The present invention is related to the use of ethylene alkanoate-alkyl acrylate bipolymers with a high randomness monomers distribution, which are synthesized by semicontinuous emulsion polymerization process, characterized because it is carried out using slow addition rate of the pre-emulsion feeding ({dot over (q)}≤0.009 kg.Math.L.sup.−1.Math.min.sup.−1), stabilized this last one by alkyl glycol ether type surfactants, at temperatures higher than 75° C. and with solids contents above 25 wt %, which avoids the formation of large sequences (blocks) of a same monomer. This structural characteristic gives the ethylene alkanoate-alkyl acrylate bipolymers a high efficiency as chemical agents for removal of complex water/crude oil emulsions of crude oil blends.

The present invention is related to the use of ethylene alkanoate-alkyl acrylate bipolymers with a high randomness monomers distribution, which are synthesized by semicontinuous emulsion polymerization process, characterized because it is carried out using slow addition rate of the pre-emulsion feeding ({dot over (q)}≤0.009 kg.Math.L.sup.−1.Math.min.sup.−1), stabilized this last one by alkyl glycol ether type surfactants, at temperatures higher than 75° C. and with solids contents above 25 wt %, which avoids the formation of large sequences (blocks) of a same monomer. This structural characteristic gives the ethylene alkanoate-alkyl acrylate bipolymers a high efficiency as chemical agents for removal of complex water/crude oil emulsions of crude oil blends.

An acrylic rubber containing: an alkyl acrylate unit; a crosslinking monomer unit; a unit of a bifunctional monomer represented by the following formula (A-1):

##STR00001##

wherein n represents 1 to 9, R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents an alkanediyl group having 2 to 4 carbon atoms; and an ethylene unit, wherein the acrylic rubber has a toluene insoluble content of 4 to 40% by mass.

An acrylic rubber containing: an alkyl acrylate unit; a crosslinking monomer unit; a unit of a bifunctional monomer represented by the following formula (A-1):

##STR00001##

wherein n represents 1 to 9, R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents an alkanediyl group having 2 to 4 carbon atoms; and an ethylene unit, wherein the acrylic rubber has a toluene insoluble content of 4 to 40% by mass.

Provided herein are curable compositions for use in a high temperature lithography-based photopolymerization process, and telechelic block polymers and methods of using such polymers in curable compositions to produce medical devices such as orthodontic appliances comprising the polymeric compositions comprising the telechelic block polymers.

Provided herein are curable compositions for use in a high temperature lithography-based photopolymerization process, and telechelic block polymers and methods of using such polymers in curable compositions to produce medical devices such as orthodontic appliances comprising the polymeric compositions comprising the telechelic block polymers.

Orthodontic articles and polymerizable resin compositions are described. The orthodontic article comprises a cured composition comprising the reaction product of free-radically polymerizable resin comprising 30 to 70 wt. %, inclusive, of at least one urethane component, and 25 to 70 wt. %, inclusive, of reactive diluent(s) comprising at least one monofunctional (meth)acrylate monomer. The polymerizable resin comprises no greater than 35 wt. % of reactive diluent(s) having a high affinity for water. Reactive diluent(s) such as monofunctional (meth)acrylate monomers having a high affinity for water have low log P values. In one embodiment, the polymerizable resin comprises at least one acidic monomer.

Orthodontic articles and polymerizable resin compositions are described. The orthodontic article comprises a cured composition comprising the reaction product of free-radically polymerizable resin comprising 30 to 70 wt. %, inclusive, of at least one urethane component, and 25 to 70 wt. %, inclusive, of reactive diluent(s) comprising at least one monofunctional (meth)acrylate monomer. The polymerizable resin comprises no greater than 35 wt. % of reactive diluent(s) having a high affinity for water. Reactive diluent(s) such as monofunctional (meth)acrylate monomers having a high affinity for water have low log P values. In one embodiment, the polymerizable resin comprises at least one acidic monomer.

The block copolymer intermediate represented by the following general formula (1) or (2) is used. In the formulae, R.sup.1 and R.sup.7 each independently represent a polymerization initiator residue, R.sup.2 and R.sup.8 each independently represent an aromatic group or an alkyl group, Y.sup.1 represents a polymer block of (meth)acrylic ester: Y.sup.2 represents a polymer block of styrene or a derivative thereof, and m and n each independently represent in an integer from 1 to 5. In the formulae, R.sup.3 represents an alkylene group having 1 to 6 carbon atoms, L represents a linking group, R.sup.4 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group, and R.sup.5 and R.sup.6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

##STR00001##

The block copolymer intermediate represented by the following general formula (1) or (2) is used. In the formulae, R.sup.1 and R.sup.7 each independently represent a polymerization initiator residue, R.sup.2 and R.sup.8 each independently represent an aromatic group or an alkyl group, Y.sup.1 represents a polymer block of (meth)acrylic ester: Y.sup.2 represents a polymer block of styrene or a derivative thereof, and m and n each independently represent in an integer from 1 to 5. In the formulae, R.sup.3 represents an alkylene group having 1 to 6 carbon atoms, L represents a linking group, R.sup.4 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group, and R.sup.5 and R.sup.6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

##STR00001##