JPH1072307A - Silicone composition for dental impression - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition suitable for fine impression, by adding each specific amount of a specific fine powdery silica, a nonionic surfactant and a methylphenyl polysiloxane. SOLUTION: This composition comprises an organopolysiloxane (100 pts.wt.) containing at least two aliphatic unsaturated hydrocarbons in one molecule, an organohydrogenpolysiloxane (0.1-30 pts.wt.) containing at least three hydrogens directly bonded to Si in one molecule, a silicone-soluble platinum compound (10-500ppm based on the total of the two polysiloxanes), an inorganic filler (10-500 pts.wt.), a fine powdery silica (5-50 pts.wt.) having 50-500m<2> /g BET specific surface area and the surface subjected to hydrophobic treatment, a nonionic surfactant (0.5-50 pts.wt.) and a methylphenyl polysiloxane (10-200 pts.wt.). The composition is large in elastic strain, small in permanent set, excellent in elasticity, does not cause sagging and tearing and excellent in wetting properties with water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding material (hereinafter referred to as an impression material) used for producing an intraoral model required for producing a dental prosthesis such as a crown, an inlay, and a denture in dentistry. And more particularly to a silicone composition for dental impression used for precision impression.

[0002]

2. Description of the Related Art Dental elastic impression materials made of agar, alginate, polysulfide rubber, polyether rubber, silicone rubber or the like are used. These elastic impression materials are suitable for taking impressions of teeth, dentition, jaw, mucous membrane, etc. in the oral cavity, which have a complicated shape with undercuts, because the deformation that occurs when the material is removed from the oral cavity is immediately recovered. ing.

[0003] Among these elastic impression materials, agar impression materials and alginate impression materials have clinically moderate elasticity, but on the other hand, they have large permanent deformation and have a large amount of moisture inside due to their structure. Because of the inclusion, evaporation of water from the taken impression causes a large dimensional change over time. Further, they have drawbacks such as low tear strength and easy tearing, so that they are mainly used for obtaining a general impression.

On the other hand, a synthetic rubber-based elastic impression material made of polysulfide rubber, polyether rubber, silicone rubber, or the like has advantages such as excellent reproducibility in detail, extremely small dimensional change with time, and resistance to tearing. Etc. For this reason, these synthetic rubber-based elastic impression materials are mainly used for precision impression acquisition. However, polysulfide-based impression materials made of polysulfide rubber have drawbacks such as strong unpleasant odor and slow curing. In addition, polyether rubber-based impression material is excellent in hydrophilicity, which is convenient for obtaining an impression of a state in which saliva exists as in the oral cavity,
There are drawbacks such as difficulty in removing the impression from the patient's mouth due to low rubber elasticity and hardness of the cured body. In addition, this polyether rubber has a disadvantage that it gives a patient discomfort when taking an impression because of its unique bitterness.Moreover, since it has a large permanent distortion, it may be deformed when removing the impression from the oral cavity. There is also a danger of getting

On the other hand, there are two types of impression materials made of silicone rubber: condensation polymerization type and addition polymerization type, depending on the curing method. Both types of room temperature curing type silicone rubber are used as dental silicone impression materials. It's being used. Above all, the addition-polymerized silicone impression material is most frequently used as a precision impression material because of its sharp curing, small permanent distortion and extremely small dimensional change. However, compared to the alginate impression material described above, the hardness after curing is high and not only causes pain to the patient when removing the impression from the patient's mouth, but also when preparing a plaster model using the acquired impression. When removing the plaster model from the impression, the plaster may be broken depending on the part. Further, compared to the above-mentioned polyether rubber-based impression material, the impression of details may be unclear due to inferior hydrophilicity due to saliva in the oral cavity. Furthermore, due to insufficient tear strength, when removing the impression from the patient's mouth, the impression material may be torn off depending on the impression site, resulting in an incomplete impression.

[0006] As described above, the impression materials currently used have their own advantages, but also have many disadvantages. Each impression material reproduces the state of the oral cavity in detail without causing any pain to the patient. However, it was incomplete as an impression material for producing a dental prosthesis with good fitting accuracy.

[0007]

However, among the above-mentioned impression materials, the addition-polymerized silicone impression material is most excellent in that it has a small dimensional change and permanent set and can obtain an accurate impression. Focusing on the excellent properties of addition-polymerized silicone, which are considered to be disadvantages: high hardness after curing, low elastic strain, poor wetting with water such as saliva, and insufficient tear strength. An object of the present invention is to develop a silicone composition for a dental impression having excellent performance for a precision impression by improving the above.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have found that an organopolysiloxane having at least two aliphatic unsaturated hydrocarbons in one molecule and a silicon in one molecule. An addition-polymerized silicone impression material composed of an organohydrogenpolysiloxane having at least three hydrogen atoms directly bonded to elemental atoms, a silicone-soluble platinum compound, and an inorganic filler has a specific fine powdered silica, By adding a specific amount of each of the ionic surfactant and methylphenylpolysiloxane, the elastic strain is large, the permanent strain is small, and the elasticity is high. The present invention was completed by successfully obtaining a silicone composition for dental impression having excellent wettability.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The silicone composition for dental impression according to the present invention comprises: A) 100 parts by weight of an organopolysiloxane having at least two aliphatic unsaturated hydrocarbons in one molecule; 0.1 to 30 parts by weight of organohydrogenpolysiloxane having at least three hydrogen atoms directly bonded to silicon atoms C) Silicone-soluble platinum compound (based on the total amount of A and B) 10 to 500 ppm D) Inorganic filler 10 E) fine powder silica having a BET specific surface area of 50 to 500 m ² / g and having a hydrophobic surface 5 to 50 parts by weight F) nonionic surfactant 0.5 to 50 parts by weight G) methylphenyl The polysiloxane is characterized by comprising 10 to 200 parts by weight of the above A to G.

In the silicone composition for dental impression according to the present invention comprising the components A to G, the component A is an organopolysiloxane having at least two aliphatic unsaturated hydrocarbons in one molecule. The organopolysiloxane is preferably linear and has both molecular chain terminals blocked with vinylsilyl groups.In this case, the terminal vinyl group may be plural or a vinyl group is contained in the chain. Is also good.

The organohydrogenpolysiloxane as the component B has at least three hydrogen atoms directly bonded to silicon atoms in its molecule, and functions as a crosslinking agent. If this organohydrogenpolysiloxane is less than 0.1 part by weight with respect to 100 parts by weight of component A, not only does the hardness of the cured product decrease, but also the curing speed becomes slow. It is not preferable because it becomes very brittle.

The silicone-soluble platinum compound serving as the component C acts as an addition reaction catalyst, and known chloroplatinic acid, alcohol-modified chloroplatinic acid, and a complex of chloroplatinic acid and an olefin can be used. Particularly preferably,
A vinylsiloxane complex of chloroplatinic acid is used. The amount of these additives is in the range of 10 to 500 ppm with respect to the total amount of the aforementioned component A and component B. If it is less than 10 ppm, the curing rate will be slow, and if there is a trace amount of a substance that inhibits the catalytic ability of the platinum compound, there will be problems such as slow curing. If it exceeds 500 ppm, the curing speed is too fast and expensive, resulting in an economic disadvantage. The silicone-soluble platinum compound such as chloroplatinic acid is preferably used by dissolving it in an alcohol-based, ketone-based, ether-based, hydrocarbon-based solvent, polysiloxane oil, or the like.

As the inorganic filler as the component D, quartz, cristobalite, diatomaceous earth, fused quartz, glass fiber, titanium dioxide, fumed silica and the like can be used. This inorganic filler may be used in an amount of 10 to 500 parts by weight based on 100 parts by weight of the component A. If the amount is less than 10 parts by weight, the cured product becomes brittle, and if it exceeds 500 parts by weight, the viscosity becomes too high. The resistance at the time of mixing becomes too large and is not suitable as a dental impression material.

The finely divided silica used as the component E is
The BET specific surface area is 50 to 500 m ² / g, and the surface is made hydrophobic. This hydrophobic finely divided silica is essentially methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, or the corresponding alkoxysilane, octamethylcyclotetrasiloxane, hexamethyldisiloxane, hexamethyldisilazane or the like. It can be obtained by heat-treating, for example, fumed silica as a hydrophilic silica with a surface treating agent such as a mixture or with these surface treating agents and water. All or most of the active silanol groups on the surface are (CH ₃ ) ₃ SiO _1/2 units, (CH ₃ ) ₂ SiO _2/2
Any known hydrophobic silica blocked with a hydrophobic group such as a unit or CH ₃ SiO _3/2 unit may be used. The hydrophobic fine powdered silica not only allows the fluidity of the kneaded impression material to have the desired fluidity characteristics without increasing the hardness of the cured product, but also allows mutual interaction with the F and G components described in detail below. The action also helps to improve the wettability with water. Further, since the tear strength is also improved, there is no possibility that the impression material which has entered the details when the impression is removed is torn. B of this hydrophobic fine powder silica
ET specific surface area must be 50 ~ 500m ² / g, BET
If the specific surface area is less than 50 m ² / g, the tear strength is not sufficient and the impression material is torn, and if it exceeds 500 m ² / g, the permanent set becomes too large, which is not suitable. The amount of the hydrophobic fine powder silica is 5 to 50 parts by weight per 100 parts by weight of the component A.
Parts by weight. If the amount is less than 5 parts by weight, the tear strength is insufficient, and bleeding of the polysiloxane oil tends to occur. If the amount is more than 50 parts by weight, the viscosity of the composition becomes too high, and the kneading operation becomes difficult.

As the nonionic surfactant as the component F, a nonionic surfactant in which a hydrophilic group is combined with an alkyl group, which is a lipophilic group, or hydrogen in an alkyl group, which is a lipophilic group, is used. A nonionic surfactant in which a hydrophilic group is combined with a fluorocarbon group substituted by fluorine is suitable.

Examples of the nonionic surfactant in which a hydrophilic group is combined with an alkyl group which is a lipophilic group include (1) polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, and polyoxyethylene alkyl phenyl ether. The addition mole number of ethylene oxide or propylene oxide is 1 to 30, and the alkyl group has 12 carbon atoms.
(22) sorbitan fatty acid esters, glycerin fatty acid esters, polyglycerin fatty acid esters, ethylene glycol fatty acid esters, polyethylene glycol fatty acid esters, propylene glycol fatty acid esters, pentaerythritol fatty acid esters, etc., and polyhydric alcohols. And a partial ester type of a fatty acid having 12 to 22 carbon atoms, (3) polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbite fatty acid ester, polyoxyethylene mannitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene Ethylene propylene glycol monofatty acid esters, ether ester type wherein the number of moles of ethylene oxide to be added is 1 to 30, and the fatty acid has 12 to 22 carbon atoms. (4) Polio Xyethylene castor oil / hardened castor oil, polyoxyethylene lanolin derivative, polyoxyethylene beeswax derivative, etc.
Examples thereof include those obtained by addition polymerization of ethylene oxide of 0, and those of an ester type with ethylene oxide.

Nonionic surfactants in which a hydrophilic group is combined with a fluorocarbon group in which hydrogen in an alkyl group, which is a lipophilic group, has been replaced by fluorine are represented by the following general formula: . _{RfO (CnH 2 nO) nH RfO} (CH 2 n) 1 O (CnH 2 nO) m RfBN (R ') (C 2 H 4 O) nH wherein Rf: fluorinated aliphatic having 1 to 20 carbon atoms A group or a fluorinated aromatic group, wherein the aliphatic group may be linear, branched or cyclic. B: 2 divalent linking group (e.g. -SO ₂ -, - CO-, etc.) R ': an alkyl group l a hydrogen atom or a C 1~20, m, n: 1~50 integer

The nonionic surfactant used in the present invention works effectively for the purpose of improving the wettability with water in the presence of the E component and the G component. The content of the nonionic surfactant must be in the range of 0.5 to 50 parts by weight with respect to the component A. If the amount is less than 0.5 part by weight, wettability with water is not sufficient, and if it exceeds 50 parts by weight, permanent set becomes large. In addition, even if these nonionic surfactants are used alone,
Use of a combination of more than one species is not a problem.

As the methylphenylpolysiloxane used as the G component, the following can be used.

[0020]

Embedded image

(Wherein, R is a methyl group or a phenyl group, m and n are integers and m ≧ 0 and n ≧ 0).

The G component, methylphenylpolysiloxane, has the effect of softening the cured product without changing the permanent strain and increasing the elastic strain. Further, the methylphenylpolysiloxane improves wettability with water in the presence of the E component and the F component. The content of this methylphenylpolysiloxane must be 10 to 200 parts by weight with respect to the component A, and if it is less than 10 parts by weight, sufficient elasticity cannot be obtained. It is not appropriate because bleeding occurs from

Further, in the present invention, various inorganic or organic colorants may be used as long as the properties of the composition are not lost. This includes, for example, coloring agents used in ordinary silicone impression materials such as red iron, titanium white, titanium yellow, and cobalt blue.

[0024]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A base paste and a catalyst paste having the following compositions were prepared. (Base paste) ・ 100 parts by weight of dimethylpolysiloxane blocked at both molecular chain terminals with dimethylvinylsiloxy group ・ 3 parts by weight of linear methylhydrogenpolysiloxane containing 40 mol% of methylhydrogensiloxane units ・ Poly Oxyethylene nonyl phenyl ether 10 parts by weight-Quartz 20 parts by weight (catalyst paste)-100 parts by weight dimethylpolysiloxane with both molecular chain ends blocked by dimethylvinylsiloxy group-1,3 divinyltetramethyldisiloxane-platinum complex 0.4 weight 3% by weight Silicone oil solution containing 3% by weight ・ BET specific surface area is 100m ² / g, and the surface is (CH ₃ ) ₃ SiO _1/2 single 10 parts by weight of hydrophobic fine powder silica ・ Methylphenyl 20 parts by weight of polysiloxane (phenyl group content: 5 mol%)

Equal amounts of the above-mentioned base paste and catalyst paste were collected, kneaded with a spatula for 30 seconds,
Elastic strain and permanent strain were measured according to the test method of ST 6513.
The larger the value of the elastic strain, the softer the cured product, and the smaller the value of the permanent strain, the sharper the curing and the less the deformation. In the tear test, after kneading the paste,
The test was carried out using a tear test specimen type A in the test method of SK 6301. Regarding the wettability with water, after the paste was kneaded similarly, a disc-shaped sample having a diameter of 30 mm and a thickness of 1 mm was prepared, and the contact angle with water was measured using a contact angle meter. Table 1 shows the results
It is summarized and shown. As shown in Table 1, the composition of Example 1 had a large elastic strain but a sufficiently small permanent set, was hardened sharply, and the cured product was soft and less deformed. It was also confirmed that the tear strength was high and that tearing was difficult. Furthermore, the contact angle with water was small and the wettability with water was excellent.

Example 2 A base paste and a catalyst paste having the following compositions were prepared. (Base paste) ・ 100 parts by weight of dimethylpolysiloxane blocked at both molecular chain terminals with dimethylvinylsiloxy group ・ 3 parts by weight of linear methylhydrogenpolysiloxane containing 40 mol% of methylhydrogensiloxane units ・ Poly 1 part by weight of oxyethylene lauryl ether ・ 800 parts by weight of quartz (catalyst paste) ・ 100 parts by weight of both ends of molecular chain blocked with dimethylvinylsiloxy group dimethylpolysiloxane ・ 1,3 divinyltetramethyldisiloxane-platinum complex 0.4 Silicone oil solution containing 3 parts by weight in weight-Hydrophobic fine powder silica with a BET specific surface area of 100 m ² / g and a surface blocked by about 20 parts by weight of (CH ₃ ) ₃ SiO _1/2 single-Methylphenyl poly Siloxane 400 parts by weight (phenyl group content: 25 mol%)-Quartz 200 parts by weight

An equal amount of the above-mentioned base paste and catalyst paste was collected, kneaded with a spatula for 30 seconds, and the same test as in Example 1 was performed. The results are summarized in Table 1. As shown in Table 1, the composition of Example 2 had a large elastic strain but a sufficiently small permanent set, was hardened sharply, and the cured product was soft and less deformed. It was also confirmed that the tear strength was high and that tearing was difficult. Furthermore, the contact angle with water was small and the wettability with water was excellent.

Example 3 A base paste and a catalyst paste having the following compositions were prepared. (Base paste) ・ 100 parts by weight of dimethylpolysiloxane blocked at both molecular chain terminals with dimethylvinylsiloxy group ・ 3 parts by weight of linear methylhydrogenpolysiloxane containing 40 mol% of methylhydrogensiloxane units ・ Poly 100 parts by weight of oxyethylene octyl phenyl ether • 100 parts by weight of cristobalite (catalyst paste) • 100 parts by weight of both ends of molecular chain blocked with dimethylvinylsiloxy group Dimethylpolysiloxane • 1,3 divinyltetramethyldisiloxane-platinum complex 0.4 weight 3% by weight Silicone oil solution containing 3% by weight ・ BET specific surface area is 100m ² / g and the surface is (CH ₃ ) ₃ SiO _1/2 Single 100 parts by weight of hydrophobic fine powder silica ・ Methylphenyl 150 parts by weight of polysiloxane (phenyl group content: 50 mol%)

An equal amount of the above-mentioned base paste and catalyst paste was collected, kneaded with a spatula for 30 seconds, and the same test as in Example 1 was performed. The results are summarized in Table 1. As shown in Table 1, the composition of Example 3 had a large elastic strain but a sufficiently small permanent set, was hardened sharply, and the cured product was soft and less deformed. It was also confirmed that the tear strength was high and that tearing was difficult. Furthermore, the contact angle with water was small and the wettability with water was excellent.

Comparative Example 1 A base paste and a catalyst paste having the following compositions, which are different from the present invention in having no E component, were prepared. (Base paste) ・ 100 parts by weight of dimethylpolysiloxane blocked at both molecular chain terminals with dimethylvinylsiloxy group ・ 3 parts by weight of linear methylhydrogenpolysiloxane containing 40 mol% of methylhydrogensiloxane units ・ Poly Oxyethylene nonyl phenyl ether 10 parts by weight-Quartz 50 parts by weight (catalyst paste)-100 parts by weight dimethylpolysiloxane with both molecular chain terminals blocked by dimethylvinylsiloxy group-1,3 divinyltetramethyldisiloxane-platinum complex 0.4 weight 3% by weight Silicone oil solution containing 3% by weight ・ Methylphenylpolysiloxane 100% by weight (phenyl group content: 25mol%) ・ Quartz 100% by weight

An equal amount of the above-mentioned base paste and catalyst paste was collected, kneaded with a spatula for 30 seconds, and the same test as in Example 1 was performed. The results are summarized in Table 1. As shown in Table 1, although the permanent set was small, the elastic set was also small and the cured product was found to be hard. In addition, tear strength is low,
It was confirmed that it was easy to tear.

Comparative Example 2 A base paste and a catalyst paste having the following compositions, which are different from the present invention in having no G component, were prepared. (Base paste) ・ 100 parts by weight of dimethylpolysiloxane blocked at both molecular chain terminals with dimethylvinylsiloxy group ・ 3 parts by weight of linear methylhydrogenpolysiloxane containing 40 mol% of methylhydrogensiloxane units ・ Poly Oxyethylene nonyl phenyl ether 10 parts by weight-Quartz 50 parts by weight (catalyst paste)-100 parts by weight dimethylpolysiloxane with both molecular chain terminals blocked by dimethylvinylsiloxy group-1,3 divinyltetramethyldisiloxane-platinum complex 0.4 weight 3% by weight Silicone oil solution containing 3% by weight ・ BET specific surface area is 100m ² / g, and the surface is (CH ₃ ) ₂ SiO _2/2.

An equal amount of the above-mentioned base paste and catalyst paste was collected, kneaded with a spatula for 30 seconds, and the same test as in Example 1 was performed. The results are summarized in Table 1. As shown in Table 1, although the permanent set was small, the elastic set was also small and the cured product was found to be hard. Also, the contact angle was larger than the compositions of the above Examples, and it was confirmed that the composition had poor wettability with water.

[0035]

[Table 1]

[0036]

As described in detail above, the silicone composition for dental impression according to the present invention has a large elastic strain, but a small permanent strain and is soft after hardening, so that the impression is removed from the oral cavity of the patient. Can be easily removed without causing any pain to the patient, and there is no risk of deformation or tearing at the time of removal, and after the model material such as plaster is injected into the obtained impression, the model material is removed. In this case, it has the effect that it can be easily removed.

Furthermore, the silicone composition for dental impression according to the present invention is excellent in wettability with water, and can precisely obtain an impression of details in the oral cavity, and fails to obtain a complex impression. This also has the effect that it can be performed reliably without performing.

As described above, the silicone composition for dental impression according to the present invention has succeeded in developing a material for dental impression having excellent performance overcoming the drawbacks of the conventional dental impression material, and has been developed by dentists. Of course, it is extremely useful from the standpoint of both patients and technicians, and is of great value in contributing to the dental field.

Claims (1)

[Claims] 1. A) 100 parts by weight of an organopolysiloxane having at least two aliphatic unsaturated hydrocarbons in one molecule. B) An organohydrogen having at least three hydrogen atoms directly bonded to a silicon atom in one molecule. Genpolysiloxane 0.1 to 30 parts by weight C) Silicone-soluble platinum compound (based on the total amount of A and B) 10 to 500 ppm D) Inorganic filler 10 to 500 parts by weight E) BET specific surface area 50 to 500 m ² / g And 5 to 50 parts by weight of finely divided silica whose surface has been hydrophobized F) 0.5 to 50 parts by weight of a nonionic surfactant G) 10 to 200 parts by weight of methylphenylpolysiloxane Impression silicone composition.