JPH07291820A - Coating material for silicone-based soft backing material - Google Patents

Abstract

PURPOSE:To obtain a coating material capable of forming a rubbery elastic coating layer exhibiting sufficiently high adhesive force, mechanical strength and surface slipperiness after curing and effective for improving the feeling to the tongue and avoiding the danger of generating a plaque-source caused by the adhesion of food residue. CONSTITUTION:This coating material for a silicone-based soft backing material contains (A) an organopolysiloxane having two or more organic groups having terminal unsaturated bond in the molecule, (B) >=0.5mol (based on 1mol of the unsaturated bond in the component A) of an organohydrogenpolysiloxane having three or more hydrogen atoms bonded to silicon atom in the molecule, (C) 0.1-1,000ppm (in terms of platinum atom based on the sum of the components A and B) of a platinum-based catalyst such as chloroplatinic acid or platinum- vinylsiloxane complex and, as necessary, (D) a volatile solvent such as toluene or methylene chloride. The viscosity of the coating material is 1-100 poise before curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for imparting lubricity to the surface of a silicone type soft lining material.

[0002]

2. Description of the Related Art Many dentures, especially full dentures, are elderly patients, and alveolar ridges generally have significant bone resorption, and the occlusal force per unit area is large. Since the alveolar ridge mucosa also becomes thin due to senile atrophy, the impact of occlusion and masticatory pressure will be transmitted directly to the alveolar bone without being alleviated. In addition, the thin mucous membrane sandwiched between the hard resin denture base and the hard alveolar bone is squeezed and scratched each time it bites, causing damage.

In such a difficult case, if a resin denture base is made only of a methyl methacrylate resin (acrylic resin) which is usually used, good results cannot be obtained for maintaining, stabilizing and supporting the denture. Therefore, it is necessary to line the mucosal surface of the resin denture base with a soft material or a soft dental lining material to compensate for the lost viscoelasticity of the alveolar ridge mucosa and provide a cushioning property to alleviate the impact during occlusion. In other words, it is the purpose of lining with a soft material to overcome various obstacles caused by the pressure of the submucosa by the hard material of the denture base.

As the soft lining material, a silicone rubber-based material having silica particles as a reinforcing material has been used as a relatively excellent lining material, but one of the problems is that it cannot be cut. That is, there was a point that the morphology could not be corrected after lining. Therefore, the present inventors have conducted diligent research aiming at the development of a silicone rubber-based soft lining material having machinability, and by using polyorganosilsesquioxane particles, which are silicone resin powders, as a filler, machinability is improved. It was found that the polyorganosilsesquioxane particles can be added to the cuttable silicone-based soft backing material.

[0005]

The silicone-based soft lining material having the above-mentioned machinability proposed by the present inventors has good machinability, but has a new problem that the cutting surface does not become smooth. Was found. The problem caused by the fact that the cutting surface of the silicone-based soft lining material does not become smooth is not only that the tongue, which has a particularly sensitive sensation in the human body, does not feel good, but food residues easily adhere to it. , Therefore, it may also be a source of plaque.

[0006]

By the way, in general, silicone rubber is used by filling silica powder such as fumed silica and precipitated silica as a reinforcing material. This is because the intermolecular force of the polysiloxane in the silicone rubber is usually very weak and the mechanical strength such as tear strength and tensile strength is small. Therefore, the use of the curable silicone rubber composition containing no reinforcing material has been limited to the use as a release material and a release material as disclosed in JP-A-60-190458.

As a result of intensive studies to solve the above-mentioned problems of the silicone-based soft lining material, the present inventors have found that a hydrosilylation reaction-curable silicone composition having a specific viscosity diluted with a volatile solvent as needed. When used as a coating material, good coating operability and sufficient mechanical strength after curing can be satisfied at the same time, and a thin coating layer can be formed on the surface of the silicone-based soft lining material. The coating layer firmly adhered to the silicone-based soft lining material, and it was found that the roughened silicone-based soft lining material surface can be provided with lubricity without impairing its durability, and the present invention was developed. It was

That is, the present invention comprises (A) 100 parts by weight of an organopolysiloxane having at least two organic groups having a terminal unsaturated bond in the molecule, and (B) a hydrogen atom bonded to a silicon atom in the molecule. An organohydrogenpolysiloxane having at least 3 of the above components is used in an amount such that the number of hydrogen atoms is 0.5 or more with respect to one unsaturated bond in the component (A). 0.1 to 1000 ppm based on the total amount of A) and component (B), and (D) 0 to 1000 parts by weight of a volatile solvent,
A coating material for a silicone-based soft lining material having a viscosity of 1 to 100 poises.

The component (A) used in the present invention is an organopolysiloxane having at least two organic groups having a terminal unsaturated bond in the molecule (hereinafter, abbreviated as unsaturated bond-containing silicone), which is the component (B). It is a main component that is crosslinked with an organohydrogenpolysiloxane (hereinafter abbreviated as SiH siloxane) to form a rubber elastic coating layer.

The unsaturated bond-containing silicone of the component (A) is an organopolysiloxane having at least two organic groups having terminal unsaturated bonds in one molecule, and the structure of other organic groups is not limited, and The linear or branched chain may be used, or a mixture thereof may be used.

Examples of the organic group having a terminal unsaturated bond include a vinyl group, an allyl group and a 1-butenyl group, but a vinyl group bonded to a silicon atom is preferred because of its easiness of synthesis and its reactivity. Most advantageous. These organic groups having a terminal unsaturated bond may be present at either or both ends of the molecular chain of the organosiloxane, or both of them, but they have excellent reactivity and rubber elasticity after curing. In order to have chemical and physical properties such as mechanical strength of the coating layer, it is preferable that at least one is present at the terminal.

Examples of the organic group bonded to a silicon atom other than the organic group having a terminal unsaturated bond include a methyl group, an ethyl group,
Alkyl groups such as propyl group, butyl group, octyl group, aryl groups such as phenyl group, chloromethyl group, 3,
Substituted alkyl groups such as 3,3-trifluoropropyl group are exemplified, and among them, it is easy to synthesize, and the rubber elastic coating layer after curing has good chemical strength such as sufficient mechanical strength and coloring resistance. The methyl group is most preferable from the viewpoint of maintaining the physical and physical properties.

Typical examples of the unsaturated bond-containing silicone used in the present invention are as follows.

[0014]

[Chemical 1]

(However, Ph represents a phenyl group) and the like. The bonding order of the repeating structural units in the compounds and the compounds used in Examples and Comparative Examples described below is completely arbitrary, and the number of repeating structural units shown in the structural formula is simply the total amount of each structural unit. It only shows the average value.

The SiH siloxane of the component (B) in the present invention is a component having a function of crosslinking the above unsaturated bond-containing silicone to form a rubber elastic coating layer. In order to react with the unsaturated bond-containing silicone to form a crosslinked structure, at least three hydrogen atoms bonded to silicon atoms are necessary in the molecule. If the number is less than 3, a crosslinked structure does not occur and a rubber elastic coating layer cannot be obtained.

Examples of the organic group bonded to a silicon atom other than a hydrogen atom include those similar to the organic group having a terminal unsaturated bond and the organic group having no terminal unsaturated bond in the component (A). However, the methyl group is most preferable because it is easy to synthesize and retains sufficient mechanical strength and good chemical and physical properties such as color resistance after curing. The SiH siloxane may be linear, branched or cyclic, and may be a mixture thereof.

Typical examples of the SiH siloxane used in the present invention are shown below.

[0019]

[Chemical 2]

(However, Ph represents a phenyl group) and the like. Also in the SiH siloxanes used in Examples and Comparative Examples described above and below, the bonding order of each repeating constitutional unit in the molecule is completely arbitrary as in the unsaturated bond-containing silicone, and the repeating constitutional unit shown in the structural formula is shown. The number of s only indicates the average value of the total amount of each constitutional unit. .

The unsaturated bond-containing silicone and S in the present invention
The amount of each iH siloxane compounded varies greatly depending on its molecular weight, but normally, one unsaturated bond in the unsaturated bond-containing silicone has 0.5 or more hydrogen atoms bonded to the silicon atom in the SiH siloxane, It is preferable to mix them in a ratio of 1 to 10. If this ratio is too small, the curability becomes insufficient, and if it is too large, the resulting rubber elastic coating layer becomes brittle or excess hydrogen atoms bonded to silicon atoms remain, so that the stability of the rubber elastic coating layer over time is reduced. It tends to decrease.

The hydrogen atom bonded to the silicon atom by the organohydrogenpolysiloxane having at least three hydrogen atoms bonded to the silicon atom in the molecule is equivalent to one unsaturated bond in the unsaturated bond-containing silicone. If it is 0.5 or more, an organohydrogenpolysiloxane containing only two or one hydrogen atom bonded to a silicon atom in the molecule may be added.

As the component (C) platinum catalyst used in the present invention, any catalyst can be used as long as it can be used in a usual hydrosilylation reaction. For example, chloroplatinic acid, its alcohol modified product, or platinum. A vinyl siloxane complex etc. can be mentioned. In order to improve the storage stability, a substance having a low chlorine content such as a platinum vinylsiloxane complex is preferable.

The content of the platinum catalyst may be in the range of 0.1 to 1000 ppm with respect to the total weight of the unsaturated bond-containing silicone and SiH siloxane as the platinum content. If the blending amount is less than 0.1 ppm, the crosslinking reaction between the unsaturated bond-containing silicone and SiH siloxane does not proceed sufficiently, and if the blending amount is more than 1000 ppm, when the rubber elastic coating layer becomes yellow due to platinum black precipitation, or is severe. Problems such as black coloring and difficulty in controlling the crosslinking reaction occur.

The volatile solvent of the component (D) used in the present invention is a volatile solvent capable of simultaneously dissolving the components (A), (B) and (C), and is a mixture of these mixtures before curing. It is used to adjust the viscosity to be 1-100 poise. Examples of this volatile solvent include methylene chloride, toluene, tetrahydrofuran and the like,
Of these, methylene chloride is most preferred because of its high volatility. The amount of the volatile solvent to be added may be selected so that the viscosity of the composition of the present invention before curing is 1 to 100 poises, and substantially depends on the viscosities of the components (A) and (B). The blending amount is determined. Usually component (A) 1
It is used in an amount of 1000 parts by weight or less with respect to 00 parts by weight, but when the viscosity of the mixture containing the components (A), (B) and (C) as basic components is already in the range of 1 to 100 poises. No need to use volatile solvents.

The viscosity of the composition of the present invention needs to be adjusted to be 1 to 100 poise. When the viscosity is less than 1 poise, that is, the viscosity of the component (A) unsaturated bond-containing silicone, that is, the viscosity is low because the molecular chain is short and the overall viscosity is less than 1 poise, it is sufficient for the rubber elastic coating layer after curing. In addition, the component (A) unsaturated bond-containing silicone has a sufficient viscosity, that is, the molecular chain length, but the addition of the component (D) volatile solvent results in an overall viscosity of less than 1 poise. If it is small, a sufficient thickness of the rubber elastic coating layer cannot be secured, and thus sufficient surface lubricity cannot be obtained. On the other hand, if the viscosity is higher than 100 poise, problems such as poor operability, thick rubber elastic coating layer after curing, and insufficient mechanical strength occur. The viscosity specified in the present invention means the viscosity before curing of the curable composition comprising the above-mentioned essential components.

If desired, the coating material of the present invention may further contain other additives within the range in which the physical properties thereof are not significantly lowered and the above viscosity is maintained. Such additives include pulverized quartz, fused silica, wet silica, silica-based powder such as dry silica, silicone resin powder such as polymethylsilsesquioxane particles, polytetrafluoroethylene, fluorocarbon resin powder such as polyvinylidene fluoride. Fillers such as carbon black, glass fiber, crushed polymer, powdered polymer, composite filler (crushed composite of inorganic oxide and polymer), non-reactive silicone, reaction inhibitor, UV absorber, plasticizer, Pigments,
Examples include antioxidants and antibacterial agents.

The coating material for a silicone-based soft lining material of the present invention is usually an unsaturated bond-containing silicone, a platinum catalyst and, if necessary, a backing agent containing a volatile solvent and other additives, and a SiH siloxane and a necessary component. It is generally prepared as a two-pack type consisting of an unsaturated bond-containing silicone, an Otsuka drug containing a volatile solvent and other additives, and the two are generally mixed and used immediately before use.

The preparation method is as follows: unsaturated bond-containing silicone,
SiH siloxane, platinum catalyst, volatile solvent, and additives are weighed in appropriate amounts and mixed in a mixing container or kneaded with a general kneader such as a kneader or planetary machine until uniform. A viscous liquid or pasty composition can be obtained. At this time, if a volatile solvent is included, they must be mixed in a closed container.

The method of using the coating material of the present invention is to measure and knead an appropriate amount of two kinds of liquids or pastes of A and B immediately before use, apply the mixture to the coated portion of the silicone-based soft lining material, and sufficiently cure as it is. Hold until done.

In the coating material for a silicone-based soft backing material of the present invention, at least two vinyl groups are present in the molecule as an organic group having a terminal unsaturated bond, and a methyl group is provided as an organic group other than the organic group. Unsaturated bond-containing silicone, wherein SiH siloxane having at least three hydrogen atoms bonded to silicon atoms in the molecule and having a methyl group as an organic group bonded to silicon atom is unsaturated in the unsaturated bond-containing silicone. An amount such that the number of hydrogen atoms is 1 to 10 with respect to one bond, and the platinum / vinylsiloxane complex is an unsaturated bond-containing silicone and SiH in terms of platinum atom.
It contains 0.1 to 1000 ppm with respect to the total amount of siloxane, and optionally a volatile solvent, and has a viscosity of 1 to
The 100-poise coating material for silicone-based soft lining material is a raw material, easy to synthesize, polymerization reactivity, operability, mechanical hardness of the rubber elastic coating layer after curing, chemical resistance such as coloring resistance, This is a preferred embodiment because it is particularly excellent in physical properties.

[0032]

The coating material for a silicone type soft lining material obtained by the present invention has a strong adhesive force with the silicone type soft lining material after curing, and has sufficient mechanical strength and a smooth surface. It is possible to form an elastic coating layer having As a result, it is possible to lubricate the surface of the silicone-based soft lining material roughened by cutting, improve the feel of the tongue, and avoid the risk of plaque generation due to the adhesion of food residues. It was

[0033]

EXAMPLES Examples will be shown to more specifically describe the present invention, but the present invention is not limited to these examples.

The unsaturated bond-containing silicones used in the following examples and comparative examples are shown in Table 1, and SiH siloxanes are shown in Table 2.
Shown in.

[0035]

[Table 1]

[0036]

[Table 2]

In the examples and comparative examples, the coating material was evaluated by the following method, and the same sample was measured or evaluated three times and the average value was recorded.

(1) Test Material As the silicone type soft lining material, the following two kinds of pastes A and B were prepared. These were kneaded in equal amounts and cured to obtain a silicone rubber cured product. The surface of this hardened body is ground with a paper cone (Harukosha: paper cone, rough) using a dental engine to roughen the surface. On this surface, take the required amount of each of the liquids and pastes of A and B, knead and apply, and leave at 37 ° C in air for 10 minutes,
Let it harden. The operability at that time, the change in glossiness before and after curing, and the strength of the coating layer were measured by the following methods.

A paste: Compound 100 parts by weight Polymethylsilsesquioxane fine particles (particle size 2 μm) 100 parts by weight Platinum / vinyl siloxane complex solution (platinum 1000 ppm) 1 part by weight B paste: Compound 97 parts by weight Compound 3 parts by weight Poly 100 parts by weight of fine particles of methylsilsesquioxane (particle size: 2 μm) The tensile strength of the silicone rubber cured product prepared here is about 20 Kgf / cm ² .

(2) Operability Take the required amount of liquid or paste for each of A and B,
Knead with a small brush and apply to the surface of the roughened silicone rubber cured product. The operability at that time was evaluated. The evaluation points were evaluated according to the following three criteria: A, B and C.

A: good B: almost good C: bad (how bad the condition is recorded in the table) (3) Glossiness Before and after coating with the silicone-based soft backing material coating material of the present invention The glossiness of the surface of the cured silicone rubber is measured with a gloss meter (manufactured by Tokyo Denshoku Co., Ltd .: TC-108D, incident angle: 4).
5 °). In addition, the glossiness of the roughened surface before coating was 1.5%, and the glossiness of the smooth surface obtained by pressing and curing the pp sheet was 62.0%.

(4) Strength of coating layer The surface of the cured silicone rubber coated with the coating material for a silicone-based soft backing material of the present invention was scratched with a stainless spatula, and the state of destruction was evaluated. The evaluation points are A, B, according to the following criteria.
It was evaluated in 3 grades of C. The strength of the coating layer in this case represents the total strength including the mechanical strength of the coating layer itself and the adhesive strength with the silicone-based soft lining material.

A: No destruction B: Partial destruction C: Destruction Example 1 100 parts by weight of the compound shown in Table 1 and platinum vinylsiloxane complex were added in an amount such that platinum was 50 ppm with respect to the total amount of the compound. The mixture was placed in a flask and stirred to prepare an upper agent.

100 parts by weight of the compound shown in Table 1 and 40 parts by weight of the compound shown in Table 2 were placed in a flask and stirred to prepare a second preparation.

The above-mentioned former agent and the second agent were mixed with stirring in an amount of 1: 1 to form a coating material, which was evaluated according to the above-mentioned evaluation method. The results are shown in Table 4.

Examples 2 to 11 and Comparative Examples 1 to 5 As in Example 1, materials having the respective compositions shown in Table 3 were mixed with a powder component by stirring in a flask without the powder component. Was kneaded with a planetary to prepare a liquid or paste (upper skin agent, second preparation). The same platinum catalyst as that used in Example 1 was used.

[0047]

[Table 3]

[0048]

[Table 4]

The backing agents and the second agents of the respective Examples and Comparative Examples were stirred and mixed in the amounts shown in Table 3 to prepare coating materials, and the tests were carried out according to the above-mentioned evaluation methods. The results are shown in Table 4.

[0050]

[Table 5]

From the results shown in Table 4, the silicone-based soft lining material coating materials (Examples 1 to 11) of the present invention have good operability, impart a glossy surface, and have a sufficient coating layer. It can be seen that it has strength. On the other hand, in the comparative example, when the number of hydrogen atoms bonded to the silicon atom in the component (B) was less than 3 (Comparative Example 1), the composition was not cured, and the viscosity before mixing was 1 before curing. If it is less than poise (Comparative Examples 2 and 3), sufficient surface gloss and sufficient coating layer strength cannot be obtained, and if the viscosity before mixing is 100 poise or more (Comparative Example 4), the operability becomes poor and the component ( The number of hydrogen atoms bonded to the silicon atom in B) is the component (A).
When the number of unsaturated bonds is less than 0.5 with respect to one (Comparative Example 5), the paste is not sufficiently cured. Thus, it is understood that in all cases of Comparative Examples, good properties are not exhibited as a coating material for a silicone-based soft backing material.

Claims (1)

[Claims] 1. An organopolysiloxane (A) having at least two organic groups having a terminal unsaturated bond in the molecule (A).
00 parts by weight of (B) an organohydrogenpolysiloxane having at least 3 hydrogen atoms bonded to silicon atoms in the molecule, and the hydrogen atom of which is 0. An amount of 5 or more, 0.1 to 1000 ppm of (C) platinum catalyst in terms of platinum atom based on the total amount of component (A) and component (B), and (D) volatile solvent 0
A coating material for a silicone-based soft backing material, characterized in that the coating material contains ˜1000 parts by weight and has a viscosity of 1 to 100 poise.