Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2001-02-26
2002-08-20
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S824000, C525S071000
Reexamination Certificate
active
06437040
ABSTRACT:
The present invention relates to novel water-soluble block polymers comprising a hydrophobic block and a hydrophilic block, the solubility and the self-association properties of which can be adjusted when they are diluted in water.
Numerous studies have been carried out on amphiphilic block polymers. These studies generally involve organic solvent media, more rarely aqueous media. This is because, in the amphiphilic block polymers studied to date, the strong hydrophobicity of the hydrophobic block generally results in irreversible and unbalanced phenomena of aggregation or of micelleization when operating in water. Control of the mechanisms and structures is then accomplished by changing to a solvent medium. The only amphiphilic block polymers with structures which have been studied at equilibrium are polymers exhibiting a hydrophobic block and a neutral water-soluble block, for example polyethylene (PEE)/poly(ethylene oxide) (PEO) or poly(propylene oxide)/poly(ethylene oxide) diblocks.
A few studies have been carried out on amphiphilic block polymers exhibiting a hydrophobic block and an anionic hydrophilic block. It has been shown that, when these polymers are soluble in water, they remain in the form of spherical micelles (star-like micelles). Furthermore, these polymers are only soluble when the anionic hydrophilic block is very high in weight in comparison to the hydrophobic block, which greatly restricts the number of polymers which can be used. Finally, they are not really soluble since it has been shown that their critical micelle concentration is extremely low. Because of the presence of micelles at very low concentrations, the systems obtained, when these copolymers are dissolved in water, are in fact suspensions with a viscosity which increases strongly with the concentration. Above a critical concentration of the order of 1% by weight, they become gels which are difficult to handle.
Without wishing to restrict the invention to a scientific theory, one aim of the present invention is to provide soluble copolymers, that is to say copolymers for which each macromolecule thereof has the property of being individually soluble without the appearance of aggregation or of micelleization.
Another aim of the present invention is to provide water-soluble copolymers with a hydrophobic/hydrophilic structure.
Another aim is to provide copolymers with a solubility which can be adjusted and with self-association properties which can be adjusted.
Another aim is to be able to obtain an aqueous solution of these copolymers which is liquid and transparent over a broad concentration range.
These aims and others are achieved by the present invention, this being because the latter relates to a block copolymer comprising at least one block of hydrophobic nature and at least one block of hydrophilic nature, the block of hydrophobic nature exhibiting hydrophilic units in an amount of between 33 and 99%, preferably between 33 and 80%, with respect to the total weight of the units of the hydrophobic block.
According to the invention, these copolymers are preferably prepared by a polymerization process referred to as living or controlled.
The invention also relates to a process for controlling the hydrophilic-lipophilic balance of amphiphilic block copolymers exhibiting at least one block resulting from the polymerization of hydrophilic monomers and at least one block resulting from the polymerization of hydrophobic monomers, in which process:
hydrophilic units are introduced into the block resulting from the polymerization of hydrophobic monomers, and/or
hydrophobic units are introduced into the block resulting from the polymerization of hydrophilic monomers.
Finally, the invention relates to the use of these block copolymers in particular as adhesion primers in paints or as wetting agents.
In the description which follows, the term “block of hydrophobic nature” is understood to mean a hydrophobic polymer block exhibiting hydrophilic units in an amount of between 33 and 99%, preferably between 33 and 80%, with respect to the total weight of the units of said block of hydrophobic nature. The term “unit” is understood to mean the part of the block which corresponds to one monomer unit.
Likewise, the term “block of hydrophilic nature” is understood to mean a polymer block comprising solely hydrophilic units or exhibiting at most 20% or from 1 to 20% by weight of hydrophobic units with respect to the total weight of the units of said block of hydrophilic nature. The block of hydrophilic nature is soluble in water.
The invention also relates to a process for controlling the hydrophilic-lipophilic balance of amphiphilic block copolymers exhibiting at least one block resulting from the polymerization of hydrophilic monomers and at least one block resulting from the polymerization of hydrophobic monomers, in which process:
hydrophilic units are introduced into the block resulting from the polymerization of hydrophobic monomers, and/or
hydrophobic units are introduced into the block resulting from the polymerization of hydrophilic monomers.
The properties of the copolymers according to the present invention can be obtained by the choice of the nature of the hydrophobic blocks and of the nature of the hydrophilic blocks, at least the hydrophobic blocks having to comprise hydrophilic units according to a precise amount.
According to a first alternative form, the blocks of hydrophobic nature and the blocks of hydrophilic nature can result from the copolymerization of hydrophobic and hydrophilic monomers. The amounts of hydrophilic and hydrophobic units in each of said blocks are then controlled by the respective contents of hydrophilic monomers and of hydrophobic monomers during the polymerization of the blocks.
Thus, the blocks of hydrophobic nature can result from the copolymerization of hydrophobic monomers and hydrophilic monomers, the hydrophilic monomers being present in an amount of between 33 and 99% by weight, preferably between 33 and 80% by weight, with respect to the total weight of the units of the hydrophobic block.
Likewise, the blocks of hydrophilic nature can result from the copolymerization of hydrophilic monomers and optionally of hydrophobic monomers, the hydrophobic monomers being present in an amount of less than 20% by weight, preferably of at least 1% by weight, or more preferably still of between 1 and 20%, with respect to the total weight of the units of the hydrophilic block.
According to a second alternative form, the blocks of hydrophobic nature and the blocks of hydrophilic nature of the preceding copolymers can result:
from the polymerization of monomers which can be rendered hydrophilic by hydrolysis and optionally of non-hydrolysable hydrophobic monomers and/or of hydrophilic monomers,
and then from the hydrolysis of the polymer obtained.
During the hydrolysis, the units corresponding to the hydrolysable monomers are hydrolysed to hydrophilic units.
The amounts of hydrophilic and hydrophobic units in each of said blocks are then controlled by the amount of each type of monomer and by the degree of hydrolysis.
According to this second alternative form, various implementations can be envisaged.
According to a first implementation, the block can be obtained by:
homopolymerization of hydrophobic monomers which can be rendered hydrophilic by hydrolysis, and
partial hydrolysis of the homopolymer obtained to a degree such that:
either, in the case of the blocks of hydrophobic nature, an amount of hydrophilic units of between 33 and 99%, preferably between 33 and 75%, with respect to the total weight of the units of the hydrophobic block is obtained,
or, in the case of the blocks of hydrophilic nature, an amount of hydrophobic units of less than 20% by weight, preferably of at least 1% by weight, more preferably still of between 1 and 20%, with respect to the total weight of the units of the hydrophilic block is obtained.
According to a second implementation, the blocks can be obtained by:
copolymerization of hydrophobic monomers which can be rendered hydrophilic by hydrolysis a
Anthony Olivier
Bonnet-Gonnet Cécile
Destarac Mathias
Farhoosh Roya
Joanicot Mathieu
Asinovsky Olga
Rhodia Chimie
Seidleck James J.
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