JP2002138300A - Deterging method of blood-stained cloth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deterging method exhibiting excellent deterging effects on a fiber product having a blood stain adhered thereto. SOLUTION: A blood-stained cloth is subjected to a preliminary washing with an alkaline detergent (A) containing a water-soluble chelating agent more than a theoretical value, having a pH of at least 10 and an effective oxygen concentration of at most 30 ppm and being not higher than 45 deg.C and subsequently to normal washing with an alkaline detergent (B) containing a bleaching agent and having a pH of at least 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood-stained cloth to which special blood stains different from ordinary laundry clothes, such as sheets, wrappers, and white coats used in hotels and hospitals, such as clothing and textiles And a method for cleaning.

[0002]

2. Description of the Related Art Blood stains adhered to clothing and textiles are very difficult to remove, so they are usually preliminarily washed with water first.
Thereafter, as the main cleaning, cleaning is performed at a high temperature of 60 to 80 ° C. using a detergent, an alkali agent, and a bleaching agent in combination. At that time, in order to save labor and improve efficiency, a continuous washing machine, which is a unique washing machine in the industry, is used, and a part of the wastewater from the bleaching, softening, or sizing treatment processes is used. Is recycled to the washing tank and reused. However, the removal of dirt alone is insufficient, and re-cleaning is often performed.

[0003] Soil remaining without being removed by the main washing and re-washing often becomes more difficult to remove by passing through a drying and finishing step, and a cleaning agent or a cleaning method capable of removing blood stains well. Research has been done.

For example, Japanese Patent Application Laid-Open No. 63-190075 proposes a method of pre-cleaning a blood-contaminated cloth with an alkaline solution containing a water-soluble polymer, followed by main cleaning with a cleaning solution containing a bleaching agent. However, the cleaning effect is not yet satisfactory.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for treating a blood-contaminated cloth with water and an amount required to capture all the hardness components in the water, the amount being greater than the theoretical value (hereinafter referred to as "the amount greater than the theoretical value"). Water-soluble chelating agent), and preliminarily washed with an alkaline washing solution (A) having a pH of 10 or more and an effective oxygen concentration of 30 ppm or less at a temperature of 45 ° C. or less, and then containing a bleach containing a pH of 10 or more. The present invention relates to a method for cleaning a blood-contaminated cloth to be main-cleaned with an alkaline cleaning liquid (B). Cleaning solution (A),
The pH of (B) is preferably the pH at the temperature during washing.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have found that the above-described two-stage cleaning method is effective for completely cleaning sheets and the like to which blood stains have adhered.

That is, the method for cleaning a blood-contaminated cloth of the present invention comprises:
In the first step, the object to be washed is firstly treated with a water-soluble chelating agent in an amount not less than the theoretical value at a pH of 10 or more and an effective oxygen concentration of 3 or more.
Preliminary washing with an alkaline cleaning solution of 0 ppm or less and a temperature of 45 ° C. or less (hereinafter referred to as “cleaning solution (A)”) to substantially remove dirt, and then, as a second step, an alkaline cleaning solution containing a bleaching agent having a pH of 10 or more [hereinafter, a cleaning solution (B) )), And the cleaning method is characterized in that red or reddish brown stains derived from blood can be almost completely removed, and a clean fiber product can be obtained.

In the present invention, the first step (preliminary cleaning)
At pH above the theoretical value containing a water-soluble chelating agent
Preliminary cleaning is performed with a cleaning liquid (A) having a concentration of 10 or more, an effective oxygen concentration of 30 ppm or less, and a temperature of 45 ° C. or less. Unless such preliminary cleaning with the cleaning liquid (A) is performed, blood stains cannot be sufficiently removed. In the present invention, stains cannot be completely removed only by the first stage, but the stains of blood can be removed by performing the main washing step of washing with a washing solution (B) containing a bleaching agent having a pH of 10 or more as a second stage. Dirt can be almost completely removed.

The water-soluble chelating agents used in the washing liquid (A) include ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, triethylenetetraminehexaacetic acid, phosphonic acid, tripolyphosphoric acid, ethylene glycol bis (2-aminoethyl ether) tetraacetic acid, citric acid, maleic acid, polyacrylic acid, isoamylene-maleic acid copolymer, acrylic acid-maleic acid copolymer, acrylic acid-methacrylic acid copolymer, gluconic acid, hydroxy One or more selected from benzyliminodiacetic acid, iminodiacetic acid and salts thereof are preferred. Among them, one or more selected from ethylenediaminetetraacetic acid, tripolyphosphoric acid and salts thereof are preferable. The water-soluble chelating agent is used in an amount greater than or equal to the theoretical value for capturing all the hardness components in the cleaning liquid (A), but is preferably 1 to the theoretical value.
~ 3 times. The washing liquid (B) can also contain the above-mentioned water-soluble chelating agent, but in such a case, it is preferable that the washing liquid (B) is contained in an amount of a theoretical value or more. Under these conditions, the cleaning solution (A)
Preferably contains 0.001 to 0.5% by weight of a water-soluble chelating agent.

[0010] The hardness components in water are calcium and magnesium, and the amount of all the hardness components is expressed by the concentration of a calcium compound in a unit amount of water in terms of German hardness, American hardness and the like. The German hardness is expressed in terms of CaO converted from all hardness components in mg / 100 ml of water (unit: ° D).
H), American hardness represents the amount obtained by converting the total hardness ingredients CaCO ₃ in mg / L (unit: ppm) are those. Both have American hardness (ppm) = German hardness (° D
H) × 17.85.

On the other hand, the chelating agent can determine the amount of CaCO ₃ trapped per unit weight of the compound by an electric conductivity titration method or the like, so that the hardness of water and the amount of CaCO ₃ trapped by the chelating agent can be determined. The theoretical value of the amount of chelating agent needed to capture all the hardness components in the water of interest can be calculated. For example, sodium tripolyphosphate has a CaCO ₃ trapping amount of 460 mg / g, and thus has a hardness of 6 ° DH (total hardness component concentration is 10% as CaCO _3).
When 7.1 mg / L of water is used, in order to capture all the hardness components, 0.233 g (10
7.1 / 460). This amount is the theoretical value. The washing liquid (A) is obtained by adding to a water a water-soluble chelating agent in an amount equal to or more than the theoretical value of an amount necessary to capture all the hardness components in the water.

Further, the cleaning solution (A) contains an alkali agent to adjust the pH to 10 or more. As the alkaline agent, 1
No. 2 sodium silicate, No. 3 sodium silicate, sodium carbonate, sodium hydroxide, potassium hydroxide, sodium sesquicarbonate, sodium borate, sodium orthosilicate, sodium metasilicate and the like. These alkaline agents can be used in any concentration as long as the pH of the cleaning solution (A) is not less than 10 at a temperature of 45 ° C. or lower. A range of １1% by weight is suitable.

[0013] If active oxygen is present in the cleaning solution (A), blood dirt becomes difficult to be cleaned by oxidation. Therefore, the effective oxygen concentration of the cleaning liquid (A) is 20 ppm or less,
10 ppm is preferred. The available oxygen concentration is adjusted by adding enzymes such as sodium thiosulfate, hydrosulfite (sodium dithionite), sodium sulfite, sodium bisulfite, thiourea dioxide, Rongalite (sodium sulfoxylate), catalase, etc. it can. Alternatively, it can be adjusted by minimizing the amount of recycled water containing available oxygen and using a large amount of new water. The effective oxygen concentration is determined according to JIS K 3362.
It was measured according to 7.9.

The washing liquid (A) is preferably at most 40 ° C., more preferably at 15 to 35 ° C., particularly preferably at 20 to 30 ° C.
Used at a temperature of ° C. The cleaning time of the pre-cleaning is 5
~ 15 minutes is preferred.

The main washing in the second stage is carried out at pH 1 containing a bleaching agent.
It can be carried out in the same manner as in a conventional method using zero or more washing liquids (B). The cleaning liquid (B) also contains an alkaline agent as shown in the cleaning liquid (A) in order to make the pH 10 or more. The bleaching agent used for the cleaning liquid (B) includes hydrogen peroxide,
Perborates such as sodium perborate, percarbonates such as sodium percarbonate, sodium sulfate / salt / H ₂ O ₂ adduct, urea / H ₂ O ₂ /
Gypsum adducts, inorganic peroxides such as potassium monopersulfate, organic peroxides such as dodecane diperacid (DPDA), monoperphthalic acid (commercially available as magnesium monoperphthalate hexahydrate); And chlorine bleach such as hypochlorite and chlorinated isocyanuric acid. Among them, one or more selected from hydrogen peroxide, percarbonate (particularly sodium percarbonate) and perborate (particularly sodium perborate) are preferable.

The concentration of the bleaching agent in the washing solution (B) is 0.001 to 0.5% by weight, preferably 0.005 to 0.1% by weight as effective oxygen in the case of an oxygen-based bleaching agent, and a chlorine-based bleaching agent. In this case, the effective chlorine is 0.001 to 0.1% by weight, preferably 0.005 to 0.05% by weight.

The washing liquid (B) may contain a surfactant, a builder or a detergent containing these. As the surfactant, the surfactant is preferably at least one selected from a nonionic surfactant, a cationic surfactant, an amphoteric surfactant and an anionic surfactant.

Examples of the nonionic surfactant include sorbitan fatty acid ester, polyoxyalkylene sorbitan fatty acid ester, polyoxyalkylene fatty acid ester, glycerin fatty acid ester, polyoxyalkylene glycerin fatty acid ester, polyglycerin fatty acid ester,
Polyoxyalkylene polyglycerin fatty acid ester,
Sucrose fatty acid ester, resin acid ester, polyoxyalkylene resin acid ester, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl phenyl ether, alkyl (poly) glycoside, polyoxyalkylene alkyl (poly) glycoside, and the like. Preferably, a nonionic surfactant containing an ether group and a nonionic surfactant containing an ester group that do not contain a nitrogen atom are used.

Examples of the anionic surfactant include carboxylic acid-based, sulfonic acid-based, sulfate-based and phosphate-based surfactants, and carboxylic acid-based and phosphate-based surfactants are preferred. Examples of the carboxylic acid surfactant include fatty acids having 6 to 30 carbon atoms or salts thereof, polyvalent carboxylate, polyoxyalkylene alkyl ether carboxylate, polyoxyalkylene alkyl amide ether carboxylate, rosinate, Dimer acid salt, polymer acid salt, tall oil fatty acid salt and the like can be mentioned.
Examples of the sulfonic acid surfactant include alkyl benzene sulfonate, alkyl sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate, diphenyl ether sulfonate, condensate of alkyl naphthalene sulfonic acid, and condensation of naphthalene sulfonic acid. Salt and the like. Examples of the sulfate-based surfactant include alkyl sulfates, polyoxyalkylene alkyl sulfates, polyoxyalkylene alkyl phenyl ether sulfates, tristyrenated phenol sulfates, and polyoxyalkylene distyrenated phenol sulfates. And alkyl polyglycoside sulfates. As phosphate ester surfactants,
For example, an alkyl phosphate ester salt, an alkylphenyl phosphate ester salt, a polyoxyalkylene alkyl phosphate ester salt, a polyoxyalkylene alkylphenyl phosphate ester salt and the like can be mentioned. Examples of the salt include metal salts (Na, K, Ca, Mg, Zn, etc.), ammonium salts, alkanolamine salts, and aliphatic amine salts.

Examples of the amphoteric surfactant include amino acids, betaines, imidazolines, and amine oxides. Examples of the amino acid system include acyl amino acid salts, acyl sarcosine salts, acyloylmethylaminopropionates, alkylaminopropionates, and acylamidoethylhydroxyethylmethylcarboxylates. Examples of the betaine include alkyl dimethyl betaine, alkyl hydroxyethyl betaine, acylamidopropylhydroxypropyl ammonia sulfobetaine, acylamidopropylhydroxypropyl ammonia sulfobetaine, ricinoleic acid amidopropyldimethylcarboxymethyl ammonia betaine, and the like. Examples of the imidazoline-based compounds include alkylcarboxymethylhydroxyethyl imidazolinium betaine and alkylethoxycarboxymethylimidazolium betaine. Examples of the amine oxides include alkyldimethylamine oxide, alkyldiethanolamine oxide, and alkylamidopropylamine oxide. The concentration of the surfactant in the cleaning solution (B) is preferably 0.0001 to 0.5% by weight, more preferably 0.001 to 0.05% by weight. In addition,
The washing liquid (A) can also contain the surfactant in the same range as described above.

As the surfactant, a nonionic surfactant represented by the following general formula (I) is preferable. When this surfactant is used, it may be added to any of the cleaning liquids (A) and (B), but it is preferable that both contain the surfactant. R ¹ -O- (EO) _o- (PO) _p- (EO) _q -H (I) wherein R ¹ represents an alkyl group or an alkenyl group having an average carbon number of 8 to 18, and EO represents oxyethylene The group, PO, represents an oxypropylene group. o, p and q each represent an average number of moles, and o> 0, preferably o = 2 to 10, q
> 0, preferably q = 2-10, p = 1-6, preferably p = 1-5, and o + p + q = 4-20, preferably 6-14. ].

The nonionic surfactant represented by the general formula (I) is used in the cleaning solution (A) in an amount of 0.0001 to 0.1.
It is preferably used at a concentration of 5% by weight, more preferably 0.001 to 0.05% by weight, and in the cleaning liquid (B), 0.0001 to 0.5% by weight, and more preferably 0.001 to 0.05% by weight.

The washing liquid (B) may contain, as an optional component, a component which is conventionally known to be added to a detergent. As such optional components, (1)
Alcohols such as ethanol, ethylene glycol, glycols such as low molecular weight polyethylene glycol and propylene glycol having a molecular weight of 200 to thousands or more,
(2) para-toluenesulfonic acid, benzoate (which also has an effect as a preservative), and a thickener or solubilizer such as urea;
(3) phase adjuster and polyoxyalkylene benzyl ether and polyoxyalkylene phenyl ether for improving detergency, (4) chelating agent as shown in washing liquid (A), (5) color transfer of polyvinylpyrrolidone, etc. Inhibitors, (6) enzymes such as amylase, protease, lipase, and cellulase; (7) enzyme stabilizers such as calcium chloride, calcium sulfate, formic acid, and boric acid (boron compound);
(8) a fluorescent dye, (9) silicone for imparting flexibility, (10) silica or silicone as an antifoaming agent,
(11) Antioxidants such as butylhydroxytoluene, distyrenated cresol, sodium sulfite, and sodium hydrogen sulfite; and (12) besides, bluing agents, flavors, antibacterial preservatives and the like. In addition, the cleaning liquid (A) can also contain the above components.

The washing liquid (B) is at 40 to 80 ° C.,
It is preferably used at a temperature of 80C, especially 60-80C. Further, the washing time of the main washing is preferably 10 to 30 minutes.

In the present invention, a water having a hardness of 2 to 14 ° DH, particularly 4 to 10 ° DH is used for the cleaning solution (A) and the water for preparing the cleaning solution. And / or can be effectively used for the preparation of (B). This is particularly effective when the hardness of water such as well water is high.

In the present invention, after the first stage cleaning with the cleaning liquid (A), the second stage main cleaning may be performed by draining the water, or after the first stage cleaning with the cleaning liquid (A), The second-stage main cleaning may be performed without performing drainage. The cleaning method of the present invention is suitable for a cleaning system in which steps such as preliminary cleaning, main cleaning, and rinsing are automated and continuously performed.

[0027]

According to the cleaning method of the present invention, it is possible to completely remove blood stains on blood-contaminated cloth used in hotel linens, hospital linens and the like.

[0028]

Examples 1 to 6 and Comparative Examples 1 to 7 Using blood-contaminated cloth (No. 111 cotton manufactured by Swiss EMPA), pre-cleaning was performed using the cleaning solution (A) shown in Table 1 under the conditions shown in Table 1. Then, after drainage and dehydration, main cleaning was performed using the cleaning liquid (B) shown in Table 1 under the conditions shown in Table 1, and the cleaning rate was evaluated. Table 1 shows the evaluation results. The cleaning rate of the blood-contaminated cloth was determined by measuring the reflectance of the cloth before and after cleaning (measurement wavelength 5
20 nm) and was calculated by the following equation. In the cleaning liquid (A), the effective oxygen concentration was adjusted to 10 ppm for Example 5 and Comparative Example 1, and to 40 ppm for Comparative Examples 2 and 6, using hydrogen peroxide, respectively.

[0029]

(Equation 1)

[0030]

[Table 1]

(Note) * Sodium polyacrylate: Weight average molecular weight 5000 * Nonionic surfactant (1): Ethylene oxide average 8 mol adduct of alcohol having a linear primary mixed alkyl group having 12 to 14 carbon atoms * non-ionic surface active agent (2): primary mixed alkyl group of R ¹ in the general formula (I) is an average of 12 carbon atoms, o = 5, p =
2, q = 5 * Commercial detergent: for bioharvest linen (Kao Corporation)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C11D 3/20 C11D 3/20 3/26 3/26 3/37 3/37 3/395 3/395 7/16 7 / 16 7/22 7/22 7/26 7/26 7/32 7/32 17/08 17/08 D06L 1/16 D06L 1/16 (72) Inventor Shinya Saito 1334 Minato 1334 Minato, Wakayama-shi, Wakayama Kao Corporation Within the laboratory (72) Inventor Shigeru Tamura 1334, Minato, Wakayama, Wakayama Pref. EB08 EB12 EB13 EB15 EB16 EB30 EB32 ED02 EE04 EE05 FA28 FA42

Claims (5)

[Claims] 1. A blood-contaminated cloth containing water and a water-soluble chelating agent in an amount not less than the theoretical value required to capture all the hardness components in the water, has a pH of 10 or more, and has an effective oxygen concentration of 30 or more.
After preliminarily cleaning using an alkaline cleaning solution (A) of 45 ppm or less at a temperature of 45 ° C. or less, a pH 10 containing a bleaching agent is used.
A method for cleaning a blood-contaminated cloth, which is main-cleaned with the above alkaline cleaning liquid (B). 2. The cleaning method according to claim 1, wherein the cleaning liquid (A) and / or (B) contains a nonionic surfactant represented by the following general formula (I). R ¹ -O- (EO) _o- (PO) _p- (EO) _q -H (I) wherein R ¹ represents an alkyl group or an alkenyl group having an average carbon number of 8 to 18, and EO represents oxyethylene The group, PO, represents an oxypropylene group. o, p, and q each represent an average number of moles, and o> 0, q> 0, and p = 1 to 6,
And o + p + q = 4-20. ] 3. The water-soluble chelating agent is ethylenediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, triethylenetetraminehexaacetic acid, phosphonic acid,
Tripolyphosphoric acid, ethylene glycol bis (2-aminoethyl ether) tetraacetic acid, citric acid, maleic acid,
Polyacrylic acid, isoamylene-maleic acid copolymer,
3. The cleaning method according to claim 1, wherein the cleaning method is at least one selected from an acrylic acid-maleic acid copolymer, an acrylic acid-methacrylic acid copolymer, gluconic acid, hydroxybenzyliminodiacetic acid, iminodiacetic acid, and salts thereof. 4. The cleaning method according to claim 1, wherein the bleaching agent is at least one selected from hydrogen peroxide, percarbonate and perborate. 5. The cleaning method according to claim 1, wherein the cleaning liquid (A) contains 0.001 to 0.5% by weight of a water-soluble chelating agent.