CA2107579A1

CA2107579A1 - Low voc cleaning compositions and methods

Info

Publication number: CA2107579A1
Application number: CA002107579A
Authority: CA
Inventors: Douglas J. Bosscher; Carol E. Hendrickson
Original assignee: Individual
Current assignee: 3M Co
Priority date: 1991-04-10
Filing date: 1992-04-06
Publication date: 1992-10-11
Also published as: EP0580721B1; EP0580721A1; DE69217486T2; WO1992018600A1; JPH06506496A; DE69217486D1

Abstract

A method of removing residue from hard surfaces utilizes an oil-in-water microemulsion by applying to such surfaces an effective amount of a composition comprising an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9 (cal/cm3)1/2, sufficient surfactant to support a stable microemulsion, and water in an amount sufficient to provide a total VOC
content of less than 200 grams/liter. The microemulsion is allowed to soften and otherwise ease removal of the silicone wax, grease, grime, and the like from the surface. The microemulsion and the residue to be cleaned from the surface are removed from the surface by wiping with a dry wiping material. Compositions are also provided.

Description

~ ~ 33 {f ;~ ~ 3 LO~ VOC CLEANI~G COMPO8IT~ON8 AND ME~EODS

BACKGROUND
Field of Invention This invention relates to compositions and methods for removing silicone wax, grease, grime, adhesives and the like from hard surfaces such as lO automobile finishes.

Descr Ption of the Art Currently, contaminants are removed ~rom hard surfaces such as automobile finishes with cleaning 15 fluids that are predominately organic solvents. These solvents are now being regulated because of their ef~ect on air quality. Specifically, the South Coast Air Quality Management District and Bay ~reas of California have issued rules defining the amount of 20 Volatile Organic Compounds ~VOCs~ which may be present in certain materials whose vapors may be discharged into the atmosphere. Additional~y, organic solvents ~u~far from the disadvantage that they may evaporate before there is an opportunity to wipe it off. :
25 Premature evaporation may leave soil residues on the surface to be cleaned.
U.S. Patent No. 4,446l044 to Rutkiewic, et.
al. describes a water-in-oil emulsion, used as a cleaning fluid for automotive finish surfaces.
30 Rutkiewic, et. al. make the explicit statement at column 3, lines 23-26 that "in order for this particular emulsion to be efficacious as a cleaner, it is necessary that the water, not the organic solvent, constitute the internal phase." This suggests that the 35 emulsion must be o~ the water-in-oil type for effective cleaning~
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WO92/18600 PCT/~S92/02760 ~ ~75 1~ - 2 - , U.S. Pat~nt No. 3,983,047 to Vinson describes a decal removal composition for loosening adhesive bonded to an airplane. The composition contains mostly organic sol~ent well above the regulated VOC limit and 5 is a solvent mixture.
U.s. Patent No. 4 ,146, 499 to Rosano discloses a method of preparing microemulsions for a wide variety of applications including the use of hydrophobic substance such as hydrocarbon substances including 10 mineral spirits for "their ability to dissolve most hydrophobic substance."
U.S. Patent No. 4,909,962 to Clark describes a composition used primarily for laundry pre-spotting that is a microemulsion comprising organic solvent and 15 a selection of nonionic surfactants and cosolvents.
Component C of this composition is a supplementary nonionic surfactant comprising an amine oxide or an alkyl phenol ethoxylate. See especially col~ 2, line 59 and Examples 7 and 8 at colO 8. These compositions are 20 specifically intended to be used on fabrics that will be followed by a regular washing, thereby infinitely diluting the composition with a water ratio of at least ~- -100 parts water to 1 part composition. The optional use of these compositions as all-purpose cleaners for 25 hard surfaces is disclosed at column 3, lines 21 to 30.
U.S. Patent No. 4,370,174 to Brathwaite, Jr.
discloses a method for removing adhesive residues using an emulsion cleaner. The composition used comprises an organic solvent, a minor amount of an inorganic solid 30 absorbent powder, an water-in-oil surfactant and an oil-in-water surfactant sufficient to reverse the emulsion to a~water external phase upon addition of water. The emulsion was initially provided in an oil external phass because it was believed that this was 35 nec~-ssary to insure that the organic solvent was exposed to the adhesive residue. These compositions are applied to flooring sur~aces as a preparation for subsequent application of adhesives. The compositions ' :.
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are poured directly on the surfac~- to be cleaned and allo~ed to dissolve the adhesive r about lO to 30 minutes.
There is a need in the art for a composition 5 to clean difficult-to xemove contaminants fxom hard surfaces safely while at the same time satisfying stringent VOC requirements. Such compositions preferably should be easily removed from the surface to be cleaned so as not to leave any residue. Water-based lO cleaners may be washed ~rom the surface to be cleaned l ~-with excess water, but this is undesirable because this process requires an additional step and can leave water running from the interstices of joints in the structure that must be dried before painting. Water flushing is 15 particularly undesirable when cleaning automobile surfaces for refinishing.
:,, Summary of the Invention The present invention provides a method of 20 removing silicone wax, grease, grime, adhesives and other such residues from hard surfaces such as tile, windows, plastic, ~etal and painted surfaces with an oil~ water microemulsion comprising applying to such surfaces an effective amount of a composition 25 comprising an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9 (cal/cm3)l/2, su~ficient surfactant to support a stable microemulsion, and water in an amount sufficient to provide a total VOC content of less than 200 30 grams/liter. The microemulsion is allowed to so~ten and otherwise ease removal of the silicone wax, grease, grime, and the like from the surface. The microemulsion and the residue may be removed from the surface by wiping with a dry wi~ing material.
The microemulsion used in the present method yields surprising cleaning power with a small amount of volatile organic solvent, and without the need ~or ','',.:'' .

; ... .

W ~ 92/1~600 PC~r/US92/02760 .. ` .

large amounts of detergent, harsh pH conditions or the like.

DetAiled Description of Presently Preferred Embodiments The method of the present invention is specifically adapted to the particular perfo~mance requirements of the operation to be performed~ Thus, where the surface to be cleaned is soiled by oil, grPase, wax or the like and is to be repainted or 10 otherwise refinished, it is particularly important to provide cleaning that will leave no trace of residue of either the soil or the cleaning agent itself. Such cleaning is particularly important in the repainting of automobile surfaces. Such residues will lead to "fish 15 eyes," or noticeable bumps in the painted surface. ~he microemulsion, when used in accordance with the present invention, may be applied to the surface to be treated and effectively wiped away using only a dry wiping material. No additional cleanup, such as a water wash, 20 is required to remove any trace cleaner. When a surface that is soiled with adhesive is to be cleaned, the standard of desired cleaning may not need to be as high as for surfaces to be repainted, because adhesive will likely be applied to the same surface. In such 25 applications, however, good cleaning is still important to avoid adhesive failure due to adhesive or surfactant residue remaining on the sur~ace. Here again, the microemulsion is applied to the surface to be treated and effectively wiped away using only a dry wiping 30 material without additional cleanup.
The oil-in-water microemulsion used in the present invention provides good cleaning action while at the same time satisfying environmental standards for VOCs. The organic solvent also does not evaporate 35 rapidly because it is contained within discontinuous droplets distributed in the continuo-~s aqueous phase, and is not present in quantity at the liquid-air inte~phase. The lower evaporation rate of the organic ~-~
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W~92/18600 PCT/US92/02760 _ 5 _ solvent is further advantageous, because tenacious waxy or adhesive residues are allowed to soak in the solvent prior to removal. Environmental compatibility o~ the present microemulsion may be further improved with the 5 choice o~ nontoxic organic components and biodegradable surfactants. Judicious choice of components also may render the microemulsion nonflammable for easier compliance with shipping regulations.
Residue may be more easily removed from the 10 surface to be cleaned using the present oil-in-water microemulsions by simple dry wiping techniques than using a solvent-based or water-in-oil based system. If desired, the present microemulsion may alternatively be removed by water washing techniques, because the 15 microemulsion is water-dilutable. Water washing is not practical in solvent-based or water-in-oil based systems. Ease in cleanup provides significant advantages both in labor-saving and a more acceptable final prod-~ct.
The microemulsion used in the present invention is an oil-in-water microemulsion. Such ~ `
microemulsions typically contain dispersed droplets of oil in the range of 50-1500A in diamater, which is visibly transparent or translucent. The microemulsion Z5 is formed spontaneously, i.e., without any energy input, with the proper selection of oil, water and surfactant components.
The organic solvent component of the microemulsion i5 an organic solvent or solvent blend 30 having a solubility parameter of between about 6.9 and 8.9. The specific solvent or solvent blend and the concentration of the æolvent to be used is selected on the basis of the proposed application. In case of applications of cleaning silicone wax, grease, grime or ;`
35 the like, a low concentration of a mild hydrocarbon such as odorless mineral spirits is most suitable for cost concerns and mi~imal effect on fresh paint finishes. In case of adhesive remover applications or "`
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W092/18600 PC~/US92/02760 2 ~ ~ 7 3 ~ ~ - 6 -other such applications where a more aggressi~e cleaning action is required, a higher concentration of a more aggressive organic solvent or solvent blend is preferred. The solvent selected should preferably have 5 a solubility parameter of bet~een about 7 5 and 8.9 (cal/cm3~l/2. Preferred aggressive solvents or solvent blends comprise at least 5% by weight of the solvent ingredient of a polar or aromatic component. Examples of such a polar component include butyl acetate, lO acetone, glycol ether, alcohols or the like. The aromatic component may be toluene, xylene, naphthalene or the liXe.
Suitable microemulsions typically comprise:
a) an organic solvent or solvent blend 15 having a solubility parameter of ~etween about 6.9 and 8.9 tcal/~m3)1/2 b) sufficient nonionic surfactant or surfactant blend to maintain a microemulsion, and c) water in an amount sufficient to provide ~o a total vac content of less than 200 grams/liter.
More typically, the microemulsion comprises a blend of surfactants to enhance stability of the composition. Blends of sur~actants are generally more efficient in providing stability, and thus need not be 25 provided in as large amounts as a single surfactant.
The surfactants typically are of diverse chemical classes, selected from cationic, zwitterionic, anionic and nonionic surfactants. Preferabl~, the surfactants are selected from the nonionic surfactants, together 30 with another surfactant selected from cationic, ~ ~
zwitterionic and anionic surfactants. -The combination of cationic or zwitterionic surfactants with nonionic surfactants provides a wide range of temperature stability to the microemulsion and 35 a low surfactant concentration.
The surfactants serve both as emulsifiers and, ~o some extent, as cleaning agents. The surfactant combination is preferably chosen based on ::
.

W092/1~600 PCT/US92/02760 ~ ~æ ~ -J Y ~
its removability from the surface or compatibility with subse~uently applied pa ItS and biode.gradability. The preferred HLB of the nonionic surfactant is determined by the choice of organic solvent components and is 5 selected to be higher than 7 to enable a spontaneously ~-formed oil in-water emulsion.
Cationic or zwitterionic surfactants, such as amines and their salts, quaternary an~onia salts, amine -~
oxides, or other cationic sur~actants known in the art, lO may be used. Alkylamine oxides, such as cocadimethylamin~ oxide or lauryldimethamine oxide, are pre~erred because of their low toxicity.
Typical nonionic surfactants that may be used in the microemulsions of the present invention inlude 15 the polyoxyethylene surfactants, such as polyethoxylated alkyphenols and polyethoxylated linear or branched primary or secondary alcohols; the carboxylic acid esters, such as glycerol esters, polyoxyethylene esters, ethoxylated anhydrosorbitol :
20 esters, ethoxylatied natural fats, oils and waxes and glycol esters of fatty acids; the carboxylic amides, : such as diethanolamine condensates, monoalkanolamine condensates, polyoxyethylene fatty acid amid~s; and the :
polyalkylene oxide block copolymers, such as PluronicTM
25 line o~ sur~actants from BASF Corp. Polyethoxylated :: .
linear alcohols, such as Neodal~M manu~actured by Shell Chemicals an~ TergitolTM manufactured by Union Carbide Company, are preferred as most biodegradable.
Most preferably, the microemulsion also ::
30 comprises a co surfactant to aid the solubilization of . :~
the surfactants in the solvent, to minimize gelation during phase transition, and to provide transparency ~
and low viscosity of the microemulsion. The . ~ :
co-surfactant i6 chosen based on its polarity as well : :
35 as low toxicity and flammability. Mid chain length alcohols; such as n-propanol, n-butanol, pentanol, glycols; such as propylene glycol, or glycol ethers; .. :
such as dipropylene glycol methyl ether, diethylene ' ':
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WO92JlB600 PCT/VS92/02760 8 ~
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glycol butyl ether, propylene glycol methyl ether, ethylene glycol butyl ether can be used. The use of an alcohol which also acts as a solvent is additionally advantageous especially in case of the adhesive remover 5 application. An inflammable, low toxi.c glycol ether, such as dipropylene monoethyl ether, is preferred especially in the adhesive remover fo~ulation which has a higher concentration or organic components.
To formulate experimental microemulsions lO according to the present invention, the solvent or solvent blend is mixed with an amount of cosurfactant equal or slightly less than the amount of surfactant to be used in the ultimate composition. The cationic and nonionic surfactants are added to the solvent mixture, 15 and the resultant mixture stirred well. Water is added in aliquots with gentle stirring after each addition until the viscosity has increased and subsequently decreased to indicate a phase transition from water~ oil to oil-in-water. From this point on, 20 water can be added rapidly in an amount to provide the concentration desired.
The appropriate ratio of surfactants and amount of cosurfactant is determined through routine experimentation, reducing the amount of comparatively 25 expensive ingredients as taught herein as possible for the particular solvent or solvent blend used. ~he ratio o~ cationic to nonionic surfactant can be adjusted to minimize the total amount of necessary surfactant. Generally, when less cationic surfactant 30 is used, the total amount of surfactant must be increased. The cosurfactant is preferably add~d before the addition of water because it aids the solubilization of the surfactants in the solvent and minimizes gelation during the phase transition. The 35 amount of cosurfactant to be used is adjusted to provide transparency and low viscosity. If the amount of necessary cosurfactant exceeds the desired VOC, the formulation is adjusted by changing the ratios of ~- `

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- ;urfactants in the ~rmulation. Once the ratio of surfactant and cosurfactant has been established, the concentrat ~n of each component can be lowered or raised in relationship to the solvent to optimize 5 stability and performan~e.
Once a satisfactory formulation for the microemulsion has been determined, u~ually no special techniqlles for mixing are required. A11 of the ingr~dients may be added in any order and mixed to form 10 the microemulsion as taught h~rein.
~referred microemulsions comprise by weight:
a) 5-15% of an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9 (cal/cm3)1/2, b) 8-12~ of a cationic or zwitterionic surfactant, c) 4-8% of a nonionic surfactant or surfactant blend having an HLB of between about 7O5 and `
10, " , d) 1-5% of a co-surfactant, and e) 50-82% of water, such that the total VOC
content of the microemulsion is less than 200 grams/lit2r.
Where the microemulsion is to be used for 25 cleaning silicone wax, grease, grime, and the like from hard surfaces to be repainted, a milder, less expensive yet effective cleaning solution is preferably provided by a composition comprising by weight:

30 5-8% aliphatic organic solvent, 1-3% co-surfactant, 3-5% amine oxide surf ctant, -~
2-4% nonionic surfactant having an H~B
of between 7.5 and 10, and 35 80-89~ deionized water to total 100%.
, Where the microemulsion is to be used for cleaning adhesives from hard surfaces, a ~itronger WO 92/18600 PCI`/US92/02760 . .~
?,~Q;~IA7~ - lO -cleaning solution is pre:Eerably provid~d by a composition comprising by weight:

12-15~ organic solvent having at least 5%
aromatic or polar components, 1-4% co-surfactant, 8-12% amine oxide surfactant, 5-7% nonionic surfactant having an HLB
of between 7.5 and 10, and --lo 62-74% deionized water to total 100%.

The microemulsion can be applied wit~ a pump spray, aerosol, or by wiping a rag, or preferably a highly absorbent, nonwoven pad, which can be rubbed 15 onto the surface to be cleaned. Because of its low volatility, the microemulsion can be left on the surface to soak the contaminant if necessary. A clean rag or nonwoven pad can be used to wipe up the dissolved soil or, optionally, the surface can be 20 rinsed with water. To assure that all of the residue is actually removed and not merely redeposited on drying of the cleaner, physical wiping of the substrate is preferred. The characteristics of the wiping material are chosen to act as a carrier for the 25 application of the microemulsion to the surface to be cleaned. This material must be soft enouyh as not to scratch the surface, non-linting and absorbent enough to hold sufficient quantities of soil/microemulsion.
The preferred wiping material is a surfactant treated 30 polypropylene nonwoven wiper.
Adhesive can be quckly removed if its bulk has been preYiOUSly removed mechanically. Preferably, the bulk of the adhesive is removed with a 3M Striping and Moldiny Adhesive Removal Disc, which is a 35 commercially available elastomeric disc that is rotatable about its axis. Thése disks rub off adhesive residues without harming the underlying finish by frictional contact with the peripheral surface of the WO92/18600 PCT/USs2/0276~
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disk. During the removal of adhesivP ~itep, a portion of the peripher~l surface o~ the disk is attribut~d to provide a renewed peripheral surface of the elastomer.
After cleaning with the emulsion according to the 5 method of the present invention, the surface is surprisingly clean and requires no further cleaning step before repainting or reapplying decals, molding, striping, etc.
The ~ollowing non-limiting examples are lO provided to illustrate the present invention.

. .

A transparent microemulsion was prepared by combining the following ingredients and stirring.
6.1 wt% Odorless Mineral Spirits (Unocal 1241, Union Oil Co.~ Unocal Corporation.
1.5 n propanol 4.4 Mackamine LO 30% active ~a laurylamine oxide surfactant from McIntyre C~em Co.) 2.4 Tergitol 15-S~3 (a nonionic surfactant from Union Carbide Corporation) 85.5 deionized water -A transparent microemulsion was prepared by 30 combining the ~ollowing ingredients and stirring.

14.2 wt% Unocal 75 Mineral Spirits (Union Oil Co.) 5.6 Dipropylene glycol methyl ether 13.0 Mackamine LO 30~ active '.
, .

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'i ' ~' 6.0 Neodal 23-3 (a nonionic surfactant from Shell Oil co.) 61.2 deionized water .

The composition of example 3 was used to - remove the following adhesives baked 150 F three hours onto a painted test panel that is a cold rolled steel panel painted with a base coat/clear coat paint system 10 ~rom DuPont, commercially available from Advanced Coating Technology, I~c.

ScotchMount 06378 . ScotchMount 06381 ScotchCal A~
. 3M Weather Stripping ..
Adhesive 08011 3M General Trim Adhesive .
$ ~
j 20 These adhesives represent acrylate, styrene butadiene, and Neoprene type adhesives. The bulk of adhesive was removed with the SCOTCH-BRITE Molding : :
~, A~hesive and Stripe Removal Discs, deliberately leaving ~ .
. white smears o~ adhesive to better challenge the ::
25 microemulsion adhesive cleaner. A hand size pad of nonwoven material as moistened with the microemulsion and rubbed for a maximum of five minutes or until the :
adhesive was removed from an approximate 3~5 square ~ inch area.
:~ 30 The following microemulsions were prepared ~ .
and used to remove the following adhesives a~ter the . bulk of adhesive was removed with 3M Striping and 35 Molding Adhesive Removal Discs. Smears of adhesive were deliberately left on the surface to be cleaned to . ~
better challenge the power of the microemulsion ::
adhesive remover. .~
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WO 92/18600 PC~/US92/02760 p,~ ,,~, .

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a 4 ~D ,i l ~ l l ~D ~ ¦ ~ x ~ V
,~,, Ix~ ~ s~
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,~, x O ~ ~ O t~ co o o a U ,~ ~ ~h,, ~ 4 0~O I ~ I ~ 8 ~ ~oo~ ~
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O~ ~ ~ l ~ V~ 0 ~ ' . ~ R O
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W092/~600 PCT/US92/0276 This example shows the variety of organic solvents that can be microemulsified with this basic formulation and their comparative e~ficiencies.

The following microemulsions were prepared using 14.2 wt. ~ Unocal 75 solvent, the surfactants listed below and the balance o~ water.
. .
Amount of Each Com~onent in weiqht %

Cosurfactants Surfactant 1 Surfactant 2 a) Propylene Triton Mackamine ~ .
Glycol 4.4 N-57 6.0 LO 7.6 .
b) DiPropylene Triton Mackamine : :
Glycol 4.6 M-57 6.0 LO 7.6 ~ .
c) Diethylene 20Glycol Triton Mackamine butyl ether 3.5 N-57 6.0 LO 6.0 d) N-propanol 3.6 Triton Mackamine : ; -N-57 6.0 LO 7.6 The following microemulsions were prepared using several more biodegradabl~ nonionic sur~actants and balanoed with water. ::.
In the table below, the abbreviations are:
U75 = Unocal 75, 7.5% aromatic mineral spirits :
commercially available from Unocal Corporation.
U1241 - Unocal 1241, odorless mineral spirits ~ :
commercially available from Unocal Corporatio DPM = dipropylene ylycol methyl ether. :
n-pro = n-propanol.
T15-S-3 -- Triton 15-S-3, a nQnionic surfactant ~rom Union Carbide Corporation.
Neo 91-6 = Neodal 91-6, a nonionic sur~actant frGm Shell Oil Co. ;~
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~ tt~ 73 T15-S-5 = Triton 15-S-5, a nonionic surfactant from Union Carbide Corporation.
Neo 23-3 = Neodal 23-3, a nonionic sur~actant from Shell Oil Co.
Amount in weiqht %
_ _ _ . _ __ .
Oil co~urfactant Macka-~ur~act~nt surfactant U7514.2 DPM 5.6 13.6T15-5-3 ~ B
_ .. _ _, _ . . _ . _ `; ~ ' ~7514.2 DPM 4.5 10.0~15-S-5 12 O
__ _ _ _ . __ _ U75 14.2 DPM 5.6 10.2 Neo91-6 0.5 Neo23-2 i~
_ _ . . _ . _ . ~ .
U7514.2 DPM5.6 13.0 Neo23-3 6.0 0 l _ . ___ _. ,.
U1241 6.7n-pr~ 1.5 4.4 T15-S-3 2.4 0 l _ _ _ _._ .
U12~1 6.2n-pro 1.5 4.4 Neo~3-3 2.4 0 l__ _ _ =_ TEST PROTOCOL

The ability of compositions to clean a silicone and wax contaminated automobile panel was evaluated by the following technique. Commercial 20 silicone andlor wax containing polishes were applied to painted panels according to directions of the manufacturer to provide a contaminated sur~ace. The microemulsion was applied to a clean, dry pad, wiped onto the contaminated surface and wiped off with a 25 second clean, dry pad. The panel was then repainted and the quality of the paint finish evaluated by counting the number of ~fish eye" caused by poor filming and adhesion and by the cross-hatch adhesion test ~ASTM D3359). A control section was cleaned by 30 DiFZ1er DX330, a commercial, pure solvent prep solvent.

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Panel~re~paratlon - 16 -Painted steel panels, 25.4 cm x 122 cm, were waxed with either DuPont Rain DanceTM paste wax or 3M
Liquid Polish, PN 05993. The waxed panels were 5 conditioned at room temperature for 7 days. Panels were then taped off with 2.54 cm wide plastic tape into separate 22 cm x 28 cm sections, and each section was cleaned as according to manu~acturer's speci~ication.

10 Specifically, Ditzler DX-330 - apply about 4 grams to Scott WypAllTM towel and apply to wax panel - wipe off with clean, dry Scott WypAll.
~ xample 1 - apply about 5 grams to Scott 15 WypAll towel and appl~ to waxed panel - wipe off with clean, dry WypAll towel.
ACME Aqua KlixTM - same as Example 1.
DuPont Prep Solvent II - apply about 5 grams with Scott WypAll towel - let stand about 2 minutes -20 remove with wet WypAll towel followed by dry WypAlltowel.
BASF - same as DuPont Prep Solvent II, except use two wet wipes.
.: .

'Fish EYes" Per 28 cm x 22 cm Panel Rain Dance Liquid Polish Example l26.5 27 DuPon~ 24.3 ~9.7 -~
BAS~ 26.7 29.7 ACME 25.0 37.3 Ditzler 4.7 11.7 The best cleaner is Ditæler DX-330, which is 35 a standard solvent cleaner and does not comply with VOC
standards. Example l compares favorably with the other low VOC cleaners, but accomplishes this cleaning in one step rather than two steps.

::

W092/18600 PCT/~S92/02760 jJ ,~1 - Cro.ss Hatch dhes.ion ~ . J cross hatch sections performed, one with a light scratch and one with a deep scratch in accordance with ASTM D3359. The performance evaluation 5 used the following criteria:

Good ~ No top paint removed ~rom paint directly covered - either scratch.
lO Fair - Some top coat removed from deep scratch only.
Poor - Some top coat paint removed from both scratch areas.
. Poor - total top coat paint removed over all taped area.

Cleaner Li~uld Polish Rain Dance Example 1 3 Good 3 Good; 1 Fair-Poor Ditzler 3 Good - 3 Good DuPont 3 Good; 1 Poor 1 Good; 1 Poor, 1 Very Poor 20 BASF 2 Good; 1 Poor 1 Poor; 2 Very Poor ~
ACME 2 Good; 1 Fair 2 Good; 1 Fair ::
~ '' Using this test, the composition of Example 1 performed as well or better than other low VOC prep solvents.
~ ::
_esh Paint Attack 24 hour old DuPont Centari Acrylic Enamel ~.
~ painted panels were used to test solvent attacX by prep : solvents.
Example 1 - no attack after 1 minute.
3M General Purpose Adhesive Cleaner - swells paint 5 10 seconds.
DuPont Prep Sol II 39295 - attacks, swells paint.
: ; 35 ACME Aqua Klix - very slight attack.

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WO92/18600 PCT/US92/~76~
j_ rl 5 rl ~ -- 18 BASF 905 - attacks, swells paintO

Stability, Particle Slze and Flash Poillt The stability of the experimental 5 microemulsions of the present invention was tested by sub~ecting samples to a minimum of three freeze-thaw cycles and to a minimum of one week at 50 C. Although some samples would separate into distinct phase, the transparent microemulsion could be restored with mild lO shaking.
Droplet particle size was determined by dynamic light scatterin~ using a Malvern Photon Correlation Spe~trometer~ -Flash point measurements were made according 15 to the Tag closed cup method in accordance with ~ :
ASTM D 56.
As will be apparent to those skilled in the :
art, var~ous other modifications can be carried out from the above disclosure without departing from the 20 spirit and scope of the invention.

Claims

CLAIMS:

1. A method of cleaning silicone wax, grease, grime, adhesives and the like from a hard surface in need of cleaning comprising i) applying to such surface an effective amount of a composition comprising an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9 (cal/cm3)1/2, sufficient surfactant to support a stable microemulsion, and water in an amount sufficient to provide a total VOC content of less than 200 grams/liter;
ii) allowing said composition to soften and otherwise ease removal of said silicone wax, grease, grime, and the like from the surface; and iii) wiping said composition and silicone wax, grease, grime, and the like from the surface with a dry wiping material.

2. The method of claim 1, wherein said solvent or solvent blend has a solubility parameter of between about 7.5 and 8.9.

3. The method of claim 1, wherein said solvent or solvent blend is at least 5% by weight polar or aromatic components.

4. The method of claim 1, wherein said microemulsion comprises:
a) an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9 (cal/cm3)1/2, b) sufficient nonionic surfactant or surfactant blend to maintain a microemulsion, and c) water in an amount sufficient to provide a total VOC content of less than 200 grams/liter.

5. The method of claim 4, wherein said microemulsion further comprises an additional surfactant selected from cationic, zwitterionic and anionic surfactants.

6. The method of claim 5, wherein said microemulsion further comprises a co-surfactant.

7. The method of claim 1, wherein said microemulsion comprises by weight:
a) 5-15% of an organic solvent or solvent blend having a solubility parameter of between about 6.9 and 8.9, b) 8-12% of a cationic or zwitterionic surfactant, c) 4-8% of a nonionic surfactant or surfactant blend having an HLB of between about 7.5 and 10, d) 1-5% of a co-surfactant, and e) 50-82% of water, such that the total VOC content of the microemulsion is less than 200 grams/liter.

8. A method of cleaning silicone wax, grease or grime according to claim 1, wherein said microemulsion comprises by weight:
5-8% aliphatic organic solvent, 1-3% co-surfactant, 3-5% amine oxide surfactant, 2-4% nonionic surfactant having an HLB
of between 7.5 and 10, and 80-89% deionized water to total 100%.

9. A method of cleaning adhesives according to claim 1, wherein said microemulsion comprises by weight:
12-15% organic solvent having at least 5%
aromatic or polar components, 1-4% co-surfactant, 8-12% amine oxide surfactant, 5-7% nonionic surfactant having an HLB
of between 7.5 and 10, and 62-74% deionized water to total 100%.

10. The method of claim 1, wherein said organic solvent or solvent blend is selected from the group consisting of odorless mineral spirits.

11. The method of claim 1, wherein said organic solvent or solvent blend is selected from the group consisting of aromatic mineral spirits, toluene, xylene and mixtures thereof.

12. The method of claim 7, wherein said cationic or zwitterionic surfactant is selected from the group consisting of alkylamine oxides.

13. The method of claim 7, wherein said cationic or zwitterionic surfactant is selected from the group consisting of cocadimethylamine oxide and lauryldimethamine oxide.

14. The method of claim 4, wherein said nonionic surfactant is selected from the group consisting of polyethoxylated linear, primary alcohols.

15. The method of claim 6, wherein said co-surfactant is selected from the group consisting of n-propanol, n-butanol, pentanol, propylene glycol, dipropylene glycol methyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, ethylene glycol butyl ether and dipropylene monoethyl ether.

16. The method of claim 15, wherein said co-surfactant is selected from the group consisting of n-propanol and dipropylene glycol methyl ether.

17. The method of claim 1, further comprising the step of previously removing the bulk of the residue to be removed by rubbing off said bulk with elastomeric disks.

18. The method of claim 1, wherein said microemulsion comprises by weight:
5-8% odorless mineral spirits, 1-3% n-propanol, 3-5% 30% active laurylamine oxide, 2-4% polyethoxylated linear primary alcohol, and 80-89% deionized water to total 100%.

19. The method of claim 1, wherein said microemulsion comprises by weight:

12-15% aromatic mineral spirits, 1 4% dipropylene glycol methyl ether, 8-12% 30% active laurylamine oxide, 5-7% polyethoxylated linear primary alcohol, and 62-74% deionized water to total 100%.

20. A microemulsion for cleaning silicone wax, grease or grime from hard surfaces comprising by weight:
5-8% aliphatic organic solvent, 1-3% co-surfactant, 3 5% amine oxide surfactant, 2-4% nonionic surfactant having an HLB
of between 7.5 and 10, and 80-89% deionized water to total 100%.

21. A microemuision for cleaning silicone wax, grease or grime from hard surfaces according to claim 14 comprising by weight:

5-8% odorless mineral spirits, 1-3% n-propanol, 3 5% 30% active laurylamine oxide, 2-4% polyethoxylated linear primary alcohol, and 80-89% deionized water to total 100%.

22. A microemulsion for cleaning adhesives from hard surfaces comprising by weight:
12-15% organic solvent having at least 5%
aromatic or polar components, 1-4% co-surfactant, 8-12% amine oxide surfactant, 5-7% nonionic surfactant having an HLB
of between 7.5 and 10, and 62-74% deionized water to total 100%.

23. A microemulsion for cleaning adhesives.
from hard surfaces according to claim 15 comprising by weight:
12-15% aromatic mineral spirits, 1-4% dipropylene glycol methyl ether, 8-12% 30% active laurylamine oxide, 5-7% polyethoxylated linear primary alcohol, and 62-74% deionized water to total 100%.