JP2014129429A - Acidic reducible composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acidic reducible composition and an acidic reducible detergent composition each including oxalic acid and excellent in terms of low-temperature stability and a method for enhancing the solubility of oxalic acid with water.SOLUTION: The solubility of oxalic acid with water is enhanced by virtue of the coexistence of polyvinyl alcohol with the oxalic acid. An oxalic acid-containing acidic reducible composition or acidic reducible detergent composition excellent in terms of low-temperature stability, furthermore, is provided by exploiting this characteristic.

Description

  The present invention relates to an acidic reducing composition and a method for enhancing the solubility of oxalic acid in water.

Usually, as the cleaning agent with reducibility, one or two reducing treatment agents such as acidic ammonium fluoride, ammonium thioglycolate, oxalic acid, hydrochloric acid, dilute sulfuric acid, sulfamic acid, citric acid and glycolic acid are used. Cleaning agents containing the above in combination are known (Patent Documents 1 to 4). For example, with a reducing treatment agent, the oxide film of the copper product that has become copper oxide can be reduced to remove the dirt component to restore the original metallic luster, or the oxide film of the rusted iron product that has become iron oxide can be reduced. It is possible to restore the original metallic luster by dissolving the dirt component.
However, for example, although acidic ammonium fluoride has a high reactivity to an oxide film, there is a problem that the influence on the human body is large. Hydrochloric acid has a large pungent odor, and metals such as steel and aluminum are subject to corrosion. Since dilute sulfuric acid generates hydrogen in steels, danger is pointed out when used in a closed system. Citric acid and glycolic acid have little influence on the human body, but the reaction to the oxide film is slow, and it is necessary to increase the blending amount in order to increase the reactivity. Thioglycolic acid has problems such as significant unpleasant odor. In recent years, oxalic acid as a main component has been proposed as one that has little influence on odor and human body and is excellent in reducibility.

  However, since oxalic acid has a low solubility at a low temperature of 3.5 g at 0 ° C. with respect to 100 g of water (Non-patent Document 1), oxalic acid is recrystallized in the cold season and precipitates, resulting in reduced reducibility. There was a problem of low temperature stability, which was reduced.

JP 2006-249488 A JP 2010-024366 A JP 2010-065239 A JP 2011-032495 A

Iwanami Physical and Chemical Dictionary 3rd edition (Publisher: Iwanami Shoten Co., Ltd., page 611)

  The present invention has an acidic reducing composition and an acidic detergent composition containing oxalic acid excellent in low-temperature stability, and has a stable reducing performance even in the cold season by enhancing the solubility of oxalic acid in water. It is to provide a method.

  As a result of intensive studies to achieve the above problems, the present inventor exceeds the solubility of oxalic acid in water described in Non-Patent Document 1 by blending polyvinyl alcohol into an aqueous solution containing oxalic acid. Nevertheless, it was found that oxalic acid crystals did not precipitate. What was particularly surprising was that the effect was exhibited in a region where the blending amount of the polyvinyl alcohol was very small. The present invention has been completed based on this finding.

That is, the present invention provides the following inventions.
(Item 1) An acidic reducing composition containing oxalic acid and polyvinyl alcohol.
(Item 2) The acid-reducing composition according to item 1, wherein the acid-reducing composition contains 0.01 to 15% by weight of oxalic acid and 0.01 to 15% by weight of polyvinyl alcohol.
(Item 3) The acidic reducing composition according to Item 1 or Item 2, wherein the ratio of oxalic acid to polyvinyl alcohol is in the range of 0.001 to 5 parts by weight with respect to 1 part by weight of oxalic acid.
(Item 4) The acidic reducible composition according to any one of the above items 1 to 3, wherein the acidic reducible composition has a pH of 0.1 to 4.0.
(Item 5) The acidic reducing agent composition according to any one of Items 1 to 4, wherein the polyvinyl alcohol is obtained by saponifying polyvinyl acetate.
(Item 6) The acidic reducing composition according to Item 5, wherein the saponification degree of polyvinyl alcohol is 60 to 100 mol%.
(Item 7) An acidic reducing detergent composition, wherein the acidic reducing composition according to any one of Items 1 to 6 contains a surfactant.
(Item 8) The acidic reducing detergent composition according to Item 7, for removing rust from a stainless steel exterior material or an aluminum exterior material.
(Item 9) The acidic reducing detergent composition according to Item 7, for removing rust on the outer plate of the vehicle.
(Item 10) The acidic reducing detergent composition according to Item 9, wherein the vehicle is a railway vehicle.
(Item 11) Further, it contains a hard water resistant component, a chelating agent, a pH adjuster, a fragrance, a deodorant, a disinfectant, an antiseptic, a viscosity adjuster, a solvent, a builder, an antifoaming agent, or an antioxidant Item 11. The acidic reducing detergent composition according to any one of Items 7 to 10.
(Item 12) A method for increasing the solubility of oxalic acid in water, wherein polyvinyl alcohol is allowed to coexist with oxalic acid.
(Item 13) The method according to Item 12, wherein the amount of polyvinyl alcohol used is in the range of 0.001 to 5 parts by weight per 1 part by weight of oxalic acid.

Since the acidic reducing composition and the acidic reducing detergent composition of the present invention are excellent in low-temperature stability, reduction in reducing ability can be suppressed in cold regions. And since there is little usage-amount of polyvinyl alcohol, reduction of a load can be anticipated at the time of waste liquid processing.
Further, the method for enhancing the solubility of oxalic acid in water according to the present invention is a very simple method, and can enhance the solubility of oxalic acid in water at low temperatures, thereby improving the low-temperature stability in various applications. Can be expected.

  The acidic reducing composition of the present invention is a composition comprising oxalic acid and polyvinyl alcohol.

  As the oxalic acid according to the present invention, oxalic acid (anhydrous), oxalic acid / dihydrate, etc. can be used, and there is no particular limitation, and those manufactured by known methods, commercially available products, reagents, etc. Can be used. Major suppliers include Mitsubishi Gas Chemical Co., Ltd. and Ube Industries, Ltd.

As the polyvinyl alcohol according to the present invention, those produced by a known method, commercially available products, reagents and the like can be used. Polyvinyl alcohol is generally produced by saponifying polyvinyl acetate. The polyvinyl alcohol may be a copolymer (modified polyvinyl alcohol) with a component capable of copolymerizing polyvinyl acetate, as long as the effects of the present invention are exhibited.
Polyvinyl alcohol is roughly classified into a fully saponified type and a partially saponified type depending on the degree of saponification (degree of saponification). In the present invention, it is most preferable to use completely saponified polyvinyl alcohol. When partially saponified polyvinyl alcohol is used, a degree of saponification of 60 to 100 mol%, more preferably 90 to 100 mol%, particularly preferably 98 to 100 mol% is recommended.
The polymerization degree of polyvinyl alcohol is preferably 300 to 5000, more preferably 500 to 3500.
Major suppliers include Kuraray Co., Ltd., Nippon Synthetic Chemical Industry Co., Ltd., Nippon Vinegar Pover Co., Ltd., etc.

The composition ratio of oxalic acid and polyvinyl alcohol contained in the acidic reducing composition of the present invention is preferably 0.01 to 15% by weight, more preferably oxalic acid content as the composition ratio in the acidic reducing composition. 0.5 to 10% by weight is recommended, and the content of polyvinyl alcohol is preferably 0.01 to 15% by weight, more preferably 0.05 to 10% by weight, and particularly preferably 0.1 to 6% by weight. Is recommended.
The ratio of oxalic acid to polyvinyl alcohol is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 3 parts by weight, with respect to 1 part by weight of oxalic acid.
Within these recommended ranges, the effects of the present invention are more stably exhibited.

  The acidic reducing composition of the present invention essentially contains water. Examples of the water include distilled water, ion-exchanged water, tap water, and groundwater, but preferably distilled water or ion-exchanged water is recommended. In the case of using tap water and groundwater, it is recommended that the hardness is 200 ppm or less, more preferably 50 ppm or less.

  The pH of the acidic reducing composition of the present invention is preferably 0.1 to 4.0, more preferably 0.3 to 3.0, from the viewpoint of the removal rate and removal time of metal oxide film and rust. Recommended.

The acidic reducing detergent composition according to the present invention is obtained by blending a surfactant as an essential component with an acidic reducing composition.
The blending amount of the surfactant is preferably 0.05 to 15% by weight, more preferably 0.1 to 10% by weight, as a composition ratio in the acidic reducing detergent composition.

  As the surfactant, preferably a nonionic surfactant or an anionic surfactant is recommended. More specifically, as the nonionic surfactant, polyoxyalkylene alkyl ether, polyoxyalkylene alkenyl ether, polyoxyethylene polyoxypropylene copolymer, polyoxyethylene alkylamide, polyoxyethylene alkylphenyl Examples include ethers. Among these, a polyoxyalkylene compound represented by the following general formula (1) is recommended.

〔式中、Ｒ^１は、炭素数８〜２２の直鎖状若しくは分岐鎖状の脂肪族基又は一般式(２)

［式中、Ｒ^３は、炭素数８〜１８の直鎖状若しくは分岐鎖状のアルキル基を表す。］で表されるｐ-アルキルフェニル基を表す。Ｒ^２は、エチレン基又はプロピレン基を表す。ｎは、平均付加モル数を表し、３〜１００を示す。〕
で表される。 General formula (1)

[Wherein, R ¹ represents a linear or branched aliphatic group having 8 to 22 carbon atoms, or a general formula (2)

[Wherein R ³ represents a linear or branched alkyl group having 8 to 18 carbon atoms. P-alkylphenyl group represented by the formula: R ² represents an ethylene group or a propylene group. n represents an average addition mole number and shows 3-100. ]
It is represented by

  The polyoxyalkylene compound is a compound having an aspect in which ethylene oxide and / or propylene oxide is subjected to an addition reaction with a linear or branched aliphatic alcohol or a p-alkylphenol having a linear or branched alkyl group. is there.

  Specific examples of the linear aliphatic alcohol include n-octanol, n-nonanol, n-decanol (capryl alcohol), n-undecanol, n-dodecanol (lauryl alcohol), n-tridecanol, and n-tetradecane. Decanol (myristyl alcohol), n-pentadecanol, n-hexadecanol (cetyl alcohol), n-heptadecanol, n-octadecanol (stearyl alcohol), n-nonadecanol, n-icosanol, n-henicosanol , N-docosanol, and oleyl alcohol. Among these, n-octanol, n-nonanol, n-decanol (capryl alcohol), n-undecanol, n-dodecanol (lauryl alcohol), n-tridecanol, n-tetradecanol (myristyl alcohol), n-pentadecane Nol, n-hexadecanol (cetyl alcohol), n-heptadecanol, n-octadecanol (stearyl alcohol) are preferred, especially n-decanol (capryl alcohol), n-undecanol, n-dodecanol (lauryl alcohol) N-tridecanol and n-tetradecanol (myristyl alcohol) are preferred. These can be used alone or in combination of two or more.

  Specific examples of branched aliphatic alcohols include 6-methyl-1-heptanol, 2-octanol, 3-octanol, 2-methyl-1-heptanol, 2-ethyl-1-hexanol, and 7-methyl. -1-octanol, 2-nonanol, 3-nonanol, 2-methyl-1-octanol, 3-methyl-1-octanol, 4-methyl-1-octanol, 5-methyl-1-octanol, 6-methyl-1 -Octanol, 2-ethyl-1-heptanol, 2,4-dimethyl-1-heptanol, 2,5-dimethyl-1-heptanol, 4,6-dimethyl-1-heptanol, 2,6-dimethyl-4-heptanol 3,5,5-trimethyl-1-hexanol, 2,5,5-trimethyl-1-hexanol, 8-methyl-1-nonanol, 2-decanol, 3-decanol, 2-methyl-1-nonanol, 2 -Ethyl-1-octanol 2-propyl-1-heptanol, 2,7-dimethyl-1-octanol, 2,6-dimethyl-2-octanol, 2,4-dimethyl-1-octanol, 3,7-dimethyl-1-octanol, 3, 6-dimethyl-3-octanol, 4-methyl-2-propyl-1-hexanol, 5-methyl-2-propyl-1-hexanol, 2- (1-methylethyl) -4-methyl-1-hexanol, 2 -(1-methylethyl) -5-methyl-1-hexanol, 8-methyl-2-decanol, 2,4,6-trimethyloctanol, dimethylnonanol, 10-methylundecanol, 2-ethyldecanol, 2-Methyl-3-tert-butylheptane-1-ol, 2-methyldodecanol, 10-methyl-1-dodecanol, 2,6,10-trimethylundecanol, 1,3,5,7- Tetramethyldecanol, 5-butyl-5-decanol, 13- Tiltetradecanol, 3,7-dimethyltridecanol, 13-methylpentadecanol, 5-butyl-5-dodecanol, 1.1-dimethylpentadecanol, 2-hexyldodecanol, isostearyl alcohol, 15- Methylheptadecanol, 4-methyloctadecanol, 9,13-dimethylheptadecanol, 2-octyldodecanol, 2,4,4,6,6,8,8,10,10-nonamethylundecanol 18-methylicosanol, 2-methylhenicosanol. Among these, 6-methyl-1-heptanol, 2-octanol, 3-octanol, 2-methyl-1-heptanol, 2-ethyl-1-hexanol, 7-methyl-1-octanol, 2-nonanol, 3- Nonanol, 2-methyl-1-octanol, 3-methyl-1-octanol, 4-methyl-1-octanol, 5-methyl-1-octanol, 6-methyl-1-octanol, 2-ethyl-1-heptanol, 2,4-dimethyl-1-heptanol, 2,5-dimethyl-1-heptanol, 4,6-dimethyl-1-heptanol, 2,6-dimethyl-4-heptanol, 3,5,5-trimethyl-1- Hexanol, 2,5,5-trimethyl-1-hexanol, 8-methyl-1-nonanol, 2-decanol, 3-decanol, 2-methyl-1-nonanol, 2-ethyl-1-octanol, 2-propyl- 1-heptanol, 2, -Dimethyl-1-octanol, 2,6-dimethyl-2-octanol, 2,4-dimethyl-1-octanol, 3,7-dimethyl-1-octanol, 3,6-dimethyl-3-octanol, 4-methyl -2-propyl-1-hexanol, 5-methyl-2-propyl-1-hexanol, 2- (1-methylethyl) -4-methyl-1-hexanol, 2- (1-methylethyl) -5-methyl -1-hexanol, 8-methyl-2-decanol, 2,4,6-trimethyloctanol, dimethylnonanol, 10-methylundecanol, 2-ethyldecanol, 2-methyl-3-tert-butylheptane- 1-ol, 2-methyldodecanol, 10-methyl-1-dodecanol, 2,6,10-trimethylundecanol, 1,3,5,7-tetramethyldecanol, 5-butyl-5- Decanol, 13-methyltetradecanol, 3,7-dimethyl Tiltridecanol, 13-methylpentadecanol, 5-butyl-5-dodecanol, 1.1-dimethylpentadecanol, 2-hexyldodecanol, isostearyl alcohol, 15-methylheptadecanol are preferred, especially 8 -Methyl-1-nonanol, 2-decanol, 3-decanol, 2-methyl-1-nonanol, 2-ethyl-1-octanol, 2-propyl-1-heptanol, 2,7-dimethyl-1-octanol, 2, , 6-Dimethyl-2-octanol, 2,4-Dimethyl-1-octanol, 3,7-Dimethyl-1-octanol, 3,6-Dimethyl-3-octanol, 4-Methyl-2-propyl-1-hexanol 5-methyl-2-propyl-1-hexanol, 2- (1-methylethyl) -4-methyl-1-hexanol, 2- (1-methylethyl) -5-methyl-1-hexanol, 8-methyl -2-Deca 2,2,6-trimethyloctanol, dimethylnonanol, 10-methylundecanol, 2-ethyldecanol, 2-methyl-3-tert-butylheptane-1-ol, 2-methyldodeca Nord, 10-methyl-1-dodecanol, 2,6,10-trimethylundecanol and 1,3,5,7-tetramethyldecanol are preferred. These can be used alone or in combination of two or more.

  Specific examples of the p-alkylphenol include ethylphenol, propylphenol, butylphenol, pentylphenol, amylphenol, hexylphenol, heptylphenol, octylphenol, nonylphenol, decylphenol, dodecylphenol, undecylphenol, tridecylphenol, Tetradecylphenol is exemplified. Among these, p-alkylphenol having 6 to 12 carbon atoms is preferable, and octylphenol and nonylphenol are particularly preferable. These can be used alone or in combination of two or more.

  As the linear or branched aliphatic alcohol or the p-alkylphenol having a linear or branched alkyl group, commercially available products, reagents, those prepared by a known synthesis method, and the like can be used.

  The said polyoxyalkylene compound can use a commercial item, a reagent, what was manufactured with the well-known synthesis method, etc.

  A method for producing the polyoxyalkylene compound is not particularly limited, and conventionally known methods can be widely used. For example, it can be easily obtained by reacting an aliphatic alcohol such as isodecyl alcohol, decanol, lauryl alcohol, nonylphenol or p-alkylphenol with ethylene oxide or propylene oxide in the presence of a catalyst. The obtained polyoxyalkylene compound usually has a distribution of the number of added moles and can be used as it is, but can also be used after being separated into a desired number of added moles by a separation operation such as precision distillation.

  N described in the general formula (1) represents the average number of moles of addition of ethylene oxide and / or propylene oxide subjected to addition reaction with an aliphatic alcohol or p-alkylphenol. Specifically, n is preferably in the range of 3 to 100, more preferably in the range of 4 to 80, and particularly preferably in the range of 5 to 60.

  The HLB of the polyoxyalkylene compound is calculated by the Griffin method. The HLB is preferably in the range of 10-18, more preferably in the range of 11-17, particularly preferably in the range of 12-15.

  Examples of the anionic surfactant include alkylbenzene sulfonic acid and its salt, α-olefin sulfonic acid and its salt, alkane sulfonic acid and its salt, polyoxyalkylene alkenyl ether sulfate, polyoxyethylene alkyl sulfate, alkyl sulfate, alkyl Examples thereof include sulfonic acid derivatives such as diphenyldisulfonic acid and its salt, polyoxyethylene alkylphenyl ether sulfuric acid and its salt, and the like.

  The form of the acidic reducing detergent composition of the present invention can be appropriately selected depending on the purpose even in a liquid, high-viscosity or gel form, but is usually used in a liquid form.

As a method of using the acidic reducing detergent composition of the present invention, a method that has been used so far for the purpose of removing a metal oxide film or rust can be appropriately selected and employed.
As a procedure, it is necessary to first determine the oxalic acid concentration. If the metal oxide film or rust condition is severe, it is recommended to use it in a mode with relatively high oxalic acid concentration, and it should be diluted with water as appropriate depending on the metal oxide film or rust condition. it can. More specifically, when an acidic reducing detergent composition having an oxalic acid concentration of 10% is used for an object to be cleaned whose metal oxide film or rust state is not severe, 50 to 100 at the time of mechanical cleaning. It is recommended to dilute to about 2 times, and it is recommended to dilute to about 2 to 20 times when washing by hand. In using the acidic reducing detergent composition of the present invention, it is desirable to appropriately select the use conditions such as the dilution ratio, the washing temperature, the washing time, and the washing method in consideration of the influence on the material. .
As for the washing operation, in the same way as using ordinary detergents, a diluted or undiluted acidic reducing detergent composition is applied or sprayed on the object to be washed, and a cloth or sponge is used for wiping or brushing. Examples thereof include brushing and mechanical cleaning using a mechanical device. If the contamination is very severe, immerse the object to be cleaned in the acidic reducing detergent composition or apply a gel-like acidic reducing detergent composition to the object to be cleaned. However, examples of the method include washing by hand wiping or brushing with a cloth or sponge after leaving for about 10 minutes to several hours. The cleaning operation is completed by rinsing the object to be cleaned and then rinsing the object to be cleaned with water. As water used for rinsing, distilled water, ion-exchanged water, tap water, underground water and the like can be appropriately selected and used. Tap water and groundwater preferably have a hardness of 200 ppm or less, more preferably 50 ppm or less.

  The acidic reducing detergent composition of the present invention has a hard water-resistant component, a chelating agent, a pH adjuster, a fragrance, a deodorant, a disinfectant, an antiseptic, and a viscosity adjuster as long as the effects of the present invention are exhibited. Various additives such as a solvent, a builder, an antifoaming agent, a reducing component (rust removing component) other than oxalic acid, and an antioxidant can be blended by appropriately adjusting the blending amount according to the desired purpose. .

Examples of the hard water-resistant component include sulfamic acid and its salt, methanesulfonic acid and its salt, isethionic acid and its salt, alkylbenzenesulfonic acid and its salt, α-olefin sulfonic acid and its salt, alkanesulfonic acid and its salt Sulfonic acid derivatives such as polyoxyalkylene alkenyl ether sulfate, polyoxyethylene alkyl sulfate, alkyl sulfate, alkyl diphenyl disulfonate, polyoxyethylene alkyl phenyl ether sulfate, polyacrylic acid and its salt, polymethacrylic acid and its Examples thereof include polymer derivatives such as salts, polystyrenesulfonic acid and salts thereof, acrylamide-methylpropanesulfonic acid copolymers and salts thereof, and the like.
The blending amount of the hard water-resistant component is preferably 0.1 to 5% by weight, more preferably 0.5 to 4% by weight as a composition ratio in the acidic reducing detergent composition.

Examples of the chelating agent include ethylenediaminetetraacetic acid, hydroxyethyliminodiacetic acid, dihydroxyethylglycine, nitrilotriacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminopentaacetic acid, triethylenetetraaminohexaacetic acid, L-glutamic acid diacetic acid, L -Aspartic acid-N, N-diacetic acid, 2-hydroxyethyliminodiacetic acid, gluconate, 3-hydroxy-2,2-iminodisuccinic acid, hydroxyethylidene diphosphonic acid, nitrilotris (methylenephosphonic acid), phosphombutane Examples of tricarboxylic acids and salts of alkali metals, ammonium, etc., are used as part or all of these acids.
The blending amount of the chelating agent is preferably from 0.01 to 3% by weight, preferably from 0.05 to 2% by weight, as a composition ratio in the acidic reducing detergent composition.

Examples of pH adjusting agents include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, alkanolamines such as N, N-bis (2-hydroxyethyl) -N-cyclohexylamine, 2-Amino-1-butanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3- Examples include amino alcohols such as propanediol, alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, and butylamine.
The blending amount of the pH adjuster is preferably 0.01 to 15% by weight, more preferably 0.1 to 10% by weight, as the composition ratio in the acidic reducing detergent composition.

Examples of the fragrances include natural fragrances, synthetic fragrances and food fragrances. Natural flavors include acacia oil, anise seed oil, abies oil, apsin oil, almond bitter oil, angelica oil, ambrette seed oil, inondo oil, ylang ylang oil, iris oil, seaweed oil, winter green, warmwood oil , Estragon oil, Elemi oil, Oak moss oil, Ocotia oil, Onion oil, Opopanax oil, Dutch seri oil, Oris oil, Olivenum oil, Orange oil, Cassia oil (Katsura oil, Cinnamon oil), Cassie oil, Kananga oil, Chamomile oil , Camomile oil, gayakwood oil, kayapte oil, mustard oil, columnus oil, garlic oil, cardamom oil, galvanum oil, yellow pepper oil, caraway oil, bitter oil, cumin oil, clary sage oil, grapefruit oil, clove oil , Laurel leaf oil, cilantro oil, costas oil, co Der oil, sandalwood oil, cedarwood oil, citronella oil, jasmine oil, ginger oil, camphor root oil, gill oil, ginger oil, ginger class oil, cinnamon oil, sacred oil, star anise oil, spike oil, spearmint oil, sage Oil, geranium oil, thyme oil, tangerine oil, tuberose oil, turpentine oil, narcissus oil, nutmeg oil, sagebrush oil, garlic oil, neroli oil, pine oil, parsley oil, basil oil, birch oil, patchouli oil, peppermint oil, rose Oil, palmarosa oil, sandalwood oil, hyacinth oil, bay oil, bay leaf oil, vetiver oil, penny royal oil, henoposi oil, peppermint oil, beryla oil, melamine oil, ginger leaf oil, hop oil, porai oil, mimosa oil , Myrte oil, myrtle oil, mill oil, mint oil, mace oil, eucalyptus oil, la Palm oil, lavandin oil, lavender oil, Riseakyubeba oil, linaloe oil, lemon grass oil, lemon oil, rosewood oil, rosemary oil, rose oil, lovage oil, and the like. Synthetic fragrances include α-pinene, β-pinene, camphene, d-limonene, dipentene, terpinolene, alloocimene, osimene, p-cymene, β-caryophyllene, green leaf alcohol, 3-octenol, 9-decenol, linalool, geraniol, Nerol, citronellol, l-citronellol, dimethyloctanol, hydroxycitronellol, tetrahydrolinalol, lavandulol, allocimerol, myrsenol, α-pineol, terpine hydrate, l-menthol, borneol, isopulegol, nopol, bornylmethoxycyclohexanol, melolidol , Farnesol, santalol, iso y super, sandalol, cedrol, vetiverol, patchouli alcohol, benzyl alcohol, β-phenyl alcohol, -Phenylpropyl alcohol, cinnamic alcohol, anis alcohol, α-amyl cinnamic alcohol, dimethylbenzylcarbinol, methylphenylcarbinol, β-phenylethyldimethylcarbinol, dimethylphenylcarbinol, β-phenylethylmethylethylcarbinol , Phenoxyethyl alcohol, phenyl glycol, tert-butylcyclohexanol, anisole, p-acetylanisole, diphenyl oxide, dimethylhydroquinone, p-cresol methyl ether, anethole, dihydroanethole, thymol, carvacrol, eugenol, isoeugenol, methyl eugenol , Methylisoeugenol, benzylisoeugenol, safrole, isosafrole, β-naphtholme Ether, β-naphthol ethyl ether, banitrop, n-heptylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, n-undecylaldehyde, undecylenealdehyde, dodecylaldehyde, methylnonylacetaldehyde, n-tridecyl Aldehyde, n-tetradecylaldehyde, n-hexadecylaldehyde, nonadienal, citral, citronellal, hydroxycitronellal, perilaldehyde, benzaldehyde, phenylacetaldehyde, phenylpropylaldehyde, cinnamaldehyde, α-amylcinnamic aldehyde, α- Hexylcinnamic aldehyde, anisaldehyde, cuminaldehyde, heliotropin, helional, cyclamenaldehyde, p- ert-α-methylhydrocinnamic aldehyde, salicylaldehyde, hydrotropaldehyde, vanillin, ethyl vanillin, γ-undecalactone, ethyl methylphenylglycidate, γ-nonyllactone, p-methyl-β-phenylglycid Ethyl acetate, allyl caproate, allyl caprylate, lyral, mylacaldehyde, citronellyloxyacetaldehyde, citral dimethyl acetal, citral diethyl acetal, phenylacetaldehyde dimethyl acetal, methyl-n-amyl ketone, ethyl-n-amyl ketone, methyl-n -Hexylketone, methyl-n-nonylketone, methylheptene, diacetyl, l-carvone, d-carvone, menthone, d-pulegone, piperitone, camphor, methylcedrin, acetophenone, p-methyl Cetophenone, p-methoxyacetophenone, benzophenone, benzylideneacetone, methyl naphthyl ketone, yonon, damascon, damasenone, methyl ionone, ilon, maltol, ethyl maltol, hydroxyfuran, neron, hydroxyphenylbutanone, anisylacetone, jasmon, hydrojasmon, nootkaton, Muscone, dibeton, cyclopentadecane, cyclohexadecenone, cyclopentadecanolide, ambretlide, cyclohexadecanolide, ethylene brushate, ethylenedodecanedioate, 12-oxahexadecanolide, 11-oxahexadecanolide 10-oxahexadecanolide, musk xylol, musk ketone, musk amblet, musk tibetan, mosken, phantolide, selenium Stridolide, traseolide, versalide, tonalide, galaxolide, rose oxide, oxide ketone, 3,3,6-trimethyl-6-vinyltetrahydropyran, dihydromethylpentenylpyran, linalool oxide, cineol, bicyclodihydrohomofarnesyl oxide, phenylethyl isoamyl ether , Geranyl formate, benzyl formate, phenyl formate, ethyl acetate, isoamyl acetate, citronellyl acetate, geranyl acetate, linalyl acetate, menthyl acetate, bornyl acetate, isobornyl acetate, terpinyl acetate, benzyl acetate, phenylethyl acetate, methyl phenyl carvinyl acetate, Cinnamyl acetate, Anisyl acetate, Paracresyl acetate, Isoeugenol acetate, Milcenyl acetate, Tertiary butyl cyclohexyl acetate Dihydroterpi , Ethyl propionate, isoamyl propionate, citronellyl propionate, linalyl propionate, geranyl propionate, terpinyl propionate, benzyl propionate, cinnamyl propionate, ethyl butyrate, isoamyl butyrate, geranyl butyrate, linalyl butyrate, linalyl isobutyrate, Citronellyl butyrate, citronellyl isobutyrate, benzyl isobutyrate, n-propyl isovalerate, isoamyl isovalerate, geranyl isovalerate, benzyl isovalerate, cinnamyl isovalerate, methyl heptine carboxylate, isoamyl heptine carboxylate, Ethyl heptine carboxylate, isoamyl pyruvate, methyl octynecarboxylate, ethyl acetoacetate, ethyl levulinate, methyl β-methylmercaptopropionate, ethyl benzoate, methyl benzoate, Isobutyl benzoate, isoamyl benzoate, geranyl benzoate, linalyl benzoate, benzyl benzoate, methyl phenylacetate, ethyl phenylacetate, isobutyl phenylacetate, isoamyl phenylacetate, geranyl phenylacetate, benzyl phenylacetate, ethyl cinnamate, cinnamon Benzyl acid, cinnamyl cinnamate, dimethyl phthalate, diethyl phthalate, methyl salicylate, ethyl salicylate, isobutyl salicylate, isoamyl salicylate, allyl salicylate, benzyl salicylate, phenylethyl salicylate, methyl anisate, ethyl anisate, methyl anthranilate, methyl Methyl anthranilate, ethyl anthranilate, methyl dihydrojasmonate, methyl jasmonate, synthetic oak moss, benzoic acid, cinnamic acid, phenylacetic acid, hydrocinnamic acid Coumarin, indole, skatole, 2-methyltetrahydroquinoline, 6-methylquinoline, 6-methyltetrahydroquinoline, 7-methylquinoline, isobutylquinoline, 6-isopropylquinoline, tetramethylpyrazine, acetylpyrrole, geranyltolyl, bromosteel, acetic acid Examples include trichloromethylphenylcarbinyl and furfuryl mercaptan.
The blending amount of the fragrance is preferably 0.01 to 2% by weight, more preferably 0.05 to 0.5% by weight, as the composition ratio in the acidic reducing detergent composition.

Examples of the deodorant include plant essential oils, plant extracts, chemical substances such as chlorine dioxide, and more specifically, rose oil, lily of the valley oil, valerian oil, jasmine oil, lemon oil, gardenia oil, mint oil Fragrances such as violet oil, masking agents such as cinnamic aldehyde, vanillin, heliotropin, coumarin, carvone, canafer, and bonol, turpentine oil, clove oil, cinnamon oil, cedar oil, orange oil, lemon oil, orange peel oil And the like.
The blending amount of the deodorant is preferably 0.01 to 2% by weight, more preferably 0.05 to 0.5% by weight, as a composition ratio in the acidic reducing detergent composition.

Examples of the disinfectant include amphoteric surfactants, cationic surfactants, and active soaps.
The mixing amount of the disinfectant is preferably 0.005 to 1% by weight, more preferably 0.01 to 0.5% by weight as the composition ratio in the acidic reducing detergent composition.

Examples of preservatives include benzoic acid, salicylic acid, dehydroacetic acid, sodium dehydroacetate, sorbic acid, boric acid, chlorxylenol, resorcin, paraoxybenzoic acid ester, phenoxyethanol, thymol, hinokitile, thioxolone, benzalkonium chloride, benzoic chloride Examples include tonium, lauryl di (aminoethyl) glycine, chlorhexidine gluconate, chlorobutanol and the like.
The preservative content is preferably 0.005 to 2% by weight, more preferably 0.01 to 1% by weight, as the composition ratio in the acidic reducing detergent composition.

Examples of the viscosity modifier include polyether type thickeners such as polyoxyethylene (average number of added moles: 60) cetostearyl hydroxymyristyl ether, polyoxyethylene (60) cetyl stearyl diether, and polyethylene glycol distearate (150). , Polyetherester type thickeners such as polyoxyethylene tetrastearate (150) pentaerythrit, polyoxyethylene triisostearate (160) sorbitan, polyoxyethylene (120) methyl dioleate, hydroxyethyl cellulose, hydroxypropyl Examples include water-soluble polymer thickeners such as methylcellulose, sodium polyacrylate, xanthan gum, and inorganic salt thickeners such as sodium sulfate and sodium chloride.
The blending amount of the viscosity modifier is preferably 0.01 to 5% by weight, more preferably 0.1 to 3% by weight, as the composition ratio in the acidic reducing detergent composition.

Examples of the solvent include alcohol solvents, cellosolve solvents, hydrocarbon solvents, aqueous ammonia, glycols, glycol ethers, and the like. Alcohol solvents include alcohol solvents such as ethanol and isopropyl alcohol, cellosolv solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and phenyl cellosolve, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, Tylene glycol monohexyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol mono Low glycol glycol solvents such as butyl ether, 3-methoxy-3-methyl-1-butanol, lactam solvents such as N-methyl-2-pyrrolidone, lactone solvents such as γ-butyrolactone, glycerol, xylitol, sorbitol, etc. Molecular polyhydric alcohol solvents, glycol solvents such as ethylene glycol, propylene glycol, butylene glycol Etc. are exemplified.
The blending amount of the solvent is preferably 0.1 to 25% by weight, more preferably 1 to 15% by weight, as the composition ratio in the acidic reducing detergent composition.

Examples of builders include organic builders and inorganic builders. Examples of the organic builder include alkanolamines exemplified for the pH adjuster. Examples of the inorganic builder include carbonates such as sodium hydroxide, potassium hydroxide, sodium sulfate and sodium carbonate.
The builder blending amount is preferably 0.1 to 8% by weight, more preferably 0.5 to 7% by weight as the composition ratio in the acidic reducing detergent composition.

Examples of antifoaming agents include oil-based, oil-compound-type, solution-type, emulsion-type, self-emulsification-type silicone-type antifoaming agents, surfactants, polyethers, organic-type antifoaming agents such as higher alcohols, and the like. The
The blending amount of the antifoaming agent is preferably 0.001 to 0.5% by weight, more preferably 0.003 to 0.1% by weight, as the composition ratio in the acidic reducing detergent composition.

As reducing components (rust removing components) other than oxalic acid, malic acid, citric acid, tartaric acid, glycolic acid, glyceric acid, lactic acid, methanesulfonic acid, sulfamic acid, isethionic acid, itaconic acid, succinic acid, thioglycolic acid, Examples thereof include thiomalic acid, butanetetracarboxylic acid, propanetricarboxylic acid, toluenesulfonic acid, xylenesulfonic acid, formic acid, acetic acid, and salts thereof.
The blending amount of the reducing component other than oxalic acid is preferably 0.05 to 10% by weight, more preferably 0.1 to 7% by weight as the composition ratio in the acidic reducing detergent composition.

Antioxidants include, for example, nordihydroguaiaretic acid, guaiac fat, propyl gallate, butylhydroxyanisole, dibutylhydroxytoluene, α-tocopherol (vitamin E), sodium sulfite, potassium sulfite, sodium pyrosulfite, pyro Sulfites such as potassium sulfite, hyposulfites such as sodium hyposulfite, potassium hyposulfite, isoascorbic acid, ascorbic acid, sodium ascorbate, ascorbate such as potassium ascorbate, thiosorbitol, cysteine hydrochloride, sodium thiosulfate, Thiosulfates such as potassium thiosulfate, gallic acid, sodium gallate, pyrogallol, tannic acid, persimmon astringent, glyoxal, tartaric acid, hydroquinone, longarit, salicylic acid, gluconic acid, pyrocatechol , 3-hydroxybutyric acid, propionic acid, phthalic acid, isophthalic acid, 3-hydroxy salicylic acid, 3,5-dihydroxy salicylic acid, succinic acid, sulfosalicylic acid, and triethylene glycol acid.
The blending amount of the antioxidant is preferably 0.1 to 5% by weight, particularly preferably 0.2 to 3% by weight, as a composition ratio in the acidic reducing detergent composition.

  The acidic reducing detergent composition of the present invention has good low-temperature stability even in the cold season and high rust removal properties. Because it has such characteristics, it is suitable for removing rust or adhering rust on painted or metal surfaces such as stainless steel exterior materials, stainless steel sinks, railcar outer plates (stainless steel vehicles, aluminum vehicles, etc.) Can be used. In particular, it is suitable as a rust removal cleaner for removing rust on the coated surface or metal surface of the railcar outer plate or the like, or the attached rust, which needs to be quickly removed.

The method for enhancing the solubility of oxalic acid in water according to the present invention can be easily achieved by allowing polyvinyl alcohol to coexist with oxalic acid. At this time, the usage amount of polyvinyl alcohol is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 3 parts by weight with respect to 1 part by weight of oxalic acid. Within this recommended range, the effects of the present invention are more stably exhibited.
By this method, the amount of oxalic acid solubilized in water at the same temperature can be increased. In other words, the storage stability at low temperatures can be enhanced by this method.
According to Non-Patent Document 1, the solubility (g / 100 g) of oxalic acid in water is 3.5 (0 ° C.), 9.5 (20 ° C.), 21.5 (40 ° C.), 61.1. (60 ° C.).

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, physical properties and chemical properties in each example were evaluated by the following methods.

[Low temperature stability (soluble)]
Samples for evaluation were stored at 0 ° C. and −5 ° C. for 30 days to evaluate low-temperature stability (soluble).
The evaluation method visually observed the external appearance of the sample for evaluation, and judged by the presence or absence of precipitation (oxalic acid). When there is no precipitate, it indicates that oxalic acid is soluble in water at the storage temperature, and it is evaluated that the solubility is increased when there is a difference in the precipitate as compared with the comparative example. In such an evaluation, it means that the low temperature stability has been improved.

[Derusting property]
Material and reagent test piece: Stainless steel SUS-304 6 × 8cm
Iron powder (manufactured by Nacalai Tesque)
Sodium chloride (Nacalai Tesque)
Nonionic surfactant: polyoxyethylene (average number of moles added: 8) polyoxypropylene (average number of moles added: 4) polyoxyethylene (average number of moles added: 4) oleyl ether (trade name; Ricanone EP-200, New Nippon Rika Co., Ltd.)
Kimwipe (Nippon Paper Crecia Co., Ltd.)
Test piece preparation method The test piece was thoroughly washed with an alkaline detergent, washed with acetone, dried, and weighed (A) to the fourth decimal place. Next, the test piece was covered with Kimwipe moistened with an aqueous solution containing sodium chloride (5% by weight) and nonionic surfactant (1% by weight) to prevent air from entering, and 0.3 to 0.4 g of iron powder ( (100 mesh) was sprinkled, and the mixture was made as uniform as possible using a micro spatula, and sprayed with an aqueous solution containing sodium chloride (5% by weight) and nonionic surfactant (1% by weight), and homogenized again. Thereafter, it was left at room temperature for 72 hours to rust. Kimwipe was removed from the rusted test piece, washed with water, air-dried for 24 hours, and weighed (B) to the fourth digit of the decimal point.
Preparation of test solution The sample for evaluation was stored at −5 ° C. for 30 days, and the sample on which oxalic acid was deposited was filtered, and the filtrate was used as the test solution. About the sample for evaluation in which oxalic acid did not precipitate, it was used as a test solution as it was.
Test method Dilute the test solution 50 times with tap water, immerse the test piece in the diluted test solution at 25 ° C for 40 minutes, rinse with running water for 1 minute, air dry for 12 hours, and weigh to the fourth decimal place (C) did. This test was performed twice, the rust removal rate was calculated from the following formula, and the average value of these values was defined as the rust removal rate of the acidic reducing detergent composition.
Rust removal rate (%) = {(B)-(C)} × 100 / {(B)-(A)}

[Examples 1-6, Comparative Examples 1-2]
Samples for evaluation (the acidic reducing composition of the present invention or the outside of the present invention) were prepared by adding ion-exchanged water as the balance to the predetermined amount (g) of oxalic acid / dihydrate and polyvinyl alcohol listed in Table 1. Composition) was prepared. The sample for evaluation was dissolved in oxalic acid to obtain a uniform transparent state, and then stored at storage temperatures of 0 ° C. and −5 ° C. for 30 days. The evaluation results are shown in Table 1.

[Examples 7 to 11 and Comparative Examples 3 to 7]
The acidic reducing detergent composition of the present invention having a composition ratio (parts by weight) shown in Table 2 and a detergent composition outside the present invention were prepared. The evaluation results of pH, low temperature stability and rust removal rate of these compositions are shown in Table 2.

<Abbreviations of compounds, etc.>
Oxalic acid oxalic acid dihydrate: Mitsubishi Gas Chemical Co., Ltd., purity 99.5%
Polyvinyl alcohol PVA-1: Gohsenol NH-18 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., fully saponified type, viscosity 25-30 mPa · s)
PVA-2: Gohsenol NH-11 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., complete saponification type, viscosity 13-15 mPa · s)
Surfactant dodecylbenzene sulfonic acid: Neoperex GS (trade name, manufactured by Kao Corporation)
Sodium dodecyl diphenyl ether disulfonate: eleminol MON-2 (trade name, manufactured by Sanyo Chemical Industries, Ltd.)
Polyoxyalkylene alkyl ether (A): polyoxyethylene (average number of moles added: 10) decyl ether (trade name; Fine Surf D-1310, HLB: 14.7, manufactured by Aoki Oil & Fat Co., Ltd.)
Polyoxyalkylene alkyl ether (B): polyoxyethylene (average number of moles added: 7) decyl ether (trade name; Fine Surf D-1307, HLB: 13.2, manufactured by Aoki Oil & Fat Co., Ltd.)
Polyoxyalkylene alkyl ether (C): polyoxyethylene (average number of moles added: 8.5) isodecyl ether (trade name; Fine Surf D-85, HLB 14.0, manufactured by Aoki Oil & Fat Co., Ltd.)
Polyoxyalkylene alkyl ether (D): polyoxyethylene (average number of moles added: 5) hexyl ether (trade name; Emulan HE50, manufactured by BASF)
Solvent diethylene glycol monobutyl ether (trade name; butyl diglycol, manufactured by Nippon Emulsifier Co., Ltd.)
Glycerin: Concentrated glycerin S (trade name, manufactured by Shin Nippon Rika Co., Ltd.)
Sorbitol: Sorbitol SP (trade name, manufactured by Food Science Co., Ltd.)
Reducing component other than oxalic acid Malic acid: DL-malic acid (manufactured by Fuso Chemical Industry Co., Ltd.)
Glycolic acid (manufactured by DuPont)
Preservative: Phenoxyethanol (manufactured by Sanyo Chemical Industries)
Hard water resistant component: sulfamic acid (manufactured by Fuso Chemical Industry Co., Ltd.)
pH adjuster: Diethanolamine (manufactured by Shell Chemicals Japan)
Viscosity modifier: xanthan gum (trade name; Kelzan ASXT, manufactured by Sansho Co., Ltd.)
Antifoaming agent: Silicone emulsion (trade name: DK Q1-1247, manufactured by Toray Dow Corning Co., Ltd.)
Fragrance: d-Limonene (manufactured by Nippon Terpene Chemical Co., Ltd.)

  The acidic reducing composition and acidic reducing detergent composition of the present invention are excellent in low-temperature stability, have high rust removal properties, and are suitably used for vehicles such as railway vehicles using stainless steel, aluminum or the like as an exterior material. can do.

Claims (9)

  An acidic reducing composition containing oxalic acid and polyvinyl alcohol.   The acidic reducing composition according to claim 1, wherein oxalic acid is 0.01 to 15 wt% and polyvinyl alcohol is 0.01 to 15 wt% in the acidic reducing composition.   The acidic reducing composition according to claim 1 or 2, wherein the ratio of oxalic acid to polyvinyl alcohol is in the range of 0.001 to 5 parts by weight with respect to 1 part by weight of oxalic acid.   The acidic reducible cleaning composition in which the acidic reducible composition in any one of Claims 1-3 contains surfactant.   The acidic reducing detergent composition according to claim 4 for removing rust from a stainless steel exterior material or an aluminum exterior material.   The acidic reducing detergent composition according to claim 4 for removing rust on an outer plate of a vehicle.   Furthermore, it contains a hard water resistant component, a chelating agent, a pH adjuster, a fragrance, a deodorant, a disinfectant, an antiseptic, a viscosity adjuster, a solvent, a builder, an antifoaming agent, or an antioxidant. The acidic reducible cleaning composition in any one of -6.   A method for increasing the solubility of oxalic acid in water, characterized by causing polyvinyl alcohol to coexist with oxalic acid.   The method of Claim 8 that the usage-amount of polyvinyl alcohol is the range of 0.001-5 weight part with respect to 1 weight part of oxalic acid.