Composition containing aziridino groups, method of production and use thereof
The invention relates to a composition comprising a prepolymer as component (A), wherein the prepolymer comprises aziridino groups and is characterized by an equivalent weight EW1, a crosslinker as component (B), wherein the crosslinker has a structure being different from the structure of the prepolymer and comprises at least three 2-alkyl-substituted aziridino groups and is characterized by an equivalent weight EW2, an initiator as component (C) being able to start curing of the composition, optionally filler(s) as component (D) and optionally additive(s) as component (E), wherein equivalent weight is defined as (molecular mass of the molecule)/(number of aziridino groups present in the molecule) and wherein EW1>EW2. The invention also relates to the use of the composition for coating, sealing, molding, adhering, making impressions, producing a dental material.
1. A composition comprising
a) a prepolymer as component (A), wherein the prepolymer comprises aziridino groups, but not silicone moieties, and is characterized by an equivalent weight EW1,
b) a crosslinker as component (B), wherein the crosslinker has a molecular structure being different from the molecular structure of the prepolymer and comprises at least three 2-alkyl-substituted aziridino groups and is characterized by an equivalent weight EW2, and
c) an initiator as component (C) being able to start curing of the composition, wherein equivalent weight is defined as the molecular mass of the molecule divided by the number of aziridino groups present in the molecule, and wherein EW1>EW2.
2. The composition of claim 1 , further comprises a filler as component (D).
3. The composition of claim 2 , further comprising an additive as component (E).
4. The composition according to claim 1 , wherein the prepolymer has a molecular weight (Mn) within the range of about 3,000 to about 12,000 and the crosslinker has a molecular weight (Mn) within the range of about 400 to about 5,000.
5. The composition according to claim 1 , wherein the composition satisfies at least one of the following parameters after curing:
a) a shore hardness A (DIN 53505) of at least 40 after 24 h,
b) a tensile strength (DIN 53504) of at least 1.6 MPa, and/or
c) an elongation at break (DIN 53504) of at least 180%.
6. The composition according to claim 3 comprising
a) Component (A) in an amount of about 10 wt.-% to about 90 wt.-%,
b) Component (B) in an amount of about 0.1 wt.-% to about 20 wt.-%,
c) Component (C) in an amount of about 1 wt.-% to about 30 wt.-%,
d) Component (D) in an amount of about 0 wt.-% to about 80 wt.-%,
e) Component (E) in an amount of about 0 wt.-% to about 50 wt.-%
with respect to the whole composition.
7. The composition according to claim 1 , wherein the prepolymer is characterized by at least one of the following features:
a) a molecular weight (Mn) in the range of about 3,000 to about 30,000,
b) a linear molecular structure of the backbone,
c) at least about 2 aziridino groups, and/or
d) an equivalent weight (EW1) of at least 1000.
8. The composition according to claim 1 , wherein the prepolymer comprises polyether, polyurethane and/or polyester groups.
9. The composition according to claim 1 , wherein the crosslinker is characterized by at least one of the following features:
a) a molecular weight (Mn) in the range of about 200 to about 10,000
b) a branched molecular structure of the backbone,
c) at least three 2-alkyl-substituted aziridino groups; and/or
d) an equivalent weight (EW2) of about 100.
10. The composition according to claim 1 , wherein the crosslinker has one of the following structures:
11. The composition according to claim 2 , wherein component (D) comprises one or more fillers selected from the group consisting of reinforcing and non-reinforcing fillers.
12. The composition according to claim 3 , wherein component (E) comprises one or more additives selected from the group consisting of dyes, pigments, thixotropic agents, flow improvers, polymeric thickeners, surfactants, odorous substances, diluting agents and flavourings.