JPH06199622A - Powder for curable material - Google Patents

Abstract

PURPOSE:To provide a curable material powder substantially not deteriorated even when being contact in with moisture in air for a long period, stable in its quality even when used for cement, and excellent in storage stability by mixing calcium phosphate with a polysaccharide and/or a sugar alcohol. CONSTITUTION:The curable material powder is incorporated with 0.1-30wt.%. of a polysaccharide and/or a sugar alcohol to a base material containing self- curable calcium phosphate powder (especially alpha-type tricalcium phosphate) and/or a slightly soluble fluoride (especially an alkaline earth metal fluoride). The curable material powder may especially contain one or more of barium sulfate, basic bismuth carbonate, and iodoform as a X-ray contract medium. Since the polysaccharide and the sugar alcohol are easily dissolved in water and are easily mixed with other power, and the powdery polysaccharide and the powdery sugar alcohol are preferable in order to improve their miscibility with other powder. Even when the powder is mixed with a X-ray contrast medium, the powder can be stored for a long period. Even when used as a cement, the handleability of the curable composition is good.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a powder material for a curable material. More specifically, the present invention relates to a powder material having excellent storage stability, which is used for a curable material obtained by mixing calcium phosphate powder with a polysaccharide and / or sugar alcohol.

[0002]

2. Description of the Related Art Self-hardening calcium phosphate refers to one that hardens by reacting with water. Of these, those that produce hydroxyapatite (hereinafter, abbreviated as HAP) after being hardened particularly have recently been used as medical cements for teeth, bone filling agents, etc. because HAP approximates to the main components of teeth and bones in vivo. Attention has been paid. The self-hardening calcium phosphate is kneaded with a liquid agent such as water to obtain cement, and in order to improve the operability at that time, it is used by crushing with a ball mill or the like. Since self-curing calcium phosphate is active in water as it is hardened by reacting with water, it may change over time due to adsorption of water in the air. For example, α-type tricalcium phosphate, which is attracting attention as a self-hardening calcium phosphate, gradually stores a part of α-type tricalcium phosphate into massive HAP when stored under high temperature and high humidity. Therefore, it takes time to knead with the liquid agent to form a paste at the time of use, and it becomes difficult to perform the operation even if it is inserted, filled or poured into the application site. In addition, even when kneading, there were cases in which there was a phenomenon in which variations did not disappear and a good paste was not formed.

As described above, when cement is prepared by kneading with a liquid agent, there are problems that the curing time varies, the kneading property deteriorates, and the quality (operability) is not stable. there were. Therefore, in order to prevent the time-dependent change of the self-curing calcium phosphate, the packaging may be filled in a water-impermeable glass container or the like, but even in that case,
Once opened, the self-curing calcium phosphate powder adsorbs moisture in the air after each use and causes a change over time, which gradually deteriorates the operability and thus has a problem in storage stability. The present inventors have also confirmed that the addition of basic bismuth carbonate, which is an X-ray contrast agent, facilitates the aging change of self-curing calcium phosphate. Therefore, it has been strongly desired to develop a powder material for a curable material, which does not easily deteriorate even if it is contacted with moisture in the air for a long time, has stable quality when used as cement, and has excellent storage stability.

[0004]

In view of the above situation, the present inventors have diligently studied calcium phosphate having excellent storage stability, which is unlikely to deteriorate due to adsorption of moisture in the air over time, and as a result, polysaccharides and It was found that a powder material for a curable material having excellent storage stability and stable quality when used as a cement can be obtained by mixing sugar alcohol with a specific ratio, and thus has completed the present invention. is there. That is, the present invention provides a powder material for a curable material, which comprises a self-curing calcium phosphate powder as a base material and contains 0.1 to 30% by weight of a polysaccharide and / or a sugar alcohol. is there.

The present invention will be described in more detail below. The self-curing calcium phosphate referred to in the present invention is one that exhibits curability by hydration when kneaded with water or water containing a curing accelerator such as an acid, and is exemplified by α-type tricalcium phosphate and phosphorus. Self-curing calcium phosphate such as tetracalcium acid or a mixture of α-type tricalcium phosphate and tetracalcium phosphate or non-self-curing calcium phosphate such as octacalcium phosphate, β-type tricalcium phosphate and calcium hydrogen phosphate Is a mixture of.
The atomic ratio of calcium and phosphorus is Ca / P = 1.3 to 2.0
Is preferable, and more preferably Ca / P = 1.4-
The range is 1.8. If the composition has a Ca / P ratio outside this range, the difference between the theoretical composition of HAP and the Ca / P ratio is too large. Therefore, even if calcium phosphate is kneaded with water containing a curing accelerator such as an acid, it does not harden. It is difficult to convert to a HAP structure, and it is difficult to obtain a good cured product. Although the production method thereof is not particularly limited, for example, in the case of α-type tricalcium phosphate, γ-type calcium pyrophosphate obtained by heating dicalcium phosphate at about 550 ° C. for about 2 hours is mixed with calcium carbonate. It is particularly preferable to use one that is calcined and pulverized at about 1200 ° C., and one having a particle size of 100 μm or less, preferably 20 μm or less can be suitably used.

According to the present invention, the calcium phosphate powder is mixed with a polysaccharide and / or a sugar alcohol in an amount of 0.1 to 30% by weight (hereinafter,% by weight is represented by% unless otherwise specified), preferably 1 to 10% by curing. It is a powder material for conductive materials. If the mixing amount of the polysaccharide and / or sugar alcohol is too small, the storage stability of the powder will not be improved, and if it is too large, the storage stability will be improved, but when the solvent is mixed to form a paste, the viscosity is high. It is not preferable because it becomes too much and the fluidity is lowered and the operability and workability are deteriorated in use. Specific examples of the polysaccharides used in the present invention include celluloses such as sodium carboxymethyl cellulose, glycogen, pentosan,
Hexosan, starch and the like can be mentioned, and specific examples of the sugar alcohol include sorbit, mannitol, xylit and the like.

The calcium phosphate composition of the present invention may further contain a poorly soluble fluoride, if necessary. It has been confirmed that when a sparingly soluble fluoride is added to calcium phosphate, it becomes fluorapatite when it is used as a cement. This fluorapatite is known as a particularly stable form among apatites, and it can be easily understood that this cement exhibits excellent stability in the living body or the oral cavity. The amount of sparingly soluble fluoride is Ca / F (gram atom ratio) =
It is at least 4.2 or more, and in practice, about Ca / F = 60 or less is preferable because the curing time is within several hours.

Specific examples of the poorly soluble fluoride include alkaline earth metal fluorides such as calcium fluoride, magnesium fluoride, strontium fluoride and barium fluoride, lithium fluoride, chromium fluoride, lead fluoride, Metal fluorides such as nickel fluoride, iron fluoride, aluminum fluoride, sodium silicofluoride, potassium silicofluoride,
Examples thereof include calcium silicofluoride and barium silicofluoride, which may be used alone or as a mixture of two or more. Further, the calcium phosphate composition of the present invention may further contain an X-ray contrast agent, if desired. As the X-ray contrast agent, one or more kinds can be selected from the group consisting of barium sulfate, basic barium carbonate and iodoform. The addition amount of the X-ray contrast agent is not particularly limited, but it is preferably 0 to 30% in the powder material.

The calcium phosphate powder and the polysaccharide and / or sugar alcohol are preferably mixed uniformly.
The method of mixing includes wet mixing and dry mixing. The wet mixing is a method in which the polysaccharide and / or sugar alcohol is dissolved in water and then mixed with the calcium phosphate powder, but dry mixing is preferable because it is considered that the calcium phosphate powder is contacted with water to be deteriorated. As for the dry mixing, there is no particular limitation on the mixing method, mixing time, etc. as long as uniform mixing is possible. When the calcium phosphate-based composition contains a poorly soluble fluoride and / or an X-ray contrast agent, either wet mixing or dry mixing may be used. As the wet mixing, a method of mixing a sparingly soluble fluoride and / or an X-ray contrast agent and a polysaccharide and / or sugar alcohol dissolved in water, drying the mixture, and then mixing with calcium phosphate powder, etc. are particularly preferable. There is no limitation on mixing time. As for the dry mixing, there are no particular restrictions on the mixing method, mixing time, etc., as long as uniform mixing is possible. It should be noted that polysaccharides and / or sugar alcohols have good workability when they are easily dissolved in water in wet mixing, and powdery rather than lumps are easy to uniformly mix with calcium phosphate powder in dry mixing. The shape is preferable. The calcium phosphate-based composition of the present invention is unlikely to be deteriorated even when it is contacted with moisture in the air for a long period of time, the quality is stable when used as cement, and a powder material for a curable material having excellent storage stability can be easily obtained. It is possible.

[0010]

The present invention will be described in more detail with reference to the following examples. Example 1 20 g of α-type tricalcium phosphate (α-TCP) powder and 2 g of sodium carboxymethyl cellulose were dry-mixed for 10 minutes using a mixer. The calcium phosphate-based composition produced in this manner was used at a temperature of 60 ° C. and a relative humidity of 70.
%, An acceleration test was performed for 2 weeks in a thermo-hygrostat. After the acceleration test, the hydration rate of α-TCP was measured. The hydration rate of α-TCP was measured by a powder X-ray diffractometer. TiO is added to the calcium phosphate-based composition before and after the hydration test.
₂ (rutile type) was added as an internal standard at 20%, and α-
The hydration rate of α-TCP was calculated by the following formula from the peak height of 30.8 °, which is the main peak of TCP, and the peak height of 27.5 °, which is the main peak of TiO ₂ (rutile type).

[0011]

[Equation 1]

According to JIS T 6604, 2 g of a powder agent composed of a calcium phosphate-based composition subjected to an accelerated test, 0.5 ml of a liquid agent composed of 0.75 mol of citric acid, 1.0 mol of potassium hydroxide and 0.63 mol of sodium acid fluoride were added. Comprehensive evaluation of operability was carried out from the kneading properties of cement when kneading in accordance with the above, and the filling properties into the crushing resistance formwork. As a result of the measurement, α-TC
The hydration ratio of P was low, and the miscibility of the cement and the filling property into the crushing resistance form were good. Example 2 The same conditions as in Example 1 were carried out except that sodium carboxymethyl cellulose was changed to mannite. As a result of the measurement, the hydration rate of α-TCP was low, and the miscibility of the cement and the filling property in the crushing resistance mold were good. Example 3 The same conditions as in Example 1 were carried out except that 20 g of α-TCP powder, 1 g of sodium carboxymethyl cellulose and 1 g of mannitol were dry-mixed for 10 minutes with a mixer. As a result of the measurement, the hydration rate of α-TCP was low, and the miscibility of the cement and the filling property in the crushing resistance mold were good. Example 4 The same conditions as in Example 1 were carried out except that 20 g of α-TCP powder, 2 g of sodium carboxymethyl cellulose, and 0.05 g of calcium fluoride which was a poorly soluble fluoride were dry-mixed for 10 minutes with a mixer. Measurement result, α-T
The hydration ratio of CP was low, and the miscibility of the cement and the filling property into the crushing resistance form were good.

Example 5 100 g of water in which 2 g of sodium carboxymethyl cellulose was dissolved was gradually added to 0.5 g of calcium fluoride which is a poorly soluble fluoride and 2 g of basic bismuth carbonate which is an X-ray contrast agent, which are heated and stirred at 90 ° C. The same procedure as in Example 1 was carried out, except that 20 g of α-TCP powder was mixed with 10 g of the mixture in a mixer for 10 minutes. As a result of the measurement,
The hydration rate of α-TCP was low, and the miscibility of the cement and the filling property in the crushing resistance form were good. Example 6 2 g of basic bismuth carbonate which is an X-ray contrast agent heated and stirred at 90 ° C. was gradually sprayed with 100 cc of water in which 2 g of sodium carboxymethyl cellulose was dissolved, mixed and dried, and then 20 g of α-TCP powder and a mixer. The same conditions as in Example 1 were used except that the mixing was performed for 10 minutes. As a result of the measurement,
The hydration rate of α-TCP was low, and the miscibility of the cement and the filling property in the crushing resistance form were good.

Comparative Example 1 0.01 g of sodium carboxymethyl cellulose was added.
The same conditions as in Example 1 were used except that the procedure was changed to. As a result of the measurement, the hydration rate of α-TCP was high, and further, the miscibility of the cement and the filling property in the crushing force frame were poor. Comparative Example 2 20 g of α-TCP powder, 0.5 g of calcium fluoride which is a sparingly soluble fluoride, 2 g of basic bismuth carbonate which is an X-ray contrast agent, and sodium carboxymethylcellulose of 0.2 g.
The same conditions as in Example 1 were used except that 01 g was mixed for 10 minutes using a mixer. As a result of the measurement, the hydration rate of α-TCP was high, and further, the miscibility of the cement and the filling property in the crushing resistance form were poor. Comparative Example 3 The procedure of Example 1 was repeated, except that the amount of sodium carboxymethyl cellulose was changed to 10 g. As a result of the measurement, the hydration rate of α-TCP was low, but the viscosity of the cement was too high and the fluidity decreased, and the miscibility of the cement and the filling property into the crushing force formwork were poor. .

[0015]

[Table 1]

[0016]

According to the present invention, it is possible to suppress deterioration of the calcium phosphate-based composition during storage, which has not been achieved by the prior art. That is, in Comparative Examples that are outside the scope of the present invention, it was difficult to prevent alteration of the self-curable material during storage, and the operability was poor when it was used as cement. On the other hand, the examples within the scope of the present invention are not deteriorated by moisture and are good without impairing operability. Further, even if an X-ray contrast agent, which has conventionally been accelerated in deterioration due to water, is mixed, it can be stored for a long period of time and the operability when used as a cement was good.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akio Yoshikawa 7-1, 1-1 Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Yoshihito Ochiai 3-3 Motofujisawa, Fujisawa-shi -7 (72) Inventor Koichi Saito 457 Yamanishi, Ninomiya-cho, Naka-gun, Kanagawa Lion Ninomiya Dormitory (72) Inventor Fumio Osato 457 Yamanishi, Ninomiya-cho, Naka-gun Kanagawa Prefecture Ninomiya Dormitory, Ltd.

Claims (5)

[Claims] 1. A powder material for a curable material, which comprises a self-curing calcium phosphate powder as a base material and contains 0.1 to 30% by weight of a polysaccharide and / or a sugar alcohol. 2. A curable material comprising a base material containing self-curing calcium phosphate powder and a sparingly soluble fluoride containing 0.1 to 30% by weight of a polysaccharide and / or a sugar alcohol. Powder material. 3. The powder material for curable material according to claim 1, wherein the calcium phosphate powder is α-type tricalcium phosphate. 4. The powder material for a curable material according to claim 2, wherein the hardly soluble fluoride is an alkaline earth metal. 5. The powder material for curable material according to claim 1, 2 or 3, which contains one or more compounds selected from the group consisting of barium sulfate, basic bismuth carbonate and iodoform as an X-ray contrast agent. The powder material for the curable material described.