FR2867781A1 - POLYMERS WITH ISOCYANATE FUNCTIONS OBTAINED FROM (CO) POLYMERS WITH MOBILE HYDROGEN FUNCTIONS, THEIR OBTAINING AND THEIR USE IN COATING COMPOSITIONS - Google Patents

Abstract

The present invention relates to a process for obtaining (co) polymers carrying isocyanate functional groups from (co) polymers bearing functional groups with mobile hydrogen.This process is characterized by the fact that a (co) carrier polymer is subjected to functional hydrogen function with the action of an isocyanate compound carrying at least two isocyanate functional groups, at least one of which is free. Application to the preparation of coating compositions.

Description

2867781 1

  POLYMERS WITH ISOCYANATE FUNCTIONS OBTAINED

  The present invention relates to polyisocyanate (optionally masked) polyisocyanate (co) polymers derived from (co) polymers carrying functional groups (s), and to their use in coating compositions with a mobile hydroperoxide function. ) with mobile hydrogen (s).

  During the last century, the coating techniques are more and more interested in soft, even soft and self-healing coatings. However, it is difficult to obtain such coatings from hardeners and in particular from isocyanates currently on the market.

  Moreover, the synthesis of (co) polymers bearing isocyanate functional groups, in particular free isocyanate functions, is particularly delicate and difficult.

  Similarly, it is not easy to simply obtain highly functionalized polymer systems in isocyanate functions.

  Indeed, the isocyanate function is so reactive that the usual polymerization of monomers with double bond bearing isocyanate functions is relatively difficult to implement and requires particularly cumbersome precautions.

  Another way of functionalizing already formed (co) polymers presents the risk of creating bridges between the different branches of the (co) polymer or even inadvertently crosslinking the (co) polymers with each other.

  There is also the risk of forming loops by reaction between a di-functional isocyanate and two functions with mobile hydrogens within the same (co) polymer, which lowers the crosslinking power and the functionality of said (co) polymer .

  In the course of the present description, mention will be made repeatedly of (co) polymer with controlled architecture (controlled in the English sense of the term). Under this concept we must understand (co) polymers, or rather copolymers, whose topological distribution of patterns is not entirely statistical, and whose polymerization is organized to obtain specific architectures. This can be achieved using so-called living polymerizations. An essential characteristic of these living polymerizations is to be able to regulate the chain propagation sites and to freeze them at the end of a polymerization sequence so that the latter can be resumed in a subsequent sequence starting from these same sites and if necessary with different operating conditions and / or reaction medium. Thus the maintenance of the chain propagation site makes it possible to chain polymer fragments (or blocks) of different chemical nature, in particular along the same polymer chain, that is to say which make it possible to resume the polymerization. after modifying the reaction medium or the operating conditions.

  Thus, the (co) polymers with controlled architecture may be (co) polymers (homopolymers) or copolymers (statistics, diblocks, triblocks, multiblocks, grafted or star and / or microgel, linear, or hyperbranched). More specifically, within the meaning of the invention, the term "polymer architecture controlled" a (co) polymer based on two or more monomers having a controlled arrangement of these different monomer units constituting it.

  Listed below are various types of (co) polymers with controlled architecture, with their definitions. This enumeration is by no means an exhaustive list; however, it is a teaching by the example of what is a (co) polymer architecture controlled. The types listed are in various interesting titles.

  (Co) linear polymers These are (co) polymers consisting of two or more blocks placed one after the other, such as the wagons of a subway train; or in a single block whose architecture, including dispersity, is itself controlled, for example having a concentration gradient.

  (Co) polymers of branched structure or branched (co) polymers These are (co) polymers having several arms (at least three arms whereas a linear (co) polymer is deemed to have two arms articulating around a center possibly arbitrary).

  (Co) Comb combers These arms can be organized in particular as a comb.

  Most often the teeth of the comb are separate blocks of the (co) polymer to which they attach.

  Star (co) polymers star (co) polymers consist of several arms attached to a center; among the (co) polymers in star there are two main categories: those whose central part is narrow and those whose central part is extended. It is customary to distinguish them and to classify them according to their mode of synthesis.

  (Co) polymer star sensu stricto (that is to say, narrow central part) The first category corresponds to a first type of preparation where the formation of the arms of (co) polymers occurs from a multifunctional compound constituting center (core-first technique) (Kennedy, JP, et al., Macromolecules, 29, 8631 (1996), Deffieux, A. et al., 25, 6744, (1992), Gnanou, Y. and al. Ibid, 31, 6748 (1998)). and a second type where the molecules of (co) polymers that will constitute the arms are first synthesized and then bonded together on a core to form a star-shaped (co) polymer ("arm-first" technique) . Among the methods that can be used to link the arms, there may be mentioned the method comprising the reaction of these arms with a compound having a plurality of functional groups capable of reacting with terminal antagonistic functional groups of said arms (Fetters, LJ and al., Macromolecules, 19, 215 (1986), Hadjichristidis, N. et al., Macromolecules, 26, 2479 (1993), Roovers, J. and al., Macromolecules, 26, 4324 (1993)). These first types correspond to a star in the strict sense.

  The (co) polymer stars sensu stricto will hereinafter be referred to as a star, while those of the other star category, which is hereinafter described, will be referred to as microgel.

  (Co) Microgel-type (that is, broad-core) star polymers This second category has a structure whose center is looser and wider. It is simpler to define them by their method of production. Such microgel (co) polymer is likely to come from another mode of synthesis.

  This mode corresponds to a method where the molecules of (co) polymers that will constitute the arms are first synthesized and then bonded together on a core to form a star-shaped (co) polymer ("arm-first" technique). ). This technique thus makes it possible to prepare statistical microgels in the form of a star, in particular by so-called living cationic polymerization (Higashimura, T. et al., Macromolecules, 1996, 29, 1772).

  Recently, a method for the synthesis of random star-shaped microgels has been proposed from the coupling of linear (co) polymer chains preformed by controlled radical polymerization with a multiethylenically unsaturated monomer. The techniques used for this purpose may involve various control agents and in particular agents carrying thiocarbonylthio groups such as dithioesters in a reversible fragmentation addition method (WO 2000002939). In this case, the reactivatable groups derived from linear precursors are located at the core of the (co) star polymers thus formed.

  Microgels also include polymers that can be prepared by means of a radical polymerization technique involving a composition comprising at least one crosslinking monomer, a source of free radicals and at least one transfer agent, and optionally followed in a second step, or in a second step, a (co) polymerization of monomer (s) monounsaturated. This method of synthesis is described in the patent application WO 2004014535. As will be seen later, the transfer agents may in particular be chosen from xanthates of formula RSC (= S) -OR ', as described in the patent applications WO 98/58974, WO 00/75207 and WO 01/042312.

  As living polymerization may be mentioned especially ionic and radical techniques.

  The (co) polymers with controlled architecture are usually prepared by living ionic polymerization. This type of polymerization has the disadvantage of only permitting the polymerization of certain types of apolar monomers, in particular styrene and butadiene, and of requiring a particularly pure reaction medium and often lower than ambient temperatures so as to minimize the parasitic reactions, resulting in severe implementation constraints.

  For this type of polymerization, reference can be made to the following work: group transfer polymerization according to the teaching of O.W. Webster "Group Transfer Polymerization", pp. 580-588 in "Encyclopaedia of Polymer Science and Engineering", vol. 7 and HF Mark, Bikales NM, CG Overberger and G. Menges, Publ., Wiley Interscience, New York, 1987, The radical polymerization has the advantage of being easily implemented without excessive conditions of purity are respected and at temperatures equal to or greater than ambient. However, until recently, there has been no radical polymerization process for obtaining (co) polymers with a controlled architecture, in particular block copolymers. Recently, a new process of radical polymerization has developed: it is the so-called "controlled" or "living" radical polymerization (Matyjaszewski, K., Ed., Controlled Radical 2867781 5 Polymerization, ACS Symposium Series 685; Chemical Society: Washington, DC, 1998, and ACS Symposium Series 768, 2001). In these systems, reversible termination or transfer reactions make it possible to maintain the active ends throughout the polymerization, thus giving access to various (co) polymers with a controlled architecture.

  Recently, living radical polymerization processes by reversible addition-fragmentation transfer have been developed. This particular type of polymerization is one of the most appropriate technologies for synthesizing radical block copolymers. In this context, the xanthates RSC (= S) OR 'have been used as transfer agents in the patent applications WO 98/58974, WO 00/75207 and WO 01/042312 of the company Rhodia Chimie to synthesize (co) polymers with controlled architecture.

  An analogous method of preparation by radical polymerization under thermal activation of silicone and organic hybrid block copolymers has also been described in the patent application of the Applicant published under the number WO 02008307. These hybrid copolymers are prepared from a precursor silicone having reactive functions, in particular of the xanthate type, of at least one organic ethylenically unsaturated monomer and of a radical polymerization initiator.

  Therefore, one of the aims of the present invention is to provide a process which makes it possible to obtain isocyanate-functional (co) polymers from (co) polymers having functional groups capable of condensing with the isocyanate functional groups.

  Such functions (hereinafter referred to as 'PH') have a so-called mobile hydrogen and are such that the reaction of the following equation (1) takes place, possibly followed by the reaction of equation (2): -LWH + OCN LYC (O) -N (H) - (1) -LWC (O) -N (H) - + OCN- -LYC (O) -N (C (O) -N (H) -) - (2) ) - where L represents the link with the rest of the molecule; where y represents a chalcogen, (advantageously oxygen or sulfur) or a trivalent nitrogen or phosphorus atom, or even arsenic and even antimony.

  L is advantageously chosen from the single bond (-), the carbonyl groups [-C (= O) -, including NH 2 -C (= O)], the imino groups (> C = N- and C (= N -) - [for example to form amidines, amidoximes (-C (= NOH) -NH2) or a conjugated form of amides]).

  These functions are well known to those skilled in the art and among these are the amino group functions (where y represents> N), which, in addition to the amines and anilines, include the amides [where yf is preceded by by a carbonyl group to give C (= O) -N <] with, as special cases, lactams and ureas, the functions with hydroxyl group [where y represents -O-], which in addition to the alcohol functions, including the phenols, include oximes functions [where y, is preceded by an imino group to give = NO-] oxygenated acid of pKa at least 1, preferably 2, preferably 3, in particular the carboxylic acid functions [where yf is preceded by a carbonyl group to give C (= O) -O-] and the thiol functions.

  Sulfur functions (especially thiols) are however difficult to obtain directly by polymerization, especially radical, because of their propensity to form radicals. These functions are therefore most often obtained indirectly. yr is then carbon with the condition that it carries two electron-withdrawing groups [L is then GEA and yf is C (-GEA ')].

  Mention may also be made of activated methylenes located between two electron-withdrawing groups (denoted GEA and GEA '), such as difluoromethylenes groups, in particular when it is engaged in a perfluoroalkyl, nitrile or carbonyl; yJ is then carbon with the condition that it carries two electron-attracting groups [L is then GEA and yy is C (- GEA ') -].

  This aim and others which will appear later, are achieved by means of a process for obtaining (co) polymers bearing isocyanate functions, characterized in that an initial (co) polymer carrying mobile hydrogen functions with the action of (at least) an isocyanate compound carrying at least two isocyanate functional groups of which at least one is free, most often it is a molecule designated in the technical field by monomer isocyanate ,.

  The functions with mobile hydrogen have already been mentioned above and are well known to those skilled in the art and target any function carrying at least one hydrogen and which is likely to add its hydrogen on the nitrogen of the d function. isocyanate and the rest of the molecule on the carbon of the isocyanate function.

  However, it is preferable that the product thus obtained is stable at temperatures below 100 ° C., preferably at temperatures below 130 ° C. and 150 ° C. In order to have a particularly strong bond, it is preferable that the degradation temperature of the bond thus formed by adding the mobile hydrogen function to the isocyanate function is not degraded before 200 C.

  The most suitable functions for carrying out the invention are alcohol, amine, thiol, acid or even methylene active functions.

  The said isocyanate compounds to be condensed on a mobile hydrogen function are molecules which have at least two functions, (preferably diisocyanates), with free or partially free isocyanate functions or a mixture of isocyanate compounds of which at least one of the compounds has at least one two isocyanate functions, the other isocyanate compounds of the mixture having at least one isocyanate function. In general, when a mixture of isocyanate compounds is used, it contains a majority (more than 50% by weight) of compounds having at least two, preferably more than two, isocyanate functions.

  The isocyanate monomers that can be used for the present invention are the monomers well known to those skilled in the isocyanate field. Mention may in particular be made of monomers formed from polymethylene diisocyanate, such as hexamethylene diisocyanate, or even tetramethylene diisocyanate, or butylene diisocyanate, and 2-methylpentamethylene-1,5-diisocyanate. Mention may also be made of cycloaliphatic monomers such as norbornane diisocyanate, isophorone diisocyanate and 1,3- and 1,4- (bisisocyanatocyclohexane) BICs. Mention may also be made of the compounds of the type LDI (lysinediisocyanate) or LTI (lysinetriisocyanate), as well as NTI (nonyltriisocyanate) or UTI (undecyltriisocyanate).

  Thus, the isocyanate compounds used for the synthesis of the polyisocyanate compounds (most often polyurethanes polyisocyanates) of the invention are advantageously aliphatic isocyanates, whether they are linear, branched, optionally substituted cycloaliphatic or optionally substituted heterocyclic.

  Aromatic monomers can be envisaged, but they are of less interest.

  At this stage of the description, it is probably appropriate to make some 30 semantic reminders.

  According to common usage in chemistry, when a function has given its name to a family of compounds (in other words when a function serves as an eponym for a family of products, as is the case for isocyanates) the aromatic or aliphatic character is defined according to the point of attachment of the function under consideration. When an isocyanate is located on a carbon of aliphatic nature, then it is considered that the isocyanate compound is itself of aliphatic nature. Likewise, when an isocyanate function is attached to the backbone through an aromatic carbon, then the entire monomer will be referred to as aromatic isocyanate.

  To clarify this point, it may be recalled that: Isocyanate function whose attachment point is a link in an aromatic ring is considered as aromatic; Aliphatic is considered to be any isocyanate function whose attachment point (of course nitrogen) is a spi hybridization carbon.

  Among the aliphatic isocyanates the following distinctions may be made: any aliphatic isocyanate function whose attachment point is distant from a ring closest to at most directly to him); is considered secondary, any isocyanate function whose attachment point is carried by a secondary sp3 carbon (that is to say a carbon connected to two carbons and a hydrogen); Tertiary is considered to be any isocyanate function whose point of attachment is carried by a tertiary sp3 carbon (that is to say a carbon connected to three carbons); neopentyl is any isocyanate function whose attachment point is carried by a sp3 carbon, itself carried by a tertiary carbon (that is to say without taking into account the last bond, a carbon connected to three carbons); it is considered as linear any isocyanate function whose attachment point is carried by a methylene sensu stricto (-CH2-), itself carried by an exocyclic and non-tertiary sp3 carbon.

  As regards the monomers, the division by category is done without it being necessary to subject these categories to the torture of Procrustes, that is to say that it is done without difficulty.

  Thus, is reputed: aliphatic any monomer whose all isocyanate functions are aliphatic; aromatic any monomer whose all isocyanate functions are aromatic; any monomer of which at least one function is aliphatic and at least one of which is aromatic; cycloaliphatic any monomer whose all isocyanate functions are aliphatic and at least one of which is cycloaliphatic; Any linear aliphatic monomer whose all isocyanate functions are aliphatic, none of which is cycloaliphatic and at least one of which is linear, or which has at least one polymethylene linkage, free in rotation, and therefore exocyclic, (CH2) n where r represents an integer at least equal to two 2.

  If we detail a little more, the monomeric isocyanates may be: aliphatic, including cycloaliphatic and arylaliphatic (or araliphatic), such as: E as linear aliphatic (or simple), the polymethylene diisocyanate monomers which have one or more polymethylene linkages exocyclic (CH2) 7t where c represents an integer of 2 to 10, advantageously from 4 to 8 and in particular hexamethylene diisocyanate, one of the methylenes may be substituted with a methyl or ethyl radical, as is the case with MPDI (methyl pentamethylene diisocyanate); E as cyclic (or cycloaliphatic) aliphatic: partially "neopentyl" and cycloaliphatic; isophorone diisocyanate (IPDI); As cyclic aliphatic (cycloaliphatic) diisocyanate those derived from norbornane or the hydrogenated forms (hydrogenation of the ring resulting in a diamine ring subsequently subjected to isocyanation, for example by phosgenation) aromatic isocyanates; Araliphatic arylenedialkoylediediisocyanates (such as OCNCH2D-CH2-NCO, part of which is known as linear aliphatic, ie those whose isocyanate function is distant from the aromatic rings of at least two carbons such as (OCN- [CH2] t- cD- [CH2] u-NCO) with t and u greater than 1; É or else aromatic such as toluylene diisocyanate mentioned here for the record, but whose hydrogenated form is considered cycloaliphatic.

  In general, the molecular weight of a monomer does not exceed 300 and is at least 100.

  According to one of the methods of preparation of the compositions according to the invention, the mobile hydrogen compounds are condensed with a di- or even triisocyanate monomer, or with a mixture of two or more of these monomers.

  By way of example, among the diisocyanates which are useful for this method of synthesis, among the aliphatic diisocyanates that may be mentioned are the linear hexamethylene diisocyanate (HDI), the tetramethylene diisocyanate and the 2-methyl pentamethylene 1,5 diisocyanate; cycloaliphatics such as isophorone diisocyanate (IPDI), 2-methylpentanediisocyanate (MPDI), H12-methylene dicyclohexyldiisocyanate (H12-MDI), norbornane diisocyanate (NBDI), bis-1,3- or 4- (isocyanatomethyl) cyclohexane (BIC).

  Condensation is an optionally catalyzed reaction and advantageously carried out at a temperature of between 60 ° C. and 150 ° C., preferably between 70 ° C. and 130 ° C., of an excess of isocyanate compounds with hydroxyl or thiol of polyols or polythiols containing at least one functional group. low mass ester.

  According to the present invention, it is preferable to eliminate the monomers once the functionalization of the (co) polymer carried out. One can also mention the purification using an inert gas such as supercritical CO2 purification which has been patented in the name of RhônePoulenc, see in particular the application published under N EP 0337898, published on Wednesday. 18 October 1989, as well as applications FR 2621037 (A1) and EP 0309364 in the name of the plaintiff's predecessor in law. These two techniques (distillation and use of carbon dioxide) can be optionally coupled.

  Distillation is one of the most suitable methods. Then the excess of diisocyanate monomers is advantageously removed by purification of the reaction medium by a method known to those skilled in the art. It is thus possible to mention the purification of the reaction medium by thin-film vacuum distillation of the diisocyanate monomer at a suitable temperature with the boiling point of the diisocyanate monomer.

  It is also possible to use purification techniques by precipitation or extraction with Soxhlet but these techniques require large amounts of solvent and are therefore not preferred.

  According to another method for preparing the polyisocyanate composition according to the invention, the synthesis consists in reacting the mobile hydrogen functions of the (co) polymer with an excess of compound (s) with more than two isocyanate functional groups or with composition (s) polyisocyanate (s) having an average functionality greater than two, advantageously three, with a ratio of free isocyanate functions (numerator) to mobile hydrogen functions (denominator) (still expressed as NCO / NuH ratio) chosen in the closed range from 2 to 20, preferably 3 to 10, when the isocyanate functions are partially masked to leave a free functionality ranging from 0.8 to 1.5. When there is more free functionality, it is preferable to be in the closed range of 5 to 200, preferably 10 to 100.

  These polyisocyanate compounds may be originally polyvalent monomers such as, for example, LTI (lysinetriisocyanate), as well as NTI (nonyltriisocyanate) or UTI (undecyltriisocyanate).

  However, they are most often derived from the oligomerization techniques of the monomers mentioned above, and therefore contain in their structures biurets and / or isocyanurate and / or carbamate and / or allophanate units or other known structures. those skilled in the art and generally come from a homo or co-oligomerization reaction of the aforementioned monomeric isocyanates on themselves or condensation with other mobile hydrogen molecules. By way of non-limiting examples, mention may be made of the isocyanurate derivatives of hexamethylenediisocyanate (HDI) denoted HDT, HDB biuret derivatives of HDB, isocyanurate derivatives based on isophorone diisocyanate (IPDI) denoted IPDT.

  The fact that the trimers or biurets for functionalizing the polyols thus targeted are not distillable or very difficult to distill can constitute an important inconvenience for the present invention. Also in this case, this technique is particularly advantageous when it is desired to obtain mixed compositions [that is to say a mixture (a + c) of a functionalized (co) polymer according to the present invention (a), and of at least one isocyanate oligomer (c), most often an oligomeric mixture such as those resulting from an oligomerization (exempli gratia trimerization) and / or oligocondensation (exempli gratia a biuretization)]. The mass ratio a / a + c is advantageously at least equal to 1/3, preferably 1/2, and at most equal to 3/4, preferably 2/3.

  It is preferable to use a large excess of monomers over the mobile hydrogen functions. Thus, it is preferable to use amounts of molecule (s) carrying (s) isocyanate function (s) (in particular those designated by those skilled in the art by monomer) such as there are at minus one per mobile hydrogen function to be transformed; a ratio between the molecules carrying isocyanate function (s) [numerator] (for example monomer (s) with isocyanate function) and the number of function (s) with mobile hydrogen (s) expressed in equivalent [denominator] at least equal to 1.

  But it is better that this ratio be much higher. Thus, it is preferable to use at least 2 mol (ie a ratio of 2), preferably at least 4 mol (ie a ratio of 4), more preferably at least 10 mol (a ratio of 10) of compound (s). ) isocyanate (s) per mobile hydrogen function equivalent.

  However, it is unnecessary, although this is not a technical problem, to have stoichiometric excess greater than 50 (that is to say 50 times the stoichiometric amount necessary to graft a molecule of isocyanate compound, especially monomer per function to mobile hydrogen).

  In general, the molar ratio between [the molecules carrying NCO function (s)] [the functions with mobile hydrogens used such as OH (expressed in equivalents)] is generally between 3 and 60, preferably between 5 and 40. When using partially masked monomers the values can be much closer to stoichiometry. When the isocyanate functions are partially masked to leave a free functionality ranging from 0.8 to 1.5, the ratio can range from 1 to 5 times the stoichiometry; which depends on whether the mobile hydrogen function is reacted once or twice.

  It should be emphasized here that a number of the functions with mobile hydrogen are likely to give a condensation with two isocyanate functions. Thus, the alcohol function is capable of initially giving a carbamate and in a second time an allophanate. Similarly, a primary amine function is capable in the first instance of giving a urea and secondly a biuret. Indeed, the reaction product itself has functions (s) to hydrogen (s) mobile (s) on nitrogen. The carboxylic functions can in turn give rise to acylureas (in fact the most common reaction sequence is as follows: the addition of the isocyanate leads to the dissymmetric acid anhydride of the carboxylic acid and of the carbamic acid corresponding to the isocyanate, this anhydride decarboxylates to give the amide of said carboxylic acid and amine corresponding to the isocyanate, a second isocyanate function can then react on the amide to give an acylurea).

  These double condensations are carried out at higher temperature and / or in the presence of suitable catalysts (for example tin salt (s) for allophanation and / or protic acid for biuretization) than the monocondensations which have just been mentioned above. -above. In the case where it is desired to carry out these double condensations, which have the advantage of increasing the isocyanate functionality, a stoichiometric excess of the same value as those indicated above, but with a reaction involving two monomers and no longer one.

  According to the present invention, it is preferable to eliminate the monomers once the functionalization of the (co) polymer carried out. Distillation is one of the most suitable methods. One can also mention the purification using an inert gas such as purification by supercritical CO2 which has been patent in the name of Rhone-Poulenc, the predecessor in law of the Applicant. These two techniques can be optionally coupled.

  It is also possible to use precipitation purification or Soxhlet extraction techniques, but these techniques require large amounts of solvent and are therefore not preferred.

  According to one of the possible implementations of the present invention, it is possible to use a partially masked monomer, that is to say masked so as to leave only one free isocyanate function, at least statistically.

  In these cases, it will then be possible to use the simple stoichiometric amount to functionalize the mobile hydrogen functional (co) polymer and thereby obtain a masked isocyanate isocyanate (co) polymer.

  It is appropriate to return to the (x) (co) polymer (s) bearing functional hydrogen functional, and to detail some of those that are preferred.

  According to one of the preferred embodiments of the present invention, star (co) polymers are (co) polymers resulting from a polyfunctional molecule [in general, whose molecular weight at most equal to 500 (1 significant number), advantageously to 300 and at least equal to 100 (2 significant digits)], in particular tri-, tetra- or penta-functional, [function (s) which may be derived from polymerization control agents] on which the units have been grafted by polymerization or polycondensation (in this case, the functions of the polyfunctional molecule are advantageously functions with mobile hydrogen).

  Thus, in the latter case, it is possible, by using polycondensable functional molecules for example chosen from lactones, lactams, or cyclic ethers, including alkene oxides, especially ethylene, to grow branches from a function carrying mobile hydrogen (most often alcohol, or hydroxyl) itself carried by said polyfunctional molecule, (especially tri-, tetra- or penta-functional) forming the core of the star.

  Thus, the mobile hydrogen-functional (co) polymer is advantageously a star-type (co) polymer capable of being obtained by oligo- or polycondensation of polycondensable molecules, advantageously chosen from lactones, lactams, or ethers. cyclic, on the functions of a polyfunctional molecule forming the core of the star and grow arms therefrom from each function [advantageously carrying mobile hydrogen (most often alcohol, or hydroxyl)] said polyfunctional molecule, ( especially tri-, tetra- or penta-functional).

  These star (co) polymers targeted by the present invention are better described below.

  According to the present invention, it is desirable that the mass of such polyol or polythiols obtained by condensation (polyesters and / or polyethers) which will react with the isocyanates for the synthesis of the polyisocyanate polyurethanes which are the subject of the invention is greater than or 200, preferably 250, preferably 300 (two significant digits) less than 5000, preferably less than 3000, preferably 2000.

  These poly (thi) ols contain at least one ester function and possibly other functions ethers, thioethers, thioesters ... Their synthesis is known in the art.

  By way of example, mention may be made, as a method for synthesizing poly (thi) ols polyesters: the esterification, optionally catalyzed, of a low-molecular polyol or polythiol having at least 3 hydroxyl functions and / or thiols with a alcoholic acid and / or thiol acid; the optionally catalyzed transesterification of a low-molecular polyol and / or polythiol having at least 3 hydroxyl and / or thiol functions with a hydroxy and / or thiol alkyl ester, such as the hydroxy or thiolo carboxylic acid esters; and the optionally catalyzed reaction of a low-molecular polyol and / or polythiol having at least 3 hydroxyl and / or thiol functions on a lactone or thiolactone; or the combination of at least two of the three methods mentioned above.

  To obtain polyols or polythiols of small masses, it limits the rate of conversion of the reaction used (esterification transesterification ...) or one works with molar ratios (acid and / or ester and / or lactone and / or thiolactone / OH ) greater than 1, generally between 2 and 50, preferably between 4 and 20. The reaction medium is generally purified by removal of the hydroxy monomers and / or thioalkyl acid, hydroxy and / or thioalkyl ester or lactone and / or thiolactone according to a suitable method, liquid extraction, precipitation or distillation.

  The ester monomers and lactones can thus be separated by thin-film distillation under vacuum at a temperature appropriate to the boiling point of the monomer.

  By hydroxy monomers or thioalkylesters or acids is meant compounds which contain at least one hydroxy or thiol function attached to an alkyl chain which carries at least one acid function, preferably carboxylic or ester.

  Exemplary hydroxy or thioalkyl acid compounds include glycolic acid, lactic acid, pivalic hydroxy, 10-hydroxy-decanoic acid, 12-hydroxydodecanoic acid, 12-hydroxystearic acid, 4-hydroxypimelic acid; 5-hydroxyazelaic acid, cholic acid, thioglycolic acid, mercaptopropionic acid ...

  As examples of hydroxy or thioalkyl ester compounds, mention may be made of methyl, ethyl, isopropyl butyl esters, hydroxy or thioalkyl acid mentioned above.

  Light esters which allow for easier transesterification reaction will be preferred.

  As examples of lactones, there may be mentioned caprolactone, butyrolactone, γ-valerolactone, γ-octanoic lactone, ahydroxylactone, γ-butyrolactone, acetylbutyrolactone, homocysteine thiolactone.

  Such products are well known and may be mentioned by way of example, the product sold under the trade name Capa 316 obtained by reaction of ε-caprolactone on pentaerythritol and sold by the company Solvay.

  The polyols may also contain other functions such as amide functions in that the lactone opening compound is a compound having amine and alcohol functional groups or only amine functions. By way of examples of such compounds, mention may be made of tris hydroxymethyl aminomethane which, by reaction with a lactone, will give polyols containing at least one amide function and one ester function.

  According to another preferred embodiment, the (co) polymers to be functionalized are advantageously chosen from the (co) polymers known as (co) polymers with controlled architecture carrying mobile hydrogen functions as defined above.

  These (co) polymers carrying mobile hydrogen functional groups have been defined above and among these may be mentioned: • statistical (co) polymers with low dispersity; The block (co) polymers of which at least one of the blocks carries mobile hydrogen functional groups; when they are triblock or multiblock advantageously these (co) block polymers are either: consisting of the sequence of vinyl homopolymers, advantageously acrylic, of different nature ABC, the number of block sequences being not limited, consisting of a sequence of acrylic heteropolymers of different nature ABC, the block sequences being prepared from at least two different monomers and their number being not limited, consisting of the two types of preceding sequences, namely the sequence of block sequences prepared by polymerization of a single double bonded monomer, and block sequences prepared by copolymerization of at least two different monomers; Hyper-branched (co) polymers, sometimes referred to as "hyper-branched" Anglicism; Star (co) polymers; Microgel (co) polymers; The comb (co) polymers.

  These (co) polymers with controlled architecture, are most often made using a living polymerization technique, preferably radical, such as that described in the introduction of the present application.

  Thus, the techniques used can notably be those described in the following documents: the processes of applications WO 98/58974, WO 00/75207 and WO 01/42312 which implement controlled radical polymerization by control agents of the type xanthates, the radical polymerization process controlled by dithioester type control agents of the application WO 97/01478, the process of the application WO 99/03894 which uses a polymerization in the presence of nitroxide precursors, the radical polymerization process controlled by dithiocarbamate type control agents of the application WO 99/31144, the method of the application WO 96/30421 which uses a radical polymerization by atom transfer (ATRP), the process of radical polymerization controlled by agents of Iniferter type control according to the teachings of Otu et al., Makromol. Chem. Rapid. Commun., 3, 127 (1982), the method of controlled radical polymerization controlled by degenerative transfer of iodine according to the teaching of Tatemoto et al., Jap. 50, 127, 991 (1975), Daikin Kogyo Co Ltd Japan and Matyjaszewski et al., Macromolecules, 28, 2093 (1995), the radical polymerization process controlled by tetraphenylethane derivatives, disclosed by D. Braun et al. In Macromol. Symp.

  111, 63 (1996), or the process of radical polymerization controlled by organocobalt complexes described by Wayland et al. In J. Am.Chem.Soc. 116, 793 (1994).

  Nevertheless, according to the present invention, among the techniques described, it is preferred to use the techniques developed by the Applicant in which the polymerization control agent carries at least one function selected from that comprising the SC sequence (= S and especially dithioesters, dithiocarbazates, dithiocarbamate, xanthates, sequence products -SC (= S) -ON <described in USN 6,667,376B and WO 03 082928.

  The control agent is advantageously xanthates (formula (I) in which R is hydrocarbyloxyl). According to one embodiment of the present invention, the (co) polymer carrying a mobile hydrogen function is derived from a radical living polymerization of which control agent, corresponds to formula (I), S = C (R) -S-formula (I) wherein i; represents: an alkyl, acyl, aryl, alkenyl or alkynyl group; a carbon cycle, saturated or not, optionally aromatic; a heterocycle, saturated or unsaturated, optionally aromatic; or a (co) polymer chain, and R represents: (i) an alkyl, haloalkyl, perfluoroalkyl, alkenyl or alkynyl, acyl, aryl, arylalkyl, arylalkenyl or arylalkynyl group, or a carbon ring or a heterocycle, or alternatively a polymer chain; (ii) a radical -ORa, in which Ra denotes a group chosen from: an alkyl, haloalkyl, perfluoroalkyl, alkenyl, alkynyl, acyl, aryl, arylalkyl, arylalkenyl or arylalkynyl group, or a carbon ring or a heterocycle, or a polymer chain; a group -CRbR PO (ORd) (ORe), in which: Rb and Rc each represent, independently of each other, a hydrogen atom, a halogen atom, a perfluoroalkyl group or a carbon cycle or a heterocycle, or else a group -NO2, -NCO, -CN, or a group chosen from -Rf, -SO3Rf, -ORf, -RSf, -NRfR9, -000Rf, -CONRfR9, or S03Rf, wherein Rf and R9 are each independently an alkyl, alkenyl, alkynyl, aryl, aryl, arylalkyl, arylalkenyl, or arylalkynyl group; Or Rb and Rc form together with the carbon to which they are attached, a group C = O or C = S, or a hydrocarbon ring or a heterocycle; and E Rd and Re each represent, independently of one another, a radical corresponding to one of the definitions given above for the Rf group; or Rd and Re together form a hydrocarbon chain comprising from 2 to 4 carbon atoms, optionally interrupted by a group -O-, -S-, or NRh-, where Rh is one of the definitions given above for the group Rf; a group NR'Ri, where R 'and Ri are defined below.

  (iii) a group NR'RR, in which: R 'and Ri represent, independently of one another, a radical chosen from an alkyl, haloalkyl, alkenyl, alkynyl, acyl, ester, aryl, arylalkyl, arylalkenyl or arylalkynyl group, or a carbon cycle; or R 'and R 1 together form a hydrocarbon chain comprising from 2 to 4 carbon atoms, optionally interrupted by a group -O-, -S-, or NR "-, where R" corresponds to one of the definitions given below. above for the Rf group, said hydrocarbon chain advantageously forming a 5-membered ring with the nitrogen to which R 'and R 1 are attached, the radicals R' and R 1 preferably inducing an electron-attracting effect or a delocalization effect vis-à-vis the electronic density of the nitrogen atom to which they are bonded.

  Throughout the present description, it is meant to cover, by the term "alkyl" group, a linear or branched, saturated hydrocarbon radical which may optionally include one or more saturated aliphatic ring (s). Within the meaning of the invention, the alkyl groups can have up to 25 carbon atoms, and they preferably contain from 1 to 12 carbon atoms, and preferably from 1 to 6 carbon atoms.

  In particular, an alkyl group may also designate, within the meaning of the invention, a cycloalkyl group, that is to say a cyclic saturated hydrocarbon radical, preferably having from 3 to 10 carbon atoms.

  For the purposes of the invention, an "alkoxy (Ie)" group refers to a radical -OAIk, where Alk denotes an alkyl group as defined above.

  For the purposes of the invention, the term "haloalkyl" group is understood to mean an alkyl radical as defined above and substituted with at least one halogen atom, where the term "halogen atom" designates here, as in all of the description, a fluorine, chlorine, bromine or iodine atom, preferably a fluorine or chlorine atom, and preferably a fluorine atom. The "haloalkyl" groups of the invention can thus be, for example, "perfluoroalkyl" groups, that is to say, within the meaning of the invention, groups corresponding to the formula -CH2CnF2n + 1, where n represents an integer ranging from from 1 to 20.

  Moreover, an "alkenyl" group, in the sense used in the present description, denotes a linear or branched unsaturated hydrocarbon radical having at least one C = C double bond. The alkenyl groups of the invention can have up to 25 carbon atoms and preferably comprise from 2 to 12 carbon atoms, and preferably from 2 to 6 carbon atoms.

  Similarly, the term "alkynyl" group means an unsaturated hydrocarbon radical, linear or branched and having at least one C = C triple bond. The alkynyl groups of the invention generally have from 2 to 25 carbon atoms, and they preferably comprise from 2 to 15 carbon atoms, and preferably from 2 to 6 carbon atoms.

  For the purposes of the invention, an "acyl" group denotes a group of formula -C (= O) -B, where B denotes a linear or branched, saturated or unsaturated hydrocarbon-based chain containing from 1 to 25 carbon atoms. carbon atoms, and which may in particular be an alkyl, alkenyl or alkynyl group as defined above.

  By "ester" group within the meaning of the invention is meant a C (= O) -OB group, where B denotes a linear or branched, saturated or unsaturated hydrocarbon-based chain containing from 1 to 25 carbon atoms, and may in particular be an alkyl, alkenyl or alkynyl group as defined above.

  For the purposes of the invention, a "carbon-based ring" radical denotes a saturated, unsaturated or aromatic cyclic group, in particular of cycloalkyl, cycloalkenyl or cycloalkynyl type, which is optionally substituted and which has from 3 to 20 carbon atoms. A radical of the "heterocycle" type refers to such a carbon ring interrupted by at least one heteroatom chosen for example from N, O or S. An "aryl" group designates for its part, within the meaning of the invention, a group mono- or polycyclic aromatic having generally from 5 to 20 carbon atoms, and preferably from 6 to 10 carbon atoms. Thus, it can for example be a phenyl group, 1- or 2-naphthyl, pyridinyl or tolyl (but not benzyl). According to a particular variant, a "aryl" group within the meaning of the invention can integrate one or more heteroatoms such as sulfur, oxygen, or nitrogen. In this particular case, the "aryl" group within the meaning of the invention denotes a mono- or polycyclic heteroaromatic group. Of course, said aryl group carries the free bond on an intracyclic atom (in the case of carbon this carbon is obviously of sp2 hybridization) of the aromatic ring. The "arylalkyl", "aralkenyl" and "aralkynyl" groups within the meaning of The invention is, respectively, alkyl, alkenyl and alkynyl chains substituted by an aryl group as defined above. In other words, the "arylalkyl", "aralkenyl" and "aralkynyl" groups within the meaning of the invention are respectively groups of the Ar-Ra-type, in which Ar represents an aryl group and where the groups of the type Ra represent respectively an alkylene, alkenylene or alkynylene chain.

  The various radicals may optionally be interrupted by one or more heteroatoms chosen in particular from O, S, and N, Si, or by groups - (C = O) -, - (C = S) -, -SO2-, -SO - or secondary or tertiary amines, and they may be substituted by any type of group which is not likely to interfere with the polymerization reaction or to lead to parasitic reactions between the compounds in the presence, and in particular by one or more identical groups or different chosen from a halogen atom, a silyl group, a group -OH, alkoxy, -SH, thioalkoxy, -NH2, mono- or di-alkylamino, -CN, -000H, ester, amine, or perfluoroalkyl, said substituents possibly being interrupted by heteroatoms. It is skilled in the art to choose the nature of the various groups and substituents present in the compounds used to avoid any unwanted side reaction.

  Thus, it is possible to implement a process comprising at least one step having the following characteristics: a controlled radical polymerization leading to the production of a functionalised (co) polymer useful as a control agent in a reaction of controlled radical polymerization, said step being conducted by contacting: ethylenically unsaturated monomeric molecules, a source of free radicals, and at least one control agent as defined above.

  To produce the (co) polymers having several blocks, it is possible to start with a step as above which can be designated by step a) and to have it followed by a step of the same characteristic but where the control agent will be the 2867781 21 (co) polymer obtained in the first step carrying the appropriate control functions and whose formula E. is mentioned above.

  Thus, following step (a), a step (b) of controlled radical polymerization, or several successive controlled radical polymerization steps, is carried out, said step (s) each consisting in carrying out a controlled radical polymerization leading to obtaining a functionalized block copolymer useful as a control agent in a controlled radical polymerization reaction, said step or steps being carried out by bringing into contact: ethylenically unsaturated monomeric molecules different from those implemented in the preceding step, a source of free radicals, and the functionalized (co) polymer derived from the preceding step.

  It is understood that at least one of the polymerization steps (a) and (b) defined above leads to the formation of the anchoring block, that is to say the block comprising the functions with mobile hydrogen (s) ( s), and that another of the polymerization steps of steps (a) and (b) leads to the formation of another block. It should be noted in particular that the ethylenically unsaturated monomers used in steps (a) and (b) are chosen from suitable monomers to obtain a block copolymer as defined above.

  In general, the polymerization steps (a) and (b) are carried out in a polar solvent medium such as tetrahydrofuran, dioxane, symmetrical ethers or non-esters, or even ketones and nitriles. The alcoholic or hydroalcoholic medium can be used but it then involves a change of solvent to go to the condensation stage with isocyanates for fear of reaction of the latter with water (formation of biuret) or with alcohols ( formation of carbamate or even allophanate).

  One advantage of the polymerization control functions above (E-) lies in the possibility of transforming them into SH function according to techniques known per se (for example those described in the PCT application in the name of the applicant published under WO02 / 090424). These functions are then added to those carried by the monomers used thus increasing inexpensively the functionality of the (co) polymer thus produced and used for the present invention. This is particularly true for the (co) polymers resulting from polymerization (s) at several sites of chain propagation, such as stars, microgels, hyperbranched, combs.

  Such (co) polymers having at least one, advantageously two), thiol function and at least three, preferably five, preferably six functions chosen from those in which Y is oxygen or nitrogen (see the specific functions mentioned, see the passages where the functions with mobile hydrogen are described), are particularly interesting. The thiol (-S-H) functions of these (co) polymers give, by reaction on the isocyanate functions, thiocarbamate functions (-S-CONH-).

  The monomers useful for preparing the (co) polymers with controlled architecture are advantageously chosen from monomers exhibiting at least one vinylic unsaturation, advantageously activated. Among these monomers, it is possible to distinguish the monomers carrying mobile hydrogen functional groups, the monounsaturated monomers that do not carry mobile hydrogen functions, the doubly unsaturated or polyunsaturated monomers that are useful for creating branches, stars and / or microgels.

  Monomers of acrylic nature are the most commonly used.

  Monounsaturated monomers that do not carry mobile hydrogen functional groups are well known to those skilled in the art, among those that may be mentioned: esters of primary, secondary or tertiary alcohols of acrylic or methacrylic acids, the alcohols being aliphatic, cycloaliphatic or araliphatic beings. By way of example, mention may be made of n-butyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl acrylate and methyl methacrylate. tert-butyl methacrylate, etc., styrene, acrylic nitriles, vinyl ethers, vinyl esters, vinyl amides (N-vinyl formamide, N-vinyl acetamides), especially vinyl lactams (N-vinyl pyrrolidone).

  Some of these monomers may be latent vectors of mobile hydrogen functions. Thus, after polymerization, the hydrolysis of the acrylates gives carboxylic functions; that of acrylic nitriles amides or carboxylic acids; that of vinylamides of amines; that of the vinyl esters gives alcohols.

  Among the monomers carrying mobile hydrogen functional groups, mention may be made of: the amides of acrylic and methacrylic acids or, more generally, the amides corresponding to unsaturated carboxylic acids, the amide carrying at least one hydrogen, so it is possible acrylamide, methacrylamide, the amides of said acids, preferably not forming cyclic imide; the hydroxyalkyl esters of acrylic and methacrylic acids (mention may also be made of the monoacrylates or monomethacrylates of ethylene glycol (such as HEMA), propanediol, butanediols, one can also envisage monomethacrylates or triol monoacrylates, such as glycerol; the aminoalkyl esters of acrylic and methacrylic acids; acrylic and methacrylic acids; the functions with a mobile hydrogen are preferably the hydroxyl functions, and in particular primary or secondary alcohols, or primary or secondary amines.

  The doubly unsaturated or polyunsaturated monomers are those known to crosslink. Among these, we may mention: The monomers belonging to these families are divinylbenzene and derivatives of divinylbenzene, vinyl methacrylate, methacrylic acid anhydride, allyl methacrylate, ethylene glycol dimethacrylate, phenylene dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol 200 dimethacrylate, polyethylene glycol 400 dimethacrylate, butanediol 1,3-dimethacrylate, 1,4-dimethacrylate, butanediol, hexanediol 1,6-dimethacrylate, dodecanediol 1,12-dimethacrylate, glycerol 1,3-dimethacrylate, diurethane dimethacrylate, trimethylolpropane trimethacrylate. For the family of multifunctional acrylates, there may be mentioned vinyl acrylate, epoxy bisphenol A diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol 600 diacrylate, ethylene glycol diacrylate, diacrylate diethylene glycol, triethylene glycol diacrylate, tetraethylene glycol diacrylate, ethoxylated neopentyl glycol diacrylate, butanediol diacrylate, hexanediol diacrylate, aliphatic urethane diacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate ethoxylated, propoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, aliphatic urethane triacrylate, trimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate. As regards the vinyl ethers, there may be mentioned vinyl crotonate, diethylene glycoldivinyl ether, 1,4-butanediol divinyl ether, triethylene glycol divinyl ether. For the allyl derivatives, there may be mentioned diallyl phthalate, diallyldimethylammonium chloride, diallyl maleate, sodium diallyloxyacetate, diallylphenylphosphine, diallylpyrocarbonate, diallyl succinate, N, N'-diallyltartardiamide, N, N- diallyl-2,2,2-trifluoroacetamide, allyl ester of diallyloxy acetic acid, 1,3-diallylurea, triallylamine, triallyl trimesate, triallyl cyanurate, triallyl trimellitate, triallyl-1,3,5- triazine-2,4,6 (1H, 3H, 5H) -trione. For the acrylamido derivatives, there may be mentioned N, N'-methylenebisacrylamide, N, N'-methylenebismethacrylamide, glyoxal bisacrylamide, diacrylamido acetic acid. As regards the styrenic derivatives, there may be mentioned divinylbenzene and 1,3-diisopropenylbenzene. In the case of diene monomers, there may be mentioned butadiene, chloroprene and isoprene.

  As multiethylenically unsaturated monomers, N, N'methylenebisacrylamide, divinylbenzene and ethylene glycol diacrylate are preferred.

  The types and amounts of multiethylenically unsaturated monomers used according to the present invention vary depending on the end application.

  The polycondensates, and especially the urethanes obtained from these (co) star polymers and microgels are most often characterized by a viscosity which for such (co) polymers can be considered as low, namely a viscosity at most equal at 100 000 mPa.s at 25 C and 100% dry extract and in general at least 1000, most often at 5000 mPa.s. Most often, the preferred ones have a viscosity of between 7,500 and 50,000 mPas at 25 ° C for a solids content of 100%. They exhibit a functional isocyanate function (free or masked) at least equal to 3, preferably greater than 3, more preferably greater than or equal to 4.

  In the context of the present invention, the functionality is deduced from the content of isocyanate function equivalent per gram of dry extract and the average weight Mw by weight, which makes it possible to calculate the number of isocyanate equivalents for an average mass Mw. calculated by gel permeation. Value that is the functionality.

  The polyisocyanate structures that are the subject of the invention can be defined by their process of production.

  In addition to those resulting from the condensation of star polycondensate isocyanate such as CAPA, mention must be made of polyisocyanate (co) polymers having statistically at least one, advantageously at least two, preferably at least three function (s) chosen from thiocarbamate functions (-S-CO-NH- resulting from the reaction of a thiol function on an isocyanate function) and thioallophanate (-S-CO-N (-CO-NH- ) - and secondly at least 2, advantageously at least 3, preferably at least 5, more preferably at least 7, functions selected from those resulting from reaction (s) of one, two or more functions 2867781 Isocyanates with a function chosen from functional groups with a mobile hydrogen other than thiol, in particular from hydroxyl and amino functions, Thus these polyisocyanate (co) polymers have at least one thiocarbamate function (-SC (= O) -NH- ) or thioallophanate and at least three, at least five functions, preferably at least seven functions selected from urea functions (lato sensu that is to say including in particular biuret functions) carbamate (-O-C (= O) -NH-) and allophanate. The functionality is calculated using the number average mass (Mn) and can of course be fractional.

  The most common polyisocyanate structures which are the subject of the present invention can be written as follows: A (NCO) x with A the remainder of a polyisocyanate (co) polymer, preferably polyurethane, containing at least one ester functional group and without its functions isocyanates, and x at least equal to 3 and at most equal to 30, preferably between 4 and 15.

  Some linear structures are schematized as follows: (R2) qC- (R1) - [CH2- [OC (O) - (CH2) n] mOC (O) -NH-R-NH-C (O) -O- [ (CH2) nC (O) -O] mCH2-C- (R1) - (R2)] a-R2 with: a is between 0 and 5 with a may be 0 or 5 (closed range), R2 , identical or different (but in general they are identical), is equal to [OCN-R-NH-C (O) -O - [(CH2) nC (O) -O] m -CH2-, RI an alkyl chain linear or branched at least one carbon atom optionally interrupted by heteroatoms (O, S, or N) or R1 is equal to R2, n is at least 1 and in general at most 10, advantageously 6, m is at least 1 and in general at most 10, preferably 5 g is 2.

  The branched structures are schematized as follows: (R2) q- (R1) -C- [RC (R1) - [RC-R1- (R2) q]] p- [R- [C-R1- [RC- ( R1) (R3) - [RC- (R1) (R2) 2] s] rRCR 1- (R2) q with: 2867781 26 - R is equal to CH2- [OC (O) - (CH2) n1m-OC ( 0) -NH-R-NH-C (O) -O- [(CH2) nC (O) -O] m -CH2-, - p is between 1 and 5, - s is 2 when R3 is equal to nothing and s is 1 when R3 is equal to R2, where r is between 1 and 3.

  As described above, the products of the invention are obtained by optionally catalyzed reaction at a temperature of between 60 and 150 ° C., preferably between 70 and 130 ° C., of an excess of isocyanate compounds with hydroxyls or thiols. polyols or polythiols containing at least one low molecular weight ester function. The excess of diisocyanate monomers is removed by purification of the reaction medium by a method known to those skilled in the art. It is thus possible to mention the purification of the reaction medium by thin-film vacuum distillation of the diisocyanate monomer at a suitable temperature with the boiling point of the diisocyanate monomer.

  The condensations with the mobile hydrogen functions can be catalyzed by catalysts known to those skilled in the art, among which include derivatives of tin (DBTL), bismuth, zinc, etc. Mention may in particular be made of tin dibutyldilaurate or, more exactly, dibutyltin dilaurate, zinc dioctoate and bismuth acetate.

  These catalysts are obviously usable for all types of mobile hydrogen functions.

  The polyisocyanate composition (often based on polyisocyanate polyurethanes) obtained after distillation generally contains a level of diisocyanate monomers of less than 5%, preferably less than 1%.

  The vacuum distillation temperatures of the diisocyanate monomers are generally between 80 and 250 ° C., preferably between 110 and 200 ° C.

  According to another preferred embodiment of the present invention, it is possible to functionalize block (co) polymers whose syntheses have made progress during the last luster.

  The star (co) polymers are advantageously prepared from a first (co) polymerization from a seed of monomers, at least one of which has at least two radical-crosslinkable double bond functions, and optionally another monomer. carrying a mobile hydrogen function, the latter being free or latent, followed by (co) polymerization with double-bonded monomers, at least one of which carries free or latent mobile hydrogen functional groups, 2867781 The number of functions per acrylic polymer chain is at least one and at most 50, preferably between 2 and 20.

  The molecular weights of the polymer chains are on average between 500 and 20,000, preferably between 1,000 and 10,000.

  The isocyanate compounds used to functionalize the acrylic (co) polymers carrying mobile hydrogen functional groups are compounds generally comprising at least two isocyanate functional groups with an aliphatic and / or cycloaliphatic and / or aromatic skeleton.

  The functionalization of these (co) block polymers is carried out according to the same principles as before and with the same preferences. However, we can resume in details.

  One method of synthesis consists in reacting the mobile hydrogen functions of the (co) polymer with excess diisocyanates in a ratio of isocyanate functions to functions with mobile hydrogen (still expressed as NCO / NuH ratio) of between 1.5 and 100%. preferably between 2 and 50.

  The choice of this ratio is strongly related to the functionality of the (co) polymer to be functionalized, defined as the average number of mobile hydrogen functions per polymer chain. To prevent cross-linking of the polymer chains with each other and to preserve manipulable compounds, the NCO / NuH ratio is optimized. Thus, the higher the functionality, the higher the NCO / NuH ratio. Conversely, to functionalize (co) polymers with low functionality, lower NCO / NuH ratios will be retained.

  The reaction is carried out at a temperature of between 0 and 300 ° C., preferably between 10 and 200 ° C. and more precisely between 20 ° and 150 ° C. for a reaction time of between a few minutes and a few hours, depending on the reactivity of the compounds involved and the possible presence of a catalyst.

  In the case where the mobile hydrogen functions are primary or secondary amines, a catalyst is generally not necessary. In the case where the functions with a mobile hydrogen are hydroxyl functions, it is possible to use catalysts conventionally used in polyurethane synthesis reactions. Examples of non-limiting examples are tin derivatives such as dialkyldiacyltin (dibutyldilaurate or dibutyldi-tin acetate), zinc derivatives such as zinc octoate, bismuth derivatives or zirconium well known in polyurethane chemistry and sold by King Industry, ATOFINA ...

  The amount of catalyst used is generally between 100 ppm and 1% of catalyst relative to the amount of mobile hydrogen compounds involved so that the amount of catalyst in the final product is as low as possible.

  The diisocyanate used in excess is generally separated from the functionalized (co) acrylic polymer by a purification process. The latter is generally based on a distillation of the diisocyanate monomers under high temperature vacuum in a thin film apparatus.

  Other purification processes based on other separation techniques may be used when the monomeric diisocyanate has a high boiling point. By way of example, mention may be made of the separation processes by gel permeation chromatography, by filtration on organic or inorganic membranes separating the high molecular weight compounds from the low masses, the selective crystallization processes in a solvent compatible with the isocyanate functions present on the monomer and the functionalized (co) polymer, purification processes by extraction with an inert gas such as, for example, purification by carbon dioxide in the supercritical state.

  The preferred purification technique is distillation.

  If we return to the synthesis of (co) block polymers, it should be noted that this technique, although new, is well known to those skilled in the art and in particular can be referred to the methods described in the different patents and cited below.

  In general, it is preferred that the block copolymers used according to the invention come from a controlled radical polymerization process employing, as a control agent, one or more compounds chosen from dithioesters, thioethers-thiones, dithiocarbamates, and xanthates. In a particularly advantageous manner, the block copolymers used according to the invention are derived from a controlled radical polymerization carried out in the presence of control agents of the xanthate type.

  According to a preferred embodiment, the block copolymer used can be obtained according to one of the methods of applications WO 98/58974, WO 00/75207 or WO 01/42312 which implement controlled radical polymerization by control agents. xanthates type, said polymerization can be carried out in particular by mass, solvent avoiding solvents capable of reacting with the free isocyanate function.

  In general, it is preferable that said (co) polymer bearing isocyanate functional groups thus obtained has an isocyanate function content of at least 1%, advantageously at least 2%, preferably at least 28%. 4% by mass (the mass of the isocyanate function, whether free or masked, is known for this type of calculation equal to 42). It is also desirable for said (co) polymer bearing isocyanate functional groups to have an isocyanate content of at most 20, advantageously 15, preferably 10% by weight.

  However, the risk is that there are few isocyanate functions with respect to the crosslinking function used. This is the reason why these (co) polymers can either be cross-linked by means of polyols or polyamides of low molecular weight, that is to say polyols or polyamines, or even polysulfides, polyhydrogenosulphides of molecular mass at most equal to 1000, preferably 500, more preferably 300.

  Another possibility is to reduce the size of the (co) polymer, so it is preferable that the initial (co) polymer bearing functions with mobile hydrogen has a mass itself measured by gel permeation chromatography at most equal to 50,000. preferably, preferably at 10,000, more preferably at 5,000. The (co) polymer bearing isocyanate functional groups itself has a value which is advantageously greater than 1,000, preferably 1,500 and at most 60,000, advantageously at most equal to 12,000, more preferably at most 6,000.

  In order to overcome the lack of isocyanate functionality of the (co) polymers thus obtained, it is possible to add isocyanate compositions which are usually commercially available and whose isocyanate function content is at least 15% by weight, preferably at least 20%. % mass.

  The mixture of these two isocyanate sources is advantageously such that the isocyanate content (expressed as -N = C = O, in masked, free or mixed form) of all the isocyanate functional carriers is at least equal to 5. %, preferably 8%, more preferably 10%.

  Thus, the present invention relates to coating compositions which comprise: a) at least one (co) polymer according to the invention, b) at least one di or polyfunctional compound with a mobile hydrogen, advantageously a polyol, and optionally c) a composition conventional isocyanate, the amounts of compound a) and compound b) being such that their mixture has an isocyanate content of at least 5%, advantageously 8%, preferably 10%.

  It is desirable for said di or polyfunctional mobile hydrogen compound to have a low molecular weight of at most 1000, advantageously 500, preferably 300.

  Such a composition for coatings (paint, varnish, adhesive, etc.) also comprises a condensation catalyst.

  Such a composition may also comprise a pigment, and in particular titanium dioxide.

  The following nonlimiting examples illustrate the invention.

  Method of dosing the isocyanate functions of a polyisocyanate.

  The NCO titre assays are carried out according to the standardized method known as the dibutylamine (DBA) assay. To a sample of known mass of polyisocyanate solution to be assayed, a known amount of dibutylamine is added.

  The solution is diluted with isopropanol or a non-reactive solvent of the (co) polymer to be titrated. The reaction is stirred for 10 minutes. The excess of DBA is then determined by a hydrochloric acid solution. The difference between the amount of DBA dosed and the amount of DBA added corresponds to the rate of NCO functions reacted with the DBA.

  Al Synthesis of Star-Functioning High-Function Polyisocyanate Polyurethanes Example A-11 Synthesis of Polyisocyanate Polyisocyanate Based on HDI and CAPA 316 (NCO / OH Ratio = 5) CAPA 316 is a polyester of molecular weight (MW) 1000 obtained by reaction epsilon caprolactone on pentaerythritol. It is sold by SOLVAY.

  3 g of hexamethylene diisocyanate (HDI) (ie 3.54 moles) are added successively under nitrogen at 300 ° C. to a nitro reactor inert with nitrogen, equipped with agitation, a condenser and an addition funnel. NCO) and 193 g of CAPA 316 (ie 0.710 moles of hydroxyl functions). The temperature of the reaction medium is raised to 80 ° C. and the mixture is stirred for 4 hours. The NCO titre of the reaction medium is 0.606 moles per 100 g for a theory of 0.74 moles.

  The reaction mixture is then purified by distillation under high vacuum to remove the monomeric HDI under 0.1 mbar at 160 ° C.

  The amount recovered is 269 g.

  The viscosity is 29,970 mPa.s at 25 ° C. and the NCO titre of the purified product is 0.176 mol per 100 g, ie an NCO weight titre of 7.4%. The product is translucent.

  The viscosity at 90% solids content in n-butyl acetate is 4900 mPas at 5 ° C. and 1100 mPas at 80% solids content and 366 mPa s at 70% solids content.

  Example A-2 / Synthesis of Polyisocyanate Polyisocyanate Based on HDI and CAPA 316 (NCO / OH Ratio = 10) The procedure is as for Example A-1 while working with an NCO / OH ratio of 10 instead of 5.

  The characteristics of the final product are: - NCO title: 0.17 moles of NCO per 100 g, ie a weight titre of 7.5%; Viscosity at 25 ° C: 14,000 mPa s; - Translucent product.

  The viscosity at 90% solids content in n-butyl acetate is 2 220 mPas at 25 ° C. and 600 mPas at 80% solids content.

  EXAMPLE A-3 / Synthesis of Polyisocyanate Polyisocyanate Based on HDI and CAPA 316 (NCO / OH Ratio = 10) The procedure is as for Example A-2 while working with an NCO / OH ratio of 10 and with a quantity of HDI of 500 g.

  The characteristics of the final product are: NCO title: 0.217 moles of NCO per 100 g with a weight titre of 9.11%; Viscosity at 25 ° C: 14,540 mPa s; - Translucent product.

  EXAMPLE A-4 / Synthesis of Polyisocyanate Polyisocyanate Based on HDI and CAPA 316 (NCO / OH Ratio = 5) The procedure is as for Example A-1, working with a NCOOH ratio of 5 and with a quantity of HDI of 500 g.

  The characteristics of the final product are: - NCO title: 8,15%; Viscosity at 25 ° C: 36,400 mPa s; - Translucent product.

  BI Application Tests The hardeners from Examples A-3 and A-4 were evaluated in a bi-component white paint formulation based on Synocure 866SD (dry extract = 75%). It is an acrylic polyol with a high solids content, recommended for reducing the Volatile Organic Compounds of coatings.

  EXAMPLE B-1 / Orientation Formula Based on Acrylic Polyol (Synocure 866SD) and HDT / IPDT Hardener Mix The orientation formula is given in the table below: Product Type Amount _ (g ) Part A Polyol 40.14 SYNOCURE 866SD DISPERBYK 161 / AMP (50-50 by weight) Dispersant 6.62 Tiona RCL 628 Titanium dioxide 66.2 Butyl acetate-solvess 100 Solvent 15.5 (60-40 by weight) SYNOCURE 866SD Polyol 60.08 DBTL (1% solution) Catalyst 2.29 Tinuvin 292 (0.1% solution) Anti UV 17.18 Tolonate HDT / sec hardener 50.18 Part B IPDT (70/30) dry / Solvent to reach 30s Ford 4,597 The hardener (Part B) is added to Part A, then the paints are diluted with a solvent to allow their application; the paints are sprayed on steel plates QD46; after 30 minutes of desolvation, the cooking is carried out for 30 minutes at 80 ° C. The characterization tests of the use values are carried out after having left the plates for 7 days at room temperature.

  In 2K PU formulation, HDT / IPDT blends are used to reduce the drying time, increase hardness recovery and therefore productivity; the IPDT rate used in the cutting is generally low, since the use of a large quantity of IPDT leads to a brittle coating; here, in the case of the paint described above, the use of 30% IPDT in the hardener shows the poor flexibility of the coating.

  Flexibility is measured by the impact test, which is to drop a weight of 1 kg of estimated height in cm (AFNOR) and a weight of one pound (Ibs) of an estimated height in inches. (see entire test method if necessary).

  Ref. Standard Hardener Hardener HDT HDT / XIDT 70/30 A 3 A 4 Shock at 7d ASTM 100 100 100 45/50 AFNOR 80 80 80 32 2867781 33 It is noted that the products resulting from examples A-3 and A-4 make it possible to obtain a flexibility equivalent to that of the HDT, and much better than that obtained during a cutting HDT / IPDT.

  In formula varnished with the same polyol, it is observed that it is possible to improve the properties obtained with the hardener A-4, namely the recovery of hardness through cutting with the XIDT, and to maintain a very good flexibility coating using, in particular, XIDT / A-4 (50/50) dry / dry cutting.

  Nature of A-4 HDT / XIDT A-4 / XIDT A-4 / XIDT products ratio 100% 70/30 80/20 50/50 Hardness 1 d 40 155 41 110

PERSOZ

  3j 40 315 126 250 7j 40 337 144 290 C1 Synthesis of urethane polyacrylates bearing isocvanate functional groups Example C-1 / Synthesis of an acrylic polyol in the presence of xanthate In a two-jacketed double-jacketed reactor equipped with anchor stirring and at reflux, the following monomers were charged: n-butyl acrylate: 1,920 g-styrene: 1,560 g-2 hydroxyethyl acrylate: 464 g-2 hydroxyethyl methacrylate: 520 g The mixture was heated to 30 ° C. and then 22.5 g was added. O-ethyl-S- (1-methoxycarbonylethyl) xanthate (CH3CHCO2CH3) S (C = S) OEt, polymerization control agent. The mixture is degassed with argon.

  The temperature of the reaction medium is then raised to 70 ° C. 5 g of azobisobutyronitrile (AIBN) are added to the reaction mixture. The polymerization is maintained for 5 hours at 70 ° C. The reaction medium is diluted to 85.6% of dry extract by addition of n-butyl acetate.

  The viscosity of the (co) polymer in solution is 32 900 mPas at 25 ° C. The OH content is about 3.04%. The average OH functionality is 8 per string.

  The average molecular weight of an (co) acrylic polymer chain is 4,465 g.

  Example C-2 / Synthesis of Acrylic Polyol in the Presence of Xanthate A solution A is prepared by mixing 500 g of butyl acrylate, 51.2 g of 2-hydroxyethyl acrylate and 384.1 g of xylene.

  In a 2 liter glass reactor equipped with a jacket and a stirring anchor, 15% by weight of the solution A is introduced with 11.48 g of O-ethyl-S- (1). methoxycarbonyl) ethyl) xanthate (CH3CHCO2CH3) S (C = S) OEt. 12 g of V-40 are added to the remaining fraction of solution A. The reactor is released with argon for 15 minutes, then the temperature is increased to 115 C. 1.34 g of 1,1'azobis (cyclohexane-1-carbonitrile) (V-40) are then added. At the same time, the continuous introduction of the remaining fraction of solution A is started. It is maintained for 6 hours. At the end of introduction, 1 of V-40 are added to the reaction medium. The reaction is continued for 1 hour. The temperature is then reduced to room temperature.

  A sample is taken and analyzed by size exclusion chromatography (C.E.S.). The number average molecular weight (Mn) is measured by eluting the (co) polymer in THF, with polystyrene calibration. Mn = 3200 g / mole.

  Analysis by gas chromatography shows that the residual monomers are less than 2% by weight compared with the monomers initially used during the polymerization.

  The OH functionality is 8 per string. The average molecular weight of the polymer chains before functionalization with HDI is of the order of 4,500 g. The OH title is equal to 1.3% relative to the polymer at 100% dry extract.

  Example C-3 / Synthesis of acrylic polyol in the presence of xanthate A solution A is prepared by mixing 450 g of butyl acrylate, 102.68 g of 2-hydroxyethyl acrylate and 384.1 g of xylene. In a glass reactor of 2 I equipped with a double jacket and a

  stirring anchor, are introduced 15% by weight of the solution A, with 11, 51 g of O-ethyl-S- (1-methoxycarbonyl) ethyl) xanthate (CH3CHCO2CH3) S (C = S) OEt. 12 g of V-40 are added to the remaining fraction of solution A. The reactor is released with argon for 15 minutes, then the temperature is increased to 115 C. 1.34 g of 1,1'- Azobis (cyclohexane-carbonitrile) (V-40) are then added. At the same time, the continuous introduction of the remaining fraction of solution A is started. It is maintained for 6 hours. At the end of introduction, 1 of V-40 are added to the reaction medium. The reaction is continued for 1 hour. The temperature is then reduced to room temperature.

  A sample is taken and analyzed by size exclusion chromatography (C.E.S.). The number average molecular weight (Mn) is measured by eluting the polymer in THF with polystyrene calibration. Mn = 3400 g / mole.

  Analysis by gas chromatography shows that the residual monomers are less than 2% by weight compared with the monomers initially used during the polymerization.

  The average OH functionality is 16 per string. The average molecular weight of the polymer chains before functionalization with HDI is of the order of 4,500 g.

  The OH title is 2.6% on 100% dry extract.

  EXAMPLE C-4 / Synthesis of an Isocyanate Functionalized Urethane Acrylic Polymer 225.2 g of hexamethylene diisocyanate (HDI) are charged to a double-jacketed three-neck reactor equipped with an anchor stirrer and a dropping funnel. About 34 moles, 56.3 grams of acrylic polymer of Example C-1 about 3% by weight. The NCO / OH ratio is of the order of 32. The NCO titre of the initial mixture is 0.950.

  The reaction mixture is brought to about 110 C. After 4 hours of reaction, the NCO titre of the reaction medium is 0.913, ie a degree of conversion to NCO of 3.9% in accordance with the level of hydroxyl functional groups carried by the polymer. The reaction is then stopped.

  The measured viscosity of the reaction mixture is about 100 mPas.

  The reaction mixture is then purified by distillation of the excess diisocyanate monomer HDI working at 140 ° C under partial vacuum (0.3mbar). 43.7 g of acrylic polymer with free isocyanate functions are recovered.

  EXAMPLE C-5 / Synthesis of an Isocyanate-functional Urethane Acrylic Polymer The procedure is as for Example A-4 using 1000 g of HDI and 200 g of a 61.3% solution of acrylic C-2 polymer. dry extract in n-butyl acetate and OH title equal to 1.3% relative to the polymer at 100% dry extract.

  The NCO / OH ratio is 39. The degree of conversion to NCO is 1.12% in good agreement with the hydroxyl function of the polymer.

  The reaction mixture is then purified by distillation of the excess diisocyanate monomer HDI working at 140 ° C under partial vacuum (0.3mbar).

  121.5 g of isocyanate functional acrylic polymer containing 100% solids is recovered.

  The NCO content is 0.114 moles of NCO per 100 g, ie 4.8% by weight.

  The viscosity of the polymer at 100% dry extract and at 25 ° C. is 39,850 mPas.

  EXAMPLE C-6 / Synthesis of an Isocyanate-functional Urethane Acrylic Polymer 1,570 g of HDI (ie 8.45 moles) and 150 g of a C-3 acrylic polymer solution (0.23 moles) are used. ) 60% dry extract and OH title equal to 2.6% relative to the polymer at 100% dry extract.

  The NCO / OH ratio is 37. The NCO titre of the reaction mixture is 1.022. After 5 hours of reaction, the reaction is stopped.

  The degree of conversion to NCO is in accordance with the expected hydroxyl function level of the polymer.

  The reaction mixture is then purified by distillation of the excess diisocyanate monomer HDI working at 140 ° C under partial vacuum (0.3mbar). 108 g of isocyanate functional acrylic polymer containing 100% solids is recovered.

  The NCO content is 0.162 moles of NCO per 100 g, ie 6.8% by weight.

  The viscosity of the polymer at 100% dry extract and at 25 ° C. is 94,900 mPas.

  D / Analysis of Polymers Obtained by Gel Permeation Chromatography Gel permeation chromatography is a common method of polymer analysis that controls the mass of polymers. This method was used to verify that the method of functionalization of the hydroxyl functions of the acrylic polymer by the selected diisocyanate monomers does not lead to a significant increase in mass, as a consequence of the bridging between the polymer chains between them.

  The acrylic polymers with NCO units and the starting polymer polyols were analyzed by gel permeation chromatography under the conditions defined below: separation at room temperature of the samples over a series of 5 mixed PLGEL markers E 30 cm, 3p - the injector is WATERS 717+ and the pump is Waters 515 - the detector is a refractometric detector RI ERMA - the eluent used is a mixture of dichloromethane / trifluoroacetic acid 2,5 per 1,000: and 0, 005 M of Bu4 BF4 - the flow rate is 1 ml / min the samples are solubilized in the solvent dichloromethane / trifluoroacetic acid (95/5) at a rate of 300 mg in 20 ml for the acrylic polymers with hydroxyl functions and 600 mg / 25 ml for functionalized polymers with NCO functions - the injected volume is 501 - the calibration of the molecular masses is made by comparison with a range of polystyrene of mass calibrated between 100 and 50,000 g / mole.

  Profile 1 obtained for Example C-5 shows that the functionalization of polyol C-2 was carried out without substantially bridging. The calculated average mass MW is 13,000 in polystyrene equivalent, it corresponds well to the mass of the polyol (MW 9000 in polystyrene equivalent) added to the 8 HDI patterns which confirms a very low amount of interchain bridging.

  Profile 1: Chromatograms of Polymers C-2 and C-5 Bo Bo 1 I l4o_Il EPSSS '\ R I. E! CM 114 1 R II Acrylic urethane polymer C-5 Polyol C-2Volume exclusion 2 IogM PST The profile 2 obtained for Example C-6 shows that the functionalization with HDI of polyol C-3 (from Mw 9,300 in polystyrene equivalent) has led to a little interchain bridging because it is observed that a two-mass curve with a third exclusion peak. The average calculated mass MW of 18,200 in polystyrene equivalents confirms that there has been some interchain bridging. However, the majority peak corresponds to the mass peak corresponding to the mass of the C-3 polyol plus the mass of the 16 HDI patterns.

  The amount of bypass is estimated at about 15%.

  Profile 2: Chromatograms of Polyols C-3 and Polyacrylate Urethane C-6 Polyacrylate Urethane C-6 Volume Exclusion Having some bridging comes from the high OH functionality of acrylic polymer C-3.

  Preparation of two-component polyurethane varnishes based on the acrylic polyol resins and polyacrylate urethane hardeners described in Examples C. The polyols used are described below: Polyols: * C-2, dry extract: 61.3%, 1.3% OH % on dry * TMP (Trimethylolpropane): 38% of OH on dry, dry extract: 97% CAS: 77-99-6 * HBPA (4,4'isopropylidenedicyclohexanol): 14% of OH on dry, dry extract: 95%, CAS: 80-04-6 * 2 ethyl 1-3 hexanediol: 23% OH, dry extract: 99%, CAS: 94-96-2, density: 0.93 Use of polyols :, We Trimethylol propane was diluted to 38% hot 50% OH in 2 ethyl-1,3-hexanediol (23% OH) or a dry OH level of 30.5%. The product is clear and viscous at room temperature.

  We diluted the HBPA at 14% of 15% OH at hot (120 C, HBPA melting point) in 2-ethyl-1,3 hexanediol (23% OH), ie a dry OH content of 21.65%. . The product is clear and viscous at room temperature.

  Hardeners: C-5: Dry extract: 100% Viscosity: 39850 mPas% NCO: 4.79% C-6-: Dry extract: 100% Viscosity: 94900 mPas NCO: 6.80% Application of the hardeners after dilution in the Butyl acetate: Final viscosity Concentration% NCO Density (mPa $) C-5 5295 90.2% 4, 32% 0.98 C-6 5232cp 87.4% 5.94% 0.98 NCO / OH = 1.05 Solvent: 60% solvesso100 / 40% butyl acetate Example E-1 / Results of tests with hardener C-5 Quantity in g C-2 / C-5 TMP / C-5 NCO / OH 1.05 1.05 Isocyanate : C-5 13.74 1.24 Polyol: C-2 or solubilized trimethylolpropane (TMP) 28.72 22.65 DBTL 1% in solvesso100 / butyl acetate 0.9 0.65 60% solvesso100 / 40% acetate butyl 7.54 15.45 (for Ford equivalent equivalent 4 to 25 ") Viscosity value to to mPa s 67.5 cp 79.0 cp Rhéovisco 2M torque: 69 torque: 81 Mobile D30 (torque in% and speed in t / ') speed: 75 speed: 75 Drying time without dust * + 5h + 5h Calculation VOC 386 379 An infrared analysis at the end of drying of the film p It can be concluded that the isocyanate functions involved in the varnish have fully reacted with the hydroxyl functions of the resin to form the expected polyurethane network.

  Example E-21 Results of Tests with C-6 Quantity in q C-2 / C-6 TMPIC6 HBPAIC-6 NCO / OH 1.05 1.05 1.05 Isocyanate: C-6 35.44 21.07 26.54 Polyol: C-2 or trimethylol propane 12.33 1.58 2.81 solubilized (TMP) or HBPA 0.975 0.6 0.78 DBTL 1% in solvesso 100 / butyl acetate 8.28 14. 68 16.65 60% solvessol00 / 40% butyl acetate (for a Ford equivalent equivalent 4 to 25 ") Viscosity value to in 74cp 82cp 73cp mPa.s torque 76 torque: 84 torque: 75 Rhéovisco 2M Mobile D30 (torque in% and speed in speed 75 speed: 75 speed: 75 t / ') in blue to be removed Drying time without dust * + 5H + 5H + 5H t2 + 5h Calculation VOC 220 423 400 An infrared analysis at the end of drying of the film makes it possible to conclude that the isocyanate functions involved in the varnish have totally reacted with the hydroxyl functions of the resin to form the expected polyurethane network. .

Claims (1)

41 CLAIMS   1. Process for obtaining (co) polymers bearing isocyanate functional groups, characterized in that a (co) polymer carrying functional hydrogen functional groups is subjected to the action of at least one isocyanate compound carrying at least two isocyanate functions, of which at least one is free.   2. Method according to claim 1, characterized in that the ratio between the isocyanate compound expressed in mol and the functions with mobile hydrogen expressed in equivalent is at least 1, advantageously 2, preferably 5, more preferably to 10.   3. Process according to claims 1 and 2, characterized in that the excess of isocyanate compound (s) is removed by distillation.   4. Process according to claims 1 to 3, characterized in that said (co) polymer carrying functional hydrogen functional groups is subjected to the action of a mixture of isocyanate compounds.   5. Process according to claims 1 to 4, characterized in that the mobile hydrogen functional group (s) carried by said (co) polymer are chosen from amine, amide, carboxylic, alcohol (including phenol), thiol or even active methylene.   6. Process according to claims 1 to 5, characterized in that said (co) polymer bearing functions with a mobile hydrogen is (co) polymer with controlled architecture, advantageously chosen from: - (co) block polymers of which at least one of the blocks carries 30 functions with mobile hydrogen; star (co) polymers; microgel (co) polymers; comb (co) polymers; hyper-branched (co) polymers.   7. Process according to claims 1 to 5, characterized in that said (co) polymer bearing functions with a mobile hydrogen is a star-type (co) polymer capable of being obtained by oligo- or polycondensation of polycondensable molecules, advantageously selected from lactones, lactams or cyclic ethers, on the functions of a polyfunctional molecule forming the core of the star and to grow arms therefrom from each function of said polyfunctional molecule, (especially tri-, tetra- or functional penta).   8. Process according to claims 1 to 7, characterized in that said (co) polymer carrying isocyanate functional groups has an isocyanate function content of at least 1, advantageously 2%, preferably 4% by weight.   9. Process according to claims 1 to 8, characterized in that said (co) polymer bearing isocyanate functional groups has an isocyanate function content of at most 20%, advantageously 15%, preferably 10% by weight.   10. Process according to Claims 1 to 9, characterized in that the said mobile hydrogen function (co) polymer has a mass Mn measured by gel permeation chromatography at most equal to 50 000, advantageously to 20 000, preferably 5,000.   11. (Co) polymer obtainable by the method according to one of claims 1 to 8, preferably of molecular weight Mn at most equal to 60 000, preferably 12 000.   12. (Co) polymer according to claim 11, characterized in that it comprises on the one hand at least one, advantageously at least two, preferably at least three, function (s) chosen (s) among thiocarbamate functions and thioallophanate; and on the other hand at least 5 functions chosen from those resulting from the reaction (s) of one, two or more isocyanate functional groups with a functional group chosen from mobile hydrogen functional groups other than thiol, in particular from the hydroxyl and amino functional groups.   13. Use of (co) polymers obtainable by the process according to claim 1 for preparing coating compositions.   14. Composition for coatings, characterized in that it comprises: a) at least one (co) polymer obtainable by the method of claims 1 to 10; b) at least one polyfunctional compound with a mobile hydrogen function, advantageously a polyol.   15. A composition according to claim 14, characterized in that it further comprises an oligomeric, preferably aliphatic isocyanate composition in an amount such that the isocyanate function content of the mixture A + C reaches a value of at least 5%, advantageously at 8%, preferably at 10%.   16. Composition according to claims 14 and 13, characterized in that it further comprises a condensation catalyst.   17. Composition according to claims 13 to 16, characterized in that it further comprises a pigment, including titanium dioxide.