Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/80—Masked polyisocyanates
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
  • C09D175/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
  • C08G18/72—Polyisocyanates or polyisothiocyanates
  • C08G18/80—Masked polyisocyanates
  • C08G18/8061—Masked polyisocyanates masked with compounds having only one group containing active hydrogen
  • C08G18/8096—Masked polyisocyanates masked with compounds having only one group containing active hydrogen with two or more compounds having only one group containing active hydrogen

Definitions

• the present invention relates to masked (poly) isocyanate compounds and their use in the manufacture of coatings.
• the present invention relates to (poly) isocyanates in which at least some of the isocyanate functional groups are masked, or protected, by at least two heat-labile protective radicals, radicals which are sometimes identified by the qualifier of "masking” or " blocking ".
• the subject of the present invention is in particular molecular compounds constituting a unit, whether it is of mono-, oligo- or polymeric nature, carrying isocyanate groups and capable of reacting with suitable co-reactants, such as alcohols, phenols, amines, aminophenols or amino-alcohols, advantageously at least partially bi- or polyfunctional, which can be of mono-, oligo- or poly-meric nature.
• suitable co-reactants such as alcohols, phenols, amines, aminophenols or amino-alcohols, advantageously at least partially bi- or polyfunctional, which can be of mono-, oligo- or poly-meric nature.
• the present invention also relates to a process for obtaining these new masked polyisocyanates.
• compositions for the preparation of polymers in particular polycondensates and reticulates resulting from the reaction of said protected polyisocyanates and of nucleophilic coreactants.
• This preparation is that which is used in industrial applications, such as coatings of all kinds and in particular those on textiles, on glasses, on papers, on metals and on building materials, and paints.
• masked isocyanate units are advantageous for several reasons. Firstly, they make it possible to propose, in a single packaging, compositions (including emulsions and suspensions) for obtaining a coating in which the isocyanate component is stable and not very sensitive to water. It follows that it is no longer necessary to use expensive anhydrous solvents specific for isocyanates and that it is possible to store for a long time, without degradation, the masked isocyanates under conditions where those which are free would degrade.
• masked polyisocyanates also makes it possible to reduce, or even eliminate, the possible toxic risk associated with the presence of free and unstable isocyanates.
• the improvement of this technique for masking isocyanate functional groups on reactive mono-, oligo- or polymeric units involves optimizing, generally lowering, the reaction temperature, that is to say that at which deprotection takes place, thus leading to the targeted polymerization and / or crosslinking.
• the unmasking temperature must be sufficiently high so that there is no risk of reaction during the storage period and this reaction temperature must be sufficiently low so that it is easy to carry out the polycondensation when this is desired.
• masking agents only real-time masking agents are considered to be those whose release temperature is between approximately 80 ° C. (two significant digits) and 200 ° C. (two significant digits), in other words, those which respond positively to the octanol test in the temperature range of 80 ° C to 200 ° C.
• one of the essential objectives of the present invention is to provide new polyisocyanates with masked functional groups and having a relatively low dissociation temperature for a limited time and with a dissociation yield compatible with polymerization techniques.
• a second objective of the invention is to provide polyisocyanates with masked functional groups which are soluble in the usual solvents used for this type of application.
• Another object of the invention is to provide new polyisocyanates with masked functional groups, which are only slightly or not toxic. that or at the very least very close to that of the group being released in the first place, that is to say the lowest temperature.
• the Applicant has described mixed masked isocyanates usable in powder paints, in which the isocyanate functions are masked by at least two masking agents, at least one of which has a non-carbon carboxylic function.
• the masking function of the group carrying the carboxylic group is inseparable from the catalytic function.
• the subject of the invention is therefore a composition of isocyanates at least partially masked, characterized in that it is masked by at least two different masking agents, chosen so that in the test with octanol at 110 ° C.
• the release percentages are measured at 110 ° C. according to the octanol test on the isocyanate completely masked by a single masking agent, the one for which the measurement is carried out.
• Masking agents can be divided into three groups: - those whose mobile hydrogen is carried by a chalcogen; 4
• Another object of the invention is to provide new polyisocyanates with masked functional groups, which are not hazardous and / or delicate to use and handle.
• Another objective of the invention is to provide new polyisocyanates with masked functional groups, which are economical.
• Another objective of the invention is to provide new polyisocyanates with masked functional groups, giving access to polymers (or rather polycondensates), possibly crosslinked, which satisfy the specifications of the applications.
• polyisocyanates comprising functional masking groups of the heterocycle (poly) nitrogen type, in particular triazole, respond particularly well to the first objective of the invention but very poorly to the second because of their low solubility in the usual solvents.
• the masking groups of the oxime type lead to masked polyisocyanates having good solubility in the usual solvents, but releasing the masking group at higher temperatures.
• some free oximes are known to be toxic.
• Phenols especially those whose aromatic nucleus is depleted in electrons such as hydroxypicolines and hydroxybenzoates (for example EP-A-680 984 and WO 98/4608).
• caprolactam caprolactam
• imides [-CO-] 2 NH
• cyclic such as succinimide
• unsaturated nitrogen heterocycles in particular with five links (advantageously doubly unsaturated), preferably comprising at least two heteroatoms (preferably nitrogen).
• diazoles such as glyoxalins and pyrazoles
• triazoles or even tetrazoles.
• the compounds of malonic nature that is to say an RCH ⁇ radical carrying two electron-withdrawing groups (such as carbonyl, nitrile, Rf or perfluoroalkyl).
• the following pairs of masking agents may be mentioned: methyl-amyl-ketoxime / 2-hydroxypyridine and dimethylpyrazole / 2-hydroxypyridine.
• the pyrazole / triazole pair has a ratio D of between 1.1 and 1.2.
• the invention particularly relates to an isocyanate composition at least partially masked, characterized in that it is masked by at least two different masking agents meeting the above condition, at least one of which reacts with the function isocyanate via an -OH group and at least one other reacts with the isocyanate function via an -NH group.
• the subject of the invention is also an isocyanate composition at least partially masked, characterized in that it is masked by two (or more) different masking agents meeting the above condition, reacting with the isocyanate function by through the group -NH.
• the invention also relates to an isocyanate composition at least partially masked, characterized in that it is masked by two different masking agents meeting the above condition, reacting with the isocyanate function via the -OH group.
• the two masking groups are present in a ratio (expressed in equivalents of masking function) of between 10/90 and 90/10, preferably 20/80 - 80/20.
• oximes are preferred. Mention may in particular be made of methyl ethyl ketoxime, acetone oxime, methylamyl ketoxime, the oxime of methyl pyruvate or the oxime of ethyl pyruvate (also designated by "POME").
• W and W identical or different, representing hydrocarbon, aliphatic, alicyclic, aromatic or heterocyclic groups, W and
• W can also represent together a carbon or heterocyclic ring. It is desirable that W and W are not simultaneously aromatic (that is to say that an aromatic cycle is directly linked to the carbon of the oxime function). W and W can also include any type of substituent.
• substituents examples include the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, alkaryl, heterocyclic, alkoxy perhaloalkyl (CF 3 , CCI 3 , etc.) and polyalkoxy groups.
• the substituents can in particular be electron-withdrawing substituents as described in patent application WO 97/24386.
• the alkyl, alkenyl, alkynyl and alkoxy groups generally contain from 1 (two for alkenyl and alkynyl) to ten carbon atoms, preferably from 1 (two for alkenyl and alkynyl) to six carbon atoms, the aryl groups being advantageously in C- 6 -C1 8 .
• ISO represents the remainder of the isocyanate molecule which may contain, as described above, other ioscyanate group (s).
• nitrogen heterocycles in particular polyazotés, preferably with five or six links, some examples of which consist of imidazole, pyrazole, triazoles (1,2,3- (triazole and 1,2,4-triazole), tetrazole and their derivatives substituted, triazoles being preferred, derivatives of these compounds bearing one or more substituents, that is to say at least one, two or three substituents, the substituents being as defined above for oxime.
• the preferred isocyanate compositions according to the invention are the compositions in which the masking groups are respectively an oxime and the triazole (1,2,3-triazole or 1,2,4-triazole), the oxime advantageously being methyl ethyl ketoxime, methyl amyl ketoxime, methyl pyruvate oxime or ethyl pyruvate oxime.
• the polyisocyanate composition comprises triazole / oxime masking groups, in particular for "true" oximes, that is to say the oximes carrying two C 1 alkyl chains carrying the group N- OH in the abovementioned report (at least 10% and up to 90% of triazole groups, more particularly when it included at least 50% of triazole groups), the release temperature of the masking groups was always lower than that of the oxime group and close to that of the triazole group.
• Triazole is a masking agent which is very difficult to use because the compounds which it gives are only soluble in very little solvent.
• An additional advantage of the present invention is to provide mixed masked compounds one of the masking agents of which is triazole (one mixed masked compounds in which one of the masking agents is triazole (one or the other isomer, in general a mixture of the two) and which have good solubility in the usual solvents while having the same advantages as triazole. Also, to obtain good solubility, when one of the masking agents is triazole, it is desirable that the latter is associated with at least one masking agent where the mobile hydrogen is carried by an oxygen, advantageously an oxime. A triazole / all masking agents mass ratio is advantageously at most equal to 2/3, preferably 50%. Solubility problems are found when two different compounds having 5-membered nitrogen heterocycles are used as masking agents, in which case, to avoid crystallinity and therefore insolubility in solvents, it is desirable:
• masking agents comprising 5-membered nitrogen heterocycles carrying substituents, the equivalent sum of the carbon atoms of the substituent groups reduced to the nitrogen rings (number of carbon atoms of the substituent groups / number of nitrogen rings to 5 links) being at least equal to 4, preferably 6.
• the amount of masking groups in addition to the two main ones does not exceed 30% in equivalents, advantageously not more than 25%, preferably not more than 20%, and in particular not more than 15% in equivalents relative to the sum of the masked functions of the polyisocyanate composition.
• the isocyanates for which the invention is most advantageous are those whose nitrogen atom is linked to a sp 3 hybridization carbon, and more particularly the aliphatic isocyanates. Mention may in particular be made of polymethylene diisocyanates (by for example, TMDI (TetraMethyleneDisisocyanate) and HDI
• IPDI isophorone diisocyanate
• NBDI norbornane diisocyanate
• IPDI isophorone diisocyanate
• NBDI norbornane diisocyanate
• the part of the skeleton connecting two isocyanate functions includes at least one polymethylene chain (CH2) ⁇ where ⁇ represents an integer from two to 10, advantageously from 4 to 8
• CH2 polymethylene chain
• the polyisocyanate composition comprises more than two masking groups, it is preferable, when one of the agents represents a 5-membered nitrogen heterocycle, that more than 30% equivalent of blocking agent (s) comprising a function are present reactive
• a masking agent comprising a secondary amine group carrying two aliphatic chains, such as for example diisopropylamine.
• Masking agents comprising a nitrogen heterocycle of aromatic or pseudoaromatic nature, such as pyrazole, triazole, imidazole, tetrazole, pyrazoline .. and generally having unsaturation in the cycle do not fall into this category.
• the percentage of residual free isocyanate function is preferably at most equal to 5%, advantageously 2%, preferably 1%.
• the release rate is quantified by the octanol test (see below).
• the masked polyisocyanate pure or in mixture, comes from a polyisocyanate, that is to say having at least two isocyanate functions, advantageously more than two (possibilities of fractional values since it is generally a mixture of more or less condensed oligomers), which itself most often results from a precondensation or a prepolymerization of unit diisocyanate (sometimes qualified in the present description as "monomer").
• 90% of the molecules constituting the mixture of these prepolymers or of these precondensates before masking have an average molecular mass at most equal to approximately 2000 (Mw), more commonly to approximately 1000 (Mw), the term approximately signifying that position zeros are not significant digits (in other words, only one digit is significant in this case).
• polyisocyanates used for the invention mention may be made of those of the biuret type and those of which the di- or trimerization reaction has led to four, five or six-membered rings.
• isocyanuric rings originating from a homo- or hetero-trimerization of various diisocyanates alone, with other isocyanate (s) [mono-, di--, or poly- isocyanate (s)] or with carbon dioxide (or carbon dioxide), in this case we replace a nitrogen from the isocyanuric cycle by an oxygen.
• Isocyanuric ring oligomers are preferred.
• the preferred polyisocyanates are those which have at least one aliphatic isocyanate function.
• at least one masked isocyanate function according to the invention is linked to the backbone via an sp3 type carbon advantageously carrying a hydrogen atom, preferably two. It is desirable that said sp3 type carbon is itself carried by a sp3 type carbon and advantageously provided with one, preferably two hydrogen atoms, to avoid that the isocyanate function considered is in the neopentyl position.
• composition according to the invention comprises a mixture of isocyanates
• said mixture has an average functionality (number of isocyanate functions, masked or not, per molecule containing it) greater than 2, advantageously at least equal to 2, 1 and at most equal to approximately 15, advantageously to 7, preferably equal to at least 2.4 and at most equal to 4.
• the present invention can also be transposed for latexes, and in particular latexes having masked isocyanate functions as described in the European patents of the Applicant EP-A-739 961 and EP-A-674 667.
• mixtures of isocyanate compounds in which at least one, advantageously at least two, preferably at least three of the following conditions are met: - at least one third, advantageously two thirds, preferably four fifths of the NCO functions free or masked are connected to a hydrocarbon skeleton, via a saturated carbon (sp3);
• At least one third, advantageously two thirds, preferably four fifths of said saturated carbons (sp3) carries at least one, advantageously two, hydrogen (s);
• saturated carbons (sp3) are at least for a third, advantageously at least for half, preferably at least for two-thirds, connected to said skeleton by a carbon atom itself carrying at least one hydrogen, advantageously of them.
• the masked polyisocyanates of the invention are obtained by reacting the polyisocyanates as defined above with the two types of masking compounds, in particular a masking compound comprising a reactive hydrogen provided by an OH function and a masking compound comprising a reactive hydrogen provided by an NH function, successively or simultaneously.
• One of the many advantages of the new polyisocyanates according to the invention is that they can serve as a basis for the preparation of polymers and / or cross-linkages and can be used in particular as one of the main constituents of coatings of all kinds, such as varnishes and paintings.
• the hardness qualities of the crosslinkable polymers are among those which are sought from a technical and functional point of view.
• the process for the preparation of polymers comprises the following stages:
• a co-reactant which contains derivatives having reactive hydrogens in the form of alcohol, phenol, thiol, certain amines including anilines; these derivatives can have aliphatic, alicyclic or aromatic hydrocarbon skeletons, preferably alkyls, including cycloalkylies and aralkyls, aryls, linear or branched, substituted or not (these co-reactants, in general polyols are in themselves known);
• the temperature is at most equal to around 300 ° C, preferably between 60 and 250 ° C and, more preferably still, between 100 and 200 ° C and this, for a duration less than or equal to 15 hours, preferably at 10 am, and more preferably still at 8 am.
• the preferred low-polar solvents are those which are well known to those skilled in the art and in particular aromatics such as benzene, ketones such as cyclohexanone, methyl ethyl ketone and acetone; light alkyl esters, in particular adipic esters; petroleum fractions of the type sold under the Solvesso® brand.
• the derivatives used in the composition of the coreactive agent are generally di-, oligo- or polyfunctional, can be monomeric or derived from di-, oligo- or polymerization and are used for the preparation of optionally crosslinked polyurethanes, their choice will be dictated by the functionalities expected for the polymer in the final application and by their reactivity.
• the invention therefore also relates to paint compositions comprising for successive or simultaneous addition:
• the invention also relates to the paints and varnishes obtained by the use of these compositions, with the possible release according to the above process.
• reaction is considered to be complete if it is carried out at more than 90%. In the context of the present invention, the test is carried out at 110 ° C.
• the reaction medium is then brought to the temperature tested.
• the release temperatures are lowered from the values indicated in a manner proportional to the amount of catalyst introduced.
• the choice of catalyst can also make it possible to play on the unmasking kinetics of one of the masking agents relative to the other and, consequently, on the crosslinking kinetics.
• the choice of catalyst will be guided by the constraints of the desired application.
• HDT true trimer of HDI
• MEKO methacrylate resin
• 1,2,4-triazole 1,2,4-triazole in 140.6 g of are introduced into a 500 ml jacketed reactor.
• AMP propylene glycol monoethyl ether acetate. A reaction exothermic takes place. At the end of this, the triazole is not completely dissolved.
• the title product is obtained having some traces of free NCO function, a potential NCO level of 10.7% and a viscosity of 72 poises (7200 mPa.s).
• Example 2 The procedure is as for Example 1 except that the following reagents are introduced into the reactor: HDT: 400 g
• 1,2,4-triazole 71.9 g MEKO: 92.1 g (excess 1.5%) A solid product is obtained which is crushed and stored in the freezer.
• HDT 250 g in Solvesso 100: 133.1 g.
• the temperature goes from 45 to 62 ° C. It is heated to 80 ° C. and maintained at this temperature for one hour.
• the title product is obtained having a potential NCO level of 10.43% and a viscosity of 22.1 poises (2210 mPa.s) at 25 ° C.
• Example 6 The procedure is as for Example 6 except that DMP (64 g) is introduced instead of MAKO and the amount of Solvesso 100 is 126.3 g.
• the title product is obtained with a potential NCO rate of
• DBTL decreases the release temperature by 10 ° C and 20 ° C respectively;
• the mixed MEKO / triazole blocking makes it possible to reduce the unlocking temperature by at least 10 ° C compared to MEKO alone, whatever the level of catalyst; - the mixed POME / Triazole blocking gives identical results to the POME blocking alone. This also represents an interest in terms of cost.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Polyurethanes Or Polyureas (AREA)
• Paints Or Removers (AREA)

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• 1998
  • 1998-07-29 FR FR9809718A patent/FR2781804B1/fr not_active Expired - Fee Related
• 1999
  • 1999-07-22 BR BR9912547-1A patent/BR9912547A/pt not_active Application Discontinuation
  • 1999-07-22 KR KR1020017001243A patent/KR20010071060A/ko not_active Application Discontinuation
  • 1999-07-22 CN CN99810676A patent/CN1317026A/zh active Pending
  • 1999-07-22 WO PCT/FR1999/001805 patent/WO2000006627A1/fr not_active Application Discontinuation
  • 1999-07-22 US US09/744,686 patent/US6965007B1/en not_active Expired - Lifetime
  • 1999-07-22 JP JP2000562422A patent/JP2002521541A/ja not_active Withdrawn
  • 1999-07-22 CA CA002338161A patent/CA2338161A1/fr not_active Abandoned
  • 1999-07-22 EP EP99932950A patent/EP1100840A1/fr not_active Withdrawn
  • 1999-07-22 AU AU49155/99A patent/AU756926B2/en not_active Ceased

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