JPH0536459B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a curable silicone composition, and particularly to a curable silicone composition suitable for dental impression materials. [Prior Art] Addition-curable curable silicone compositions are widely used as impression materials. This curable silicone composition has excellent curability, has very small shrinkage during curing, and does not produce any by-products, and the cured product has excellent dimensional stability, is tasteless and odorless, and is easily demolded. It has excellent properties such as However, since this conventional curable silicone composition is hydrophobic, if the surface on which the impression is to be taken is wet, it does not blend well with the surface, making it difficult to obtain an accurate impression. For example, when using it as a dental impression material to take a mold of a moist oral cavity,
It is difficult to obtain a detailed and precise impression;
Furthermore, when a model is produced by casting gypsum mud onto the impression obtained, there is a problem with the wetness of the gypsum mud to the impression, making it difficult to obtain an accurate model. Therefore, attempts have been made to spray a detergent solution onto the surface of the impression immediately before casting the plaster mud to make it hydrophilic, and also to use a curable silicone composition containing a nonionic surfactant [Lacy, A. .，
Treleaven, S. & Tendresen, M., Cal. Dent.
Assn.J., 5, 36-40 (1977), Norling, D.K.
Reisbick, MH, J. Pros. Dent., 42, 342−347.
(1979)] has been proposed. Additionally, U.S. Patent No.
No. 4657959, U.S. Patent No. 4752633, JP-A-62-
Japanese Patent No. 252706 proposes a method for solving these problems by adding a silicone-modified polyether compound to a silicone composition as a hydrophilic agent. [Problems to be Solved by the Invention] However, in the curable silicone composition containing the above-mentioned nonionic surfactant, if a large amount of nonionic surfactant is not blended, the gypsum mud will not be able to cure the cured product. It shows no wettability. Furthermore, when a large amount of nonionic surfactant is blended, the curing reaction of the composition is hindered, causing problems such as increased ice distortion of the cured product and deterioration of various physical properties. Furthermore, in these methods, since the hydrophilic group is a polyether group, the long-term storage stability required for use as an impression material is not good. Furthermore, when stored for a long period of time or when heated during transportation or storage, it decomposes and generates aldehyde, and for example, when used as a dental impression material, the aldehyde odor causes discomfort to patients. . There were problems such as slow curing reaction. SUMMARY OF THE INVENTION An object of the present invention is to provide a curable silicone composition that has good curing properties, good physical properties of the cured product, and can yield a cured product that has excellent hydrophilicity. [Means for Solving the Problems] In order to solve the above problems, the present invention provides (A) an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom in one molecule; ) an organohydrodiene polysiloxane having at least three silicon-bonded hydrogen atoms in one molecule, (C) a platinum group metal catalyst, and (D) the following general composition formula (): R ¹ _a R ² _b SiO _(4-ab)/2 () In the formula, a is a number of 0.05<a<2.5, b is a number of 0.1<b<0.35, R ¹ is a hydrogen atom or a monovalent hydrocarbon group, R ² is the following formula (): -R ³ OCH ₂ C (CH ₂ OH) _c R ⁴ _d () (wherein, R ³ is a divalent hydrocarbon group, R ⁴ is a monovalent hydrocarbon group, and c is 2 or 3, d is 0 or 1
The organohydrodiene polysiloxane of component (B) contains a silicone compound represented by the following, which is a polyol group represented by The number of bonded hydrogen atoms is 0.5 to 10 per aliphatic unsaturated hydrocarbon group in component (A), and the catalyst of component (C) is a platinum group metal. In conversion, the above
The silicone compound of component (D) is blended in an amount of 0.1 to 500 ppm relative to component (A).
The present invention provides a curable silicone composition characterized in that the composition is blended in an amount of 0.1 to 20 parts by weight per 100 parts by weight. The organopolysiloxane which is component (A) of the composition of the present invention contains at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom in one molecule, and may be linear, branched or It may be in the form of a two-dimensional or three-dimensional network structure, or a mixture thereof. Examples of aliphatic unsaturated hydrocarbon groups include vinyl groups,
Examples thereof include an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a vinyl group is preferable.
Examples of organic groups bonded to silicon atoms other than aliphatic unsaturated hydrocarbon groups include alkyl groups such as methyl, ethyl, and propyl; aromatic hydrocarbon groups such as phenyl and tolyl; cyclohexyl, Alicyclic hydrocarbon groups such as cycloheptyl groups; or groups in which some or all of the hydrogen atoms bonded to carbon atoms of these hydrocarbon groups are substituted with halogen atoms, etc., such as chloromethyl groups, 3 ,3,3
-trifluoropropyl group, etc. Among these, preferred are methyl group,
They are a phenyl group and a 3,3,3-trifluoropropyl group. In particular, preferred organopolysiloxanes (A) include those in which all substituents other than aliphatic unsaturated hydrocarbon groups are methyl groups;
Or it consists of a methyl group and a phenyl group. The viscosity of the organopolysiloxane of component (A) at 25°C is usually 50 cSt or more, preferably 100 cSt or more.
~5000000cSt. The organohydrodiene polysiloxane which is component (B) of the composition of the present invention has at least three hydrogen atoms bonded to a silicon atom in one molecule, and can be linear, branched, or cyclic. It may have a structure, preferably a linear structure. In this organohydrodiene polysiloxane, organic groups other than hydrogen atoms bonded to silicon atoms are the same as those exemplified as substituents other than aliphatic unsaturated hydrocarbon groups in the organopolysiloxane (A) above. can be mentioned. The viscosity of component (B) organohydrodiene polysiloxane at 25°C is usually 2 to 2.
1000 cSt, preferably 5 to 150 cSt. The blending amount of component (B) in the composition of the present invention is usually such that the hydrogen atom bonded to a silicon atom in component (B) is equal to one aliphatic unsaturated hydrocarbon group in component (A).
The amount is preferably 0.5 to 10, more preferably 0.75 to 5. In addition, if component (D) below has a carbon atom or aliphatic unsaturated hydrocarbon group bonded to a silicon atom, the above ratio including the hydrogen atom or aliphatic unsaturated hydrocarbon group shall be maintained. It is preferable to adjust the blending amounts of component (B) and component (D). If the ratio of hydrogen atoms bonded to silicon atoms to aliphatic unsaturated hydrocarbon groups in the composition is too small, the curability will be insufficient, and if this ratio is too high, the resulting cured product will become brittle or Since the Si-H groups remain, the stability of the cured product over time decreases. The platinum group metal catalyst which is component (C) of the composition of the present invention is not particularly limited as long as it is used for addition-curing type curable silicone. Examples include those supported on chloroplatinic acid, alcohol-modified chloroplatinic acid, platinum-vinylsiloxane complexes, and complexes of chloroplatinic acid and olefin.
Particularly preferred are alcohol-modified chloroplatinic acid, platinum-vinylsiloxane complexes, and complexes of chloroplatinic acid and olefin from the viewpoint of storage stability, reactivity, etc. of the resulting composition. The blending amount of component (C) is adjusted as appropriate to obtain the desired curing speed, but it is usually 0.1 to 0.1% of component (A) in terms of platinum group metal (catalyst metal).
500 ppm, preferably 1 to 300 ppm. If the amount of component (C) is too small, poor curing tends to occur. The silicone compound as component (D) of the composition of the present invention has the general compositional formula (): [In the formula, R ¹ is a hydrogen atom or a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, and butyl; aromatic hydrocarbon groups such as phenyl and tolyl; or bonds to carbon atoms of these groups. Some or all of the hydrogen atoms are fluorine,
Groups substituted with halogen atoms such as chlorine,
For example, 3,3,3-trifluoropropyl group,
Substituted hydrocarbon groups such as chloromethyl group; or vinyl groups, allyl groups, aliphatic unsaturated hydrocarbon groups, and the like. R ² is the following formula (): -R ² OCH ₂ C (CH ₂ OH) _c R ⁴ _d () (wherein, R ³ is a divalent hydrocarbon group, such as a methylene group, a propylene group, a tetra An alkylene group such as a methylene group or a pentamethylene group, preferably a propylene group; ^R4 is a monovalent hydrocarbon group, such as a methyl group,
ethyl group, propyl group, etc., preferably ethyl group; c is 2 or 3, d is 0 or 1, and c+d=3), and a is 0.05< a
<2.5, b is a number 0.1<b<0.35. ] is used. Preferred specific examples of the silicone compound as component (D) include the following formula (): [In the formula, multiple R may be the same or different,
It is a monovalent hydrocarbon group, and in the above formula ()
Examples of R ¹ include saturated hydrocarbon groups among those exemplified, and preferably a methyl group. R ⁵ is a hydrogen atom or an aliphatic unsaturated hydrocarbon group exemplified as R ¹ in () above, and preferably a hydrogen atom or a vinyl group. R ⁶ is the same as R ² represented by the above formula (). Moreover, x is an integer of x≧0, preferably an integer of 0 to 10,
y is an integer of y≧1, preferably an integer of 1 to 10, and z is an integer of z≧0, preferably an integer of 0 to 10. Furthermore, it is preferable that x=0, y is an integer of 1 to 5, and z is an integer of 0 to 5, particularly x=
It is preferable that 0 and y are integers of 1 to 5, and z is 0 or 1. ] Examples include the following. The silicone compound represented by the above formula () is
It can be manufactured by a method known in the art. For example, it is produced by reacting an organohydrodiene polysiloxane having one or more hydrogen atoms bonded to a silicon atom in one molecule and a polyhydric alcohol having an alkenyl group at the end in the presence of a platinum catalyst. be able to. After the reaction is completed, unreacted substances are distilled off, and the resulting reaction mixture is usually treated with activated carbon as a mixture of a plurality of silicone compounds represented by the formula (). This mixture may be used as it is as component (D), or each compound may be isolated by distillation or the like and used alone. The amount of component (D) is usually, preferably, component (A).
The amount is 0.1 to 20 parts by weight, more preferably 0.2 to 15 parts by weight, particularly preferably 0.5 to 5 parts by weight, per 100 parts by weight. If the amount of component (D) is in the range of 0.1 to 20 parts by weight, moderate hydrophilicity can be obtained and it is also preferable in terms of dimensional stability of the model. In addition to the above-mentioned components (A) to (D), the composition of the present invention also includes components that are usually added to curable silicone compositions, such as fillers, dyes, pigments, reinforcing agents, metal powders, fragrances, and fluids. A property regulator, a plasticizer, a reaction inhibitor, etc. may be added as appropriate. For example, as a reinforcing filler,
Examples include fumed silica, precipitated silica, quartz powder, fused silica powder, diatomaceous earth, calcium carbonate, etc. Dyes or pigments include inorganic pigments such as titanium oxide, cobalt aluminate, titanium yellow, red iron oxide, carbon black, etc. Examples include pigments and pigments. The composition of the present invention is usually prepared as a two-component type consisting of two agents, A and B, each containing component (A) and component (B), in which component (D) is bonded to a silicon atom. If it does not have either a hydrogen atom or an aliphatic unsaturated hydrocarbon group, it may be added to both or either agent A or agent B. When the agent has either a silicon-bonded hydrogen atom or an aliphatic unsaturated hydrocarbon group, component (D) is incorporated into either one of the agents. In other words, if component (D) has a hydrogen atom bonded to a silicon atom, the agent containing component (B) may contain an aliphatic unsaturated hydrocarbon group bonded to a silicon atom. , is added to Agent A containing component (A). However, even when component (D) has either a hydrogen atom bonded to a silicon atom or an aliphatic unsaturated hydrocarbon group, a reaction inhibitor may be added to (A), (B), (C) and ( It can also be prepared as a one-component product containing component D) at the same time. Examples of the reaction inhibitor used include acetylene alcohols, siloxane-modified acetylene alcohols,
Examples include organopolysiloxanes having a high density of vinyl groups, such as tetravinyltetramethylcyclotetrasiloxane. The composition of the present invention can be cured in a short period of time, for example, within a few minutes, even at room temperature, by mixing the components at the time of use. Even during and after curing, the composition of the present invention has hydrophilic properties and has good wettability to hydrophilic substances or water-containing substances. Therefore, accurate impressions can be obtained even when used in a humid atmosphere in the oral cavity, making it particularly suitable as a dental impression material. It can also be widely used as a molding material or for other purposes that require hydrophilicity. [Example] Next, the method of the present invention will be explained in detail with reference to Examples and Comparative Examples. In addition, in the following example,
"Part" indicates "part by weight", and viscosity indicates a value measured at 25°C. Examples 1 and 2, Comparative Examples 1 and 2 Dimethylpolysiloxane oil whose molecular chain ends are blocked with dimethylvinylsiloxy groups and whose viscosity is 100 cSt, whose relative viscosity in xylene solution is 2.8 and whose molecular chain ends are dimethylvinyl Dimethylpolysiloxane raw rubber (vinyl group content: 0.0025 mol%) capped with siloxy groups, methylhydrodiene cypolysiloxane (methylhydrodiene) with a viscosity of 12 cSt, with both ends of the molecular chain capped with dimethylhydrodiene siloxy groups. Siloxy unit content: 33 mol%), octyl alcohol solution of chloroplatinic acid (platinum content: 1% by weight), average particle size 4 μm
quartz powder, liquid paraffin, and diatomaceous earth with an average particle size of 2 μm according to the formulation shown in Table 1.
Mixing and stirring, paste-like materials A ₁ to _{A 3} and B ₁ to B ₃
was prepared. Furthermore, a paste-like substance is added as component (D).
Nothing was added to B ₁ , and a compound represented by the following formula (): CH ₂ = CHCH ₂ OCH ₂ C (CH ₂ OH) ₂ C ₂ H ₅ () was added to the paste B ₂ , and the paste was For object _B3 , the following formula (): A compound represented by was blended. A composition was prepared by quickly mixing 1 g each of B ₁ , B ₂ and B ₃ with 1 g each of these pastes A ₁ , A ₂ and A ₃ , and then the resulting composition was spread on a glass plate. Diameter 19mm x thickness 1mm placed on top
The mixture was poured into a cylindrical mold, and after removing the excess with a spatula, the mixture was covered with a glass plate and allowed to harden at room temperature for 10 minutes. Next, one drop of distilled water was carefully placed on the surface of the cured product, and the contact angle between the water drop and the surface of the cured product was measured using a goniometer after 30 seconds and 3 minutes. The results are shown in Table 1.

【table】

〔Effect of the invention〕

The curable silicone composition of the present invention has a cured product having excellent hydrophilicity, and is suitable as a molding material used in a humid atmosphere, particularly as a molding material for dental impression materials and the like.

Claims (1)

[Scope of Claims] 1 (A) an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups bonded to a silicon atom in one molecule; (B) an organopolysiloxane having a hydrogen atom bonded to a silicon atom in one molecule; an organohydrodiene polysiloxane having at least three elements, (C) a platinum group metal catalyst, and (D) the following general compositional formula (): R ¹ _a R ² _b SiO _(4-ab)/2 () where, a is a number of 0.05<a<2.5, _b is a number of 0.1<b<0.35, ^R1 is a hydrogen atom or a monovalent hydrocarbon group, ^R2 is the following formula (): ^-R3OCH2 C(CH ₂ OH) _c R ⁴ _d () (wherein, R ³ is a divalent hydrocarbon group, R ⁴ is a monovalent hydrocarbon group, c is 2 or 3, and d is 0 or 1
The organohydrodiene polysiloxane of component (B) contains a silicone compound represented by the following, which is a polyol group represented by The number of bonded hydrogen atoms is 0.5 to 10 per aliphatic unsaturated hydrocarbon group in component (A), and the catalyst of component (C) is a platinum group metal. In conversion, the above
The silicone compound of component (D) is blended in an amount of 0.1 to 500 ppm relative to component (A).
A curable silicone composition characterized in that it is blended in an amount of 0.1 to 20 parts by weight per 100 parts by weight.