Dissolvable laundry sheets containing polyols or metal ion chlorides

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, and more specifically, to a water-soluble laundry sheet with improved storage stability, solubility, and / or cleaning power. This application claims priority based on Korean Patent Application No. 10-2019-0062786, filed on 28 May 2019, and all contents disclosed in the specification and drawings of said application are incorporated herein by reference. [Background technology]

[0002] Liquid detergents are inconvenient to use because they are relatively heavy, 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 commercially available, improving upon the shortcomings of powder and liquid detergents used as laundry detergents. 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 are frequently pointed out.

[0003] To manufacture sheet-type laundry detergent, a formulation agent must be included. However, increasing the amount of laundry ingredients to improve cleaning power reduces the amount of formulation agent used, and increasing the amount of formulation agent to form a sheet reduces the amount of laundry ingredients used. Therefore, achieving both cleaning power and formulation has not been easy in this industry. Furthermore, increasing the amount of laundry ingredients to improve cleaning power also creates the problem of negatively impacting the storage stability of the laundry sheets.

[0004] In the case of water-soluble, sheet-type laundry detergents whose form is maintained by a formulation agent, the amount of supported laundry components (e.g., surfactants) is limited. Therefore, to improve cleaning power, more cleaning aids and other components that enhance cleaning power are added. Recognizing that such an increase in cleaning aids can negatively affect the storage stability of water-soluble laundry sheets, we conducted various studies to improve this.

[0005] To improve cleaning power, more active ingredients must be included in water-soluble laundry sheets. However, increasing the amount of active ingredients may impair the storage stability of water-soluble laundry sheets. Therefore, we have spent many years researching how to manufacture sheets that have excellent storage stability while increasing the content of active ingredients, and that are easy to form with a small amount of formulation agent.

[0006] During laundry, the rate at which detergent dissolves in the wash water affects cleaning power. In particular, with sheet-type detergents containing formulation agents, the low solubility means that the dissolution rate in the wash water is slow, resulting in insufficient cleaning agents being provided within the washing time, which leads to a decrease in cleaning power. [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to provide a water-soluble laundry sheet with improved storage stability and / or dissolution rate in order to solve the above-mentioned problems.

[0008] Furthermore, the present invention aims to provide a water-soluble laundry sheet that can be easily formed using only a small amount of formulation agent, while maintaining or increasing the amount of active ingredients.

[0009] Furthermore, the present invention aims to provide a laundry sheet with improved cleaning power and sufficient tensile strength for mass production.

[0010] Furthermore, the present invention aims to provide a water-soluble laundry sheet in which a water-soluble film-forming polymer is solidified into a film, in which laundry cleaning components are distributed between water-soluble film-forming polymer chains, and to provide a water-soluble laundry sheet in which a polyol is further included in addition to the water-soluble film-forming polymer. [Means for solving the problem]

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

[0012] The inventors were the first to recognize the challenge of improving the storage stability of sheet-type laundry detergents while simultaneously enhancing the cleaning power of water-soluble laundry sheets, and have now come up with a solution to address this challenge. By incorporating a polyol into the water-soluble laundry sheet, the inventors were able to increase the amount of cleaning components within the sheet while improving storage stability, confirming that the sheet possesses appropriate physical properties suitable for mass production, and thus completed the present invention.

[0013] As used herein, the term “laundry sheet” is understood in the industry to mean a thin, film-like or layered laundry product in the form of a handkerchief. The laundry sheet can be manufactured from a solution of a water-soluble polymer and a laundry detergent component, and the method of manufacture is not particularly limited. A formulation agent is used to form the laundry sheet into a sheet, and preferably a water-soluble film-forming polymer can be used as the formulation agent.

[0014] The water-soluble laundry sheet may contain a film-forming water-soluble polymer. The film-forming water-soluble polymer may be selected from one or more natural, semi-synthetic, and synthetic polymers, and preferably, polyvinyl alcohol (PVA) or a polyvinyl alcohol copolymer may be used as a formulation agent. Even if a large amount of laundry active ingredients such as a high-content surfactant is included in the matrix formed by the polyvinyl alcohol or polyvinyl alcohol copolymer, the physical properties of the film, such as tensile strength, can be maintained, and a relatively large amount of surfactant per unit area can be included within the physical property limits required for sheet-type detergents. In the laundry sheet of the present invention, in particular, among polyvinyl alcohol or polyvinyl alcohol copolymers having diverse molecular weights and degrees of saponification, when considering film formulation properties, solubility, ease of manufacture, storage stability, washing performance, tensile strength of the sheet, and mass productivity, polymers with a number average molecular weight of 10,000 to 100,000 are preferred, polymers with a number average molecular weight of 20,000 to 50,000 are more preferred, and polymers with a number average molecular weight of 20,000 to 30,000 are even more preferred. The degree of saponification may be 65-95%, preferably 68-90%, and more preferably 70-85%. If the degree of saponification is less than 65% or more than 95%, the solubility may be low and it may be difficult to dissolve in water, or it may not have sufficient physical properties. In another embodiment, the polyvinyl alcohol copolymer may include a polyvinyl alcohol copolymer containing an anionic monomer unit having a carboxyl group, and such a copolymer is particularly desirable in which the content of the anionic monomer unit is 0.5-5 mol%, comprising a vinyl alcohol monomer unit and an anionic monomer unit of the following chemical formula 1 or 2.

[0015] [ka]

[0016] In chemical formulas 1 and 2, R1, R2, and R3 are independently H or methyl, and n is independently an integer between 0 and 3.

[0017] The present invention can use a variety of surfactants such as nonionic surfactants, anionic surfactants, and amphoteric surfactants as washing components for providing a washing effect. Desirably, the washing component is RSO4-M + an alkyl sulfate having 8 to 18 carbon atoms represented by the chemical formula (M is an alkali metal, desirably sodium or potassium, most desirably sodium), more desirably an α-olefin sulfonate, sodium lauryl sulfate, sodium lauryl ethoxylated sulfate, sec-alkanesulfonate, or methyl ester sulfonate, and may be any one or more selected from the group consisting of these, and most desirably may contain a sodium lauryl sulfate surfactant. The surfactant is desirable in terms of usability with a film-forming water-soluble polymer, detergency, and stability of the sheet.

[0018] As the washing component, it may further contain a nonionic surfactant or an amphoteric surfactant. Examples of the nonionic surfactant include, but are not limited to, polyoxyalkylene alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polyoxypropylene block polymer, polyethylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, cocoamidomethylamine, cocoamidodimethylamine, cocoamidoethylamine, fatty acid alkanolamine, amine oxide, alkyl polyglucoside, methyl polyethylene alkyl ether, or sugar ether, and these can be used alone or as a mixture of two or more. In particular, it is desirable 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 from 5 to 21, and n is an integer from 1 to 20.

[0021] In addition, the amphoteric surfactant is not limited to these, and there are amine oxides, cocamidopropyl betaine, etc., and these can be used alone or as a mixture of two or more.

[0022] The inventors of the present invention, in the case of the laundry sheet containing the water-soluble film-forming polymer and the cleaning component, since the amount of the laundry detergent used during washing is small, an alkali builder is used to improve the detergency. However, it has been confirmed that problems such as a decrease in storage stability and a decrease in detergency occur due to the interaction between the components used together, and efforts have been made to improve it. The alkali builder can increase the washing ability of the contained cleaning component and can act as a sequestering agent or chelating agent, buffer, diluent or filler, carrier or pH regulator.

[0023] The laundry sheet according to the present invention may further contain a cleaning aid component in order to improve the cleaning performance or forming ability within a range that does not inhibit the tabletability, storage stability, ease of manufacture, etc. of the sheet. For example, a fluorescent whitening agent; an enzyme (e.g., cellulase, protease, etc.); a fabric softener (e.g., a quaternary ammonium salt-based cationic surfactant, silicone-based fabric softening component); a bleaching agent (e.g., perborate, percarbonate, perphosphate, diacyl, tetraacyl peroxide); a dispersant / emulsifier (e.g., polyoxyalkylene alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyethylene polyoxypropylene block polymer); a bactericidal / disinfectant (e.g., sodium hypochlorite, hydrogen peroxide, urea peroxide); a fragrance; a preservative; a pigment; an antibacterial agent, etc. may be further contained.

[0024] In one embodiment, the water-soluble laundry sheet comprises a water-soluble film-forming polymer, the cleaning component, and an alkali builder, wherein the water-soluble film-forming polymer is present in an amount of 18 to 38% by weight, preferably 19 to 35% by weight, relative to the total weight of the water-soluble laundry sheet after drying. If the content of the water-soluble film-forming polymer is too 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 form the sheet into a dosage form. When the content is within the above range, the sheet may have excellent storage stability, dosage formability, washing power and / or solubility, and 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 component may be contained in an amount of 30 to 60% by weight, preferably 40 to 57% by weight, and more preferably 43 to 55% by weight, relative to the total weight of the water-soluble laundry sheet after drying. If the content of the cleaning component is too high, the formulation properties and storage stability of the sheet will be poor, and the cleaning power will decrease compared to immediately after initial production. If the content of the cleaning component is too low, the desired cleaning effect may not be achieved. 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 one or more 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 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 present in an amount of 1 to 20% by weight, preferably 5 to 20% by weight, and more preferably 5 to 10% by weight, relative to the total weight of the water-soluble laundry sheet after drying.

[0027] The polyol may contain one or more selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol, and preferably sorbitol. The polyol may be present in an amount of 5 to 20% by weight of the total weight of the water-soluble laundry sheet after drying, preferably 10 to 20% by weight, more preferably 12 to 18% by weight, and even more preferably 13 to 17% by weight. When the content is within the above range, the storage stability, dosage form, washing power and / or solubility of the sheet may be improved, and the sheet may have physical properties and tensile strength suitable for mass production.

[0028] While the aforementioned polyol is thought to reduce the reactivity of polyvinyl alcohol, thereby improving the storage stability of the sheet and increasing its suitability for formulation into a sheet, the theory is not necessarily limited to this.

[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 in a ratio of 1:2 to 8:1, and more preferably in a ratio of 1:3 to 7:1. If the ratio exceeds the above, problems with stability and dosage form may occur.

[0030] One embodiment of the present invention may further contain a chloride to improve the solubility of the water-soluble laundry sheet, the chloride being one or more selected from the group consisting of chlorides of Group 1 or Group 2 metals, preferably containing chlorides of elements Na, Mg, and Ca, and more preferably NaCl. By further containing a chloride in the water-soluble laundry sheet containing the polyol, the laundry sheet can be dissolved in the laundry water more quickly. The chloride may be present in an amount of 3 to 7% by weight, preferably 4 to 6% by weight, based on the total weight of the water-soluble laundry sheet after drying, and may contain the same amount of chloride 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 viscosity of 0.79 to 3.8 kgf / cm² when measured at 25°C using a ZwickRoell 500N Zwicki measuring instrument. 2 It can have a tensile strength of [value missing]. Laundry sheets manufactured with a small amount of formulation agent are difficult to maintain their shape, or are prone to breaking when rolled up while peeling them from the release paper during mass production. However, the laundry sheet of the present invention, having the tensile strength described above, is less likely to break when rolled up and is advantageous for mass production.

[0032] According to one embodiment of the present invention, when the water-soluble laundry sheet contains only metal ion chloride without polyol, the metal ion chloride may be present in an amount of 1 to 12% by weight, preferably 2 to 10% by weight, more preferably 3 to 10% by weight, and even more preferably 5 to 10% by weight, relative to the total weight of the water-soluble laundry sheet after drying. When the content is within the above range, it is advantageous for achieving the objectives of the present invention and helps to improve the storage stability, dosage form, cleaning power, and solubility of the sheet. In particular, sheets containing metal ion chloride have excellent storage stability, dissolve quickly in water, and have superior washing effect.

[0033] According to one embodiment of the present invention, the metal ion chloride may further contain a polyol. The polyol comprises one or more selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol, and preferably contains sorbitol. The polyol may be present in an amount of 5 to 20% by weight, preferably 10 to 20% by weight, more preferably 12 to 18% by weight, and even more preferably 13 to 17% by weight, relative to the total weight of the water-soluble laundry sheet after drying. When the content is within the above range, the storage stability, dosage form, cleaning power, and / or solubility of the sheet can be improved.

[0034] While the aforementioned polyol is thought to reduce the reactivity of polyvinyl alcohol, thereby improving the storage stability of the sheet and increasing its suitability for formulation into a sheet, the theory is not necessarily limited to this.

[0035] A laundry sheet according to one embodiment of the present invention is formed comprising a laundry cleaning component, a water-soluble film-forming polymer, a metal ion chloride, and an alkali builder. The aforementioned laundry cleaning component is present in an amount of 30-60% by weight relative to the total weight of the water-soluble laundry sheet after drying. The aforementioned 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 relative to the total weight of the water-soluble laundry sheet after drying. The aforementioned metal ion chloride is present in an amount of 1 to 10% by weight relative to the total weight of the water-soluble laundry sheet after drying. The aforementioned alkali builder may be included in an amount of 1 to 20% by weight relative to the total weight of the water-soluble laundry sheet after drying.

[0036] The water-soluble laundry sheet according to the present invention can be manufactured by dissolving all the necessary components for the formulation in a solvent to produce a compounding solution, and then evaporating the solvent. The solvent can be a solvent commonly used in the industry, and is preferably water.

[0037] A laundry sheet according to one embodiment of the present invention is formed comprising a laundry cleaning component, a water-soluble film-forming polymer, a polyol, and an alkali builder. The aforementioned laundry cleaning component is present in an amount of 30-60% by weight relative to the total weight of the water-soluble laundry sheet after drying. The aforementioned 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 relative to the total weight of the water-soluble laundry sheet after drying. The polyol is present in an amount of 5 to 20% by weight relative to the total weight of the water-soluble laundry sheet after drying. The aforementioned alkali builder may be included in an amount of 1 to 20% by weight relative to the total weight of the water-soluble laundry sheet after drying.

[0038] The water-soluble laundry sheet according to the present invention can be manufactured by dissolving all the necessary components for the formulation in a solvent to produce a compounding solution, and then evaporating the solvent. The solvent can be a solvent commonly used in the industry, and is 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, according to the evaluation method of the examples described later. Due to the remarkable dissolution rate of the present invention, it can exhibit even better 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 support of the active ingredient will be insufficient, the strength of the film will be weak, and it will be difficult to obtain the desired performance. Also, if the thickness of the dried laundry sheet exceeds 1 cm, dissolution will be slow, which may reduce the washing performance.

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

[0042] The laundry sheet of the present invention can be used in a state in which two or more layers are integrated, with other layers of sheets laminated on top of a single sheet according to the present invention.

[0043] The laundry sheet of the present invention may further contain laundry aids such as enzymes, bleaches, bleach activators, and builders, and these laundry aids may be manufactured in granular form and contained within and / or on the surface of the sheet.

[0044] The present invention provides novel applications for improving the storage stability, solubility, and / or tensile strength of water-soluble laundry sheets containing polyols, preferably sorbitol, which have not been previously known. The applications may further include metal ion chlorides.

[0045] The present invention provides novel applications for metal ion chlorides, preferably sodium chloride, for improving the storage stability and solubility of water-soluble laundry sheets, which have not been previously known. These applications may further include polyols.

[0046] The present invention aims to provide a novel method for producing a water-soluble laundry sheet, comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, by adding a polyol, preferably sorbitol, during the manufacturing process of the laundry sheet. This method improves the storage stability of the water-soluble laundry sheet, enhances its solubility, and provides properties that facilitate mass production. The method may further include metal ion chlorides.

[0047] The present invention aims to provide a novel method for producing a water-soluble laundry sheet, comprising a laundry detergent component, a water-soluble film-forming polymer, and an alkali builder, by adding a metal ion chloride, preferably sodium chloride, during the manufacturing process of the laundry sheet, thereby improving the storage stability and solubility of the water-soluble laundry sheet. The method may further include a polyol. [Effects of the Invention]

[0048] The water-soluble laundry sheet according to the present invention can suppress the reaction between the alkali builder and PVA, and is expected to maintain the function of the alkali builder and minimize the modification of PVA, thus exhibiting superior cleaning power.

[0049] The laundry sheet according to the present invention has excellent storage stability and shape retention capabilities. Furthermore, the invention provides a water-soluble laundry sheet that has excellent tensile strength despite 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 its cleaning components dissolve quickly in the wash water, resulting in superior cleaning power. [Brief explanation of the drawing]

[0051] [Figure 1] This diagram illustrates a method for evaluating the formulation of a soluble sheet, showing that after drying, it adheres to the release paper and is difficult to peel off. [Figure 2] This diagram illustrates a method for evaluating the formulation of a soluble sheet, showing how the sheet breaks when peeled off the release paper after drying. [Figure 3] [Figure a] This shows the evaluation of the stability of the soluble sheet over time, showing the change in soda ash content immediately after production (b) and after storage at room temperature for 4 weeks (a) when sorbitol was not added. After 4 weeks, a difference in content occurred (Comparative Example 1). [Figure 3b] This shows the results of confirming whether the storage stability of the water-soluble sheet produced by Example 8 of the present invention could be improved. The results were confirmed immediately after production (b) and after storage at room temperature for 4 weeks (a), and it was confirmed that the decomposition of soda ash (sodium carbonate) can be prevented by adding sorbitol. [Figure 3c] This shows the results of the improvement in sheet stability according to the sorbitol content. The two arrows indicate the peak of soda ash. This shows that the decomposition of soda ash did not occur by adding sorbitol, and the thermal stability of the sheet detergent was enhanced. [Figure 4] This shows the results of a comparison of cleaning power with and without sorbitol. It can be seen that the cleaning power of the sheets without sorbitol significantly decreased after 4 weeks. The results of a comparison of storage stability over 4 weeks are also shown. [Figure 5] This shows the results of evaluating the solubility of sheets containing sorbitol. [Figure 6] This shows the results of the cleaning power evaluation of the soluble sheets. From left to right, they are Comparative Example 1, Example 8, Example 9, and Example 10. [Figure 7] This shows the results of examining the IR peaks of formulations used to manufacture sheets containing and without sodium chloride (salt). (a) represents the salt-free solution, and (b) represents the solution containing 5% salt. The presence of salt alters the magnitude of the peak for the laundry active ingredient. [Figure 8][Figure 8a] This shows the results of comparing the storage stability of the sheets over 4 weeks depending on the salt content. The storage stability of the sheets is better when they contain 5% by weight of salt. [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, and a smaller difference suggests that the stability has improved. [Figure 9] This shows the results of evaluating the solubility of sheets containing salt (bottom row, Example 13) and sheets without salt (top row, Comparative Example 9). The salt-containing sheet in the top row shows superior solubility. In all IR graphs, the vertical axis represents transmittance (%) and the horizontal axis represents wave numbers (cm-1). [Modes for carrying out the invention]

[0052] The present invention will be described in detail below, including examples, to aid in understanding 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 examples described below. The examples of the present invention are provided to give a more complete explanation of the present invention to those with average knowledge in the industry. Temperatures used herein mean °C unless otherwise specified. In the examples below, the PVA used was JR-05 product from Nippon Vitro Vinegar Co., Ltd. The degree of saponification was 72%, and the degree of polymerization was 500. Other components used were commercially available components obtained from manufacturers.

[0053] 1. Manufacturing of soluble sheets containing polyols <Manufacturing of soluble sheets containing sorbitol> The preparation of the compound solution involves adding a water-soluble film-forming polymer (formulator) → polyol → cleaning component → cleaning aid component → other components to 60°C water in that order, stirring at 180 RPM until each component is completely dissolved. At this time, the amount of water is equal to the sum of the formulation agent + polyol + cleaning component + cleaning aid component + other components (to prepare a 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 the tabletting of the 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 the washing sheet, tabletting was possible.

[0055] <Evaluation of the 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 the 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 using a formulated solution 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%) (equipment used: 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 contacted during the storage process, CO3 2- is consumed, so the corresponding 1410 and 1450 cm 2- are affected. -1It is thought that the intensity has decreased. The presence of sorbitol could slow down the decrease of Na2CO3, an alkali builder.

[0057] These results indicate that it has a superior effect in improving cleaning power.

[0058] <Soluble sheet with improved performance using polyol (sorbitol)> We manufactured and evaluated laundry sheets having the following composition.

[0059] [Table 1]

[0060] As shown in Table 2 below, experiments were conducted with a variety of polyols.

[0061] [Table 2]

[0062] Sheets prepared using sorbitol, erythritol, and xylitol as polyols were all easily formulated into dosage forms and were confirmed to exhibit effects similar to those of sorbitol. When using polyols, it was easy to manufacture the sheets even when the content of the formulation agent in the sheet was reduced to a maximum of 23% of the total weight of the sheet. Sorbitol content is less than 20% by weight, and tensile strength is 0.79-3.87 kgf / cm 2 When this is the case, it is confirmed that the sheet has excellent mass production capacity and that the solubility is improved when the sorbitol content is 10% to 20% by weight of the total sheet.

[0063] [Evaluation Result 3] Change in cleaning power according to the sheet storage period (with sorbitol applied vs. without sorbitol applied) (Storage conditions: 20℃, humidity 30%) The cleaning power of the sheets produced in Comparative Example 1 and Example 3 was compared immediately after production and after storage for 4 weeks, and the results are shown in Figure 4. The cleaning power was evaluated using the following method. 1. Terg-o-tometer, 1 liter of water, water temperature 20°C, hardness 50 ppm 2. Contaminated cloth to be used: Japanese wet-type contaminated cloth (116, 2 pieces / L), 3. Sample amount used: Standard usage amount 0.09 g / L 4. Place the specified amount of contaminated cloth and sample into 1 liter of water, then stir and evaluate for 10 minutes. (Evaluate each contaminated cloth separately.) 5. After measuring the Wb value of each soiled cloth using a colorimeter, the cleaning power was calculated using the Harris formula. 6. Check the change by converting the cleaning power immediately after manufacturing to 100. *Storage samples should be kept in a PET16 + LLDPE55 package for 4 weeks.

[0064]

number

[0065] Here, R S is the surface reflectance of the soiled cloth before washing, and R b This is the surface reflectance after washing, and R D This is the surface reflectance of the white cloth. Referring to Figure 4, the sheet containing 15% by weight of sorbitol in Example 3 maintained its initial cleaning power even after 4 weeks of storage, while the sheet without sorbitol showed a decrease in cleaning power of approximately 40%. When sorbitol is applied, it is thought that the reduction in cleaning power due to the decomposition of soda ash (sodium carbonate) is prevented by enhancing storage stability, and that there is no difference in cleaning power between immediately after manufacture and after storage at room temperature. However, the present invention is not to be interpreted in a manner limited by such a theory.

[0066] <Method for evaluating the dissolution rate of soluble sheets> [Evaluation Method] The samples prepared in the examples and comparative examples were measured in 6 × 6 × 0.12 cm. 3 The following was done: In a constant temperature and humidity chamber with a temperature of 20°C and humidity of 30%, 25°C water was prepared, and then a 25cm x 30cm square water tank was filled with the water to a level of 5cm. The sample was floated on the surface of water and the process was repeated five times without stirring until it dissolved, and the average time was measured. Dissolution time was rated as follows: very good if it was within 30 seconds, good if it was between 30 seconds and 3 minutes, average if it was between 3 and 5 minutes, poor if it was between 5 and 10 minutes, and very poor if it was more than 10 minutes. *Criteria for determining dissolution: Dissolution was determined when, after filtering with a 75μm filter, the weight of residual detergent that was not filtered was less than 5% of the total detergent weight.

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

[0068] <Methods and standards for evaluating the mass productivity of laundry sheets> [Methods for evaluating mass productivity] 1. At the factory, after the product had dried, we checked for any breakage when peeling it off the release paper. 2. When 800 kg of the mixture was dried, it was evaluated as good if it was wound onto the rewinder without breaking, poor if it broke during rewinding, and very poor if it broke before rewinding.

[0069] [Method for evaluating tensile strength] 1) A sample measuring 20mm wide, 60mm long, and 1.2mm thick was prepared. 2) Tensile strength was measured using a 500N Zwicki tester manufactured by ZwickRoell in a constant temperature and humidity chamber at 20°C and 30% humidity. 3) After fixing the sample with a distance of 25 mm between the grips, the sample was moved at a speed of 500 mm / min until it broke, and the tensile strength was measured.

[0070] [Experimental Results] [Table 3]

[0071] 1. After 3 measurements, record the average value. 2. The tensile strength tends to decrease as the sorbitol content increases, and the tensile strength tends to decrease sharply from a sorbitol content of 20% onwards. With a sorbitol content of 3.20% or less, mass production was easy without breakage during rewinding. When the sorbitol content exceeded 20%, the sheets broke during the peeling process before the rewinding stage, making production impossible.

[0072] <Evaluation of increased active ingredients and cleaning power of soluble sheets> We investigated whether dosage form is possible even with the use of a small amount of dosage formening agent when using sorbitol, and whether storage stability and solubility are improved. Therefore, we confirmed the change in the ratio of active ingredients, the possibility of increasing the volume, and the resulting change in cleaning power using sorbitol.

[0073] [Table 4]

[0074] [Checking changes in cleaning power] 1. Terg-o-tometer, 1 liter of water, water temperature 20°C, hardness 50 ppm 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 usage amount 0.09 g / L 4. Place the specified amount of contaminated cloth and sample into 1 liter of water, then stir and evaluate for 10 minutes. (Evaluate each contaminated cloth separately.) 5. After measuring the Wb value of each soiled cloth using a colorimeter, the cleaning power was calculated using the Harris formula.

[0075]

number

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

[0077] When the active ingredient level was increased, the cleaning power increased by more than 10% compared to conventional products for all types of contamination, and in particular, the cleaning power increased by approximately 30% for protein contamination (116 / 117). The results are shown in Figure 6.

[0078] <Evaluation of solubility 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 was significantly improved.

[0080] 2. Manufacturing of soluble sheets containing metal ion chlorides <Manufacturing of soluble sheets containing sodium chloride (salt)> The preparation of the compound solution involves adding a water-soluble film-forming polymer (formulator) → polyol → cleaning component → cleaning aid component → other components to 60°C water in that order, stirring at 180 RPM until each component is completely dissolved. At this time, the amount of water is equal to the sum of the formulation agent + polyol + cleaning component + cleaning aid component + other components (to prepare a 50% aqueous solution). In the formulation process, the mixture was formed into a sheet measuring 15 x 25 cm and 1.5 mm thick using a doctor blade, and then dried in a drying oven at 125°C for 12 minutes.

[0081] <Evaluation of formulation for water-soluble laundry sheets> The evaluation will be conducted using the following method. Observe whether the phenomena shown in Figures 1 and 2 occur after drying. Specifically, observe whether the material adheres to the release paper and cannot be peeled off after drying, and then observe whether the sheet does not tear when peeled off the release paper after drying. The evaluation was carried out in a thermo-hygrostat 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 Fig. 1 and Fig. 2 were observed, it was evaluated as very bad.

[0082] In the water-soluble laundry sheet to which metal ion chloride was added, there were few problems such as sticking to the release paper and breakage of the sheet. That is, it was confirmed that it had a positive effect on the tablet forming of the sheet.

[0083]

Table 6

[0084] <Evaluation of stability over time through IR> The water-soluble laundry sheet manufactured using PVA has a problem that as time passes, the decomposition of the washing components and washing aid components is promoted by the decomposition of PVA. Therefore, it was confirmed whether the storage stability was improved by further containing salt. The results are shown in Fig. 7. The IR spectrum was confirmed for the formulation liquid for the laundry sheet manufactured with a 50% aqueous solution and having the following composition. IR was measured immediately after manufacture, 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% thermo-hygrostat chamber)

[0085] From the results in Fig. 7, it was confirmed that when salt was contained, the IR peak of the washing active ingredient changed. In particular, as shown in Fig. 8a and Fig. 8b, when salt was contained at 5% by weight based on 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 understood that salt affects the stability of the active ingredient and improves the detergency 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 3The following was done: In a constant temperature and humidity chamber with a temperature of 20°C and humidity of 70%, 25°C water was prepared, and then a 25cm x 30cm square water tank was filled with the water to a water level of 5cm. The sample was floated on the surface of water and the process was repeated five times without stirring until it dissolved, and the average time was measured. Dissolution time was rated as follows: very good if it was within 30 seconds, good if it was between 30 seconds and 3 minutes, average if it was between 3 and 5 minutes, poor if it was between 5 and 10 minutes, and very poor if it was more than 10 minutes. *Criteria for determining dissolution: Dissolution was determined when, after filtering with a 75μm filter, the weight of residual detergent that was not filtered was less than 5% of the total detergent weight.

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

[0088] <Improvement effect on dissolution rate depending on 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 conducted. The content is expressed in weight percent.

[0089] [Table 7]

[0090] Water-soluble laundry sheets having the compositions shown in Table 7 were prepared, and their dissolution rates were evaluated using the <Method for Evaluating the Dissolution Rate of Soluble Sheets> described above. When the water-soluble laundry sheet containing sulfur oxides (Comparative Example 12) was measured using the above method, the sheet hardly dissolved even after 50 seconds. However, it was confirmed that the water-soluble laundry sheets of Examples 15-17, which contained chlorides, dissolved in the laundry water at a remarkably fast rate. [Industrial applicability]

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

Claims

1. A water-soluble laundry sheet containing a laundry cleaning component, a water-soluble film-forming polymer, and an alkali builder, The water-soluble film-forming polymer is polyvinyl alcohol. The aforementioned water-soluble laundry sheet contains a polyol selected from the group consisting of erythritol, xylitol, mannitol, arabitol, and sorbitol. The water-soluble laundry sheet contains the water-soluble film-forming polymer and the polyol in a ratio of 1.1:1 to 8:

1. A water-soluble laundry sheet in which the aforementioned water-soluble film-forming polymer is used in an amount of 19 to 38% by weight relative to the total weight of the water-soluble laundry sheet after drying.

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

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

4. The water-soluble laundry sheet according to claim 1, wherein the water-soluble film-forming polymer further comprises a polyvinyl alcohol-based copolymer.

5. The water-soluble laundry sheet according to claim 1 or 4, wherein the polyvinyl alcohol or polyvinyl alcohol copolymer has a number average molecular weight of 10,000 to 100,000 and a degree of saponification of 65 to 95%.

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

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

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

9. The water-soluble laundry sheet according to claim 1, further comprising one or more chlorides selected from the group consisting of sodium chloride, magnesium chloride, calcium chloride, and potassium chloride.

10. The water-soluble laundry sheet according to claim 9, wherein the chloride is sodium chloride.

11. The water-soluble laundry sheet according to claim 9, wherein the chloride is contained in an amount of 3 to 7% by weight relative to the total weight of the water-soluble laundry sheet after drying.

12. The aforementioned water-soluble laundry sheet measured at 25°C using a ZwickRoell 500N Zwicki measuring instrument yielded a reading of 0.79 to 3.8 kgf / cm². ２ A water-soluble laundry sheet according to claim 1, having the tensile strength of [value].

13. The water-soluble laundry sheet according to claim 1, wherein the polyol contains sorbitol.

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