JPS5815015A - Stabilized calcium dihydrogen phosphate dihydrate for toothpaste - Google Patents

Abstract

PURPOSE:To obtain calcium dihydrogen phosphate dihydrate with superior stability for toothpaste by mixing a mixture of prismatic or platy crystals and flat crystals of calcium dihydrogen phosphate dihydrate with amorphous magnesium phosphate contg. bound water as octahydrate or lower and by pulverizing the resulting mixture. CONSTITUTION:A mixture of prismatic or platy crystals and flat crystals of calcium dihydrogen phosphate dihydrate which is a superior base for toothpaste is stabilized with novel amorphous magnesium phosphate contg. bound water as octahydrate or lower and superior properties as a stabilizer. When the mixture is simply mixed with the magnesium phosphate, a sufficient stabilizing effect is not phroduced, so it is preferable that they are previously pulverized, well mixed, and further pulverized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to Ij1#i stabilized dicalcium dihydrate for use in toothpaste.

Conventionally, distone phosphate R2 hydrate has been used as a toothpaste base material due to its hardness and particle shape.

When used as a toothpaste ingredient as it is, it is partially dehydrated over time and -
When brushing your teeth, it builds up and builds up, causing roughness on your toothbrushing surface, and when it comes out of the tube, the polishing force increases and causes damage to your teeth.If aluminum is used for the tube,
There were problems such as corrosion of the aluminum material. Therefore, in order to prevent dehydration of dicalcium phosphate dihydrate, that is, to provide stability, various stabilizers have been added to the dicalcium phosphate dihydrate, for example, magnesium phosphate, etc. Magnesium salt (US@Patent No. 2018410),
Magnesium phosphate octahydrate is used in %.

The present inventors have discovered that the toothpaste base material and [2] dicalcium phosphate dihydrate and its stabilizer magnesium phosphate,
As a result of repeated research in order to provide even better books, we have made the following separate proposals for each.

That is, regarding the base material dicalcium phosphate R2 hydrate, columnar to plate-shaped dicalcium phosphate dihydrate obtained by reacting an alkali metal phosphate and a calcium salt at pH 2.5 to pH 5, and pF115. It was discovered that hot metal products with flat crystals obtained by reacting at ~&0, preferably those with a mixing ratio of 5:5 to 9:1, were inferior in polishing power and kneading properties by -1. Ta. In addition, the production of columnar to plate-like crystals and flat crystal distone phosphate R2 hydrate ink mixtures has become popular, as well as producing each separately and texture them, as well as alkali metal phosphates and alkali metal phosphates. Calcium salt was added at a reaction temperature of t411°C or lower and pHt-2.5 to A5 in the first stage.
In the second stage, add 7)b potash substance to adjust the pH.
35~! ! We have also found and proposed that a method using LO can be obtained more favorably.

On the other hand, stabilizing magnesium phosphate is superior in terms of manufacturing method and purity compared to anhydrous salt, tetrahydrate salt, aqueous salt, and 22-hydrate salt, which have been known as magnesium phosphate, and is also used as a toothpaste base. We have discovered a novel magnesium monononate which is amorphous and has a bound water content of octahydrate or more, which has an excellent stabilizing effect on dicalcium phosphate dihydrate.
is suggesting. This novel magnesium phosphate can be obtained by heating and dehydrating a 22nd order magnesium phosphate salt obtained by a reaction between an alkali metal phosphate and a magnesium salt.

The present invention uses the above-mentioned toothpaste base material and (7) dicalcium phosphate dihydrate consisting of a mixture of excellent columnar to plate crystals and flat crystals.
The above-mentioned amorphous, which has excellent properties as a stabilizer and I2, and the new magnesium phosphate whose bound water content is less than octahydrate, stabilizes distone diphosphate for toothpaste. It's about salt. This columnar shape of dicalcium phosphate dihydrate
The stabilizing effect of simply mixing plate crystals, coracoid hot metals, and new magnesium phosphate is weak, so it is necessary to crush dicalcium phosphate dihydrate and magnesium phosphate in advance.
Mixed bales are best crushed. The amount of magnesium phosphate added is 1 to 6 weight-1 per dicalcium phosphate dihydrate.
Good (7〈 is 2 to 4 Il, which is strange. If it is less than 1 weight, no stabilizing effect can be obtained, and even if more than 6 weight ginseng is added, no further effect can be expected. This is undesirable because it adversely affects physical properties such as polishing properties and kneading properties of distone phosphate R2 hydrate.

As for the crushing method, a grinding type crusher like a crusher is suitable, and a bottle! When pulverizing is carried out using an impact pulverizer such as a 1 mil, even if thick dicalcium phosphate dihydrate is obtained, this tends to become thinner dicalcium phosphate dihydrate for toothpaste due to the spaces between the bones. The result is a book that is close to the one that was manufactured from the beginning as a flat crystal. In addition, types such as ball mills and vibromills that perform grinding and impact at the same time are undesirable because +I dicalcium phosphate dihydrate adheres to the inner wall of the grinder, greatly reducing the grinding efficiency. In this way, the selection of the type of crusher is important for obtaining the optimum dicalcium phosphate dihydrate for toothpaste.

Next, we will give an example of the production of distone phosphate l1L dihydrate used in the present invention and a new magnesium phosphate, and an example in which nine combinations of these products were investigated.

Production of dicalcium phosphate dihydrateProduction IpH1 A phosphorus salt solution prepared by diluting sodium ammonium hydrogen phosphate (hereinafter referred to as phosphorus salt) produced from wet phosphoric acid with warm water to y%% os and 20% Ca C4. Happy liquid Ca/
p molar ratio t10, reaction temperature jl&! Continuously 1st at 50℃
At the same time, 351ucz@g was added to the reaction tank while adjusting the reaction pH to 2.7, and in the @2 reaction tank, 2oIGca (OH)1 slurry was added to pHtslc.
and continuously obtain a slurry of phosphoric acid-stone R2 hydrate. Then, it was separated from the mother liquor, washed, dehydrated, and dried at 50°C.

This product was mostly #1 thick columnar to plate crystals with an average thickness of 10 to 15 μvm, and some flat crystals with a thickness of 1 to 2 μm. This columnar (plate) crystal,
Akira Zenhira's mixing ratio is 1j8f2. A photograph of this mold cage is shown in Figure 1.

Production Example 2 1J11PmOs phosphorus salt solution and 14*caczl solution were continuously mixed with 111 at a molar ratio of t10 and a reaction temperature of 50°C.
Add to one reaction tank and at the same time! 5511iHCj# In the reaction tank, add so that I is 2.7, and in Kame 2 reaction tank, adjust the pH to 4.5 with 20* NaOH solution. Obtain a slurry of Hereinafter, the same operation as in Production Example 1 was performed.

The same mixing ratio of 6 to 8:2 was obtained here.

Production example S 14'llP Oi phosphorus salt solution and 141G CaCt
s 11 liquid at 0N molar ratio 1.00, reaction temperature 1155℃
s5*Hct@
11 so that the reaction pH becomes 55, and further, in the second anti-calcium slurry, a slurry of 20111 acid dicalcium dihydrate is obtained. Hereinafter, the same operations as in Production@1 were performed.

The mixing ratio was 6:4.

Production example 4 (comparative production example) 14'Ik Pros phosphorus salt solution and 1a% Ca
A ctMII case was added to the reaction tank at a λ molar ratio of L1G and a reaction temperature of 50°C, and at the same time 55 Rumor I (ct B solution with a reaction pH of 2
-7 to obtain a continuous lime dihydrate slurry. Next, the mother liquor was separated, washed, and dehydrated for 50 min.
This product, which was dried at .degree. C., contained only columnar to plate-like crystals having an average thickness of about 10 to 15 .mu.m. A mirror photograph of this mold is shown in Figure 2.

Manufacturing example 5 (comparative manufacturing f1) The reaction pH was set to 4.5 by the same operation as in Production Example 4.

The obtained crystals were only flat crystals with an average thickness of 1 to 2 μm. This micrograph is shown in FIG.

Production Example of Stabilizer Magnesium Phosphate 6 10㎾ Bulky Sodium Phosphate @i [K 1o % Magnesium Sulfate S* is reduced so that the M/P molar ratio is 15, and at this time pFl is 9 or less ni1:! At the same time, 5N sodium hydroxide was added dropwise to prevent the mixture from leaking. In addition,
The reaction temperature was 35°C and the reaction time was 1 hour. Generate &S
Large crystals of 0 to 150μ were filtered, washed, and dried at 40°C. This product showed the x*#A fold pattern shown in FIG. 4 (5), and was confirmed to be magnesium phosphate 22-hydrate. Next, drying 1. Take 100 grams of 22-hydrate salt of Macnesium phosphate in bulk and dry in an internal heat dryer.
I shouted water at 50℃ for 10 minutes.

The dehydrated product was extracted with a weight of Fi 62f, and analysis revealed that it had a composition of octahydrate. In addition, the xm diffraction pattern of the dehydrated product was shown in Figure (1) f, confirming that it was amorphous.

Production Example 7 Aqueous disodium phosphate @IIK 5 Chronic magnesium chloride solution was added dropwise to a My/P molar ratio of t5 (7
At this time, 5N sodium hydroxide was added at once to prevent the pH from becoming 9 or less.

The following steps were followed by reaction, filtering, washing, and drying under the same conditions as in Production Example 6. ,, This was xmm-folded magnesium phosphate 22-hydrate salt. 100 f of Kono22 water salt was spread thinly and dehydrated in an internal heating dryer at 100°C for 30 minutes. The weight of the dehydrated product was 55 tons.

As a result of the analysis, the composition was found to be hexahydrate salt. Also, is this one manufactured by Fi? Similar to No. 116, KXIIvA analysis showed that it was amorphous.

Production Example 8 (Comparative Production Example) 2016 phosphoric acid solution was added to 20% magnesium hydroxide slurry so that the Mf/p molar ratio was 15. At this time, 5N sodium hydroxide S was added to prevent the pH from becoming 9 or less. * was added at the same time.

Note that the reaction temperature was 1jso°C and the reaction time was 5 hours.

The crystals obtained in this way are extremely fine with an average grain size of about 11 to 5 μm, so it takes a long time to process them.

After washing the crystals, they were dried at 80°C. X of this product
The line (b) folding pattern showed stripes in Figure 4 (2) f, and it was confirmed that it was a magnesium phosphate octahydrate crystal.

Production Example 9 (Comparative Production Example) Magnesium phosphate didodechydrate 100F obtained in the same manner as Production Example 6 was spread thinly on a pad and dried in an internal heating dryer (80°C).
It was dehydrated at ℃ for 40 minutes. Weight of dehydrated product of this product F1
The amount of combined water was 11fiff and the composition was 10 decahydrate. This material is confirmed to be amorphous by xlll#J fold II 1. ,Ta.

Examples and ratios I 2 Examples Preparation fl J 1.2.5.4.5 [7 with dicalcium phosphate dihydrate and Preparation Example 6.7.8, ? Add and mix a certain amount of magnesium nonaphosphate or the reagent birophosphate (2), crush it with a crusher, pass 350°, take a round sample, and conduct a physical property test and stability test. is shown in @19.

In addition, the physical property test was as follows.

(a) Average particle size: Based on 9 air permeation method.

(b) Bulk specific gravity: Constant value after 50 tappings using a line ironworks Shingeki powder tester.

(c) Dispersibility: Make a paste of the sample and 80% glycerin, and adjust using a JI8-5101 grind meter.

(d) Condition of kneading: Condition when sample and 80% glycerin are squeezed.

(ts) Oil absorption: The amount of glycerin when 50 tons of sample is kneaded with 80-glycerin to reach a constant viscosity. .

rf) Polishing power... Sample in 30glycerin molten case:
Weight loss when a U piece is polished for a certain period of time using a toothbrush of constant hardness in a suspension.

In the stability test, samples 50F and 80% glycerin 20F were kneaded together in test tubes, and the conditions were observed and evaluated after being allowed to stand at various temperatures for various periods of time. The evaluation display symbols are as follows.

O: The viscosity of the specimen before and after the test does not change at all.Compared to before the O test, the sample is slightly solidified and viscosity is observed.Δ: Solidified and has almost no fluidity×Cause: Solidified and fluid There is no

[Brief explanation of drawings]

1.2.5 WJF is a microscopic photograph of dicalcium acid dihydrate. Figure #11 is the one of the present invention, and Figures 2 and s are comparative examples. 4 are X@ diffraction patterns of magnesium phosphate of the present invention and for comparison, and (1) is that of the present invention. Agents 1) Akira Agent Ryo Yabuhara - O 1 Figure 1 Yotomi; +2 Figure 101 μm Fang 4 Figure 2θ (0)

Claims (1)

[Scope of Claims] t(A) dicalcium phosphate dihydrate consisting of a mixture of dicalcium phosphate dihydrate having plate-like to columnar crystals and distone phosphate R dihydrate having flat crystals; B) T in a stratification in which the amount of bound water is less than octahydrate
A stabilized secondary salt of dicalcium phosphate for toothpaste, which is made by crushing a mixture with magnesium and is amorphous. Z Reaction temperature of alkali metal phosphate and calcium is 14 [
IJ! J Lower K Te, J1 11th stage to react at pHvrL5-15, and 11N2 stage to pH 35-50, obtained by dicalcium phosphate dihydrate consisting of a mixture of polymorphic to polymorphic crystals and monocrystalline crystals. A stabilized sulfate salt R2 hydrate for tooth brushing is used.