Copolymers with water-soluble blocks comprising a hydrophobic block and a hydrophilic block

Translation of description of equivalent WO 02068486 A2

WATER-SOLUBLE BLOCK COPOLYMERS COMPRISING A HYDROPHOBIC BLOCK AND A HYDROPHILIC BLOCK

The present invention relates to novel water-soluble block polymers comprising a hydrophobic block and a hydrophilic block, the solubility and selfassociation properties of which when diluted in water are adjustable.

Numerous studies have been conducted on amphiphilic block polymers. These studies usually involve organic solvent media, more rarely aqueous media. In fact, in the amphiphilic block polymers studied to date, the strong hydrophobicity of the hydrophobic block most often causes irreversible aggregation or micellization phenomena out of equilibrium, when working in water. The control mechanisms and structures is then through a passage in a solvent medium. The only amphiphilic block polymers whose structures have been studied at equilibrium are polymers having a hydrophobic block and a water-soluble neutral block, for example diblocks polyethylene (PEE) / polyethylene oxide (POE). ), propylene polyoxide / polyethylene oxide.

Some studies have been carried out on amphiphilic block polymers having a hydrophobic block and 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). In addition, these polymers are soluble only when the anionic hydrophilic block is very large in weight compared to the hydrophobic block, which greatly limits the number of usable polymers. Finally, they are not really soluble since it has been shown that their critical micellar concentration is extremely low. Due to the presence of micelles at very low concentrations, the systems obtained, when these copolymers are dissolved in water, are in fact suspensions whose viscosity increases strongly with the concentration.

Without wishing to limit the invention to a scientific theory, an aim of the present invention is to propose soluble copolymers, ie copolymers in which each macromolecule has the property of being individually soluble without the appearance of aggregation or micellisation. .

Another object of the present invention is to provide water-soluble copolymers of hydrophobic / hydrophilic structure.

Another object is to provide copolymers whose solubility and selfassociation properties are adjustable.

Another object is to obtain an aqueous solution of these copolymers, liquid and transparent over a wide concentration range. These and other objects are achieved by the present invention, which concerns in fact a block copolymer comprising at least one block of hydrophobic nature and at least one block of hydrophilic nature, the block of hydrophobic nature having hydrophilic units in an amount of between 33 and 99%, preferably between 33 and 80%, relative to the total weight of the units of the hydrophobic block.

According to the invention, these copolymers are preferably prepared by a so-called living or controlled polymerization process.

The invention also relates to a method for controlling the hydrophilic / hydrophobic balance of amphiphilic block copolymers having 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:

hydrophilic units in the block resulting from the polymerization of hydrophobic monomers, and / or

hydrophobic units in the block resulting from the polymerization of hydrophilic monomers.

Finally, the invention relates to the use of these block copolymers especially as adhesion primers in paints or as wetting agents.

In the following description, hydrophobic block is understood to mean a hydrophobic polymer block having hydrophilic units in an amount of between 33 and 99%, preferably between 33 and 80%, relative to the total weight of the units of said block of water. hydrophobic nature. By reason, we mean the part of the block corresponding to a monomer unit.

Similarly, the term "block of hydrophilic nature" means a polymer block comprising only hydrophilic units or having at most 20%, or from 1 to 20% by weight of hydrophobic units relative to the total weight of the units of said block of hydrophilic nature. The hydrophilic block is soluble in water.

The invention also relates to a method for controlling the hydrophilic / hydrophobic balance of amphiphilic block copolymers having at least one block resulting from the polymerization of hydrophilic monomers and at least one block resulting from the polymerization of hydrophobic monomers, into which:

hydrophilic units in the block resulting from the polymerization of hydrophobic monomers, and / or

hydrophobic units in 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 the nature of the hydrophilic blocks, at least the hydrophobic blocks must comprise hydrophilic units in a precise amount. According to a first variant, the blocks of hydrophobic nature and the blocks of hydrophilic nature may be derived from the copolymerization of hydrophobic and hydrophilic monomers. The quantities 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 be derived 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 relative to total weight of the hydrophobic block units.

And the blocks of hydrophilic nature may be derived 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, even more preferentially between 1 and 20%, relative to the total weight of the units of the hydrophilic block.

According to a second variant, the blocks of hydrophobic nature and the blocks of hydrophilic nature of the above copolymers may be derived from:

polymerization of monomers which can be rendered hydrophilic by hydrolysis and optionally nonhydrolyzable hydrophobic monomers and / or hydrophilic monomers,

- Then hydrolysis of the polymer obtained.

During hydrolysis, the units corresponding to the hydrolysable monomers are hydrolyzed into 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 rate of hydrolysis.

According to this second variant, various implementations can be envisaged.

According to a first implementation, the blocks can be obtained by:

homopolymerization of hydrophobic monomers which can be rendered hydrophilic by hydrolysis, and

partial hydrolysis of the homopolymer obtained at a rate such that:

or, in the case of blocks of hydrophobic nature, an amount of hydrophilic units of between 33 and 99%, preferably between 33 and 75%, relative to the total weight of the units of the hydrophobic block,

or, in the case of blocks of hydrophilic nature, an amount of hydrophobic units of less than 20% by weight, preferably of at least 1% by weight, even more preferably of between 1 and 20%, relative to the total weight patterns of the hydrophilic block.

According to a second implementation, the blocks can be obtained by:

copolymerization of hydrophilic monomers which can be rendered hydrophilic by hydrolysis and of hydrophobic monomers which can not be rendered hydrophilic by hydrolysis, and then

total or partial hydrolysis of the polymer obtained.

According to this second implementation, the quantity of hydrophilic and hydrophobic units may depend on two criteria: the contents of the different types of monomers and the degree of hydrolysis.

If the hydrolysis is partial, one can play both on the monomer content and the rate of hydrolysis.

According to a third implementation, the blocks can be obtained by:

copolymerization of hydrophilic monomers which can be rendered hydrophilic by hydrolysis and hydrophilic monomers, and

partial hydrolysis of the polymer obtained at a rate such that:

. or, in the case of blocks of hydrophobic nature, an amount of hydrophilic units of between 33 and 99%, preferably between 33 and 80%, relative to the total weight of the units constituting the group of hydrophobic nature,

. or, in the case of blocks of hydrophilic nature, an amount of hydrophobic units of less than 20% by weight, preferably of at least 1% by weight, even more preferably between 1 and 20%, relative to the total weight of patterns constituting the group of hydrophilic nature.

In general, the hydrophobic monomers can be chosen from:

vinylaromatic monomers, such as styrene,

dienics such as butadiene,

alkyl acrylates and methacrylates in which the alkyl group contains from 1 to 10 carbon atoms, such as methyl, ethyl, n-butyl, 2-ethylhexyl, t-butyl, isobornyl, phenyl and benzyl acrylates and methacrylates.

Preferably, it is styrene.

The hydrophilic monomers can be chosen from:

ethylenically unsaturated carboxylic acids such as acrylic and methacrylic acids,

neutral hydrophilic monomers such as acrylamide and its derivatives (N-methylacrylamide, N-isopropylacrylamide), and methacrylamide. By way of examples, mention may also be made of polyethylene glycol (meth) acrylate type macromonamers, polyvinyl alcohol (meth) acrylate, and poly (hydroxy (Ci-C) -alkyl (meth) acrylate (meth) acrylate ), poly (N-methylol acrylamide) (meth) acrylate, and poly ((meth) acrylamide) (meth) acrylate. These macromonomers can be obtained for example by transesterification of methyl acrylate or methacrylate, or (meth) acrylic anhydride or acryloyl chloride or meth acryloyl. They can also be obtained by direct esterification of acrylic or methacrylic acid.

acrylic and methacrylic acid hydrolyzable esters such as methyl acrylate, ethyl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, tert-butyl acrylate,

vinyl hydrolysable acetate in vinyl alcohol units,

methacrylate and quaternized 2-dimethylaminoethyl acrylate (madamquat and adamquat),

acrylamide and (meth) acrylamide.

Preferably, the block copolymers according to the invention are diblock copolymers. However, it may also be triblock copolymers, or even multiblock.

According to the preferred embodiment of the invention, the copolymer is a diblock copolymer comprising a block of hydrophilic nature and a block of hydrophobic nature, in which:

the block of hydrophilic nature comprises acrylic acid (AA) units and ethyl acrylate (AEt) units,

and the block of hydrophobic nature comprises styrene (St) and methacrylic acid (AMA) and / or hydroxyethyl methacrylate (HEMA) units.

Preferably, according to this embodiment, the block of hydrophilic nature is derived from:

the polymerization of acrylic acid (AA) and of ethyl acrylate (AEth) in a weight ratio AEt / AA of 10/90,

and then hydrolyzing the polymer obtained at a level of at least 33 mol%.

Preferably, the block of hydrophobic nature is itself derived from the polymerization of a monomer mixture comprising at least 33% by weight of styrene.

Generally, the block polymers according to the invention have a molecular weight of at most 100,000 g / mol, preferably at least 1000 g / mol.

In general, the preceding block copolymers can be obtained by any so-called living or controlled polymerization process such as, for example:

radical polymerization controlled by xanthates according to the teaching of application WO 98/58974,

the radical polymerization controlled by the dithioesters according to the teaching of the application WO 97/01478

the polymerization using nitroxide precursors according to the teaching of application WO 99/03894,

the radical polymerization controlled by dithiocarbamates according to the teaching of application WO 99/31144,

the atom transfer radical polymerization (ATRP) according to the teaching of the application WO 96/30421,

radical polymerization controlled by iniferters according to the teaching of Otu et al., Makromol. Chem. Rapid. Commun., 3, 127 (1982),

controlled radical polymerization by degenerative transfer of iodine according to the teaching of Tatemoto et al., Jap. 50, 127, 991 (1975), Daikin Kogyo Co. Itd Japan and Matyjaszewski et al., Macromolecules, 28, 2093 (1995),

group transfer polymerization according to the Webster OW teaching "Group Transfer Polymerization", p. 580-588 of 'Εncyclopedia of Polymer Science and Engineering', volJ and HF Mark, NM Bikales, CG Overberger and G. Menges, Eds., Wiley Interscience, New York, 1987,

radical polymerization controlled by tetraphenylethane derivatives (D. Braun et al., Macromol.Symp.111, 63 (1996)),

radical polymerization controlled by the organocobalt complexes (Wayland et al J.Am.Chem.Soc.Lu. 116,7973 (1994)).

The preferred polymerization is live radical polymerization using xanthates.

The invention therefore also relates to a process for preparing these block polymers. This method consists in: 1 - putting in contact:

at least one ethylenically unsaturated monomer,

at least one source of free radicals, and

at least one compound of formula (I):

S

W

C - S - R1 (I)

/

R in which:

. R represents a group R2O-, R2R'2N- or R3- with:

R2 and R'2, identical or different, representing a group (i) alkyl, acyl, aryl, alkene or alkyne, or a ring (ii) carbon, saturated or unsaturated, optionally aromatic, or a heterocycle (iii), saturated or no, these groups and cycles (i), (ii) and (iii) may be substituted,

R3 representing H, Cl, an alkyl, aryl, alkene or alkyne group, a saturated or unsaturated (hetero) ring, optionally substituted, an alkylthio, alkoxycarbonyl, aryloxycarbonyl, carboxy, acyloxy, carbamoyl, cyano, dialkyl or diarylphosphonato group; , dialkyl- or diaryl-phosphinato, a polymer chain,

. R1 represents an optionally substituted (i) alkyl, acyl, aryl, alkene or alkyne group, or a saturated or unsaturated, optionally substituted or aromatic (ii) saturated or unsaturated carbonyl ring, or optionally saturated or unsaturated heterocycle (iii), or a polymer chain,

2- repeat at least once the previous contacting using:

monomers different from the previous implementation, and

in the place of the precursor compound of formula (I), the polymer resulting from the preceding implementation,

Optionally, hydrolyzing the copolymer obtained.

The groups R1, R2, R'2 and R3 may be substituted by alkyl groups, substituted phenyls, substituted aromatic groups or groups: oxo, alkoxycarbonyl or aryloxycarbonyl (-COOR), carboxy (-COOH), acyloxy (-O2CR ), carbamoyl (-CONR2), cyano (-CN), alkylcarbonyl, alkylarylcarbonyl, arylcarbonyl, arylalkylcarbonyl, isocyanato, phthalimido, maleimido, succinimido, amidino, guanidino, hydroxy (-OH), amino (-NR2), halogen, allyl, epoxy, alkoxy (-OR), S-alkyl, S-aryl, silyl, groups having a hydrophilic or ionic character such as alkali metal salts of carboxylic acids, alkaline salts of sulfonic acid, polyalkylene oxide chains (POE, POP), cationic substituents (quaternary ammonium salts), R representing an alkyl or aryl group.

Preferably, the compound of formula (I) is a dithiocarbonate chosen from the following compounds of formulas (IA), (IB) and (IC):

W

C - S - R1 (IA)

/ O-R2

R^{2 "}- (^" O - C - S - R¹) P (IB)

R^{1 '}- (~ S - C - O - R²)peak)

II

S in which:

. R2 and R2 'represent a group (i) alkyl, acyl, aryl, alkene or alkyne, or a ring (ii) carbon, saturated or unsaturated, optionally aromatic, or a heterocycle (iii), saturated or not, these groups and rings (i), (ii) and (iii) may be substituted,

. R1 and R1 'represent an optionally substituted (i) alkyl, acyl, aryl, alkene or alkyne group, or a saturated or unsaturated, optionally substituted or aromatic carbon (ii) ring, or a saturated or unsaturated heterocycle (iii), optionally substituted, a polymer chain,

. p is between 2 and 10.

During step 1, a first block of the polymer is synthesized of hydrophilic or hydrophobic nature depending on the nature and amount of the monomers used. In step 2, the other block of the polymer is synthesized.

The ethylenically unsaturated monomers will be chosen from hydrophilic, hydrophobic and hydrolyzable monomers previously defined in the proportions adapted to obtain a block copolymer whose blocks have the characteristics of the invention. According to this method, if all the successive polymerizations are carried out in the same reactor, it is generally preferable that all the monomers used in one step have been consumed before the polymerization of the next step begins, therefore before the new monomers are introduced. However, it may happen that the hydrophobic or hydrophilic monomers of the previous step are still present in the reactor during the polymerization of the next block. In that case,

For more details on the previous polymerization process, reference may be made to the contents of US Pat. No. 6,153,705 cited as a reference in the present description.

The hydrolysis can be carried out using a base or an acid. The base may be chosen from hydroxides of alkali or alkaline earth metals, such as sodium hydroxide or potassium hydroxide, alkali metal alcoholates such as sodium methoxide, sodium ethoxide, potassium methoxide, ethylate potassium, potassium t-butoxide, ammonia and amines such as triethylamine. The acids may be chosen from sulfuric acid, hydrochloric acid and para-toluenesulphonic acid. It is also possible to use an ion exchange resin or an ion exchange membrane of cationic or anionic type. The hydrolysis is generally carried out at a temperature between 5 and 100 ° C, preferably between 15 and 90 ° C.

After hydrolysis, the block copolymer can be washed, for example by dialysis against water or with the aid of a solvent such as alcohol. It can also be precipitated by lowering the pH below 3.5.

The hydrolysis may be carried out on a one-piece polymer, which will then be associated with other blocks, or on the final block polymer.

Finally, the inventionthe use of the foregoing block copolymers as adhesion promoters. They can also be used as wetting agents or hydrophilizing agents for coating more or less hydrophobic surfaces with residual effect after rinsing. Preferably, the polymers may be used in an amount generally between 0.1% and 10% by weight relative to the aqueous medium. In particular, the block copolymers according to the invention have the advantage of improving the adhesion of paints to hydrophobic substrates such as plastic substrates and of increasing the adhesion of fibers and plastic supports with compounds derived from aqueous dispersions (cement, mastics). In this particular application as adhesion agent, it is recommended to use from 0.1 to 10%, preferably from 0.5 to 5% by weight of copolymer relative to the total weight of the paint. In the application as wetting agent in aqueous solution, it is recommended to use an amount of 0.01 to 3%, preferably 0.1 to 1% by weight of copolymer relative to the total weight of said solution.

The following examples illustrate the invention without, however, limiting its scope.

In the following examples:

Mn represents the number-average molecular mass Mn of the polymers, Mn is expressed in polystyrene equivalents (g / mol),

Mw represents the weight average molecular weight (g / mol),

Mw / Mn represents the polydispersity index,

the polymers, before hydrolysis, are analyzed by chromatography (GPC) with THF as elution solvent.

I) Solubility of a poly (styrene / acrylic acid) -b-polyacid diblock copolymer in water:

The solubility of four diblock copolymers below of a total molecular weight of 16,000 g / mol is studied with a first random block copolymer of styrene (Sty), acrylic acid (AA) and methacrylic acid (MAA) of a weight Mn molecular weight of 1000-2000 and a second random copolymer block of acrylic acid (AA) and methacrylic acid (MAA) with Mn = 15,000 - 14,000. These copolymers are prepared by following the procedure below while choosing the quantities of monomers as indicated in Table 1 below: Table 1 Diblock copolymers:% by weight of acrylic acid in the first block [[Style [MA]]₀, 2} -b- {[AA]₁₉₈[MAA]₁₂} (1) 0% comparative example {[Sty]₁₄ [MY]₀,₅[AA]₅} -b- {[AAWMAAJ_! ,} (2) 23% comparative example {[Sty]₁o [MA] o_l5[AA]₁₀} -b- {[AA]₁₈₅[MAA]₁₁} (3) 48%

{[Sty]₅ [MA] o₅[AA]₁₅} -b- {[AA]₁₈₅[MAA]₁₁} (4) 73%

{[Sty]₇ [MY]₄ [AA]₂₁₂} (5) n / a comparative example

These copolymers are also compared with the poly (styrene / acrylic acid) random copolymer (5) as defined above with an Mn of 16,000 and a mass ratio of St / AA / MA = 4.6 / 93 / 2.4. Both light scattering and spectrofluorometry techniques are used to study the properties of these copolymers in aqueous solutions.

IA) Synthesis and hydrolysis of the comparative copolymer (1): IA.1) Synthesis of the diblock (1):

Synthesis of a random copolymer of styrene and methacrylic acid. Mass ratios: St / AMA = 98/2.

The polymerization is carried out in emulsion, in a jacketed reactor equipped with a tri-pale stainless steel stirrer. 488.8 g of water, 10.13 g of dodecyl sulphate, sodium salt (Aldrich) and 0.11 g of sodium carbonate Na 2 CO 3 are introduced at room temperature. The resulting mixture is stirred for 30 minutes (190 rpm) under nitrogen. The stirring continues for an additional 55 minutes during which the temperature is raised to 75 ° C., then a mixture comprising 3.03 g of styrene and 6.4 g of alpha- (o-ethylxanthyl) propionate is incorporated. methyl (CH3CHCO2Me) SCSOEt and 0.061 g methacrylic acid. The temperature is then raised to 85 ° C. and 1.40 g of ammonium persulfate (NH4) 2S2θβ are added.

After five minutes, 27.22 g of styrene and 0.55 g of methacrylic acid are added for one hour. After complete addition, an emulsion polymer (latex) is obtained, which is maintained at 85 ° C for one hour.

53.77 g of the previously obtained emulsion copolymer (first block) are taken. To the remaining emulsion, 0.64 g of ammonium persulfate (NH4) 2S2θβ and 5.5 g of water are added at 85 ° C. After five minutes, the addition of a mixture of:

567.9 g of ethyl acrylate (AEt),

11.59 g of methacrylic acid (AMA), and simultaneously another compound of:

-445.9 g of water

-0.65 g of Na2Cθ3 The addition lasts 1 hour. The system is maintained at this temperature for an additional three hours. IA.2) Hydrolysis:

The diblock copolymer (1) thus obtained is then hydrolyzed. The reaction is carried out in a jacketed reactor equipped with a tri-pale stainless steel stirrer. We introduce:

50 g of the above copolymer (the dry extract at 41.37%),

- 265 g of water (to adjust the dry extract to 4%).

The temperature is raised to 85 ° C and yet the emulsion is stirred vigorously. Then 194 g of 2N sodium hydroxide (corresponding to two molar equivalents of sodium hydroxide with respect to the ethyl acrylate) are added thereto for two hours. After complete addition of the sodium hydroxide, the temperature is raised to 95 ° C. and the reaction mixture is maintained under these conditions for 48 hours. IB) Synthesis and hydrolysis of the comparative copolymer (2): IB-1. Synthesis of the diblock (2):

Synthesis of a random copolymer of styrene, methacrylic acid and ethyl acrylate with mass ratios: St / AMA / AEt = 75/2/23.

The polymerization is carried out in emulsion, in a jacketed reactor equipped with a tri-pale stainless steel stirrer. 840 g of water, 12.76 g of dodecyl sulphate, sodium salt (Aldrich) and 0.28 g of sodium carbonate Na 2 CO 3 are introduced at room temperature. The resulting mixture is stirred for 30 minutes (190 rpm) under nitrogen. The stirring is continued for a further 55 minutes during which the temperature is raised to 75 ° C., then a mixture comprising 5.93 g of styrene and 8.24 g of alpha- (o-ethylxanthyl) propionate is incorporated. methyl (CH3CHCO2Me) SCSOEt, 0.16 g of methacrylic acid and 1.82 g of ethyl acrylate. The temperature is then raised to 85 ° C. and 1.8992 g of ammonium persulfate (NH) 2 S 2 O 8 are added.

After five minutes, 53.46 g of styrene, 1.43 g of methacrylic acid and 16.41 g of ethyl acrylate are added for one hour. After complete addition, an emulsion polymer (latex) is obtained, which is maintained at 85 ° C for one hour.

314 g of the previously obtained emulsion copolymer are taken. 0.60 g of ammonium persulfate (NH4) 2S2θβ and 8 g of water are added to it at 85 ° C. After five minutes, the addition of a mixture of:

503.96 g of ethyl acrylate (AEt), 10.28 g of methacrylic acid (AMA),

And simultaneously another compound of: -320 g of water -0.57 g of Na2CO3 The addition lasts 1 hour. The system is maintained at this temperature for an additional three hours.

IB-2) Hydrolysis of the diblock copolymer:

The hydrolysis is also carried out in a jacketed reactor equipped with a tri-pale stainless steel stirrer. We introduce:

49.9 g of the above copolymer (the dry extract at 39.66%),

- 264.3 g of water (to adjust the dry extract to 4%).

The temperature is raised to 85 ° C and yet the emulsion is stirred vigorously. Then 185 g of 2N sodium hydroxide (corresponding to two molar equivalents of sodium hydroxide with respect to the ethyl acrylate) are added thereto for two hours. After complete addition of the sodium hydroxide, the temperature is raised to 95 ° C. and the reaction is maintained under these conditions for 48 hours. IC) Synthesis and hydrolysis of the copolymer (3): 1.C.1) Synthesis of the diblock (3):

Synthesis of a random copolymer of styrene, methacrylic acid and ethyl acrylate with mass ratios: St / AMA / AEt = 55/2/43.

The polymerization is carried out in emulsion, in a jacketed reactor equipped with a tri-pale stainless steel stirrer. 572 g of water, 11.4 g of dodecyl sulphate, sodium salt (Aldrich) and 0.25 g of sodium carbonate Na 2 CO 3 are introduced at room temperature. The resulting mixture is stirred for 30 minutes (190 rpm) under nitrogen. The stirring continues for a further period of 55 minutes during which the temperature is raised to 75 ° C., and a mixture comprising 3.54 g of styrene and 7.36 g of alpha- (o-ethylxanthyl) propionate is then added. methyl (CH3CHCθ2Me) SCSOEt, 0.14 g of methacrylic acid and 3.39 g of ethyl acrylate. The temperature is then raised to 85 ° C. and 1.65 g of ammonium persulfate (NH₄) 2S2θ8.

After five minutes, 31.85 g of styrene, 1.27 g of methacrylic acid and 30.58 g of ethyl acrylate are added for one hour. After complete addition, an emulsion polymer (latex) is obtained, which is maintained at 85 ° C for one hour.

53.10 g of the previously obtained emulsion copolymer are obtained. 0.62 g of ammonium persulphate (NH4) 2S2θβ and 5.5 g of water are added to it at 85 ° C. After five minutes, the addition of a mixture of:

519.57 g of ethyl acrylate (AEt), 10.60 g of methacrylic acid (AMA),

And simultaneously another consists of:

-440 g of water -0.59 g of Na2∞3 The addition lasts 1 hour. The system is maintained at this temperature for an additional three hours.

IC-2) Hydrolysis of the diblock copolymer:

The hydrolysis is also carried out in a jacketed reactor equipped with a tri-pale stainless steel stirrer. We introduce:

50 g of the above copolymer (40.46% solids content),

- 269 g of water (to adjust the dry extract to 4%).

The temperature is raised to 85 ° C and yet the emulsion is stirred vigorously. Then 182 g of 2N sodium hydroxide (corresponding to two molar equivalents of sodium hydroxide with respect to the ethyl acrylate) are added for two hours. After complete addition of the sodium hydroxide, the temperature is raised to 95 ° C. and the reaction is maintained under these conditions for 48 hours. ID) Synthesis and hydrolysis of the copolymer (4): 1D-1) Synthesis of the diloc (4):

Synthesis of a random copolymer of styrene, methacrylic acid and ethyl acrylate with mass ratios: St / AMA / AEt = 25/2/73.

The polymerization is carried out in emulsion, in a jacketed reactor equipped with a tri-pale stainless steel stirrer. 875 g of water, 13.9 g of dodecyl sulphate, sodium salt (Aldrich) and 0.31 g of sodium carbonate Na 2 CO 3 are introduced at room temperature. The resulting mixture is stirred for 30 minutes (190 rpm) under nitrogen. The stirring continues for a further period of 55 minutes during which the temperature is raised to 75 ° C., and then a mixture comprising 2.16 g of styrene and 9.01 g of alpha- (o-ethylxanthyl) propionate is incorporated. methyl (CH3CHCO2Me) SCSOEt, 0.17 g of methacrylic acid and 6.32 g of ethyl acrylate. The temperature is then raised to 85 ° C. and 1. 58 g of ammonium persulfate (NH₄) 2S2θβ.

After five minutes, 19.49 g of styrene, 1. 56 g of methacrylic acid and 56.91 g of ethyl acrylate are added for one hour. After complete addition, an emulsion polymer (latex) is obtained, which is maintained at 85 ° C for one hour.

197.29 g of the previously obtained emulsion copolymer are obtained. 0.79 g of ammonium persulfate (NH4) 2S2θβ and 3.5 g of water are added to it at 85 ° C. After five minutes, the addition of a mixture of:

661, 27 g of ethyl acrylate (AEt), 13.49 g of methacrylic acid (AMA),

And simultaneously another compound of:

-420 g of water -0.75 g of Na2Cθ3 The addition lasts 1 hour. The system is maintained at this temperature for an additional three hours. ID-2) Hydrolysis of the diblock copolymer:

The hydrolysis is also carried out in a jacketed reactor equipped with a tri-pale stainless steel stirrer. We introduce:

54 g of the above copolymer (35.09% solids content),

- 250.8g of water (to adjust the dry extract to 4%).

The temperature is raised to 85 ° C and yet the emulsion is stirred vigorously. Then 182 g of 2N sodium hydroxide (corresponding to two molar equivalents of sodium hydroxide with respect to the ethyl acrylate) are added for two hours. After complete addition of the sodium hydroxide, the temperature is raised to 95 ° C. and the reaction is maintained under these conditions for 48 hours. IE) Synthesis and hydrolysis of the copolymer (5) 1E-1) Synthesis of a random copolymer of styrene, methacrylic acid and ethyl acrylate with mass ratios: St / AMA / AEt = 4.6 / 2 , 4/93.

The polymerization is carried out in emulsion, in a jacketed reactor equipped with a tri-pale stainless steel stirrer. 492 g of water, 4.79 g of dodecyl sulphate, sodium salt (Aldrich) and 1.39 g of sodium carbonate Na 2 CO 3 are introduced at room temperature. The resulting mixture is stirred for 30 minutes (190 rpm) under nitrogen. The stirring continues for a further period of 55 minutes during which the temperature is raised to 75 ° C., then a mixture comprising 1.45 g of styrene and 3.04 g of alpha- (o-ethylxanthyl) propionate is incorporated. methyl (CH3CHCO2Me) SCSOEt, 0.77 g of methacrylic acid and 29.67 g of ethyl acrylate.

The temperature is then raised to 85 ° C. and 1.27 g of ammonium persulfate (NH₄) 2S₂θ8.

After five minutes, 13.10 g of styrene, 6.95 g of methacrylic acid and 267.30 g of ethyl acrylate are added for one hour. After complete addition, an emulsion polymer (latex) is obtained, which is maintained at 85 ° C for one hour. IE-2) Hydrolysis of the copolymer:

The hydrolysis of the copolymer is also carried out in a jacketed reactor equipped with a tri-pale stainless steel stirrer. We introduce:

83 g of the above copolymer (the dry extract at 36%),

- 136g of water (to adjust the dry extract to 6%).

The temperature is raised to 85 ° C and yet the emulsion is stirred vigorously. Then 281 g of 2N sodium hydroxide (corresponding to two molar equivalents of sodium hydroxide with respect to the ethyl acrylate) are added for two hours. After complete addition of the sodium hydroxide, the temperature is raised to 95 ° C. and the reaction is maintained under these conditions for 48 hours.

All copolymer solutions 1) to 5) are then dialysed to remove excess NaOH and sodium dodecyl sulfate. Deionized water was dialyzed using a SPECTRA / POR® membrane limit of 3500 (cu-off) molecular weight for several days until the conductivity dropped to 20 μS / cm. The solution is then filtered and lyophilized. The powder obtained is then resolubilized in deionized water.

Measurements of light diffusion carried out on the solutions of the copolymers 1 to 5 thus obtained, demonstrate that the copolymers 3, 4 and 5 are soluble whereas the copolymers 1 and 2 can be considered as insoluble. The term "soluble" as indicated above means that each macromolecule is individually solubilized without aggregation or micellization. This result is also confirmed by spectrofluorometry and electron microscopy measurements. II) Illustration of the wetting agent properties of the copolymers (1) to (5) prepared above:

The treated surfaces are, in a first series of experiments, silica glass specimens methylated by a silanation reaction carried out in a 90 ° C oven using trichlorosilane for about one hour. The test pieces are washed and stored in alcohol before use. The drop angles of advance and retreat of a drop of water are measured respectively at angles of 90 ° and 76 °.

According to a first method, the test pieces are immersed in the copolymer solutions and then rinsed abundantly with water or these solutions are sprayed onto the test pieces and dried.

The forward and back angles are measured with a Hart Rough autogoniometer. To measure the advancing angle, a syringe of deionized water is placed so that the tip of the syringe is placed 3 mm from the surface of the specimen before dropping a drop. The angle is automatically measured by the Ramé Hart autogoniometer within 10 seconds. When two consecutive angle measurements are identical, this measurement is then the advancing angle. The back angle is measured by pumping small amounts of droplet liquid into the syringe and measuring the angles between these volume reductions. These measurements are repeated until two identical consecutive angle measurements are obtained, which is then the angle of retreat. The tested copolymer solutions contain or do not contain sodium chloride. The results obtained are collated in Table 2 below. Table 2

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From Table 2, it appears that the comparative copolymers (1) and (5) have practically no wetting agent property whereas the copolymers (3) and (4) have this property, the copolymer (3) giving the best results especially in the presence of NaCl. Further measurements are carried out using the copolymer (3) in aqueous solution at 0.58% by weight with 0.1 M NaCl and various hydrophobic supports, namely, methyl glass, polyvinyl chloride (PVC), polypropylene (PP), acrylic plastic and ABS resin. The results obtained are summarized in Table 3 below. <img file="WO02068486A2_D0003.tif" />

From the taleau 3, it appears that the angles of retreat obtained are always less than 18 °. Surprisingly and unexpectedly, suitable results are obtained with polypropylene, a carrier known to be very difficult to wettable. III) Illustration of the properties as adhesion primer of the copolymers (1) to (4) prepared above:

The copolymers (1) to (4) are used in the state after dialysis and neutralization at pH 9 or not. A solution at 0.1% in water of the polymers of Examples (1) to (4) is coated on various plastic surfaces with a film puller in order to deposit a film 50 microns thick. These surfaces are made of polyamide (PA), polycarbonate (PC), polyethylene terephthalate (PETP), polymethylmethacrylate (PMMA), PS (polystyrene) and polyvinyl chloride (PVC). After drying, a latex film (commercial latex of Rhodia DS 1003) is coated with a film puller in order to deposit a 1.5 mm thick film. The latex film is then peeled at a 90 ° angle from the surface with a traction machine. The peel strength is measured at a constant tensile speed of 300mm per minute.

The results obtained are summarized in Table 4 below.

It can be seen from Table 4 that the dry adhesion of the latex film is greatly increased on all the plastic surfaces previously coated with the solutions of the copolyères of Examples (3) and (4) according to the invention, compared with the adhesion control latex film used without pre-coating or pre-coating with the copolyter solutions of Comparative Examples (1) and (2). It is remarkable that the copolymer of Example (4) gives excellent results on all types of support (maximum strength), and that the copolymer of Example 3 also gives very good results. The copolymers of Comparative Examples (1) and (2) give poor results.

Table 4

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