Organic compounds -- part of the class 532-570 series – Organic compounds – Carboxylic acid esters
Reexamination Certificate
2002-02-07
2004-01-06
Rotman, Alan L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carboxylic acid esters
C206S063500, C433S222100, C433S228100, C523S116000, C524S559000, C524S560000, C106S035000
Reexamination Certificate
active
06673958
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to a group of novel high molecular weight, multi-acrylate compounds which can be used alone or in conjunction with other compounds and which increase the bonding strength between a dental substrate and a dental composite restorative material, decrease shrinkage in the dental composite material, and which have no toxicity.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention, there is provided a group of novel high molecular weight, multi-acrylate compounds produced by (a) a reaction of unsaturated alcohols with cyclic acid dianhydrides, (b) subsequent reaction of the product of reaction (a) with unsaturated glycidyl ethers, and (c) subsequent reaction of product of reaction (b) with unsaturated isocyanates.
The dianhydrides, which can be used in the invention, are those having the formula:
The unsaturated alcohols useful in the invention are those having the formula:
wherein R
1
is H, CH
3
, or ═CH
2
; R
2
is H or CH
3
; n is 1, 2, 3, or 4; and x is 0 or 1.
The unsaturated glycidyl ethers useful in the invention are those having the formula:
wherein R
1
is H, CH
3
, or ═CH
2
, R
2
is H or CH
3
; n is 1, 2, 3, or 4; and x is 0 or 1.
The unsaturated isocyanates useful in the invention are those having the formula:
wherein R
1
is H, CH
3
, or ═CH
2
; R
2
is H or CH
3
; n is 1, 2, 3, or 4; and x is 0 or 1.
The reaction product produced in this manner is used in accordance with the invention in conjunction with other compounds such as a dentin conditioner or other components of a dental composite material. These materials are applied in solution to an area in which a bond is desired. The bond is usually completed by use with a self-curing initiator or a light cure system.
DETAILED DESCRIPTION OF THE INVENTION
Presently preferred high molecular weight, multifunctional compounds of the present invention are, in general, symmetrical compounds having a polyaromatic nucleus substituted with six acrylate groups. Representative of such preferred high molecular weight, multifunctional compounds of the present invention are those having the following structure:
wherein R
2
is H or CH
3
.
The novel high molecular weight, multi-acrylate compounds are produced by (a) a reaction of unsaturated alcohols with cyclic dianhydrides, (b) subsequent reaction of the product of reaction (a) with unsaturated glycidyl ethers, and (c) subsequent reaction of product of reaction (b) with unsaturated isocyanates.
Presently preferred cyclic dianhydrides useful in the invention are, in general, symmetrical compounds having an aromatic nucleus substituted with four carboxylic acid groups from which two moles of water have been removed to form two cyclic anhydride groupings. Representative of such preferred cyclic dianhydrides, which can be used in the invention, are those having the following structure:
This compound is produced by General Electric Co. under the name Bisphenol A Dianhydride and may be purchased from the Aldrich Chemical Co. under the name of 4,4′-(4,4′-isopropylidenediphenoxy)bis(phthalic anhydride). For producing the novel bonding agent components in accordance with the invention, the cyclic dianhydrides as described above are permitted to react in the presence of a small amount of a tertiary amine such as triethylamine, with preferably at least two molar equivalents of an unsaturated alcohol having the formula II.
The preferred unsaturated alcohols used in making the components of the invention are hydroxyethyl methacrylate and hydroxypropyl methacrylate. When these alcohols are reacted with suitable anhydrides in accordance with the invention, there is produced a group of preferred compounds having the formula:
wherein R
2
is H or CH
3
.
An example of the preparation of an unsaturated alcohol-cyclic dianhydride product is given in the following reaction, in which symmetrical dianhydride (I) is reacted with two moles of hydroxyethyl methacrylate.
The presently preferred product, 4,4′-(4,4′-isopropylidinediphenoxy)bis phthalate methacrylate ester (IDBM, VI) as described above is then permitted to react in the presence of preferably at least two molar equivalents of an unsaturated, glycidyl ether having the formula III.
A preferred unsaturated glycidyl ether used in making the components of the invention is glycidyl methacrylate. When these glycidyl ethers are reacted with products (VI) in accordance with the invention, there is produced a group of preferred compounds having the formula:
wherein R
2
is H or CH
3
.
An example of the preparation of an unsaturated glycidyl ether-benzoate product is given in the following reaction, in which symmetrical benzoate (VII) is reacted with two moles of glycidyl methacrylate.
The products (VIII) as described above are permitted to react in the presence of a small amount of a DBTDL (Dibutyltin dilurate) in dichloromethane, with preferably at least two molar equivalents of an unsaturated isocyanate having the formula IV.
A presently preferred unsaturated isocyanate used in making the components of the invention is isocyanoethyl methacrylate. When these isocyanates are reacted with products (VIII) in accordance with the invention, there is produced a group of preferred compounds having the formula:
wherein R
2
is H or CH
3
.
An example of the preparation of an unsaturated isocyanate-diester product is given in the following reaction, in which symmetrical diester (VIII) is reacted with two moles of isocyanoethyl methacrylate.
The high molecular weight, multifunctional product (V) illustrated in the above reaction may be one component of a novel dental bonding composition in accordance with the invention. The novel dental bonding compositions of the present invention and methods for their use have particular application in the field of restorative dentistry. Preferred compositions according to the present invention comprise a hexafunctional compound V, a filler portion, a polymerization catalyst portion comprising a polymerization compound or system. Optionally, the compositions may also include an additional multifunctional and/or monofunctional comonomer portion, antimicrobial agents, opaquifiers, fluoride-release agents, colorants and other components, which impart desirable properties to the composition. Such additional agents may be incorporated into one or more of the monomer, comonomer or filler portions of the compositions, or may be added in small amounts to the composition during formulation. Hexafunctional compounds V are used to build up a better cross-linking structure in the polymer matrix. This structure plays a very important role in the mechanical properties of the dental materials.
Presently preferred amounts of hexafunctional compound V in compositions of the present invention are from about 3 to about 60 weight percent of the total composition. Presently more preferred amounts are in the range of about 5 to about 20 weight percent of the composition.
Preferred fillers according to the present invention include one or more well-known sub-micron size fillers. For example, sub-micron size fillers are silanated oxides of aluminum, zirconium and silicon, silicate glasses, and barium or strontium glasses. The use of sub-micron size fillers is presently preferred to minimize surface wear and “plucking” of filler components from the restorative surface, as well as imparting a surface which may be easily polished by the dental professional. Preferred contemplated filler particles have an average size of about 0.03 to about 4 microns. Presently more preferred fillers have an average particle size of about 0.04 to about 20 microns. Presently more preferred fillers are of a micron or submicron average particle size of about 0.05 to about 10 microns.
One or more of the aforementioned fillers comprising the filler portion may also include caries inhibiting agents such as slow releasing fluoride agents to help inhibit caries from forming in the adjacent tooth structure. For example, glass ionomer IX 1944 from Ferro Corp
Hamer Martin
Suh Byoung I.
Tiba Amer
Bisco Inc.
Howrey Simon Arnold & White , LLP
Oh Taylor V.
Rotman Alan L.
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