In one preferred embodiment, polymers are provided that comprise a structure of the following Formula (I): ##STR00001##
Photoresists that comprises such polymers also are provided.

Methods for the synthesis of methyl 2-fluoroacrylate (MFA) are provided. The methods include use of various hydrofluorination agents using a variety of starting materials and reaction schemes. The methyl 2-fluoroacrylate prepared by the methods described herein can further be used to prepare patiromer calcium sorbitex.

Methods for the synthesis of methyl 2-fluoroacrylate (MFA) are provided. The methods include use of various hydrofluorination agents using a variety of starting materials and reaction schemes. The methyl 2-fluoroacrylate prepared by the methods described herein can further be used to prepare patiromer calcium sorbitex.

The present invention is directed to a purification method for purifying a fluorine-containing polymerizable monomer of the formula (1), in which the fluorine-containing polymerizable monomer is purified by distillation in the coexistence of a phenolic compound A such as 6-tert-butyl-2,4-xylenol and a phenolic compound B such as 2,2′-methylene-bis(4-methyl-6-tert-butylphenol). ##STR00001##
By the combined use of the phenolic compound A and the phenolic compound B, it is possible to significantly suppress polymerization or oligomerization of the fluorine-containing polymerizable monomer even during industrial-production-scale distillation and efficiently purify the fluorine-containing polymerizable monomer by distillation.

The present invention is directed to a purification method for purifying a fluorine-containing polymerizable monomer of the formula (1), in which the fluorine-containing polymerizable monomer is purified by distillation in the coexistence of a phenolic compound A such as 6-tert-butyl-2,4-xylenol and a phenolic compound B such as 2,2′-methylene-bis(4-methyl-6-tert-butylphenol). ##STR00001##
By the combined use of the phenolic compound A and the phenolic compound B, it is possible to significantly suppress polymerization or oligomerization of the fluorine-containing polymerizable monomer even during industrial-production-scale distillation and efficiently purify the fluorine-containing polymerizable monomer by distillation.

A fluorine-containing compound represented by general formula (1) by which high water-repellency can be obtained despite the small number of fluorine atoms:

L-(R.sup.1—X—Rf—Y—R.sup.2).sub.n  (1)

wherein L represents an n-valent organic group; n represents an integer of 1 or more; Rf represents a linear or branched fluoroalkylene group containing 1 to 4 of at least any of a CF.sub.2 unit, a CFH unit and a CFRf′ unit, and optionally having an ether bond, wherein Rf′ represents a fluoroalkyl group having 1 carbon atom; R.sup.1 represents a direct bond, or a linear or branched hydrocarbon group having 1 to 4 carbon atoms; R.sup.2 represents a linear or branched hydrocarbon group having 7 to 29 carbon atoms, containing no fluorine atoms, and optionally having an ether bond; and X and Y each independently represent a direct bond or a divalent linking group.

The present disclosure addresses the problem of providing a method for purifying a halogen-containing (meth)acrylic acid ester, the method being capable of removing an alcohol to a high degree. This problem can be solved by a method for purifying a compound represented by formula (1):

##STR00001##

(wherein R.sup.1 and R.sup.2 are be the same or different and represent an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, a halogen atom, or a hydrogen atom, R.sup.3 represents an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituents, and X represents a fluoroalkyl group or a halogen atom),
the method comprising step (A) of mixing a composition comprising the compound represented by formula (1) and a compound represented by formula (2):

R.sup.4—OH  (2)

(wherein R.sup.4 is an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituents) with (i) a salt and/or (ii) a specific organic solvent to obtain a mixture; and step (B) of separating the mixture into two or more phases that are different from each other in terms of the content of the compound represented by formula (1).

The present disclosure addresses the problem of providing a method for purifying a halogen-containing (meth)acrylic acid ester, the method being capable of removing an alcohol to a high degree. This problem can be solved by a method for purifying a compound represented by formula (1):

##STR00001##

(wherein R.sup.1 and R.sup.2 are be the same or different and represent an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituents, a halogen atom, or a hydrogen atom, R.sup.3 represents an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituents, and X represents a fluoroalkyl group or a halogen atom),
the method comprising step (A) of mixing a composition comprising the compound represented by formula (1) and a compound represented by formula (2):

R.sup.4—OH  (2)

(wherein R.sup.4 is an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituents) with (i) a salt and/or (ii) a specific organic solvent to obtain a mixture; and step (B) of separating the mixture into two or more phases that are different from each other in terms of the content of the compound represented by formula (1).

The present disclosure addresses the problem of providing a method for purifying an acrylic acid ester compound. This problem can be solved by a method for purifying a compound represented by formula (1)

##STR00001##

(wherein R.sup.1 and R.sup.2 are the same as or different and each represent an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituent groups, a halogen atom, or a hydrogen atom, R.sup.3 is an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituent groups, and X is a fluoroalkyl group or a halogen atom), the method including step A of distilling composition A containing (a) the compound represented by formula (1), (b) an alcohol, and (c) a salt so as to obtain a concentrate containing the compound represented by formula (1).

The present disclosure addresses the problem of providing a method for purifying an acrylic acid ester compound. This problem can be solved by a method for purifying a compound represented by formula (1)

##STR00001##

(wherein R.sup.1 and R.sup.2 are the same as or different and each represent an alkyl group, a fluoroalkyl group, an aryl group optionally having one or more substituent groups, a halogen atom, or a hydrogen atom, R.sup.3 is an alkyl group, a fluoroalkyl group, or an aryl group optionally having one or more substituent groups, and X is a fluoroalkyl group or a halogen atom), the method including step A of distilling composition A containing (a) the compound represented by formula (1), (b) an alcohol, and (c) a salt so as to obtain a concentrate containing the compound represented by formula (1).