Abstract:
Liquid hard-surface cleaning compositions are disclosed which have a viscosity above 30 cps, show excellent cleaning on both kitchen and bathroom soils, and excellent shine performance. 
     These compositions are substantially free of hydrotropes, and contain a narrowly-defined binary solvent system constituted by Butyl Carbitol as one of the solvents and Butoxy Propoxy Propanol or Hexyl Carbitol as the other solvent.

Description:
TECHNICAL FIELD 
     The present invention relates to liquid viscous hard-surface cleaning compositions containing a binary, glycol ether solvent system which have a viscosity above 30 cps, show excellent cleaning on both kitchen and bathroom soils, and excellent shine performance. 
     These compositions are substantially free of hydrotropes, and contain a narrowly-defined binary solvent system constituted of Butyl Carbitol as one of the solvents and butoxy propoxy propanol or Hexyl Carbitol as the other solvents. 
     BACKGROUND 
     It is well-known to formulate hard-surface cleaning compositions containing solvents. 
     In particular, compositions containing a binary solvent system constituted of terpenes and polar solvents such as benzyl alcohol and Butyl Carbitol have been disclosed in European Patent Nos. 0 040 882 and 0 080 749. 
     There is a need for hard-surface cleaners containing organic solvents, which are substantially free of hydrotropes, since hydrotropes such as cumene sulfonate can be deterimental to performance, especially shine. 
     There is also a need for liquid hard-surface cleaners which are more viscous than current similar products, i.e. which have a viscosity above 30 cps. Indeed, a product with such a viscosity, will show a better pouring control, will avoid product loss by penetration into e.g. the sponge used to apply it on the surface, and will be more efficient for use on inclined surfaces. Viscous products can be formulated using thickening agents typically used in commercial products. The rheology of such compositions is generally less desirable than that of the current invention. Thickening agents can also be detrimental to product performance. 
     It has now been found that liquid hard-surface cleaning compositions can be formulated, which are substantially free of hydrotrope, are substantially viscous and show remarkable cleaning efficiency on both kitchen and bathroom soils, and shine performance. Such compositions contain a specific binary solvent system. 
     EP-A No. 0 165 885 discloses concentrated liquid hard-surface cleaning compositions containing a ternary active system having hydrotroping properties. U.S. Pat. No. 3,591,510 relates to the use of propylene-glycol derivatives in dilute liquid hard-surface cleansers. 
     It is an object of the present invention to provide a liquid hard-surface cleaner composition with excellent cleaning on kitchen and bathroom soils and very good shine performance. 
     It is another object of the present invention to provide a liquid hard-surface cleaner which has a viscosity above 30 cps. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a liquid hard-surface cleaning composition containing 
     from 3% to 10% of surface-active agent 
     from 3% to 10% of a binary solvent mixture consisting of Butyl Carbitol as one of the solvent, and n-butoxy propoxy propanol or Hexyl Carbitol as the other solvent, in a weight ratio of 4/1 to 1/4; 
     from 1% to 10% of a builder and from 0.5% to 8% of a buffer, at a ratio of buffer to builder from 3/1 to 1/3 
     less than 1.5% of hydrotrope. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The surface-active agents, the solvent and the optional ingredients are described in more detail hereinafter. 
     Unless indicated to the contrary, the %-indications stand for &#34;% by weight&#34;. 
     SURFACE-ACTIVE AGENTS 
     Water-soluble detersive surfactants useful herein include well-known synthetic anionic, nonionic, amphoteric and zwitterionic surfactants and mixtures thereof. Typical of these are the alkyl benzene sulfates and sulfonates, paraffin sulfonates, olefin sulfonates, alkoxylated (especially ethoxylated) alcohols and alkyl phenols, amine oxides, sulfonates of fatty acids and of fatty acid esters, and the like, which are well-known in the detergency art. In general, such detersive surfactants contain an alkyl group in the C 10  -C 18  range; the anionic detersive surfactants are most commonly used in the form of their sodium, potassium or triethanolammonium salts. The nonionics generally contain from 3 to 17 ethylene oxide groups per mole of hydrophobic moeity. Especially prreferred in the compositions of the present invention are: C 12  -C 16  alkyl benzene sulfonates, C 12  -C 18  paraffin-sulfonates and the ethoxylated alcohols of the formula RO(CH 2  CH 2  O) n  H, with R being a C 12  -C 15  alkyl chain and n being a number from 3 to 10. 
     Anionic surfactants are frequently present at levels from 3 to 8% of the composition. Nonioic surfactants if used, are typically used at levels between 1% to 5% by weight of the composition. Mixtures of the like surfactants can also be used. The total level of surface-active agents in the present concentrated compositions is from 3% to 10% by weight of the total composition. 
     THE ORGANIC SOLVENT 
     The organic solvent for use herein is constituted by a very specific binary system of a water-soluble solvent and a solvent of low water-solubility. 
     The water-soluble solvent is Butyl Carbitol, i.e. 2-(2-butoxyethoxy)ethanol, and the water-insoluble solvent is selected from the group consisting of n-butoxy propoxy propanol, i.e. 1(2-n-butoxy-1-methylethoxy) propane-2-ol, and Hexyl Carbitol, i.e. 2-(2-hexoxyethoxy)ethanol. n-butoxy propoxy propanol is the preferred solvent of low water-solubility. 
     The weight ratio of Butyl Carbitol to n-butoxy propoxy propanol or Hexyl Carbitol is in the range from 4/1 to 1/4, preferably from 4/1 to 1/1. 
     The total level of solvent is in the range from 3% to 10% of the total composition, preferably 4% to 8%. 
     BUILDER/BUFFER SYSTEM 
     Also critical in the context of the present invention is the Builder/Buffer system. 
     The Builder should be present at levels of from 1% to 10% preferably 1% to 5% by weight of the total composition. 
     Compounds classifiable and well-known in the art as detergent builders include the nitrilotriacetates, (NTA), polycarboxylates, citrates, water-soluble phosphates such as tri-polyphosphate and sodium ortho- and pyro-phosphates, silicates, ethylene diamine tetraacetate (EDTA), amino-polyphosphonates (DEQUEST), phosphates and mixtures thereof. Preferred builder for use in the present invention is sodium citrate. 
     The Buffer is used to adjust and buffer the pH to a 8-11 range, preferably about 10-10.8. It is represented by alkali metal carbonates, preferably sodium carbonate; and present at levels of from 0.5% to 8%, preferably from 1% to 3% of the total composition. the ratio between buffer and builder should be in the range from 3/1 to 1/3, preferably 3/1 to 1/1. 
     PRODUCT VISCOSITY 
     The viscosity of the present compositions is above 30 cps, preferably in the range from 30 to 110 cps, which is substantially higher than current liquid compositions, 3 to 5 cps. 
     These figures apply to viscosity as measured in a Brookfield LVDT viscometer, with Spindle No. 2, at 60 rpm (low shear). 
     Optional components are represented by ingredients typically used in commercial products to provide aesthetic or additional product performance benefits. Typical ingredients include pH regulants, perfumes, dyes, optical brighteners, soil suspending agents, detersive enzymes, gel-control agents, freeze-thaw stabilizers, bactericides, preserrvatives, and the like. 
     There is no need for a thickener in the persent compositions. 
     Hydrotrope can be present, however at levels not exceeding 1.5%. Examples of suitable hydrotropes are urea, monoethanolamine, diethanolamine, triethanolamine and the sodium potassium, ammonium and alkanol ammonium salts of xylene-, toluene-, ethylbenzene- and isopropyl-benzene sulfonates. 
     The compositions herein typically contain water as a carrier. By way of example the water-level can vary in the range from e.g. 40% to 60%. Water-alcohol (e.g., ethanol, isopropanol, butanol, etc.) mixtures can also be used. Alkylated polysaccharides can be used to increase the stability and performance characteristics of the compositions. 
    
    
     The following examples are given by way of illustrating the compositions herein, but are not intended to be limiting of the scope of the invention. 
     ABBREVIATIONS 
     LAS: Sosium Salt of Linear C 11-18  Alkyl Benzene Sulfonate 
     NAPS: Sodium C 13  -C 16  paraffin sulfonate 
     NTA: Sodium nitrilotriacetate 
     n-BPP: n-butoxy propoxy propanol. 
     The following compositions are prepared: 
     
         ______________________________________Ingredient     percentage by weight______________________________________LAS            5      5      4    4    5    --NaPS           --     --     2    1    --   --Lauryl alcohol sulphate          --     --     --   --   --   5Sodium Carbonate          3      3      3    2    4    3Sodium Citrate 1      3      1    --   2    1NTA            --     --     --   2    --   --Butyl Carbitol 4      4      4    3    3    4n-BPP          2      2      --   3    3    2Hexyl Carbitol --     --     2    --   --   --Perfume        0.5    1.0    1.0  0.5  0.5  0.5Dyes, miscellaneous, water          up to 100Product viscosity (cps)          90     100    70   70   110  50______________________________________ 
    
     The above compositions were found to show very good cleaning performance on both kitchen and bathroom soils, and excellent shine performance.