JP3499101B2 - Impression material - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impression material used for tooth and other mold taking. In particular, it relates to an alginate impression material excellent in dust prevention.

2. Description of the Related Art Impression materials containing alginate and a divalent metal salt such as calcium sulfate as a main component are called alginate impression materials or alginate impression materials. Is used for.
The alginate impression material has features such as good impression accuracy, capable of reproducing a fine portion, and easy impression operation, and is most often used as a dental impression material. The alginate impression material is a powdery mixture of all components such as alginate, divalent metal salt such as calcium sulfate and filler, and is kneaded with water when taking an impression at a dental clinic, Used as a paste. In this alginate impression material, when the impression material is kneaded with water, the carboxyl group of alginic acid is crosslinked by the divalent metal ion and gelled to give a cured product having elasticity. The hardened body of this impression material is a negative type, and plaster is poured into this, the gypsum is hardened, and then the plaster is removed from the hardened body of the impression material to prepare a model. By the way, since the alginate impression material is in the form of powder, when it is kneaded with water, the powder scatters into the air, polluting the air and deteriorating the working environment. In order to prevent the scattering of the powder, JP-A-57-501426 discloses a method of coating powder particles of an alginate impression material with a coating agent that wets water easily and rapidly. In this method, natural polymer dispersants as coating agents, cellulose esters or cellulose ethers, synthetic nonionic polymer surfactants, block copolymers of polysiloxanes and polyethylene glycols, polyols,
Alkanolamines, glycerol esters and the like are used.

By the way, it is known to add fine zinc oxide as a divalent metal salt to the impression material in order to harden the surface of the plaster model and increase the elastic strain. There is. However, if this fine zinc oxide is added, the powder tends to be more easily scattered. Therefore, an attempt was made to prevent the generation of dust by mixing the above coating agent. However, in order to prevent the generation of dust with the above-mentioned coating agent, a relatively large amount of coating agent must be used, which causes a large permanent set of the cured product, lowers the impression accuracy, and further long-term storage. It was later found that the gelation time tends to be delayed. Therefore, an object of the present invention is to provide an alginate impression material that is less likely to generate dust and has a small permanent set.

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that by using zinc oxide having a specific average particle size, there is little dust and a small permanent set alginate. I succeeded in obtaining an impression material and completed the present invention. That is, the present invention is an impression material mainly composed of 100 parts by weight of alginate, 5 to 500 parts by weight of calcium sulfate and / or lead silicate, and 1 to 20 parts by weight of zinc oxide, and the average particle diameter of zinc oxide is 0. Two
The impression material is characterized in that it is ˜2 μm.

BEST MODE FOR CARRYING OUT THE INVENTION The alginate used in the present invention is
Known materials used for impression materials can be used without any limitation. As a specific example, sodium alginate,
Examples thereof include potassium alginate and the like. These alginates are generally extracted from natural seaweed and neutralized. 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 suitable ones include calcium sulfate dihydrate, calcium sulfate hemihydrate, calcium sulfate anhydrous and the like. Further, lead silicate can be used in combination with calcium sulfate or alone. The compounding amount of calcium sulfate and / or lead silicate is 5 to 500 with respect to 100 parts by weight of alginate.
It is necessary to be a ratio of parts by weight, preferably 50 to 20.
The ratio is 0 part by weight. When the content of calcium sulfate and / or lead silicate is less than 5 parts by weight, the cross-linking of alginate is insufficient and gelation does not occur, and when it exceeds 500 parts by weight, a cured product having appropriate elasticity is obtained. Absent. In the present invention,
The greatest feature is to use zinc oxide having an average particle diameter of 0.2 to 2 μm. The use of zinc oxide having an average particle size smaller than 0.2 μm is not preferable because dust is likely to be generated, and conversely, when the average particle size is larger than 2 μm, the effect of hardening the surface of the gypsum model is lost, which is not preferable. The average particle size of zinc oxide is preferably in the range of 0.5 to 0.8 μm. As the zinc oxide used in the present invention, known ones can be used without any limitation as long as the average particle diameter is in the range of 0.2 to 2 μm. The content of zinc oxide is 1 to 20 parts by weight based on 100 parts by weight of alginate. If the content of zinc oxide is less than 1 part by weight, the effect of hardening the surface of the gypsum model is poor, and 20
If it exceeds the weight part, the generation of dust increases, which is not preferable. In the present invention, a wetting agent may be further added to the above impression material in order to facilitate the kneading of the impression material and water and suppress the generation of dust. The wetting agent need only be mixed with the impression material. The wetting agent is 0.0 in the total amount.
It is preferably in the range of 5 to 1% by weight, and more preferably in the range of 0.1 to 0.7% by weight. With such an amount of the wetting agent added, problems such as increase of permanent set of the cured product, deterioration of impression accuracy, and delay of gelation time after long-term storage do not occur. In the present invention, it is considered that the use amount of the wetting agent can be reduced because zinc oxide having a specific average particle size is used. As the wetting agent in the present invention, known wetting agents can be used without any limitation. Specific examples include nonionic polymer surfactants such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol and polyoxyethylene alkylene ether. In the alginate impression material of the present invention, as components other than the above, phosphates such as sodium pyrophosphate, trisodium phosphate or potassium salts thereof, oxalic acid or salts thereof, and fluorosilicate are used for adjusting the curing time. Sodium or its potassium salt, a clay mineral typified by diatomaceous earth, talc, silica, aluminum hydroxide, or the like, or an oxide or hydroxide of a metal or a metalloid may be added as a filler. The most preferred embodiment of the present invention is 100 parts by weight of potassium alginate, 50 to 200 parts by weight of calcium sulfate, and 5 to 5 parts of zinc oxide.
Wetting agent is added to 10 parts by weight in the total amount of 0.1 to 1% by weight.
The wetting agent is polyoxyethylene alkylene ether, and the average particle diameter of zinc oxide is 0.5 to
The impression material is 0.8 μm.

The impression material of the present invention has a small permanent set and a reduced generation of dust. Furthermore, the addition of a wetting agent can further reduce the generation of dust. If the impression material of the present invention is used, the work environment is good because the generation of dust is small, and there is an appropriately high elastic strain,
Since the permanent set is small, the impression accuracy is high, and the addition of zinc oxide has the advantage that the surface hardness of the plaster model is high.

EXAMPLES In order to explain the present invention more specifically,
The present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Examples 1 to 5 Powdery components were mixed in the composition shown in Table 1 to prepare a powdery impression material, 250 parts by weight of water was added to 100 parts by weight of the powder, and the mixture was kneaded with a rubber ball for 30 seconds. Mix, knead into paste, and set gel time, elastic strain, and permanent strain according to JIS
It was measured according to T-6505. The gypsum hardness was measured by the pencil hardness. As the plaster, "Stone 1" (trade name) manufactured by Tokuyama Corporation was used. Also, the diameter is 4
Impression materials (10 g) were placed in a cylindrical glass container of 0 mm × 100 mm in height, and the mixture was vigorously shaken for 5 seconds, and then the time until the dust settled was measured. This is shown in Table 1 as the degree of dust generation. The impression material of the present invention has a high elastic strain and a low permanent set as shown in Table 1, and has little dust generation.

[Table 1] Comparative Example 1 An impression material was prepared in the same manner as in Example 1 except that zinc oxide having an average particle diameter of 0.1 μm was used. The results are shown in Table 1. As a result of measuring the degree of elastic strain, permanent strain, and generation of dust, generation of dust was large, and it was not a preferable impression material.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-235109 (JP, A) JP-A-57-169411 (JP, A) JP-A-6-135813 (JP, A) JP-A-5- 58836 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41K 1/00 B41K 1/02

Claims (2)

(57) [Claims] 1. Alginate 100 parts by weight, calcium sulfate and / or lead silicate 5-500 parts by weight, zinc oxide 1-
20 parts by weight as a main component, used as a powder by kneading with water
In the alginate impression material, the average particle diameter of zinc oxide is 0.2 to 2 μm. 2. A humectant in an amount of 0.
05-1 claims, characterized in that contained in a weight percent range
The impression material according to item 1 .