CN1878527A - Precipitated silicas suitable for transparent dentifrices - Google Patents
Precipitated silicas suitable for transparent dentifrices Download PDFInfo
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- CN1878527A CN1878527A CN200380100065.3A CN200380100065A CN1878527A CN 1878527 A CN1878527 A CN 1878527A CN 200380100065 A CN200380100065 A CN 200380100065A CN 1878527 A CN1878527 A CN 1878527A
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Abstract
An abrasive, amorphous precipitated silica is provided that provides excellent abrasive performance, but also has a relatively high degree of transmittance, and an index of refraction that is sufficiently low to allow it to be a component of a transparent toothpaste composition having a relatively high concentration of water. The amorphous precipitated silica composition has a refractive index of less than about 1.4387, a light transmittance of greater than about 48 %; and a Brass Einlehner abrasion value of greater than about 5 mg loss/100,000 rev. A dentifrice having a haze value of less than about 70 may be prepared using this abrasive, amorphous silica.
Description
Background of invention
Precipitated silica is widely used in the manufacturing industry product, and these products all have its purposes to industrial coating and elastomeric material and tire etc. from cosmetics, food.Silicon dioxide is specially adapted in the dentifrice (as toothpaste), as filler, abrasive material and thickening agent.Because its diverse in function, and compare with other dentifrice abrasives and the active ingredient of for example fluoride and so on has higher compatibility, so in toothpaste is filled a prescription the teacher with dentifrice, have strong desire silicon dioxide is joined in the product.
Yet, abrasive silica is joined in the transparent dentifrice and may be not easy very much, although dentifrice is quite attractive to some consumer, and silicon dioxide can allow manufacturing firm bring uniqueness for their product.The difficulty of its preparation is, produce silica containing transparent toothpaste, must guarantee that this silicon dioxide will cooperate with the refractive index of toothpaste matrix, also require this silicon dioxide to have high light transmittance, after mixing dentifrice, also to have the high-efficient grinding performance of cleaning facing.
The refractive index of silicon dioxide will cooperate with the refractive index of toothpaste matrix, to mean that generally the water in the toothpaste must maintain lower content, compare with silicon dioxide, the refractive index of water is much lower usually, and (refractive index of commercially available silicon dioxide is 1.438-1.451, and water is 1.332), the toothpaste moisture content improves as a result, and its refractive index just reduces.Therefore, if want the refractive index of silicon dioxide to cooperate with the refractive index of toothpaste, the concentration of water need be reduced to minimum in the toothpaste.This is bad, because water is the most inexpensive composition of toothpaste, the common content that must improve wetting agent (price is quite high) of content that reduces water remedies.Therefore reduce the moisture content of toothpaste, will increase the unit cost of toothpaste.
Therefore, being engaged in production transparent gel-form formulation of toothpaste teacher must balance such as Several Factors.Silicon dioxide is indispensable component producing aspect the toothpaste effectively clean the teeth, contains the transparency that reduces tooth paste product integral body but add silicon dioxide, and this is because silicon dioxide printing opacity rate is low, the cause that refractive index is high.Therefore, can improve the effect that cleans the teeth though add silicon dioxide, because its refractive index height, requirement reduces the water content of toothpaste, the inevitable concentration that improve wetting agent simultaneously, and the cost of product significantly increases as a result.
From the above, exist the needs to a kind of silica composition, it not only has good abrasiveness always, also will have higher light transmittance, and enough low refractive index can be added in the higher transparent toothpaste prescription of moisture content this silicon dioxide.
Summary of the invention
The present invention relates to a kind of amorphous sediment silicon dioxide, its refractive index is less than about 1.4387, and light transmittance is greater than about 48%.Its Brass Einlehner attrition value loses/100,000 greater than about 5mg to be changeed.
The invention still further relates to not silica containing premix material, its index of refraction is less than 1.442.Also contain the abrasive silica of the about 10 weight % of 0.01 weight %-that have an appointment in this dentifrice, its RDA value is greater than 50.
The invention still further relates to a kind of method of preparation dentifrice, comprise the preparation refractive index less than about 1.442, not silica containing premix material is mixed and made into RDA greater than the clean product of about 50 tooth with silicon dioxide and this premix material then.
The accompanying drawing summary
Just can understand better when in conjunction with the accompanying drawings, reading the detailed description of the summary of the invention of front and better embodiment of the present invention.But should know that the present invention is not limited to the true physical relationships of the table shown in the accompanying drawing.
Fig. 1 is the precipitated silica light transmittance (%) that makes according to the present invention and the graph of a relation of refractive index.
Detailed Description Of The Invention
Except as otherwise noted, all umbers, percent and ratio are all by weight.All bibliographic references of citation are incorporated into this.To narrate some better embodiment below, the silicon dioxide that uses in dentifrice such as the toothpaste can be provided.Though this silicon dioxide is suitable for use in dentifrice most, also can be used in all other consumer products.
" mixture " is meant the combination of two or more materials, and its form for example is suspension, solution, colloidal sol, gel, dispersion or emulsion, but is not limited to these.
" transparent " is meant the energy transmitted light and sees image, like there not being intermediary's material.
" dentifrice " is meant first oral health-care product, the cream of using such as but not limited to toothpaste, dentifrice and denture.
" low structure silica " is meant that oil absorbency is about the earth silicon material of 70-90ml/100g
(also Jing directly is called silicon dioxide SiO to the present invention relates to amorphous low structure precipitated silica compositions
2), in the dentifrice of its adding toothpaste and so on, can increase its cleaning and abrasive characteristic.This abrasive silica can not only be removed chip and remaining pollutant and make clean teeth, and plays the polishing facing.Because its refractive index is lower than most of comparable amorphous silicas that are purchased, and the light transmittance height, so this silicon dioxide of the present invention will not be suitable for preparing the higher low-cost transparent toothpaste of water content.
This abrasive silica that should add sufficient quantity in dentifrice composition makes radioactive dentin abrasion (RDA) value of toothpaste be about 50-200.RDA is less than 80, and the effect that cleans the teeth of toothpaste is too poor, and RDA is greater than 200, and the abrasiveness of its toothpaste is too big, so that the very big danger that destroys dentine along the gums line is arranged.The tooth paste product of buying in the shop now, its RDA is 50-150, meansigma methods is placed in the middle just, and promptly about 100.The RDA value of dentifrice better is at least 50, as 70-120, and 90-110.
The RDA value of toothpaste depends on the hardness (nonferromagnetic substance) and the concentration of used abrasive material in the toothpaste.The measuring method of RDA is seen the article " A Laboratory Method for Assessmentof Dentrifice Abrashy " that is set forth in John J.Hefferren, Jourual of Deutal Res.Vol 55, and No.4 (1976) is among the pp563-573.The abrasiveness of silicon dioxide can be used certified products Einlehner method (below will describe in detail).According to historical data, determined the relational expression between the dioxide-containing silica in RDA value and Einlehner value and the toothpaste, shown in following equation (1).
RDA＝(0.099003×E)+(0.773864×L)+(0.994414×E×L)+(-0.002875E
2)+
(-0.094783×L
2)+(3.417937)
E is the Beass Einlehner milligram loss value of 10% silica slurry in the formula;
L is the weight % content of silicon dioxide in the toothpaste.
For example, if toothpaste contains its Einlehner attrition value of 20 weight % (be a kind of measurement of hardness, will describe in detail below); Be about 6.0 silicon dioxide then the RDA of this toothpaste be about 100.With the silica concentration of about 6.5 weight %, and usefulness is that abrasiveness is bigger, and for example the Einlehner attrition value is 15 silicon dioxide, also can obtain about 100 same RDA value.Add this Einlehner attrition value and be 15 same silica, and concentration can be made the toothpaste of RDA about 280 when being 20 weight %.
Because these the two kinds silicon dioxide with different attrition values are similar on price, so use on the bigger certain cost of silicon dioxide of abrasiveness cheap with low concentration.But unfortunately less silicon dioxide (for example silicon dioxide of Einlehner value about 4.0) the normally transparent character preferable (can cross its higher refractive index and light transmittance) of abrasiveness generally is not suitable for joining in the transparent dentifrice so grind bigger silicon dioxide.
But, developed abrasive amorphous by the present invention, it not only has excellent abrasion performance, and suitable entirely in being added in transparent toothpaste.Specifically be the rpm of control agitator, digestion time, in go into speed, reactor content (final) pH, slurry pH, can make have less refractive index, higher light transmittance, abrasiveness be enough good abrasive silica.
The preparation method of silicon dioxide compositions of the present invention is as follows.The water-soluble of a kind of alkali silicate such as sodium silicate recognized in adding one reactor, and this reactor for example has the agitating device that can obtain homogeneous mixture, and this alkali metal silicate aqueous solution in the reactor is preheated to 65 °-100 ℃.The concentration of this alkali metal silicate aqueous solution is preferably 8.0-35 weight, for example 8.0-15 weight %.This alkali metal silicate aqueous solution better is a sodium silicate, its SiO
2: Na
2The O ratio is 1-3.5, for example 2.5-3.4%.
Add simultaneously to reactor then: (1) acidulant or acid as vitriolic aqueous solution, the aqueous solution as original same alkali silicate in reactor of (2) addition is through being preheated to about 65 °-85 ℃.The concentration of acidulant aqueous acid medium agent is preferably 6-35 weight %, for example 9.0-15 weight %.Add in the time of above-mentioned and continue, reduce to about 5.4-6.4 up to the pH of reactor content.
Adding after acidulant and additional alkali silicate stop, reactor content is heated to 85 °-100 ℃, be incubated 5-60 minute and allows its " digestion ", the pH of reactor content maintenance at this moment is constant.After digestion finishes, reactor content is filtered, excess inorganic salts is removed in washing, until from the conductivity of the washings of silica filter cake less than about 2000 microhms
-1Because the concentration of the inorganic salt by-product in the conductivity of silica filtrate and the filter cake is directly proportional, therefore keep the conductivity of filtrate less than 2000 microhms
-1, inorganic salt in filter cake such as Na
2SO
4Can remain on required low concentration.
Silica filter cake is added water break into serosity, carry out drying with any conventional drying technology such as spray drying then, produce the precipitated silica that contains moisture 3-50 weight %.This precipitated silica can reach the about 5-25 μ of particle diameter m through grinding, as 5-15 μ m.
It is can add in dentifrice compositions such as the toothpaste that this nothing is decided precipitated silica abrasive.
Except containing abrasive ingredients water, dentifrice also can contain several other compositions, as moistening, thickening agent (also claiming binding agent, glue or stabilizing agent sometimes), antibacterial, fluoride, sweetener and cosurfactant.
The effect of wetting agent is dentifrice to be given a kind of quality of mouthfeel, and prevents its exsiccation.Suitable wetting agent has the mixture of former ethylene glycol (multiple different molecular weight), the third two glycerol (glycerol) erithritols, xylitol, sorbitol, mannitol, lactose and hydrogenated starch hydrolysates and these chemical compounds.
Thickening agent is to be used to provide a brood lac knot thing of being stained with in dentifrice composition of the present invention, can stablize toothpaste, in order to avoid looks is separated.Suitable thickening has silicon dioxide thickening agents, starch, the mixture of glycerinum amyli, karayagum, yellow work natural gum, Radix Acaciae senegalis, Ficus elastica, Radix Acaciae senegalis, Xanthan gum, melon and fruit natural gum, a natural gum, antler glue, sodium alginate, agar, pectin, gelatin, fine paper factor, carboxymethyl cellulose, carboxymethyl cellulose, ethoxy, fine paper factor, hydroxypropyl, the fine paper factor of methylol, the fine paper factor of methylol carboxylic propyl group, the fine paper factor of methyl, the fine paper factor of ethyl, the fine paper factor of sulphuric acid and these chemical compounds.The typical content of binding agent is about 0-15 weight % of dentifrice composition.
Can add antibacterial and be used for reducing microorganism to being lower than known harmful content.Suitable antibacterial has benzoic acid, sodium benzoate, Potassium Benzoate, boric acid, oxybenzene compound such as Beta Naphthol 99MIN, menthol, phenol, penta phenol, own phenol, heptan phenol, octyl phenol, hexyl resorcin, chloride laurylpyridine, chlorination Semen Myristicae pyridine, cetyl to fluoridize pyridine, hexadecylpyridinium chloride.Antibacterial is as if the work that exists, and its content better is about the 0.1-5 weight % of dentifrice composition.
Add sweetener in the dentifrice composition, can make product bring joyful mouthfeel to the people, suitable sweetener has glucide (as saccharin sodium, potassium saccharin, Calcium o-benzolsulfimide) cyclamate (as sodium salt, potassium salt, calcium salt), acesulfame potassium, holder Martin (thaumatin), Xin Xisipading (neohisperidin) diamino to look into ketone, glycyrrhizin ammoniated, the sugar of revolving is arranged, levulose, sucrose, mannose and glucose.
Also better contain the fluoride salt in the toothpaste, in order to avoid the generation of dental caries and development.The fluoride salt that is suitable for has sodium fluoride, potassium fluoride, calcium fluoride, zinc fluoride, stannous fluoride, zinc ammonium fluoride, sodium monofluorophosphate.MFP potassium, hydroxide lauryl amine, diethyllaminoethyl hydrofluorination are produced amide, are fluoridized didecyldimethyl ammonium, sarcosine stannous fluoride, glycine potassium fluoride, glycine hydrofluoride, a sodium monofluorophosphate.Typical levels of fluoride salts is about 0.1-5 weight %.
The adding of surfactant can play additional dentifrice and foaming agent effect, can be selected from cationic surfactant, zwitterionic surfactant, non-ionic surface active agent, amphoteric surfactant and cationic surfactant.Cationic surfactant is better, as metal sulfate as the 12 basic sodium sulfate of washing.
The dentifrice that the present invention discloses here also can contain all supplementary elements, as desensibilization agent, healant, other anti-caries agent, vitamin, antibiotic, antienzyme, enzyme, pH controlling agent, oxidant, antioxidant, brightening agent and antiseptic.
At last, except above-mentioned additive, water can also play a part composition equilibrated.Water better is deionized water, and is free from foreign meter.Dentifrice comprises about 13-20 weight % water.
Below will be but non-restrictive example is described the present invention in detail with some are specific.
Embodiment 1-4
In embodiment 1-4, prepared the silicon dioxide that is suitable for dentifrice and other products according to the present invention.Earlier 900kg is contained 14.36 weight % sodium silicate (SiO
2With Na
2O rubs even than being 3.3) aqueous solution add in the reactor, be heated to 82 ℃, insulation is in this temperature in digestion step, the while stirs with 83ppm.Aqueous sulfuric acid (concentration 12.06 weight %) and sodium silicate aqueous solution (concentration 14.36 weight %, mol ratio 3.3 is heated to 75 ℃) are added with the speed of 113 liters/minute and 377 liters/minute respectively simultaneously.Stop to add sodium silicate aqueous solution after 47 seconds, the adding of acid then continues, and pH reduces to 5.8-6.0 until reactor content.Temperature of charge then remains on 93 ℃ at this pH value, for the time 10 minutes.Its conductivity of formation is filtered, is washed to this silica batch be not more than 2000 microhms
-1Filter cake.Again the filter cake water is broken into slurry, its solid content is 32.4%, pH regulator to 7.20.With filter cake spray drying in a spray dryer, the inlet temperature of spray dryer is 690 ℃ then, and outlet temperature is 78 ℃.Spray-dired product is ground to 8-10 μ m.
In embodiment 2-3, prepared the silicon dioxide that is used for dentifrice and other products by the present invention.Earlier 900kg is contained 14.36 weight % sodium silicate (SiO
2With Na
2The mol ratio of O is 3.3) aqueous solution add in one 400 gal reactor, this reactor is equipped with quaterfoil (45 degree) impeller-agitator of A-200 pitch, is heated to 82 ℃, keeps this temperature in digestion step.Stir with the speed shown in the following Table I simultaneously.Sulphuric acid with 12.4 weight % adds with the speed shown in the Table I with the aqueous solution (being heated to 75 ℃) that contains 14.5 weight % sodium silicate (mol ratio 3.3) simultaneously then.Sodium silicate solution be added in 47 minutes after stop, and acid adding continue with same speed, pH reduces to 7.5 until material.Then Suan adding speed be reduced to the 1.0-1.5 liter/minute, reduce to the pH that reaches final until material pH.The pH of this final material is used to be adjusted to required.Material begins digestion step then, and this moment, temperature rose to 93 ℃, and pH maintains final pH in whole digestion step.The time of each embodiment digestion step is listed in the Table I.
After the digestion, silica batch is filtered on a pressure filter, the conductivity that is washed to filtrate is not more than 2000 microhms
-1The filter cake water is broken into slurry.Became filter cake in 5 minutes with the mixing of Cowles agitator, its solid content is listed in the Table I.The pH of filter cake can further add " the slurry pH " that caustic alkali is adjusted to Table I k.With filter cake spray drying (inlet and outlet temperature are as shown in Table I), grind and form the silica composition that mean diameter is about 8.7-9.7 μ m then.
Comparative example 1-2
The described same quadrat method of embodiment 2-3 is used in the preparation of comparative example 1-2, is in the Table I but procedure parameter uses.
Table I
| Agitator rpm | Sodium silicate flow LPM | Acid flow LPM | Digestion time min | The material final pH | Slurry solid content % | Slurry pH | Inlet temperature ℃ | Outlet temperature ℃ | |
| Embodiment 2 | 50 | 12.6 | 3.8 | 10 | 5.8-6.0 | 33.1 | 6.6 | 440 | 76 |
| Embodiment 3 | 50 | 12.6 | 3.8 | 10 | 5.8-6.0 | 36.8 | 6.97 | 390 | 88 |
| Comparative example 1 | 50 | 12.6 | 3.8 | 10 | 6.5-6.7 | 20.8 | 8.8 | 420 | 76 |
| Comparative example 2 | 50 | 12.6 | 3.8 | 40 | 5.8-6.0 | 22.7 | 7.1 | 440 | 76 |
The silica dioxide granule thing of as above making is measured several character, comprise the Einlehner attrition value, oil absorption rate, particle diameter, refractive index, light transmittance (%), brightness.As the first step of measuring refractive index (RI) and light transmittance, prepared the sorbitol/water liquid storage (about 10) of a proportion, the refractive index of these liquid storages is 1.426-1.440.The accurate ratio of required sorbitol/water depends on used concrete sorbitol, determines it by the technical staff who measures.The concentration of sorbitol is generally 49-70 weight % in these solution.In order to measure refractive index, 1 or 2 of various standard solution is placed respectively on the stator of refractometer (Addbe 60 refractometers, model 10450).Cover plate is fixing on the throne.To the light source energising, read the refractive index of each standard solution.The 20cm that is separating
3In the bottle, accurately be weighed into the liquid storage of 0.5 ± 0.01g silicon dioxide and the various corresponding sorbitol/water of 12.0 ± 0.01g.Bottle is acutely swayed the formation silica dispersions, remove the stopper on the bottle, bottle is placed an exsiccator, use the vacuum pump evacuation.
Described dispersion liquid outgased 30 minutes, visual should the degassing fully.Measure the % light transmittance (%T) of 589nm (Spectronic 20D+) immediately by the operating instruction of manufacturing firm.Specifically be that a dispersion liquid is placed a quartzy device, each sample read the %T reading of 589nm on a 0-100 scale.For embodiment 1 and 3, the %T of liquid storage is given into curve with RI, be shown among Fig. 1.The refractive index of silicon dioxide is defined as %T to the very big position on the curve of RI (abscissa value or X-axis value).Y-axis (vertical coordinate) value then is the %T of silicon dioxide greatly.
Beass Einlehner (BE) attrition value is measured with Einlehner AT-100 grinding ceremony.In this test, a Fourdrinier brass wire mesh is weighed, allow it stand the fixedly abrasive action of revolution of 10% aqueous silica suspension rotation one then, measure per 100,000 changes the pyrite milligram number that loses from the Fourdrinier silk screen, as attrition value.This estimates required disposable feed (brass wire mesh, scuff panel, pvc pipe) can be available from Duncan Assowates, Rutland, and the Vermont commodity are called " Einlehner tests auxiliary equipment ".Specific practice is, to brass wire mesh (Phosphos Bronze, P.M.) prepare, promptly the soap lye (0.5%Alconex) with heat cleans under a ultra sonic bath effect, drip wash in current from the beginning then, in the beaker that 150ml water is housed, place ultra sonic bath to carry out drip wash again, in exsiccator, cool off, weigh.When moving, silk screen uses tweezers, in order to avoid skin oil and fat stains.The Einlehner test cylinder is assembled, and scuff panel and the silk screen of weighing (face of red line but not by abradant surface down) are clamped on the throne.This scuff panel can use 20 tests or to heavy wear, the silk screen of weighing then uses once.
10% silica slurry that 100g silicon dioxide and 900g deionized water are mixed with is poured in the Einlehner test barrel.Einlehner pvc pipe is contained on the shaft.5 positions of having compiled number are arranged on the pvc pipe.When estimating, progressively increase the position of pvc pipe at every turn, discards till having used 5 times.The Einlehner beveller installs again, and being arranged to running 87,000 changes.Each test takes 49 minutes.After circulation is finished, take off silk screen, drip wash in current is from the beginning inserted the beaker that water is housed, and beaker was put into ultra sonic bath 2 minutes, uses the deionized water drip wash, and in 105 ℃ of saggars dry 20 minutes then, in exsiccator, cool off, weigh again.Every kind of sample is done two tests, and the result is average, represents with the milligram number loss of 100,000 rotations.Result to 10% slurry can be characterized by 10% pyrite Einlehner (BE) attrition value.
The granule mean diameter is measured with Northrup Micratrac II.Specifically be that a transparent device is passed through in the laser beam projection, the mobile grain flow that floats on a liquid is wherein arranged.Run into particulate light beam to be inversely proportional to the scattered through angles of particle diameter.Photometric detection meter display is measured the luminous flux at several predetermined angulars.Handled with a microcomputer system with the institute proportional signal of telecommunication of photometry flux, obtained particle size distribution passage rectangular histogram.
For measuring brightness value, fine powder is not pressed into ganoid disk, S-5/Be measures with Technidyne brightness instrument.This instrument has a double beam optical system, and sample with 45 degree photo, is the observation reflected light in this system.The method fruit latt is according to tappi test method T452 and T646, and ASTM standard D985.Dusty material is pressed into the disk of thick about 1em, and used pressure enough produces slick smooth disk surfaces, and does not have loose granule, and is also lackluster.
Oil absorbency is measured with the Semen Lini oil mat method of kneading.In this test, oil is mixed with silicon dioxide, mixture is processed on a smooth surface with a spatula, until forming the sub-shape paste of stiff tax.Measure and obtain the required oil mass of paste mixture (shaping of curling) when sprawling, can calculate the oil absorbency of silicon dioxide, this value representation Unit Weight silicon dioxide is saturated to the volume of the required oil of oil suction capacity fully.Computing formula is as follows:
Test result is listed in the Table II
Table II
| Attrition value (mg) | Oil absorption rate (ml/100g) | Refractive index Index | Light transmittance % | Brightness | Mean diameter (μ m) | |
| Embodiment 1 | 5.7 | 90 | 1.4343 | 78 | 95.7 | 9.5 |
| Embodiment 2 | 9.7 | 71 | 1.4350 | 63 | 98.1 | 9.0 |
| Embodiment 3 | 7.3 | 75 | 1.4387 | 58 | 97.4 | 9.7 |
| Comparative example 1 | 13.2 | 75 | 1.4334 | 45 | 96.9 | 9.0 |
| Comparative example 2 | 18.2 | 71 | 1.4358 | 48 | 97.8 | 9.7 |
By Table II as seen, the silicon dioxide of embodiment 1-3 preparation all meets the standard of making transparent toothpaste (by its low refraction number and high light transmittance), and hardness or abrasiveness are enough high, can make the toothpaste of acceptable or good clean performance.Different therewith, comparative example 1 and 2 abrasiveness height (shown in its Einlehner attrition value), refractive index is low, but light transmittance is very low, undesirable.
In order to be presented at the effect in the consumer products, the abrasive silica of embodiment joins in the 4 kinds of different dentifrice compositions (1-4 number) shown in the Table II with powder type.The performance of these compositionss compares with more following dentifrice compositions then: the compositions 5-6 that contains the abrasive silica that connects comparative example 1-2 preparation, contain prior art silica abrasives (Zevdent115, derive from J.M.Huber Corp., Edison, NJ) compositions 7 does not contain the dentifrice composition 8 of abrasive silica.These toothpaste sample method for makings are as follows: mix following component and form first mixture: glycerol and/or sorbitol, Polyethylene Glycol (CARBOWA, from Unoon Carbide Corp., Danbury CT), the fine paper factor (CMC-9M31XF of carboxymethyl, from Aqualon divisoon of HerculesCorp., Wilmington, DE), this first mixture is stirred to each components dissolved.Mix following component and form second mixture: deionized water, saccharin sodium, potassium fluoride, be stirred to each components dissolved.First and second compositionss are mixed, form premix material.
With premix material will go into a Ross blender (model 130LDM, Charles Ross and Co., Haueage, NY) in, silicon dioxide thickening agents and abrasive silica are added in this premix material, it is mixed under no vacuum condition.So take out 30 inches vacuum, each sample mixed 15 minutes adds sodium lauryl sulphate and spice then.The gained mixture reduces condition in mixing velocity and stirred 5 minutes.These 8 kinds of different dentifrice compositions are by following formulation, and amount wherein is unit with the gram.
Table III
| Component | The group branch | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Sorbitol, 70% | 59.707 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Glycerol, 99.5% | 0.00 | 59.743 | 60.870 | 59.296 | 59.030 | 60.568 | 47.556 | 58.055 |
| Deionized water | 19.177 | 19.914 | 20.287 | 19.765 | 19.327 | 20.189 | 15.851 | 19.352 |
| Carbowax 1450 | 4.000 | 4.000 | 4.000 | 4.000 | 4.000 | 4.000 | 4.000 | 4.000 |
| CMC-9M31F | 0.700 | 1.250 | 1.350 | 1.146 | 1.050 | 1.350 | 0.00 | 0.00 |
| Sodium benzoate | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 |
| Saccharin sodium | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 | 0.200 |
| Sodium fluoride | 0.243 | 0.243 | 0.243 | 0.243 | 0.243 | 0.243 | 0.243 | 0.243 |
| Silicon dioxide thickening agents | 8.000 | 8.000 | 8.500 | 8.000 | 8.000 | 8.000 | 0.00 | 16.000 |
| Embodiment 1 abrasive material | 8.000 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Embodiment 2 abrasive materials | 0.00 | 4.500 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Embodiment 3 abrasive materials | 0.00 | 0.00 | 2.400 | 5.200 | 0.00 | 0.00 | 0.00 | 0.00 |
| Comparative example 1 abrasive material | 0.00 | 0.00 | 0.00 | 0.00 | 6.000 | 0.00 | 0.00 | 0.00 |
| Comparative example 2 abrasive materials | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 3.300 | 0.00 | 0.00 |
| Zeodent 1 15 abrasive materials | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 30.000 | 0.00 |
| F&DC Red#2 2.0％ | 0.100 | 0.100 | 0.100 | 0.100 | 0.100 | 0.100 | 0.100 | 0.100 |
| Sodium hexadecyl sulfate | 1.200 | 1.200 | 1.200 | 1.200 | 1.200 | 1.200 | 1.200 | 1.200 |
| Spice | 0.650 | 0.650 | 0.650 | 0.650 | 0.650 | 0.650 | 0.650 | 0.650 |
| Amount to | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
After as above having prepared dentifrice composition 1-8, the character of the relevant toothpaste transparency of following mensuration is as refractive index, transparency and concentration.
The mensuration of refractive index is to get a toothpaste, places on Abbe 60 refractometers (model 10450), directly reads refractive index.
Transparency is that subjectivity is measured.A toothpaste is extruded on the blank sheet of paper that a slice is printed on word content.If can read content fully, give 10 fens, if can not read content, give 1 fen, the content definition and improve, give the intermediate section of 2-9.8 minutes or more than the toothpaste that was considered as good clear in 8 minutes, show that silicon dioxide is transparent.The transparency mark is that 10 toothpaste generally has under the corresponding turbidity value (below seeing for details) in 40, the transparency mark is 9, and the about 50-60 of turbidity value, transparency mark are 8, the about 60-70 of turbidity value.
" turbidity value " of transparent toothpaste determined with a Garder XL-835 tintometer measuring light transmission.Instrument is calibrated by producer's explanation earlier.Secondly two slides (the thick 0.96-1.06mm of size 38 * 75mm) are placed on the flat surfaces.(the thick 3mm of 38 * 75mm has 24 * 47mm hollow region in the spring coated with a lucite shaping piece on the slide glass.Toothpaste is squeezed on this hollow region of lucite shaping piece.Second slide glass placed on the toothpaste and with hands exert pressure, remove excess toothpaste and air.Sample is placed on the transmitted light beam of precalibrated instrument, notes the turbidity value at 3 different samples positions, on average it.The low expression of turbidity value toothpaste is transparent.
The measurement result of refractive index, transparency, turbidity is listed in the Table IV.
Table IV
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| The premix material refractive index | 1.4418 | 1.4408 | 1.4401 | 1.4418 | 1.4409 | 1.4395 | 1.4402 | 1.4400 |
| Toothpaste material refractive index | 1.4461 | 1.4448 | 1.4441 | 1.4448 | 1.4453 | 1.4423 | 1.4417 | 1.4426 |
| The RDA predicted | 50 | 50 | 50 | 100 | 50 | 50 | 100 | 10 |
| The | 10 | 8 | 9 | 8 | 6 | 7 | 1 | 8 |
| Turbidity | 39 | 64 | 53 | 68 | 74 | 69 | 95 | 71 |
Dentifrice composition 7 and 8 is Comparative composition.Dentifrice composition 7 contains the abrasive silica (Zeoden 185) of prior art, and dentifrice composition 8 contains thickener-silica and do not have abrasive silica.By Table IV as seen, dentifrice composition 7 nonferromagnetic substances are fine, but poor transparency, so be not suitable for the high formulation of tooth-paste of transparent water content.The transparency properties of these differences is because the cause of refractive index height (1.4510).The transparency of different for this reason dentifrice compositions 8 is fine, but because of not containing abrasive silica, so its dentifrice performance is not enough fully.
Dentifrice composition 1-4 contains the silicon dioxide by embodiment of the invention 1-3 preparation, has enough or good nonferromagnetic substance as mentioned above, satisfies all technology (by low refractive index and high light transmittance) of making transparent toothpaste.Dentifrice composition 1-4 has fabulous transparency characteristic and can be by being subjected to or good dentifrice performance as a result.
Dentifrice composition 5-6 contains the silicon dioxide of comparative example 1 and 2 preparations.As mentioned above, these silicon dioxide.Abrasiveness height (shown in high Einlehner attrition value), but light transmittance is low.Dentifrice composition 5-6 has acceptable nonferromagnetic substance as a result, but poor transparency.
Those skilled in the art should know, can under the condition that does not depart from extensive novel concept of the present invention described embodiment be changed.Therefore, the invention is not restricted to described specific implementations, but be included in the various modifications in the spirit and scope of the invention that is defined by the following claims.
Claims (14)
1, a kind of abrasiveness precipitated silica, it has:
Refractive index less than 1.4387;
Light transmittance greater than 48%;
Brass Einlehner attrition value greater than 5mg loss/100,000 commentaries on classics.
2, the described silicon dioxide of claim 2, the light transmittance of described silicon dioxide is greater than 60%.
3, the described silicon dioxide of claim 2, the Brass Einlehner attrition value of described silicon dioxide changes greater than 5.5mg loss/100,000.
4, a kind of dentifrice that comprises claim 1 silicon dioxide.
5, the described dentifrice of claim 4 is characterized in that, described dentifrice has the RDA of 50-150.
6, the described dentifrice of claim 4 is characterized in that, this dentifrice comprises 13-20 weight % water.
7, the described dentifrice of claim 4 is characterized in that, this dentifrice is transparent, and turbidity value is less than 70.
8, the described dentifrice of claim 4 is characterized in that, this dentifrice is transparent, and turbidity value is less than 55.
9, a kind of dentifrice, it comprises:
A) basically by non-silicon dioxide thickening agents, go premix material dried up and that be selected from the wetting agent composition of glycerol, sorbitol, Polyethylene Glycol, the refractive index of this premix material is less than 1.442;
B) 0.01-10 weight % abrasive silica;
The RDA of this dentifrice is greater than 50, and turbidity is less than 70.
10, the described dentifrice of claim 9 is characterized in that, described dentifrice is transparent, and turbidity is less than 70.
11, the described dentifrice of claim 9 is characterized in that, described dentifrice is transparent, and turbidity is less than 55.
12, prepare the method for dentifrice, comprise the steps:
A) preparation does not contain silicon dioxide, and refractive index is less than 1.442 premix material;
B) silicon dioxide is mixed with described premix material, form RDA greater than 50 dentifrice.
13, the described method of claim 12 is characterized in that, described dentifrice is transparent, and turbidity value is less than 70.
14, a kind of dentifrice, it comprises
Silicon dioxide, it has the refractive index less than 1.4387, the light transmittance greater than 48%, the Brass Einlehner attrition value that changes greater than 5mg loss/100,000;
13-20% water;
This dentifrice is transparent, and RDA is at least about 50.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/US2003/034285 WO2004045504A2 (en) | 2002-11-15 | 2003-10-28 | Precipitated silicas suitable for transparent dentifrices |
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| CN1878527A true CN1878527A (en) | 2006-12-13 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109316378A (en) * | 2017-07-31 | 2019-02-12 | 好维股份有限公司 | Gel-forming composition for oral care product and the oral care product including the composition |
| CN109846780A (en) * | 2019-03-06 | 2019-06-07 | 叶绿芝生物科技（中山）有限公司 | A kind of liquid tooth paste |
| CN115321549A (en) * | 2022-09-01 | 2022-11-11 | 确成硅化学股份有限公司 | Preparation method of precipitated silicon dioxide for toothpaste thickener |
-
2003
- 2003-10-28 CN CN200380100065.3A patent/CN1878527A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109316378A (en) * | 2017-07-31 | 2019-02-12 | 好维股份有限公司 | Gel-forming composition for oral care product and the oral care product including the composition |
| CN109846780A (en) * | 2019-03-06 | 2019-06-07 | 叶绿芝生物科技（中山）有限公司 | A kind of liquid tooth paste |
| CN115321549A (en) * | 2022-09-01 | 2022-11-11 | 确成硅化学股份有限公司 | Preparation method of precipitated silicon dioxide for toothpaste thickener |
| CN115321549B (en) * | 2022-09-01 | 2024-04-12 | 确成硅化学股份有限公司 | Preparation method of precipitated silica for toothpaste thickener |
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