0 %; the amount of component (B) is from about 4.5 to about 9.0 %; the ratio of component (B) to component (A) is from about 0.80:1.0 to about 1.7:1.0; the microballoons of component (C) have an average diameter between about 8.0 and about 25 µm; the amount of component (C) is from about 4.0 to about 6.5 %; the viscosity of the composition is at least about 10,000 cps when measured at 1 rpm, at least about 3250 cps when measured at 5 rpm, and not more than about 3250 cps when measured at 20 rpm; component (E) is selected from the group consisting of water-insoluble mineral talcs, clays, and carbonates and is present in a volume that corresponds in mass to from 12.0 to 30 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 60 % of the total amount of component (E) is made up of particles with a size between 6 and 30 µm.
8. A composition according to claim 7, wherein: the amount of component (A) is from about 4.8 to about 8.5 % ; the amount of component (B) is from about 4.9 to about 8.5 % ; the ratio of component (B) to component (A) is from about 0.90:1.0 to about 1.3: 1.0; the microballoons of component (C) have an average diameter between about 9.0 and about 22 µm; the amount of component (C) is from about 4.0 to about 6.0 %; the viscosity of the composition is at least about 11,000 cps when measured at 1 rpm, at least about 3500 cps when measured at 5 rpm, and not more than about 3100 cps when measured at 20 rpm; component (E) is present in a volume that corresponds in mass to from about 13.0 to about 25 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 70 % of the total amount of component (E) is made up of particles with a size between 7 and 25 µm.
9. A composition according to claim 8, wherein: the amount of component (A) is from about 5.2 to about 8.0 %; the amount of component (B) is from about 5.3 to about 7.5 %; the ratio of component (B) to component (A) is from about 0.95:1.0 to about 1.3:1.0; the microballoons of component (C) have an average diameter between about 9.0 and about 20 µm; the amount of component (C) is from about 4.0 to about 5.5 %; the viscosity of the composition is at least about 12,000 cps when measured at 1 rpm, at least about 4000 cps when measured at 5 rpm, and not more than about 3100 cps when measured at 20 rpm; component (E) is present in a volume that corresponds in mass to from about 14.0 to about 22 % of the total of components (A) and (B) for a solid with a specific gravity of 2.7; and at least 80 % of the total amount of component (E) is made up of particles with a size between 8.0 and 20 µm.
10. A composition according to claim 8, wherein: component (A) is selected from the group consisting of polymers of acrylamide; the amount of component (A) is from about 5.8 to about 6.2 %; component (B) is selected from the group consisting of copolymers of (i) vinyl acetate and (ii) at least one of the group consisting of esters of acrylic and methacrylic acids with alcohols containing not more than four carbon atoms; the amount of component (B) is from about 6.3 to about 6.9 %; the ratio of component (B) tocomponent (A) is from about 1.05: 1.0 to about 1.2: 1.0; the microballoons of component (C) have an average diameter between about 10 and about 20 µm; the amount of component (C) is from about 4.5 to about 5.1 %; the viscosity of the composition at 25 °C is at least about 13,500 cps when measured at 1 rpm, at least about 4900 cps when measured at 5 rpm, and not more than about 3100 cps when measured at 20 rpm; component (E) is talc with a specific gravity of 2.7 and is present in an amount from about 15.0 to about 16.2 % of the total of components (A) and (B); and at least 90 % of the total amount of component (E) is made up of particles with a size between 10.0 and 16 µm.
11. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 10, said liquid coating having a thickness corresponding to from about 30 to about 35 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), by heating the liquid coating for a time from about 19 to about 21 minutes at a temperature from about 59 to about 61 °C, to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 10, said liquid coating having a thickness corresponding to from about 30 to about 35 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), by heating the liquid coating for a time from about 19 to about 21 minutes at a temperature from about 59 to about 61 °C, to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
12. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 9, said liquid coating having a thickness corresponding to from about 25 to about 40 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), by heating the liquid coating for a time from about 15 to about 25 minutes at a temperature from about 55 to about 65 °C, to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 9, said liquid coating having a thickness corresponding to from about 25 to about 40 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), by heating the liquid coating for a time from about 15 to about 25 minutes at a temperature from about 55 to about 65 °C, to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
13. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 8, said liquid coating having a thickness corresponding to at least about 20 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 8, said liquid coating having a thickness corresponding to at least about 20 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
14. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 7, said liquid coating having a thickness corresponding to at least about 20 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 7, said liquid coating having a thickness corresponding to at least about 20 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
15. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 6, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 6, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
16. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 5, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 5, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
17. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 4, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 4, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
18. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 3, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 3, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
19. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 2, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 2, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (I), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
20. A process comprising steps of:
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 1, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (1), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
(I) forming on a substrate surface to be protected against accumulation of paintthereon a liquid coating of a coating composition according to claim 1, said liquid coating having a thickness corresponding to at least about 12 µm of constituents of the liquid coating composition that remain present after the liquid coating is heated to 65 °C for at least one hour; and (II) drying the liquid coating formed in step (I), while said coating is in place over the substrate surface as formed in step (1), for a sufficient time at a sufficient temperature to convert the liquid coating to a solid adherent coating over those portions of the substrate surface that were provided with a liquid coating in step (I), without causing irreversible expansion of the gas filled, polymer walled microballoons present in the solid coating.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/591,992 US5935655A (en) | 1996-01-26 | 1996-01-26 | Thermally releasable barrier coating, composition therefor, and use thereof |
| US08/591,992 | 1996-01-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2242912A1 true CA2242912A1 (en) | 1997-07-31 |
Family
ID=24368810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002242912A Abandoned CA2242912A1 (en) | 1996-01-26 | 1997-01-09 | Thermally releasable barrier coating, composition therefor, and use thereof |
Country Status (11)
| Country | Link |
|---|---|
| US (1) | US5935655A (en) |
| EP (1) | EP0876424A4 (en) |
| JP (1) | JP2000505828A (en) |
| KR (1) | KR19990082018A (en) |
| AR (1) | AR005518A1 (en) |
| AU (1) | AU712706B2 (en) |
| BR (1) | BR9707193A (en) |
| CA (1) | CA2242912A1 (en) |
| TR (1) | TR199801416T2 (en) |
| WO (1) | WO1997027241A1 (en) |
| ZA (1) | ZA97453B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4019594A1 (en) | 2020-12-22 | 2022-06-29 | Christoph Dirks | Wall paint with reduced weight |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1427773A1 (en) * | 2001-09-21 | 2004-06-16 | Dow Corning Toray Silicone Co., Ltd. | Electroconductive silicone rubber sponge |
| US6872761B2 (en) * | 2003-04-24 | 2005-03-29 | Henkel Kommanditgesellschaft Auf Aktien | Compositions for acoustic-damping coatings |
| US6869475B1 (en) | 2003-10-28 | 2005-03-22 | Bnz Materials, Inc. | Calcium silicate insulating material containing blast furnace slag cement |
| US8709141B2 (en) * | 2007-03-02 | 2014-04-29 | Ppg Industries Ohio, Inc. | Heat releasable composite coatings and related methods |
| CN101821091B (en) | 2007-10-10 | 2014-01-29 | 3M创新有限公司 | Articles and methods of masking or protecting a substrate |
| FR3099933B1 (en) | 2019-08-12 | 2023-05-26 | Rescoll | Compositions removable by thermal activation, uses and assemblies comprising such compositions |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4464416A (en) * | 1981-03-11 | 1984-08-07 | The United States Of America As Represented By The Depart Of Energy | Method of forming metallic coatings on polymeric substrates |
| US4844833A (en) * | 1986-01-28 | 1989-07-04 | Kaken Kogyo, Co., Ltd. | Paint peeling composition and paint peeling method |
| US5017303A (en) * | 1986-01-28 | 1991-05-21 | Kaken Tech Co., Ltd. | Paint peeling composition and paint peeling method |
| US4867900A (en) * | 1987-03-05 | 1989-09-19 | Kaken Kogyo, Co., Ltd. | Paint peeling composition |
| US5010131A (en) * | 1989-10-20 | 1991-04-23 | Texo Corporation | Barrier coating |
| JP2808211B2 (en) * | 1992-06-09 | 1998-10-08 | 東陶機器 株式会社 | Continuous pore porous body and pressure casting mold for porcelain using the porous body |
-
1996
- 1996-01-26 US US08/591,992 patent/US5935655A/en not_active Expired - Fee Related
-
1997
- 1997-01-09 EP EP97901903A patent/EP0876424A4/en not_active Withdrawn
- 1997-01-09 BR BR9707193A patent/BR9707193A/en not_active Application Discontinuation
- 1997-01-09 CA CA002242912A patent/CA2242912A1/en not_active Abandoned
- 1997-01-09 AU AU15704/97A patent/AU712706B2/en not_active Ceased
- 1997-01-09 TR TR1998/01416T patent/TR199801416T2/en unknown
- 1997-01-09 JP JP9526854A patent/JP2000505828A/en active Pending
- 1997-01-09 KR KR1019980705738A patent/KR19990082018A/en not_active Application Discontinuation
- 1997-01-09 WO PCT/US1997/000007 patent/WO1997027241A1/en not_active Application Discontinuation
- 1997-01-20 ZA ZA9700453A patent/ZA97453B/en unknown
- 1997-01-22 AR ARP970100258A patent/AR005518A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4019594A1 (en) | 2020-12-22 | 2022-06-29 | Christoph Dirks | Wall paint with reduced weight |
Also Published As
| Publication number | Publication date |
|---|---|
| TR199801416T2 (en) | 1998-10-21 |
| AU1570497A (en) | 1997-08-20 |
| BR9707193A (en) | 1999-04-06 |
| US5935655A (en) | 1999-08-10 |
| KR19990082018A (en) | 1999-11-15 |
| EP0876424A1 (en) | 1998-11-11 |
| WO1997027241A1 (en) | 1997-07-31 |
| AR005518A1 (en) | 1999-06-23 |
| JP2000505828A (en) | 2000-05-16 |
| AU712706B2 (en) | 1999-11-11 |
| EP0876424A4 (en) | 2002-01-23 |
| ZA97453B (en) | 1997-07-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |