JP5469856B2 - Method for producing dentifrice - Google Patents

Description

  The present invention relates to a method for producing a dentifrice.

  Conventionally, the manufacture of a dentifrice is performed as follows. First, a powder binder is dispersed in a dispersion medium such as polyethylene glycol (PG) in a small tank to form a dispersion, and then the dispersion is added to a water-soluble component solution in a small tank and mixed to swell. Adjust the liquid. Next, the obtained swelling liquid is transferred from the accessory tank to the main compounding tank, and mixed with raw materials such as an abrasive, a color stabilizer, a sweetener, and a fragrance to produce a dentifrice. Thus, by performing operation which disperse | distributes a binder to a dispersion medium, it is preventing that a binder becomes lumps in dentifrice.

  As described above, the toothpaste manufacturing method using the accessory tank is relatively easy to manage individually, and a dentifrice with a stable quality can be obtained. On the other hand, in the multi-product production process, the cleaning operation and the like are inevitably complicated when the product is switched. This labor for changing the product requires a great deal of labor. For this reason, the improvement of the total manufacturing efficiency in the process of multi-product production was calculated | required.

For such problems, a method for producing a dentifrice in which a binder is instantaneously dispersed in water or a wetting agent aqueous solution by a high shear type continuous mixing and dispersing machine to obtain a dispersion, and the dispersion is continuously supplied to a mixer. Has been proposed (for example, Patent Document 1). Also, for example, a dentifrice manufacturing method in which a binder is dispersed in a high-concentration wetting agent aqueous solution using a high shear type continuous mixing and dispersing machine, and the dispersion is continuously supplied to a mixer. Has been proposed (for example, Patent Document 2). Moreover, for example, a method for producing a dentifrice (for example, Patent Document 3) in which a slurry containing a dentifrice raw material is formed and the slurry is deaerated to swell and dissolve the binder, and an unswelled binder A method for producing a dentifrice in which a dispersion and an abrasive slurry are mixed (for example, Patent Document 4) has been proposed.
JP 2008-88145 A JP 2008-88144 A JP 58-208209 A JP 61-236717 A

However, although the above-described method for producing a dentifrice can efficiently produce a dentifrice without causing lumps, there is a problem that the produced dentifrice tends to discolor over time during storage.
Then, this invention aims at the manufacturing method of the dentifrice which can manufacture efficiently the dentifrice which can prevent discoloration during a preservation | save.

  As a result of intensive studies, the present inventors have found that discoloration during storage of a dentifrice is caused by non-uniform dispersion or aggregation of inorganic oxides in the dentifrice when added as a color stabilizer. As a result, they have reached the following inventions.

  That is, the method for producing the dentifrice of the present invention comprises (B) / (A) (mass ratio) = 1/10 to 1/1 of (A) component: inorganic oxide and (B) component: sweetener. And a step of mixing the preliminary mixture with at least one component selected from the group consisting of a binder, a wetting agent, an abrasive, and a foaming agent, a fragrance, and water. It is characterized by. The inorganic oxide is preferably titanium oxide and / or aluminum oxide, and the sweetener is preferably sodium saccharin and / or maltose.

  According to the method for producing a dentifrice of the present invention, a dentifrice that can prevent discoloration during storage can be efficiently produced.

  Hereinafter, although the example is given and demonstrated about the manufacturing method of the dentifrice of this invention, this invention is not limited to this.

[Dentifrice]
The dentifrice produced by the production method of the present invention is selected from the group consisting of (A) component: inorganic oxide, (B) component: sweetener, binder, wetting agent, abrasive, and foaming agent. And at least one component, a fragrance, and water.

<(A) component: inorganic oxide>
(A) component: An inorganic oxide will not be specifically limited if it can mix | blend with a dentifrice as a color tone stabilizer, For example, a titanium oxide, aluminum oxide, etc. are mentioned. (A) A component may be used individually by 1 type and may use 2 or more types together.

The particle diameter of the component (A) is not particularly limited, but for example, the average particle diameter is preferably 0.1 to 0.5 μm. If it is in the said range, it is because (A) component adheres to (B) component so that the surface of (B) component may be coat | covered, and dispersion | distribution of the preliminary mixture to a dentifrice component becomes favorable.
(A) The average particle diameter of a component can be calculated | required with the following method. Using a laser diffraction / scattering particle size distribution analyzer (LA-920, manufactured by HORIBA, Ltd.), distilled water is added to the flow measurement cell, and the component (A) is distilled water so that the absorbance falls within the appropriate concentration range. The average particle diameter of the component (A) can be determined by measuring the volume-based median diameter at 25 ° C. and a relative refractive index of 2.04.

  The blending amount of the component (A) in the dentifrice is preferably determined according to the desired quality of the dentifrice. For example, 0.1 to 1% by mass of the total mass of the dentifrice is preferable, and 0.2 to 0.9 mass% is more preferable. If it is less than the above lower limit, the color tone stabilizing effect of the dentifrice may be insufficient, and if it exceeds the upper limit, the fluidity of the premix or the mixed powder containing it will be reduced. This is because it tends to occur.

<(B) component: sweetener>
(B) component: A sweetener will not be specifically limited if it can be mix | blended with a dentifrice, For example, saccharin sodium, aspartame, stevioside, stevia extract, maltose, lactose, perilartine, a glycyrrhizin salt, neohesperidyl dihydrochalcone, para A methoxy cinnamic aldehyde etc. are mentioned. Among them, saccharin sodium and maltose are preferable, and saccharin sodium is particularly preferable. This is because saccharin sodium and maltose have moderate hydration properties, so that the component (A) tends to adhere to the surface. (B) A component may be used individually by 1 type and may use 2 or more types together.

  Saccharin sodium is a substance typically represented by the following formula (I).

  Maltose is a substance typically represented by the following formula (II).

  Although the particle diameter of (B) component is not specifically limited, For example, an average particle diameter is preferable 500-1500 micrometers, and 800-1500 micrometers is more preferable. If it is less than the lower limit, self-aggregation of the sweetener as the component (B) is likely to occur. As a result, the component (A) cannot adhere to the surface of the individual component (B), the dispersion of the component (A) in the dentifrice becomes insufficient, and the dentifrice is likely to be colored over time. If the upper limit is exceeded, it is classified with other powder components, and uniform mixing becomes difficult.

In addition, the average particle diameter of (B) component can be calculated | required with the following method.
The measurement object (sample) is classified using a 9-stage sieve having a mesh opening of 1700 μm, 1400 μm, 1000 μm, 710 μm, 500 μm, 350 μm, 250 μm, 150 μm, and 100 μm and a tray. In the classification operation, a sieve with a small opening is stacked on a tray in the order of a sieve with a large opening, and a sample of 100 g / time is placed on the top of the top 1700 μm sieve. (Made by Iida Seisakusho, tapping: 156 times / min, rolling: 290 times / min), and vibrated for 10 minutes under an atmospheric condition of a temperature of 25 ° C. and a relative humidity of 40%, and then remain on the respective sieves and trays. The collected sample is collected for each mesh and the mass of the sample is measured. Then, when the mass frequency of the tray and each sieve is integrated, the opening of the first sieve where the integrated mass frequency is 50% or more is a μm, and the opening of the sieve that is one step larger than a μm is b μm. The average particle diameter (mass 50%) can be obtained by the following equation (1), where c% is the total mass frequency from the saucer to the aμm sieve and d% is the mass frequency on the aμm sieve (the same applies hereinafter) ).

  The blending amount of the component (B) in the dentifrice can be determined according to the desired quality of the dentifrice and the kind of the sweetener, for example, 0.01 to 5% by mass with respect to the total mass of the dentifrice. It is preferable to determine within the range.

<Binder>
As binders, carrageenan, xanthan gum, sodium polyacrylate, cellulose derivatives such as sodium carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, alginic acid derivatives such as sodium alginate, propylene glycol alginate, gums such as gellan gum, tragacanth gum, caraya gum And synthetic binders such as polyvinyl alcohol, and inorganic viscosity agents such as silica gel, bee gum, laponite, montmorillonite, bentonite and kaolin. These can be used alone or in combination of two or more.
As for the compounding quantity of a binder, 0.1-10 mass% is preferable with respect to the total mass of a dentifrice.

<Abrasive>
As abrasives, silica, potassium hydrogen phosphate, anhydrous, calcium hydrogen phosphate dihydrate, tertiary calcium phosphate, calcium carbonate, calcium pyrophosphate, aluminum hydroxide, anhydrous silicic acid, aluminum silicate, insoluble metallin Examples thereof include sodium acid, tribasic magnesium phosphate, magnesium carbonate, calcium sulfate, bentonite, zirconium silicate, polymethyl methacrylate, and other synthetic resins. These can be used alone or in combination of two or more. In addition, when silica is used as the abrasive, the dentifrice is noticeably discolored (yellowing) over time. For this reason, this invention is suitably applicable to the dentifrice with which a silica is mix | blended.
As for the compounding quantity of an abrasive | polishing agent, 10-50 mass% is preferable with respect to the total mass of a dentifrice.

<Foaming agent>
Examples of the foaming agent include anionic surfactants, nonionic surfactants, and amphoteric surfactants.

  Anionic surfactants include sodium alkyl sulfates such as sodium lauryl sulfate, sodium N-lauroyl sarcosinate, sodium N-acyl sarcosinate such as sodium N-myristoyl sarcosinate, sodium dodecylbenzenesulfonate, hydrogenated coconut fatty acid monoglyceride N-acyl glutamate such as sodium monosulfate, sodium lauryl sulfoacetate, sodium N-palmitoyl glutamate, sodium N-methyl-N-acyl taurate, sodium N-methyl-N-acylalanine, sodium α-olefin sulfonate, etc. Can be mentioned.

  Nonionic surfactants include sugar fatty acid esters such as sucrose fatty acid ester, maltose fatty acid ester and lactose fatty acid ester, sugar alcohol fatty acid esters such as maltitol fatty acid ester and lactitol fatty acid ester, polyoxyethylene sorbitan monolaurate, polyoxy Polyoxyethylene sorbitan fatty acid ester such as ethylene sorbitan monostearate, polyoxyethylene fatty acid ester such as polyoxyethylene hydrogenated castor oil, fatty acid mono or diethanolamide such as lauric acid mono or diethanolamide, myristic acid mono or diethanolamide, sorbitan Fatty acid ester, polyoxyethylene higher alcohol ether, polyoxyethylene polyoxypropylene copolymer, polyoxyethylene polyol Dipropylene fatty acid esters.

Examples of amphoteric surfactants include alkyldimethylaminoacetic acid betaines and fatty acid amidopropyl betaines.
These foaming agents can be used alone or in combination of two or more.
As for the compounding quantity of a foaming agent, 0.1-10 mass% is preferable with respect to the total mass of a dentifrice.

<Wetting agent>
Examples of the wetting agent include glycerin, sorbit, propylene glycol, 1,3-butylene glycol, ethylene glycol, polyethylene glycol (PEG), polypropylene glycol, xylit and the like. These can be used alone or in combination of two or more.
The blending amount of the wetting agent is preferably 5 to 60% by mass with respect to the total mass of the dentifrice.

<Fragrance>
Perfumes include peppermint oil, spearmint oil, anise oil, eucalyptus oil, winter green oil, cassia oil, clove oil, thyme oil, sage oil, lemon oil, orange oil, peppermint oil, cardamom oil, coriander oil, mandarin oil, Lime oil, lavender oil, rosemary oil, laurel oil, camomil oil, caraway oil, marjoram oil, bay oil, lemongrass oil, origanum oil, pine needle oil, neroli oil, rose oil, jasmine oil, iris concrete, absolute Natural fragrance ingredients such as peppermint, absoluteton rose, orange flower; processed fragrance ingredients of these natural fragrance ingredients; menthol, carvone, anethole, cineol, methyl salicylate, cinnamic aldehyde, eugenol, 2-diol, pinene, Known perfume ingredient materials used for oral compositions, such as single perfume ingredients such as octylaldehyde, citral, pregon, carbyl acetate, and anisaldehyde; formulated perfume ingredients such as strawberry flavor and apple flavor can be used. . These can be used alone or in combination of two or more.
The blending amount of the fragrance is preferably 0.1 to 5% by mass with respect to the total mass of the dentifrice.

<Other optional components>
In the dentifrice, a dentifrice active ingredient, an antiseptic, a colorant, a pH adjuster, and the like can be added as optional components.
Active ingredients for dentifrice include sodium monofluorophosphate, sodium fluoride, hinokitiol, cetylpyridium chloride, benzalkonium chloride, triclosan, chlorhexidine salts, enzymes such as dextranase, amylase, protease, lysozyme, mutanase Sodium chloride, ε-aminocaproic acid, tranexamic acid, tocopherols, glycyrrhetinic acids, ascorbic acid and its derivatives and salts thereof, herbal medicines, potassium nitrate, duckweed extract, chamomile, oxon and the like.
The compounding amount of the dentifrice active ingredient is preferably 0.001 to 5% by mass relative to the total mass of the dentifrice.

Examples of the preservative include methyl p-oxybenzoate, butyl p-oxybenzoate, ethyl p-oxybenzoate, propyl p-oxybenzoate, benzoic acid, sodium benzoate and the like.
Examples of the colorant include edible pigments.
Examples of the pH adjuster include sodium hydroxide, sodium hydrogen phosphate, citric acid, sodium citrate and the like.

[Production method]
The method for producing a dentifrice of the present invention comprises a step (premixing step) of mixing the component (A) and the component (B) to obtain a premix, and the premix is combined with a binder, a wetting agent, an abrasive, And a step of mixing with at least one component selected from the group consisting of a foaming agent, a fragrance, and water (main mixing step).

(Preliminary mixing process)
In the preliminary mixing step in the present invention, the (A) component and the (B) component are mixed at (B) / (A) (mass ratio) = 1/10 to 1/1 to obtain a preliminary mixture. .

<Mixing method>
The mixing method of the component (A) and the component (B) in the preliminary mixing step is not particularly limited as long as the powder can be mixed, and examples thereof include a mixing method using a mixer such as a tumbler mixer or a kneader.

  The mixing ratio of the component (A) and the component (B) in the preliminary mixing step is (B) component / (A) component (mass ratio) = 1/10 to 1/1, and 1/10 to 3/4. Is preferable, and 1/10 to 1/2 is more preferable. If it is less than 1/10, the amount of the component (A) that is excessively attached to the surface of the component (B) increases, and the excessive component (A) aggregates with each other, causing lumps in the dentifrice. It becomes easy to do. If it exceeds 1/1, the degree of adhesion of the component (A) on the surface of the component (B) becomes insufficient, and the obtained premixes aggregate with each other, making it difficult to disperse in the dentifrice. This is because it becomes easy to occur.

  The mixing time in the pre-mixing step can be determined in consideration of the types of components (A) and (B), the mixing ratio, the capacity of the mixer, etc., for example, determined in the range of 3 to 15 minutes. Is preferred.

  The degree of adhesion (coverage) of the component (A) to the surface of the component (B) in the premix is preferably 80% or more of the surface area of the component (B), and 90% or more is covered. It is more preferable that the entire surface of the component (B) is completely covered. This is because if the coverage is 80% or more, it can be well dispersed in the dentifrice during the manufacturing process of the dentifrice. In addition, when the coverage is less than 80%, the components (A) that have not been used for coating aggregate with each other, and lumps are easily generated in the dentifrice. The coverage can be observed and calculated using an electron microscope.

(This mixing process)
In this mixing step, the premix obtained in the premixing step is mixed with at least one component selected from the group consisting of a binder, a wetting agent, an abrasive, and a foaming agent, a fragrance, and water.

<Mixing method>
The mixing method in this mixing step is not particularly limited. For example, the premix and at least one component selected from the group consisting of a binder, a wetting agent, an abrasive, and a foaming agent are dispersed in water to swell. Examples include a method of making a liquid (swelling operation) and mixing the swelling liquid with a liquid raw material such as a fragrance and the remainder of the powder raw material (kneading operation).

<Swelling operation>
The swelling operation is an operation of obtaining a swelling liquid by dispersing the premix and at least one component selected from the group consisting of a binder, a wetting agent, an abrasive and a foaming agent in water.
The swelling operation can be performed using, for example, a continuous mixing and dispersing machine as shown in FIGS. FIG. 1 is a schematic diagram of a continuous mixing and dispersing machine 8, and FIG. 2 is an enlarged schematic diagram of a mixer unit 100 of the continuous mixing and dispersing machine 8. As shown in FIG. 1, the continuous mixing and dispersing machine 8 includes a liquid introduction unit 10, a powder supply hopper 20, and a mixer unit 100.

  A liquid channel 12 is connected to the liquid introduction unit 10, and a pump 14 is provided in the liquid channel 12. The liquid flow path 12 is connected to the liquid inlet 18 of the mixer unit 100 via a valve 16. By adjusting the opening degree of the valve 16, the supply speed of the liquid material flowing through the liquid channel 12 is adjusted. The mixer section 100 is provided with a powder supply path 26, and the powder supply path 26 is connected to the powder supply section 22 via a valve 24. The powder supply unit 22 is connected to the powder supply hopper 20. The mixer unit 100 is provided with a discharge port 140, the discharge port 140 is connected to a discharge path 40, and the discharge path 40 is connected to a kneader (not shown).

  The mixer unit 100 includes a rotor 110 and a stator 130 in the mixer chamber 102. The mixer chamber 102 is connected to a decompression device (not shown) so that the inside of the mixer chamber 102 can be adjusted to an arbitrary pressure. The rotor 110 has a rotating shaft 112 at the center thereof, and a plurality of spiral blades 114 are provided on the rotating shaft 112. A circular inner ring wall 117 formed of a large number of comb teeth 116 is provided along the circumferential direction outside the tip of the blade 114. A circular outer ring wall 117 is formed by a plurality of comb teeth 118 along the circumferential direction so that a circular ring-shaped gap 122 is formed between the circular inner ring wall 117 and the circular inner ring wall 117. An annular ring wall 119 is provided, and the blade 114, the circular inner ring wall 117, and the circular outer ring wall 119 rotate together with the rotation of the rotating shaft 112. On the other hand, the stator 130 has a diameter that matches the diameter of the ring-shaped gap 122 in which a large number of comb teeth are formed along the circumferential direction through the intermediate inclined ring wall 134 at the lower peripheral edge of the large-diameter circular ring-shaped substrate 132. A small-diameter circular ring wall 120 having a small diameter is continuously provided, and the small-diameter circular ring wall 120 of the stator 130 is disposed so as to be inserted into the ring-shaped gap 122 of the rotor 110.

  Examples of the continuous mixer / disperser 8 described above include a QuadroWytron ZC0, a QuadroWytron XC type, a QuadroWytron ZC1 type (manufactured by Quadro), a BECOMIX DUO-homogenizer (manufactured by Berenz), and the like. Can be mentioned.

  In the continuous mixing and dispersing machine 8, the positional relationship between the powder supply path 26 and the rotor 110 is not particularly limited, and the axis of the powder supply path 26 and the central axis of the rotor 110 may coincide with each other. It may be. This point will be described with reference to FIG. FIG. 3 is a schematic diagram of the mixer unit 100 for explaining the positional relationship between the powder supply path 26 and the rotor 110. The powder supply path 26 is arranged such that its axis O is shifted from the central axis P of the rotor 110 (hereinafter sometimes referred to as eccentric arrangement). In this way, by arranging the powder supply path 26 eccentrically, the powder raw material supplied from the powder supply path 26 can be efficiently mixed and dispersed in the liquid raw material supplied from the liquid inflow port 18 without causing lumps. can do. The degree of the eccentric arrangement can be determined in consideration of the amount and type of the powder raw material. For example, when the distance from the central axis P to the axis O of the rotor 110 is “r”, the distance r and the mixer The eccentricity ratio r / R represented by the ratio to the inner radius R of the chamber 102 is preferably 0.2 to 0.5, and more preferably 0.3 to 0.4. When the eccentricity ratio is less than 0.2, the powder raw material is introduced in the vicinity of the rotating shaft 112 of the rotor 110 having a weak centrifugal force. As a result, the residence time of the powder raw material becomes longer, the water-soluble (B) component starts to dissolve in the dispersion medium at an early stage, and the aggregation of the (A) component tends to occur. On the other hand, when the eccentricity ratio exceeds 0.5, the powder raw material is liable to become lumpy in the swelling liquid, which is not preferable.

An example of swelling operation using the continuous mixing and dispersing machine 8 will be described.
With the valves 16 and 24 closed and the pump 14 stopped, the swelling dispersion medium is introduced into the liquid supply unit 10. The powder supply hopper 20 is charged with at least one component selected from a premix and a binder, a wetting agent, a foaming agent, and an abrasive as a powder raw material.

  Next, the pump 14, the powder supply unit 22, and the rotor 110 are started, and the valves 16 and 24 are opened at an arbitrary opening degree. In addition, the pressure reducing device is activated to bring the inside of the mixer chamber 102 to an arbitrary pressure. The powder raw material in the powder supply hopper 20 is supplied into the mixer chamber 102 via the powder supply unit 22 and the powder supply path 26. The swelling dispersion medium in the liquid supply unit 10 is supplied from the liquid inlet 18 into the mixer chamber 102 via the liquid supply path 12, the pump 14, and the valve 16. The powder raw material and the swelling dispersion medium thus supplied into the mixer chamber 102 are agitated and mixed by the rotation of the spiral blade 114 that rotates integrally with the rotation of the rotating shaft 112 of the rotor 110, and the inner ring wall. The fluid flows in the direction 117 and is sheared when passing through the comb teeth 116 and 118 and the comb-shaped gaps of the ring-shaped gap 122, and is discharged as a swelling liquid through the discharge port 140. During this time, since the (A) component is present on the surface of the premix, the penetration of water into the interior is slow, and the (B) component is gradually dissolved in water. As a result, the (A) component adhering to the surface of the (B) component is also gradually dispersed in water, and the (A) component is uniformly dispersed in the swelling liquid without aggregating with each other.

Examples of the swelling dispersion medium include water, an aqueous solution in which a part or all of the wetting agent is dissolved in water, or a solution in which other liquid raw materials such as a fragrance are dissolved. Among these, from the viewpoint of obtaining a dentifrice with stable physical properties, it is preferable to use an aqueous wetting agent solution obtained by dissolving a wetting agent in water as a dispersion medium for swelling.
When a wetting agent aqueous solution is used as the swelling dispersion medium, the mixing ratio of the wetting agent and water is preferably wetting agent / water = 25/75 to 85/15. When the wetting agent / water is less than 25/75, the amount of the wetting agent mixed in the kneading operation described later increases, and the time required for the kneading operation tends to increase. This is because when the wetting agent / water exceeds 85/15, the powder raw material supplied from the powder supply hopper 20 tends to be difficult to swell with water.

  The powder raw material supplied to the powder supply hopper 20 is not particularly limited as long as it includes a premix and at least one selected from the group consisting of a binder, a wetting agent, a foaming agent, and an abrasive. From the viewpoint of obtaining a dentifrice with stable physical properties, it is preferable to include a binder and a wetting agent that easily form lumps.

  The powder raw materials to be input to the powder supply hopper 20 may be individually input to the powder supply hopper 20 or may be mixed in advance (powdered). It is good also as mixed powder by mixing operation. From the viewpoint of the homogeneity of the swelling liquid, it is preferable that the powder raw material charged into the powder supply hopper 20 is mixed in advance to be a mixed powder. The said powder mixing operation is not specifically limited, A well-known powder mixing method can be used, For example, the mixing method using a tumbler mixer is mentioned.

  The supply rate of the powder raw material to the mixer chamber 102 can be determined in consideration of the type and amount of the powder raw material, the type of the dispersion medium for swelling, and the like, for example, determined in the range of 1 to 10 kg / min. It is preferable that it is determined in the range of 3 to 6 kg / min. This is because, within the above range, the swelling liquid can be efficiently produced while preventing generation of lumps of the powder raw material.

  The supply speed of the swelling dispersion medium to the mixer chamber 102 can be determined in consideration of the type and amount of the powder raw material, the type of the swelling dispersion medium, and the like, for example, in the range of 10 to 100 kg / min. It is preferable to determine in the range of 40-80 kg / min. This is because, within the above range, the swelling liquid can be efficiently produced while preventing generation of lumps of the powder raw material.

  The rotational speed of the rotor 110 can be determined in consideration of the supply amount of the powder raw material, the supply amount of the swelling dispersion medium, and the like. For example, the linear speed of the outer periphery of the rotor 110, that is, the tip of the blade 114 is 10. It is preferable to determine in the range of -50 m / s. This is because, within the above range, the swelling liquid can be efficiently produced while preventing generation of lumps of the powder raw material.

  The pressure in the mixer chamber 102 can be determined in consideration of the capability of the powder supply unit 22 and the capability of the mixer unit 100. For example, the pressure is preferably -80 to -5 kPa with respect to atmospheric pressure. . If it is less than the above lower limit value, the powder raw material is supplied in excess of the supply speed of the powder supply unit 22, and the supply amount of the powder raw material into the mixer chamber 102 cannot be accurately controlled. If the upper limit is exceeded, the discharge rate of the powder raw material from the powder supply unit 22 decreases, and the supply amount of the powder raw material into the mixer chamber 102 cannot be accurately controlled.

<Kneading operation>
The kneading operation includes the swelling liquid obtained by the swelling operation, the remainder of the powder raw material added by the swelling operation (residual powder raw material), and the remainder of the liquid raw material added by the swelling operation (residual liquid raw material). To obtain a dentifrice.
Examples of the kneading operation include a method of mixing the swelling liquid, the residual powder raw material, and the residual liquid raw material using a kneader.

  As the kneading machine, a mixing apparatus generally called a kneading machine (see “kneading apparatus” issued by the National Institute of Science and Technology) is used for the purpose of uniformly dispersing the powder in the liquid. The kneader includes a wheel shape, a ball shape, a blade shape, a roll shape, etc. Among them, the blade shape is preferable from the viewpoint of the mixing efficiency of the high viscosity liquid. Examples of the blade-type kneader include a kneader, a paddle mixer, a ribbon mixer, a screw mixer, a spiral mixer, and a planetary mixer. Among these, a kneader, a spiral mixer, and a planetary mixer are more preferable from the standpoint of detergency and efficient mixing and dispersion of a large amount of abrasive. By using such a mixer, even in the production of a high-viscosity dentifrice, it can be efficiently and uniformly mixed. The kneader is preferably a vacuum kneader capable of depressurizing the inside of the mixer in order to defoam the dentifrice component during the kneading operation.

  The mixing procedure in the kneading operation is not particularly limited, and examples thereof include a method in which the swelling liquid is charged into the kneader and then the entire amount of the residual powder raw material and the total amount of the residual liquid raw material are charged into the kneader and mixed. However, from the viewpoint of expressing the flavor of the dentifrice obtained, it is preferable to perform the kneading operation according to the following procedure.

  First, a fragrance is introduced into a kneader into which the entire amount of the swelling liquid has been charged and mixed with the swelling liquid. Next, the abrasive is put into a kneader and mixed with the swelling liquid and the fragrance. At this time, the abrasive is preferably introduced into the kneader after the fragrance, even when the abrasive is added in the form of a slurry. And the whole quantity of the residual powder raw material except a foaming agent and a residual liquid raw material is thrown into a kneader, and it mixes for arbitrary time under reduced pressure. And a dentifrice can be obtained by adding a foaming agent and mixing for arbitrary time under reduced pressure. In this way, since the fragrance can be prevented from adsorbing to the powder raw material by mixing the fragrance with the swelling liquid prior to the residual powder raw material such as an abrasive or a foaming agent, the flavor expression of the resulting dentifrice is improved. It becomes good.

  The temperature in the kneading operation can be determined according to the formulation of the dentifrice, and is preferably determined in the range of 15 to 40 ° C., for example. This is because the time required for the kneading operation can be shortened and the flavor quality can be maintained high within the above range.

  The degree of pressure reduction in the kneading operation is preferably determined in the range of 1 to 10 kPa (absolute pressure), for example. This is because the bubbles in the dentifrice can be efficiently defoamed within the above range.

  As described above, by providing a premixing step in which the (A) component and the (B) component are previously mixed at (B) / (A) (mass ratio) = 1/10 to 1/1, The component A) can be uniformly dispersed in the swelling liquid. As a result, since the discoloration of the dentifrice during storage can be prevented by a simple method of simply mixing the components (A) and (B) in advance, the dentifrice is efficiently produced without requiring complicated steps. be able to.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, it is not limited to an Example.

[Coloring suppression effect]
The coloring suppression effect was confirmed by the following color suppression rate measurement and visual evaluation of the color tone change of the dentifrice after storage at 50 ° C. for 1 month.

(Measurement of coloring suppression rate)
The color tone of the dentifrice at the start of storage (ΔE initial color tone), and the color tone of the dentifrice after storing at 50 ° C. for 1 month (color tone after ΔE storage) were measured. From the following, the coloring suppression rate was calculated by the following equation (2). To measure the color tone of the dentifrice, the dentifrice is filled in the attached cylindrical cell of 30 mmφ, the protruding dentifrice is ground, and ΔE is measured twice using a color difference meter (Spectrophotometer SE2000, manufactured by Nippon Denshoku Industries Co., Ltd.). The average value was measured as ΔE initial color tone or ΔE color tone after storage.

  Coloration inhibition rate (%) = (ΔE color tone after storage−ΔE initial color tone) ÷ ΔE initial color tone × 100 (2)

(Coloring suppression visual evaluation)
Visual evaluation of coloring suppression was conducted by 10 expert panelists using a dentifrice stored for 1 month at refrigeration (0-5 ° C) as a standard product, and visually checking the color tone of the dentifrice stored at 50 ° C for 1 month. evaluated.

<Evaluation criteria>
◎: More than 8 out of 10 people answered that the change in color tone was suppressed compared to the standard product ○: 6-7 or more out of 10 people suppressed the change in color tone compared to the standard product And answer △: 4-5 or more out of 10 responded that the color tone change was suppressed compared to the standard product ×: 3 or less out of 10 responded that the color tone change was suppressed

[Raw materials]
Table 1 shows (A) component: inorganic oxide, (B) component: sweetener, binder, wetting agent, abrasive, foaming agent, and optional components used in Examples and Comparative Examples. About the saccharin sodium and maltose used as (B) component, it processed as follows and the particle diameter was adjusted.

(Saccharin sodium)
The saccharin sodium shown in Table 1 was classified with a sieve so that the average particle size would be 300 μm, 500 μm, 950 μm, 1500 μm, and 1700 μm.

(Maltose)
Maltose shown in Table 1 was dissolved by adding 4 kg of boiled purified water to 1 kg of maltose to prepare an aqueous maltose solution. The maltose aqueous solution was allowed to stand at 25 ° C. for 24 hours, and the precipitated crystals were collected by filtration. Next, the collected crystals were dried under reduced pressure (100 kPa, 25 ° C., 24 hours) to obtain dried crystals. The dried crystals were pulverized using a pulverizer (rotor speed mill P-14, manufactured by Fritsch Japan Co., Ltd.). The crushed crystals were classified with a sieve to obtain maltose having an average particle size adjusted to 950 μm.

[Examples 1-13, Comparative Examples 1-3, 5, 6]
According to the composition of Tables 2 to 5, 50 kg of dentifrice was produced by the following steps.
(Preliminary mixing process)
The component (A) and the component (B) were mixed using a tumbler mixer (TMH-65, manufactured by Seiwa Giken Co., Ltd.) under room temperature and atmospheric pressure conditions to prepare a preliminary mixture. The drum tilt was 45 degrees, the drum rotation speed was 24 rpm, and the mixing time was 10 minutes.

(This mixing process)
<Powder mixing operation>
As a powder mixing operation of this mixing process, the premix obtained in the premixing process, carrageenan, sodium alginate, xylit, and PEG # 4000 were mixed using a tumbler mixer to obtain a mixed powder. . The drum tilt was 45 degrees, the drum rotation speed was 24 rpm, and the mixing time was 10 minutes.

<Swelling operation>
For the swelling operation, a quadroightron ZC0 (manufactured by Quadro), which is a continuous mixing and dispersing machine similar to the continuous mixing and dispersing machine shown in FIGS. Operating conditions of continuous mixer / disperser (distance r from rotor central axis to powder supply path axis, mixer chamber radius R, eccentric ratio r / R, mixer chamber pressure reduction, blade tip linear velocity, mixed powder supply The speed and the dispersion medium supply speed) were as shown in Tables 2 to 5.
According to the composition of “dispersion medium” in Tables 2 to 5, a sorbite aqueous solution (70%), propylene glycol, and water were mixed to obtain a dispersion medium for swelling. The swelling dispersion medium is supplied to the mixer section of the continuous mixing and dispersing machine at the dispersion medium supply speed in the table, and the mixed powder obtained by the powder mixing operation is powdered at the mixed powder supply speed in the table. It supplied to the mixer part from the body supply path, and prepared the swelling liquid at room temperature.

<Kneading operation>
For the kneading operation, a vacuum kneader (Sigma blade type vacuum kneader 60L, manufactured by Kinki Machinery Co., Ltd.) was used as a kneading machine. First, the swelling liquid obtained by swelling operation and the fragrance | flavor were thrown into the kneading machine, and it mixed for 5 minutes. Next, the abrasive was put into a kneader in a powder state and mixed for 5 minutes. Furthermore, all the remaining raw materials except the foaming agent were put into a kneader, mixed for 10 minutes under a pressure of 1 to 10 kPa (absolute pressure), and defoamed. Thereafter, the foaming agent was put into a kneader and mixed for 10 minutes under a pressure of 1 to 10 kPa (absolute pressure) to obtain a dentifrice. In the kneading operation, the rotation speed of the stirring blade of the kneading machine was 40 rpm (stirring blade tip speed: 0.6 m / s). About the obtained dentifrice, the measurement of a coloring suppression rate and coloring suppression visual evaluation are performed, and the result is described in Tables 2-5.

[Example 14]
According to the formulation in Table 4, 50 kg of dentifrice was produced by the following steps.
(Preliminary mixing process)
A premix was obtained in the same manner as in Example 1.

(This mixing process)
In this example, a dentifrice was produced by the following operation using a kneader without providing a swelling operation.
<Powder mixing operation>
A mixed powder was obtained in the same manner as in Example 1 by using the tumbler mixer with the premix obtained in the premixing step, carrageenan, sodium alginate, xylit, and PEG # 4000.

<Kneading operation>
For the kneading operation, a vacuum kneader was used as a kneader. First, in accordance with the formulation shown in Table 4, the entire amount of wetting agent and purified water was charged into a kneader and mixed to obtain a dispersion medium. Next, the mixed powder obtained by the powder mixing operation was put into a kneader and mixed for 10 minutes. Subsequently, the fragrance was put into a kneader and mixed for 5 minutes, and then the abrasive was put in a powder state into the kneader and mixed for 5 minutes. Furthermore, all the remaining raw materials except the foaming agent were put into a kneader, mixed for 10 minutes under a pressure of 1 to 10 kPa (absolute pressure), and defoamed. Thereafter, the foaming agent was put into a kneader and mixed for 10 minutes under a pressure of 1 to 10 kPa (absolute pressure) to obtain a dentifrice. In the kneading operation, the rotation speed of the stirring blade of the kneading machine was 40 rpm (stirring blade tip speed: 0.6 m / s). About the obtained dentifrice, a coloring suppression rate measurement and coloring suppression visual evaluation are performed, and the result is described in Table 4.

[Comparative Example 4]
A dentifrice was obtained in the same manner as in Example 1 except that the component (B) was not added, that is, the component (A) was used alone in the powder mixing operation without providing a preliminary mixing step. About the obtained dentifrice, a coloring suppression rate measurement and coloring suppression visual evaluation are performed, and the result is described in Table 4.

[Comparative Example 7]
A dentifrice was obtained in the same manner as in Example 14 except that the component (B) was not added, that is, the component (A) was used alone in the powder mixing operation without providing a preliminary mixing step. About the obtained dentifrice, the measurement of a coloring suppression rate and visual evaluation of coloring suppression are performed, and the result is described in Table 5.

As shown in the results of Examples 1 to 14 in Tables 2 to 4, a premixing step is provided, and the component (B) and the component (A) are (B) / (A) (mass ratio) = 1/10 to 1/1. Pre-mixed to obtain a pre-mixed mixture, and the pre-mixed mixture with other powder raw materials (binding agent, foaming agent, etc.) and liquid raw materials (water, fragrance), and dentifrice having an excellent coloring suppression effect It was found that an agent was obtained. In addition, it was found from the results of Example 14 that a dentifrice having an excellent coloring suppression effect can be obtained by providing the preliminary mixing step regardless of the mixing method of the main mixing step.
On the other hand, in Comparative Examples 1 to 7 outside the range of (B) / (A) (mass ratio) = 1/10 to 1/1, the color inhibition rate is less than 90%, and the color inhibition visual evaluation is x or Δ. Furthermore, in Comparative Examples 4 and 7 in which the component (B) was not added (preliminary mixing step was not provided), the coloring suppression rate was less than 80%, and the coloring suppression visual evaluation was x.

It is a schematic diagram which shows an example of the continuous mixing disperser used for the manufacturing method of the dentifrice of this invention. It is the schematic diagram which expanded the mixer part 100 of the continuous mixing disperser used for the manufacturing method of the dentifrice of this invention. It is the schematic explaining the positional relationship of the powder supply path and rotor of a continuous mixing disperser used for the manufacturing method of the dentifrice of this invention.

Claims (3)

Component (A): and an inorganic oxide powder, (B) component: a the powder sweetener only (B) / (A) (mass ratio) = 1 / 10-1 / 1 were mixed in the form of powder A premixing step of obtaining a premixed mixture ,
A method for producing a dentifrice, comprising a main mixing step of mixing the preliminary mixture with at least one component selected from the group consisting of a binder, a wetting agent, an abrasive, and a foaming agent, a fragrance, and water. The main mixing step includes an operation of mixing the preliminary mixture with at least one component selected from the group consisting of a binder, a wetting agent, an abrasive, and a foaming agent to form a mixed powder; The method for producing a dentifrice according to claim 1, comprising an operation of dispersing the body in water to obtain a swelling liquid and an operation of mixing the swelling liquid with a fragrance. The average particle diameter of the said (A) component is 0.1-0.5 micrometer, The average particle diameter of the said (B) component is 300-1700 micrometers, The manufacturing method of the dentifrice of Claim 1 or 2.

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