Detergent composition for cleaning dyeing machine
The present invention relates to a detergent for cleaning dyeing machines. More particularly, the invention relates to a detergent suitable for use in cleaning dyeing machines at the time of the switchover of dyeing lots. 
     A dyeing machine (particularly a vessel) is cleaned when a dyeing lot is switched over in dye works because if the machine is not cleaned, a dye, dyeing assistant and contaminants contained in the water used in the preceding lot and remaining on the walls of the dyeing machine would be incorporated in a dyeing bath in the subsequent dyeing lot to cause contamination of the dyeing system, changes in the hue of the fibrous product to be dyed or uneven dyeing thereof or to adhere the contaminates to the fibers, thus inviting troubles such as conversion of the fibers into being hydrophobic or rough and, stiff. 
     The cleaning process varies depending on the degree of staining of the dyeing machine and the subsequent dyeing process. For example, it has been considered that the cleaning of a dyeing vessel is unnecessary when a vessel not stained severely in the preceding lot is used again in the subsequent lot in which a dye of a higher concentration is used as in the case where a cotton is dyed with a reactive dye into a pale color and then with a reactive dye into a similar, darker color. However, even in such a case, the vessel is stained with the dye, etc. which might exert an adverse influence on the dyeing in the subsequent dyeing lot and, therefore, the vessel should be cleaned with a suitable detergent. A thorough washing is necessary when the vessel is stained severely in the preceding lot and the dye concentration in the subsequent lot is low as in the case when polyester fibers are dyed into a dark color with a disperse dye and then into a pale color with a disperse dye. In this case, the vessel is cleaned with a combination of a detergent for the vessel, an alkali and a hydrosulfite at a high temperature. Examples of the detergents for the vessel include aliphatic amine/alkylene oxide adducts, alkylphenol/alkylene oxide adducts, arylphenol/alkylene oxide adducts, fatty acid/alkylene oxide adducts, products obtained by adding an alkylene oxide to a mixture of a fatty acid triglyceride and a polyhydric alcohol, alkylbetaines and quaternary ammonium salts. 
     However, the contaminants in the vessel are composite materials produced by the reaction of the dye, dye assistant and impurities in water used and, therefore, they cannot be removed thoroughly by the detergent for cleaning the dyeing vessel which has only the above-mentioned functions. Thus, in fact, problems are posed that the vessel must be cleaned by repeating the cleaning under the severe conditions as described above or by dyeing waste fibers to remove the dye, etc. remaining in the vessel. Further, it is considered that a tendency of producing varieties of products each in a small amount is increasing and the ratio of the cleaning time to the working time is also increasing. In addition, the bath ratio is now being reduced from the viewpoint of saving energy and resources to pose a problem that the staining of the vessel is accelerated by the increase of the concentration of the contaminants in the dyeing bath. To solve these problems, the development of detergents for cleaning the vessel superior to those used in the prior art is demanded. 
     Summary of the Invention 
     After intensive investigations made for the purpose of solving the above-mentioned technical problems, the inventors have found that the problems can be solved by using a composition comprising components described below as the detergent for the dyeing machines. 
     The invention provides a detergent composition, suitable to clean a dyeing machine, which comprises 
     (a) a water-soluble or water-dispersible polymer of an unsaturated carboxylic acid monomer or a polymerizable derivative thereof and 
     (b-1) an alkylene oxide adduct of an aliphatic compound or an aromatic compound, (b-2) a sulfonate of a monocyclic compound or a condensed polycyclic compound or (b-3) an aliphatic aldehyde condensate of said sulfonate. 
     An embodiment of the invention comprises the component (a) and as the component (b) (b-1)and one of (b-2) and (b-3) in combination. 
     It is optional that said polymer (a) is a copolymer of said two or more monomers. Said derivative may be an alkyl(C1 to C4) ester, an alkali metal salt, an ammonium salt or an organic amine salt of said acid. It is also optional said polymer (a) is a copolymer of said monomer and another monomer. 
     The invention moreover provides a method for cleaning a dyeing machine with a detergent composition as defined above. 
     The invention composition is alternatively defined below. It comprises: 
     (a) a water-soluble or water-dispersible polymer comprising one or more monomers selected from the group consisting of unsaturated carboxylic acids and their derivatives as indispensable component(s), and 
     (b) an alkylene oxide adduct of an aliphatic or aromatic compound and/or a sulfonated monocyclic or condensed polycyclic compound, or an aliphatic aldehyde condensate thereof. 
     Examples of the monomers usable for obtaining the above-mentioned component (a) include unsaturated monocarboxylic acids such as acrylic and methacrylic acids; unsaturated dicarboxylic acids such as maleic acid; derivatives of the acids such as alkyl esters (e.g. methyl esters), alkali metal salts (e.g. sodium salts), ammonium salts and organic amine salts (e.g. triethanolamine salts) of said acids; and mixtures of them. In addition to these monomers, copolymerizable monomers such as vinyl acetate, isobutylene, diisobutylene and styrene may also be used as comonomer components. 
     These monomers are polymerized by a known, ordinary process. Though the proportion of the monomers and the degree of polymerization of them are not particularly limited, the polymer should be at least water-soluble or water-dispersible. 
     Examples of the polymers include polyacrylic acid, polymethacrylic acid, acrylic acid/methacrylic acid copolymer, acrylic acid/methyl acrylate copolymer, acrylic acid/vinyl acetate copolymer, acrylic acid/maleic acid copolymer, maleic acid/isobutylene copolymer and maleic acid/styrene copolymer as well as salts of them with alkali metals, ammonia and organic amines. These polymers may be used either alone or in the form of a mixture of two or more of them. The preferred polymers and copolymers used as the component (a) of the present invention are those having an average molecular weight of 1,000 to 10,000. 
     Examples of the alkylene oxide adducts of the aliphatic or aromatic compounds used as the component (b) in the present invention include alkylene oxide adducts of aliphatic amines, alkylphenols, arylphenols, nonylphenol, fatty acids, fatty acid triglycerides and mixtures of a fatty acid triglyceride with a polyhydric alcohol. 
     Examples of the sulfonated monocyclic and condensed polycyclic compounds and aliphatic aldehyde condensates of them usable as the compound (b) in the present invention include aromatic hydrocarbons such as benzene, naphthalene, fluorene, anthracene, phenanthrene, pyrene, naphthacene, pentacene, coronene, hexene, heptacene, octacene, nonacene, decene, undecacene, dodecacene and acenaphthene; aromatic hydrocarbon mixtures such as creosote oil and cracking products of petroleum; and water-soluble salts of them such as alkali metal, ammonium, alkaline earth metal and alkanolamine salts of them prepared by condensing a sulfonated aromatic compound including derivatives having 1 or 2 alkyl groups having 1 to 5 carbon atoms with formalin. Among them, formalin condensates of naphthalenesulfonic acid salts, ligninsulfonic acid salts and alkylnaphthalene-sulfonic acid salts in which the alkyl group has 1 to 8 carbon atoms are particularly preferred. 
     The detergent of the present invention for cleaning dyeing machines comprises the combination of the above-mentioned components (a) and (b). By using this combination, the problems of the conventional detergents for dyeing machines can be solved. 
     The detergent of the present invention for cleaning dyeing machines contains preferably at least 1 wt. % of the component (a), particularly at least 5 wt. % of the same. 
     Namely, the mixing weight ratio of (a) to (b) is in the range of 1 to 99/99 to 1, particularly 5 to 99/95 to 1. 
     The detergent of the present invention is used in an amount of 0.01 to 20 g (in terms of the solid), preferably 0.04 to 10 g per 1 liter of water which dissolves the same. The cleaning is practically made while the detergent solution is stirred. The deterging power of the composition is advantageously increased by adding thereto a reducing agent such as a hydrosulfite, a condensate between hydrosulfite and formaldehyde, hydroxyethanesulfinic acid and sodium boron hydride and an alkali agent such as sodium hydroxide and potassium hydroxide. 
     Though the mechanism of cleaning the dyeing machines thoroughly with the detergent of the present invention has not fully been understood yet, it may be supposed that the scales deposited on the walls of the dyeing machines are dispersed and removed by high chelating capacity and inorganic substance-dispersing capacity of the component (a) and that the non-fixed dye, reaction products thereof with the alkali and tarry products are removed from the walls of the dyeing machine and redeposition of them is prevented by dye-solubilizing capacity, cleaning power and organic substance-dispersing capacity of the component (b). Thus, thorough cleaning can be effected. 
     Each component to use in the invention composition can be obtained by a conventional preparation process. For example, an acrylic polymer, one of the component (a), can be prepared by adding acrylic acid and ammonium persulfate dropwise to an aqueous solution of iso-propyl alcohol. Sodium salt of a copolymer of acrylic acid and maleic anhydride, another example of the component (a), can be obtained by conducting the aqueous solution polymerization of sodium neutralized products of acrylic acid and maleic anhydride in the presence of ammonium persulfate. The component (b-1) can be prepared by conducting the addition reaction of an alkylene oxide to an aliphatic compound or an aromatic compound at a high pressure at a high temperature. Naphthalene sulfonate, one of the (b-2), can be obtained by a reaction between naphthalene and concentrated sulfuric acid. Then a condensate thereof, one of the (b-3), can be prepared by addition of formalin to the sulfonate and heating of the mixture. 
    
    
     The following composition examples and examples of the detergents will further illustrate the present invention, which by no means limit the invention. 
     (COMPOSITION EXAMPLES) 
     The detergents for cleaning dyeing machines having compositions shown in Table 1 were used. 
     (EXAMPLES) 
     Polyester cloths (Tropical) were dyed with the following dye A at 130° C. in a high-pressure which dyeing machine (a product of Tsujii Senki Kogyo Co., Ltd.) for 30 min with a bath ratio of 1/10 and then the vessel was cleaned at 100° C. under the following conditions B for 30 min: 
     
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A.    C. I. Disperse Red 143,                                             
                        3 g/L, pH 4 (adjusted                             
                        with acetic acid)                                 
B.    detergent for vessel                                                
                        2 g/L                                             
      sodium hydroxide  1 g/L                                             
      sodium hydrosulfite                                                 
                        1 g/L                                             
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     The extent of cleanness of the vessel was determined by effecting a blank dyeing test of white polyester cloths (Tropical) in tap water controlled to pH 4 with acetic acid at 130° C. for 30 min in the high-pressure winch dyeing machine after the cleaning and then examining the degree of coloring of the white cloths. The results are shown in Table 2. 
     A coloring degree is shown with 9 grades, 1, 1-2, 2,-3, 3,-4, 4,-5, 5. The grade 5 means that a test cloth is not colored and the grade 1 means that it is the most colored. It is accordingly noted that the stronger the detergency is, the higher the coloring degree is. 
     
                       TABLE 1                                                     
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(unit: wt. %)                                                             
             Detergent of the present invention for                       
             cleaning the vessel                                          
Components     1     2     3   4   5   6   7   8   9                      
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(1) polysodium acrylate                                                   
                   25    25  30  30  40  50  50  80  90                   
    (molecular weight:                                                    
    about 6000)                                                           
(2) sodium salt of naph-                                                  
                   15    --  20  --  40  --  --  --  10                   
    thalenesulfonic acid/                                                 
    formalin condensate                                                   
    ammonium salt of                                                      
                   --    15  --  20  --  50  --  --  --                   
    naphthalenesulfonic                                                   
    acid/formalin                                                         
    condensate                                                            
(3) EO (15 mol) adduct of                                                 
                   60    --  --  50  20  --  --  20  --                   
    mixture of bone oil                                                   
    and glycerol                                                          
    EO (13 mol) adduct of                                                 
                   --    60  50  --  --  --  50  --  --                   
    styrenated phenol                                                     
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                       TABLE 2                                                     
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                 Degree of coloring of                                    
Detergent for the vessel                                                  
                 white cloth (grade)                                      
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Present invention                                                         
Composition 1    4-5                                                      
Composition 2    4-5                                                      
Composition 3    4-5                                                      
Composition 4    4-5                                                      
Composition 5    4-5                                                      
Composition 6    4                                                        
Composition 7    4-5                                                      
Composition 8    4-5                                                      
Composition 9    4                                                        
Comparative detergent 1                                                   
                 2-3                                                      
Comparative detergent 2                                                   
                 3                                                        
Comparative detergent 3                                                   
                 3                                                        
Comparative detergent 4                                                   
                 3                                                        
Comparative detergent 5                                                   
                 3                                                        
None             2                                                        
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 comparative detergent 1: ammonium salt of naphthalenesulfonic            
 acid/formalin condensate,                                                
 comparative detergent 2: EO (15 mol) adduct of a mixture of bone oil and 
 glycerol,                                                                
 comparative detergent 3: EO (13 mol) adduct of styrenated phenol,        
 comparative detergent 4: laurylbetaine                                   
 comparative detergent 5: polysodium acrylate (molecular weight: about    
 6,000).                                                                  
 
    
     [EFFECTS OF THE INVENTION] 
     When the detergent of the present invention for cleaning dyeing machines is used, the dyeing vessel can be cleaned thoroughly in a short time at the time of the switchover of dyeing lots as shown in the above examples. This effect can be obtained because the detergent of the present invention for cleaning dyeing machines contains, as an indispensable component, a water-soluble or water-dispersible polymer comprising one or more monomers selected from the group consisting of unsaturated carboxylic acids and their derivatives as indispensable component(s).