FR2770532A1 - Catalyst, used in isocyanate trimerisation - Google Patents

Abstract

Hydrogen carbonate of a cation is used as catalyst for cyclotrimerisation of isocyanates. The complexed have ionic radius greater than 1 Angstrom and are at least partially soluble in the reaction medium. Hydrogen carbonate of a cation is used as catalyst for cyclotrimerisation of isocyanates. The ions are in the form of a complex with a complexing agent, and have ionic radius greater than 1 Angstrom , preferably greater than 1.5 Angstrom . The ions are at least partially soluble in the reaction medium. An Independent claim is also included for a polyisocyanate composition obtained using the catalyst.

Description

 The subject of the invention is a catalyst which is useful for the catalytic cyclotrimerization of monomeric isocyanates to (poly) isocyanurate polyisocyanates.

 It is known to prepare isocyanate trimers by catalytic trimerization of an isocyanate using a catalyst based on a quaternary ammonium hydroxide.

 Thus, EP-003 765 describes the partial cyclotrimerization of isophorone diisocyanate (1PDl or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane) by using a hydroxide of a quaternary hydroxyalkylammonium as catalyst.

 In general, catalysts based on a quaternary ammonium hydroxide have a very high reactivity which makes it difficult to control the trimerization reaction, in particular when the starting isocyanate is an aliphatic or cycloaliphatic isocyanate.

 In addition, the control of the reaction is made even more difficult by the possible variations of the hydrolysable chlorine content of the starting isocyanate, from the phosgenation process used for the synthesis of these isocyanates.

 It is known that the effectiveness of the catalyst decreases when the hydrolyzable chlorine content contained in the IPDI increases.

 The hydrolysable chlorine content also influences the coloration of the crude reaction product which increases as the amount of chlorine is high.

No. 4,040,992 also describes catalytic trimerization catalysts for isocyanates of the quaternary ammonium salt type, the anion of which is represented by OH-, or the formula ~ OOC ~ (O) a ~ Y in which Y is chosen from:
a hydrogen atom,
an alkyl group having 1 to 20 carbon atoms,
an alkenyl group having 2 to 15 carbon atoms
a cycloalkyl group having from 3 to 6 carbon atoms,
a phenyl group,
an alkylphenyl group having from 1 to 9 carbon atoms in the alkyl radical or in the groups bonded to the phenyl nucleus,
a benzyl group,
a carbamate group,
an alkylbenzyl group having 1 to 9 carbon atoms in the alkyl radical or in the benzyl ring-bonded groups, and
a group CH (> bZ (b) wherein b is an integer of 1 to 3 and Z is OH, CN, Cl, an alkoxy group of 1 to 5 carbon atoms, or a phenyl or methoxyphenyl group, or
Z is (CH2) dCOOR wherein d is an integer of 0 to 4 and
R is a hydrogen atom or an alkyl group having up to 20 carbon atoms;
and a is zero or 1.

 However, the anions exemplified in this patent are all alkylcarboxylic acid derived anions. In general, the catalysts described in this document do not make it possible to achieve the desired goal.

 The object of the invention is to provide a catalyst for the cyclotrimerization of isocyanates, especially diisocyanates which allows a control of the reaction, while having an acceptable conversion rate, which is not substantially dependent on the chlorine content. hydrolysable, the starting isocyanate and provides a product whose color is not marked significantly.

 It has now surprisingly been found that the ionic type catalysts whose counteranion is the hydrogen carbonate ion would achieve the desired purpose.

 These catalysts are formed of a monatomic or polyatomic cation bulky, either as such, or in the form of a complex formed with a complexing agent, in particular of the cryptant type.

The invention thus relates to the use as a cyclotrimerization reaction catalyst of isocyanates of a hydrogen carbonate of a cation which, either as such, or in complexed form with a complexing agent, has an ionic radius or average molecular weight greater than 1 A, preferably greater than 1.5, as defined in the tables of M. Shannon and
Prewitt in Acta Cris, 1969, vol. B25, page 925 and which is at least partially soluble in the reaction medium.

 Advantageously, the cation is chosen from bulky alkali metal cations, in particular rubidium and cesium.

 The cation may also consist of a light alkali metal cation, in complexed form. Mention may in particular be made of sodium and potassium cations complexed with crown ethers.

 The cation may also consist of a molecular species, in which all atoms are linked by covalent bonds.

 In this respect, mention may be made of "onium" type cations of which the representative species are phosphoniums, sulfoniums and quaternary ammoniums.

dans laquelle
Q représente un atome d'azote, de phosphore ou de soufre; et
R1, R2, R3 et R4 identiques ou différents désignent des groupes alkyle, éventuellement hydroxylés, ayant 1 à 20 atomes de carbone, des restes cycloalkyle ayant de 4 à 15 atomes de carbone, éventuellement substitués avec des groupes hydroxyle, des restes aralkyle ayant 7 à 15 atomes de carbone, éventuellement substitués avec des groupes hydroxyle ou des restes aryle ayant 6 à 15 atomes de carbone, éventuellement substitués avec des groupes hydroxyle ou bien lorsque Q est N, deux des restes R1, R2, R3 ou R4 peuvent aussi former avec l'atome d'azote et, le cas échéant, avec un hétéro atome notamment d'oxygène ou d'azote, un noyau hétérocyclique ayant 4 à 6 atomes de carbone, ou bien lorsque Q est N, les restes R1, R2 et R3 représentent chacun des restes éthylène qui forment en association avec l'atome quaternaire d'azote et un autre atome tertiaire d'azote, un squelette de triéthylènediamine bicyclique, ou l'un de R1 à R4 représente un groupe

dans lequel R5, R6 et R7 identiques ou différents représentent l'hydrogène, un groupe OH, un groupe alkyle ayant 1 à 12 atomes de carbone, un groupe cycloalkyle ayant 5 à 7 atomes de carbone, un groupe alkényle ayant de 2 à 15 atomes de carbone, un groupe alkynyle ayant de 3 à 6 atomes de carbone, un groupe hydroxyalkyle ayant de 1 à 9 atomes de carbone, un groupe aralkyle ayant de 7 à 10 atomes de carbone, un groupe aryle ayant de 6 à 10 atomes de carbone ou un groupe R8-0-(CH2)n dans lequel R8 est l'hydrogène, un reste alkyle ayant de 1 à 12 atomes de carbone, un reste cycloalkyle ayant de 4 à 10 atomes de carbone, un reste aralkyle ayant de 7 à 10 atomes de carbone ou un reste aryle ayant de 6 à 10 atomes de carbone ; et n est un nombre entier allant de 1 à 6 ; R7 pouvant en outre également représenter un groupe OCORg, R9 étant un groupe alkyle en C1-C6, de préférence en Ci-Ca, plus particulièrement le groupe méthyle.Particularly preferred are the hydrogencarbonates of the following Formula I cations:

in which
Q represents a nitrogen, phosphorus or sulfur atom; and
R1, R2, R3 and R4, which may be identical or different, denote alkyl groups, optionally hydroxylated, having 1 to 20 carbon atoms, cycloalkyl residues having from 4 to 15 carbon atoms, optionally substituted with hydroxyl groups, aralkyl radicals having 7 to 15 carbon atoms, optionally substituted with hydroxyl groups or aryl radicals having 6 to 15 carbon atoms, optionally substituted with hydroxyl groups or when Q is N, two of the radicals R1, R2, R3 or R4 may also form with the nitrogen atom and, where appropriate, with a hetero atom, in particular oxygen or nitrogen, a heterocyclic ring having 4 to 6 carbon atoms, or when Q is N, the radicals R1, R2 and R3 are each ethylene moieties which together with the nitrogen quaternary atom and another tertiary nitrogen atom form a bicyclic triethylenediamine backbone, or one of R1 to R4 represents a group of

wherein R5, R6 and R7, which are identical or different, are hydrogen, an OH group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an alkenyl group having 2 to 15 atoms of carbon, an alkynyl group having 3 to 6 carbon atoms, a hydroxyalkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or an R8-O- (CH2) n group in which R8 is hydrogen, an alkyl residue having 1 to 12 carbon atoms, a cycloalkyl residue having 4 to 10 carbon atoms, an aralkyl residue having 7 to 10 carbon atoms or an aryl residue having 6 to 10 carbon atoms; and n is an integer from 1 to 6; R7 may furthermore represent a group OCORg, R9 being a C1-C6 alkyl group, preferably C1-Ca, more particularly the methyl group.

The cation is more particularly represented by the following general formula II:

R1, R2 and R3 represent identical or different radicals and denote alkyl groups, optionally hydroxylated, having 1 to 20 carbon atoms, cycloalkyl radicals having from 4 to 15 carbon atoms, optionally substituted with hydroxyl groups, aralkyl radicals; having 7 to 15 carbon atoms, optionally substituted with hydroxyl groups or aryl radicals having 6 to 15 carbon atoms, optionally substituted with hydroxyl groups, two of the radicals R1, R2 or R3 which may also form with the atom nitrogen, and optionally, with a hetero atom of oxygen or another hetero atom of nitrogen, a heterocyclic ring having 4 to 6 carbon atoms, or the radicals R 1, R 2 and R 3 each representing ethylene radicals which form in combination with the quaternary nitrogen atom and another tertiary nitrogen atom, a bicyclic triethylenediamine backbone,
R5, R6 and R7, which are identical or different, represent hydrogen, an OH group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an alkenyl group having 2 to 15 carbon atoms , an alkynyl group having 3 to 6 carbon atoms, a hydroxyalkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a RsO (CH2) n group wherein R8 is hydrogen, an alkyl residue having 1 to 12 carbon atoms, a cycloalkyl residue having 4 to 10 carbon atoms, an aralkyl residue having 7 to 10 carbon atoms or an aryl residue having from 6 to 10 carbon atoms; and n is an integer from 1 to 6; R7 may furthermore also represent a group OC OR9, R9 being a C1-C6, preferably C1-C4, alkyl group, more particularly the methyl group.

A preferred quaternary ammonium cation group consists of compounds wherein:
R 1, R 2 and R 3, which may be identical or different, represent a linear C 1 -C 4 alkyl group, preferably C 1 -C 3 alkyl, more particularly C 1 -C 2 alkyl, and preferably methyl,
- R5 represents H, OH, the methyl group or the hydroxymethyl group,
- R6 represents H, OH, the methyl group or the hydroxymethyl group,
R7 represents H, OH, methyl group, hydroxymethyl group or acetyl group,
Another group of preferred quaternary ammonium cations are the compounds in which:
R 1, R 2 and R 3, which are identical or different, represent a C 1 -C 4 alkyl group, preferably a C 1 -C 3 alkyl group, more particularly a C 1 -C 3 alkyl group;
C1-C2, and preferably methyl,
R5 represents H or a C1-C4 alkyl group,
R6 represents H, OH or a C1-C4 alkyl group;
R7 represents H, OH, a C1-C4 alkyl group or the acetyl group.
without the total of the carbon atoms of R1 to R7 exceeding 8, preferably 6.

 More preferably, the quaternary ammonium cations in which at least one, preferably two, and more preferably the three groups of R1 to R3 are methyl are preferred, R5, R6 and R7 being as defined above. , and preferably only one of R5 to R7 being OH.

 Another group of preferred quaternary ammonium cations is that in which R 1 to R 3 represent a C 1 -C 4 alkyl group, a C 1 -C 4 hydroxyalkyl group, and R 5 to R 7 represent H or OH, said compounds advantageously comprising a single group OH in position omega relative to the central nitrogen atom.

 A more particularly preferred catalyst is choline hydrogencarbonate, especially when the isocyanate which is to be cyclotrimerized is a cycloaliphatic diisocyanate, such as NBDI, IPDI or H12MDI, or a mixture of a cycloaliphatic diisocyanate such as mentioned above and a linear or branched chain aliphatic diisocyanate, especially HDI.

 There may also be mentioned tetramethylphosphonium hydrogen carbonate or sulfonium and tetraphenylphosphonium hydrogen carbonate or sulfonium.

 The catalysts according to the invention are known compounds.

dans laquelle R1 à R3 sont tels que définis ci-dessus avec un époxyde de formule générale lil:

They can be obtained especially in the case of quaternary ammoniums, when R7 represents OH by reaction of a tertiary amine of general formula II:

wherein R1 to R3 are as defined above with an epoxide of the general formula

 wherein R4 and R5 are as defined above, in the presence of CO2 and H2O.

 In the case of esters, the hydroxylated quaternary ammonium may be esterified using an acylimidazole, for example. In the case of ethers, we will work with an excess of epoxy.

 The process according to the invention can be used for the cyclotrimerization of any type of isocyanate, or a mixture of isocyanates whether aliphatic, cycloaliphatic or aromatic, including prepolymers having terminal isocyanate groups, in particular those described in US 5,115,071. whose contents are incorporated by reference in this application. It can thus be used for the trimerization of isocyanates in the presence of various diols, triols and other polyols whose molecular weights are in a wide range, including polyols and aminopolyols comprising polyether and polyester groups, used for the production of polyurethane resins and polyisocyanurates.

 It is advantageously used for the cyclotrimerization of IPDI (isophorone diisocyanate or 1-isocyanato-3,3,5-trimethyl-5-isocyanato methyl cyclohexane), NBDI (norbornane diisocyanate or 2,5 (6) -diisocyanatomethyl- bicyclo [2,2,1] heptane) and H12MD1 (4,4'-dicyclohexylmethanediyl diisocyanate), alone or in admixture with other diisocyanates, especially with a linear aliphatic chain, such as HUI (hexamethylene diisocyanate) ).

 Advantageously, the catalyst according to the invention is added in an amount of between 300 and 5000 ppm, preferably between 500 and 3500 ppm relative to the total amount of starting isocyanates.

 The catalyst is added to the reaction medium with stirring, preferably in the absence of a solvent. The reaction is allowed to proceed for a time varying between 1 h and 4 h, preferably about one hour and a half.

 The reaction is advantageously carried out at a temperature of between room temperature and 1200.degree. C., preferably between 40 and 100.degree. C., advantageously under a neutral atmosphere.

 The invention also relates to the use of the catalyst in a solid form such as for example obtained by depositing the catalyst on a mineral such as silica, or by covalent attachment to a resin.

 The subject of the invention is also a process for the catalytic trimerization of isocyanates, in particular diisocyanates or isocyanate mixtures, especially diisocyanates, characterized in that ammonium hydrogencarbonate is used as trimerization catalyst. quaternary as defined above.

The subject of the invention is also a polyisocyanate (poly) isocyanurate composition obtained by the process according to the invention, in particular comprising the following compounds:
- the trimer of the NBDI,
the trimer of H12MDI,
- the trime of the IPDI,
the mixed trimers NBDI, IPDltHDI or H12MDI / HDI, in which the proportion of HDI can vary from 5 to 95% by weight.

 The products obtained may subsequently undergo a chemical reaction: dimerization, allophanation, biuretization, blocking reaction with a blocking agent (or masking) either before or after distillation of the monomer.

 The compounds obtained are used for the preparation of coatings, especially as basic constituents for varnishes and paints.

 The following examples illustrate the invention.

 EXAMPLE 1 Preparation of isophorone diisocyanate tri mother (IPDT).

 11.800 g of IPDI are charged to a reactor. It is stirred under a stream of argon and heated to 85 ° C.

 When the temperature is stabilized, 0.56 g (0.07% by weight) of choline bicarbonate is charged. The reaction is allowed to continue for 3 hours, following the evolution of the IPDI conversion rate by measuring the NCO titre (by potentiometry).

 80 g of the IPDT corresponding to a conversion rate of 10% are obtained.

 EXAMPLE 2 Preparation of trimer isophorone diisocyanate (IPDT)

 The procedure is as for Example 1 except that 1.6 g (0.2% by weight) of choline bicarbonate is added and the reaction is heated to 60 ° C.

 320 g of lPDT corresponding to an IPDI transformation rate of 40% are obtained.

EXAMPLES 3 to 5: Comparative Examples
The reactivity of choline hydrogencarbonate with that of choline hydroxide, choline bisulfite and choline bitartrate was compared.

The results of Examples 1 to 5 are reported in the table below.

<Tb>

Examples <SEP> Catalyst <SEP> [cata] <SEP> * <SEP> Temperature <SEP> of <SEP> reaction <SEP> TT <SEP> IPDI
<tb><SEP>%<SEP> in <SEP> weight <SEP> (C) <SEP> (%)
<tb><SEP> choline <SEP> bicarbonate <SEP> 0.07 <SEP> 85 <SEP> 10
<tb><SEP> 2 <SEP> Choline <SEP> Bicarbonate <SEP>: <SEP> 0.2 <SEP> 60 <SEP> 40
<tb><SEP> 3 <SEP> choline <SEP> hydroxide <SEP> - <SEP> 0.07 <SEP> 85 <SEP> 40
<tb><SEP> 4 <SEP> choline <SEP> bisulfite <SEP> 0.07 <SEP> 85 <SEP> 0
<tb><SEP> 5 <SEP> choline <SEP> bitartrate <SEP> 0.2 <SEP> 80 <SEP> 0
<tb> * [cata] are calculated from 100% choline salts.

 It appears that different salts of choline, only bicarbonate has a lower catalytic activity and more easily controllable, namely 2.8 times less activity than that of choline hydroxide.

Claims (14)

 1. Use as an isocyanate cyclotrimerization reaction catalyst of a hydrogen carbonate of a cation which, either as such or in complexed form with a complexing agent, has an average ionic or molecular radius greater than 1 A preferably at 1.5 A, and which is at least partially soluble in the reaction medium.  2. Use according to claim 1, characterized in that the cation corresponds to the general formula 1:

 in which Q represents a nitrogen, phosphorus or sulfur atom; and R1, R2, R3 and Ra, which are identical or different, are optionally hydroxylated alkyl groups having 1 to 20 carbon atoms, cycloalkyl residues containing from 4 to 15 carbon atoms, optionally substituted with hydroxyl groups, aralkyl radicals having 7 to 15 carbon atoms, optionally substituted with hydroxyl groups or aryl radicals having 6 to 15 carbon atoms, optionally substituted with hydroxyl groups or when Q is N, two of the radicals R1, R2, R3 or R4 may also form with the nitrogen atom and, if appropriate, with a heteroatom especially of oxygen or nitrogen, a heterocyclic ring having 4 to 6 carbon atoms, or when Q is N, the radicals R1, R2 and R3 represent each of the ethylene residues that form in association with The quaternary nitrogen atom and another tertiary nitrogen atom, a bicyclic triethylenediamine backbone, or one of R1 to Ra represents a group

 in which Rs, R6 and R7, which are identical or different, represent hydrogen, an OH group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an alkenyl group having 2 to 15 atoms of carbon, an alkynyl group having 3 to 6 carbon atoms, a hydroxyalkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or an R8-O- (CH2) n group in which R8 is hydrogen, an alkyl residue having 1 to 12 carbon atoms, a cycloalkyl residue having 4 to 10 carbon atoms, an aralkyl residue having 7 to 10 carbon atoms or an aryl residue having 6 to 10 carbon atoms; and n is an integer from 1 to 6; R 7 may furthermore also represent a CORS group, R 8 being a C 1 -C 6 alkyl group, preferably a C 1 -C 4 alkyl group, more particularly a methyl group.  3. Use according to claim 2, characterized in that the cation corresponds to the following general formula II:

  in which R1, R2 and R3 represent identical or different radicals and denote alkyl groups, optionally hydroxylated, having t to 20 carbon atoms, cycloalkyl radicals having from 4 to 15 carbon atoms, optionally substituted with hydroxyl groups, aralkyl radicals having 7 to 15 carbon atoms, optionally substituted with hydroxyl groups or aryl radicals having 6 to 15 carbon atoms, optionally substituted with hydroxyl groups, two of the radicals R 1, R 2 or R 3 also being able to form with the nitrogen atom and, where appropriate, with a hetero atom of oxygen or another hetero atom of nitrogen, a heterocyclic ring having 4 to 6 carbon atoms, or the radicals R 1, R 2 and R 3 each represent ethylene radicals which form in combination with the quaternary nitrogen atom and another tertiary nitrogen atom, a bicyclic triethylenediamine backbone, Rs, R6 and R7, which are identical or different, represent hydrogen, an OH group, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an alkenyl group having 2 to 15 carbon atoms , an alkynyl group having 3 to 6 carbon atoms, a hydroxyalkyl group having 1 to 9 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms or a Rs-O- (CH 2) group, wherein R 8 is hydrogen, an alkyl residue having 1 to 12 carbon atoms, a cycloalkyl residue having 4 to 10 carbon atoms, an aralkyl residue having 7 to 10 carbon atoms. 10 carbon atoms or an aryl residue having 6 to 10 carbon atoms; and n is an integer from 1 to 6; R7 can also represent a group OCORg, R9 being a C1-C61 alkyl group preferably C1-C4, more particularly the methyl group.  4. Use according to claim 1, characterized in that:  R1, R2 and R3, which may be identical or different, represent a linear C1-C4 alkyl group, preferably a C1-C31 alkyl group, more particularly a C1-C2 alkyl group, and preferably a methyl group;  - R5 represents H, OH, the methyl group or the hydroxymethyl group,  - R6 represents H, OH, the methyl group or the hydroxymethyl group,  - R7 represents H, OH, the methyl group, the hydroxymethyl group or the acetyl group.  5. Use according to claim 1, characterized in that:  R1, R2 and R3, which may be identical or different, represent a C1-C41 alkyl group, preferably a C1-C31 alkyl group, more particularly a lower alkyl group; C1-C2, and preferably methyl,  R5 represents H or a C1-C4 alkyl group,  R6 represents H, OH or a C1-C4 alkyl group;  R7 represents H, OH, a C1-C4 alkyl group or the group  acetyl, without the total of the carbon atoms of R, R7 exceeding 8, preferably 6.  6. Use according to claim 1, characterized in that at least one, preferably two and more preferably the three groups of R1 to R3 represent the methyl group, R5, R6 and R7 being as defined above, and preferably only one of R5 to R7 being OH.  7. Use according to claim 1, characterized in that R1 to R3 represent a C1-C4 alkyl group, a C1-C4 hydroxyalkyl group and R5 to R7 represent H or OH, said compounds advantageously comprising a single OH group in position omega with respect to the central nitrogen atom.  8. Use according to claim 1, characterized in that the compound is choline hydrogen carbonate.  9. Use according to any one of the preceding claims, characterized in that the amount of catalyst is from 300 ppm to 5000 ppm, preferably from 100 ppm to 3500 ppm, relative to the isocyanate monomer or to the mixture of isocyanates monomers .  10. Use according to claim 1, characterized in that the catalyst is in solid form obtained by depositing the hydrogencarbonate on a solid or covalent attachment to a support.  11. Use according to any one of the preceding claims, for the preparation of the trimer of isophorone diisocyanate or a mixed trimer diisophorone diisocyanate and hexamethylene diisocyanate wherein the proportion of hexamethylene diisocyanate varies from 5 to 95% in weight.  12. Use according to any one of claims 1 to 11, for the preparation of the norbornane diisocyanate trimer or a mixed trimer of norbornane diisocyanate and hexamethylene diisocyanate wherein the proportion of hexamethylene diisocyanate varies from 5 to 95 % in weight.  13. Use according to any one of claims 1 to 11, for the preparation of 4,4'dicyclohexylmethane diisocyanate tri-mother or a mixed triad of 4,4'dicyclohexylmethanediyl diisocyanate and hexamethylene diisocyanate in which the proportion of hexamethylene diisocyanate varies from 5 to 95% by weight.  14. Composition of polyisocyanates (poly) isocyanurates obtained by cyclotrimerization of isocyanates alone or mixed with a catalyst as defined in claims 1 to 13.