JPH0243209A - Silicone resin, manufacture of the same and dental adhesive comprising the same - Google Patents

Abstract

PURPOSE:To provide a silicone resin which exhibits excellent adhesion when used as an adhesive between a silicone rubber backing material and an artificial tooth bed, is excellent in water resistance, and can be used in the mouth for a long period of time, by using a copolymer comprising a combination of specific repeating units. CONSTITUTION:The title silicone resin is a copolymer comprising repeating units of formula I, II, III and IV, the combination being any of (a), (b) or (c) given below, wherein the repeating units are bonded in an arbitrary order with the numbers being arbitrary: (a) formulae I and IV, (b) formulae II and IV and (c) formulae of III and IV. In formulae I-IV, R<1> and R<7> may be the same or different and each is hydrogen or a lower alkyl group; R<2>, R<3>, R<4> and R<8> may be the same or different and each is a lower group; R<5> and R<6> may be the same or different and each is a lower alkyl group or a vinyl group; and T<1> and T<2> may be the same or different and each is a lower alkylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a new silicone resin, a method for producing the same, and a dental adhesive for which the resin is used.

[Prior art] When a patient with dentures uses dentures, as the user ages, the alveolar ridge atrophies and the jaw mucosa becomes thinner, making it difficult for the denture base to stably fit into the alveolar ridge. In addition, there is a problem in that the jaw mucosa loses its ability to relieve occlusal pressure, resulting in pain during occlusion. In order to prevent such inconveniences, the mucosal surface of the denture base is generally lined with an elastic material.

Various types of lining materials have been used as such elastic lining materials, including acrylic resins, polyolefin resins, and fluorine resins, but silicone rubber lining materials also have extremely excellent elasticity. Room temperature curing silicone rubber [hereinafter referred to as RT V (Room Te
low-temperature curing silicone rubber that cures at a low temperature of about 50 to 150°C [hereinafter referred to as LTV (
Low Temperature Vulcanizin
g) Silicone rubber, which is sometimes called silicone rubber, has attracted attention because it is easy to handle.

[Problems to be Solved by the Invention] However, silicone-based lining materials have a drawback of poor adhesion to denture bases. Various adhesives have been proposed for bonding these, but some have excellent adhesion and water resistance.
Moreover, an adhesive that can be used in the oral cavity for a long time has not yet been developed.

[Object of the invention] The present invention has been made in view of the above circumstances, and
The purpose is to use it as an adhesive for RTV and LTV silicone rubber backing materials and tooth bases.It is a novel product that exhibits excellent adhesive properties, has excellent water resistance, and can be used for a long time in the oral cavity. An object of the present invention is to provide a silicone-based δ1 fat and a method for producing the same.

In the Naoki specification, dental adhesives are typically explained as a use of the silicone resin itself of the present invention, but the use is not limited to dental adhesives, but general industrial uses. Applicable to In addition, hereinafter, when silicone rubber is referred to in this specification, it refers to RTV silicone rubber and LT.
V silicone rubber.

[Structure of the invention]

The silicone resin according to the present invention has repeating elements (I) to (II+) represented by the following general formula, and these repeating elements are any of the following ((), (B1), or (restriction)). Any number of these combinations are combined in any repetition order.

(a) (■) and (III) (b) (11) and (III) (viii) (It') and (III) OR' [wherein R' and R7 are hydrogen or a lower alkyl group, R2
, R3, R4 and R6 are lower alkyl groups, R5 and R6
are the same or different lower alkyl group or vinyl group,
T1 and T2 mean a lower alkylene group] Furthermore, the invention of the method for producing the silicone resin described above includes the following three reaction procedures.

First method: (Ia) (IIIa)0-
T' -St -OR'OR'OR' (■) [In the formula, Rl, R2, R3R4R? R8, -r +
and T2 have the same meaning as before. Further, the number of reacting molecules of the raw material compounds (I a) and (O+ a) is arbitrary, and m and n are arbitrary repeating numbers, and this silicone resin (■)
means that any number of these repeating elements are connected in any order in a chain. Second method: (IV) (III a) (V) (■) [In the formula, R', R', Ra & T2 have the same meanings as above, R9 and RIO have the same or different meanings and represent a lower alkyl group or vinyl group, and Y represents halogen. Also, the raw material compound (
The number of reaction molecules in IV) and (IIIa) is arbitrary, m and n are arbitrary repeating numbers, and this copolymer compound (V) is a compound in which these repeating elements are chained in an arbitrary number and in an arbitrary order. 3rd method: (IVa) OR' (IIIa) (Vo) (■°) [wherein R1, R7, Ra, R9, Rlo, z and T2 are the same as before meaning. In addition, the raw material compound (IVa) and (
The number of reacting molecules in III a) is arbitrary, m and n are arbitrary repeating numbers, and this copolymer compound (■°) has arbitrary numbers of these repeating elements.

It means that they are bonded in a chain in an arbitrary order] Also, the above silicone resin (■) is used as an adhesive between the resin denture base and the condensed silicone rubber lining material, and the resin denture base and It is also an important feature of the present invention to use the silicone resin (■) or (■°) as an adhesive for the additional type silicone rubber backing material.

Next, the definition of the above general formula will be explained. The term "lower" used in this specification means one having 1 to 6 carbon atoms.

RI R2R3R4R8, Re, R7R6,
The lower alkyl group represented by R9 and RIG is a linear or branched saturated aliphatic hydrocarbon residue, and specific examples thereof include methyl, ethyl, propyl, isopropyl, tertiary butyl, pentyl, neopentyl,
Examples include tertiary pentyl and hexyl, and more preferably an alkyl group having 1 to 3 carbon atoms.

In addition, the lower alkylene groups represented by T1 and T2 include ethylene, propylene, isopropylene, butylene,
Examples include isobutylene.

Furthermore, active esters represented by Z include para-nitrophenoxycarbonyl, para-nitrophenylthiocarbonyl, 2,4,6-dolichlorophenoxycarbonyl and (2,3,4,5-tetrahydro-2,5-dioxovirol- 1-yl)oxycarbonyl (also known as (N→succinyliminooxycarbonyl)).

Next, silicone resins (■), (■) and (■
The manufacturing method for (°) will be explained.

fa) Method for producing silicone resin (■) Compound (I
a) Ten compound (Illa)-”Silicone resin (■)
The reaction compound (Ia) is reacted with the compound (IIIa) in the presence of an organic solvent and a polymerization initiator.

Examples of the organic solvent used here include toluene, xylene, benzene, and other solvents that do not adversely affect the progress of this reaction. Examples of the polymerization initiator include polymerization catalysts that do not adversely affect the progress of this reaction, such as benzoyl peroxide (BPO), acetyl peroxide, and azobisisobutyronitrile (AIBN). The reaction is preferably carried out in the presence of an inert gas such as nitrogen gas. Although the reaction temperature is not particularly limited, the reaction is usually carried out at or under heating.

(b) Process for producing silicone resin (■) (1) Reaction of compound (+V) and compound (Illa)-=copolymerization of compound (!V) in the presence of a solvent and a polymerization initiator. Compound (IIIa) is reacted. Examples of the organic solvent used in this case include solvents that do not adversely affect the progress of this reaction, such as isopropanol, toluene, and xylene. Also, as a polymerization initiator, LfA I BN, BP
Examples include O, acetyl peroxide, and the like. The reaction is preferably carried out in the presence of an inert gas such as nitrogen gas.

Although the reaction temperature is not particularly limited, the reaction is usually carried out at or under heating.

(2) Copolymerization (V) - Reaction of compound (Vl) - silicone resin (■) Reacting compound (Vl) with copolymerization compound (V) in the presence of an organic solvent and a dehalogenating agent such as triethylamine. . Examples of organic solvents in this case include solvents that do not adversely affect the progress of this reaction, such as tetrahydrofuran (THF), chloroform, and dichloroethane.

(C) Manufacturing method of silicone resin (■゛) (1) Compound (IVa) 10 Compound (III a) → Copolymerization (Vo
) Compound (IVa) is reacted with compound (IIIa) in the presence of an organic solvent and a polymerization initiator. Organic solvents used in this case include isopropanol, toluene,
Examples include solvents that do not adversely affect the progress of this reaction, such as xylene. In addition, as a polymerization initiator, AIBN, BPO,
Examples include acetyl peroxide. The reaction is preferably carried out in the presence of an inert gas such as nitrogen gas.

Although the reaction temperature is not particularly limited, the reaction is usually carried out at or under heating.

(2) Copolymerization (Vo) 10 Reaction of compound (Via) → silicone resin (■°) Reaction of compound (Vla) with copolymerization compound (Vo) in the presence of an organic solvent and a dehalogenating agent such as triethylamine. let Examples of the organic solvent in this case include THF, chloroform, dichloroethane, and other solvents that do not adversely affect the progress of this reaction.

Silicone resins (■), (■
) and (■°) can be dissolved in an organic solvent such as toluene to adjust the concentration and used as a dental adhesive.

Next, the silicone resin (■) of the present invention.

The use of (■) and (■゛) as dental adhesives will be explained. In this case, the silicone resin of the present invention is used to bond the resin denture base and the silicone rubber lining material, but the lining material is chemically bonded, while the denture base is physically bonded. It is used for adhesion.

(A) When using a silicone resin (■) A condensation type silicone rubber is used as the backing material, and the backing material is cured by a condensation reaction with the adhesive as described below. In the following formula, (■a) represents the tri-lower alkyloxysilane structure of (■) above, and (IX) represents the partial structure of the condensed silicone rubber.

(■a) (IX) R13R11R11R13 R12R+4 [Kari] [In the formula, T I , R2, R3, and R4 have the same meanings as before, R mouth, R+2. R13, R'' means a lower alkyl group] (B) When silicone resin (■) is used, an addition type silicone rubber is used as the backing material, and as shown below, for example, a platinum catalyst (HzPtCla etc.) is used. ), the backing material undergoes an addition reaction with the adhesive and is cured.In the following formula, (■a) represents the vinyldialkylsilane structure of (■) above, and (X) represents the addition type silicone. Shows the partial structure of rubber.

RIG (■a) B19-51-RIIS (X) Rl 6-5i-B l 5 R90 -O-5i-CI(2-C)I, -5i-R"Rlo
Q B19-51-RIQ (Kari) [In the formula, R9 and R" have the same meaning as before, RISR"
R'', RT8 and RIQ are the same or different and mean a lower alkyl group] (C) When silicone resin (■') is used, an addition type silicone rubber is used as the backing material 1.) ,
As described below, the backing material undergoes an addition reaction with the adhesive in the presence of, for example, a platinum-based catalyst (H2PtC1a, etc.) and is cured.

In the following formula, (■a') represents the vinyl dialkylsilane structure described above (■°), and (X) represents the partial structure of the addition type silicone rubber.

B16-5l-RIS RIG Q (■a') R19-5i-818(X) HlB-51-Hls R90 T2-5t-CH2-C)12-5i-R”R100 R19-51-81e1 (Xllll) [ In the formula, R9 and R'' have the same meanings as before, R''R16, R
17, RT8 and RIG are the same or different and mean a lower alkyl group] The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to these embodiments, and it is within the technical scope of the present invention to appropriately modify the design in accordance with the spirit described above and below.

[Example] Example 1 Silicone resin (■) (R1, R2, R3R4,
R? and R8 is a methyl group, T1 is a propylene group) Synthesis of γ-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., hereinafter sometimes referred to as γ-MPTS), ethyl acrylate (hereinafter sometimes referred to as EA), toluene and BPO in the blending ratios of N'o, 1-No, and 3 shown in Table 1 in a glass sealed tube for polymerization, and after purging with nitrogen, the tube was sealed,
The reaction was carried out by heating at 70°C for 40 hours. After distilling off the solvent from the reaction product under reduced pressure, it was dried under reduced pressure at 60°C to obtain a copolymerization product (resin). The yield and yield are shown in the right column of Table 1.

(The following margins are shown below.
As shown in the figure.

In FIG. 4, the proton peak of the -CH5 group on the α-carbon in the γ-MPTS structure is observed at around 1.2 ppm. In addition, the peak of the -(, R2- proton adjacent to the silicon atom is around 0.6 ppm, =S i OCH
The proton peak of s group is 3. Around Sppm, EA again
Proton peaks on the α carbon are observed at around 2.2 ppm. On the other hand, the proton peak of the -CH3 group of the ethoxy group of EA and the proton peak of the -CHs group (+) on the α carbon of the γ-MPTS unit are observed at around 1.2 ppm.

In FIG. 5, the 5t-0 absorption was observed at 1100 cm-', and the C=o and C-0-C absorptions of the ester were observed at 1740 cm-' and 1190 cm-', respectively. From these results, it was confirmed that the polymerization product was a silicone resin (■) having a γ-MPTS structure and an EA tank structure.

Next, the silicone resins No. 1 to No. 013 (■) obtained as above were dissolved in toluene to a concentration of 20% by weight to prepare an adhesive, which was subjected to an adhesion test. .

In the adhesion test, an acrylic rod (polymethyl methacrylate) was used as the resin bed, and commercially available Toshicon Regular (manufactured by Ohkin Kogyo Co., Ltd.) was used as the condensed silicone rubber backing material.

The adhesion test specimen was prepared according to the following procedure.

An acrylic resin rod with a diameter of 8 cm was cut into a length of 3 cm, and the cut surface was finished flat with a lathe. Each backing material was adhered to the cross section of the resin rod using each adhesive. The thickness of the lining material was 1 mm.

A tensile adhesion test was conducted using these specimens. That is, the test pieces were immersed in hot water at 80° C. for 6.12 and 24.48 hours, and the tensile strength of each test piece after immersion in the hot water was measured to determine the adhesive strength. The tensile strength was measured on five specimens for each sample at a tensile speed of 100 mm/min using an Instron type universal testing machine (TOM100OOX, manufactured by Shinko Co., Ltd.).

The results are shown in Figure 1.

As is clear from FIG. 1, the tensile adhesive strength as a whole decreased rapidly about 6 hours after immersion, and then tended to gradually decrease. In addition, the adhesion properties are No. 1, No. 1, and No. 1, in which the number of moles of γ-MPTS is small.

2 was better than No. 3. The degree of polymerization of ordinary silicone rubber used for impression materials is approximately 1000, and N0
When the number of moles of γ-MPTS charged is large as in 03, there are many γ-MPTS units in the polymer, so
During adhesion with silicone rubber, excess trimethoxysilyl groups remain unreacted. Therefore, it is highly hydrophilic,
It is thought that immersion in hot water makes it easier to peel off at the interface.

Furthermore, when the number of trimethoxysilyl groups increases, the storage stability deteriorates due to condensation polymerization. For this reason, the number of moles of γ-MPTS charged is preferably 20% or less.

Example 2 Silicone resin (■) (R1, R7, FtllR9 and R' are methyl groups, Tl is ethylene group) was synthesized in the following two steps (a) and (b).

(a) Compound (IV) (R' is a methyl group, TI is an ethylene group) Ten compounds (Illa) (R' and R8 are methyl groups) - Copolymer compound (V) (R1, R7 and R6 are methyl groups, TI is 2-Hydroxyethyl methacrylate (HEMA).

Methyl methacrylate (MMA), isopropanol, and AIBN were placed in a sealed glass tube for polymerization in the proportions shown in Table 2, the tube was purged with nitrogen, the tube was sealed, and the reaction was heated at 60°C for 3 hours. was distilled off and the reaction product was dissolved in THF.
The copolymer was then precipitated in a large amount of methanol, followed by filtration and drying. The yield and yield are shown in the right column of Table 2.

The 1H-NMR spectrum of the copolymerization product thus obtained is shown in FIG. 6, and the same <IR spectrum is shown in FIG. In FIG. 6, the peak of 10H2-proton adjacent to the oxygen atom in HEMA is observed at around 3.9 ppm. In addition, the proton peak of -OH group was observed at around 3.4 ppm for NO64 measured in deuterated chloroform, and at a different position from the peak of water in DMSO at 3.3 ppm for N005 measured in DMSO-da. It was found around 4.8 ppm. A proton peak of the 10CR group of MMA was observed around 3.5 ppm.

In Figure 7, the ester C=0 and C-0-C
Absorption was observed at 1740 co+-' and 1150 Cm-', and OH absorption was observed at 3550 cm-'. From these results, it was confirmed that the polymerization product had HEMA units and MMA units.

(b) Copolymer compound (V) Ten compound (Vl) (Y is a chlorine atom) - Anti-copolymer compound (V) of silicone resin (■) and triethylamine are dissolved in THF, and further DM
After VC was added dropwise to react, triethylamine hydrochloride was filtered off and the solvent was distilled off to obtain a copolymerization product [silicone resin (■)]. Table 3 shows the raw material composition, copolymerization product yield, and yield.

1' The IH-NMR spectrum of the copolymerization product thus obtained is shown in FIG. 8, and the IR spectrum is shown in FIG. 9. In Figure 8, O, lpp, which did not exist in Figure 6,
proton peak of :ESiCH1 group near m, 6. O
=si-CH=CH near ppm.

A proton peak of the group was newly observed, and the proton peak of the -OH group in HEMA had disappeared. Also the 9th
In the IR spectrum shown in the figure, absorption due to the =CH=CH2 group on the silicon atom, which was not seen in Figure 7, is at 1610c.
newly recognized in l'. From these results, DMVC3
was confirmed to react with the HEMA/MMA copolymer to form a polymer having a vinyl group, that is, a silicone resin (■).

Next, the silicone resin obtained as described above was dissolved in a solvent to prepare an adhesive, which was subjected to an adhesion test between a denture base material resin and a lining material.

The method for preparing the adhesive, the type of resin for the denture base material, the method for preparing the adhesion test specimen, and the tensile adhesion test method for the test specimen are shown in Example 1.
The test was conducted in the same manner as in the above case, but the 80°C hot water immersion time was tested for a period of 0 to 10 mouths.

As the silicone rubber backing material, commercially available tricone addition type regular (manufactured by Sankai Kogyo Co., Ltd.) was used. An adhesion test was also conducted using Toshicon-added Adhesive (manufactured by Sankai Kogyo Co., Ltd.) as an adhesive for comparison.

The results are shown in Figure 2. As is clear from FIG. 2, the tensile strength of the adhesive test specimen using the conventional commercially available adhesive decreased with each passing day after being immersed in hot water. However, the adhesive strength of samples No. 6 and No. 7 was good, and especially the adhesive strength of No. 6 hardly decreased even 10 days after immersion. The reason for this is thought to be that on the silicone rubber side, the vinyl groups in the adhesive polymer reacted and bonded with the addition-type silicone rubber, and on the acrylic resin side, the MMA structure in the adhesive penetrated into the acrylic resin and bonded. It will be done. A schematic diagram of the bonded state assumed in this way is shown in FIG. In FIG. 3, 1 represents an adhesive layer, 2 represents a lining material, and 3 represents a resin (denture base).

In No. 7, the tensile strength slightly decreased due to hot water immersion because of H E M A /MM in Table 2.
Since the proportion of HEMA units in copolymer A (No. 5) is higher than that in N014, there are many hydroxyl groups of HEMA that remain unreacted during the reaction with DMVC3, and this is thought to be due to the large wood-philicity. It will be done.

As shown in Figure 10, the tensile strength of the addition-type silicone rubber itself remained at a constant value for 10 days after being immersed in hot water.
It was confirmed that the addition-type silicone rubber itself has high durability against water.

[Effect of the invention] Since the present invention is configured as described above, RTV and L
TV silicone rubber backing material A new silicone resin that exhibits excellent adhesive properties when used as an adhesive for resin denture bases, has excellent water resistance, and can be used for a long time in the oral cavity. A manufacturing method is provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between hot water immersion time and tensile bond strength of the adhesive for condensation type denture lining materials according to the present invention, and FIG. 2 is a diagram showing the relationship between the adhesive for additive type denture lining materials according to the present invention. A diagram showing the relationship between the number of days immersed in hot water and tensile bond strength in Examples and Conventional Examples, and Figure 3 is a schematic diagram of the bonding mechanism when a denture base and lining material are bonded using the additive adhesive of the present invention. Figure 4 is an NMR spectrum diagram of an example of the present invention, and Figure 5 is an IR spectrum diagram of the same example.
Spectrum diagram, FIG. 6 is an NMR spectrum diagram of an intermediate product in the process of manufacturing the silicone resin of the present invention,
Figure 7 is an IR spectrum diagram of the same, Figure 8 is an NMR spectrum diagram of another example of the present invention, Figure 9 is an IR spectrum diagram of the same, and Figure 10 is an addition type silicone rubber backing used in the implementation of the present invention. It is a figure which shows the tensile test result of a dressing material. l...Adhesive layer 2...Additional silicone rubber backing material 3...Polymethyl methacrylate L (5mi-3 2nd heat)N immersion days (days) 1st Heat 7x immersion time ( hr) Figure 3 Figure 4 ppm (60NiHz, CDC1,a) Figure 6 99m Figure 5 Wave number (CM-1 Figure 7 Wave number [') Figure 8 pI) m Figure 9 Wave number (60,000-1 )

Claims (5)

[Claims] (1) (I) to (III) shown in the following general formula are repeating elements, and each of these repeating elements is an arbitrary combination in any of the following (a), (b), or (c). A silicone resin characterized by an arbitrary number of bonds in a repeating order. (B) (I) and (III) (B) (II) and (III) (C) (II') and (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲Mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II') ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) [In the formula, R^1 and R^7 are the same or different. Hydrogen or lower alkyl group, R^2, R^3, R^4 and R^
8 are the same or different and mean a lower alkyl group, R^5 and R^6 are the same or different and mean a lower alkyl group or a vinyl group, T^1 and T^2 are the same or different and mean a lower alkylene group] (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I a) [In the formula, R^1, R^2, R^3, R^4 and T^1 have the same meaning as before] Tri-lower alkyloxysilane compounds and polymerization initiators have general formulas ▲Mathematical formulas, chemical formulas, tables, etc.▼(IIIa) [In the formula, R^7 and R^8 have the same meanings as before]. By reacting, claim (1)
A method for producing a silicone resin, which comprises producing a copolymer represented by the combination of (a) in (a). (3) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IV) [In the formula, R^1 and T^2 have the same meanings as before] A hydroxy compound represented by a polymerization initiator, ▲ Mathematical formula, chemical formula , tables, etc. ▼ (IIIa) [In the formula, R^7 and R^6 have the same meanings as before] A general formula obtained by reacting an acrylic compound ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (V) [In the formula, R^1, R^7, R^8 and T^2 have the same meanings as before] A copolymer having a hydroxy group represented by the general formula ▲ mathematical formula, chemical formula, table, etc. ▼(VI) [In the formula, R^9 and R^1^0 are the same or different and are a lower alkyl group or a vinyl group, Y means a halogen] By reacting a compound having a halogen represented by A method for producing a silicone resin, which comprises producing a copolymer represented by the combination (b) in claim (1). (4) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IVa) [In the formula, R^1 has the same meaning as before, Z means active ester] An active ester compound represented by the following is combined with a polymerization initiator. , General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (IIIa) [In the formula, R^7 and R^8 have the same meanings as before] General formula obtained by reacting the acrylic compound ▲ Mathematical formula, There are chemical formulas, tables, etc. ▼(V') [In the formula, R^1, R^7, R^8 and Z have the same meanings as before] The general formula ▲Math. , chemical formulas, tables, etc. ▼ (VIa) By reacting the compound represented by [In the formula, R^9, R^1^0 and T^2 have the same meanings as before], the claim (
A method for producing a silicone resin, which comprises producing a copolymer represented by the combination (c) in 1). (5) An adhesive for bonding a room-temperature curing or low-temperature curing silicone rubber lining material to a denture base, (a) If the silicone rubber is a condensation type silicone rubber, the adhesive is The adhesive is a silicone resin represented by (a) in claim (1), and (b) when the silicone rubber is an addition type silicone rubber, the adhesive is a silicone resin represented by (b) or (b) in claim (1).
A dental adhesive characterized by being a silicone resin shown in c).