Sheet type bleach

Abstract

The present disclosure relates to sheet-type bleach. The sheet-type bleach of the present disclosure comprises an organic acid and an organic acid salt together with a water-soluble polymer, and thus not only has excellent bleaching power, but also has excellent formulation stability and excellent drying efficiency because the tensile strength of the sheet is appropriately formed.

Description

Sheet-type bleach

[0001] This application claims priority to Republic of Korea Application No. 10-2023-0075835, filed June 13, 2023, and Republic of Korea Application No. 10-2023-0135383, filed October 11, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a sheet-type bleaching agent.

[0003] Conventional fabric detergents are primarily sold in two forms: powder and liquid. For liquid detergents, consumers measure the appropriate amount from the container according to the intended use. However, this can lead to spills and contamination of the surrounding area. Powder detergents, on the other hand, can cause inconveniences such as dusting.

[0004] To address these shortcomings, sheet-type detergent formulations are being developed, featuring single-packaged detergents. These sheet-type detergents are not only easy to store and convenient to use, but their large surface area also allows for excellent water solubility and water dispersibility of active ingredients during the washing process.

[0005] Fabric detergents can be divided into laundry detergents and bleaches. Laundry detergents target general stains, such as particulate matter, oily matter, or human-derived stains, while bleaches target pigments that are difficult to remove with laundry detergents.

[0006] Typically, common bleaching ingredients such as hydrogen peroxide, sodium percarbonate, or chlorine bleach can be used as the active ingredient of bleaching agents. However, sheet-type detergents are generally subjected to high temperatures of 100 to 150°C during the drying stage of the slurry during the manufacturing process. When manufacturing sheet-type detergents, the common bleaching ingredients mentioned above are likely to be hydrolyzed when included in water, and hydrolysis is particularly accelerated when high temperatures are applied. Accordingly, bleaching ingredients that have gone through the drying process lose their function, making it difficult to include bleaching ingredients in existing sheet formulations. In addition, although inorganic compounds such as talc are sometimes used in excess as fillers in sheet-type detergents, there is a problem that the talc remains when dissolved in water, contaminating the laundry.

[0007] The problem that the present disclosure seeks to solve is to provide a sheet-type bleaching agent that stably includes a heat-stable bleaching ingredient in the formulation in order to solve the problems of the existing sheet-type bleaching agent as described above.

[0008] In addition, the problem to be solved by the present disclosure is to provide a sheet-type bleaching agent that not only has excellent bleaching power, but also forms a tensile strength suitable for production, so that it can be formulated, and also has excellent drying efficiency.

[0009] In addition, the problem to be solved by the present disclosure is to provide a sheet-type bleaching agent having excellent formulation stability by forming an appropriate tensile strength while not containing talc and thus not leaving talc in laundry.

[0010] In addition, the problem to be solved by the present disclosure is to provide a bleaching use of a sheet-type bleaching agent having excellent bleaching power and formulation stability, and a method for producing such a sheet-type bleaching agent.

[0011] The inventors of the present invention have diligently researched and worked to solve the above problems, and as a result, have discovered that when an organic acid is used as a bleaching ingredient in a sheet-type bleach, it is heat-stable and has excellent bleaching power. However, when an organic acid is included in excess during the manufacture of a sheet-type bleach, problems may arise in that the formulation and drying efficiency of the sheet are reduced. Therefore, the inventors of the present invention have discovered that when an organic acid and an organic acid salt are included together when formulating a sheet-type bleach using a water-soluble polymer, not only is the bleaching power excellent, but the tensile strength for formulation is appropriately formed and the drying efficiency is also excellent, thereby completing the present invention.

[0012] The present disclosure provides a sheet-shaped bleaching agent comprising an organic acid, an organic acid salt, and a water-soluble polymer.

[0013] In one aspect of the present disclosure, the "sheet" may refer to a formulation in which a water-soluble polymer is solidified into a flat sheet shape, such as, but not limited to, a film-like formulation. The sheet may, for example, be in a flat rectangular shape, but is not limited thereto.

[0014] In one aspect of the present disclosure, the term "bleach" may refer to a product used in everyday life to remove stains from clothing and the like, whiten discolored items, or brighten primary colors. The bleach may be used to remove stains that are difficult to remove with standard detergents.

[0015] In one aspect of the present disclosure, the organic acid may be at least one selected from the group consisting of citric acid, lactic acid, acetic acid, formic acid, and oxalic acid, but is not limited thereto. Preferably, the organic acid may be citric acid, which is heat stable and has excellent bleaching power when producing a sheet-type bleach.

[0016] In one aspect of the present disclosure, the organic acid salt may be a conventional salt of the corresponding organic acid, for example, the organic acid salt includes at least one of an inorganic salt and an organic salt of the organic acid, the inorganic salt includes at least one selected from the group consisting of a sodium salt, a potassium salt, a calcium salt, a magnesium salt, an aluminum salt, a zinc salt, and the like, the organic salt includes at least one selected from the group consisting of an organic amine salt and a basic amino acid salt, and the organic amine salt includes at least one selected from the group consisting of an ammonium salt, a monoethanolamine salt, a diethanolamine salt, a triethanolamine salt, and the like, and the basic amino acid salt includes at least one selected from the group consisting of an arginine salt and a lysine salt, but is not limited thereto.

[0017] In one aspect of the present disclosure, the weight ratio of the organic acid and the organic acid salt may be 10:1 to 1:1, preferably 7:1 to 1:1, and more preferably 5:1 to 1:1 (organic acid:organic acid salt). When the organic acid and the organic acid salt are included in the sheet-shaped bleach of the present disclosure in the weight ratio as described above, not only is the bleaching power excellent, but the tensile strength for formulation and the drying efficiency are also significantly improved.

[0018] In one aspect of the present disclosure, the organic acid and organic acid salt may be included in an amount of 3 to 40 wt%, preferably 7 to 35 wt%, and more preferably 10 to 30 wt%, relative to the total weight of the sheet-type bleaching agent. When the content of the organic acid and organic acid salt is within the above range, not only is the bleaching power excellent, but the tensile strength for formulation and drying efficiency are also significantly improved.

[0019] In one aspect of the present disclosure, the "total weight of the sheet-type bleach" is substantially equal to the "dry weight of the sheet-type bleach." Since the sheet-type bleach can be manufactured by thinly applying a compounding solution and then drying it, the total weight of the finished sheet-type bleach is substantially equal to the dry weight.

[0020] In one aspect of the present disclosure, the water-soluble polymer may be at least one selected from the group consisting of polyvinyl alcohol (PVA), a polyvinyl alcohol copolymer, gelatin, pectin, dextran, hyaluronic acid, collagen, agar, gum arabic, gum acacia, alginic acid, sodium alginate, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, starch, dextrin, carboxymethyl starch, polyvinylpyrrolidone, polyvinyl methacrylate, polyacrylic acid, and polyethylene oxide, but is not limited thereto.

[0021] Preferably, the water-soluble polymer may include polyvinyl alcohol (PVA). When polyvinyl alcohol is used together with the organic acid and organic acid salt to solidify the sheet-shaped bleach of the present disclosure, the tensile strength of the sheet is appropriately formed, facilitating formulation and improving drying efficiency.

[0022] In one aspect of the present disclosure, the polyvinyl alcohol may be a polyvinyl alcohol having a degree of saponification of 75 mol% or more, preferably 77 mol% or more, and more preferably 80 mol% or more. The upper limit of the degree of saponification of the polyvinyl alcohol may be 100 mol% or less, preferably 99 mol% or less. The sheet-shaped bleach of the present disclosure includes polyvinyl alcohol having the specific degree of saponification together with an organic acid and an organic acid salt, thereby forming the tensile strength of the sheet appropriately, enabling formulation, and significantly improving drying efficiency.

[0023] In one aspect of the present disclosure, the water-soluble polymer may be present in an amount of 15 to 60 wt%, preferably 20 to 50 wt%, and more preferably 25 to 45 wt%, relative to the total weight of the sheet-shaped bleach. When the water-soluble polymer, preferably polyvinyl alcohol, is included within the weight range described above, the formulation stability and drying efficiency of the sheet-shaped bleach are excellent.

[0024] In one aspect of the present disclosure, the molecular weight of the water-soluble polymer may be 10,000 to 50,000 MW, preferably 20,000 to 30,000 MW. When the molecular weight of the water-soluble polymer, preferably polyvinyl alcohol, is within the above range, the formulation stability and drying efficiency of the sheet-type bleaching agent are excellent.

[0025] In one aspect of the present disclosure, the weight ratio of the organic acid and organic acid salt:water-soluble polymer included in the sheet-shaped bleaching agent may be 1:1 to 1:10, preferably 1:1 to 1:5 (organic acid and organic acid salt:water-soluble polymer). Preferably, the water-soluble polymer in the weight ratio may be polyvinyl alcohol. When the components are included within the weight ratio range, not only is the bleaching power excellent, but also an appropriate tensile strength is formed, resulting in excellent formulation stability and increased drying efficiency.

[0026] In one aspect of the present disclosure, the sheet-type bleach may be substantially free of inorganic compounds. The inorganic compounds may be, but are not limited to, talc, zeolite, silicon dioxide, or colloidal silica. The inorganic compounds may be substantially free of the sheet-type bleach, may be contained in an amount of less than 1 wt%, preferably less than 0.5 wt%, or may not be contained at all, relative to the total weight of the sheet-type bleach. The sheet-type bleach of the present disclosure can prevent contamination of laundry by inorganic compounds, and even if it does not substantially contain inorganic compounds, it has excellent formulation stability by forming an appropriate tensile strength.

[0027] In one aspect of the present disclosure, the sheet-type bleach can further comprise a plasticizer to form an appropriate tensile strength, thereby improving formulation stability and drying efficiency. The plasticizer can prevent clumping during the preparation of the formulation of the sheet-type bleach, and since the inclusion of the plasticizer eliminates the need for additional water addition, drying efficiency can be improved. The plasticizer may be at least one selected from the group consisting of sorbitol, mannitol, glycerin, glycol, pentaerythritol, and polyol, but is not limited thereto. The plasticizer may be comprised in an amount of 3 to 8 wt%, preferably 3 to 6 wt%, relative to the total weight of the sheet-type bleach.

[0028] In one aspect of the present disclosure, the pH of the sheet-shaped bleach may be 6 or less, preferably 5.9 or less, or the pH may be 4 to 6. As such, the sheet-shaped bleach of the present disclosure has remarkably excellent bleaching power as it has a pH in the above range.

[0029] In addition, in one aspect of the present disclosure, the thickness of the sheet of the sheet-type bleaching agent may be 0.05 to 0.5 cm, preferably 0.1 to 0.3 cm. When the thickness of the sheet is within the above range, the active ingredient can be sufficiently contained, the strength of the sheet is increased, and the dissolution rate is appropriate, thereby improving the bleaching performance.

[0030] In one aspect of the present disclosure, the sheet-type bleaching agent may optionally include, but is not limited to, a stabilizer, silicone oil, a radical scavenger, a chelating agent, a pH adjusting agent, a nonionic surfactant, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a fragrance, a preservative, or a colorant.

[0031] Additionally, the present disclosure provides a bleaching application of a sheet-type bleaching agent comprising an organic acid, an organic acid salt, and a water-soluble polymer. The bleaching application not only exhibits excellent formulation stability and drying efficiency, but also exhibits remarkably excellent bleaching power by using the sheet-type bleaching agent.

[0032] In addition, the present disclosure provides a method for producing a sheet-shaped bleach, comprising the steps of (s1) dissolving an organic acid, an organic acid salt, and a water-soluble polymer in water; and (s2) forming the dissolved mixture into a sheet having a predetermined thickness and then drying it. In one aspect of the present disclosure, step (s1) of the production method may additionally dissolve a plasticizer in water. Preferably, step (s1) may dissolve the water-soluble polymer in water, then dissolve the plasticizer, and then dissolve the organic acid and the organic acid salt. The overall content regarding the sheet-shaped bleach may be equally applied to the production method.

[0033] The sheet-type bleaching agent of the present disclosure not only has excellent bleaching power by including a water-soluble polymer together with an organic acid and an organic acid salt, but also has excellent formulation stability and excellent drying efficiency by forming the tensile strength of the sheet appropriately.

[0034] Figure 1 is a photograph of the dried sheet shape of the sheet-shaped bleaching agent of Comparative Examples 2-1 to 2-5 and Examples 2-1 to 2-2 manufactured in Experimental Example 2.

[0035] Figure 2 is a photograph taken with an optical microscope of the sheet-shaped bleaching agents of Comparative Examples 2-1 and 2-5 and Examples 2-1 and 2-2, and shows the results of observing the bubbles formed therein.

[0036] Figure 3 is a photograph of the dried sheet shape of the sheet-shaped bleach of Comparative Example 4-1 manufactured in Experimental Example 5.

[0037] Figure 4 shows the results of evaluating the solubility of the sheet of Comparative Example 4-1 by dissolving it in water in Experimental Example 5.

[0038] Hereinafter, the present invention will be described in detail, using examples and the like, to aid understanding. However, the examples according to the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited to the following examples. The examples of the present invention are provided to more fully explain the present invention to those of average skill in the art.

[0039]

[0040] Experimental Example 1: Formulation of sheet-type bleaching agent and evaluation of bleaching power

[0041] Sheet-type bleaching agents of examples and comparative examples were prepared according to the compositions described in Table 1 below. In Table 1 below, the content of each component is expressed as a weight % based on the dry weight of the sheet. Each sheet-type bleaching agent was prepared using the following manufacturing method.

[0042] Manufacturing method:

[0043] (1) Each component was dissolved in water at 60°C according to the weight ratio shown in Table 1 below, and a final mixture solution having a water content of 48 wt% was prepared.

[0044] (2) The mixture was applied to the release paper at a thickness of 1.5 mm using a comma cutter.

[0045] (3) After drying in a 125℃ oven for 10.5 minutes, the sheet manufacturing was completed.

[0046] Comparative Example 1-1 Comparative Example 1-2 Comparative Example 1-3 Comparative Example 1-4 Comparative Example 1-5 Example 1-1 Example 1-2 Example 1-3 Example 1-4 Example 1-5 Example 1-6 PVA (MW 22,000, saponification degree 88 mol%) 38.8 144.39 44.39 44.39 31.89 43.39 39 39 39 41.89 39 39 39 34.39 32.39 SLS 5 2.0 8 5 3.6 15 0.0 6 45.6 145.6 145.6 145.6 145.6 145.6 145.6 145.6 145.6 145.6 145.6 1 sodium carbonate 9.1 100000000000 citric acid025.510105.57.510101015sodium citrate000012.55.57.52.55107.5total100100100100100100100100100100100100citric acid: sodium citrate ratio----1:1.251:11:14:12:11:12:1pH6.866.915.605.025.405.825.425.185.225.264.95sheet formulation43221443444bleaching power - 1 (C-BC_02)0.420.50.610.750.750.630.680.730.780.770.84 Bleaching power - 2 (C-BC-03)0.280.360.822.212.220.801.292.262.242.182.59

[0047] In addition, the pH of the above examples and comparative examples was measured, and the sheet formulation and bleaching power were evaluated, which are shown in the lower part of Table 1. Comparative Example 1-1 is a general sheet-type laundry detergent containing sodium carbonate. It was confirmed that although basic laundry detergents can be formulated, they have poor bleaching power and are not suitable for use as bleaching agents. It was confirmed that the bleaching power increased when citric acid was included (Comparative Examples 1-2 to 1-4), but sheet formulation was not possible. Looking at the experimental results, it was confirmed that the sheet-type bleaching agents of Examples 1-1 to 1-6 had excellent bleaching power and that the sheet formulation was also stable.

[0048]

[0049] <pH 측정 방법>

[0050] The pH was measured at room temperature using a standard usage concentration of 0.089 g / L.

[0051]

[0052] <Formulation Evaluation Method>

[0053] The formulation evaluation was based on the direction of force applied when separating the sheet from the release paper after sheet manufacturing. The evaluation score was rated from 1 to 4 points based on the criteria below.

[0054] 1 point: Sheet is torn

[0055] 2 points: Deformation of the sheet length exceeding 30%

[0056] 3 points: Deformation of the sheet length by more than 10% but less than 30%

[0057] 4 points: Deformation of the sheet length by less than 10%

[0058]

[0059] <Bleaching power evaluation method>

[0060] The bleaching power evaluation was performed as follows.

[0061] 1. Color difference measurement (L*, a*, b*) of standard contaminated cloth (C-BC-02, C-BC-03, manufacturer: center for test materials) before washing

[0062] 2. Bleaching in Terg-O-Tometer with a standard usage of 0.09g / L of sheet-type bleach (10 minutes, 20℃, hardness 50ppm, speed 100rpm)

[0063] 3. Rinse twice and dry for more than 12 hours.

[0064] 4. Color difference measurement after washing of dried standard contaminated cloth

[0065] 5. Calculating bleaching power

[0066] (For reference, the bleaching power of a general liquid detergent for C-BC_02 is 0.67, and the bleaching power of a general liquid detergent for C-BC-03 is 0.88)

[0067]

[0068] Experimental Example 2: Evaluation of the physical properties of sheet-type bleaching agent

[0069] According to the manufacturing method below, Comparative Examples 2-1 to 2-5 and Examples 2-1 to 2-2 were manufactured by varying the degree of saponification of polyvinyl alcohol as shown in Table 2 below.

[0070] Manufacturing method:

[0071] (1) Each component was dissolved in water at 60°C according to the weight ratio described in Table 2 below, and a final mixture solution having a water content of 48 wt% was prepared.

[0072] (2) The mixture was applied to the release paper at a thickness of 1.5 mm using a comma cutter.

[0073] (3) After drying in an oven at 125℃ for 8 minutes, the sheet manufacturing was completed.

[0074] Comparative Example 2-1 Comparative Example 2-2 Comparative Example 2-3 Comparative Example 2-4 Comparative Example 2-5 Example 2-1 Example 2-2 PVA (MW 22,000) Saponification (mol%) 72728288728288 Composition (wt% based on sheet dry weight) PVA 25 272727252525 SLS 46 494949484848 Laureth-78999666 Sodium carbonate 7000000 Citric acid 0000 101010 Sodium citrate 0000 777 Sorbitol (Plasticizer) 14 15 15 15 000 Glycerin (Plasticizer) 0000 444 Total 100 100 100 100 100 100 100

[0075] The physical properties of each of the above examples and comparative examples were evaluated and are shown in Table 3 below.

[0076] Experimental Results pHWidth (cm)Length (cm)Thickness (cm)Thickness Increase Rate (%)Sheet FormulationDrying EfficiencyComparative Example 2-16.862.560.183224◎Comparative Example 2-27.012.560.190294○Comparative Example 2-36.902.560.177184◎Comparative Example 2-46.962.560.143-54○Comparative Example 2-55.422.560.128-14.72△Example 2-15.372.560.146-2.74○Example 2-25.432.560.201344◎

[0077] In addition, the viscosity of the pre-drying mixture of Comparative Examples 2-1 and 2-5 and Examples 2-1 and 2-2, the weight of the sheet, the density of the sheet, and the tensile strength of the sheet were measured and shown in Table 4 below.

[0078] Experimental results Viscosity (cP) of the mixture before drying Weight (g) Density (g / cm 3 )Tensile strength (N / m) 2 ) Comparative Example 2-1-0.510.18672,131.15 Comparative Example 2-513,9970.320.16856,250.00 Exemplary Example 2-115,7970.340.15560,273.97 Exemplary Example 2-228,3940.370.12468,325.04

[0079] The above Comparative Example 2-1 is a typical sheet-type laundry detergent containing sodium carbonate. Looking at the above Comparative Example 2-5 and Examples 2-1 to 2-2, it can be seen that as the PVA saponification degree increases, the viscosity of the mixture before drying increases. It was confirmed that the higher the viscosity of the mixture, the better the bubbles within the mixture are maintained during drying, which increases the thickness and decreases the density, resulting in excellent drying efficiency and, accordingly, an increase in tensile strength. It was confirmed that the above Examples 2-1 and 2-2 have remarkably excellent drying efficiency, resulting in excellent formulation and tensile strength.

[0080] The sheet shapes of the above examples and comparative examples after drying were photographed and shown in Fig. 1. As can be seen from Fig. 1, Examples 2-1 and 2-2 show excellent formulation stability and excellent drying efficiency as there is no sheet deformation after drying.

[0081]

[0082] <Method for measuring viscosity of a mixing solution>

[0083] The ingredients in Table 2 were dissolved in water at 60°C to prepare a mixture with a total moisture content of 48%. Immediately after preparation, foam was removed from the mixture using a centrifuge. After the mixture was left indoors to cool to 25°C, the viscosity was measured using a Brookfield viscometer. Measurement conditions: 25°C, 3.0 rpm, spindle speed 64, 1 minute.

[0084]

[0085] <pH 측정 방법>

[0086] The pH was measured at room temperature using a standard usage concentration of 0.089 g / L.

[0087]

[0088] <Method of measuring tensile strength>

[0089] The bottom 1 cm of the dried sheet was removed, and a 6 cm sample was taken from the top. Three samples were prepared, each 2.5 cm in width, and the average thickness and average weight were measured. The samples were pulled at a speed of 500 mm / min using a Zwick Roell machine. The maximum force (N) at which the sample broke was measured, and the tensile strength was determined by dividing it by the area (width × height).

[0090]

[0091] <Formulation Evaluation Method>

[0092] The formulation evaluation was conducted in the same manner as in Experimental Example 1 above.

[0093]

[0094] <Drying efficiency evaluation method>

[0095] The shape of the dried sheet was confirmed with the naked eye.

[0096] X: The sheet is torn during the separation process from the release paper.

[0097] △: The sheet is separated from the release paper without tearing, but the length of the sheet is deformed during the process.

[0098] ○: The sheet is separated from the release paper without tearing, and the length of the sheet is not deformed during the process, but the drying state is different in some parts of the sheet.

[0099] ◎: The sheet is separated from the release paper without tearing, the length of the sheet is not deformed during the process, and the dryness is the same in all parts of the sheet.

[0100]

[0101] Experimental Example 3: Optical Microscope Observation

[0102] Comparative examples 2-1 and 2-5 and examples 2-1 and 2-2 were observed using an optical microscope (Olympus DSX-CB), and the corresponding photographs are shown in Fig. 2.

[0103] The sheet of Comparative Example 2-1 has relatively small and uniformly formed bubbles (pores), and these small and uniform bubbles can increase the surface area and increase the drying efficiency.

[0104] When looking at the vertical cross-section (72X) of the sheet of Comparative Example 2-5, the bubbles were relatively large and formed unevenly. In addition, when looking at the vertical cross-section (241X) of the sheet of Comparative Example 2-5, the bubbles were large and deep and formed with a loose surface, which caused the low tensile strength.

[0105] It was confirmed that the sheets of Examples 2-1 and 2-2 had relatively smaller and more uniform bubbles than the comparative examples, thereby increasing the surface area within the sheet and improving drying efficiency.

[0106]

[0107] Experimental Example 4: Evaluation of the physical properties of sheet-type bleach according to the content of plasticizer.

[0108] According to the manufacturing method below, Comparative Examples 3-1 to 3-3 were manufactured by varying the content of plasticizer as shown in Table 5 below.

[0109] Manufacturing method:

[0110] (1) Each component was dissolved in water at 60°C according to the weight ratio described in Table 5 below, and a final mixture solution having a water content of 48 wt% was prepared.

[0111] (2) The mixture was applied to the release paper at a thickness of 1.5 mm using a comma cutter.

[0112] (3) After drying in a 125℃ oven for 10 minutes, the sheet manufacturing was completed.

[0113] Example 2-2 Comparative Example 3-1 Comparative Example 3-2 Comparative Example 3-3 PVA (MW 22,000) Saponification (mol%) 88888888 Composition (wt% based on sheet dry weight) PVA 2 5 26.0 25.4 23.7 SLS 4 85 0.04 8.8 4 5.8 Laureth-7 6 6.3 6.15.8 Citric acid 10 10.4 10.19.5 Sodium citrate 7 7.3 7.16.7 Glycerin (Plasticizer) 4 02.5 8.5 Total 100 100 100 100 Sheet formulation OX △ △

[0114] In the above Comparative Example 3-1, clumping occurred during manufacturing, making it difficult to manufacture the mixing solution. In addition, as seen in the above Comparative Example 3-2, when the content of the plasticizer was less than 3 wt% based on the dry weight of the sheet-type bleach, the flexibility of the sheet was reduced and it broke. In addition, as seen in the above Comparative Example 3-3, when the content of the plasticizer was more than 8 wt% based on the dry weight of the sheet-type bleach, it was easily bent, vulnerable to moisture, and sticky, so that the formulation was not properly performed. On the other hand, in the above Example 1, the sheet did not tear when separated from the release paper, and its physical properties were maintained well.

[0115]

[0116] <Sheet Formulation Evaluation Method>

[0117] The sheet formulation evaluation was evaluated based on the degree of separation from the release paper immediately after drying the sheet and the change in the physical properties of the sheet after a certain period of time (1 day at room temperature).

[0118] X: Sheet tears when separated from the release paper

[0119] △: When separated from the release paper, the sheet does not tear, but after a certain period of time, the sheet is denatured. For example, after a certain period of time (1 day RT), the flexibility decreases rapidly and breaks (when there is little plasticizer), or the flexibility increases rapidly and it bends easily and becomes sticky (when there is a lot of plasticizer).

[0120] ○: When separated from the release paper, the sheet does not tear and its physical properties are maintained.

[0121]

[0122] Experimental Example 5: Evaluation of physical properties when inorganic compounds are included in sheet-type bleach.

[0123] As in Experimental Example 2, a sheet-type bleach of Comparative Example 4-1 was prepared, additionally containing talc, with the composition described in Table 6 below. In addition, the physical properties of Comparative Example 4-1 were evaluated as in Experimental Example 2, and are shown in Table 6 below.

[0124] Comparative Example 4-1 PVA (MW 22,000) Saponification (mol%) 88 Composition (wt% based on sheet dry weight) PVA 25 SLS 37 laureth-7 6 citric acid 10 sodium citrate 7 talc 15 Total 100

[0125] The above talc used is Micro Talc ACE P-3 (manufacturer: NIPPON TALC), and its CAS number is: 14807-96-6.

[0126] Experimental results pH Width (cm) Length (cm) Thickness (cm) Thickness increase rate (%) Weight (g) Density (g / cm 3 )Tensile strength (N / m)2 ) Sheet Formulation Drying Efficiency Comparison Example 4-15.342.560.2330.350.18658,0004◎

[0127] The sheet manufactured with the mixture of Comparative Example 4-1 above did not stretch or have any undried areas, demonstrating excellent sheet formulation and drying efficiency (Fig. 3). However, when the sheet of Comparative Example 4-1 was dissolved in water at a concentration of 1 g / 1000 L, it did not completely dissolve due to the talc and remained cloudy, indicating poor solubility (Fig. 4). Considering that general detergents or bleaches should not leave residues after washing, the sheet of Comparative Example 4-1 containing talc was not suitable as a laundry product.

Claims

1. A sheet-type bleach containing organic acids, organic acid salts, and water-soluble polymers.

2. In paragraph 1, the organic acid includes at least one selected from the group consisting of citric acid, lactic acid, acetic acid, formic acid, and oxalic acid. The above organic acid salt is a sheet-shaped bleaching agent comprising at least one of an inorganic salt and an organic salt of the above organic acid.

3. A sheet-shaped bleaching agent according to claim 1 or 2, wherein the weight ratio of the organic acid and the organic acid salt is 10:1 to 1:1 (organic acid:organic acid salt).

4. A sheet-type bleaching agent in paragraph 1, wherein the organic acid and organic acid salt are contained in an amount of 3 to 40 wt% relative to the total weight of the sheet-type bleaching agent.

5. In the first paragraph, the water-soluble polymer is a sheet-shaped bleaching agent comprising at least one selected from the group consisting of polyvinyl alcohol, a polyvinyl alcohol copolymer, gelatin, pectin, dextran, hyaluronic acid, collagen, agar, gum arabic, acacia gum, alginic acid, sodium alginate, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, starch, dextrin, carboxymethyl starch, polyvinylpyrrolidone, polyvinyl methacrylate, polyacrylic acid, and polyethylene oxide.

6. In the fifth paragraph, the water-soluble polymer comprises polyvinyl alcohol, and the polyvinyl alcohol is a sheet-shaped bleaching agent comprising polyvinyl alcohol having a degree of saponification of 75 mol% or more.

7. A sheet-type bleaching agent in accordance with paragraph 1, wherein the water-soluble polymer is included in an amount of 15 to 60 wt% relative to the total weight of the sheet-type bleaching agent.

8. A sheet-shaped bleaching agent in paragraph 1, wherein the weight ratio of organic acid and organic acid salt: water-soluble polymer is 1:1 to 1:10 (organic acid and organic acid salt: water-soluble polymer).

9. In the first paragraph, the sheet-shaped bleaching agent is a sheet-shaped bleaching agent that substantially does not contain an inorganic compound.

10. In the first paragraph, the sheet-shaped bleaching agent further comprises a plasticizer.

11. A sheet-type bleaching agent in claim 10, wherein the plasticizer is included in an amount of 3 to 8 wt% based on the total weight of the sheet-type bleaching agent.

12. A sheet-type bleaching agent in the first paragraph, wherein the pH of the sheet-type bleaching agent is 6 or less.

13. In the first paragraph, the sheet-shaped bleaching agent has a sheet thickness of 0.05 to 0.5 cm. 14.(s1) A step of dissolving organic acids, organic acid salts, and water-soluble polymers in water; and (s2) A method for producing a sheet-type bleach, comprising the step of producing the above-mentioned dissolved mixture into a sheet of a certain thickness and then drying it.

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