Polymeric compositions prepared with a controlled radical initiator
Crosslinkable polymeric materials, crosslinked polymeric materials, articles containing the crosslinkable polymeric materials or crosslinked polymeric materials, and methods of making the articles and various compositions are provided. More particularly, the crosslinkable composition contains a) a first polymeric material, which has terminal dithiocarbamate or dithiocarbonate groups, b) a crosslinking composition containing a chlorinated triazine crosslinking agent and/or a crosslinking monomer having two or more ethylenically unsaturated groups, and c) a thixotropic agent containing metal oxide particles. The crosslinkable composition may be printable or dispensed. In some embodiments, the crosslinked composition is a pressure-sensitive adhesive.
1. A crosslinkable composition comprising:
a) a first polymeric material of Formula (II)
wherein
(P) 1 refers to one polymeric group and (P) 0-1 refers to 0 or 1 polymeric groups, wherein each polymeric group P is a polymeric group comprises a polymerized product of a first monomer composition comprising a first monomer having a single ethylenically unsaturated group;
each R 1 an alkoxy, alkaryloxy, alkenoxy, or N(R 4 ) 2 ;
R 2 is a group of formula (OR 5 ) q —OR 6 or a group of formula —(CO)—X—R 7 ;
R 3 is hydrogen, alkyl, aryl, substituted aryl, alkaryl, a group of formula —(CO)—OR 8 , or a group of formula —(CO)—N(R 9 ) 2 ;
each R 4 is an alkyl or two adjacent R 4 groups are combined with the nitrogen to which they are both attached to form a first heterocyclic ring having 1 to 3 heteroatoms selected from nitrogen, oxygen, and sulfur, the first heterocyclic ring being saturated or unsaturated and optionally fused to one or more second rings that are carbocyclic or heterocyclic;
R 5 is an alkylene;
R 6 is an alkyl;
R 7 is hydrogen, alkyl, aryl, substituted aryl, or aralkyl;
R 8 is an alkyl, aryl, aralkyl, or alkaryl;
R 9 is an alkyl, aryl, aralkyl, or alkaryl;
R 10 is hydrogen, alkyl, aryl, aralkyl, or alkaryl;
X is a single bond, oxy, or —NR 10 —;
q is an integer equal to at least 0;
b) a crosslinking composition, wherein the crosslinking composition is miscible with the polymeric material of Formula (II) and comprises a chlorinated triazine crosslinking agent and/or a crosslinking monomer having at least two ethylenically unsaturated groups; and
c) a thixotropic agent comprising a metal oxide particle.
2. The crosslinkable composition of claim 1 , wherein the weight average molecular weight of the polymeric material of Formula (II) is in a range of 5,000 Daltons to 500,000 Daltons.
3. The crosslinkable composition of claim 1 , wherein the crosslinkable composition comprises 5 to 90 weight percent polymeric material of Formula (II) and a crosslinking composition comprising 1) 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, each amount being based on a total weight of polymerized material and polymerizable material.
4. The crosslinkable composition of claim 1 , wherein the crosslinkable composition comprises 5 to 40 weight percent polymeric material of Formula (II) and a crosslinking composition comprising 1) 0.01 to 10 weight percent crosslinking monomer having at least two ethylenically unsaturated groups and/or chlorinated triazine crosslinking agent and 2) 50 to 95 weight percent monomers having a single ethylenically unsaturated group.
5. The crosslinkable composition of claim 1 , wherein the thixotropic agent comprises silica particles optionally treated with a surface modifying agent.
6. The crosslinkable composition of claim 5 , wherein the surface modifying agent is a silane compound having at least one alkoxy group and at least one alkyl group.
7. The crosslinkable composition of claim 1 , wherein the thixotropic agent is present in an amount in a range of 1 to 10 weight percent based on the total weight of polymerized material and polymerizable material.
8. The crosslinkable composition of claim 1 , wherein the crosslinkable composition further comprises a Type I photoinitiator.
9. The crosslinkable composition of claim 1 , wherein the crosslinkable composition has a Trouton's ratio in a range of 3 to 25 with an extensional rate of 1000 sec −1 .
10. The crosslinkable composition of claim 1 , wherein the crosslinkable composition is printable or dispensable.
11. A crosslinked composition comprising a polymerized product of the crosslinkable composition of claim 1 .
12. The crosslinked composition of claim 11 , wherein the crosslinked composition is a pressure-sensitive adhesive.
13. An article comprising:
a) a substrate; and
b) the crosslinked composition of claim 11 adjacent to the substrate.
14. The article of claim 13 , wherein the crosslinked composition is a pressure-sensitive adhesive.
15. The article of claim 13 , wherein the crosslinked composition is in the form of a continuous layer or in the form of a pattern.
16. The article of claim 13 , wherein the crosslinked composition is a pressure-sensitive adhesive, the substrate is a release liner, and the article is an adhesive transfer tape.
17. The article of claim 14 , wherein the substrate is a release liner and wherein the pressure-sensitive adhesive layer has a first major surface adjacent to the release liner and a second major surface opposite the release liner, the first major surface having a peel strength within 30 percent of a peel strength of the second major surface.