Radically polymerizable compound

Abstract

The invention provides a radically polymerizable compound wherein an acid group is joined via a spacer group to a polyethyleneimine group. The polyethyleneimine group has at least one radically polymerizable group in the side chain and/or terminally. The invention relates further to a process for preparing such compounds by cationic polymerization of oxazolines, to the use of such compounds as constituents of a dental material, and to a dental material comprising the compounds of the invention.

Claims

1. A radically polymerizable compound of the formula I:
(SG).sub.xA((PEI)TG).sub.m where SG=COOR.sup.1, SO.sub.3R.sup.1, OPO.sub.3R.sup.1.sub.2, or PO.sub.3R.sup.1.sub.2; R.sup.1=independently at each occurrence H, C.sub.1-C.sub.7 alkyl, or monovalent cation; x=1-60; A: hydrocarbon group having 1 to 30 carbon atoms and possibly containing silicon, halogen, nitrogen, phosphorus, oxygen, and sulfur; ##STR00008## SKH, C.sub.1-C.sub.20 alkyl, aryl, alkyl-aryl, (CO)NR.sup.3R.sup.4, (CS)NR.sup.3R.sup.4, (CO)OR.sup.3, (CO)R.sup.3, or (SO.sub.2)R.sup.3; R.sup.3, R.sup.4=independently at each occurrence H, alkyl, aryl and/or alkyl-aryl, which may contain halogen, nitrogen, phosphorus, oxygen, and sulfur, or alkenyl; n=2-100; TG=H, NR.sup.6R.sup.7, OR.sup.6, SR.sup.6, cycloalkenes, CR.sup.6R.sup.7R.sup.8, OCOR.sup.9, or NR.sup.6COR.sup.9; R.sup.6, R.sup.7, R.sup.8H, C.sub.1 to C.sub.20 alkyl, aryl and/or alkyl-aryl, which may contain halogen, nitrogen, phosphorus, oxygen, and sulfur; a radically polymerizable group which may contain halogen, nitrogen, phosphorus, oxygen, and sulfur; where R.sup.6 and R.sup.7, with inclusion of the nitrogen atom, may form a ring having 5 to 7 ring atoms and possibly containing heteroatoms; R.sup.9=alkyl, aryl, alkyl-aryl, or alkenyl; where PEI or TG comprises at least one radically polymerizable group; m=1, 2, or 3.

2. The compound as claimed in claim 1, wherein SG is selected from the group consisting of OP.sub.3R.sup.1.sub.2 or PO.sub.3R.sup.1.sub.2.

3. The compound as claimed in claim 1, wherein A is an alkylene or aryl-alkylene or alkyl-arylene group.

4. The compound as claimed in claim 1, wherein at least 50% of SKs are selected from the group consisting of (SO.sub.2)R.sup.3 and (CO)R.sup.3.

5. The compound as claimed in claim 1, wherein R.sup.3 and R.sup.4 are selected from the group consisting of C.sub.1 to C.sub.19 alkyl, and C.sub.2-C.sub.19 alkenyl.

6. The compound as claimed in claim 1, wherein SK has no acid group SG.

7. The compound as claimed in claim 3 of the formula II: ##STR00009## where x=1 or 2; z=2 to 14.

8. The compound as claimed in claim 3 of the formula III: ##STR00010## where x=1 or 2; z=2 to 14.

9. A process for preparing a compound as claimed in claim 1, which comprises cationic polymerization of oxazolines.

10. The process as claimed in claim 9, wherein the cationic polymerization is followed by hydrolysis of the resultant polyoxazoline.

11. The process as claimed in claim 9, wherein the acid group SG is incorporated via the polymerization initiator of the cationic polymerization; and wherein the end group(s) TG is/are incorporated via the termination compound of the cationic polymerization.

12. The process as claimed in claim 9, wherein the end group(s) TG is/are incorporated via the polymerization initiator of the cationic polymerization; and wherein the acid group SG is incorporated via the termination compound of the cationic polymerization.

13. A radically polymerizable dental material comprising as a constituent a compound as claimed in claim 1.

14. A dental material which comprises: a) at least one compound as claimed in claim 1; b) at least one monomer radically copolymerizable with a); c) at least one initiator for the radical polymerization; d) optionally solvents; e) optionally fillers; f) customary dental additives.

15. The dental material as claimed in claim 14, wherein the fraction of the components as a proportion of the total mass is as follows: component a): 1-50 wt %; component b): 5-99 wt %; component c): 0.01-10 wt %; component d): at least 0.1 wt %; not more than 80 wt %; component e): 0-90 wt %.

16. A method of promoting adhesion between a mineral surface and radically polymerizable materials comprising applying a compound as claimed in claim 1 to a mineral surface as an adhesion promoter.

Description

PREPARATION EXAMPLES

I) Preparation of Electrophilic Starter Compounds for the Cationic Polymerization of 2-ethyl-2-oxazoline

(1) Starter compound A (tetraethyl 11-bromoundecanebisphos-phonate

(2) Under nitrogen, 1.4 g of sodium hydride (60% in mineral oil, 35 mmol) was suspended in 15 ml of dry tetrahydrofuran (THF). The suspension was cooled down to 0-5 C. in an ice bath and 8.5 g (30 mmol) of tetraethyl methylenebisphosphonate were added dropwise. 44.4 g (148 mmol) of 1,10-dibromodecane were dissolved in 40 ml of dry THF and added to the reaction mixture. The solution was stirred at RT for 72 h and then admixed with 30 ml of aqueous sodium hydrogencarbonate solution (0.1 mol/1). The THF was then removed on a rotary evaporator and the aqueous phase was extracted by shaking 2 with toluene. The combined organic phases were concentrated on a rotary evaporator. The excess dibromodecane was then removed in a column filtration (SiO2: 1.sup.st eluent: heptane/ethyl acetate 1:1, v/v; 2.sup.nd eluent: ethanol). The crude product was purified with the aid of flash chromatography (SiO2; ethyl acetate/ethanol, 95:5, v/v). This gave a yellowish oil (yield: 65%).

(3) 1H NMR (CDCl3, 300 MHz): =1.20-1.38 (m, 10H, CH2), 1.34 (5, 12H, CH3), 1.38-1.48 (m, 2H, CH2), 1.48-1.62 (m, 2H, CH2), 1.72-2.02 (m, 4H, CH2), 2.27 (tt, 1H, CH), 3.41 (t, 2H, CH2Br), 4.03-4.26 (m, 8H, POCH2).

Starter Compound B (tetraethyl 1,13-di-bromotridecane-7,7-bisphosphonate)

(4) Under nitrogen, 1.6 g of sodium hydride (60% in mineral oil, 40 mmol) was suspended in 10 ml of dry tetrahydrofuran (THF). The suspension was cooled down to 0-5 C. in an ice bath and 4.7 g (16 mmol) of tetraethyl methylenebisphosphate were added dropwise. 40 g (164 mmol) of 1,6-dibromohexane were dissolved in 25 ml of dry THF and added to the reaction mixture. The solution was stirred at RT for 72 h and then admixed with 20 ml of aqueous sodium hydrogencarbonate solution (0.1 mol/1). Subsequent treatment took place in analogy to starter compound A. This gave a yellowish oil (yield: 21%).

(5) 1H NMR (CDCl3, 300 MHz): =1.20-1.38 (m, 4H, CH2), 1.34 (t, 12H, CH3), 1.40-1.62 (m, 8H, CH2), 1.72-2.02 (m, 8H, CH2), 3.41 (t, 4H, CH2Br), 4.03-4.26 (m, 8H, POCH2).

II) Cationic Polymerization of 2-ethyl-2-oxazoline

(6) Under nitrogen, freshly distilled 2-ethyl-2-oxazoline and the respective starter compound, according to table 1, were dissolved in 10 or 15 ml of dry acetonitrile. The solutions were polymerized at 140 C. under pressure in a synthesis microwave (CEM Discovery; microwave power: 100 W) for 10 min.

III) Termination of Cationic Polymerization by Nucleophilic Compounds

III.1) Termination with Amine

(7) After cooling had taken place, n-propylamine was added in a large excess (based on the initiator) to the polymer solution, which was then boiled under nitrogen and under reflux at 70 C. for 24 h. It was subsequently concentrated on a rotary evaporator and the residue was taken up in 10 or 15 ml of dichloromethane. The dichloromethane solution was extracted by shaking first with 10 ml of sodium hydrogencarbonate solution (c(NaHCO3)=1 mol/l, then with 10 ml of water. The organic phase was concentrated on a rotary evaporator and then the residue was again taken up with a little acetonitrile. The solution was subsequently precipitated from cold ether. The precipitation was repeated 2. The precipitated white solid was dried under a high vacuum.

III.2) Termination with Aqueous Potassium Carbonate Solution

(8) After cooling had taken place, 10 ml of potassium carbonate solution (c=10% by weight) were added to the polymer solution which was then boiled under reflux at 100 C. for 10 h. Subsequent treatment took place in analogy to III.1.

IV) Hydrolysis of poly(2-ethyl-2-oxazoline) to polyethyleneimine

(9) Portions of 4 g of polymer powder were boiled with 100 ml of half-concentrated hydrochloric acid under reflux for 24 h. The hydrochloric acid was then distilled off under reduced pressure and the residue was twice washed with methanol and filtered. The filter residue was dried under a high vacuum. This gave a white solid.

V) Derivatization of Polyethyleneimine

V.1) Derivatization with Acryloyl Chloride

(10) Portions of 1 g of a poly(ethyleneimine)alkanebis-phosphonic acid were admixed with 5 ml of water and adjusted with NaOH solution to a pH of 9. After the solution had cooled to 0-5 C., two-thirds of the amount of acryloyl chloride indicated in table 1 were added over the course of 30 minutes. Thereafter the solution was warmed to RT and stirred for 3 h. The solution was subsequently adjusted to a pH of 11-12, again cooled to 0-5 C., and one-third of the amount of acryloyl chloride indicated in table 1 was added. After 3 h of stirring at RT, the solution was adjusted to a pH of 1-2 with concentrated hydrochloric acid. The aqueous solution was stabilized with MEHQ, concentrated, and dried under a high vacuum. The residue was taken up with ethanol, the solution was filtered, and the filtrate was concentrated. The solid obtained during concentration was subsequently suspended in diethyl ether, the suspension was filtered, and the residue was dried under a high vacuum. This gave a white solid.

V.2) Derivatization with Acryloyl Chloride and Decanoyl Chloride

(11) Portions of 1 g of a poly(ethyleneimine)alkanebis-phosphonic acid were admixed with 5 ml of water and adjusted with NaOH solution to a pH of 9. After the solution had cooled to 0-5 C., two-thirds of the amount of acryloyl chloride indicated in table 1 were added over the course of 30 minutes. Thereafter the solution was warmed to RT and stirred for 3 h. The solution was subsequently adjusted to a pH of 11-12, again cooled to 0-5 C., and the amount of decanoyl chloride indicated in table 1 was added. After the end of the addition, the solution was warmed to RT and stirred for 3 h. Subsequently, the solution, at a pH of 11-12, was again cooled to 0-5 C. and one-third of the amount of acryloyl chloride indicated in table 1 was added. After 3 h of stirring at RT, the solution was adjusted to a pH of 1-2 with concentrated hydrochloric acid. The aqueous solution was stabilized with MEHQ, concentrated, and dried under a HV. The residue was taken up with ethanol, the solution was filtered, and the filtrate was concentrated. The solid obtained during concentration was subsequently suspended in diethyl ether, the suspension was filtered, and the residue was dried under a high vacuum. This gave a white solid.

(12) The following compounds (for p and r see table 2) were obtained:

(13) ##STR00005##

Examples 1, 2, 3

(14) 1H NMR (D2O, 300 MHz: =0.85-0.95 (3H, CH3), 1.18-1.38 (12H, CH2), 1.45-1.95 (8H, CH2), 2.05-2.35 (1H, CHP), 2.6-4.2 (4H, CONCH2), 5.60-5.95 (1H, CH2CH), 5.95-6.27 (1H, CH2CH), 6.27-6.80 (1H, CH2CH).

(15) ##STR00006##

Example 5

(16) 1H NMR (D2O, 300 MHz): =1.20-1.50 (12H, CH2), 1.50-1.65 (2H, CH2), 1.65-2.00 (4H, CH2), 2.10-2.40 (1H, CHP), 2.6-4.2 (4H, CONCH2), 5.70-6.00 (1H, CH2CH), 6.00-6.35 (1H, CH2CH), 6.35-6.80 (1H, CH2CH).

Example 6

(17) 1H NMR (DMSO, 300 MHz): =0.86 (3H, CH3), 1.15-1.38 (24H, CH2), 1.38-1.60 (6H, CH2), 1.60-1.80 (2H, CH2), 2.10-2.40 (2H, COCH2), 2.8-4.3 (4H, CONCH2), 5.55-5.80 (1H, CH2CH), 6.0-6.30 (1H, CH2CH), 6.45-6.90 (1H, CH2CH).

(18) ##STR00007##

Example 4

(19) 1H NMR (D2O, 300 MHz): =0.85-0.95 (6H, CH3), 1.1-1.95 (24H, CH2), 2.6-4.2 (8H, CONCH2), 5.6-5.95 (2H, CH2CH), 5.98-6.27 (2H, CH2CH), 6.30-6.80 (2H, CH2CH).

(20) TABLE-US-00001 TABLE 1 Derivatization Starter Oxazoline Termination Yield Derivatization compound Ex. Starter [mmol] [mmol] Compound n.sub.th [wt %] n.sub.NMR compound [mmol] 1 A 3.9 18.5 n-propyl- 5 70 5 acryloyl 6 amine chloride 2 A 3.9 39 n-propyl- 10 70 7 acryloyl 12 amine chloride 3 A 3.9 78 n-propyl- 20 52 14 acryloyl 24 amine chloride 4 B 1.2 24 n-propyl- 10 37 8 acryloyl 24 amine chloride 5 A 3.9 39 OH.sup. 10 67 10 acryloyl 12 chloride 6 A 3.9 39 OH.sup. 10 67 10 acryloyl 6 chloride decanoyl 4 chloride

(21) TABLE-US-00002 TABLE 2 Ex. SG x A n.sub.PEI SK p* r* TG m 1 PO(OH).sub.2 2 CH(CH.sub.2).sub.10 5 COCHCH.sub.2 5 N (CH.sub.2CH.sub.2CH.sub.3) 1 (COCHCH.sub.2) 2 PO(OH).sub.2 2 CH(CH.sub.2).sub.10 10 COCHCH.sub.2 10 N (CH.sub.2CH.sub.2CH.sub.3) 1 (COCHCH.sub.2) 3 PO(OH).sub.2 2 CH(CH.sub.2).sub.10 20 COCHCH.sub.2 20 N (CH.sub.2CH.sub.2CH.sub.3) 1 (COCHCH.sub.2) 4 PO(OH).sub.2 2 (CH.sub.2).sub.6C(CH.sub.2).sub.6 10 COCHCH.sub.2 10 N (CH.sub.2CH.sub.2CH.sub.3) 2 (COCHCH.sub.2) 5 PO(OH).sub.2 2 CH(CH.sub.2).sub.10 10 COCHCH.sub.2 10 OCOCHCH.sub.2 1 6 PO(OH).sub.2 2 CH(CH.sub.2).sub.10 10 COCHCH.sub.2/CO 5 5 OCOCHCH.sub.2 1 (CH.sub.2).sub.8CH.sub.3 *n = p + r

(22) In the subsequent examples, dental materials of the invention are produced and their adhesion properties are tested using light-curing dental adhesives. For this purpose the shear bond strength (SBS) on dental enamel was ascertained.

(23) For the production of the light-curing dental adhesives, their individual components were mixed by stirring at room temperature, in the absence of light that initiates photopolymerization, until a homogeneous solution was formed.

(24) In order to determine the shear bond strength (SBS), bovine incisors without pulp were embedded into a cold-polymerizing resin (Viscovoss GTS with MEKP MEH hardener; Voss Chemie). Immediately before use, the embedded teeth were sanded down wet to the enamel (P120 sandpaper) and then reground wet with a fine sandpaper (P500). Prior to being used, the teeth were stored in demineralized water. For measurement, the teeth were taken from the demineralized water and the moisture was removed from the ground surface using oil-free compressed air. The adhesion promoter was applied with a microbrush and rubbed in for 10 s. After an exposure time of 20 s, the solvents were carefully blown away and the surface was exposed for 10 s to a dental lamp (MiniLED, ACTEON Germany, Mettmann, Germany).

(25) Thereafter a two-part Teflon mold with a hole of 3.0 mm in diameter (ISO/TS 11405:2003) was mounted, and was fixed with a metal bracket, and the cavity was filled with a dental composite (Ecusit, DMG, Hamburg, Germany) and exposed for 40 s (MiniLED). After curing had taken place, the Teflon mold was removed and protruding residues of the cured adhesion promoter were removed using a scalpel. The test specimens prepared were stored at 37 C. for 23 h and at 23 C. for 1 h. The test specimens were then subjected to measurement with a shearing apparatus according to ISO10477:2004 and in an apparatus for determining a force-distance diagram (Z010/TN2A, Zwick GmbH & Co., Ulm, Germany) with a rate of advance of 0.5 mm/min. The result is reported in the form of a mean value with standard deviation. The testing was carried out on 10 test specimens in each case.

(26) TABLE-US-00003 TABLE 3 Compositions of the light-curing dental adhesives and the shear bond strength (SBS) results Composition 1 Composition 2 [wt %] [wt %] Ex. 2 10.6 0 Ex. 5 0 10.6 BisGMA 24.8 24.8 HEMA 29.6 29.6 Ethanol 19.8 19.8 Water 13 13 CQ 0.8 0.8 EHA 1.4 1.4 BHT 0.01 0.01 SBS [MPa] 12.1 3.6 16.5 6.8 BisGMA = bisphenol A diglycidyl dimethacrylate; HEMA = 2-hydroxyethyl methacrylate; CQ = camphorquinone; EHA = 2-ethylhexyl 4-(dimethylamino)benzoate; BHT = 3,5-di-tert-butyl-4-hydroxytoluene