JPH09315924A - Production of curing agent for impression material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curing agent for an impression material giving a constant curing time even after the storage over a long period by applying a specific treatment to a mixture of magnesium oxide and a surfactant constituting the curing agent. SOLUTION: This curing agent is composed of calcium sulfate and/or lead silicate, a surfactant, magnesium oxide and a scarcely watersoluble liquid compound. In this composition. a mixture of at least magnesium oxide and the surfactant is heated at 40-150 deg.C, more preferably 50-80 deg.C. The necessary heating time depends upon the heating temperature and is shorter at a higher heating temperature. It is preferably selected within the range of 1hr to several days. The surfactant is preferably a nonionic surfactant such as polyoxyethylene alkyl ether and its amount is 0.1-10 pts.wt., preferably about 0.5-5 pts.wt. based on 100 pts.wt. of calcium sulfate and/or lead silicate. The amount of magnesium oxide is preferably about 5-50 pts.wt. based on 100 pts.wt. of calcium sulfate and/or lead silicate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hardening agent for hardening an impression material used for shaping a tooth or the like.

[0002]

2. Description of the Related Art Alginate impression materials are generally used for molding a tooth for repairing the tooth. The alginate impression material utilizes the fact that a gel-like cured product is obtained by kneading the base material, alginate, and the curing agent, calcium sulfate, with water.

Alginate impression materials are classified into two types, powder type and paste type, depending on the packaging condition. The powder type is a type in which a base material and a curing agent are mixed in a powder state and kneaded with water at the time of use. On the other hand, the paste type is a type in which the base and the curing agent are separately kneaded with water in advance to form a paste, and the base paste and the curing agent paste are kneaded when used.

As a curing agent for such a paste type alginate impression material, there has already been proposed a composition containing calcium sulfate as a main component and a poorly water-soluble liquid admixture and a surfactant added thereto (Japanese Patent Application Laid-Open No. 2000-242242). 62-26520
Japanese Patent Laid-Open No. 4-235109). Further, it is also known to add magnesium oxide, phosphate, and potassium fluorotitanate for the purpose of adjusting the curing time (JP-A-4-235109).

[0005]

However, when a curing agent containing magnesium oxide is used as a curing agent for an alginate impression material, if a curing agent is mixed with a base immediately after being adjusted, a certain curing time is exhibited. Studies by the present inventors have revealed that there is a problem that the curing time is delayed when mixed with a base after being stored for a long period of time. If the curing time changes depending on the storage time of the curing agent, it is necessary to change the waiting time until curing in the impression molding.
There is an inconvenience that you cannot always operate under certain conditions. Therefore, there is a demand for a curing agent that does not delay the curing time even when stored for a long period of time and keeps the curing time constant.

[0006]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to solve the above problems, a mixture of magnesium oxide, which is a constituent of the curing agent, and a surfactant was added at 40 ° C.
It was found that a good curing agent that overcomes the above problems can be obtained by heating to ~ 150 ° C, and has completed the present invention.

That is, the present invention provides at least magnesium oxide in a method for producing a curing agent for impression materials containing calcium sulfate and / or lead silicate, a surfactant, magnesium oxide, and a poorly water-soluble liquid compound as main components. And a surfactant are heated to 40 ° C. to 150 ° C., which is a method for producing a hardened material for impression materials.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the calcium sulfate and / or lead silicate used in the present invention, known ones used for conventional impression materials can be used without any limitation. Specific examples of particularly preferably used ones include calcium sulfate dihydrate, calcium sulfate hemihydrate, calcium sulfate anhydrous, etc., alone or in combination. Further, lead silicate may be used alone or in combination with calcium sulfate.

As the surfactant used in the present invention, known surfactants can be used without any limitation. Anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants can be used. Any of the activators can be used. Specific examples of the surfactant include anionic surfactants such as alkyl sulfonates, alkylbenzene sulfonates, and alkyl ether carboxylates. As the cationic surfactant, an alkylamine salt,
Examples of the quaternary ammonium salt, and examples of the amphoteric surfactant include an aminocarboxylic acid salt. Further, as the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene-polyoxypropylene block polymer, polyoxyethylene glycerin aliphatic ester, sucrose ester, polyoxydiethyleneamine ,
Examples thereof include block polymers of polysiloxanes and polyoxyethylenes.

In the present invention, nonionic surfactants, especially polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylenes, are used as the surfactant because of the great effect of keeping the curing time constant. -Nonionic surfactants having a polyoxyalkylene chain, such as polyoxypropylene block polymers, polyoxyethylene glycerin aliphatic esters, polyoxydiethylene amines, block polymers of polysiloxanes and polyoxyethylenes, are preferably used. can do.

The amount of the above-mentioned surfactant used is not particularly limited, but in order to uniformly mix the powder component constituting the curing agent and the poorly water-soluble liquid compound, and to knead the curing agent and the base material. In order to speed up the mixing of the curing agent and the base material, the content is preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 5 parts by weight, relative to 100 parts by weight of calcium sulfate and / or lead silicate. It is preferably part by weight.

Magnesium oxide used in the present invention is
This has the effect of shortening the curing time and further reducing the difference between the curing start time and the curing end time. The amount of magnesium oxide used is not particularly limited, but calcium sulfate and / or lead silicate 100 may be used in order to adjust the curing grace time from kneading to curing to an appropriate value to improve the moldability.
It is preferably 5 to 50 parts by weight based on parts by weight.

Magnesium oxide includes light magnesia,
There are types such as heavy magnesia and magnesia clinker, but any magnesium oxide can be used.
Particularly, as the magnesium oxide effective for adjusting the curing time, a light magnesia having a specific surface area of 100 to 200 m ² / g and an average particle diameter of 1 to 10 μm and high reactivity is preferably used. To be

In the present invention, the poorly water-soluble liquid compound is
An organic solvent, which is a solvent for making the curing agent into a paste and has poor compatibility with water, is used. Especially water 100 at 20 ℃
An organic solvent having a solubility with respect to g of 5 g or less can be preferably used. Examples of the poorly water-soluble liquid compound include hydrocarbons, aliphatic alcohols, aromatic alcohols, fatty acids, salts or esters thereof, hydrophobic polymers and the like, and hydrocarbons are particularly preferably used. The poorly water-soluble liquid compound preferably has 6 or more carbon atoms for the purpose of suppressing volatilization.

As the above-mentioned hydrocarbon, both chain type and cyclic type can be used. Specific examples of hydrocarbons that can be preferably used in the present invention are as follows. For example, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, kerosene, aliphatic chain hydrocarbons such as 2,7-dimethyloctane, 1-octene, cycloheptane, cyclononane, liquid paraffin. And other aliphatic cyclic hydrocarbons.

Examples of the aliphatic alcohol include saturated aliphatic alcohols such as 1-hexanol and 1-octanol, and unsaturated aliphatic alcohols such as citroneol and oleyl alcohol.

Examples of aromatic alcohols include benzyl alcohol and metacresol.

Examples of fatty acids include saturated fatty acids such as hexanoic acid and octanoic acid, and unsaturated fatty acids such as oleic acid and linoleic acid. Examples of fatty acid esters include ethyl octanoate, dibutyl phthalate, oleic acid glyceride, vegetable oils such as olive oil and sesame oil, and animal oils such as liver oil and whale oil.

Examples of the hydrophobic polymer include polysiloxane and the like. Specific examples thereof include polydimethyl siloxane, polymethyl phenyl siloxane, polymethyl hydrogen siloxane, and polyphenyl hydrogen siloxane.

The amount of the above-mentioned poorly water-soluble liquid compound used is calcium sulfate and / or lead silicate in order to obtain a uniform paste, have good fluidity, and maintain good miscibility with the base. It is preferably 10 to 200 parts by weight, more preferably 30 to 150 parts by weight, relative to 100 parts by weight.

In the present invention, among the components of the curing agent for impression materials, the greatest feature is that at least a mixture of magnesium oxide and a surfactant is heated at a temperature of 40 ° C to 150 ° C. The heating temperature may be 40 ° C to 150 ° C, but a more preferable temperature range is 50 ° C to 80 ° C.
When the heating temperature is lower than 40 ° C., the curing time of the impression material is greatly delayed due to long-term storage of the curing agent, and it cannot be put to practical use. Also, heating at a temperature above 150 ° C. is not preferable because the surfactant is easily decomposed.

The heating time differs depending on the heating temperature, but the higher the heating temperature, the shorter the heating time. The heating time is generally 1
It is preferable to select in the range of time to several days.

The following method can be exemplified as a specific method for adjusting the curing agent for impression materials of the present invention.
(1) Two components of magnesium oxide and a surfactant are mixed in a kneader at room temperature and heated at a temperature of 40 ° C. to 150 ° C., and then calcium sulfate and / or lead silicate, which is another component, and poorly water-soluble A method for producing a curing agent for an impression material by mixing with a liquid compound. (2) Magnesium oxide, a surfactant, calcium sulfate and / or the main constituents of the curing agent for impression materials
Alternatively, a method in which lead silicate and a poorly water-soluble liquid compound are mixed at room temperature and then heated to 40 ° C to 150 ° C. (3) Above (1)
And (2), a method of mixing two components of magnesium oxide and a surfactant, or a main component of a curing agent for an impression material in addition to these two components at 40 ° C to 150 ° C.

Since the hardener for impression materials produced by the present invention easily absorbs moisture, it is preferable to store it in a glass container, a metal container, or an aluminum pack in which aluminum is laminated with a resin film so that water cannot easily pass through.

In addition to the above components, potassium fluorotitanate, phosphate, zinc oxide, etc. may be added to adjust the curing time. In addition, an inert inorganic powder such as silica, titania, or alumina may be added as a filler. Furthermore, after mixing powders such as calcium sulfate, lead silicate, magnesium oxide, potassium fluorotitanate, and inert inorganic powders with a poorly water-soluble liquid admixture, particles of these powders settle. To prevent this, ultrafine particles of silica, titania, or zirconia having a primary particle diameter of 0.1 μm may be added. These ultrafine particles may be used either on the surface of which the hydrophobic treatment is performed or on the surface of which are not subjected to the hydrophobic treatment, or may be used as a mixture of both. Especially,
In order to enhance the effect of dispersing, it is preferable to use hydrophobic ultrafine particles. These ultrafine particles may be mixed with a surfactant and a poorly water-soluble liquid admixture at the same time as the above powders. In particular, in order to enhance the effect of preventing the settling of the particles of the powder in the curing agent for impression materials, after mixing the particles of the powder, the surfactant and the hardly water-soluble liquid admixture, these ultrafine particles are added,
Mixing is preferred.

As the mixing and kneading machine for producing the above-mentioned curing agent for impression materials, known kneading machines can be used without any limitation. Specifically, it has a horizontal or vertical axis such as a rotary container type mixing and kneading machine such as a ball mill, a ribbon mixer, a co-kneader, an internal mixer, a screw kneader, a Henschel mixer, a universal mixer, a Reedige mixer, and a butterfly mixer. A fixed container type mixing and kneading machine may be used. These mixing and kneading machines may be used alone or in combination. In particular, a method of previously mixing only the above powder with a Loedige mixer and then mixing with a hardly water-soluble liquid admixture with a butterfly mixer is preferable because a uniform curing agent can be produced in a short time.

[0027]

According to the method of the present invention, a curing agent for impression materials having a stable curing time for a long period of time can be obtained. Moreover, the change in the viscosity of the curing agent is stable for a long period of time. Therefore, since the curing time is constant at the time of taking an impression, it can be placed in the oral cavity and safely removed after a fixed time. Further, since the viscosity of the curing material is constant, it is possible to always mix and knead with the base material with the same kneadability, and it is possible to obtain an impression agent having a uniform and stable property. Therefore, a precise impression surface can be obtained.

[0028]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. The curing time and the storage stability shown in the following Examples and Comparative Examples were measured according to the following methods.

(1) Curing Time The pasty curing agent and the pasty base were thoroughly mixed on kneading paper. Then, the curing time is JIST-6505
It was measured according to.

(2) Storage stability After the curing agent was stored at 40 ° C. for a predetermined time, it was kneaded with the base material and the curing time was measured. Let the curing time before storage be the initial curing time, compare the difference with the curing time after storage,
The smaller the fluctuation, the higher the storage stability.

(3) Viscosity An appropriate amount of the curing agent was sampled, and the viscosity was measured under the condition of 23 ° C. using a high shear rheometer manufactured by Ishida Giken Co., Ltd.

Example 1 18 parts by weight of magnesium oxide (light magnesium oxide, average particle size 3.5 μm, specific surface area of 146 m ² / g) and 9 parts by weight of a surfactant (polyoxyethylene oleyl ether) in a container with stirring. Mix well. This mixture was stored in a constant temperature bath at 70 ° C. for 5 hours, and then 100 parts by weight of calcium sulfate (25 parts by weight of calcium sulfate dihydrate, 75 parts by weight of calcium sulfate anhydrous salt) and 17 parts by weight of granular silica were added to the mixture. , 50 parts by weight of liquid paraffin, 10 parts by weight of zinc oxide, 2 parts by weight of trisodium phosphate, 9 parts by weight of potassium fluorotitanate, and 5 parts by weight of ultrafine silica, and thoroughly mixed with a planetary mixer to form a paste. A curing agent of was prepared.

On the other hand, 3.6 parts by weight of potassium alginate,
A paste-like base (pH 7.4) consisting of 9 parts by weight of silica powder, 0.3 parts by weight of potassium hydroxide, 1.8 parts by weight of polyacrylic acid, and 100 parts by weight of water was prepared.

Next, when the initial curing time was measured using the above curing agent and base, it was 2 minutes and 38 seconds. Further, when the curing time was measured after the curing agent was stored at 40 ° C. for 90 days, it was 2 minutes and 42 seconds. It was found that the curing time hardly changed and the storage stability was high. Further, the viscosity was 710 poise in the initial stage and 730 poise after storage, which was almost unchanged. The curing agent was sealed and stored in an aluminum pack.

Example 2 18 parts by weight of the same magnesium oxide as in Example 1, 9 parts by weight of a surfactant (polyoxyethylene phenyl ether),
Liquid paraffin (50 parts by weight), calcium sulfate (100 parts by weight) and granular silica (17 parts by weight) were mixed at 80 ° C. for 3 hours to prepare a pasty curing agent. The curing time and viscosity were 2 minutes and 15 seconds at the beginning and 660 poises, and 2 minutes and 25 seconds and 670 poises after storage at 40 ° C. for 90 days, which showed almost no change. The curing agent was sealed and stored in a glass container.

Example 3 The components used in Example 2 were mixed at room temperature of 20 ° C. for 4 hours, and the paste-like curing agent was placed in a thermostatic chamber at 55 ° C. for 10 hours.
Heat treatment was performed over a period of days. The curing time and viscosity were 2 minutes and 1 second at 780 poise in the initial stage and 2 minutes and 15 seconds at 790 poise after being stored at 40 ° C. for 90 days, showing almost no change. The curing agent was sealed and stored in an aluminum pack.

Comparative Example 1 18 parts by weight of magnesium oxide of Example 1, 9 parts by weight of a surfactant (polyoxyethylene oleyl ether), 50 parts by weight of liquid paraffin, 100 parts by weight of calcium sulfate, 17 parts by weight of granular silica, zinc oxide. 10 parts by weight, 2 parts by weight of trisodium phosphate, 9 parts by weight of potassium fluorotitanate, and 5 parts by weight of ultrafine particle silica were added and sufficiently mixed with a planetary mixer to prepare a pasty curing agent.

Next, when the initial curing time was measured using the base material of Example 1, it was 1 minute and 0 seconds. Furthermore, when the curing time was measured after the curing agent was stored at 40 ° C. for 21 days, it was 2 minutes and 10 seconds. The cure time was significantly delayed. The initial viscosity was 650 poise, but it was 9 after storage.
It had changed to 20 poise.

Example 4 18 parts by weight of magnesium oxide (light magnesium oxide, average particle size 4.1 μm, specific surface area of 110 m ² / g), 9 parts by weight of surfactant (polyoxyethylene oleyl ether), 100 parts by weight of calcium sulfate (Calcium sulfate 2
25 parts by weight of water salt, 75 parts by weight of anhydrous calcium sulfate),
Granulated silica (17 parts by weight), liquid paraffin (50 parts by weight), zinc oxide (10 parts by weight), trisodium phosphate (2 parts by weight), potassium fluorotitanate (9 parts by weight), and ultrafine silica (5 parts by weight) were added, and a butterfly mixer was operated at 75 ° C. Mix for 8 hours,
A pasty curing agent was prepared.

Next, when the initial curing time was measured using the base material of Example 1, it was 2 minutes and 55 seconds. further,
When the curing time was measured after the curing agent was stored at 40 ° C. for 90 days, the curing time was 3 minutes 03 seconds, and there was almost no change. The viscosity was 760 poise at the beginning and 780 poise after storage.

Claims (1)

[Claims] 1. A method for producing a curing agent for an impression material, which comprises calcium sulfate and / or lead silicate, a surfactant, magnesium oxide, and a poorly water-soluble liquid compound as main constituents.
A method for producing a curing agent for an impression material, which comprises heating a mixture of at least magnesium oxide and a surfactant to 40 ° C to 150 ° C.