USOO7449439B2 (12) United States Patent (10) Patent No.: US 7.449,439 B2 to et al. (45) Date of Patent: Nov. 11, 2008 (54) WATER-SOLUBLE THICKENER AND LIQUID (56) References Cited ACDIC DETERGENT U.S. PATENT DOCUMENTS (75) Inventors: Kenji Ito, Aichi (JP); Yoshio Mori, 3,768,565 A 10, 1973 Persinski et al. Aichi (JP) (Continued) (73) Assignee: Toagosei Co., Ltd., Tokyo (JP) FOREIGN PATENT DOCUMENTS (*) Notice: Subject to any disclaimer, the term of this JP 53-463O2 A 4f1978 patent is extended or adjusted under 35 U.S.C. 154(b) by 455 days. (Continued) (21) Appl. No.: 10/530,179 OTHER PUBLICATIONS International Search Report PCT/JP2003/012764 dated Dec. 9, 2003. (22) PCT Filed: Oct. 6, 2003 (Continued) (86). PCT No.: PCT/UP03/12764 Primary Examiner Brian PMruk S371 (c)(1), (74) Attorney, Agent, or Firm Sughrue Mion, PLLC (2), (4) Date: Apr. 4, 2005 (57) ABSTRACT (87) PCT Pub. No.: WO2004/031314 A water-soluble thickener which is highly effective even in PCT Pub. Date: Apr. 15, 2004 thickening strongly acidic aqueous Solutions and has excel lent stability in such solutions. It comprises a water-soluble (65) Prior Publication Data copolymer having a weight-average molecular weight of 6,000,000 or higher obtainable by polymerizing a monomer US 2006/OO46949 A1 Mar. 2, 2006 mixture which comprises 2-acrylamido-2-methylpropane (30) Foreign Application Priority Data Sulfonic acid and/or a salt thereofandacrylic acid and/or a salt thereofas essential components and optionally one or more Oct. 4, 2002 (JP) ............................. 2002-292975 other copolymerizable monomer components including the Oct. 4, 2002 (JP) ............................. 2002-292977 compound represented by the following Formula (1) and/or a salt thereof, wherein the 2-acrylamido-2-methylpropane (51) Int. Cl. sulfonic acid and/or a salt thereof represents 20 mol % or CLID 3/37 (2006.01) more of all the monomers. CLID 7/08 (2006.01) CSF 2/30 (2006.01) (1) (52) U.S. Cl. ....................... 510/475,510/191; 510/199; HC=CHC-O-F-CHCH-C-O--H 510/238; 510/492; 510/499; 526/72; 526/83; O O 526/85; 526/286; 526/310 (58) Field of Classification Search ................. 510/191, 510/199, 238,475, 492,499; 526/72, 83, (wherein n is an integer of 1 to 12). 526/85, 286,310 See application file for complete search history. 7 Claims, 2 Drawing Sheets US 7,449,439 B2 Page 2 U.S. PATENT DOCUMENTS JP 2001-172689 A 6, 2001 JP 2001-220545 A 8, 2001 3,931,089 A 1, 1976 Karl JP 2002-275.204 A 9, 2002 6,066,315 A * 5/2000 Melby et al. ............. 424.70.16 WO WOOO/35961 A1 6, 2000 2004/0028637 A1 2/2004 Villard et al. ............ 424/70.16 WO WOO1/97772 * 12/2001 WO WOO1f97772 A1 12/2001 FOREIGN PATENT DOCUMENTS OTHER PUBLICATIONS JP 04-2097OO 7, 1992 JP 09-143498 6, 1997 Database WPI, Section Ch, Week 200155, Derwent Publications JP 9-157130 6, 1997 Ltd., London, GB, Class A14, AN 2001-499642, Abstract for JP JP 10-279636 10, 1998 2001-172689 A (Lion Corp), Jun. 26, 2001. JP 2000-44996 2, 2000 Database WPI, Section Ch, Week 200343, Derwent Publications JP 2001-114641 4/2001 Ltd., London, GB, Class A14, AN 2003-451387, Abstract for JP JP 2001-114642 4/2001 2002-275204 A (Nippon Kayaku KK), Sep. 25, 2002. JP 2001-115135 4/2001 * cited by examiner U.S. Patent Nov. 11, 2008 Sheet 1 of 2 US 7.449,439 B2 FIG. I. U.S. Patent Nov. 11, 2008 Sheet 2 of 2 US 7.449,439 B2 US 7,449,439 B2 1. 2 WATER-SOLUBLE THICKENER AND LIQUID metic products or the like. However, their thickening effect is ACDIC DETERGENT unsatisfactory in strongly acidic detergents such as those comprising about 10% by weight of hydrochloric acid and TECHNICAL FIELD having a pH value of 1 or less. Moreover, in the processes of preparing copolymers com The present invention relates to a thickener which is effec prising crosslinking monomers as described in JP-A-9- tive even in thickening strongly acidic solutions and is stable 157130, JP-A-2001-114642, JP-A-2001-115135, etc., there in Such solutions, and to a liquidacidic detergent consisting of are problems that high molecular weight water-soluble poly the thickener, which can be used commonly in the relevant mers having a weight-average molecular weight of more than field. 10 5,000,000 are used, and that since full control of the reaction is difficult, and thus water-insoluble polymers which form a BACKGROUND ART molecular structure in the form of three-dimensional network are likely to be produced. For a detergent used to remove stains on ceramic products As such, conventional thickeners have exhibited insuffi Such as bathroom tiles, washing stands, toilet bowls, tiles for 15 cient thickening effect or stability over time in strongly acidic interior decoration and the like, an acidic detergent compris aqueous solutions. In an attempt to enhance the thickening ing hydrochloric acid, citric acid, etc. as a cleaning compo effect of a detergent, an improvement Such as increasing the nent, a neutral detergent or a chlorine-based detergent has amount of a thickener to be added may be considered, but this been used. Conventionally, for Such detergents, studies are causes the reduction in the fluidity of liquid acidic detergents being carried out on a water-soluble thickener which works and makes it difficult for the detergent to flow out from the effectively upon being mixed into liquid detergents to Suit nozzle of a detergent container, thus making it unpleasant to ably adjust the Viscosity, so that when the liquid detergent is use the detergents. Further, detergents are produced to com applied on the vertical side of a tile or on a toilet bowl, the prise large amounts of organic materials, which is environ liquid detergent flows down on the cleaning Surface slowly. mentally not preferable. Also, on the other hand, when the For instance, among the liquid acidic detergents for clean 25 improvement in the fluidity of acidic detergents is made by ing tiles which use Sulfamic acid and glycolic acid in combi adjusting the amount of the thickener to be added, there is a nation as acidic base materials, an acidic detergent compris problem in that a Sufficient anti-dripping property of the ing polyvinyl alcohol as a thickener and urea as a stabilizer is detergent on the ceramic Surfaces and the like cannot be disclosed (JP-A-53-46302). This detergent comprises sul obtained. famic acid instead of hydrochloric acid as an acidic base 30 material in consideration of safety. However, since Sulfamic DISCLOSURE OF THE INVENTION acid alone is less effective than hydrochloric acid in the clean ing effect, the detergent uses glycolic acid as an acidic adju The inventors have conducted extensive studies to solve the vant. Further, polyvinyl alcohol as a thickener is likely to above-mentioned problems and have found that water result in reducing viscosity due to the occurrence of gelation 35 soluble thickeners consisting of certain copolymers which when used at low temperatures in winter, etc. show excellent thickening effect and stability even in a Further, detergents which comprise a mineral acid such as strongly acidic aqueous Solution can solve the problems, thus hydrochloric acid, a halogen Scavenger, a Surfactant and a completing the invention. thickener as essential components, and which comprise Xan Thus, the present invention is characterized by the follow than gum, cationized cellulose, polyethylene glycol, polyvi 40 ing. nyl pyrrolidone or polyacrylamide methylpropanesulfonic (1) A first invention is a water-soluble thickener compris acid as a thickener are disclosed (for example, in JP-A-9- ing a water-soluble copolymer having a weight-average 143498 or JP-A4-209700). Among these, a homopolymer of molecular weight of 6,000,000 or higher obtainable by poly polyacrylamide methylpropanesulfonic acid shows a thick merizing a monomer mixture which comprises 2-acrylamido ening effect to the extent that may be obtained by 10% hydro 45 2-methylpropanesulfonic acid and/or a salt thereof and chloric acid, but it is not satisfactory because it cannot satisfy acrylic acid and/or a salt thereofas essential components and both the fluidity and the anti-dripping property at the same optionally other copolymerizable monomer components, time. None of these thickeners have a sufficient thickening wherein 2-acrylamido-2-methylpropanesulfonic acid and/ effect under acidic conditions and satisfactory stability over or a salt thereof represents 20 mol % or more of all the time. Thus, reports have been made upon studies on using a 50 OOCS. copolymer instead of a homopolymer as a water-soluble (2) The second invention is a liquid acidic detergent con thickener. sisting of an aqueous solution which comprises the above For instance, reports have been made that a water-soluble mentioned water-soluble thickener as the essential compo thickener comprising a copolymer comprising (meth)acryla nent, and a mineral acid and/or an organic acid. mide alkylsulfonic acid and an alkyl group-containing unsat 55 urated monomer (JP-A-10-279636) and a water-soluble BRIEF DESCRIPTION OF THE DRAWINGS thickener comprising a crosslinked copolymer obtained by the polymerization of-(meth)acryl amide alkylsulfonic acid FIG. 1 is a schematic diagram of the equipment used for and a crosslinking monomer with (meth)acrylic acid, dialkyl measuring the fluidity of a liquid acidic detergent. acrylamide, acryloylmorpholine, hydroxyethyl methacry 60 FIG. 2 is a schematic diagram of the equipment used for late, vinyl pyrrolidone or the like, causea less viscosity reduc measuring the dripping rate of a liquid acidic detergent.