JP2010507507A - Water-soluble substrate that has dissolution resistance before being immersed in water - Google Patents

Abstract

  Disclosed are water-soluble substrates, more specifically water-soluble substrates that improve dissolution resistance at neutral pH, and methods for producing the same. Articles such as pouches made from water-soluble substrates are also disclosed herein.

Description

  The present invention relates to a water-soluble substrate, more specifically, a water-soluble substrate having improved dissolution resistance at a neutral pH, and a method for producing the same. The invention also relates to articles such as pouches made from water soluble substrates.

  Water-soluble substrates have gained wide support for use as packaging materials. Examples of packaging materials include films, sheets, blown or molded hollow bodies (ie, sachets, pouches, and tablets), bottles, containers, and the like. Often, water-soluble substrates, when used in the preparation of certain types of these articles, such as sachets and pouches, disintegrate and / or become sticky by exposure to small amounts of water or high humidity. This can be unsuitable for use in packaging and storing the composition contained therein.

  The consumer's most common complaint about water-soluble pouches is that when a water-soluble pouch is accidentally exposed to a small amount of water, for example, after a pouch is sold and purchased, wet hands during storage, high humidity, If water enters the outer packaging from a sink or pipe that leaks, it can lead to undesirable dissolution of the pouch. Thereby, water-soluble pouches may leak and / or stick to each other before use. The second common complaint is that the water-soluble pouch does not completely dissolve during use. Thus, water-soluble substrates and articles made from those substrates, such as sachets and pouches, have improved dissolution resistance to small amounts of water exposure and nevertheless subsequent rinse water There is still an unmet need for articles that can dissolve very quickly when immersed in an aqueous solution, such as wash water.

  Various methods for delaying dissolution of a water soluble substrate are known in the art and typically include coating the water soluble substrate with a material that is water insoluble. For example, US Pat. No. 6,509,072 describes a water soluble substrate that includes a barrier coating. A barrier coating is a polymer film that forms a continuous film on a water-soluble substrate. Another example of the barrier coating is described in PCT International Publication No. 01/23460 (assigned to Kao Corporation), and the surface of the water-soluble substrate is a particulate or fibrous water-insoluble material. The amount of the water-insoluble material coated and used is 0.1 to 80 parts by weight for every 100 parts by weight of the water-soluble film. However, when used (typically including immersing a water-soluble substrate in an aqueous solution), it is desirable for the coating to degrade rapidly. Due to the use of a water-soluble substrate, the aqueous solution in which the substrate or the article comprising the substrate is immersed may have a pH that is acidic or alkaline. Prior art coatings may provide sufficient resistance against accidental water contact (at neutral pH), but when immersed in acidic or alkaline solutions, they may not be able to rapidly degrade or dissolve There is sex.

US Pat. No. 6,509,072 PCT International Patent No. 01/23460

  Accordingly, it is an object of the present invention to provide a water-soluble substrate that can dissolve very rapidly when immersed in an aqueous solution having an acidic or alkaline pH while improving dissolution resistance at neutral pH. It is one aspect.

  The present invention includes a water-soluble substrate having a first surface and a second surface opposite the first surface, the coating having a coating applied to at least one of the first and second surfaces In particular, the coating comprises a material that is water soluble at a pH of 6-7 and further comprises a material that is water soluble at either a pH below 6 or a pH greater than 7.

  The present invention also relates to an article comprising a water-soluble substrate and a method for producing the water-soluble substrate.

Cross section of an uncoated water-soluble substrate. 1 is a cross section of one embodiment of a water soluble substrate according to the present invention. 3 is a cross section of another embodiment of a water-soluble substrate according to the present invention. 3 is a cross section of another embodiment of a water-soluble substrate according to the present invention. 3 is a cross section of another embodiment of a water-soluble substrate according to the present invention. 3 is a cross section of another embodiment of a water-soluble substrate according to the present invention. 3 is a cross section of another embodiment of a water-soluble substrate according to the present invention. Section of an article comprising a water-soluble substrate according to the present invention.

  The present invention relates to a water-soluble substrate, more specifically, a water-soluble substrate having improved dissolution resistance at a neutral pH, and a method for producing the same. However, this water-soluble substrate is water-soluble when immersed in an aqueous solution having an acidic or alkaline pH. The present invention also relates to an article comprising the water-soluble substrate described herein.

Water-Soluble Substrate FIG. 1 shows a cross section of a water-soluble substrate 10. The water-soluble substrate 10 has a first surface 12, a second surface 14 opposite the first surface, and a thickness 16 between the first surface 12 and the second surface 14. The water-soluble substrate 10 can be in the form of a film, sheet, or foam and includes woven and non-woven structures.

  The water-soluble substrate is made of a polymeric material and has a water solubility of at least 50% by weight as measured by the method using a glass filter having a maximum pore size of 20 microns as described later in this specification. Preferably, the substrate has a water solubility of at least 75% by weight, more preferably at least 95% by weight.

  50 grams ± 0.1 grams of substrate material is added to a pre-weighed 400 mL beaker and 245 mL ± 1 mL of distilled water at 25 ° C. is added. This is vigorously stirred for 30 minutes on a magnetic stirrer set at 600 rpm. The mixture is then filtered through a folded qualitative sintered glass filter having a pore size as defined above (up to 20 microns). Water is evaporated from the filtrate collected by any conventional method and the weight of the remaining material is measured (this is the dissolved fraction). The solubility (%) can then be calculated.

  Typically, the water-soluble substrate 10 has a basis weight of 0.33 to 1,667 g / square meter, preferably 33 to 167 g / square meter. The thickness of the water soluble substrate 10 between the first surface 12 and the second surface 14 is from about 0.75 micrometers to about 1,250 micrometers, preferably from about 10 micrometers to about 250 micrometers, and more. Preferably it can range from about 25 micrometers to about 125 micrometers.

  Preferred polymers, copolymers or derivatives thereof suitable for use as a substrate material are polyvinyl alcohol (PVA), polyvinyl pyrrolidone, polyalkylene oxide, acrylamide, acrylic acid, cellulose, cellulose ether, cellulose ester, cellulose amide, polyvinyl Acetates, polycarboxylic acids and salts, polyamino acids or peptides, polyamides, polyacrylamides, maleic / acrylic acid copolymers, polysaccharides including starch and gelatin, natural gums such as xanthum and carragum, poly Acrylate and water-soluble acrylate copolymer, methylcellulose, sodium carboxymethylcellulose, dextrin, ethylcellulose, hydroxyethylcellulose, hydroxypropyl Pills methylcellulose, maltodextrin, polymethacrylates, polyvinyl alcohol copolymers, hydroxypropyl methyl cellulose (HPMC), and mixtures thereof. The most preferred polymer is polyvinyl alcohol. Preferably, the polymer concentration in the substrate is at least 60%.

  An example of a commercially available water-soluble film is a PVA film known as the trade name MonoSol M8630 sold by MonoSol LLC (Gary, Ind.), And the corresponding solubility and deformation. It is a PVA film having characteristics. Other films suitable for use herein include trade name PT films supplied by Aicello or films known as K-series films, or VF- supplied by Kuraray. An HP film is mentioned.

pH Sensitive Coating As shown in FIG. 2, the coating 20 is applied to, preferably substantially covers, at least one of the first surface 12 or the second surface 14 of the water-soluble substrate 10. By “substantially covering” is meant that at least 95%, preferably at least 99%, most preferably 100% of the first surface 12 or the second surface 14 is covered by the coating 20. This is because water cannot reach the first surface 12 or the second surface 14 of the water-soluble substrate 10 when accidentally contacted with water, or the amount of water reaching this surface is water soluble. Assures that the substrate 10 is insufficient to completely dissolve.

  The coating 20 is preferably applied at a weight ratio of the coating to the water-soluble substrate of 0.1 to 100, preferably 0.1 to 10, and more preferably 0.2 to 2.

  The coating 20 comprises a material that is water insoluble at a pH of 6-7 and is water soluble at either a pH below 6 or a pH greater than 7 (also referred to as a “pH sensitive material”). Water that can accidentally come into contact with a water-soluble substrate, such as water from a leaking pipe or from contact with wet hands, has a neutral pH. Thus, the coating of the present invention protects water soluble substrates. Articles made of water-soluble substrates include, for example, pouches filled with detergents. The aqueous environment in which these pouches are used often has an acidic or alkaline pH. Thus, the coating of the present invention dissolves quickly in these environments, ensuring that the water soluble substrate dissolves rapidly.

  The term “water soluble at a pH of 6-7” means that the material has a water solubility of at least 50% by weight at a pH of 6-7. Preferably, the water solubility is at least 75% by weight, more preferably at least 95% by weight as measured by the method previously described herein.

  The term “water-insoluble at a pH below 6” or “water-insoluble at a pH above 7” means that the material has a water solubility of less than 50% by weight at a pH below 6 or at a pH above 7. It means having. The water solubility is preferably less than 40% by weight, more preferably less than 30% by weight. In order to measure the water solubility at a specific pH, the pH of distilled water used in the method described earlier in this specification is appropriately adjusted.

  Such a coating 20 is not able to reach the surface of the water-soluble substrate 10 because the coating 20 has sufficient resistance in the case of accidental contact with water such as contact with wet hands. Provides the advantage. Depending on the environment (acidic or alkaline) in which the water-soluble substrate 10 is used, the coating can rapidly dissolve or decompose, and therefore excess water can be brought to the water-soluble substrate 10.

  In one embodiment, the coating 20 is at a pH of less than 6, preferably at a pH of 1 to 5.9, more preferably at a pH of 1.5 to 5.5, and even more preferably at a pH of 2 to 5. Includes materials that are water soluble. Examples of suitable materials that are soluble in an acidic environment include vinylpyrridrine / styrene copolymer materials (Adisseo) that are soluble at a pH of 2.0 but insoluble at pH greater than 2.0. (Supplied by Alpharetta, Georgia), SQZgel pH-sensitive polymer mixture (MacroMed Inc., supplied by Sandy, Utah) that is soluble at pH greater than 3.0 ), Meta-acrylic acid and copolymer materials that are soluble at a pH greater than 4.5 (supplied by Bristol Myers Squibb (New York, NY)) at a pH greater than 5.5 Eudragit L30D (Rohm Pharma) which is soluble Degussa (Rhom Pharma / Degussa) supplied by (NJ Rockaway (Rockaway))) include, but are not limited to.

  In another embodiment, the coating 20 is at a pH greater than 7, preferably at a pH of 7.5-15, more preferably at a pH of 8-14.5, and even more preferably at a pH of 8.5-14. Includes materials that are water soluble. Examples of suitable materials that are soluble in an alkaline environment include Eudragit S100 (Rhom Pharma / Degussa, Rockaway, NJ), which is soluble at a pH greater than 7.0. )), And styrene (or acrylic acid) / p-hydroxystyrene copolymer materials (supplied by Sandoz (Princeton, NJ)) that are soluble at a pH greater than 8.0. It is not limited to.

  The coating 20 comprises at least 50 wt%, preferably at least 60 wt%, more preferably at least 70 wt%, even more preferably at least 80 wt%, and even more preferably at least 90 wt% pH sensitive material. preferable. Most preferably, the coating 20 consists essentially of a pH sensitive material.

In certain applications, the dissolution rate of the coating 20 itself (when immersed) can be applied by applying it to a separable area of acidic material (for acidic pH sensitive coatings) or (for alkaline pH sensitive coatings). It increases by applying to the separable region of the alkaline material. As used herein, "discrete region" refers to a preferably 0.1mm ² ~400mm ^2, more preferably 1 mm ² to 200 mm ^2, further relatively small exposed surface area of preferably 10 mm ² 100 mm ² Means areas that may have patterns that do not touch each other and can be random or non-random. These separable regions, when combined in surface area, are from 10%, preferably from 20%, more preferably from 30%, even more preferably from 40% of the surface area of the first surface 12 or the second surface 14. It corresponds to up to 70%, preferably up to 80%, more preferably up to 90%. When soaked, these separable regions of the acidic or alkaline material ensure that the pH is locally reduced or increased and thus have a promoting effect on the degradation of the coating 20. Acidic or alkaline materials can be applied in various ways.

  In one embodiment, an acidic or alkaline material is applied in the coating 20, as shown in FIG. 3A. More specifically, the pH sensitive coating 20 is first applied in a discontinuous manner, and then the acidic / alkaline material is applied to the region 25 not covered by the pH sensitive coating. Alternatively, the acidic / alkaline material is first applied to the separable region and then the pH sensitive coating 20 is applied. In order to avoid the possibility of actually inducing degradation of the pH sensitive coating 20 by accidental contact with water, the coating 26 of a material having a lower water solubility than the water soluble substrate 10 is an acidic / alkaline material. It is preferable to apply to the separable region 25.

  In another embodiment, as shown in FIG. 3B, an acidic or alkaline material is applied over the pH sensitive coating. In order to avoid the possibility of actually inducing degradation of the pH sensitive coating 20 by accidental contact with water, the coating 26 of a material having a lower water solubility than the water soluble substrate 10 is an acidic / alkaline material. Is preferably applied to the separable region 25 and optionally to the top of the pH-induced coating 20.

  In another embodiment, as shown in FIG. 3C, an acidic or alkaline material is applied between the surface of the water soluble substrate and the pH sensitive coating 20.

  In yet another embodiment, an acidic or alkaline material is incorporated into the water-soluble substrate 10, as shown in FIG. 3D.

  In yet another embodiment, as shown in FIG. 3E, an acidic or alkaline material is applied to the surface of the water soluble substrate opposite the surface to which the pH sensitive coating 20 is applied.

  The separable region 25 of the acidic or alkaline material preferably corresponds to less than 20% by weight of the water-soluble substrate 10. Examples of acidic materials include salts formed with strong acids and weak bases (such as ammonium chloride), salts formed with weak acids and weak bases having acidic pKa (hydrolysis), organic acids and inorganic acids, salts thereof , Acid precursors, or combinations thereof, but are not limited to these. Organic acid compounds include carboxylic acid, phenolic acid, ascorbic acid (vitamin C for food use), humic acid, wood vinegar, acetic acid, benzoic acid, butyric acid, citric acid, formic acid, lactic acid, malic acid, mandelic acid, methanethiol , Propionic acid, pyruvic acid, valeric acid. Examples of inorganic acid compounds include hydrobromic acid, hydrochloric acid, hydroiodic acid, nitric acid, sulfuric acid, perchloric acid, boric acid, carbonic acid, chloric acid, hydrofluoric acid, phosphoric acid, and pyrophosphoric acid.

  Preferred alkaline materials include salts formed with weak acids and strong bases (such as sodium acetate) and salts formed with weak acids and bases with basic pKa (hydrolysis), carbonates and bicarbonates, metal hydroxides Products, ammonia and amines, monoethanolamine, metal oxides, pyridine, salts thereof, and combinations thereof, but are not limited thereto.

  The coating 20 may further include other water-soluble components that are resistant to accidental water contact and that are lower than the water-soluble substrate 10.

  One example of such a component is polyvinyl alcohol with a high degree of hydrolysis. Preferably, the degree of hydrolysis of the polyvinyl alcohol used for the coating is greater than 97%.

  Another example of such a component is an inorganic or organic material. Inorganic materials include zeolite, bentonite, talc, mica, kaolin, leptite, silica, calcium carbonate, titanium oxide, anhydrous silicic acid, calcium hydroxyapatite, phthalocyanine blue, herringdon pink, hanza orange, pearl luster, etc. Zeolite, bentonite, talc, mica, kaolin, silica, titanium oxide, silicone and the like are preferable. The organic material is polyethylene, polypropylene, polyamide, polyethylene terephthalate, polystyrene, polyurethane and / or a crosslinked product thereof, sodium poly (meth) acrylate, poly (meth) acrylate ester and / or a crosslinked product thereof, ethylene rubber, propylene rubber Synthetic polymers selected from rubbers such as styrene-butadiene rubber, butadiene rubber, silicone rubber and / or cross-linked products thereof, or cellulose and / or derivatives thereof, starch and / or derivatives thereof, seed hulls and / or It may be a natural polymer such as a derivative. Polyethylene, polyamide, polystyrene, sodium poly (meth) acrylate, poly (meth) acrylate, cellulose and / or a derivative thereof, starch, and the like are preferable. However, poly (meth) acrylic acid means both polyacrylic acid and polymethacrylic acid.

  The coating according to the invention can be opaque but is preferably transparent or translucent. Colored or three-dimensional coatings are also preferred to create prominent effects such as tactile (contact) effects or visual effects (eg graphics, cartoons, logos, brands, user instructions, etc.).

Optional components For certain applications, it may be necessary to increase the dissolution rate (when immersed) of the water-soluble substrate 10. A disintegrant may be added to the coating 20 to accelerate dissolution when the water-soluble substrate is immersed in water. When present, the concentration of disintegrant in the coating 20 is 0.1 to 30% by weight of the coating 20, preferably 1 to 15%. Alternatively, the disintegrant may also be applied to the surface of the water-soluble substrate 10, opposite to the surface to which the coating 20 is applied, or applied to both surfaces of the water-soluble substrate 10. Or may be incorporated in the water-soluble film 10 or any combination thereof. Any suitable disintegrant can be used. Preferred disintegrants for use herein include corn / potato starch, methylcellulose / cellulose, mineral clay powder, croscarmellose (crosslinked cellulose), crospovidine (crosslinked polymer), sodium glycolate starch (crosslinked starch) ).

  For example, a dye index such as litmus may be optionally applied to the water-soluble substrate 10 in or on the pH sensitive coating 20 or a combination thereof. Such an indicator can visually indicate that the pH sensitive coating is activated, thereby providing the consumer with a signal that the system is functioning.

  The water-soluble substrate-forming composition and the water-soluble substrate 10 formed therefrom can also include one or more additives or adjuvant components. For example, the water-soluble substrate forming composition and the water-soluble substrate 10 can be used as a plasticizer, a lubricant, a mold release agent, a filler, an extender, an antiblocking agent, an adhesive remover, an antifoaming agent, or other functions. Ingredients may be included. For articles containing a cleaning composition, the latter includes, but is not limited to, functional detergent additives delivered to the cleaning water, such as organic polymer dispersants, or other detergent additives.

  Suitable plasticizers include glycerol, glycerin, diglycerin, hydroxypropyl glycerin, sorbitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, neopentyl glycol, trimethylol propane, polyether polyol , Ethanolamine, and mixtures thereof, but are not limited to these. The plasticizer is in a suitable amount (but not limited to) in an amount ranging from about 5% to about 30% by weight, or in the range from about 12% to about 20% by weight. 10 can be incorporated.

  Suitable surfactants can include nonionic, cationic, anionic, and bipolar classes. Suitable surfactants include polyoxyethylenated polyoxypropylene glycol, alcohol ethoxylate, alkylphenol ethoxylate, tertiary acetylene glycol and alkanolamide (nonionic substance), polyoxyethylenated amine, quaternary ammonium Examples include, but are not limited to, salts and quaternized polyoxyethylenated amines (cationic materials) and amine oxides, N-alkylbetaines and sulfobetaines (dipolar materials). The water-soluble substrate in any suitable amount, including the surfactant in an amount ranging from about 0.01 wt% to about 1 wt%, or from about 0.1 wt% to about 0.6 wt%. 10 can be incorporated.

  Suitable lubricants / release agents include, but are not limited to, fatty acids and their salts, fatty alcohols, fatty acid esters, aliphatic amines, aliphatic amine acetates, and fatty acid amides. Any suitable amount of lubricant / release agent, including an amount in the range of about 0.02 wt% to about 1.5 wt%, or in the range of about 0.04 wt% to about 0.15 wt% Can be incorporated into the water-soluble substrate 10.

  Suitable fillers, extenders, antiblocking agents, detackifiers include starch, modified starch, crosslinked polyvinylpyrrolidone, crosslinked cellulose, microcrystalline cellulose, silica, metal oxide, calcium carbonate, talc and mica. However, it is not limited to these. Fillers, extenders, antifoaming agents, and tack removers are in the water-soluble substrate 10 in the range of about 0.1 wt% to about 25 wt%, preferably about 1 wt% to about 15 wt%. Can be present in any suitable amount, such as a range of amounts. In the absence of starch, it may be desirable for fillers, extenders, antiblocking agents, and detackifiers to be present in the range of about 1% to about 5% by weight.

  Suitable antifoaming agents include, but are not limited to, those based on blends of polydimethylsiloxane and hydrocarbons. The antifoaming agent is contained in the water-soluble substrate 10 in an amount ranging from about 0.001% to about 0.5% by weight, preferably from about 0.01% to about 0.1% by weight. In any suitable amount.

  The water-soluble substrate-forming composition is obtained by mixing the materials and stirring the mixture until the solution is complete while raising the temperature from about 21 ° C. (about 70 ° F.) to about 90 ° C. (195 ° F.). Prepared. The substrate-forming composition may be in any suitable form (eg, film or sheet) and then form any suitable product (eg, single and multi-compartment pouches, sachets, bags, etc.). .

Methods for Producing Water-Soluble Substrate There are numerous non-limiting embodiments of the method for producing water-soluble substrate 10 described herein.

  In one embodiment, the method includes providing a previously formed water soluble substrate 10 and applying a coating 20 to at least one of the surfaces 12, 14 of the previously formed water soluble substrate 10. The process of carrying out.

  The coating 20 can be applied to the previously formed water-soluble substrate 10 in a number of different ways. In one non-limiting embodiment, the coating 20 is applied in the form of particles or powder to at least one of the surfaces 12, 14 of the previously formed water-soluble substrate 10. Preferably, the particles or powder are applied to the water-soluble substrate 10 via a jet or electrostatically. Due to the high speed of the jet, some particles / powder are embedded in the substrate, thereby reducing or even eliminating the need to use a binder. Similarly, binders are generally not required when particles or powders are applied electrostatically. Nevertheless, binders may be used. A binder may be first applied to the water-soluble substrate 10 before applying the particles or powder. Alternatively, the binder may be mixed with the particles or powder, and then the mixture is added to the water-soluble substrate 10.

  In another non-limiting embodiment of the present invention, the coating 20 is provided in the form of a solution that is applied to at least one of the surfaces 12, 14 of the water-soluble substrate 10, and is dried or subjected to a drying process. Applied. The solution can be applied onto the film by any coating method such as spraying, knife, rod, kiss, slot, painting, printing and mixing thereof. Printing is preferred for use herein. Printing is a well established economic process. Printing is usually done with ink and dye and is used to impart a pattern and color to the substrate, but in the case of the present invention, the printing deposits less water soluble material on the water soluble substrate. Used for. Any kind of printing method can be used, including rotogravure, lithographic printing, flexographic printing, porous and screen printing, ink jet printing, letterpress printing, tamography, and combinations thereof.

  These embodiments may also include wetting at least a portion of at least one of the surfaces 12, 14 of the water-soluble substrate 10 before applying the coating 20 to the previously formed water-soluble substrate 10. Good. Wetting at least one of the surfaces 12, 14 of the water-soluble substrate 10 is used to at least partially dissolve the exterior of the surfaces 12, 14 of the substrate 10 (ie, halfway through the thickness of the substrate). Or it may be solubilized. In order to partially embed the coating in the substrate, the water-soluble substrate 10 may be at least partially solubilized to any suitable depth. Suitable depths include about 1% to about 40% or about 45%, about 1% to about 30%, about 1% to about 20%, about 1% to about 15% of the total thickness 16 of the substrate. Or about 1% to about 10%, but is not limited thereto. A less water soluble material 20 is then applied to at least one partially dissolved location of the surfaces 12, 14 of the substrate 10. This allows the coating 20 to be embedded in the outer portions of the surfaces 12, 14 of the substrate 10 and become a more permanent part of the substrate 10. Next, the wetted surfaces 12, 14 of the substrate 10 embedded with the coating 20 are dried. Such an embodiment of the present method may also include free portions of the coating 20 remaining on the surface after the water-soluble substrate 10 has dried, such as by wiping or dusting the surface of the substrate 10. You may include the process of removing at least one part of excess.

  In another embodiment, the coating 20 can be added to the water-soluble substrate 10 after the substrate 10 has been manufactured into a product. For example, if the water soluble substrate 10 is used to form a water soluble pouch containing the composition, the coating 20 can be added to the substrate 10 over at least a portion of the surface of the water soluble pouch. .

  In another non-limiting embodiment of the method, the coating 20 is applied in multiple application steps. The first layer of coating 20 is applied to water-soluble substrate 10 according to any of the methods described above and is optionally dried. Subsequently, one or more additional coating layers may be added (each optionally including a drying step) until the desired coating thickness is obtained. In this way, a relatively thick coating can be made on a thin water-soluble substrate.

  In another non-limiting embodiment of the method, the coating layer may be formed separately and then applied as a coating layer to the surface of the water-soluble substrate.

Method for Producing Water-Soluble Pouch From the water-soluble substrate 10 described in the present specification, articles in which the water-soluble substrate 10 is used as a packaging material can be formed, but articles not limited thereto can be formed. Such articles include, but are not limited to, water-soluble pouches, sachets, and other containers.

  Water-soluble pouches and other such containers that incorporate the water-soluble substrate 10 described herein can be manufactured in any suitable manner known in the art. The water-soluble substrate 10 can have improved dissolution resistance either before or after it is formed into a final product. In any case, in certain embodiments, when manufacturing such an article, it is desirable that the surfaces 12, 14 of the substrate 10 to which the coating is applied form the outer surface of the article.

  There are a number of processes for producing water-soluble pouches. These include, but are not limited to, processes known in the art as vertical fill seal processes, horizontal fill seal processes, and pouch formation in a mold on a circular drum surface. In the vertical fill seal process, the vertical tube is formed by folding the substrate. The bottom end of the tube is sealed to form an open pouch. This pouch is partially filled in consideration of the head space. Next, the uppermost part of the open-type pouch is sealed together to close the pouch, and the next open-type pouch is formed. The first pouch is then cut and the process is repeated. Pouches formed by such methods usually have a pillow shape. The horizontal mold fill seal process uses a die having a series of molds therein. In a horizontal form-fill-seal process, the substrate can be placed in dies, open pouches formed in these molds, which are then filled, covered with another layer of substrate, and sealed. it can. In the third process (formation of the pouch in the mold on the surface of the circular drum), the substrate circulates over the drum to form a pocket, which passes under the filling machine and fills the open mold pocket. . Filling and sealing takes place at the highest point (top) of the circle drawn by the drum, for example typically filling just before the rotating drum starts a downward circular motion and sealing the drum downwards Perform immediately after exercising.

  In any of the processes involving the step of forming an open pouch, the substrate can first be formed or formed into the shape of an open pouch using thermoforming, vacuum forming, or both. Thermoforming can be accomplished by applying heat in any known manner, such as contacting the mold with a heating element, or blowing hot air, or heating the mold and / or substrate using a heating lamp. And / or with heating the substrate. In the case of vacuum formation, vacuum assistance is used to help place the substrate into the mold. In other embodiments, the two techniques can be combined to form a pouch, for example, the substrate can be formed into an open pouch by vacuum forming and providing heat to facilitate the process. it can. The open pouch is then filled with the composition contained therein.

  The filled open pouch is then closed, which can be done in any manner. In some cases, such as a horizontal pouch forming process, a second material or substrate, such as a water soluble substrate, is continuously fed over and over the web of the open pouch, and then the first substrate and the second substrate. Closing is done by sealing the substrates together. The second material or substrate can include the water-soluble substrate 10 described herein. It may be desirable for the surface of the second substrate on which the coating is applied to be oriented to form the outer surface of the pouch.

  In such a process, the first and second substrates are typically sealed in the region between the molds, and thus between the pouches formed in the adjacent molds. Sealing can be performed by any method. Sealing methods include heat sealing, solvent adhesion, and solvent or wet sealing. The sealed pouch web can then be cut by a cutting device, which cuts the pouches in the web from one another into separate pouches. Processes for forming water-soluble pouches are further described in US patent application Ser. No. 09 / 994,533, US Patent Application Publication No. 2002/0169092 A1 (published by the name of Catlin et al.).

Articles of Manufacture As shown in FIG. 4, the present invention includes a product composition 40 and a water soluble group that may be formed in a container 30 such as a pouch, sachet, capsule, bag, etc. for holding the product composition. Articles including the material 10 are also included. The surface of the water-soluble substrate 10 to which the coating 20 is applied may be used to form the outer surface of the container 30. The water-soluble substrate 10 can form at least a portion of the container 30 that provides a unit dose of the product composition 40.

  For simplicity, the articles of interest herein are described in terms of water-soluble pouches, but it should be understood that the discussion herein also applies to other types of containers.

  The pouch 30 formed by the method described above is contained in the composition 40 contained therein until it is desired to release the composition 40 from the water-soluble pouch 30, such as by immersing the water-soluble pouch 30 in water. Can be of any form and shape suitable for holding. The pouch 30 can include one compartment or two or more compartments (ie, the pouch can be a multi-compartment pouch). In one embodiment, the water-soluble pouch 30 may have two or more compartments in a generally overlapping relationship, with the pouch 30 defining the upper and lower outer walls, the sides of the pouch 30. It includes a skirt-like side wall to form, as well as one or more internal partitions that separate different compartments from one another. If the composition 40 contained within the pouch 30 includes different forms or components, the different components of the composition 40 can be contained in different compartments of the water-soluble pouch 30 and are separated from each other by a barrier of water-soluble material. Can be separated.

  Pouches or other containers 30 are in contact with laundry detergent compositions, automatic dishwashing detergent compositions, hard surface cleaners, stain removers, fabric strengtheners and / or softeners, food and beverages, and small amounts of water. One or more compositions for use in or in new product forms that may cause premature pouch dissolution, undesirable pouch leakage, and / or undesirable pouch adhesion A unit dose of product 40 may be included. The composition 40 in the pouch 30 can be in any suitable form including, but not limited to, liquids, liquid gels, gels, pastes, creams, solids, granules, powders, and the like. Different compartments of the multi-compartment pouch 30 can be used to separate incompatible components. For example, it may be desirable to separate the bleach and enzyme into separate compartments. Other forms of multi-compartment embodiments can include powder-containing compartments combined with liquid-containing compartments. Additional examples of multi-compartment water-soluble pouches are disclosed in US Pat. No. 6,670,314 B2 (Smith et al.).

  The water-soluble pouch 30 may be put into any suitable aqueous solution (such as hot water or cold water), and as soon as that the water-soluble substrate material 10 forming the water-soluble pouch 30 is dissolved, the content of the pouch Release things.

  The water-soluble substrate 10 described herein can also be used in coating products and other articles. Non-limiting examples of such products are laundry detergent tablets or automatic dishwashing detergent tablets. Other examples include coating products in the food and beverage category that may result in pouch dissolution, undesirable leakage, and / or undesirable sticking that is prematurely contacted with a small amount of water.

An example using a pH-induced coating that induces dissolution of a water-soluble / dispersible substrate in the presence of tap water at a pH of 7-8 is described below.
A pH-triggered coating such as SQXgel ™ (supplied by MacroMed (Sandy, Utah)) that dissolves at a pH of 3.0 is first applied to the water-soluble substrate. . Next, a small separable area (such as dots) of acidic material (such as citric acid) is applied over the pH-induced coated substrate. Due to the small amount during application of the acidic material and the rapid drying, the pH-induced coating is not substantially solubilized / disintegrated. A third layer of a water resistant coating (eg, talc) is applied over the substrate to cover both the acidic material and the pH induced coating. In the presence of small amounts of water (wet hands, raindrops, accidental contact with spilled water), the coated substrate does not solubilize / disintegrate. When immersed in a full tank of tap water at a pH of 6-7 for the required time (such as when used in consumer applications), the outermost water-resistant coating layer is solubilized. Next, the acidic material in contact with water causes a localized low pH (pH of 2.0-2.5) region to induce dissolution of the rest of the coating or the underlying water soluble substrate. On the substrate.

  The dimensions and values disclosed herein are not to be interpreted as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.

Claims (12)

  A first surface (12) and a second surface (14) opposite the first surface (12), wherein the first surface (12) and the second surface (14) A water-soluble substrate (10) having a coating (20) applied to at least one, wherein the coating (20) comprises (A) an acidic material that is water-soluble at a pH of 6-7. Region (25) and (B) a water-soluble substrate (10), characterized in that it comprises a pH sensitive material that is water soluble at a pH below 6.   A first surface (12) and a second surface (14) opposite the first surface (12), wherein the first surface (12) and the second surface (14) A water-soluble substrate (10) having a coating (20) applied to at least one, wherein the coating (20) comprises (A) an alkaline material that is water-soluble at a pH of 6-7. Region (25) and (B) a water-soluble substrate (10) characterized in that it comprises a pH sensitive material that is water soluble at a pH greater than 7.   The water-soluble substrate (10) according to claim 1, wherein the coating (20) is water-soluble at a pH of 1 to 5.9.   The water soluble substrate (10) of claim 2, wherein the coating (20) is water soluble at a pH of 7.5-15.   The water-soluble substrate (10) according to claim 1, wherein the acidic substrate is selected from the group consisting of organic acids, inorganic acids, acid precursors, acetates or combinations thereof.   The alkaline material is a salt formed with a weak acid and a strong base, a salt formed with a weak base with a weak acid and a basic pKa, carbonate and bicarbonate, metal hydroxide, ammonia and amine, monoethanolamine The water-soluble substrate (10) according to claim 2, wherein the water-soluble substrate (10) is selected from the group consisting of, metal oxides, pyridine, salts thereof and combinations thereof.   The separable region (25) is in the coating (20), on the coating (20), between the coating (20) and the at least one surface (12, 14), and the water-soluble substrate (10). ), The surface of the water-soluble substrate (10) opposite to the surface to which the coating (20) is applied, or a site selected from the group consisting of combinations thereof. A water-soluble substrate (10) as described in 1.   The water-soluble substrate (10) according to claim 1 or 2, wherein the separable region (25) and the pH sensitive material represent less than 20% by weight of the water-soluble substrate (10).   9. The at least one of claims 1 to 8, wherein at least one of the first surface (12) and the second surface (14) to which the coating (20) is applied forms an outer surface. Article (30) comprising a water-soluble substrate (10).   The article (30) of claim 9, wherein the water-soluble substrate (10) forms at least part of a container comprising a product composition.   A method of producing a water-soluble substrate (10) that is resistant to dissolution prior to being immersed in an aqueous environment, the method comprising applying a coating (20) to at least one surface of the water-soluble substrate (10). A separable region (25) wherein the coating (20) comprises an acidic material that is water soluble at a pH of 6-7, and (B) a pH sensitive material that is water soluble at a pH of less than 6. A method characterized by comprising.   A method for producing a water-soluble substrate (10) having dissolution resistance before being immersed in an aqueous environment, the method comprising applying a coating (20) to at least one surface of the water-soluble substrate (10) And wherein the coating (20) comprises a separable region (25) comprising an alkaline material that is water soluble at a pH of 6-7 and (B) a pH sensitive material that is water soluble at a pH greater than 7. And how to.

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