EP0052275B1 - Emulsion aqueuse de nettoyage - Google Patents

Emulsion aqueuse de nettoyage Download PDF

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Publication number
EP0052275B1
EP0052275B1 EP81109110A EP81109110A EP0052275B1 EP 0052275 B1 EP0052275 B1 EP 0052275B1 EP 81109110 A EP81109110 A EP 81109110A EP 81109110 A EP81109110 A EP 81109110A EP 0052275 B1 EP0052275 B1 EP 0052275B1
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EP
European Patent Office
Prior art keywords
weight
emulsion
percent
water
surfactant
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Expired
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EP81109110A
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German (de)
English (en)
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EP0052275A1 (fr
Inventor
Andrew Ferdinand Rutkiewic
James Paul White
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EIDP Inc
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EI Du Pont de Nemours and Co
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
    • C23G5/06—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using emulsions

Definitions

  • This invention relates to aqueous cleaing compositions and, more specifically, to aqueous compositions which possess great utility in connection with the cleaning of automotive finish surfaces. While the surface to be cleaned will ordinarily be composed of a polymeric material, e.g., the type of material used for primer, intermediate, or final coats, the novel composition of this invention will also clean bare metal surfaces. It is anticipated that the invention will be particularly valuable for use in automobile refinish shops, i.e., for cleaning an automobile or other vehicle prior to repair and/or repainting.
  • the present invention a water-in-oil emulsion which possesses excellent cleaning properties and is effective in removing both water-soluble and oil- or solvent-soluble materials.
  • the emulsion consists essentially of
  • the essence of the present invention lies in the discovery that a superior cleaning composition can be produced by emulsifying a major amount of water into a minor amount of organic solvent such that the water forms the internal, or dispersed, phase of the emulsion rather than the external, or continuous, phase.
  • the emulsion possesses the following advantageous characteristics:
  • the major component of the emulsion of the present invention is water.
  • the emulsion contains at least 70 percent by weight of water, preferably 72-78 percent.
  • the emulsion of this invention is a water-in-oil emulsion, wherein the water phase is dispersed as small globules in an oil, or solvent, phase. More specifically, 70-85 percent by weight of water is dispersed in 10-25 percent by weight of oil.
  • the emulsion contains 3-15 percent by weight of a blend of two or more nonionic surfactants, which serve to emulsify and stabilize.
  • the oil is a blend of aromatic organic solvents or aromatic and aliphatic organic solvents, selected on the basis of its solvency parameter.
  • Solvency parameters are well known in the art and are explained in considerable detail in an article by C. Hansen and A. Beerbower entitled “Solubility Parameters", Kirk-Othmer Ency. Chem. Tech., 2d Ed. 1971, Interscience, pp. 889-910, hereby incorporated by reference.
  • solvent blends possessing the requisite solvency parameter include, for example, 50:50 weight ratio blends of toluene and V.M. & P. naphtha, of xylol and certain aliphatic or aromatic hydrocarbons, and of aromatic controlled mineral spirits and certain aliphatic hydrocarbon solvents.
  • solvent blends possessing the requisite solvency parameter include, for example, 50:50 weight ratio blends of toluene and V.M. & P. naphtha, of xylol and certain aliphatic or aromatic hydrocarbons, and of aromatic controlled mineral spirits and certain aliphatic hydrocarbon solvents.
  • Other possibilities will be readily apparent to those having familiarity with solubility parameters and their application. It is anticipated that specific blends will be tailored to satisfy specific requirements; e.g., ease of emulsification may be desirable in order to satisfy time or equipment constraints, or higher flash points may become necessary in order to satisfy more stringent shipping regulations.
  • phase-volume ratio The ratio between the internal, or dispersed, phase of an emulsion and the external, or continuous, phase is referred to as the phase-volume ratio. If the phase-volume ratio is near 50:50, there will be no preference for the formation of either an oil-in-water or a water-in-oil emulsion.
  • the type of emulsion that is eventually formed will depend upon the choice of emulsifying agent, the chemical properties of the constituents, and the order of incorporation.
  • Surfactants serve to produce relatively stable mixtures of immiscible liquids by reducing interfacial tension. Unless the proper type, and quantity, of surfactant is incorporated into the emulsion of the present invention, the water droplets will have a strong tendency to reunite in order to decrease the free surface. The combination of nonionic surfactants employed in the present invention drastically lowers this strong interfacial tension, and thus, the tendency of the water droplets to flow together. The molecules of surfactant orient themselves at the interface of the water and the organic solvent blend and produce an interfacial film which protects the water droplets. The result is a water-in-oil emulsion of unusual and unexpected stability.
  • the emulsion of the present invention contains at least one hydrophobic nonionic surfactant having a hydrophile-lipophile balance (HLB) value less than 3.
  • This hydrophobic surfactant is used in conjuction with a second surfactant of hydrophilic character to produce a stable water-in-oil emulsion with exellent cleaning ability.
  • the preferred combination of hydrophobic and hydrophilic surfactants employed in the present invention imparts exceptional stability to the resultant emulsion, such that the emulsion can be subjected to fairly drastic temperature changes without losing its water-in-oil stability. Although phase separation, or even complete destabilization of the emulsion, may result from such temperature changes, homogenity is readily restored by shaking.
  • the hydrophilic surfactant must have an HLB value greater than 10, and must also be soluble in solvent blends having a solvency parameter with either a polar component value less than 9 or a hydrogen bonding component value less than 1. Solvent blends having such parameters are conventionally used in automotive coating compositions. Because the emulsion of the present invention has particular utility as a cleaner for automotive refinish purposes, it must in no way interfere with intercoat adhesion, i.e., the ability of the subsequently-applied coat of paint to adhere to the newly-cleaned surface. Upon evaporation of the solvent and water components of the emulsion, surfactant will be left behind on the vehicle surface. As the surface is painted, the hydrophobic portion of the surfactant blend will readily dissolve into the paint solvent.
  • the hydrophilic surfactant must also be soluble in this paint solvent, to preclude its remaining as a film on the surface and interfering with intercoat adhesion. It should be noted that, although the insertion of an additional washing step between the cleaning and painting steps would alleviate the problem of surfactant interference, such a step would be commercially impractical. At present, refinish practice requires no washing step, as the current solvent-based cleaners quickly volatilize. The necessity of adding a costly, labor-intensive extra step would undoubtedly be looked upon unfavorably by refinish shops.
  • Preferred hydrophobic surfactants belong to the class of poly(oxyethylene)-poly(oxypropylene) block copolymers having the general formula wherein a, b, and c are integers and the molecular weight of the poly(oxypropylene) content is between 2750 and 4000. These copolymers are available commercially from BASF Wyandotte Corporation under the trade name Pluronic°.
  • hydrophobic block copolymer surfactant has the chemical formula HO(CH 2 CH 2 O) 7 (CH 3 CHCH 2 O) 54 (CH 2 CH 2 O) 7 H. Its hydrophobic character is a function of the predominance of the hydrophobic poly(oxypropylene) base over the hydrophilic poly(oxyethylene) groups. The weight ratio of poly(oxypropylene) to poly(oxyethylene) in this surfactant is approximately 9:1.
  • hydrophilic surfactants are polyoxyethylated nonylphenols of the formula wherein n is a positive integer. These surfactants are available commercially from GAF Corporation under the trade name Igepel O CO.
  • One particularly preferred polyoxyethylated nonylphenol surfactant has the formula and comprises about 54 percent by weight of hydrophilic ethylene oxide.
  • An effective automotive cleaning fluid is produced by combining 70-85 percent by weight of water, 10-25 percent by weight of a blend of aromatic and aliphatic organic solvents having a solvency parameter with component values falling within the aforementioned ranges, 1.5-7.5 percent by weight of a hydrophobic nonionic surfactant having an HLB value less than 3, and 1.5-7.5 percent of a hydrophilic nonionic surfactant having both an HLB value greater than 10 and appropriate solubility.
  • One particularly recommended formulation consists essentially of 75-79 percent by weight of water, 15-17 percent by weight of a 50-50 weight ratio blend of toluene and V.M.&P.
  • naphtha 1.5-7.5 percent by weight of a poly(oxyethylene)-poly(oxypropylene) block copolymer hydrophobic surfactant, and 1.5-7.5 percent by weight of a polyoxyethylated nonylphenol hydrophilic surfactant.
  • Another particularly recommended formulation consists essentially of 75-79 percent by weight of water; 15-17 percent by weight of a 68:8:8:8 weight ratio blend of aromatic hydrocarbon, V.M.&P.
  • naphtha mineral spirits, heavy mineral spirits, and xylol; 1.5-7.5 percent by weight of a poly(oxyethylene)-poly(oxypropylene) block copolymer hydrophobic surfactant, and 1.5-7.5 percent by weight of a polyoxyethylated nonylphenol hydrophilic surfactant.
  • the latter formulation is characterized by a substantial higher flash point than is the 50:50 weight ratio blend of toluene and V.M.&P. naphtha, thus enabling compliance with shipping regulations requiring a "combustible" rather than "flammable” classification.
  • the stability of an emulsion is effected by many parameters.
  • process considerations e.g., the mixing equipment, the sequence in which the ingredients are added, the speed and duration of the process, and temperature changes, are of great importance.
  • an automotive cleaning emulsion will remain stable and retain its cleaning power under all conditions, including drastic temperature changes, will in no way interfere with the adhesion of substances, such as paint or wax, which are subsequently applied to the cleaned surface, and will easily remove all types of dirt and other unwanted substances. No one formulation will be optimal in all of these properties.
  • the composition of the emulsion of the present invention can be varied depending upon the particular purpose to which it is to be put and the properties required for such purpose.
  • a surfactant blend containing more hydrophobic surfactant and less hydrophilic surfactant will promote better intercoat adhesion, for example, whereas a blend containing more hydrophilic surfactant will yield improved stability.
  • both the aqueous phase and the oil phase are prepared in advance.
  • the oil phase is prepared by dissolving the hydrophobic surfactant in the solvent blend by simple agitation, and the hydrophilic surfactant is similarly introduced into the water to form the aqueous phase.
  • the time required for emulsification is dependent upon the mixing apparatus as well as the specific characteristics desired of the resultant cleaner.
  • a common type of mixing operation and one adequately suited for use in the present invention, involves one or more propellers mounted on a common shaft in a mixing tank. Propeller agitation is satisfactory for low and medium viscosity emulsions, and it is anticipated that the emulsion of the present invention will be most useful if of low enough viscosity to be a pourable liquid.
  • a shorter mix time and a lower mixing speed yield emulsions of lower viscosity, while higher viscosity emulsions are the result of longer mix times at higher speeds.
  • Other conventional mixing methods may also be employed.
  • Toluene (63 parts), V.M.&P. naphtha (63 parts), and a poly(oxyethylene)-poly(oxypropylene)block copolymer having the formula HO(CH2CH,0)7(CH3CHCH20)14(CH2CHO),H (24 parts) are combined and mixed until blended, about 5 minutes.
  • a polyoxyethylated nonylphenol having the formula (36 parts) is added to water (603 parts) and the mixture is stirred until the copolymer is thoroughly dissolved, about 20 minutes.
  • the aqueous portion is added gradually, with mixing, to the solvent portion. This addition is performed in about 25 minutes, following which the resultant emulsion is mixed for an additional 5 to 10 minutes.
  • the emulsion so prepared has a viscosity of about 14 poise, as measured with a Brookfield LVT #3 spindle at 12 r.p.m., and is a pourable fluid.
  • the viscosity of the emulsion is dependent upon many factors, including the mix time, the mixing speed, and the type of mix blade. By varying one or more of these factors, a person or ordinary skill in the art can arrive at the particular viscosity desired for a specific use or circumstance.
  • the emulsion is applied to a dry cloth and tested for cleaning power using standard procedures.
  • a waxed automotive panel is rubbed with the emulsion-containing cloth and allowed to dry.
  • the panel is then swabbed with a cotton swab which has been soaked with hexylene glycol.
  • the surface tension of a waxed finish is about 26 dynes/cm, whereas the surface tension of an unwaxed finish is about 35 dynes/cm.
  • Hexylene glycol, having a surface tension of about 29 dynes/cm is a usefuj indicator of wax removal, as it will wet a wax-free surface but will not wet a waxed surface. This test reveals that all the wax has been removed from the panel by the cleaning emulsion, because the hexylene glycol stays in contact with the panel with no visible crawling or creeping.
  • an automotive panel is coated with stripes of road tar. Holes are punched in strips of masking tape and placed over the tar stripes. A'few drops of emulsion are placed in each hole, allowed to stand for several minutes, and dabbed off with paper towels. No tar remains beneath the holes. Panels containing various other substances commonly encountered on automotive panels, e.g., mud, sanding dust, bird and insect excrement, and tree sap, are cleaned with the emulsion. In each instance, the substance is totally removed.
  • Freeze/thaw and oven stability tests are conducted to determine the emulsion's capacity for remaining stable upon undergoing severe temperature change. Samples of the emulsion are placed in an oven and kept at 120°F for eleven days. When removed on twelfth day, the emulsion has the same appearance and cleaning ability as another sample which has undergone no temperature change. Next, samples of emulsion are frozen, thawed, frozen a second time, and again thawed. Although some separation occurs, shaking reconstitutes the water-in-oil emulsion, and its cleaning power is unhampered.
  • intercoat adhesion tape tests are conducted to ascertain that use of the cleaning emulsion will not interfere with the adhesive capabilities of the cleaned surface.
  • An automotive panel is first cleaned with the emulsion and allowed to dry. The panel is then sprayed with conventional automotive paint and air dried. There is no additional washing step between the cleaning of the panel and its painting. The dried panel is then scored, with "X"-shaped cuts extending completely through the newly-applied topcoat. Strips of masking tape are affixed to the panel, over the cuts, and are pulled. The painted surface remains virtually intact, indicating that use of the emulsion will not interfere with intercoat adhesion.
  • the pourable consistency of the cleaning emulsion is conducive to easy application by conventional techniques.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Detergent Compositions (AREA)

Claims (5)

1. Composition de nettoyage formée d'une émulsion eau-dans-huile comprenant essentiellement:
(a) une phase dipsersée de 70-85% en poids d'eau, relativement au poids de l'émulsion;
(b) une phase continue, de 10 à 25% en poids, par rapport au poids de l'émulsion, d'huile cette huile étant un mélange de solvants organiques aromatiques ou de solvants organiques aromatiques et aliphatiques ayant un paramétre de solubilisation avec une valeur de constituant de dispersion de 7,70 à 8,80, une valeur de constituant polaire de 0 à 0,70 et une valeur de constituant de liaison hydrogène de 0,005 à 1,42; et
(c) 1,5-7,5% en poids, relativement au poids de l'émulsion, d'au moins un agent tensio-actif non ionique hydrophobe ayant une valeur EHL inférieure à 3; et
(d) 1,5­7,5% en poids, relativement au poids de l'emulsion, d'au moins un agent tensio-actif non ionique hydrophile ayant une valeur EHL supérieure à 10 et soluble dans des mélanges de solvants ayant un paramètre de solubilisation avec une valeur de constituant polaire inférieur à 0,9 ou une valeur de constituant de liaison hydrogène inférieure à 1.
2. Composition selon la revendication 1, dans laquelle l'agent tensio-actif hydrophobe est une copolymère séquencé poly(oxyéthylène)-poly(oxypropylène) de la formule:
Figure imgb0009
dans laquelle a, b et c sont des nombres entiers positifs et le poids moléculaire de la teneur en poly (oxypropylène) est de 2750 à 4000.
3. Composition selon la revendication 2, dans laquelle l'agent tensio-actif hydrophile est un nonyl- phénol polyoxyéthylé de la formule:
Figure imgb0010
dans laquelle n est un nombre entier positif.
4. Composition selon la revendication 1, 2 ou 3, qui est formée essentiellement de 75-79% en poids d'eau, 15-17% en poids de mélange de solvants, 1,5­7,5% en poids d'agent tensio-actif hydrophobe, et 1,5­7,5% en poids d'agent tensio-actif hydrophile.
5. Compostion selon la revendication 4, dans laquelle le mélange de solvants est essentiellement formé de toluène et de naphte V.M. & P. en un rapport en poids de 50:50.
EP81109110A 1980-11-19 1981-10-28 Emulsion aqueuse de nettoyage Expired EP0052275B1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US20842180A 1980-11-19 1980-11-19
US208421 1980-11-19
US25257381A 1981-04-09 1981-04-09
US252573 1981-04-09

Publications (2)

Publication Number Publication Date
EP0052275A1 EP0052275A1 (fr) 1982-05-26
EP0052275B1 true EP0052275B1 (fr) 1985-11-06

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EP81109110A Expired EP0052275B1 (fr) 1980-11-19 1981-10-28 Emulsion aqueuse de nettoyage

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EP (1) EP0052275B1 (fr)
BR (1) BR8107396A (fr)
CA (1) CA1170950A (fr)
DE (1) DE3172845D1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06506496A (ja) * 1991-04-10 1994-07-21 ミネソタ　マイニング　アンド　マニュファクチャリング　カンパニー 低揮発性有機化合物の洗浄組成物及び方法
GB2316415B (en) * 1995-12-28 1998-06-03 Eco Solutions Limited Aqueous composition for plasticising paint prior to strip
NZ324776A (en) 1995-12-28 1998-12-23 Eco Solutions Ltd Aqueous composition for plasticising paint prior to stripping
NZ507650A (en) 1998-03-19 2003-12-19 Eco Solutions Ltd Aqueous composition for removing coatings
AU2006207974B2 (en) * 2005-01-27 2011-03-03 Lubrizol Advanced Materials, Inc. Personal care composition containing hydrophobically modified polymers

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2214974C3 (de) * 1972-03-28 1979-05-03 Metallgesellschaft Ag, 6000 Frankfurt Verfahren zur Spritzreinigung von Metalloberflächen vor der Phosphatierung
US3969552A (en) * 1974-05-08 1976-07-13 Loctite Corporation Process for impregnating porous articles
DE2706654A1 (de) * 1976-02-23 1977-08-25 F S C Ind Inc Zusammensetzungen und verfahren zum entfernen von oelschichten
JPS6031239B2 (ja) * 1977-12-23 1985-07-20 日本ペイント株式会社 脱脂洗浄剤

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Emulsifiers and Emulsifying Techniques", J.C. Johnson, Noyes Data Corporation (USA) 1979 *
Kirk-Ottner: Encyclopaedia of Chemical Technology Third Edition, volume 21, pages 378, 382 *

Also Published As

Publication number Publication date
BR8107396A (pt) 1983-04-12
CA1170950A (fr) 1984-07-17
DE3172845D1 (en) 1985-12-12
EP0052275A1 (fr) 1982-05-26

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