MXPA96005581A - Concentrates for cleaning, which contain high levels of alc - Google Patents

Abstract

A process for preparing compositions of aqueous, stable cleaning concentrates containing high concentrations of alkali and polymers useful as scaling inhibition additives is disclosed. The water-soluble polymer additives for preparing the stable cleaning concentrates are polymers of acrylic acid and optionally maleic acid, and monomers selected from allyloxy. The storage concentrates, stable to storage, are especially useful for providing cleaning formulations for automatic cleaning systems, such as cleaning operations in place and debotell cleaning.

Description

Concentrates for Cleaning, which contain high levels of alkali.

BACKGROUND The present invention relates to an improved method for preparing stable compositions, for cleaning, soluble in alkali. More particularly, the invention relates to the selection of polymer additives for use in "cleaning compositions which provide homogenous, storable cleaning concentrates, which are useful in cleaning food stains on hard surfaces, such as such as those found in bottle washing and cleaning operations instead (cleaning by circulation) Today's automation has influenced the operations of hotels and restaurants to a point where most of the utensils for eating They are cleaned by means of automatic washing procedures.The detergents used in these applications must have adequate cleaning properties and be provided in a physical form that is easily manageable and that can be added to the cleaning operation in well-defined quantities. Powder cleaning compositions are first made from alkaline inorganic salts, such as phosphates, silicates and carbonat os (known as "constructors"). These powder detergents have the disadvantage of requiring dissolution with water to be able to be added to the automatic washing operation in a controlled manner and in many cases the non-uniform addition of the detergent occurs because the cleaning components easier to dissolve first are sent to the washing operation. Liquid cleaning formulations have been developed to eliminate the disadvantages of powder formulations, but liquid formulations are also limited in their cleaning efficiency, due to the large amount of water that is required to dissolve the cleaning components; In addition, the incompatibility of some cleaning components also limits the preparation of a large index of cleaning formulations in liquid form. Also, the hardness ions (such as calcium, magnesium or barium) naturally present in the rinse water or water used to prepare the concentrate or cleaning solutions, can also aggravate the cleaning problem due to its tendency to react with the solution cleaning and deactivating the building components in the cleaning solution. To counteract the effect of hardness ions, the cleaning compositions contain builders and scale inhibiting components (such as phosphonates) to prevent and minimize the growth of hardness deposits (such as insoluble phosphate, carbonate and sulfate salts) or " scale "on surfaces. The equipment used to manufacture, store or transport food can be stained by a variety of mechanisms, such as residues from degradation during cooking operations and residues from other food preparations and processing operations. Cleaning operations in place (LEL) are used to clean most of the equipment in modern dairy plants, as well as in other food processing operations. LEL operations use a combination of chemical and physical effects to remove surface stains by transporting the cleaning solution to the stained surface and combining the factors of time, temperature, detergent and strength. LEL operations are typically used in pipe line systems, tanks and vats, heat exchange devices, homogenizers and centrifugal machines. Phosphorus-containing compounds (such as phosphates and phosphonates) have been used as builders and inhibitors at the scale of choice in aqueous, previous cleaning solutions, but, due to the increased use of liquid detergents, where sodium tripolyphosphate has a Limited solubility, and to the increased environmental issue in the use of phosphorus-containing builders, alternative compositions have been investigated. However, with 1_ decrease in the use of phosphate, the cleaning characteristic of the cleaning compositions has also decreased. Japanese Patent No. 05-214397 discloses the use of 1 to 50% by weight of poly (ethylene glycol) is carboxylated as e.i builders of solid cleaning formulations containing up to 60% by weight alkali metal hydroxide for automatic dishwashers. US Patent No. 5,273,675 discloses copolymers of acrylic acid and maleic anhydride, optionally containing a carboxyl-free unsaturated monomer, useful in cleaning concentrates containing an active source of chlorine. Despite the large number of liquid cleaning compositions available as hard surface cleaners, there is still a need for liquid cleaning compositions that can be prepared in highly concentrated form in the presence of high concentrations of alkali metal hydroxide, which are stable in the storage and providing satisfactory scale cleaning and inhibition during bottle washing, cleaning of stained food processing equipment or cleaning utensils for eating and drinking. The present invention seeks to solve the problems of the prior art by providing an improved process for preparing stable, alkali-soluble cleaning compositions having satisfactory cleaning and scaling inhibition properties.

DETAILED DESCRIPTION OF THE INVENTION A method for preparing a stable, aqueous cleaning concentrate, comprising combining in an aqueous solution: (a) from 1 to 10 percent, based on the total weight of the cleaning concentrate, of a soluble polymer in water comprising polymerized units: (i) from 20 to 80 percent, based on the total weight of the polymer, of unsaturated monocarboxylic acid monomer selected from one or more acrylic acids, methacrylic acids and water soluble salts thereof; (ii) from 0 to 65 percent, based on the total weight of the polymer, of unsaturated dicarboxylic acid monomer and (iii) from 5 to 50 percent, based on the total weight of the polymer, of non-ionizable, unsaturated monomer, selected from one or more monomers of Formula I: CH2 = C (Ra) CH (R2) OR3, _, wherein: R1 is selected from hydrogen, methyl and -CH20H; R2 is selected from hydrogen, methyl and -CH2OH; R3 is selected from hydrogen, -CH2CH (CH3) OH, -CH2CH2OH and (C3-C2) - containing polyol residues; and (b) from 15 to 50 percent, based on the total weight of the cleaning concentrate, of a ringed metal hydroxide selected from one or more sodium hydroxides and potassium hydroxides.

The present invention further provides an aqueous cleaning concentrate comprising from 1 to 10 percent, based on the total weight of the cleaning concentrate, of a water soluble polymer, as described above, of 15 to 50 percent, based on in the total weight of the cleaning concentrate, of an alkali metal hydroxide selected from one or more sodium hydroxides and potassium hydroxides, and water.

DETAILED DESCRIPTION Water soluble polymer additives, useful in the present invention, contain polymerized units of from 20 to 80 percent (%), preferably from 30 to 70% and more preferably from 40 to 60% of monocarboxylic acid monomer selected from one or more acrylic acids, methacrylic acids and water soluble salts thereof; from 0 to 65%, preferably from 15 to 50%, and more preferably from 20 to 40%, of dicarboxylic acid monomer; and from 5 to 50%, preferably from 10 to 30% and more preferably from 10 to 20% of an unsaturated non-ionizable monomer that is selected from one or more monomers in Formula I; all percentages are by weight and are based on the total weight of the water soluble polymer. The water-soluble salts of the polymer additives can also be used, for example, the alkali metal salts (such as sodium or potassium) and the ammonium or substituted ammonium salts thereof.

In one embodiment of the invention, the water-soluble polymer comprises as polymerized units of 40 to 55% unsaturated monomer of monocarboxylic acid, 30 to 50% of unsaturated dicarboxylic acid monomer and 10 to 20% of non-ionizable monomer.unsaturated In another embodiment of the invention, the water-soluble polymer comprises as polymerized units of 60 to 80% unsaturated monomer of monocarboxylic acid, from 0 to 10% of unsaturated monomer of dicarboxylic acid. and from 20 to 40% unsaturated non-ionizable monomer. Convenient unsaturated nonionizable monomers include, for example, allyl alcohol, 3-allyloxy-1,2-propanediol, allyloxyethanol, allyloxypropanol, monoallyl ether erythritol, monoallyl ether pentaerythritol and 1-butane-3, -diol. Preferred non-ionizable monomers are allyl alcohol and 3-allyloxy-1,2-propanediol. The "unsaturated dicarboxylic acid monomer" as used herein refers to monoethylenically unsaturated dicarboxylic acids containing 4 to 10, preferably 4 to 6, carbon atoms per molecule and anhydrides of cis-dicarboxylic acids. The dicarboxylic acid monomers useful in water-soluble polymer additives of the present invention include, for example, maleic acid, maleic anhydride, glutaric acid a-methylene, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, cyclohexenedicarboxylic acid, anhydride cis-1, 2, 3, 6-tetrahydrophthalic (also known as cis-4-cylcohexene-1,2-dicarboxylic anhydride) and water-soluble salts thereof. Preferred unsaturated dicarboxylic acid monomers are maleic acid and maleic anhydride. The monomers of Formula I can be prepared by a variety of synthetic routes known to those skilled in the art. For example, the allyl chloride can be reacted with several polyhydroxy compounds to give, for example, the corresponding allyloxy derivatives of sugars, glycerin, erythritol and pentaerythritol. Alternatively, the allyl alcohol can be reacted with various halomethyl derivatives, especially chloromethyl compounds, to prepare allyloxy derivatives.; for example, the reaction of the allyl alcohol with epichlorohydrin could produce 3-allyloxy-1,2-propanediol. Vinyl glycols, such as l-butarium-3, -diol, for example, can be prepared by methods such as those described in US Patent No. 5,336,815. Allyloxy compounds that could hydrolyze the allyloxy compounds of Formula I under aqueous polymerization conditions, for example allyl glycidyl ether, are also useful as monomers for producing polymer additives of the present invention. Polyols containing (C3-C? 2) useful for preparing allyloxy compounds of Formula I include, for example, (C3-C6) polyhydroxy compounds such as erythritol, pentaerythritol, and giicerin; and sugar alcohols such as xylitol, sorbitol and mannitol. Additional (C3-C? _) Containing polyols, include, for example, polyhydroxy aldehyde and ketone sugars such as glucose, fructose, galactose, maltose, sucrose, lactose, erythrose and threose. Examples of unsaturated non-ionizable monomers, including representative examples of monomers based on polyols containing (C3-C? 2) (compounds [5], [6], [7], [8], [9] and [10], see groups R3) are shown in Table I. The prefixes "(C3-C? 2) -" and "(C3-C6) -" which are used herein, refer to organic compounds or structural parts of organic compounds containing from 1 to 12 carbon atoms and from 3 to 6 carbon atoms, respectively. The terms "polyol" and "polyhydroxy", which are used herein, refer to organic compounds or structural parts of organic compounds containing two or more hydroxy groups.

Table I Non-ionizing monomers R1 R2 R3 Unsaturated allyl alcohol [1] -H-H -methyl alcohol [2] -CH3 -H-Allyloxyethanol [3] -H-CH2CH2OH allyloxypropanol [4] - H -H-CH2CH (CH3) OH 3-allyloxy-1,2-propanediol [5] -H -H-CH2CH (OH) CH2OH allyloxy (sugar) [6] -H -H - allyloxy (glucose) sugar residue [7] -H -H -CH2 [ CH (OH)] 4C (= 0) H allyloxy (fructose) [8] -H -H -CH2 [CH (0H)] 3C (= 0) CH20H monoallyl erythritol ether [9] -H -H -CH2 [ CH (0H)] 2 CH20H monoallyl ether pentaerythritol [10] -H -H -CH2C (CH20H) 3 l-butane-3,4-diol [11] -H-CH2OH -H The concentration of water soluble polymer additives (active ingredient) in cleaning concentrate compositions of the present invention is from 1 to 10%, preferably from 1 to 5% and more preferably from 1 to 2% by weight of the concentrate. The concentration of the polymer additive in the concentrate composition depends on the amount of other components present that may have an impact on the desired development and compatibility characteristics of the concentrate. For example, if a phosphate-containing compound is present in the cleaning concentrate, the effective amount of the polymer additive needed to achieve the desired cleaning characteristic may be less than if the phosphate-containing compound is not present. The substitution of the polymer additives of this invention for phosphorus-containing compounds (commonly used in cleaning compositions containing phosphate builders) can be considered when the use of phosphates is restricted. The cleaning concentrate compositions of this invention have a liquid form. As used herein, "liquid" also refers to a gel or slurry. The compositions of the concentrate may include additional conventional cleaning additives, well known to those skilled in the art, in amounts of conventional use. Optional, conventional cleaning additives include, for example, builders, sequestrants, water-soluble surfactants, anti-foaming agents, corrosion inhibitors, bleaching agents, stabilizers, anti-stain agents and opacifiers. The amount of optional conventional additives used will usually be from 0 to 40% and preferably from 1 to 20% by weight of the composition of the liquid cleaning concentrate.

The cleaning concentrate compositions of this invention may contain builders, including, for example, salts of inorganic builders such as alkali metal polyphosphates (such as tripolyphosphates and pyrophosphates); ethylenediaminetetraacetic acid, nitrilotriacetate and alkali metal carbonates; water-soluble organic builders such as citrates, polycarboxylates and carboxylates; and monomeric (e.g., aminotrismethylenephosphonic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), hydroxyethoxy-diphosphonic acid, diethylenetriamine-penta (methylene-phosphonic acid), ethylenediamine-tetraethylene-phosphonic acid and salts thereof), oligomeric and polymeric phosphonates . The amount of the builder used will usually be from 0 to 10%, preferably from 2 to 5%, by weight of the liquid cleaning concentrates. The cleaning concentrate compositions of this invention may also contain an alkali metal silicate builder in a concentration of 0 to 10% and preferably 3 to 5% by weight of the concentrate. The most preferred alkali metal silicates are sodium silicates. Although the alkali metal silicates are an optional component of the present invention, the silicates are beneficial when the corrosion inhibition of the metal parts is desired, since the fret washing compositions, high er. alkaline, which do not contain silicates can attack aluminum pans and pans and other metal utensils. Although optional, the cleaning concentrate compositions of this invention will usually contain a low foaming wetting agent, usually in the form of a water-soluble surfactant, for example, non-ionic and amphoteric surfactants in a concentration of 0 to 2% and preferably from 0.5 to 1% by weight of the concentrate. Low-foaming wetting agents are preferred for concentrate compositions since foam can reduce the mechanical efficiency of rinse cycles or wash sprays of certain types of cleaning operations. Amphoteric, zwitterionic, non-anionic, anionic, water-soluble, low-foaming surfactants or combinations thereof can be employed. Optionally, the cleaning concentrate compositions of this invention may contain bleaching agents, for example chlorine-generating substances (such as sodium hypochlorite or chloroisocyanurates), peroxides, sulfites and perborates. Preferably, the concentrate compositions do not contain bleaching agents that generate chlorine. In addition, the compositions of the cleaning concentrate of this invention may contain sequestrants, such as sodium gluconate in concentrations of 0 to 5% and, preferably, 1 to 2% by weight of the concentrate.

It has been found that the characteristic of the polymer additives used in the present invention does not depend on the molecular weight, provided that the molecular weight of the polymer does not affect, adversely its compatibility with other components of the cleaning compositions. The weight average molecular weights (Mw) of the polymer additives of the present invention are typically from 1,000 to 100,000, preferably from 2,000 to 40,000, more preferably from 3,000 to 15,000 and, more preferably, from 4,000 to 10,000, as measured by aqueous gel permeability chromatography (CPG).

Due to their solubility properties, polymer additives are useful in cleaning solutions that contain high levels of caustics. Polymer additives are useful in these detergent compositions as scale inhibitors, dispersants, sequestrants and anti-precipitants; however, many polymers of the prior art, such as poly (acrylic acid) and copolymers of maleic acid with acrylic acid, can not be used in these applications because they are not soluble in highly caustic solutions. In addition, to provide the preparation of stable cleaning concentrates in storage, the water soluble polymer additives are useful in the cleaning solutions prepared by other methods. For example, the cleaning solutions can be prepared by combining, as separate components, the water-soluble polymer additive, from 20 to 50% of an aqueous solution of the alkali metal hydroxide and draws (sufficient for dilution), wherein the polymer , the alkali metal hydroxide solution and water are separated as separate streams in an inline mixing system. Optionally, an aqueous solution of conventional cleaning additives may also be added as a separate corrience or used in place of the dilution water component when preparing the cleaning solutions. The resulting cleaning solutions obtained either by diluting the cleaning concentrate compositions of the present invention or by other methods, such as those described above, typically contain: (a) from 0.005 to 0.4% , preferably from 0.01 to 0.1%, of the additive of water-soluble polymer, (b) from 0.1 to 3%, preferably from 0.2 to 2% and, more preferably, from 0.5 to 1.5% of an alkali metal hydroxide , (c) water and, optionally, (d) from 0.001 to 2% of conventional cleaning additives; all concentrations are based on the total weight of the cleaning solution. The use of water soluble polymer additives in cleaning solutions (diluted from concentrates or prepared by other methods) provides a method for cleaning hard surface materials, comprising contacting a stained, hard surface material with an effective amount of cleaning solution containing the water-soluble polymer additive until the substantial removal of the stain is complete.

The aqueous solutions of cleaning compositions of the present invention are effective in cleaning stained surfaces over an extensive wash water temperature index, typically from 5 to 95 ° C, preferably from 30 to 80 ° C and, more preferably , from 50 to 70 ° C. The concentrations of alkali metal hydroxide (sodium hydroxide or potassium hydroxide) in cleaning concentrate compositions of the present invention vary from 15 to 50%, preferably from 20 to 50% and more preferably from 25 to 40%, based on the weight of the cleaning concentrate. A typical caustic composition of the cleaning concentrate contains 50 to 85% "caustic" or "soda bar" (such as 50% aqueous eodium hydroxide), 1 to 2% "polymer additive" and * 0 to 40% of cleaning additives, conventional, optional, with the rest that is water. The concentrations of alkali metal hydroxide in the cleaning concentrate may vary depending on the end-use application. For example, the dishwashing cleaning concentrates typically contain from 5 to 20% by weight alkali metal hydroxide, the cleaning concentrates in place typically contain from 10 to 30% by weight of alkali metal hydroxide and the concentrates of Cleaning for bottle washing typically contains more than 35% by weight of alkali metal idroxide. The liquid compositions of cleaning concentrates of the present invention are typically prepared by dissolving the conventional polymer additive and optional cleaning additives in the desired amount of caustic (with refrigeration) to provide the homogeneous liquid cleaning concentrate. Cleaning concentrates are typically diluted with water to provide the current cleaning solutions used to contact stained hard surface materials Cleaning solutions are formed by diluting the cleaning concentrates from 0.1 to 5% by weight of the cleaning solution with water The method of the present invention provides physically stable, aqueous compositions of cleaning concentrates that remain homogeneous in storage, that is, they are not stabilized, separated or precipitated in different phases / The components of the liquid compositions of cleaning and its relative proportions are sel They are produced in such a way that they are compatible with one another, resulting in homogeneous liquid formulations. In general, the satisfactory stability or compatibility of the polymer additives of the present invention in the cleaning concentration is indicated if precipitation or phase separation has not occurred at room temperature for at least 1 week, preferably for at least 4 weeks. weeks, more preferably, for at least 8 weeks and more preferably, for at least 6 weeks when the polymer additive is present at 1%, preferably 2% by weight in the cleaning concentrate (containing from 35 to 40 % by weight of sodium hydroxide). The polymer additives useful in the present invention can be made by the polymerization methods well known to those skilled in the art. Polymerizations can be conducted as continuous or semi-continuous, co-feeding, bead processes. When the polymerization is conducted by an almost bead process, or all of the one or more non-ionizable unsaturated monomers and any of the unsaturated dicarboxylic acid monomers, if used, are present in the reactor and the one or more unsaturated monomers of Monocarboxylic acid are fed to the reactor out of time. In general, the feeds are conducted for periods of time from 5 minutes to 5 hours, preferably from 30 minutes to 4 hours and, more preferably, from 1 hour to 3 hours. When the polymerization is carried out by a co-feeding process, the initiator and the monomers are introduced into the reaction mixture as separate feed streams that are added linearly out of time, ie at constant rates. Optional components of the reaction mixture, such as unsaturated dicarboxylic acid monomers, neutralizing solutions, chain regulators and metals, may also be fed into the reaction mixture as separate feed streams or combined with one or more other streams. of food. Preferably, the optional components are present in the bead. If desired, the currents can be alternated so that one or more streams are completed before the others. If desired, a portion of the monocarboxylic acid and non-ionizable monomers and the dicarboxylic acid monomers, if used, and / or a portion of the initiators may be added to the reactor before the addition of the monomers begins. The monomers may be fed into the reaction mixture as individual feed streams or combined in one or more feed streams. The process by which the polymer additives of the present invention can be prepared can be aqueous, solvents or by emulsion polymerization; they are preferably prepared by aqueous processes, that is, substantially free of organic solvents. The water may be introduced into the reaction mixture initially, as a separate feed stream, as the solvent for one or more of the other components of the reaction mixture or some combination thereof. Generally, the polymerizations have final solid levels in the index of 20 to 80%, preferably 30 to 70%, by weight of the reaction mixture. The temperature of the polymerization reaction will depend on the choice of initiator and target molecular weight. In general, the polymerization temperature is above the boiling point of the system, although the polymerization can be conducted under pressure if higher temperatures are used. Generally, the temperature of the polymerization is from 25 to 120 ° C and preferably from 65 to 110 ° C. Suitable initiators for preparing the polymer additives of the present invention are any of the conventional initiators that are soluble in water. Among the suitable initiators that can be used are the free-radical thermal initiators, such as hydrogen peroxide, certain alkyl hydroperoxides, dialkyl peroxides, persulfates, peresters, percarbonates, ketone peroxides and azo initiators. Specific free radical initiators include, for example, hydrogen peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, tert-amyl hydroperoxide and ketone peroxide. methyl ethyl. Free radical initiators are typically used in amounts of 0.5 to 25%, based on the total weight of the monomer. The amount of the initiator used will vary according to the desired molecular weight of the resulting polymer and the relative amount of both the unsaturated non-ionizable monomers and the optional unsaturated dicarboxylic monomers, greater amounts of initiator are preferred, while the relative amount of the initiator is preferred. optional dicarboxylic acid monomer and the non-ionizable unsaturated monomer increase, or as long as the desired molecular weight of the polymer decreases Water-soluble redox initiators may also be used Redox initiators include, for example, sodium bisulfite, sodium sulfite, hypophosphites , phosphites, isoascorbic acid, sodium formalehyde sulfoxylate and hydroxylamines, used in conjunction with suitable oxidizing agents, such as the free radical thermal initiators indicated above.Redox initiators are typically used in amounts of 0.05 to 10%, preferably from 0.5 to 5%, based on the weight of the total monomer. Initiator combinations can also be used. A preferred method for making the polymers of the present invention utilizes both a free radical initiator and a redox initiator. A particularly preferred combination of initiators is persulfate and peroxide. In one embodiment of the present invention, one or more metal salts, soluble in water, can be used to promote the polymerization and to control the molecular weight of the resulting polymers. Metal salts, soluble in water, such as copper, iron, cobalt and manganese salts, are typically used at levels of 1 to 200 parts per million (ppm), preferably 3 to 100 ppm of the metal ion, based on in the weight of the polymerizable monomers. The preferred metal salts are copper and iron salts, which include all organic and inorganic compounds that will generate copper or iron ions in aqueous solution. Suitable salts include, for example, sulfates, nitrates, chlorides, acetates and gluconates. It is usually desired to control the pH of the polymerization monomer mixture using either a redox initiator or a thermal initiator. The pH of the polymerization monomer mixture can be controlled by a brake system or by the addition of a suitable acid or base. The pH of the system can be adjusted to adapt the choice of the redox system by the addition of "a suitable acid or base, If it's necessary. In processes where all or some of the monomers are gradually added to the reaction mixture, the pH of the reaction mixture can also be controlled by gradual addition of a neutralizer. Examples of suitable neutralizers include, for example, sodium, potassium or ammonium hydroxide and amines, such as triethanolamine and ammonia-water. These neutralizers are used in aqueous solutions and can be added gradually in the reaction mixture as a separate feed stream or as part of one of the other feed streams. Typical neutralizing levels are from 20 to 95% base equivalent, preferably from 20 to 80% base equivalent, based on the total acid functionality of the monomer components.

The polymerization processes for the preparation of polymer additives used in the present invention usually result in a good conversion of the monomers into the polymer product. However, if the residual monomer levels in the polymer mixture are high, without wishing, for a particular application, their levels can be reduced by one of several techniques. A common method for reducing the residual monomer level in a polymer mixture is the post-polymerization addition of one or more reducing agents or initiators to assist in the ejection of the unreacted monomer. Preferably, any post-polymerization addition of reducing agents or initiators is conducted at the polymerization temperature - or below that polymerization temperature. Suitable reducing agents and initiators to reduce the residual monomer content are well known to those skilled in the art. Generally, any of the suitable initiators for the polymerization is also suitable for reducing the residual monomer content of the polymer mixture. The level of reducing agents or initiators added as a means to reduce the residual monomer content should be as low as possible to minimize contamination of the product. Usually, the level of the reducing agent or initiator added to reduce the residual monomer content is in the proportion of 0.1 to 2.0 mole%, preferably 0.5 to 1.0 mole%, based on the total amount (moles) of the polymerizable monomer. The polymers of the present invention are soluble in water. The solubility in water is affected by the molecular weight of the polymers and the relative amounts and hydrophilicity of the monomer components incorporated in the polymer. If desired, chain transfer agents or chain regulators can be used to assist in the control of the molecular weight of the polymers. Any conventional agent, water soluble, chain transfer or chain regulator can be used. Suitable chain regulators include, for example, mercaptans, hypophosphites, phosphites, alcohols and bisulfites. If used, mercaptans (such as 2-mercaptoethanol), bisulfites (such as sodium metabisulfin) or hypophosphites are preferred. Some of the embodiments of the invention are described in detail in the following Examples. All proportions, parts and percentages (%) are expressed by weight, unless otherwise specified, and all reagents used are of good commercial quality, unless otherwise indicated. EXAMPLE 1 To a four-neck, 5-liter flask, equipped with a mechanical stirrer, reflux condenser, thermometer and inlets for the gradual addition of monomers, caustic solution and initiator solution, was added 75.00 grams of deionized water, 1.60 grams of a 0.15% solution of CuS0.5H20 and 35.00 grams of 3-allyloxy-1,2-propanediol. The contents of the flask were heated to 92 ° C. A monomer solution of 65.00 grams of glacial acrylic acid, a neutralizer solution of 65.00 grams of 50% sodium hydroxide and an initiator solution of 23.50 grams of 30% H202 were added linearly and separately in the flask while stirring during two hours. Once the additions were completed, the system was maintained at 92 ° C for thirty more minutes, then 0.50 grams of sodium persulfate in 5.00 grams of water was added. The system was then cooled to 60 ° C. The resulting polymer solution had a pH of 6.1 and a solids content of 44.1%. The weight average molecular weight (Mw) was 8.640 and the number average molecular weight Mn) was 5.570. The residual content of acrylic acid was not detected (detection limit = 45 ppm). Example 2 To a four-necked, one-liter flask equipped with a mechanical stirrer, reflux condenser, thermometer and inlets for the gradual addition of monomers, caustic solution and initiator solution, were added 165.00 grams of deionized water and 60.00 grams of allyl alcohol. The contents of the flask were heated to 89 ° C. Next, 10% of both the Monomer Pollution containing 140.00 grams of glacial acrylic acid and an initiator solution containing 16.00 grams of sodium persulfate in 50.00 grams of deionized water were added. After an exotherm of 2-3 ° C, the remaining monomer, initiator and 140.00 grams of 50% aqueous sodium hydroxide were added linearly and separately in the flask while stirring for two hours. Once the additions were complete, the system was maintained at 92 ° C for thirty more minutes. The reaction mixture was then diluted with 70.00 grams of deionized water and the residual allyl alcohol was removed by distillation. The resultant polymer solution had a pH of 6.3 and a solids content of 39.4%. The Mw was 8,480 and the Mn was 5,050. The residual content of acrylic acid was 301 ppm with no residual allyl alcohol detected. EXAMPLE 3 To a 0.5-liter, four-necked flask equipped with a mechanical stirrer, flow condenser, thermometer and inlets for the gradual addition of monomers, chain transfer agent and initiator solution, 45.00 grams of deionized water was added. , 52.00 grams of maleic acid, 60.90 grams of 50% aqueous sodium hydroxide and 13.00 grams of allyl alcohol. The contents of the flask were heated to 90 ° C. Next, 50% of a solution containing 5.20 grams of sodium hypophosphite in 45.00 grams of deionized water was added. This was followed by the addition, while stirring, of 65.00 grams of glacial acrylic acid and the remaining solution of hypophosphite as separate feed streams for 120 minutes and 105 minutes, respectively. Once the additions were completed, the system was maintained at 92-94 ° C for 30 minutes. The polymer solution was diluted with 51 grams of deionized water and 52.3 grams of 50% sodium hydroxide and concentrated to 48.7% solids by distillation. The resulting polymer solution had a pH of 6.5. The Mw was 3,870 and the Mn was 3,280. The residual content of acrylic acid was 781 ppm and the residual content of maleic acid was 1161 ppm. Example 4 To a 0.5-liter, four-necked flask equipped with a mechanical stirrer, reflux condenser, thermometer and inlets for the gradual addition of monomers, chain transfer agent and initiator solution, 58.00 grams of water were added. deionized, 32.50 grams of maleic acid, 19.50 grams of 3-allyloxy-l, 2-propanediol, 3.00 grams of 0.15% FeS04.7H20 and 16.80 grams of 50% aqueous sodium hydroxide. The contents of the flask were heated to 85 ° C and the following feed streams were then added linearly and separately in the flask while stirring for two hours: 78.00 grams of glacial acrylic acid, a solution of 3.25 grams of sodium persulfate at 20.00 grams of deionized water and a solution of 13.00 grams of metabisulfite were dissolved in 35.00 grams of deionized water. Once the additions were completed, the system was maintained at 85 ° C for 30 minutes, then cooled to 77 ° C. This was followed by the addition of 0.12 grams of sodium persulfate in 5.00 grams of deionized water. After stirring for 5 minutes, another solution of 0.12 grams of sodium persulfate in 5.00 grams of deionized water was added. Then, the solution was diluted with 40.00 grams of deionized water and the pH adjusted by the gradual addition of 98.80 grams of 50% aqueous sodium hydroxide.

The resulting polymer solution had a pH of 6.5 and a Solids content of 43.0%. The Mw was 8,350 and the Mn was 5,140. The residual content of acrylic acid was 1900 ppm and the residual content of maleic acid was 4100 ppm. Examples 5-54. Alkali Sulbility and Storage Stability of Cleaning Concentrates. The polymer additives of the present invention were tested for alkali solubility and storage stability, by the following method: 2.0 grams of polymer solids were added to a 118 '' milliliter (4 ounce) glass bottle. followed by the addition of water so that the total weight was 20.00 grams, then, in this solution, in an ice-water bath, 80.00 grams of 50% sodium hydroxide was added, stirring it, so that the temperature did not exceed 25 ° C. The solution was maintained before making the observations The alkali solubility and storage stability of the polymer additives of the present invention was indicated if precipitation or separation had not occurred. from phase to room temperature for at least 1 week (see Table 2) The solubility data in the Table are based on the polymer additives tested at 2% by weight in 80% caustic (50% by weight). sodium hydroxide) Certain polymer additives were also tested at 1% by weight in 80% "caustic" for extended periods of time; these data are indicated as signs in the column of Solubility of Alcali, designing the minimum number of weeks (4 or 8) in which they were soluble at 1% of the level. The abbreviations used in the Table are listed below with the corresponding descriptions; the compositions of the polymer additives are designed by the relative proportions of acrylic acid, maleic acid and the unsaturated non-ionizable monomer (X). Examples 5, 6 and 14 represent the comparative (comp) compositions of the polymer additives which do not they contain unsaturated non-ionizable monomers. Polymer additives containing 50 to 70% AA, 11 to 31% MALAC and 11 to 31% HEA were also evaluated for solubility in high caustic concentrates and were found to be insoluble under the above conditions described.

AA Acrylic acrylic MALAC Maleic acid AOP 3-Allyloxy-1, 2-Propanediol ALC Allyl alcohol AOE Allyloxyethanol HEA Hydroxyethyl acrylate NA Not analyzed + Soluble in caustic Insoluble in caustic Table 2 Composition of Solubility Additive Efficiency Alkali Polymer Mw Anti-Stain Ex # (AA / MALAC / X) 5 100/0/0 (comp) 4,500 - 2.5 6 100/0/0 (comp) '2,000 - 3.5 7 90/0/10 AOP 3,640 - NA 8 85/0/15 AOP 3,730 - NA 9 75/0/25 ALC 8,920 + NA 75/0/25 AOE '12,100 - NA 11 70/0/30 ALC 8,480 + 5 12 70/0/30 AOP 8,570 - NA 13 70/20/10 ALC * 4,250 +4 0.5 14 70/30/0 (comp) 30,000 - NA 65/0/35 AOE 6,770 - NA 16 65/0/35 AOP 10,300 - NA 17 65/0/35 AOP 8,460 + NA 18 65/15/20 ALC 4,670 + 0.5 i 19 65/15/20 AOP 4,440 + 0.5 65/20/15 ALC 4,830 + 0 21 62/0/38 AOP 32,000 - NA 22 62/0/38 ALC; 5,910 + NA 23 62/0/38 AOEr 7,410 - NA 24 60/10/30 AOP 7,340 + NA 60/15/25 AOP 9,530 + 0 26 60/15/25 AOP; 4,680 + 0 27 60/15/25 ALC! 6,620 + 1 28 60/15/25 AOE 6,580 + NA 29 60/20/20 AOP 4,220 + 0 60/25/15 ALC 3,390 AND 0 31 60/25/15 ALC; 4,880 + 0 32 60/25/15 AOP 8.350 +8 0.5 33 55/25/20 AOP 4,960 +4 0 34 55/25/20 AOP 3,680 +4 0.5 55/30/15 AOP 3,570 + NA 36 55/30/15 AOP "8.260 + 0.5 37 55/30/15 AOP 11,800 +8 0.5 38 55/35/10 AOP 3,950 - NA 39 53/35/12 AOP 4,570 + NA 40 50/40/10 ALC 3,870 +4 0 41 50/40/10 AOP 4,320 - NA 42 50/38/12 AOP 4,380 + NA 43 50/38/12 AOP 5,950 + NA 44 50/35/15 AOB 3,010 +4 0.5 45 50/35/15 AO? 4,430 +4 0.5 46 50/35/15 AOP 6,740 + 0 47 50/35/15 AOP 8,870 +8 0.5 48 50/35/15 AOP 11,600 +8 0.5 49 50/35/15 ALC 3,200 +4 0.5 50 50 / 30/20 AOE 4,650 - NA 51 50/30/20 AOP 4,850 +4 0 52 43/38/19 AOP 5,510 + NA 53 40/40/20 AOP '4,790 + NA 54 35/50/15 AOP 4,070 +8 0.5 Ex amp 'Scale Inhibition - Test Method The polymer additives of the present invention were evaluated for scale inhibition (anti-stain efficiency) under conditions simulating temperature and caustic concentrations (0.5% sodium hydroxide at 60 ° C). C) found in LEL operations and bottle washing, determining the amount of the carbonate scale formed on microscopic surfaces after storage at 60 ° C during the night. Aqueous test solutions were prepared containing the required amount of caustic (sodium hydroxide) and 200 ppm ", 0.02% by weight) of polymer additive; the hardness of the water was equivalent to 400 ppm (as CaCO3). The microscopic surfaces were placed in precipitation buckets containing the test solutions and the precipitation buckets and their contents were maintained at 60 ° C overnight (approximately 14 to 18 hours). The microscopic surfaces were then removed from the precipitation buckets and their cleanliness evaluated: "0" represented "no carbonate scale" (clean surface) and "5" represented "strong carbonate scale" (surface completely covered by a layer) white carbonate). Anti-stain values are added in Table 2. Anti-stain values of 0.5 were typical for conventional scale inhibitors of < "Phosphonate used alone (without polymer additives) at 100 ppm in the presence of 0.5% sodium hydroxide Usually, inhibition at a satisfactory scale is indicated by anti-stain values of less than or equal to 2- 3, give preference less than or equal to 1 and more preferably less than or equal to 0.5.

Claims (16)

Claims

1. A method for preparing a stable, aqueous cleaning concentrate, comprising combining in an aqueous solution: (a) from 1 to 10 percent, based on the total weight of the cleaning concentrate, of a water-soluble polymer comprising as polymerized units: (i) from 20 to 80 percent, based on the total weight of the polymer, of unsaturated monomer of monocarboxylic acid selected from one or more of acrylic acid, methacrylic acid and water soluble salts thereof; (ii) from 0 to 65 percent, based on the total weight of the polymer, of unsaturated dicarboxylic acid monomer; and (iii) from 0 to 50 percent, based on the total weight of the polymer, of non-ionizable unsaturated monomer selected from one or more monomers of Formula I: CH2 = C (R ^) CH (R2) OR3 (I) wherein: R1 is selected from hydrogen, methyl and -CH2OH; R2 is selected from hydrogen, methyl and -CH2OH; R3 is selected from hydrogen, -CH2CH (CH3) OH, -CH2CH2OH and (C3-C12) - containing polyol residues; and (b) from 15 to 50 percent, based on the total weight of the cleaning concentrate, of an alkali metal hydroxide that is selected from one or more of sodium hydroxide and potassium hydroxide.

2. The method according to claim 1, wherein the water-soluble polymer comprises as polymerized units of 40 to 55 percent unsaturated monomer of monocarboxylic acid, 30 to 50 percent unsaturated monomer of dicarboxylic acid, and to 20 weight percent of non-ionizable unsaturated monomer.

3. The method according to claim 1, wherein the water soluble polymer comprises as polymerized units of 60 to 80 percent unsaturated monomer of monocarboxylic acid, 0 to 10 percent unsaturated monomer of dicarboxylic acid, and to 40 weight percent of non-ionizable unsaturated monomer.

4. The method according to claim 1, wherein the non-ionizable unsaturated monomer is selected from one or more of allyl alcohol and 3-allyloxy-1,2-propanediol. The method according to claim 1, which comprises combining from 25 to 40 percent, based on the total weight of the cleaning concentrate, of alkali metal hydroxide in the aqueous solution. 6. The method according to claim 1, comprising combining from 1 to 2 percent, based on the total weight of the cleaning concentrate, of water-soluble polymer in the aqueous solution. The method according to claim 1, further comprising combining from 1 to 20 percent, based on the total weight of the cleaning concentrate, of conventional cleaning additives that are selected from one or more of the builders, sequestering agents. , water-soluble surfactants, anti-foam agents, corrosion inhibitors, bleaching agents, stabilizers, anti-stain agents and opacifiers. 8. An aqueous cleaning concentrate comprising: (a) from 1 to 10 percent, based on the total weight of the cleaning concentrate, of a water soluble polymer comprising as polymerized units: (i) from 20 to 80 percent by weight percent, based on the total weight of the polymer, of unsaturated monomer of monocarboxylic acid selected from one or more of acrylic acid, methacrylic acid and water-soluble salts thereof; (ii) from 0 to 65 percent, based on the total weight of the polymer, of unsaturated dicarboxylic acid monomer; and (iii) from 5 to 50 percent, based on the total weight of the polymer, of non-ionizable unsaturated monomer selected from one or more monomers of Formula I: CH2 = C (R1) CH (R2) OR3 (I) in where: R1 is selected from hydrogen, methyl and -CH2OH; R2 is selected from hydrogen, methyl and -CH2OH; R3 is selected from hydrogen, -CH2CH (CH3) OH, -CH2CH2OH and (C3-C12) - containing polyol residues; and (b) from 15 to 50 percent, based on the total weight of the cleaning concentrate, of an alkali metal hydroxide that is selected from one or more of sodium hydroxide and potassium hydroxide, (c) water. 9. The cleaning concentrate according to claim 8 ', wherein the polymer has a weight average molecular weight of 4,000 to 10,000. 10. The cleaning concentrate according to claim 8, further comprising from 1 to 20 percent, based on the total weight of the cleaning concentrate, of conventional cleaning additives selected from one or more of the builders, sequestrants, water-soluble surfactants, anti-foam agents, corrosion inhibitors, bleaching agents, stabilizers, anti-stain agents and opacifiers. 11. A cleaning solution formed by diluting the cleaning concentrate of claim 8 in 0.1 to 5 weight percent of the cleaning solution with water. 12. A method for cleaning hard surface materials, comprising contacting a hard surface material soiled with an effective amount of the cleaning solution of claim 11. 13. A cleaning solution comprising: (a) from 0.005 to 0.4 percent, based on the total weight of the cleaning solution, of a water-soluble polymer comprising as polymerized units: (i) from 20 to 80 percent, based on the total weight of the polymer, of an unsaturated monomer of monocarboxylic acid selected from one or more of acrylic acid, methacrylic acid and water soluble salts thereof; (ii) from 0 to 65 percent, based on the total weight of the polymer, of an unsaturated dicarboxylic acid monomer; Y (iii) from 5 to 50 percent, based on the total weight of the polymer, of a non-ionizable unsaturated monomer selected from one or more monomers of Formula I: CH2 = C (R1) CH (R2) OR3 (I) in wherein: R1 is selected from hydrogen, methyl and -CH2OH; R2 is selected from hydrogen, methyl and -CH2OH; R3 is selected from hydrogen, -CH2CH (CH3) OH, -CH2CH2OH and (C3-C2) - containing polyol residues; and (b) from 0.1 to 3 percent, based on the total weight of the cleaning solution, of an alkali metal hydroxide that is selected from one "plus of sodium hydroxide and potassium hydroxide. (c) water. The cleaning solution according to claim 13, further comprising from 0.001 to 2 percent, based on the total weight of the cleaning solution, of conventional cleaning additives selected from one or more of the builders, sequestrants, water-soluble surfactants, anti-foam agents, corrosion inhibitors, bleaching agents, stabilizers, anti-stain agents and opacifiers. A method for preparing the cleaning solution according to claim 13, comprising combining, as separate components, the water-soluble polymer, from 20 to 50 percent of an aqueous solution of alkali metal hydroxide and water; wherein the polymer, the alkali metal hydroxide solution and the water are added as separate streams in an in-line mixing system. 16. A method for cleaning hard surface materials, comprising contacting a hard surface stained material with an effective amount of the cleaning solution of claim 13.