Crosslinkable and crosslinked polymeric materials
View Patent ↗Crosslinkable compositions are provided that contain a) a polymeric material having at least two terminal dithiocarbamate groups or two terminal dithiocarbonate groups and b) a monomer composition that includes at least a crosslinking monomer having two or more ethylenically unsaturated groups. The polymeric materials in the crosslinkable compositions undergo chain extension and crosslinking reactions when exposed to actinic radiation in the ultraviolet region of the electromagnetic spectrum. Additionally, crosslinked compositions, articles that contain the crosslinkable compositions or the crosslinked compositions, and methods of making the articles are provided.
1. A crosslinkable composition comprising:
a) a polymeric material of Formula (I)
wherein
R 1 is hydrogen, alkyl, fluorinated alkyl, aryl, aralkyl, or substituted aryl;
X is oxy or—NR 2 — where group R 2 is hydrogen, alkyl, fluorinated alkyl, aryl, aralkyl, or substituted aryl;
each R 3 is an alkoxy, fluorinated alkoxy, or —N(R 4 ) 2 where each R 4 is an alkyl, fluorinated alkyl, or together with the nitrogen to which they are both attached form a heterocyclic ring;
each P is a polymeric block that comprises a polymerized product of a first monomer composition comprising at least one monomer having a single ethylenically unsaturated group;
y is an integer in a range of 1 to 5; and
b) a second monomer composition that is miscible with the polymeric material of Formula (I), the second monomer composition comprising a crosslinking monomer having at least two ethylenically unsaturated groups.
2. The crosslinkable composition of claim 1 , wherein y is equal to 1 and the polymeric material of Formula (I) is an elastomeric material.
3. The crosslinkable composition of claim 1 , wherein the crosslinkable composition comprises 5 to 99.99 weight percent polymeric material of Formula (I), 0.01 to 20 weight percent crosslinking monomer having at least two ethylenically unsaturated groups, and 2) 0 to 95 weight percent monomer having a single ethylenically unsaturated group, wherein each amount is based on a total weight of polymerized and polymerizable material.
4. The crosslinkable composition of claim 1 , wherein the polymeric material of Formula (I) has a weight average molecular weight in a range of 10,000 Daltons to 5 million Daltons.
5. The crosslinkable composition of claim 1 , wherein the crosslinkable composition further comprises a photoinitiator.
6. The crosslinkable composition of claim 5 , wherein the photoinitiator is of Formula (V)
wherein
R 1 i is hydrogen, alkyl, fluorinated alkyl, aryl, aralkyl, or substituted aryl;
X is oxy or —NR 2 — where group R 2 is hydrogen, alkyl, fluorinated alkyl, aryl, aralkyl, or substituted aryl;
each R 3 is an alkoxy, fluorinated alkoxy, or —N(R 4 ) 2 where each R 4 is an alkyl, fluorinated alkyl, or together with the nitrogen to which they are both attached form a heterocyclic ring.
7. The crosslinkable composition of claim 5 , wherein the photoinitiator is not of Formula (V).
8. The crosslinkable composition of claim 1 , wherein the crosslinking monomer has two or more (meth)acryloyl groups.
9. A crosslinked composition comprising the polymerized product of a crosslinkable composition of claim 1 .
10. The crosslinked composition of claim 9 , wherein the crosslinked composition further comprises a tackifier.
11. The crosslinked composition of claim 9 , wherein the crosslinked composition is a pressure-sensitive adhesive composition.
12. An article comprising:
a first substrate; and
a crosslinked composition layer positioned adjacent to the first substrate, the crosslinked composition layer comprising the crosslinked composition of claim 9 .
13. A method of making an article, the method comprising:
providing a first substrate;
applying a crosslinkable composition layer adjacent to the substrate, the crosslinkable composition layer comprising the crosslinkable composition of claim 1 ;
exposing the crosslinkable composition layer to actinic radiation to form a crosslinked composition layer, wherein the actinic radiation comprises ultraviolet radiation.
14. The method of claim 13 , wherein the substrate is in the form of a polymeric web.
15. The method of claim 13 , wherein the actinic radiation is from a light emitting diode.