Thickening system and preparation method thereof, oral care composition and pump toothpaste

Abstract

The invention discloses a thickening system and a preparation method thereof, an oral care composition and pump toothpaste. The preparation method of the thickening system comprises the following steps: preparing a first dispersion system: dispersing a first thickening agent and a first solvent to obtain the first dispersion system; wherein the first thickening agent comprises microcrystalline cellulose and carboxymethyl cellulose salt; preparing a second dispersion system: dispersing a second thickening agent and a second solvent to obtain the second dispersion system; wherein the second thickening agent comprises at least one of magnesium lithium silicate and magnesium aluminum silicate; and preparing a thickening system: dispersing the first dispersion system and the second dispersion system at a third temperature at a third speed for third time to obtain the thickening system. The thickening system disclosed by the invention has good shear thinning capacity and relatively rapid upright recovery, and is used for preparing the oral care composition, and the oral care composition also has good rheological property.

Description

Technical Field

[0001] The present application relates to the field of oral care technology, and in particular to a thickening system and a preparation method thereof, an oral care composition, and a pump toothpaste. Background Art

[0002] Oral health is an important component of overall well-being, directly impacting a person's quality of life and social interactions. Oral care products such as toothpaste, mouthwash, and mouth spray are increasingly popular among consumers. Toothpaste is a daily care product used to clean teeth and maintain oral hygiene. It typically comes in a paste form and is used with a toothbrush. Pump toothpaste is a product designed to dispense toothpaste by pressing a pump head. Pump toothpaste is typically packaged in a vertical plastic container with a pump head on top. When the user presses the pump head, the toothpaste is pushed onto the surface for easy access.

[0003] The extrusion of pump-type toothpaste requires higher rheological properties of the toothpaste. If the shear thinning ability of the toothpaste is poor, it may make the toothpaste difficult to pump out. If the uprightness of the toothpaste recovers slowly after being pumped out, it will also affect the user experience.

[0004] Therefore, there is an urgent need to provide a toothpaste with better rheological properties and related products and preparation methods. Summary of the Invention

[0005] The present application provides a thickening system and a preparation method and application thereof, an oral care composition and a preparation method thereof, which are used to solve the problem of poor rheological properties of existing toothpastes.

[0006] The first aspect of the present application discloses a method for preparing a thickening system, comprising: preparing a first dispersed system: dispersing a first thickener and a first solvent at a first temperature and a first speed for a first time to obtain the first dispersed system; wherein the first thickener comprises microcrystalline cellulose and a carboxymethyl cellulose salt; preparing a second dispersed system: dispersing a second thickener and a second solvent at a second temperature and a second speed for a second time to obtain the second dispersed system; wherein the second thickener comprises at least one of lithium magnesium silicate and magnesium aluminum silicate; preparing the thickening system: dispersing the first dispersed system and the second dispersed system at a third temperature and a third speed for a third time to obtain the thickening system.

[0007] In one implementation of the present application, the carboxymethyl cellulose salt includes at least one of the following: sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, ammonium carboxymethyl cellulose, and calcium carboxymethyl cellulose.

[0008] In an implementation form of the application, the first solvent or the second solvent comprises at least one of water, glycerin, propylene glycol, PEG-8, sorbitol.

[0009] In an implementation form of the application, the first temperature is 0-80℃, the first speed is 500-20000 rpm, and the first time is 5-60 minutes.

[0010] In an implementation form of the application, the second temperature is 0-80℃, the second speed is 500-20000 rpm, and the second time is 5-60 minutes.

[0011] In an implementation form of the application, the third temperature is 0-80℃, the third speed is 200-20000 rpm, and the third time is 2-60 minutes.

[0012] In an implementation form of the application, the first dispersion system comprises, in terms of mass parts, 0.3-16 parts of microcrystalline cellulose, 0.1-2 parts of a carboxymethyl cellulose salt, and 2-70 parts of the first solvent.

[0013] In an implementation form of the application, the second dispersion system comprises, in terms of mass parts, 0.3-2 parts of the second thickening agent and 3-70 parts of the second solvent.

[0014] In an implementation form of the application, the thickening system comprises, in terms of mass parts, 0.3-16 parts of microcrystalline cellulose, 0.1-2 parts of a carboxymethyl cellulose salt, 0.3-2 parts of the second thickening agent, and 10-80 parts of a solvent, the solvent comprising the first solvent and the second solvent.

[0015] In an implementation form of the application, the first dispersion system is a gel system, and the second dispersion system is a gel system.

[0016] A second aspect of the application discloses a thickening system, comprising a first dispersion system and a second dispersion system, the first dispersion system comprising microcrystalline cellulose, a carboxymethyl cellulose salt, and a first solvent, and the second dispersion system comprising a second thickening agent and a second solvent, the second thickening agent comprising at least one of lithium magnesium silicate and magnesium aluminum silicate; or, the thickening system is prepared by the above preparation method.

[0017] In an implementation form of the application, the first solvent or the second solvent comprises at least one of water, glycerin, propylene glycol, PEG-8, sorbitol.

[0018] In one implementation of the present application, the thickening system comprises, in parts by mass, 0.3-16 parts of microcrystalline cellulose, 0.1-2 parts of carboxymethyl cellulose salt, 0.3-2 parts of the second thickening agent, 10-80 parts of solvent, the solvent comprising the first solvent and the second solvent.

[0019] The third aspect of the present application discloses an oral care composition comprising the thickening system prepared by the preparation method disclosed in the first aspect of the present application or comprising the thickening system disclosed in the second aspect of the present application.

[0020] In one implementation of the present application, the oral care composition further comprises an abrasive agent and a foaming agent.

[0021] In one implementation of the present application, the abrasive agent comprises at least one of the following: silicon dioxide, hydrated silica, calcium carbonate, calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, calcium pyrophosphate, aluminum hydroxide.

[0022] In one implementation of the present application, the oral care composition comprises, in parts by mass, 50-80 parts of the thickening system, 10-50 parts of the abrasive agent, and 0.5-5 parts of the foaming agent.

[0023] In one implementation of the present application, the oral care composition comprises, in parts by mass, 0.3-16 parts of microcrystalline cellulose, 0.1-2 parts of carboxymethyl cellulose salt, 0.3-2 parts of the second thickening agent, 10-50 parts of the abrasive agent, 0.5-5 parts of the foaming agent, and 10-80 parts of solvent, wherein the solvent comprises the first solvent and the second solvent.

[0024] In one implementation of the present application, the oral care composition has a viscosity of 300,000-1,200,000 cp under a shear condition of 5 rpm and a viscosity of 20,000-300,000 cp under a shear condition of 50 rpm.

[0025] In one implementation of the present application, the oral care composition has a thixotropic loop area of ≥800 Pa·s.

[0026] The fourth aspect of the present application discloses a pump toothpaste comprising a container body and a pump head connected to the container body, the container body being configured to contain the oral care composition disclosed in the third aspect of the present application, and the pump head being configured to pump the oral care composition out of the container body under the action of pressing.

[0027] The present application has the following beneficial effects:

[0028] The thickening system of the present application is prepared by separately preparing a first dispersed system and a second dispersed system, and then mixing the two dispersed systems to obtain the thickening system. Compared to a thickening system obtained by direct one-step mixing, the thickening system of the present application can combine high viscosity, significant shear thinning, and rapid thixotropic recovery, making it particularly suitable for use in pump toothpastes. Specifically, the first dispersed system is prepared using microcrystalline cellulose and carboxymethyl cellulose salt, which can synergistically form a denser and more stable three-dimensional network that encapsulates water molecules, resulting in the first dispersed system having good fluidity. A second dispersion is prepared using a second thickener. The layered crystal structure of lithium magnesium silicate or magnesium aluminum silicate hydrates and expands upon contact with water. Water molecules enter the interlayer spaces of the lithium magnesium silicate or magnesium aluminum silicate, expanding the interlayer spacing and causing the mineral particles to swell. Under shear force, the expanded layered structure gradually disperses into fine flakes. These flakes overlap through surface charge (electrostatic effects caused by interlayer cations) and intermolecular forces (such as hydrogen bonds and van der Waals forces), forming a continuous three-dimensional network that encapsulates a large number of water molecules. This resulting second dispersion is characterized by high viscosity but significant shear thinning (strong thixotropy) and slow recovery. The first and second dispersions are then mixed to prepare a thickening system. The rigid network of lithium magnesium silicate or magnesium aluminum silicate provides a high-viscosity base, while the flexible chains of microcrystalline cellulose-carboxymethyl cellulose salt improve network recovery. The resulting thickening system exhibits high viscosity, significant shear thinning, rapid thixotropic recovery, and good spreadability. If microcrystalline cellulose, carboxymethyl cellulose salt and the second thickener are directly mixed in one step to prepare a thickening system, since when lithium magnesium silicate or magnesium aluminum silicate is dispersed in water, the layered structure will be negatively charged due to ion exchange, and carboxymethyl cellulose salt (such as sodium carboxymethyl cellulose, CMCNa) is an anionic polymer and also has a negative charge after dissolution, the electrostatic repulsion between the two may hinder the expansion of the interlayers and network interweaving of lithium magnesium silicate or magnesium aluminum silicate, resulting in reduced thickening efficiency. The fibrous structure of microcrystalline cellulose may compete with the layered structure of lithium magnesium silicate or magnesium aluminum silicate for space, destroying the formation of a continuous network. The resulting thickening system exhibits poor thickening effect and a destroyed gel network. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic flow chart of a method for preparing a thickening system according to a specific embodiment of the present application is shown. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. In the following embodiments, many detailed descriptions are intended to enable the present application to be better understood. However, those skilled in the art can readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other materials or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0031] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0032] The serial numbers assigned to the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning.

[0033] The present application provides a method for preparing a thickening system.

[0034] Figure 1 A schematic flow chart of a method for preparing a thickening system according to a specific embodiment of the present application is shown.

[0035] like Figure 1 As shown, in a specific embodiment, the method for preparing a thickening system may include: preparing a first dispersed system (step S1), preparing a second dispersed system (step S2), and preparing a thickening system (step S3).

[0036] In a specific embodiment, preparing the first dispersed system may include: dispersing a first thickener and a first solvent at a first temperature and a first speed for a first time to obtain the first dispersed system.

[0037] In one embodiment, the first thickening agent includes microcrystalline cellulose and a carboxymethyl cellulose salt. It should be noted that the carboxymethyl cellulose salt (CMC) is a water-soluble anionic cellulose ether with carboxyl groups on the molecular chain, which is easily dissolved in water and forms a viscous solution. The molecular chains interact with each other through hydrogen bonds and electrostatic repulsion. The CMC molecular chains interweave and entangle, and can wrap water molecules to form a gel structure with a certain elasticity. Microcrystalline cellulose (MCC) can disperse into small fibrous aggregates in water, and form a loose network structure through hydrogen bonds and mechanical entanglement. Its role is more inclined to "skeletal support", which can enhance the mechanical strength and stability of the system. CMC and MCC can synergistically form a gel. CMC provides water solubility and viscosity, and the molecular chain fills in the network structure of MCC and is combined with the surface of MCC through hydrogen bonds. The small crystals of MCC act as "physical crosslinking points" to enhance the rigidity of the overall structure and reduce the flow of the system. The two work together to form a more dense and stable three-dimensional network, which wraps water molecules therein, and finally forms a gel with viscosity and certain hardness.

[0038] In one embodiment, preparing the second dispersion system can include dispersing the second thickening agent and the second solvent at a second speed for a second time at a second temperature to obtain the second dispersion system.

[0039] In one embodiment, the second thickening agent includes at least one of lithium magnesium silicate and magnesium aluminum silicate. It should be noted that lithium magnesium silicate and magnesium aluminum silicate are a kind of layered silicate minerals, which have a layered crystal structure and contain exchangeable cations between layers. Taking lithium magnesium silicate as an example, when it comes into contact with water, the following processes occur: hydration and swelling: water molecules enter the interlayer space of lithium magnesium silicate, expand the interlayer spacing of the crystal, and cause the mineral particles to swell (the swelling ratio can reach several tens of times the original volume); sheet dispersion: the swollen layered structure gradually disperses into small flakes under the action of shear force (such as stirring), and is uniformly dispersed in water; three-dimensional network formation: the dispersed flakes are connected by surface charges (static electricity caused by interlayer cations) and intermolecular forces (such as hydrogen bonds and van der Waals forces), forming a continuous three-dimensional network structure that encapsulates a large number of water molecules, and finally forms a semi-solid gel.

[0040] In a specific embodiment, the first dispersion system and the second dispersion system are both gel systems. In other words, two gel systems are prepared separately, and then mixed to obtain the thickening system of the present application. It should be noted that a gel system is a special colloidal dispersion system composed of dispersed phase and dispersion medium, and its core feature is to have a three-dimensional network structure, which can wrap a large amount of liquid in the network to form a semi-solid jelly-like substance. The core composition and structure of the gel system are as follows: ① three-dimensional network structure (skeleton): formed by the dispersed phase through chemical bonds (such as covalent bonds), physical forces (such as hydrogen bonds, van der Waals forces, and hydrophobic interactions), or cross-linking. ② dispersion medium (filling phase): liquid wrapped by the network structure, which accounts for most of the gel system.

[0041] In a specific embodiment, the carboxymethyl cellulose salt can include at least one of sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, ammonium carboxymethyl cellulose, and calcium carboxymethyl cellulose.

[0042] In a specific embodiment, the first solvent can include at least one of water, glycerin, propylene glycol, PEG-8, and sorbitol.

[0043] In a specific embodiment, the second solvent can include at least one of water, glycerin, propylene glycol, PEG-8, and sorbitol.

[0044] In a specific embodiment, the first temperature is 0℃ to 80℃. Preferably, the first temperature is 25℃ to 65℃.

[0045] In a specific embodiment, the first speed is 500rpm to 20000rpm. Preferably, the first speed is 1000rpm to 3000rpm.

[0046] In a specific embodiment, the first time is 5 minutes to 60 minutes. Preferably, the first time is 10 minutes to 30 minutes.

[0047] In a specific embodiment, the second temperature is 0℃ to 80℃. Preferably, the second temperature is 25℃ to 65℃.

[0048] In a specific embodiment, the second speed is 500rpm to 20000rpm. Preferably, the second speed is 1000rpm to 3000rpm.

[0049] In a specific embodiment, the second time is 5 minutes to 60 minutes. Preferably, the second time is 10 minutes to 30 minutes.

[0050] In a specific embodiment, the third temperature is 0℃ to 80℃. Preferably, the third temperature is 25℃ to 65℃.

[0051] In one embodiment, the third speed is 200 rpm to 20,000 rpm. Preferably, the third speed is 200 rpm to 3,000 rpm.

[0052] In one embodiment, the third time is 2 minutes to 60 minutes. Preferably, the third time is 2 minutes to 10 minutes.

[0053] In one embodiment, the first dispersion system can include 0.3 to 16 parts by mass of microcrystalline cellulose. For example, the first dispersion system can include 0.3 parts, 0.5 parts, 1 part, 5 parts, 10 parts, 15 parts, or 16 parts by mass of microcrystalline cellulose.

[0054] In one embodiment, the first dispersion system can include 0.1 to 2 parts by mass of a carboxymethyl cellulose salt. For example, the first dispersion system can include 0.1 parts, 0.5 parts, 1 part, 1.5 parts, or 2 parts by mass of a carboxymethyl cellulose salt.

[0055] In one embodiment, the first dispersion system can include 2 to 70 parts by mass of a first solvent. For example, the first dispersion system can include 2 parts, 5 parts, 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, or 70 parts by mass of a first solvent.

[0056] In one embodiment, the second dispersion system can include 0.3 to 2 parts by mass of a second thickening agent. For example, the second dispersion system can include 0.3 parts, 0.5 parts, 1 part, 1.5 parts, or 2 parts by mass of a second thickening agent.

[0057] In one embodiment, the second dispersion system can include 3 to 70 parts by mass of a second solvent. For example, the second dispersion system can include 3 parts, 5 parts, 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, or 70 parts by mass of a second solvent.

[0058] In one embodiment, the mass ratio of the first dispersion system to the second dispersion system can be 0.5 to 2 when the thickening system is prepared. For example, the mass ratio of the first dispersion system to the second dispersion system can be 0.5, 1, 1.5, or 2 when the thickening system is prepared.

[0059] In one embodiment, the thickening system includes 0.3 to 16 parts by mass of microcrystalline cellulose, 0.1 to 2 parts by mass of a carboxymethyl cellulose salt, 0.3 to 2 parts by mass of a second thickening agent, and 10 to 80 parts by mass of a solvent, the solvent including a first solvent and a second solvent.

[0060] The present application also provides a thickening system. The thickening system can be used to prepare an oral care composition, such as a tube toothpaste, a pump toothpaste.

[0061] In an embodiment, the thickening system is prepared by the method of preparing a thickening system described above.

[0062] In an embodiment, the thickening system comprises a first dispersion system and a second dispersion system. The first dispersion system comprises microcrystalline cellulose, a carboxymethyl cellulose salt, and a first solvent. The second dispersion system comprises a second thickening agent and a second solvent.

[0063] In an embodiment, the thickening system has good thixotropy. It has the characteristics of high viscosity, obvious shear thinning, fast thixotropic recovery, and good spreadability.

[0064] The present application also provides an oral care composition. The oral care composition employs the thickening system described above.

[0065] In an embodiment, the oral care composition can comprise the thickening system.

[0066] In an embodiment, the oral care composition can further comprise an abrasive and a foaming agent.

[0067] In an embodiment, the abrasive can comprise at least one of the following: silicon dioxide, hydrated silica, calcium carbonate, dicalcium phosphate, dicalcium phosphate dihydrate, calcium pyrophosphate, aluminum hydroxide.

[0068] In an embodiment, the foaming agent can comprise at least one of the following: sodium lauryl sulfate, cocamidopropyl betaine, sodium lauroyl sarcosinate, disodium lauroyl glutamate, disodium cocoyl glutamate, sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, and sodium cocoyl methyl taurate.

[0069] In an embodiment, the oral care composition can comprise 50-80 parts by mass of the thickening system. For example, the oral care composition can comprise 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, or 80 parts by mass of the thickening system.

[0070] In an embodiment, the oral care composition can comprise 10-50 parts by mass of the abrasive. For example, the oral care composition can comprise 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, or 50 parts by mass of the abrasive.

[0071] In a particular embodiment, the oral care composition can include 0.5 to 5 parts by mass of the effervescent agent. For example, the oral care composition can include 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, or 5 parts by mass of the effervescent agent.

[0072] In a particular embodiment, the oral care composition can include, by mass parts: 0.3 to 16 parts of the microcrystalline cellulose, 0.1 to 2 parts of the carboxymethylcellulose salt, 0.3 to 2 parts of the second thickening agent, 10 to 50 parts of the abrasive, 0.5 to 5 parts of the effervescent agent, 10 to 80 parts of the solvent, wherein the solvent includes the first solvent and the second solvent.

[0073] In a particular embodiment, the oral care composition can further include a humectant. The humectant includes at least one of water, glycerin, propylene glycol, PEG-8, and sorbitol.

[0074] In a particular embodiment, the oral care composition can further include a solubilizing agent. The solubilizing agent includes at least one of polyvinylpyrrolidone and a non-ionic surfactant. The non-ionic surfactant includes at least one of glyceryl undecylenate, glyceryl isostearate, glyceryl oleate, polyglyceryl-2 oleate, polyglyceryl-2 isostearate, polyglyceryl-2 oleate, polyglyceryl-6 laurate, polyglyceryl-6 myristate, polyglyceryl-6 oleate, polyglyceryl-6 ricinoleate, polyglyceryl-10 laurate, polyglyceryl-10 isostearate, polyglyceryl-10 oleate, polyglyceryl-10 diisostearate, polyglyceryl-10 trioleate, polyglyceryl-10 penta isostearate, polyglyceryl-10 pentaoleate, polyglyceryl-10 heptaoleate, polyglyceryl-10 decaisostearate, polyglyceryl-10 decaoleate, polyglyceryl-10 ricinoleate, PEG-5 glyceryl oleate, PEG-15 glyceryl oleate, sorbitan isostearate, sorbitan sesquiisostearate, sorbitan sesquioleate, sorbitan trioleate, sorbitan octanoate, sorbitan oleate, sorbitan laurate, polysorbate-20, polysorbate-60, polysorbate-80, polysorbate-85, PEG-8 diisostearate, PEG-20 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, laureth-4, laureth-9, oleyl polyethyleneglycol-2, oleyl polyethyleneglycol-3, oleyl polyethyleneglycol-7, oleyl polyethyleneglycol-10, and oleyl polyethyleneglycol-15.

[0075] In a specific embodiment, the oral care composition can further include a sweetener. The sweetener can include at least one of xylitol, sorbitol, mannitol, isomalt, lactitol, maltitol, isomaltulose, hydrogenated starch hydrolysate, erythritol, maltotriitol, aspartame, advantame, sodium saccharin, sucralose, neotame, acesulfame, alitame, steviol glycosides, arabitol, and momordica grosvenori. The sweetener can also be selected from other edible grade substances, which are not listed herein.

[0076] In a specific embodiment, the oral care composition can further include a flavorant. At least one of marine flavor, peach flavor, tea flavor, bergamot flavor, eucalyptus flavor, citrus flavor, lemon flavor, peppermint flavor, mint flavor, menthol, licorice flavor, wintergreen flavor, coffee flavor, vanilla flavor, lime flavor, apple flavor, peach flavor, mango flavor, cherry flavor, blueberry flavor, strawberry flavor, cola flavor, cinnamon flavor, clove flavor, and watermelon flavor. The flavorant can also be other kinds of flavors that can be used in the oral cavity, which are not listed herein.

[0077] In a specific embodiment, the oral care composition can further include a cooling agent. The cooling agent can include at least one of menthol, menthol derivatives, WS-3, and WS-23.

[0078] In a specific embodiment, the oral care composition can further include a colorant. The colorant can be an edible colorant.

[0079] In a specific embodiment, the oral care composition can further include a whitening agent. The whitening agent includes titanium dioxide.

[0080] In a specific embodiment, the oral care composition has good thixotropy. It has the characteristics of high viscosity, obvious shear thinning, fast thixotropic recovery, and good spreadability.

[0081] In one embodiment, the oral care composition has good shear thinning property. The oral care composition has a viscosity of 30,000 cps to 120,000 cps at a shear condition of 5 rpm (low shear condition) and a viscosity of 0.2,000 cps to 3,000 cps at a shear condition of 50 rpm (high shear condition). For example, the oral care composition can have a viscosity of 30,000 cps, 35,000 cps, 40,000 cps, 45,000 cps, 50,000 cps, 55,000 cps, 60,000 cps, 65,000 cps, 70,000 cps, 75,000 cps, 80,000 cps, 85,000 cps, 90,000 cps, 95,000 cps, 100,000 cps, 105,000 cps, 110,000 cps, 115,000 cps, or 120,000 at a shear condition of 5 rpm and a viscosity of 0.2,000 cps, 0.3,000 cps, 0.4,000 cps, 0.5,000 cps, 0.6,000 cps, 0.7,000 cps, 0.8,000 cps, 0.9,000 cps, 1,000 cps, 1.1,000 cps, 1.2,000 cps, 1.3,000 cps, 1.4,000 cps, 1.5,000 cps, 1.6,000 cps, 1.7,000 cps, 1.8,000 cps, 1.9,000 cps, 2,000 cps, 2.1,000 cps, 2.2,000 cps, 2.3,000 cps, 2.4,000 cps, 2.5,000 cps, 2.6,000 cps, 2.7,000 cps, 2.8,000 cps, 2.9,000 cps, or 3,000 at a shear condition of 50 rpm.

[0082] In one embodiment, the oral care composition has good stand recovery property.

[0083] In other words, the oral care composition has good extrusion property when extruded and can quickly recover to a good stand after extrusion.

[0084] In one embodiment, the oral care composition has a thixotropic loop area of ≥ 800 Pa·s. Further, the oral care composition has a thixotropic loop area of 800 Pa·s to 2,000 Pa·s. For example, the oral care composition has a thixotropic loop area of 800 Pa·s, 900 Pa·s, 1,000 Pa·s, 1,100 Pa·s, 1,200 Pa·s, 1,300 Pa·s, 1,400 Pa·s, 1,500 Pa·s, 1,600 Pa·s, 1,700 Pa·s, 1,800 Pa·s, 1,900 Pa·s, or 2,000 Pa·s.

[0085] The present application also provides a method for preparing the oral care composition, comprising: obtaining the thickening system as described above, adding other materials to the thickening system, mixing uniformly, and degassing to obtain the oral care composition. The other materials can include abrasives, foaming agents, humectants, and the like.

[0086] In one embodiment, the mixing of the thickening system and other materials in the method of preparing the oral care composition is carried out at a temperature of 20-40°C. The mixing speed can be 800-1500 rpm. The mixing time can be 20-40 minutes.

[0087] The present application also provides a pump toothpaste. The pump toothpaste is a product form designed for dispensing toothpaste by pressing the pump head, which has a more convenient and sanitary use experience compared with the traditional squeezeable tube package.

[0088] In one embodiment, the pump toothpaste comprises a container body and a pump head connected to the container body. The container body is configured to contain the oral care composition described above. The pump head is configured to pump the oral care composition out of the container body under the action of pressing. In one embodiment, the structure of the pump toothpaste can be the existing pump toothpaste structure on the market.

[0089] The present application will be further described in detail through the specific experimental process and experimental data examples. The following examples are only for further illustration of the present application and should not be understood as limiting the present application. In the present examples, unless otherwise specified, the reagents and instruments used are ordinary commercially available, and the experimental operations are carried out according to the product instructions and conventional experimental specifications.

[0090] I. Thickening system

[0091] Experiment 1: Take 2g of microcrystalline cellulose and sodium carboxymethyl cellulose complex (item number: EN268), the mass ratio of microcrystalline cellulose and sodium carboxymethyl cellulose in the complex is 80:20; take 98g of water; disperse uniformly at 25°C using a high-speed disperser at a dispersion rate of 2000 rpm for 15 minutes. The thickening system of experiment 1 is obtained.

[0092] Experiment 2: Take 2g of lithium magnesium silicate and 98g of water, disperse uniformly at 25°C using a high-speed disperser at a dispersion rate of 2500 rpm for 20 minutes. The thickening system of experiment 2 is obtained.

[0093] Experiment 3: Take 1g of microcrystalline cellulose and sodium carboxymethyl cellulose complex (the mass ratio of microcrystalline cellulose and sodium carboxymethyl cellulose is 80:20), 1g of lithium magnesium silicate and 98g of water, add to the mixing equipment, disperse uniformly at 25°C using a high-speed disperser at a dispersion rate of 2000 rpm for 5 minutes. The thickening system of experiment 3 is obtained.

[0094] Experiment 4: Take 50g of the thickening system of experiment 1, take 50g of the thickening system of experiment 2, mix, disperse at 25°C at a dispersion rate of 2000 rpm for 5 minutes, and obtain the thickening system of experiment 4.

[0095] The viscosity of the thickening system of Experiment 1 to Experiment 4 under different shear conditions was tested to evaluate the shear thinning ability of different thickening systems, and the results are as follows:

[0096]

[0097] From the above test results, the thickening system of Experiment 4 has a high initial viscosity and a rapid decrease in viscosity under the condition of increasing shear force, and has good shear thinning ability. Mixing microcrystalline cellulose, sodium carboxymethyl cellulose and magnesium lithium silicate together can have mutual interference effect. Microcrystalline cellulose and sodium carboxymethyl cellulose synergistically thicken with magnesium lithium silicate to achieve the ideal state of shear thinning.

[0098] The principle analysis is as follows:

[0099] The swollen microcrystalline cellulose particles in the thickening system of Experiment 1 can act as a "rigid skeleton" to provide mechanical strength and network nodes, reducing the free movement of carboxymethyl cellulose sodium molecular chains. Carboxymethyl cellulose sodium plays a flexible filling role: water-soluble polymer chains are wound around the surface and gaps of microcrystalline cellulose particles, and the network crosslinking degree is enhanced through hydrogen bonding (hydroxyl groups on the surface of microcrystalline cellulose and carboxyl groups of carboxymethyl cellulose sodium) and electrostatic interaction, forming a "rigid particle-flexible chain" composite network that is more stable than a single component network. Microcrystalline cellulose absorbs water through physical adsorption, and carboxymethyl cellulose sodium binds water through chemical groups (hydroxyl and carboxyl groups), and the two can synergistically improve the water holding capacity of the system, reduce water loss, and indirectly enhance the thickening effect. The thickening system of Experiment 1 shows: viscosity depends on concentration, shear thinning is not obvious (thixotropy is weak), but the flowability is good.

[0100] In the thickening system of Experiment 2, the magnesium lithium silicate layers dispersed in water are uniformly distributed due to mutual repulsion of the surface negative charge, but the edge positive charge and the surface negative charge can form a "card house" structure through electrostatic attraction, i.e. the layers are crosslinked in an edge-surface manner to form a three-dimensional network of colloidal network. The thickening system of Experiment 2 shows: high viscosity but too obvious shear thinning (strong thixotropy), slow recovery speed.

[0101] The thickening system of Experiment 3, magnesium lithium silicate (inorganic clay thickening agent), when dispersed in water, will be negatively charged due to ion exchange, forming a stable colloidal network. Carboxymethyl cellulose salt (such as sodium carboxymethyl cellulose, CMCNa) is an anionic polymer, which also carries a negative charge after dissolution. The electrostatic repulsion between the two may hinder the interlamination of magnesium lithium silicate and the interweaving of the network, resulting in a decrease in thickening efficiency. Microcrystalline cellulose (MCC) is not charged, but its fibrous structure may compete with the layered structure of magnesium lithium silicate for space, disrupting the formation of a continuous network. The thickening system of Experiment 3 exhibits poor thickening effect and gel network destruction.

[0102] The thickening system of Experiment 4: After microcrystalline cellulose and sodium carboxymethyl cellulose form a gel, magnesium lithium silicate is added to form a gel, and then mixed. After mixing, the rigid network of magnesium lithium silicate provides a high viscosity base, and the flexible chains of microcrystalline cellulose-carboxymethyl cellulose salt can improve network recovery. The thickening system of Experiment 4 exhibits high viscosity, obvious shear thinning, rapid thixotropic recovery, and good spreadability.

[0103] II. Oral care composition

[0104] (1) Oral care compositions prepared with different thickening systems:

[0105] The preparation process steps of the oral composition are as follows: the first step is to prepare the thickening system: mix the thickening agent and the solvent at a temperature of 25°C, at a speed of 2000 rpm, and mix for 20 min; the second step is to prepare the paste: weigh the amount of each formula of the raw material, add the thickening system, use a propeller mixing device to stir at ≤65°C, 1000 rpm for 30 min until the paste is fine and uniform, vacuum degassing, to obtain the toothpaste paste.

[0106] The formula system of each oral care composition is shown in the following table:

[0107]

[0108] The thickening agent 1 is a microcrystalline cellulose and sodium carboxymethyl cellulose complex, and the mass ratio of the microcrystalline cellulose and the sodium carboxymethyl cellulose is 80:20, and the product code is EN268. In experiment 1, the first solvent and the thickening agent 1 are mixed to prepare a thickening system, and then the other components are added to the thickening system to prepare the toothpaste. In experiment 2, the second solvent and the thickening agent 2 are mixed to prepare a thickening system, and then the other components are added to the thickening system to prepare the toothpaste. In experiment 3, two thickening agents (i.e., the thickening agent 1 and the thickening agent 2) are mixed with the solvent to prepare a thickening system, and then the other components are added to the thickening system to prepare the toothpaste. In experiment 4, the thickening agent 1 and the thickening agent 2 are respectively prepared into gels, and then the gels are mixed to form a thickening system. Specifically, 0.5 g of lithium magnesium silicate and 10 g of water (the second solvent) are mixed to prepare a gel, and then the microcrystalline cellulose and the sodium carboxymethyl cellulose complex, water, glycerol and PEG-8 (the first solvent) are mixed to prepare a gel. The two gels are mixed (temperature: 25°C, stirring speed: 2500 rpm, time: 10 min) to obtain a thickening system, and then the other components are added to the thickening system to prepare the toothpaste. The toothpastes prepared in experiments 1 to 4 are respectively stored in the same pump-type toothpaste jar.

[0109] The rheological properties of the toothpastes prepared in experiments 1 to 4 are detected, and the results are shown in the following table.

[0110]

[0111] In this embodiment, the viscosity test method is as follows: a viscosity meter with an automatic lifting frame is selected, a T-shaped No. 95 rotor (T95) is used, a speed of 5 rpm is selected, and the average value of the viscosity of the T-shaped rotor after moving into the toothpaste for 1 min is read. The standing degree is measured by visual scoring, and the standing degree of the toothpaste immediately after being squeezed out is visually scored. Specifically, 1-2 points represent that the toothpaste after being pumped out has basically no standing degree, and the toothpaste collapses; 3-4 points represent that the toothpaste after being pumped out has weak standing degree; 5-6 points represent that the toothpaste after being pumped out has certain standing degree; 7-8 points represent that the toothpaste after being pumped out has good standing degree, and the toothpaste has certain strip shape; and 9-10 points represent that the toothpaste after being pumped out has very good standing degree, and the toothpaste has obvious strip shape. The pump-out force test method is as follows: a hand-operated pressure gauge is used, the sensor head of the pressure gauge is pressed against the center of the pump head of the pump-type toothpaste, and the peak value (unit: N) displayed by the pressure gauge when 2 cm of the toothpaste is pumped out is recorded.

[0112] From the above table, under the same dosage, the single dispersion system of experiment 1 and experiment 2 as thickening system to prepare toothpaste, the prepared toothpaste has low viscosity and poor stiffness; experiment 3 uses a together glue process to compound the gel system, the viscosity and stiffness are lower; the viscosity and stiffness of experiment 4 are increased greatly, but the pump-out force of the final product is still in the comfortable pressing force range (internal standard ≤ 40N), which indicates that the toothpaste of experiment 4 has a rapid viscosity decrease under the action of pump-out shear force, so that the pump-out force is not high, that is, the toothpaste of experiment 4 has good shear thinning performance.

[0113] (2) Study on the ratio of thickening system:

[0114] The thickening system is prepared by separately preparing a gel of microcrystalline cellulose carboxymethyl cellulose sodium complex and magnesium lithium silicate and then mixing them. As shown in the following table, different concentrations of components of the thickening system are designed to prepare oral care compositions and test their rheological properties, as follows:

[0115]

[0116]

[0117] Among them, the viscosity test method, stiffness test method and pump-out force test method are the same as before.

[0118] The thixotropic loop area test method is as follows: DHR-3 rotary rheometer, TA Instruments; test fixture: 25 mm flat plate. The test is carried out at room temperature (25±1℃), the sample to be tested is evenly loaded into the measurement system of the rheometer, and the test is carried out according to the instrument operation manual. The larger the thixotropic loop area, the more significant the thixotropy—the material is more prone to structural damage under shear force (stress rise in loading section), and the structure has strong recovery ability after unloading (stress hysteresis in unloading section), showing obvious “shear thinning, static recovery” characteristics; on the contrary, the thixotropy is weak, the structure is less affected by shear, and the recovery is not obvious (close to the straight line characteristics of pure viscous fluid).

[0119] The test method of the texture data is as follows: using CTX texture meter, test type: compression test, pre-test speed: 1.0 mm / s, trigger force: 1 g, test speed: 1.0 mm / s, test distance: 10.0 mm, post-test speed: 1 mm / s. The texture data (Texture Profile Analysis, TPA) of toothpaste is a series of quantitative indexes obtained by physical and mechanical performance test of toothpaste by a texture meter, which is used to describe and evaluate the physical performance and sensory experience of toothpaste in the use process. These data are of great significance for product quality control, formula optimization, new product development and consumer acceptance evaluation. Evaluation of texture data: the same toothpaste body is tested continuously for 2 times, and the peak values of 2 times have no obvious change (within ± 15%), which represents fast shear recovery.

[0120] As can be seen from the above, the thickening system prepared by two-step separately gel-forming process and through appropriate proportioning can be used for preparing toothpaste, and good toothpaste with good standing degree can be obtained, although the viscosity is high, the shear thinning performance is good, the pump-out force is still ≤40 N, and it is suitable for pump type toothpaste.

[0121] The above is a further detailed description of the present application in combination with specific embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, some simple deductions or substitutions can be made without departing from the concept of the present application.

Claims

1. A method for preparing a thickening system, characterized in that: include: Preparing a first dispersion system: dispersing a first thickener and a first solvent at a first temperature and a first speed for a first time to obtain the first dispersion system; wherein the first thickener comprises microcrystalline cellulose and carboxymethyl cellulose salt; Preparing a second dispersion system: dispersing a second thickener and a second solvent at a second temperature and a second speed for a second time to obtain the second dispersion system; wherein the second thickener comprises at least one of lithium magnesium silicate and magnesium aluminum silicate; The thickening system is prepared by dispersing the first dispersed system and the second dispersed system at a third temperature and a third speed for a third time to obtain the thickening system.

2. The preparation method according to claim 1, wherein The carboxymethyl cellulose salt includes at least one of the following: sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, ammonium carboxymethyl cellulose, and calcium carboxymethyl cellulose.

3. The preparation method according to claim 1, wherein The first solvent or the second solvent includes at least one of the following: water, glycerin, propylene glycol, PEG-8, and sorbitol.

4. The preparation method according to claim 1, wherein The first temperature is 0° C. to 80° C.; the first speed is 500 rpm to 20,000 rpm; and the first time is 5 minutes to 60 minutes.

5. The preparation method according to claim 1, wherein The second temperature is 0° C. to 80° C.; the second speed is 500 rpm to 20,000 rpm; and the second time is 5 minutes to 60 minutes.

6. The preparation method according to claim 1, wherein The third temperature is 0° C. to 80° C.; the third speed is 200 rpm to 20,000 rpm; and the third time is 2 minutes to 60 minutes.

7. The preparation method according to any one of claims 1 to 6, characterized in that The first dispersion system comprises, by weight: 0.3 to 16 parts of microcrystalline cellulose, 0.1 to 2 parts of carboxymethyl cellulose salt, and 2 to 70 parts of the first solvent; And / or, the second dispersion system comprises, by weight: 0.3 to 2 parts of the second thickener and 3 to 70 parts of the second solvent.

8. The preparation method according to claim 7, wherein The thickening system comprises, by mass, 0.3 to 16 parts of microcrystalline cellulose, 0.1 to 2 parts of carboxymethyl cellulose salt, 0.3 to 2 parts of the second thickener, and 10 to 80 parts of a solvent, wherein the solvent comprises the first solvent and the second solvent.

9. The preparation method according to claim 1, wherein The first dispersed system is a gel system, and the second dispersed system is a gel system.

10. A thickening system, characterized in that: The thickening system includes a first dispersion system and a second dispersion system, the first dispersion system includes microcrystalline cellulose, carboxymethyl cellulose salt and a first solvent, the second dispersion system includes a second thickener and a second solvent, the second thickener includes at least one of lithium magnesium silicate and magnesium aluminum silicate; Alternatively, the thickening system is prepared by the preparation method according to any one of claims 1 to 9.

11. The thickening system according to claim 10, characterized in that The first solvent or the second solvent includes at least one of the following: water, glycerin, propylene glycol, PEG-8, and sorbitol.

12. The thickening system according to claim 10 or 11, characterized in that The thickening system comprises, by mass, 0.3 to 16 parts of microcrystalline cellulose, 0.1 to 2 parts of carboxymethyl cellulose salt, 0.3 to 2 parts of the second thickener, and 10 to 80 parts of a solvent, wherein the solvent comprises the first solvent and the second solvent.

13. An oral care composition, characterized in that The oral care composition comprises the thickening system prepared by the preparation method according to any one of claims 1 to 9 or the thickening system according to any one of claims 9 to 11.

14. The oral care composition according to claim 13, characterized in that The oral care composition also includes an abrasive and a foaming agent.

15. The oral care composition according to claim 14, characterized in that The friction agent includes at least one of the following: silicon dioxide, hydrated silica, calcium carbonate, calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, calcium pyrophosphate, and aluminum hydroxide.

16. The oral care composition according to claim 14, characterized in that Calculated by weight, the oral care composition comprises: 50 to 80 parts of the thickening system, 10 to 50 parts of the friction agent, and 0.5 to 5 parts of the foaming agent.

17. The oral care composition according to claim 14, characterized in that The oral care composition comprises, by mass, 0.3 to 16 parts of microcrystalline cellulose, 0.1 to 2 parts of carboxymethyl cellulose salt, 0.3 to 2 parts of the second thickener, 10 to 50 parts of the abrasive, 0.5 to 5 parts of the foaming agent, and 10 to 80 parts of a solvent, wherein the solvent comprises a first solvent and a second solvent.

18. The oral care composition according to any one of claims 13 to 17, characterized in that The oral care composition has a viscosity of 30,000 cp to 120,000 cp under a shearing condition of 5 rpm, and a viscosity of 2,000 cp to 30,000 cp under a shearing condition of 50 rpm.

19. The oral care composition according to any one of claims 13 to 17, characterized in that The thixotropic ring area of ​​the oral care composition is ≥800 Pa·s.

20. A pump toothpaste, characterized in that: The pump toothpaste includes a container body and a pump head connected to the container body, wherein the container body is configured to accommodate the oral care composition according to any one of claims 13 to 19, and the pump head is configured to pump the oral care composition out of the container body under pressure.

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