Soluble laundry sheet comprising polyol or metal ion chloride

Abstract

To provide a laundry sheet soluble in water that is improved in the formulation stability, the storage stability and the sheet solubility.SOLUTION: The present invention provides a water-soluble laundry sheet formed to contain a laundry detergent ingredient, a water-soluble film-forming polymer and an alkali builder, where the laundry sheet comprises any one or more selected from the group consisting of polyols and metal ion chlorides.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a water-soluble laundry sheet that is soluble in water, and more particularly to a water-soluble laundry sheet that is soluble in water and has improved storage stability, solubility and / or detergency. This application claims priority to Korean Patent Application No. 10-2019-0062786 filed on May 28, 2019, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0002] Liquid detergents are relatively heavy and inconvenient to use, and powder detergents have the problem of scattering powder during use, so there is a continuous demand for new forms of detergent. Sheet-type laundry detergents that dissolve in wash water are available on the market, which overcome the shortcomings of powder detergents, liquid detergents, etc. Sheet-type laundry detergents have the advantages of being thin, light, and easy to store. However, problems with the cleaning power of sheet-type laundry detergents have been pointed out frequently.

[0003] To manufacture a sheet-type laundry detergent, a formulation agent must be included. However, if the amount of laundry ingredients is increased to improve the washing power, the amount of formulation agent used is reduced, and if the amount of formulation agent used to make a sheet-type laundry detergent is increased, the amount of laundry ingredients used is reduced. Therefore, it has not been easy to achieve both washing power and formulation in the industry. In addition, if the amount of laundry ingredients is increased to improve washing power, there is a problem that the storage stability of the laundry sheet is negatively affected.

[0004] In the case of water-soluble sheet-type laundry detergents that maintain their shape through formulation agents, the amount of laundry ingredients (e.g., surfactants, etc.) that can be carried is limited, so they contain more cleaning auxiliary ingredients and other ingredients that help improve cleaning power in order to improve cleaning power.Recognizing that an increase in the amount of such cleaning auxiliary ingredients can have a negative effect on the storage stability of water-soluble laundry sheets, we have conducted extensive research to improve this.

[0005] To improve cleaning power, water-soluble laundry sheets must contain more active ingredients, but increasing the amount of active ingredients can reduce the storage stability of the water-soluble laundry sheets. Therefore, we have conducted research for many years to produce sheets that have an increased content of active ingredients while still having excellent storage stability and that are easy to formulate with a small amount of formulation agent.

[0006] During washing, the speed at which a detergent dissolves in the wash water affects its cleaning power. In particular, in the case of sheet-type detergents containing formulation agents, the solubility is low, so the dissolution rate in the wash water is slow and sufficient cleaning substances cannot be provided within the washing time, resulting in a decrease in cleaning power. Summary of the Invention [Problem to be solved by the invention]

[0007] In order to solve the above problems, an object of the present invention is to provide a water-soluble laundry sheet having improved storage stability and / or dissolution rate.

[0008] Another object of the present invention is to provide a water-soluble laundry sheet that can be easily formulated with a small amount of formulation agent while maintaining or increasing the amount of the active ingredient.

[0009] It is another object of the present invention to provide a laundry sheet that has improved cleaning power and sufficient tensile strength for mass production.

[0010] Another object of the present invention is to provide a water-soluble laundry sheet in which a water-soluble film-forming polymer is solidified into a film, in which laundry detergent ingredients are distributed among the water-soluble film-forming polymer chains, and to provide a water-soluble laundry sheet in a form that further contains a polyol in addition to the water-soluble film-forming polymer. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention provides a water-soluble laundry sheet comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, the water-soluble laundry sheet further comprising a polyol and / or a metal ion chloride. The water-soluble film-forming polymer can be used as a formulation agent for the water-soluble laundry sheet.

[0012] The present inventors were the first to recognize the problem of improving the storage stability of sheet-type laundry detergents while improving the detergency of water-soluble laundry sheets, and have provided a solution to this problem. The present inventors have confirmed that by including a polyol in a water-soluble laundry sheet, the amount of cleaning ingredients in the sheet can be increased while improving storage stability, and that suitable physical properties that allow mass production can be achieved, thereby completing the present invention.

[0013] The term "laundry sheet" as used herein is understood in the art to mean a laundry product in the form of a thin film or layer in the form of a handkerchief. The laundry sheet can be prepared from a solution in which a water-soluble polymer that dissolves in water and a laundry detergent component are mixed, and the preparation method is not particularly limited. The laundry sheet is prepared using a formulation agent to form the laundry sheet into a sheet form, and the formulation agent can preferably be a water-soluble film-forming polymer that dissolves in water.

[0014] The water-soluble laundry sheet may include a film-forming water-soluble polymer. The film-forming water-soluble polymer may be one or more selected from natural, semi-synthetic, and synthetic polymers, and preferably polyvinyl alcohol (PVA) or a polyvinyl alcohol-based copolymer may be used as a formulation agent. Even if a large amount of a high content of a laundry active ingredient such as a surfactant is contained in the matrix formed by the polyvinyl alcohol or polyvinyl alcohol-based copolymer, the physical properties such as the tensile strength of the film may be maintained, and a relatively large amount of surfactant may be contained per unit area within the physical property limits required for a sheet-type detergent. In the laundry sheet of the present invention, particularly, among polyvinyl alcohols or polyvinyl alcohol-based copolymers having various molecular weights and saponification degrees, when comprehensively considering film formulation, solubility, ease of manufacture, storage stability, cleaning performance, tensile strength of the sheet, mass productivity, etc., a polymer having a number average molecular weight of 10,000 to 100,000 is preferable, a polymer having a number average molecular weight of 20,000 to 50,000 is more preferable, and a polymer having a number average molecular weight of 20,000 to 30,000 is even more preferable. The degree of saponification may be 65 to 95%, preferably 68 to 90%, and more preferably 70 to 85%. If the degree of saponification is less than 65% or more than 95%, the solubility may be low and difficult to dissolve in water, or the physical properties may be insufficient. In another embodiment, the polyvinyl alcohol-based copolymer may include a polyvinyl alcohol-based copolymer containing an anionic monomer unit having a carboxy group, and such a copolymer includes a vinyl alcohol monomer unit and an anionic monomer unit of the following chemical formula 1 or 2, and the content of the anionic monomer unit is particularly preferably 0.5 to 5 mol%.

[0015] [ka]

[0016] In Chemical Formulas 1 and 2, R1, R2, and R3 are each independently H or methyl, and n is each independently an integer of 0 to 3.

[0017] The present invention may use a wide variety of surfactants, such as nonionic surfactants, anionic surfactants, and amphoteric surfactants, as a laundry detergent ingredient to provide a laundry effect. Preferably, the detergent ingredient is RSO4-M + The surfactant may be any one or more selected from the group consisting of alkyl sulfate having 8 to 18 carbon atoms and represented by the chemical formula (wherein M is an alkali metal, preferably sodium or potassium, and most preferably sodium), more preferably α-olefin sulfonate, sodium lauryl sulfate, sodium lauryl ethoxylated sulfate, sec-alkanesulfonate, and methyl ester sulfonate, and most preferably sodium lauryl sulfate surfactant. The surfactant is preferable in terms of usability with the film-forming water-soluble polymer, cleaning power, and sheet stability.

[0018] The cleaning component may further include a nonionic surfactant or an amphoteric surfactant. The nonionic surfactant may include, but is not limited to, polyoxyalkylene alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, cocamide monomethylamine, cocamide dimethylamine, cocamide monoethylamine, fatty acid alkanolamine, amine oxide, alkyl polyglucoside, methyl polyethylene alkyl ether, or sugar ether, which may be used alone or in a mixture of two or more. In particular, it is preferable to use a polyoxyalkylene alkyl ether represented by the following chemical formula 3 or a polyoxyalkylene alkyl phenyl ether represented by the following chemical formula 4.

[0019] [Chemical formula 3] C m -H 2m+1 -O-(CH2CH2O) n -H [Chemical formula 4] Cm H 2m+1 C6H5-O-(CH2CH2O) n -H

[0020] In Chemical Formula 3 and Chemical Formula 4, m is an integer of 5 to 21, and n is an integer of 1 to 20.

[0021] The amphoteric surfactant may be, but is not limited to, amine oxide, cocamidopropyl betaine, etc., which may be used alone or in a mixture of two or more thereof.

[0022] The inventors of the present invention have confirmed that, in the case of a laundry sheet containing the water-soluble film-forming polymer and the cleaning ingredient, an alkali builder is used to improve cleaning power because the amount of laundry detergent used during washing is small, but that interactions between the ingredients used together cause problems such as reduced storage stability and reduced cleaning power, and have made efforts to improve this. The alkali builder can increase the cleaning power of the cleaning ingredients contained therein and can act as a sequestering agent or chelating agent, a buffer, a diluent or filler, a carrier, or a pH adjuster.

[0023] The laundry sheet according to the present invention may further contain cleaning auxiliary components to improve cleaning performance or formability without impairing the formulation, storage stability, ease of manufacture, etc. of the sheet. For example, the laundry sheet may further contain fluorescent whitening agents; enzymes (e.g., cellulase, protease, etc.); fabric softeners (e.g., quaternary ammonium salt-based cationic surfactants, silicone fabric softening components); bleaches (e.g., perborates, percarbonates, perphosphates, diacyl, tetraacyl peroxides); dispersants / emulsifiers (e.g., polyoxyalkylene alkyl phenyl ethers, polyoxyalkylene alkyl ethers, polyoxyethylene polyoxypropylene block polymers); germicides / disinfectants (e.g., sodium hypochlorite, hydrogen peroxide, urea peroxide); fragrances; preservatives; colorants; antibacterial agents, etc.

[0024] In one embodiment, the water-soluble laundry sheet includes a water-soluble film-forming polymer, the cleaning ingredient, and an alkali builder, and the water-soluble film-forming polymer may be included in an amount of 18 to 38 wt %, preferably 19 to 35 wt %, based on the total weight of the water-soluble laundry sheet after drying. If the content of the water-soluble film-forming polymer is high, the content of the active ingredient for the washing effect cannot be increased, and if the content of the water-soluble film-forming polymer is too low, it is difficult to formulate into a sheet. When the content is within the above range, the sheet has excellent storage stability, formulation, cleaning power and / or solubility, and has physical properties or tensile strength suitable for mass production.

[0025] In one embodiment of the present invention, when the content of the water-soluble film-forming polymer is as described above, the cleaning ingredient may be contained in an amount of 30-60% by weight, preferably 40-57% by weight, more preferably 43-55% by weight, based on the total weight of the water-soluble laundry sheet after drying. If the content of the cleaning ingredient is too high, the formulation and storage stability of the sheet may be poor, and the cleaning power may decrease compared to immediately after initial production, and if the content of the cleaning ingredient is too low, the desired cleaning effect may not be obtained. When the content is within the above range, the object of the present invention can be easily achieved.

[0026] The water-soluble laundry sheet of the present invention contains an alkali builder, which may be at least one selected from the group consisting of sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium metasilicate, alkaline sodium silicate, neutral sodium silicate, sodium tripolyphosphate, sodium pyrophosphate, sodium borate, sodium aluminosilicate, sodium sesquicarbonate, monoethanolamine (MEA) and triethanolamine (TEA), and is preferably sodium carbonate. The type of alkali builder is not particularly limited as long as it is an alkali builder commonly used in the laundry detergent manufacturing industry. The alkali builder may be contained in an amount of 1 to 20% by weight, preferably 5 to 20% by weight, more preferably 5 to 10% by weight, based on the total weight of the water-soluble laundry sheet after drying.

[0027] The polyol may include at least one selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol, and preferably includes sorbitol. The polyol may be included in an amount of 5 to 20 wt %, preferably 10 to 20 wt %, more preferably 12 to 18 wt %, and even more preferably 13 to 17 wt %, based on the total weight of the water-soluble laundry sheet after drying. When the content is within the above range, the sheet can have improved storage stability, formulation, detergency, and / or solubility, as well as physical properties and tensile strength suitable for mass production.

[0028] It is believed that the polyol reduces the reactivity of polyvinyl alcohol to improve the storage stability of the sheet and increase the possibility of formulation into the sheet, but is not necessarily limited to such a theory.

[0029] The water-soluble laundry sheet according to one embodiment of the present invention may contain the film-forming water-soluble polymer and the polyol in a ratio of 1.1:1 to 8:1, preferably 1:2 to 8:1, and more preferably 1:3 to 7:1. If the ratio exceeds the above range, problems may occur in stability and formulation.

[0030] In one embodiment of the present invention, a chloride may be further included to improve the solubility of the water-soluble laundry sheet, and the chloride may be any one or more selected from the group consisting of chlorides of group 1 or 2 metals, preferably chlorides of Na, Mg, and Ca elements, and more preferably NaCl. By further including a chloride in the water-soluble laundry sheet containing the polyol, the laundry sheet can be dissolved more quickly in wash water. The chloride may be included in an amount of 3 to 7 wt %, preferably 4 to 6 wt %, based on the total weight of the water-soluble laundry sheet after drying, and the chloride may be included in the same amount as the amount of polyol used. When the content is within the above range, the solubility of the water-soluble laundry sheet containing the polyol can be effectively improved.

[0031] One embodiment of the present invention provides a water-soluble laundry sheet that can be mass-produced while containing a small amount of formulation agent. The water-soluble laundry sheet has a water-soluble ... 2 Laundry sheets made with a small amount of formulation agent tend to be difficult to maintain their shape or to break when peeled from the release paper and wound into a roll during mass production, but the laundry sheet of the present invention having the above tensile strength is less likely to break when wound into a roll, making it advantageous for mass production.

[0032] According to one embodiment of the present invention, when the water-soluble laundry sheet contains only a metal ion chloride without a polyol, the metal ion chloride may be contained in an amount of 1 to 12 wt %, preferably 2 to 10 wt %, more preferably 3 to 10 wt %, and even more preferably 5 to 10 wt % based on the total weight of the water-soluble laundry sheet after drying. When the amount is within the above range, it is advantageous to achieve the object of the present invention and helps to improve the storage stability, formulation, cleaning power, and solubility of the sheet. In particular, the sheet containing the metal ion chloride has excellent storage stability, a high dissolution rate in water, and excellent washing effect.

[0033] According to an embodiment of the present invention, the composition may further include a polyol together with the metal ion chloride. The polyol may include at least one selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol, and preferably includes sorbitol. The polyol may be included in an amount of 5 to 20 wt %, preferably 10 to 20 wt %, more preferably 12 to 18 wt %, and even more preferably 13 to 17 wt %, based on the total weight of the water-soluble laundry sheet after drying. When the content is within the above range, the storage stability, formulation property, detergency, and / or solubility of the sheet may be improved.

[0034] It is believed that the polyol reduces the reactivity of polyvinyl alcohol to improve the storage stability of the sheet and increase the possibility of formulation into the sheet, but is not necessarily limited to such a theory.

[0035] According to one embodiment of the present invention, a laundry sheet is provided comprising a laundry detergent component, a water-soluble film-forming polymer, a metal ion chloride, and an alkali builder. The laundry detergent component is contained in an amount of 30 to 60% by weight based on the total weight of the water-soluble laundry sheet after drying, The water-soluble film-forming polymer is polyvinyl alcohol or a polyvinyl alcohol-based copolymer, and is included in an amount of 18 to 38% by weight based on the total weight of the water-soluble laundry sheet after drying; The metal ion chloride is contained in an amount of 1 to 10% by weight based on the total weight of the water-soluble laundry sheet after drying, The alkali builder may be included in an amount of 1 to 20% by weight based on the total weight of the water-soluble laundry sheet after drying.

[0036] The water-soluble laundry sheet according to the present invention may be prepared by dissolving all ingredients required for preparation in a solvent to prepare a liquid formulation, and then evaporating the solvent. The solvent may be any solvent commonly used in the art, and may be preferably water.

[0037] According to one embodiment of the present invention, a laundry sheet is provided comprising a laundry detergent component, a water-soluble film-forming polymer, a polyol, and an alkali builder. The laundry detergent component is contained in an amount of 30 to 60% by weight based on the total weight of the water-soluble laundry sheet after drying, The water-soluble film-forming polymer is polyvinyl alcohol or a polyvinyl alcohol-based copolymer, and is included in an amount of 18 to 38% by weight based on the total weight of the water-soluble laundry sheet after drying; The polyol is contained in an amount of 5 to 20% by weight based on the total weight of the water-soluble laundry sheet after drying, The alkali builder may be included in an amount of 1 to 20% by weight based on the total weight of the water-soluble laundry sheet after drying.

[0038] The water-soluble laundry sheet according to the present invention may be prepared by dissolving all ingredients required for preparation in a solvent to prepare a liquid formulation, and then evaporating the solvent. The solvent may be any solvent commonly used in the art, and may be preferably water.

[0039] The water-soluble laundry sheet according to the present invention has a dissolution rate of 3 minutes or less, preferably 30 seconds or less, as evaluated by the Examples described below. The surprising dissolution rate of the present invention allows the laundry sheet to exhibit a more excellent cleaning power than conventional laundry sheets.

[0040] The thickness of the laundry sheet according to the present invention is preferably 1 μm to 1 cm, more preferably 5 μm to 0.5 cm, and most preferably 50 μm to 1.5 mm. If the thickness of the dried laundry sheet is less than 1 μm, the active ingredient is not sufficiently supported, the strength of the film is weak, and it is difficult to obtain the desired performance. Also, if the thickness of the dried laundry sheet exceeds 1 cm, dissolution may be slowed down, resulting in a decrease in cleaning performance.

[0041] The water-soluble laundry sheet of the present invention may include a bubbling process, and through the bubbling process, the water-soluble laundry sheet may include bubbles within the sheet and / or on the sheet surface.

[0042] The laundry sheet of the present invention can be used in a state where two or more layers are integrated together by laminating another layer of sheet in addition to the one layer of the present invention.

[0043] The laundry sheet of the present invention may further comprise laundry auxiliary ingredients such as enzymes, bleaching agents, bleach activators, builders, etc., and the laundry auxiliary ingredients may be prepared in a granular form and contained within and / or on the surface of the sheet.

[0044] The present invention provides a new, hitherto unknown use of a polyol, preferably sorbitol, for improving the storage stability, solubility, and / or tensile strength of a water-soluble laundry sheet, which may further include a metal ion chloride.

[0045] The present invention provides a new use for improving storage stability, solubility, etc. of a water-soluble laundry sheet of a metal ion chloride, preferably sodium chloride, which has not been known until now. The use may further include a polyol.

[0046] The present invention provides a method for producing a water-soluble laundry sheet comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, the method further comprising adding a polyol, preferably sorbitol, during the production process of the laundry sheet, thereby improving the storage stability of the water-soluble laundry sheet, improving the solubility, and providing a method for producing the water-soluble laundry sheet having physical properties that are easy to mass-produce. The method may further include a metal ion chloride.

[0047] The present invention provides a new method for producing a water-soluble laundry sheet comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, which can improve storage stability and solubility of the water-soluble laundry sheet by adding a metal ion chloride, preferably sodium chloride, during the manufacturing process of the laundry sheet. The method can further include a polyol. Effect of the Invention

[0048] The water-soluble laundry sheet according to the present invention has excellent detergency since it is possible to inhibit the reaction between the alkali builder and PVA, thereby maintaining the function of the alkali builder and minimizing the denaturation of PVA.

[0049] The laundry sheet according to the present invention has excellent storage stability and shape retention. In addition, the present invention provides a water-soluble laundry sheet that has excellent tensile strength while using a small amount of formulation agent and is easy to mass-produce.

[0050] The laundry sheet of the present invention has excellent solubility, and the detergent components dissolve quickly in the wash water, resulting in excellent cleaning power. [Brief description of the drawings]

[0051] [Figure 1] This is a diagram to explain the method for evaluating the formulation of a soluble sheet. After drying, the sheet is stuck to the release paper and appears difficult to peel off. [Diagram 2] FIG. 1 is a diagram for explaining a method for evaluating the formulation of a soluble sheet, showing how the sheet breaks when peeled off from the release paper after drying. [Diagram 3] [Figure 3a] Evaluation of the stability of a soluble sheet over time, showing the change in soda ash content immediately after production (b) and after storage at room temperature for four weeks (a) when sorbitol was not added. After four weeks, a difference in content occurred (Comparative Example 1). [Figure 3b] Results of checking whether the storage stability of a water-soluble sheet produced according to Example 8 of the present invention could be improved. Results were checked immediately after production (b) and after storage at room temperature for four weeks (a), confirming that the addition of sorbitol can prevent the decomposition of soda ash (sodium carbonate). [Figure 3c] Results of improving sheet stability according to sorbitol content. The two arrows indicate the peaks of soda ash. This shows that the addition of sorbitol prevents the decomposition of soda ash and enhances the thermal stability of the sheet detergent. [Figure 4] The results show a comparison of cleaning power with and without sorbitol. It can be seen that the cleaning power of sheets that do not contain sorbitol drops significantly after 4 weeks. The results show a comparison of storage stability over a 4-week period. [Diagram 5] 1 shows the results of evaluating the solubility of a sheet containing sorbitol. [Figure 6] 1 shows the results of evaluating the cleaning power of soluble sheets. From the left, Comparative Example 1, Example 8, Example 9, and Example 10. [Figure 7] These are the results of checking the IR peaks of the blended liquid for producing sheets that contain sodium chloride (salt) and those that do not. (a) is salt-free, and (b) is when 5% salt is included. The presence of salt changes the size of the peaks of the active ingredients in the laundry. [Figure 8][Figure 8a] Comparison of storage stability over 4 weeks for sheets with different salt contents. Sheets containing 5% by weight of salt have better storage stability. [Figure 8b] (c) shows the initial value, and (d) shows the value after 4 weeks. As the salt content increases, the difference between (c) and (d) decreases, suggesting that the smaller the difference, the more improved the stability. [Figure 9] The results show the results of evaluating the solubility of a sheet containing salt (lower row, Example 13) and a sheet not containing salt (upper row, Comparative Example 9). The sheet containing salt in the upper row has better solubility. In all IR graphs, the vertical axis shows transmittance % and the horizontal axis shows wave numbers (cm-1). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] The present invention will be described in detail below with reference to examples to aid in the understanding of the present invention. However, the examples of the present invention can be modified into many other forms, and the scope of the present invention should not be construed as being limited by the following examples. The examples of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Temperatures used in the present specification are in degrees Celsius unless otherwise specified. In the following examples, PVA used was JR-05 product manufactured by Japan Vinyl Acetate & Poval Co., Ltd. The saponification degree was 72% and the polymerization degree was 500. Other components used were commercially available components and were obtained from the manufacturers.

[0053] 1. Preparation of soluble sheets containing polyol <Production of soluble sheet containing sorbitol> The blend is prepared by adding the following to 60°C water in the order of formulation agent (water-soluble film-forming polymer) → polyol → cleaning ingredients → cleaning auxiliary ingredients → others, and stirring at 180 RPM until each addition step is completely dissolved. The amount of water is the same as the sum of formulation agent + polyol + cleaning ingredients + cleaning auxiliary ingredients + others (50% aqueous solution). In the tabletting process, the formulated solution was made into a sheet with a size of 15×25 cm and a thickness of 1.5 mm using a doctor blade and dried in a drying oven at 125°C for 12 minutes.

[0054] <Evaluation of Tabletting of Water-Soluble Washing Sheet> Evaluate by the following method. Observe whether the phenomena as shown in FIGS. 1 and 2 occur after production. That is, after production, observe whether it sticks to the release paper and cannot be peeled off, and then observe whether the sheet breaks when peeled off from the release paper after drying. The evaluation was carried out in a constant temperature and humidity chamber at 20°C and 30%. It was manufactured 5 times repeatedly. If all phenomena were not observed, it was evaluated as good; if only FIG. 1 was observed, it was evaluated as bad; if both FIGS. 1 and 2 were observed, it was evaluated as very bad. As can be confirmed from the following experimental results, even when a polyol was added instead of the tabletting agent to produce a washing sheet, tabletting was possible.

[0055] <Evaluation of Stability over Time through IR> The water-soluble washing sheet manufactured using PVA has a problem that as time passes, the decomposition of the washing components and washing aid components is promoted due to the decomposition of PVA. Therefore, it was confirmed whether the storage stability was improved by further containing a polyol. The IR spectrum was confirmed for the formulated solution for the washing sheet manufactured with a 50% aqueous solution and having the following composition. IR was measured immediately after production and measured again after storage for 4 weeks (stored in a package made of PET16+LLDPE55 material at 20°C and 30%) (measurement equipment: PerkinElmer Ultra 2, temperature 20°C, humidity 30% constant temperature and humidity chamber)

[0056] Changes were observed at 1410 and 1450 cm -1 This peak corresponds to CO3 in Na2CO3. When the reaction of Na2CO3 + H2O → 2NaOH + CO2 proceeds due to the heat and moisture in contact during the storage process, CO3 2- is consumed. Therefore, the corresponding 1410 and 1450 cm 2- -1 ​It is believed that the strength of When sorbitol was present, it was possible to retard the decrease of the alkali builder Na2CO3.

[0057] These results demonstrate that the cleaning power is improved.

[0058] <Soluble sheet with improved performance using polyol (sorbitol)> Laundry sheets having the following compositions were prepared and evaluated.

[0059] [Table 1]

[0060] Experiments were performed with a variety of polyols, as shown in Table 2 below.

[0061] [Table 2]

[0062] It was confirmed that sheets manufactured using sorbitol, erythritol, and xylitol as polyols were all easy to formulate and showed effects similar to those of sorbitol. When polyol was used, the content of the formulation agent was reduced to a maximum of 23% based on the total weight of the sheet, so that the formulation agent content in the sheet was reduced, but it was easy to manufacture the sheet. The sorbitol content is less than 20% by weight and the tensile strength is 0.79 to 3.87 kgf / cm 2 It was confirmed that when the content of sorbitol is 10% by weight to 20% by weight of the entire sheet, the sheet has excellent mass production capability, and when the content of sorbitol is 10% by weight to 20% by weight of the entire sheet, the solubility is improved.

[0063] [Evaluation result 3] Change in cleaning power according to sheet storage period (sorbitol applied vs. sorbitol not applied) (storage conditions: 20°C, humidity 30%) The cleaning power of the sheets produced in Comparative Example 1 and Example 3 was compared immediately after production and after 4 weeks of storage, and the results are shown in FIG. The cleaning power was evaluated in the following manner. 1. Terg-o-tometer, 1L of water, water temperature 20℃, hardness 50ppm 2. Contaminated cloth used: Japanese wet contaminated cloth (116, 2 sheets / L), 3. Sample amount used: Standard amount is 0.09g / L 4. After placing the designated amount of contaminated cloth and sample in 1L of water, stir and evaluate for 10 minutes. (Evaluate each contaminated cloth.) 5. The Wb value of each soiled cloth was measured using a color difference meter, and the cleaning power was calculated using the Harris formula. 6. The cleaning power immediately after production is converted to 100 and the change is confirmed. *The samples were stored in a PET16+LLDPE55 packaging for 4 weeks.

[0064]

number

[0065] Here, R S is the surface reflectance of the soiled cloth before washing, and R b is the surface reflectance after washing, and R D is the surface reflectance of the white cloth. Referring to FIG. 4, the sheet containing 15 wt % sorbitol in Example 3 maintained the same detergency as when it was first manufactured even after 4 weeks of storage, whereas the sheet not containing sorbitol showed a decrease in detergency of about 40%. It is believed that when sorbitol is used, the deterioration of detergency caused by the decomposition of soda ash (sodium carbonate) is prevented by enhancing storage stability, and there is no difference in detergency between immediately after production and after storage at room temperature, but the present invention should not be interpreted as being limited to such a theory.

[0066] <Method for evaluating the dissolution rate of soluble sheets> [Evaluation method] The samples produced in the examples and comparative examples were each 6×6×0.12 cm 3 After preparing water at 25°C in a temperature and humidity controlled room with a temperature of 20°C and a humidity of 30%, a 25cm x 30cm square water tank was filled with water up to a water level of 5cm. The sample was floated on the water surface and dissolved without stirring five times, and the average time was measured. If the time to dissolve was within 30 seconds, it was rated as very good, if it was between 30 seconds and 3 minutes, it was rated as good, if it was between 3 minutes and 5 minutes, it was rated as normal, if it was between 5 minutes and 10 minutes, it was rated as poor, and if it was 10 minutes or more, it was rated as very poor. *Criteria for determining dissolution: When filtered through a 75μm filter, it was determined to be dissolved when the weight of unfiltered residual detergent was less than 5% of the total detergent weight.

[0067] The results of Comparative Example 1 and Example 3 are shown in Figure 5. When polyol was used, the dissolution rate increased significantly. The top row of Figure 5 is a photograph showing the dissolution rate of the sheet of Comparative Example 1, and the bottom row is a photograph showing the dissolution rate of the sheet of Example 3.

[0068] <Laundry sheet mass production evaluation method and standards> [Method of evaluating mass productivity] 1. After the product was dried at the factory, we checked whether it broke when peeling it off from the release paper. 2. When 800 kg of the mixed liquid was dried, if it was wound on the rewinder without breaking, it was rated as good, if it broke during rewinding, it was rated as poor, and if it broke before rewinding, it was rated as very poor.

[0069] [Method of evaluating tensile strength] 1) A sample was prepared that was 20 mm wide, 60 mm long, and 1.2 mm thick. 2) The tensile strength was measured using a 500N zwicki manufactured by ZwickRoell in a constant temperature and humidity room at 20°C and 30% humidity. 3) The distance between the grips was set to 25 mm, the sample was fixed, and the sample was moved at a speed of 500 mm / min until it broke to measure the tensile strength.

[0070] [Experimental Results] [Table 3]

[0071] 1. After measuring three times, record the average value. 2. As the sorbitol content increases, the tensile strength tends to decrease, and at a content of 20% or more, the tensile strength shows a tendency to decrease sharply. 3. With a content of 20% or less, mass production was easy without breakage during rewinding. If the sorbitol content exceeded 20%, the sheet would break during the peeling process before the rewinding process, making production impossible.

[0072] <Evaluation of the increase in active ingredients and cleaning power of soluble sheets> We investigated whether formulation is possible even with a small amount of formulation agent when using sorbitol, and whether storage stability and solubility are improved. Therefore, we investigated whether the ratio of active ingredients can be changed and the amount can be increased by using sorbitol, and the resulting change in cleaning power.

[0073] [Table 4]

[0074] [Checking changes in cleaning power] 1. Terg-o-tometer, 1L of water, water temperature 20℃, hardness 50ppm 2. Contaminated cloth used: Japanese wet contaminated cloth (JIS, 8 sheets / L), W-20D (20D, 8 sheets / L), empa-116 (116, 2 sheets / L), empa-117 (117, 2 sheets / L) 3. Sample amount used: Standard amount is 0.09g / L 4. After placing the designated amount of contaminated cloth and sample in 1L of water, stir and evaluate for 10 minutes. (Evaluate each contaminated cloth.) 5. After measuring the changed Wb value of each soiled cloth using a color difference meter, calculate the cleaning power using the Harris formula.

[0075]

number

[0076] Here, R S is the surface reflectance of the soiled cloth before washing, and R b is the surface reflectance after washing, and R D is the surface reflectance of the white cloth.

[0077] When the active ingredient was increased, the cleaning power increased by more than 10% for all stains compared to the conventional product, and the cleaning power increased by about 30% for protein stains (116 / 117). The results are shown in Figure 6.

[0078] <Solubility evaluation of water-soluble laundry sheets containing both sodium chloride and polyol> [Table 5]

[0079] When sorbitol and sodium chloride were used together, the dissolution rate improved significantly.

[0080] 2. Preparation of soluble sheets containing metal ion chlorides <Production of soluble sheet containing sodium chloride (salt)> The blend is prepared by adding the following to 60°C water in the order of formulation agent (water-soluble film-forming polymer) → polyol → cleaning ingredients → cleaning auxiliary ingredients → others, and stirring at 180 RPM until each addition step is completely dissolved. The amount of water is the same as the sum of formulation agent + polyol + cleaning ingredients + cleaning auxiliary ingredients + others (50% aqueous solution). In the formulation process, the mixed liquid was cut into a sheet of 15 x 25 cm in size and 1.5 mm in thickness using a doctor blade, and dried in a drying oven at 125°C for 12 minutes.

[0081] <Evaluation of formulations for water-soluble laundry sheets> The evaluation is carried out according to the following methods. After drying, observe whether the phenomenon shown in Figures 1 and 2 occurs. That is, observe whether the sheet sticks to the release paper after drying and cannot be peeled off, and then observe whether the sheet breaks when peeled off from the release paper after drying. The evaluation was carried out in a constant temperature and humidity chamber at 20°C and 30%. It was manufactured 5 times repeatedly. If all phenomena were not observed, it was evaluated as good; if only Figure 1 was observed, it was evaluated as bad; if both Figure 1 and Figure 2 were observed, it was evaluated as very bad.

[0082] In the water-soluble washing sheet added with metal ion chloride, there were few problems of sticking to the release paper and breaking of the sheet. That is, it was confirmed that it had a positive effect on the tablet formation of the sheet.

[0083]

Table 6

[0084] <Evaluation of stability over time through IR> The water-soluble washing sheet manufactured using PVA has a problem that as time passes, the decomposition of the washing components and washing aid components is promoted due to the decomposition of PVA. Therefore, it was confirmed whether the storage stability could be improved by further containing salt. The results are shown in Figure 7. The IR spectrum was confirmed for the formulation liquid for the washing sheet manufactured with a 50% aqueous solution and having the following composition. IR was measured immediately after production, and IR was measured again after storage for 4 weeks (stored in a package made of PET16 + LLDPE55 material at 20°C and 30%) (measurement equipment: PerkinElmer Ultra 2, temperature 20°C, humidity 70% constant temperature and humidity chamber)

[0085] From the results in Figure 7, it was confirmed that when salt was contained, the IR peak of the washing active ingredient changed. In particular, as shown in Figures 8a and 8b, when salt was contained at 5% by weight compared to the dry weight of the sheet, it was confirmed that there was almost no peak difference in the active ingredient. From such results, it can be seen that salt affects the stability of the active ingredient and improves the washing power improvement effect.

[0086] <Evaluation method for dissolution rate of soluble sheet> [Evaluation method] The samples manufactured in the examples and comparative examples were 6×6×0.12 cm 3Water at 25°C was prepared in a temperature and humidity room with a temperature of 20°C and a humidity of 70%, and then a 25cm x 30cm square tank was filled with water to a water level of 5cm. The sample was floated on the water surface and dissolved without stirring five times, and the average time was measured. If the time to dissolve was within 30 seconds, it was rated as very good, if it was between 30 seconds and 3 minutes, it was rated as good, if it was between 3 minutes and 5 minutes, it was rated as normal, if it was between 5 minutes and 10 minutes, it was rated as poor, and if it was 10 minutes or more, it was rated as very poor. *Criteria for determining dissolution: When filtered through a 75μm filter, it was determined to be dissolved if the weight of the unfiltered residual detergent was less than 5% of the total detergent weight.

[0087] The results are shown in Figure 9. It can be seen that producing a sheet containing 5% salt by weight significantly increases the dissolution rate of the laundry sheet compared to the sheet without salt.

[0088] <Improvement of dissolution rate according to the type of metal ion chloride> To determine how the solubility of laundry sheets changes depending on the type of chloride, the following experiment was carried out. The contents are shown in weight percent.

[0089] [Table 7]

[0090] Water-soluble laundry sheets having the compositions shown in Table 7 were prepared and the dissolution rates of the water-soluble laundry sheets were evaluated according to the above-mentioned <Method for Evaluating Dissolution Rate of Soluble Sheet>. When measured according to the above-mentioned method, the water-soluble laundry sheet containing sulfate (Comparative Example 12) was hardly dissolved even after 50 seconds. However, it was confirmed that the water-soluble laundry sheets containing chloride of Examples 15 to 17 were dissolved in wash water at a significantly faster rate. [Industrial Applicability]

[0091] The present invention provides a sheet-type laundry detergent that is soluble in water and can be used conveniently. The sheet-type laundry detergent according to the present invention has excellent solubility and storage stability.

Claims

1. A water-soluble laundry sheet comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, The laundry sheet is a water-soluble laundry sheet comprising at least one selected from the group consisting of polyols and metal ion chlorides.

2. 2. The water-soluble laundry sheet according to claim 1, wherein the detergent component is an alkali metal alkyl sulfate having 8 to 18 carbon atoms.

3. 3. The water-soluble laundry sheet according to claim 2, wherein the cleaning component comprises at least one selected from the group consisting of α-olefin sulfonate, sodium lauryl sulfate, sodium ethoxylated lauryl sulfate, sec-alkanesulfonate, and methyl ester sulfonate.

4. 2. The water-soluble laundry sheet of claim 1, wherein the water-soluble film-forming polymer comprises polyvinyl alcohol or a polyvinyl alcohol-based copolymer.

5. 5. The water-soluble laundry sheet according to claim 4, wherein the polyvinyl alcohol or polyvinyl alcohol-based copolymer has a number average molecular weight of 10,000 to 100,000 and a degree of saponification of 65 to 95%.

6. 2. The water-soluble laundry sheet according to claim 1, wherein the water-soluble film-forming polymer is contained in an amount of 18 to 38% by weight based on the total weight of the water-soluble laundry sheet after drying.

7. 2. The water-soluble laundry sheet according to claim 1, wherein the cleaning component is contained in an amount of 30 to 60% by weight based on the total weight of the water-soluble laundry sheet after drying.

8. 2. The water-soluble laundry sheet according to claim 1, wherein the alkali builder is at least one selected from the group consisting of sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium metasilicate, alkali sodium silicate, neutral sodium silicate, sodium tripolyphosphate, sodium pyrophosphate, sodium borate, sodium aluminosilicate, sodium sesquicarbonate, monoethanolamine, and triethanolamine.

9. 2. The water-soluble laundry sheet according to claim 1, wherein the polyol is at least one selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol.

10. 2. The water-soluble laundry sheet according to claim 1, wherein the polyol is contained in an amount of 5 to 20% by weight based on the total weight of the water-soluble laundry sheet after drying.

11. 2. The water-soluble laundry sheet according to claim 1, wherein the metal ion chloride is at least one selected from the group consisting of sodium chloride, magnesium chloride, calcium chloride, and potassium chloride.

12. 12. The water soluble laundry sheet of claim 11, wherein said metal ion chloride is sodium chloride.

13. 12. The water-soluble laundry sheet of claim 11, wherein the chloride is present in an amount of 1 to 10% by weight based on the total weight of the water-soluble laundry sheet after drying.

14. 14. The water-soluble laundry sheet of claim 13, wherein the chloride is present in an amount of 3 to 7% by weight based on the total weight of the water-soluble laundry sheet after drying.

15. The water-soluble laundry sheet has a water-soluble water-insoluble water- ... ２ 2. The water soluble laundry sheet of claim 1, having a tensile strength of

16. 2. The water-soluble laundry sheet according to claim 1, wherein at least one selected from the group consisting of polyols and metal ion chlorides is a polyol.

17. 2. The water-soluble laundry sheet according to claim 1, wherein at least one selected from the group consisting of polyols and metal ion chlorides is a metal ion chloride.

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