KR19990036227A - Improvements for Hard Surface Cleaning Compositions - Google Patents

Abstract

The present invention relates to the use of a water-soluble anionic polymer as an agent for preventing the propagation of surface cracks in a plastic cleaning composition comprising a nonionic surfactant, comprising (a) 1 to 30% by weight of a nonionic surfactant and (b) ) A plastic comprising 0.005 to 3 weight percent of a water soluble anionic polymer having an average molecular weight of less than 1,000,000, the surface being treated with a cleaning composition having a pH of 2 to 10 with a ratio of polymer and nonionic surfactant of 0.1: 1 or less. Provided are methods for cleaning surfaces.

Description

Improvements for Hard Surface Cleaning Compositions

Hard surface cleaning compositions generally comprise one or more nonionic surfactants as cleaning agents involved in removing contaminants from the surface.

A wide range of nonionic surfactants are known and used in cleaning compositions. For example, these surfactants include alkoxylated alcohols, which are typically described as compounds produced by condensation of hydrophilic alkylene oxide groups with organic hydrophobic compounds which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical condensed with any particular hydrophobic group can be easily adjusted to produce a water soluble compound having a desirable degree of balance between hydrophilic and hydrophobic elements. Specific examples include condensation products of aliphatic alcohols having 8 to 22 carbon atoms of straight or branched chain structure with ethylene oxide, for example, coconut oil ethylene oxide condensates having 2 to 15 moles of ethylene oxide per mole of coconut alcohol, and The alkyl group includes condensates of alkylphenols containing 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol.

It is known to incorporate these components into compositions based on nonionic surfactants for the purpose of depositing these components on the surface to provide a protective layer against contamination in a one step cleaning operation. Applicant's International Patent Application WO 94/26858 discloses a nonionic surfactant in which certain anionic polymers improve initial cleaning and prevent re-deposition of contaminants on hard surfaces cleaned with a composition comprising these polymers. And how it can be used together.

Cleaning compositions based on nonionics may also contain fragrances for the user's acclaim and odor prevention and solvents for cleaning aids. It is believed that nonionic surfactants, particularly when present in admixture with a solvent, promote surface damage to the stressed plastic material in use or during manufacture. Such surface damage can lead to gloss loss and / or structural defects in the material. The present invention is directed to overcoming the problem of surface damage due to compositions containing nonionic surfactants, both at least partially in the presence or absence of a solvent.

The present invention relates to a general purpose, ie a liquid cleaning composition of a hard surface comprising a nonionic surfactant and a polymer component. In use, these compositions can be used in contact with plastic surfaces such as surfaces of bathtubs, work benches, and the like.

The inventors of the present invention have found that the anionic polymers have a protective effect against surface damage on the plastic material which occurs in the presence of nonionic surfactants.

Accordingly, the present invention provides the use of a water soluble anionic polymer as an agent for preventing the propagation of surface cracks in a plastic cleaning composition comprising a nonionic surfactant.

Another aspect of the invention

(a) 1 to 30 weight percent of the nonionic surfactant, and

(b) treating the surface with a cleaning composition having a pH of 2 to 10 comprising 0.005 to 3 weight percent of a water soluble anionic polymer having an average molecular weight of less than 1,000,000 and a ratio of polymer to nonionic surfactant of 0.1: 1 or less. It relates to a method for cleaning a plastic surface.

It is believed that the advantages of the compositions and methods of the present invention are reduced surface damage caused by structural defects or gloss defects. In addition, the compositions of the present invention allow the cleaning effect of the nonionic surfactant to mitigate the surface damaging effect, i.e., a composition that is well cleaned is already aggressive to the surface and a composition that is poorly cleaned is less aggressive. The compositions of the present invention are much less aggressive and effective cleaners for surfaces.

While not wishing to be bound by any particular theory, it is believed that damage to the plastic surface requires the presence of a plasticizer for the weakening of the plastic and plastic materials that are stressed in use or during manufacture so that cracks formed by the stress can propagate. . If the cracks are long and / or wide, the material is structurally weakened and the presence of the cracks causes a loss of surface finish. The presence of the polymer is believed to physically block the surface to retard the activity of the surfactant as a plasticizer or to reduce access to the cracked portion.

Various preferred and essential features of the invention are described in more detail below.

polymer

Water soluble polymers are an essential component of the composition according to the invention.

Surprisingly, the most preferred polymers in embodiments of the invention are those readily available on the market. These are polymers of acrylic acid or methacrylic acid or maleic anhydride, or copolymers with one or more of them, or copolymers with one or more of them with other monomers.

Particularly suitable polymers include polyacrylic acid, polymaleic anhydride, and copolymers thereof with ethylene, styrene or methyl vinyl ethers.

Most preferred polymers are maleic anhydride copolymers, preferably maleic anhydride copolymers formed of styrene, acrylic acid, methyl vinyl ether or ethylene.

Preferably, the molecular weight of the polymer is at least 5,000, more preferably at least 50,000 and most preferably greater than 100,000.

Typically, the surfactant based cleaning composition comprises at least 0.01% by weight of polymer, based on the product. Unexpectedly, it has been found that the positive benefits to the presence of polymers can be seen even in the presence of very small amounts of polymers and surfactants. This low threshold characteristic is particularly advantageous in the application of the present invention where significant dilution is expected.

Preferably, the amount of polymer is from 0.05 to 5.0% by weight, in which the recontamination prevention benefit is of particular importance. More preferably, 0.2 to 2.0% by weight of polymer is present. The inventors of the present invention have determined that a high content of polymer does not provide significant cleaning benefits due to conventional dilution factors while increasing the cost of the composition. Higher polymers are believed to increase the viscosity of the product and interfere with the wettability of the product and the penetration of contamination. However, for concentrated products diluted prior to use, the initial polymer content can be as high as 5% by weight.

In the description of the invention, the anionic polymer is a polymer that delivers negative charge or a similar polymer in protonated form.

As mentioned above, the molecular weight of the polymer is preferably less than 1,000,000 daltons. Increasing the molecular weight is believed to reduce the cleaning benefit of the polymer.

Surfactants

It is essential that the composition according to the invention comprises at least one nonionic surfactant. The composition according to the invention comprises a detergent active substance which may be selected from nonionic detergent active substances. Suitable nonionic detergent active compounds can be broadly described as compounds produced by the condensation of organic hydrophobic compounds which may be originally aliphatic or alkyl aromatic with hydrophilic alkylene oxide groups.

The length of the hydrophilic or polyalkylene radical condensed with any particular hydrophobic group can be easily adjusted to produce a water soluble compound having a desirable degree of balance between hydrophilic and hydrophobic elements.

Specific examples include condensation products of aliphatic alcohols having 8 to 22 carbon atoms of straight or branched chain structure with 2 to 15 moles of ethylene oxide. Examples of such materials are coconut oil ethylene oxide condensates having 2 to 15 moles of ethylene oxide per mole of coconut alcohol, alkylphenols having 6 to 12 carbon atoms in the alkyl group and 5 to 25 ethylene oxide per mole of alkylphenol. containing a condensation product, a polyoxyethylene radical 40 to 80 weight% of the mole and having a molecular weight of 5,000 to 11,000, ethylene diamine oxide and condensates of propylene and ethylene oxide reaction product of the formula R ₃ NO (wherein one of R The groups are alkyl groups having 8 to 18 carbon atoms, the other groups are each methyl, ethyl or hydroxy-ethyl groups, for example tertiary amine oxides, for example dimethyldodecylamine oxide, in which R ₁ PO R groups are alkyl groups having 10 to 18 carbon atoms, and other groups are each alkyl or hydroxyalkyl groups having 1 to 3 carbon atoms, for example dimethyldodecyl phos. Fin oxides, dialkyl sulfoxides of the formula R ₂ SO, wherein one R group is an alkyl group having 10 to 18 carbon atoms and the other group is methyl or ethyl, for example methyltetradecyl sulfoxide, fatty acid alkylol Alkylene oxide condensates of amides, fatty acid alkylolamides and alkyl mercaptans.

Preferred nonionic surfactants are condensation products of alcohols having 9 to 15 carbon atoms with 3 to 10 moles of ethylene oxide.

The amount of nonionic detergent active material used in the composition of the present invention is generally 1 to 30% by weight, preferably 5 to 20% by weight and most preferably 12 to 20% by weight. The amount of active material of about 15% is particularly preferred if the cleaning performance hardly increases at high contents in suitable applications, although high contents can be used in products intended to be significantly diluted before use.

Optionally, anionic surfactants may be present in relatively small proportions.

Suitable anionic detergent active compounds are water soluble salts of organic sulfur reaction products having alkyl radicals containing 8 to 22 carbon atoms in the molecular structure, and radicals selected from sulfonic acid or sulfuric acid ester radicals and mixtures thereof.

Examples of anionic detergents are sodium and potassium alcohol sulfates, especially sodium and potassium alcohol sulfates obtained by sulfated higher alcohols produced by reduction of glycerides of resins or coconut oil, sodium containing from 9 to 15 carbon atoms in alkyl groups. And potassium alkyl benzene sulfonates, sodium and potassium secondary alkanesulfonates, sodium alkyl glyceryl ether sulfates, especially those ethers of higher alcohols derived from resins and coconut oil, sodium coconut oil fatty acid monoglyceride sulfates, higher fatty alcohols 1 Sodium and potassium salts of the sulfuric esters of the reaction product of the molar and ethylene oxide 1 to 6 moles, sodium and potassium salts of alkyl phenol ethylene oxide ether sulfates having 1 to 8 units of ethylene oxide molecules, where the alkyl radicals are carbon atoms Containing 4 to 14), esterified with isethionic acid And the reaction product of fatty acids neutralized with sodium hydroxide include (where, for example, fatty acids derived from coconut flow path search), and mixtures thereof.

Preferred water-soluble synthetic nonionic detergent active compounds are ammonium and substituted ammonium (such as mono, di and triethanolamine), alkali metals (such as sodium and potassium) and higher alkaline benzene sulfonates (such as sodium and potassium) and alkaline earth metals (such as calcium and magnesium) Mixtures of olefinsulfonates of salts with higher alkyl sulfates, and higher fatty acid monoglyceride sulfates.

Most preferred anionic detergent active compounds are higher alkyl aromatic sulfonates, such as higher alkyl benzene sulfonates containing 6 to 20 carbon atoms in the alkyl group, straight or branched chain, specific examples of which are higher alkyl benzene sulfonates or Sodium salt of higher alkyl toluene, xylene or phenol sulfonate, alkyl naphthalene sulfonate, ammonium diamyl naphthalene sulfonate and sodium dinonyl naphthalene sulfonate.

The amount of synthetic anionic detergent active material used in the detergent composition of the present invention is less than 33% by weight (based on total active material).

Alternatively, it is also possible to include amphoteric, cationic or zwitterionic detergent active materials in the compositions according to the invention.

Suitable amphoteric detergent active compounds which may optionally be selected are derivatives of aliphatic secondary and tertiary amines containing aliphatic radicals substituted by alkyl groups having 8 to 18 carbon atoms and anionic water soluble groups, for example sodium 3-dode Silamino-propionate, sodium 3-dodecylaminopropane sulfonate and sodium N-2-hydroxydodecyl-N-methyltaurate.

Suitable amphoteric detergent active compounds which may optionally be selected are quaternary ammonium salts having aliphatic radicals having 8 to 18 carbon atoms, for example cetyltrimethyl ammonium bromide.

Suitable zwitterionic detergent active compounds which may be optionally selected are derivatives of aliphatic quaternary ammonium, sulfonium and phosphonium compounds having aliphatic radicals substituted by aliphatic radicals with 8 to 18 carbon atoms and anionic water-soluble groups, eg For example 3- (N, N-dimethyl-N-hexadecylammonium) propane-1-sulfonate betaine, 3- (dodecylmethyl sulfonium) propane-1-sulfonate betaine and 3- (cetylmethylforce Phonium) ethane sulfonate betaine.

Another example of a suitable detergent active compound is the textbook known by Schwartz and Perry [Surface Active Agents, Volume I] and the textbook by Schwartz, Perry and Berch [Surface Active Agents and Detergents, Volume II] is a compound usually used as the surface active agent.

The total amount of detergent active compound used in the detergent composition of the present invention is generally 1.5 to 30% by weight, preferably 2 to 20% by weight, most preferably 5 to 20% by weight.

menstruum

The compositions of the present invention have the formula R ₁ -O- (EO) _m- (PO) _n -R ₂ , wherein R ₁ and R ₂ are independently C 2-6 alkyl or H, but not both hydrogen, m and n Is independently 0 to 5) of 2% by weight or less of the solvent. It is believed that the use of polymers as in the compositions of the present invention can counteract the toxic effects of all solvents present.

More preferably, up to 2% by weight of a solvent selected from the group comprising di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether and mixtures thereof are present. .

Advantageously, it is effective that no solvent other than water is present.

Trace ingredients

The compositions according to the invention may contain other ingredients which aid their cleaning performance.

For example, the composition may include nitrilotriacetate, polycarboxylate, citrate, dicarboxylic acid, water soluble phosphate, in particular a mixture of polyphosphate, ortho- and pyrophosphate, zeolites and mixtures thereof, as defined herein. It may contain detergent extenders other than special water soluble salts. Such extenders may also function as abrasives when present in an amount in excess of their solubility in water as described herein. Generally, when an extender other than a special water soluble salt is used, it is preferably 0.1 to 25% by weight based on the weight of the composition.

Metal ion sequestrants such as ethylenediaminetetraacetate, amino-polyphosphonates (DEQUEST®) and phosphate, and a wide variety of other multifunctional organic acids and salts may also optionally be used.

Any further component for the composition according to the invention is a suds control material which can be used in the composition according to the invention which has a tendency to cause excessive lather when in use. One example of a suds control substance is soap. Soaps are salts of fatty acids and include alkali metal soaps such as the sodium, potassium, ammonium and alkanol ammonium salts of higher fatty acids containing from about 8 to about 24 carbon atoms and preferably from about 10 to about 20 carbon atoms. . Particularly useful are the mono-, di- and triethanolamine salts of fatty acid mixtures derived from sodium and potassium and coconut and peanut oils. The amount of soap when used may be at least 0.005% by weight, preferably 0.5 to 2% by weight, based on the weight of the composition. Another example of a lather control material is an organic solvent, hydrophobic silica and a silicone oil or hydrocarbon.

The composition according to the invention also contains, in addition to the ingredients already mentioned, perfumes which increase the solubility of pH adjusters, colorants, optical bleaches, antifouling agents, detergent enzymes, compatible bleaches, gel modifiers, freeze-thaw stabilizers, fungicides, preservatives, detergents. And various other optional ingredients such as opaques.

It is preferred that the composition of the present invention is essentially free of abrasive particles. Experiments have shown that although abrasives in themselves provide independent cleaning benefits, the presence of the abrasive reduces cleaning benefits due to the polymer. Abrasives, surfactants, and polymers are believed to form complexes that reduce the effective concentration of surfactant at the surface being cleaned.

As mentioned above, the pH of the composition according to the invention is acidic or neutral. The inventors of the present invention have found that the improved cleaning and / or antifouling benefits are obtained at these pHs. Preferred pH of the product is pH 3 to 7, more preferably pH 3 to 6 and particularly preferably pH 4 to 6 to provide an equilibrium between the risk of acid composition and the benefits of acid to remove limestone.

Particularly preferred compositions according to the invention are

(a) 5 to 20% by weight of an alkoxylated alcohol which is a nonionic surfactant,

(b) less than 3% by weight of anionic surfactant,

(c) a water-soluble anionic polymer having an average molecular weight of less than 1,000,000, which is a polymer of at least one of acrylic acid, methacrylic acid or maleic anhydride and at least one of acrylic acid, methacrylic acid, maleic anhydride, ethylene, styrene and methyl vinyl ether 0.2 to 2 weight percent, and

(d) pH 3 to 2, comprising up to 2% of a solvent selected from the group comprising di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether and mixtures thereof It is a flowable aqueous liquid with six.

The invention will be further understood by the following examples.

The following examples were obtained using a method analogous to the industry standard method using a contact time of 24 hours. Shorter (1 hour) contact times were used to distinguish samples well.

A strip of transparent Perspex (TM) 3 mm thick, 127 mm long and 12.7 mm wide was cut from the sheet with a band saw. Each strip was placed in a bending jig under 1.75% flexural strain (corresponding to 40 mega Pascals). While still in the flexure, the strip was allowed to contact the test solution of the nonionic surfactant with the additives described below for 1 hour.

The liquid under test was placed in a clear 12 cm glass Petri dish or in another suitable recessed container and the flexor was rotated over them. The flexor was stably supported above a workbench height of 1.5 to 2 cm in such a way that the vertices of the flexed plastic were in good contact with the test medium. The contact time for 1.75% of the flexural strainers (116 mm apart between the grooves in the flexors) was 1 hour at 25 ° C.

After 1 hour, the strips were rinsed with demineralized water, removed from the flexure and dried by careful wiping to avoid scratching. Care should be taken at this stage as the windshield is so sharp that if you move your finger along its edge it can be thinly cut and the bend may spring up. The strip was placed on an overhead projector for inspection and cracks were found in the displayed image. The degree of cracking was assessed by the evaluator panel with a score of 0 to 20 to indicate the most intact to the most intact.

The damage was evaluated by the following 20 points.

0 = no damage at all.

1 = very slightly damaged to the naked eye.

2 = slightly damaged.

3 = Some undamaged surface at the site of contact, but significantly damaged.

4 = Some small and hard cracks exist throughout the strip width.

5 = There is a stress crack throughout the width that is clearly identifiable.

Scores from 6 to 20 are evaluated by tapering the four strips together (eg, on overhead projectors) and evaluating light transmission for a predetermined standard setting. An evaluator panel was composed and the results were averaged.

In the experiments described above, the solvent used was Butyl Digol (TM, ex BDH) comprising predominantly di-ethylene glycol mono-n-butyl ether. If present, the solvent is present in the composition in an amount of 5% by weight.

Surfactants used are as follows.

Dobanol 91/8: C8-11 alcohol condensed with 8 moles of ethylene oxide.

Dobanol 23 / 6.5: C12-13 alcohol condensed with 6.5 moles of ethylene oxide.

Dobanol 91/5: C9-11 alcohol condensed with 5 moles of ethylene oxide.

Rial 111 / 5.5: C10-11 alcohol condensed with 5.5 moles of ethylene oxide.

Dobanol is a trademark of Shell. Rial is a trademark of Enichem. The surfactant was present in the product in an amount of 10% by weight.

The perfume used was Opalina (TM, manufactured by Firmenich). The polymer used was Versiocol E11 (TM, manufactured by Allied Colloids). If present, the polymer was present in an amount of 0.5% by weight. The polymer containing the sample also contained 2% by weight nitric acid. The composition was made up to 100% by weight with water. All percentages are expressed in weight percent based on the weight of the product.

The results obtained are shown in Table 1 below, and each composition (base, solvent added and polymer added) was prepared in the presence or absence of a polymer and in the presence of 1 to 4 different surfactants. In column (A), for example, four samples treated with a strip included 10% by weight of surfactant (as shown), 0.5% by weight of polymer and 5% by weight of solvent. The results shown in the columns (B), (D) and (F) are the results of the comparative example.

(A) Polymer (B) Polymer member (C) polymer (D) Polymeric member (E) Polymer (F) Polymer member Surfactant (10%) 5% solvent 5% solvent 0.5% perfume 0.5% perfume Additive Additive Dobanol 91/8 7.5 15 0.5 5 One 5 Tobanol 23 / 6.5 7.5 18.25 One 2 0 0 Dobanol 91/5 9.5 17 2.5 10 One 3.75 Rial 111 / 5.5 2.5 20 2.5 7.5 1.25 7.5

From Table 1 it can be seen that the surface damage was significantly reduced in the presence of the polymer both in the presence of the solvent (compare A and B columns) and in the absence (compare C and D and E and F columns). It can be seen that the degree of surface damage in the absence of solvent and in the presence of polymers (columns C and E) occurred less than in experiments adjusted to nonionic surfactants only (columns D and F).

Examples of preferred compositions are shown in column C. These included nonionic surfactants, perfumes and polymers, and no solvents.

The results of some further experiments are shown in Table 2 below. In the experiments shown in Table 2, the results were obtained by the method given with addition of 2% versicol E11 and 2% nitric acid (B column) and no addition (column A). The materials used in Table 2 were as described above, the solvent was butyl digol and the perfume was opalina.

Surfactants additive Damage Score: A Damage Score: B Dobanol 91-5 none 4 One Dobanol 91-5 5% Digol 17 9.5 Dobanol 91-5 5% Digol + 0.5% Perfume 19.5 16.25 Dobanol 91-5 0.5% perfume 10 2.5 Dobanol 91-8 none 5.5 One Dobanol 91-8 5% Digol 15 7.5 Dobanol 91-8 5% Digol + 0.5% Perfume 15 8 Dobanol 91-8 0.5% perfume 5 0.5 Tobanol 23 / 6.5 none 0 0 Tobanol 23 / 6.5 5% Digol 18.25 7.5 Tobanol 23 / 6.5 5% Digol + 0.5% Perfume 16.5 19.5 Tobanol 23 / 6.5 0.5% perfume 2 One Rial 111 / 6.5 none 7.5 1.25 Rial 111 / 5.5 5% Digol 20 2.5 Rial 111 / 5.5 5% Digol + 0.5% Perfume 19.25 13.0 Rial 111 / 5.5 0.5% perfume 7.5 2.5

From the results in Table 2, it can be seen that almost all of the systems tested showed that the surface damage was significantly reduced when the polymer was added to the composition. Surface damage appears to be particularly bad in the presence of both perfumes and solvents.

Claims (8)

Use of a water soluble anionic polymer as an agent for preventing the propagation of surface cracks in a plastic cleaning composition comprising a nonionic surfactant. The plastic of claim 1 wherein solvents selected from the group consisting essentially of di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether, and mixtures thereof are not necessarily present. Use of a water soluble anionic polymer in cleaning compositions. The use of water-soluble anionic polymers according to claim 1, wherein the water-soluble anionic polymer is acrylic acid or methacrylic acid or maleic anhydride, or a copolymer with one or more of these, or a copolymer of one or more of them with other monomers. The composition of claim 1 wherein the composition is (a) 5 to 20% by weight of 3 to 10 molar equivalents of alkoxylated alcohol having 9 to 15 carbon atoms as a nonionic surfactant, (b) less than 3% by weight of anionic surfactant, (c) a water-soluble anionic polymer having an average molecular weight of less than 1,000,000 as a polymer of at least one of acrylic acid, methacrylic acid or maleic anhydride with at least one of acrylic acid, methacrylic acid, maleic anhydride, ethylene, styrene and methyl vinyl ether 0.2 to 2 weight percent of the polymer, and (d) water-soluble anionic polymers comprising up to 2% of a solvent selected from the group comprising di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether and mixtures thereof Use of (a) 1 to 30 weight percent of the nonionic surfactant, and (b) treating the surface with a cleaning composition of pH 2 to 10 comprising 0.005 to 5% by weight of a water soluble anionic polymer having an average molecular weight of less than 1,000,000, wherein the ratio of polymer to nonionic surfactant is 0.1: 1 or less. The cleaning method of the plastic surface to make. 6. The method of claim 5 wherein the anionic polymer comprises acrylic acid or methacrylic acid or maleic anhydride, or a copolymer with one or more of these, or a copolymer of one or more of them with other monomers. 6. The process of claim 5 wherein the nonionic surfactant is 3 to 10 molar equivalents of alkoxylated alcohols having 9 to 15 carbon atoms. (a) 5 to 20% by weight of 3 to 10 molar equivalents of alkoxylated alcohol having 9 to 15 carbon atoms as a nonionic surfactant, (b) less than 3% by weight of anionic surfactant, (c) a water-soluble anionic polymer having an average molecular weight of less than 1,000,000 as a polymer of at least one of acrylic acid, methacrylic acid or maleic anhydride with at least one of acrylic acid, methacrylic acid, maleic anhydride, ethylene, styrene and methyl vinyl ether 0.2 to 2 weight percent of the polymer, and (d) a surface with a cleaning composition comprising up to 2% of a solvent selected from the group comprising di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether, and mixtures thereof Method of cleaning the plastic surface comprising the step of treating.