Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2000-09-07
2004-09-21
Yoon, Tae H. (Department: 1714)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S011000
Reexamination Certificate
active
06794520
ABSTRACT:
The invention relates to silanes based on methylene dithiepane which are suitable in particular for the preparation of dental materials.
Hydrolyzable silanes which contain polymerizable organic radicals are used in the preparation of coatings, particulate fillers, adhesive materials and monolithic moulded bodies as well as in the surface modification of strengthening materials. The silanes are hydrolytically condensed and polymerized, i.e. cured, thermally, photochemically or by redox initiation, alone, mixed with other silanes or in the presence of other metal alkoxides.
It is above all organically modified silanes with polymerizable organic groups such as vinyl, (meth)acryl, allyl or styryl groups that are of particular interest in connection with the preparation of organic-inorganic composite materials as they allow the simultaneous or consecutive construction of both an inorganic and an organic network and thus of composite materials with made-to-measure properties (cf. H. Schmidt, Mat. Res. Soc. Symp. Proc. Vol. 32 (1984), 327-335; H. Schmidt, H. Wolter, J. Non-Cryst. Solids 121 (1990), 428-435). The polymerizable silanes are usually first hydrolytically condensed in solution. After the addition of a thermal initiator or photoinitiator and removal of the solvent, nanoparticulate resins form which are polymerized after shaping and thus cured.
A significant disadvantage of these materials is that the development of the organic network taking place during polymerization is mostly accompanied by a considerable contraction in volume which can lead to the deformation of the moulded bodies, to a reduction in the substrate adhesion, to a separation of the layers, to the development of voids or to the development of material stresses. There is a reduced contraction in volume in the case of silanes which carry ring-opening groups. In this regard, EP 0 358 011 A2 describes scratch-resistant materials inter alia on the basis of 3-glycidyl oxypropyl silanes and EP 0 486 469 A1 organic-inorganic hybrid polymers of 3-glycidyl oxypropyl silanes.
Furthermore, dental materials based on polymerizable silanes are known. DE 36 10 804 A1 discloses dental resin compounds which contain siloxane polymers, monomers which are co-polymerizable with the siloxane polymers and a polymerization catalyst. The dental resin compounds are said to have an improved compression resistance, abrasion resistance and flexural strength after polymerization.
DE 34 07 087 A1 and WO 92/16183 relate to the use of compositions based on organically modified silicic acid polycondensates to coat teeth and dental prostheses. The cured coats are said to be resistant vis-a-vis the build-up of plaque.
Dental resin compounds based on polymerizable polysiloxanes are known from DE 41 33 494, which are obtained by hydrolytic condensation of silanes with 1,4,6-trioxaspiro-[4,4]-nonane radicals. Silanes with orthoester groups are difficult to access and not very storage-stable. In addition, silanes with epoxide or spiroorthoester groups can only be cationically polymerized, which makes it necessary to exclude moisture. In addition, the polymerization of the epoxide silanes proceeds sufficiently quickly only at increased temperatures.
DE 196 19 046 discloses low-shrinkage polymerizable compositions based on mercapto- or norbornene silanes and a reaction partner for en-thiole polymerization.
DE 197 14 320 A1 relates to dental materials based on vinylcyclopropane silanes and DE 197 14 324 A1 to dental materials based on oxetane silanes.
Furthermore, methylene dithiepane group-containing monomers, such as e.g. dimethyldi-[2-(6-methylene-1,4-diethiepane)methoxy]silane (DMTEPS), are known from WO 96/19471, which can be radically polymerized accompanied by ring-opening. DMTEPS contains no hydrolyzable groups which would allow a hydrolytic condensation yielding polysiloxanes. Rather, the dithiepane radicals are split off during the hydrolysis.
The object of the invention is to prepare silanes based on methylene dithiepane, which can be covalently incorporated into organic-inorganic composite materials, can be polymerized rapidly at room temperature and display only a low shrinkage during polymerization.
The object is achieved by silanes according to formula (I) which contain at least one methylene dithiepane group:
R
1
=a saturated or unsaturated aliphatic or alicyclic hydrocarbon radical with 1 to 10 carbon atoms which can be interrupted by one or more oxygen and/or sulphur atoms and can contain one or more ester, carbonyl, amide and/or urethane groups, or an aromatic or heteroaromatic hydrocarbon radical with 6 to 18 carbon atoms and optionally one or more, preferably one or two heteroatoms, preferably S, O and/or N atoms;
R
2
=one of the meanings given for R
1
or is absent;
R
3
=one of the meanings given for R
1
or is absent;
R
4
=—(CHR
6
)
n
—, —Y—CO—NH—(CHR
6
)
n
—, —Y—CO—NH—R
5
—, —(CHR
6
)
n
—S—R
5
—, —S—R
5
—, —CO—O—R
5
— or is absent, where n=1 to 4, R
6
=hydrogen, C
1
to C
10
alkyl or C
6
to C
10
aryl, R
5
has one of the meanings given for R
1
and Y stands for an O— or S— atom or is absent;
X=a hydrolyzable group;
a, b, c and x are 1, 2 or 3 each independently of each other;
with the sum of a+x=2 to 4.
Preferably, b is equal to 1 when a is greater than 1 and a is equal to 1 when b is greater than 1.
The hydrocarbon radicals also include alkylaryl radicals, such as e.g. CH
3
—Ph—, aryl alkylene groups, such as e.g. >CH—Ph, and arylene alkylene radicals, such as e.g. —CH
2
—Ph— or >CH—Ph—CH<, hydrocarbon radicals with C
7
to C
18
C-atoms being preferred.
In the overall description as well as the claims, alkyl is understood to mean linear, branched or cyclic radicals which preferably contain 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms and most preferably 1 to 4 carbon atoms. Special examples of possible alkyl groups are methyl, ethyl, n-propyl, iso-propyl, sec.-butyl, tert.-butyl, n-pentyl, cyclohexyl, 2-ethylhexyl and octadecyl.
Aryl is understood to mean radicals, groups or substituents which preferably have 6 to 10 carbon atoms and can be substituted as given above. Preferred aryl groups are phenyl, biphenyl and naphthyl.
The alkoxy and acyloxy groups are derived from the above-named alkyl and aryl radicals. Special examples are methoxy, ethoxy, n-propyl, isopropyl, tert.-butyloxy, acetyloxy, acetyl, benzyl, 2-phenylethyl and tolyl.
The above-named radicals and groups can be unsubstituted or carry one or more substituents, in particular alkyl, aryl, halogen, preferably chlorine, hydroxy, alkoxy, hydroxyalkyl, carboxy, —SO
3
H, —PO
3
H
2
and/or —PO
4
H
2
.
The ester, carbonyl, amide and urethane groups which are possibly present in the radicals are defined by the following formulae: —CO—O—, —O—CO—, —CO—, —CO—NH—, —NH—CO—, —O—CO—NH—, —NH—CO—O—. The groups can be integrated into the radicals or be terminally bonded thereto.
Preferred definitions, which can be chosen independently of each other, for the individual variables are:
R
1
=a saturated or unsaturated aliphatic or alicyclic hydrocarbon radical with 1 to 8 carbon atoms which can be interrupted by oxygen or sulphur atoms, ester, carbonyl, amide and/or urethane groups, or an aromatic hydrocarbon radical with 6 to 10 carbon atoms; in particular a saturated or unsaturated aliphatic or alicyclic hydrocarbon radical with 1 to 6 carbon atoms or an aromatic hydrocarbon radical with 6 to 10 carbon atoms;
R
2
=a saturated or unsaturated aliphatic or alicyclic hydrocarbon radical with 1 to 8 carbon atoms which can be interrupted by oxygen or sulphur atoms, ester, carbonyl, amide and/or urethane groups, or an aromatic hydrocarbon radical with 6 to 10 carbon atoms; in particular a saturated or unsaturated aliphatic hydrocarbon radical with 1 to 4 carbon atoms which can contain an oxygen atom or an ester group, or is absent;
R
3
=a saturated or unsaturated aliphatic or alicyclic hydrocarbon radical with 1 to 8 carbon atoms which can be interrupted by oxyg
Moszner Norbert
Rheinberger Volker
Stein Sabine
Völkel Thomas
Ivoclar AG
Nixon & Peabody LLP
Yoon Tae H.
LandOfFree
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