Polyisocyanate compositions

Abstract

The invention relates to a new polyisocyanate composition for producing coatings, said composition comprising at least one monophenol alkyl compound, a mixture of phosphite compounds for preventing yellowing and/or precipitation of the composition, and optionally, a catalyst.

Claims

1. A polyisocyanate composition comprising: a) at least one polyisocyanate with the general formula (I): O═C═N—Y—(N═C═O)n wherein: Y is the remainder of an isocyanate or a polyisocyanate after elimination of an isocyanate function wherein Y is a group: linear or branched alkyl comprising 2 to 15 atoms of carbon, cycloalkyl comprising 3 to 15 atoms of carbon, linear or branched alkyl comprising 2 to 12 atoms of carbon, cycloalkyl comprising 3 to 12 atoms of carbon, linear or branched alkyl comprising 4 to 10 atoms of carbon, or cycloalkyl comprising 4 to 10 atoms of carbon; and n is at least equal to 1, b) a monophenol alkyl compound, wherein the monophenol alkyl compound comprises a hindered phenol or hindered thiophenol function, c) a mixture of phosphite compounds comprising a maximum of 17% of trialkyl phosphite moles in relation to the total phosphite moles, d) a cross-linking catalyst and e) additives.

2. The composition according to claim 1 wherein the trialkylphosphites are compounds according to the general formula (II): (R.sub.1O).sub.3P wherein each R.sub.1 independently represents an alkyl group of 1 to 20 atoms of carbon optionally substituted by a group containing a halogen or an aralkyl group of 5 to 20 atoms of carbon substituted by a group containing a halogen.

3. The composition according to claim 1 wherein the mixture of phosphite compounds comprises 15% maximum of trialkyl phosphite moles in relation to the total phosphite moles.

4. The composition according to claim 1 wherein the cross-linking catalyst comprises a tertiary amine, an amidine, an organo-metallic compound or a mixture thereof.

5. The composition according to claim 1 wherein the additives added are solvents, compounds with an anti-flocculant effect and/or humidity absorbers.

6. The composition according to claim 1 wherein the compounds are present in the following mass percentages: general formula (I) polyisocyanate between 97.9% and 99.98%, monophenol alkyl compound between 0.01% and 1% phosphite compound mixture 0.01% and 1% cross-linking catalyst between 0% and 0.1%.

7. The composition according to claim 1 wherein the compounds are present in the following mass percentages: general formula (I) polyisocyanate between 20% and 90%, monophenol alkyl compound between 0.01% and 1% phosphite compound mixture 0.01% and 1% cross-linking catalyst between 0% and 0.1% additives between 9.98% and 77.9%.

8. The composition preparation process according to claim 1 wherein the following compounds are mixed in any order: a) a polyisocyanate with the general formula (I): O═C═N—Y—(N═C═O)n wherein: Y is a group: linear or branched alkyl comprising 2 to 15 atoms of carbon, cycloalkyl comprising 3 to 15 atoms of carbon, linear or branched alkyl comprising 2 to 12 atoms of carbon, cycloalkyl comprising 3 to 12 atoms of carbon, linear or branched alkyl comprising 4 to 10 atoms of carbon, or cycloalkyl comprising 4 to 10 atoms of carbon; and n is at least equal to 1, b) a monophenol alkyl compound, c) a mixture of phosphite compounds comprising a maximum of 17% of trialkyl phosphite moles in relation to the total phosphite moles, d) a cross-linking catalyst and e) additives.

9. The composition preparation process according to claim 8 adapted to manufacture coatings, adhesives or paints.

10. A method for manufacturing coatings, adhesives or paints comprising the implementation of the composition according to claim 1.

Description

EXAMPLE 1: GENERAL EXAMPLE

(1) Different commercial products are used in order to produce the compositions described in the examples: Tolonate® HDT from Vencorex, with viscosity equal to 2400 mPa.Math.s at 25° C. and NCO titer equal to 22.5% Irganox 1135 ®: Benzenepropanoic acid, branched 3,5-bis (1,1-dimethyl-ethyl) 4-hydroxy-C7-C9 alkyl ester from BASF Doverphos 6 ® (Dov 6): triisodecyl phosphite from Dover Doverphos 7 ® (Dov 7): phenyldiisodecyl phosphite from Dover Doverphos 8 ® (Dov 8): diphenylisodecyl phosphite from Dover ADEKA 135A®: diphenylisodecyl phosphite from Adeka Palmerole

(2) The molar distribution of the phosphite, determined by phosphorous NMR, is presented in TABLE 1.

(3) TABLE-US-00001 TABLE 1 Tri- Diphenyl- Phenyl- Tri- isodecyl isodecyl diisodecyl phenyl phosphite phosphite phosphite phosphite ADK 135A ® 2.8 18 56.9 22.4 Dov 8 1.5 21.7 54.7 22 Dov 7 24.6 53.5 20.4 1.5 Dov 6 94.3 5.61 0.11 0

EXAMPLE 2: PRODUCTION OF POLYISOCYANATE COMPOSITIONS

(4) The compositions A to I are prepared as follows from the commercial products described in example 1:

(5) Different compounds are added to a 250 ml vial according to the polyisocyanate composition to be produced and the mixture is left one night in agitation on a pot roller at ambient temperature.

(6) The mass proportions of the different compounds present in the polyisocyanate compositions A to I are presented in TABLE 2.

(7) TABLE-US-00002 TABLE 2 Tolonate Irganox Dov 6 Dov 7 Dov 8 ADK 135 HDT ® (g) 1135 ® (g) (g) (g) (g) A ® (g) Composition A 100 / / / / / Composition B 100 0.34 / / 0.76 / Composition C 100 0.34 / / / 0.76  Composition D 100 0.34 0.038 / / 0.722 Composition E 100 0.34 0.076 / / 0.684 Composition F 100 0.34 0.114 / / 0.646 Composition G 100 0.34 0.152 / / 0.608 (comparative) Composition H 100 0.34 / 0.76 / / (comparative) Composition I 100 0.34 0.76  / / / (comparative)

EXAMPLE 3: COLORATION TEST

(8) In order to carry out the coloration tests, the same compositions as those in example 2 are produced in order to have different polyisocyanate compositions. From compositions A to I, compositions 1 to 9 are produced, adding and mixing different products in a 125 ml vial and leaving on a pot roller for one night to homogenize these new compositions produced.

(9) Once compositions 1 to 9 have been homogenized, the initial coloration value is measured using a Minolta CM-5 spectrophotometer. The coloration value is expressed in Hazen.

(10) In order to verify a coloration variability, compositions 1 to 9 are placed in the oven at 90° C. for 5 days then cooled down for one day and the coloration is measured again under the same conditions as the initial coloration measurement. We may then easily compare a coloration variation over time.

(11) The mass proportions of the different compounds present in compositions 1 to 9 are presented in TABLE 3.

(12) TABLE-US-00003 TABLE 3 Compositions 1 2 3 4 5 6 7 8 9 Butyl acetate 24.3 24.3 24.3 24.3 24.3 24.3 24.3 24.3 24.3 Solvesso 100 11.4 11.4 11.4 11.4 11.4 11.4 11.4 11.4 11.4 Methoxypropyl 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 acetate Xylene 8 8 8 8 8 8 8 8 8 Dibutyl tin 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 dilaurate (10% in butyl acetate) Composition A 53.3 / / / / / / / / Composition B / 53.3 / / / / / / / Composition C / / 53.3 / / / / / / Composition D / / / 53.3 / / / / / Composition E / / / / 53.3 / / / / Composition F / / / / / 53.3 / / / Composition G / / / / / / 53.3 / / Composition H / / / / / / / 53.3 / Composition I / / / / / / / / 53.3

(13) The initial coloration values (in Hazen) and the values after 5 days for compositions 1 to 9 are presented in TABLE 4.

(14) TABLE-US-00004 TABLE 4 Compositions 1 2 3 4 5 6 7 8 9 Initial 3 3 3 3 3 3 3 3 3 coloration Coloration 167 21 26 22 20 20 19 19 20 after 5 days

(15) The coloration of composition 1 which is the composition containing the Tolonate HDT® alone increases significantly after 5 days. On the contrary, the other compositions 2 to 9 which comprise both the irganox 1135 and at least one phosphite only show a slight change in coloration. In fact, a variation in coloration which exceeds 50 Hazen would be considered as true discoloration. We may therefore conclude that the nature of the phosphite used has no influence on the Hazen coloration value after 5 days.

EXAMPLE 4: PRECIPITATION TEST

(16) In order to verify whether the different compositions precipitate, compositions A to I are produced as in example 3 then are placed in the oven at 50° C. for 7 days. Compositions 10 to 18 are then produced from compositions A to I in the oven, mixing different products in a 125 ml vial and leaving on a pot roller for one night to homogenize these new compositions produced. Compositions 10 to 18 are then transferred to turbidity measurement tubes for HACH ratio turbidimeter.

(17) The mass proportions of the different compounds present in compositions 10 to 18 are presented in TABLE 5. Compositions 16 to 18 are comparative compositions.

(18) TABLE-US-00005 TABLE 5 Compositions 10 11 12 13 14 15 16 17 18 Butyl acetate 38.1 24.3 24.3 24.3 24.3 24.3 24.3 24.3 24.3 Solvesso 100 ® 18.5 11.4 11.4 11.4 11.4 11.4 11.4 11.4 11.4 Glycol butyl 11.4 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 acetate Composition A 32 / / / / / / / / Composition B / 32 / / / / / / / Composition C / / 32 / / / / / / Composition D / / / 32 / / / / / Composition E / / / / 32 / / / / Composition F / / / / / 32 / / / Composition G / / / / / / 32 / / (comparative) Composition H / / / / / / / 32 / (comparative) Composition I / / / / / / / / 32 (comparative)

(19) In order to be able to carry out turbidity measurements at regular intervals, the initial turbidity is measured then the measurement tubes for compositions 10 to 18 are put back into the oven at 50° C. and the turbidity (expressed in NTU) is read after 1, 4 and 7 days. The results of the turbidity measurements in compositions 10 to 18 are presented in TABLE 6.

(20) TABLE-US-00006 TABLE 6 Composition 10 11 12 13 14 15 16 17 18 Initial 0.17 0.2 0.23 0.25 0.25 0.28 0.32 0.17 0.32 turbidity (NTU) Turbidity 0.17 0.2 0.28 0.32 0.32 0.35 0.40 0.44 2.5 after 1 day at 50° C. (NTU) Turbidity 0.18 0.19 0.3 0.43 0.38 0.42 6.8 60 >200 after 4 days at 50° C. (NTU) Turbidity 0.19 0.26 0.31 1.04 0.88 0.73 12.5 >200 >200 after 7 days at 50° C. (NTU)

(21) The limit for detection with the naked eye of turbidity in a composition is set at 1 NTU. As shown in TABLE 6, the turbidity of compositions 10 to 15 never exceeds 1 NTU. There are no deposits visible to the eye for compositions 10 to 15 and we can therefore consider that compositions 10 to 15 are stable. However, compositions 16 and 18 exceed the limit of 1 NTU after 4 days or even a single day in the case of composition 18. Compositions 16, 17 and 18 quickly present turbidity and are therefore absolutely not stable.

(22) TABLE 7 summarizes the results of the coloration test in example 3, the precipitation test in example 4 and the trialkyl phosphite/total phosphite molar ratio for compositions A to I which were used to prepare compositions 1 to 14. For the yellowing test, beyond 50 Hazen measured at a maximum 5 days at 90° C., the coloration of the composition is considered as too high and therefore the test fails (fail). Below this value, the test is successful (pass). For the precipitation test, beyond the limit set of 1 NTU at maximum 7 days at 50° C., the precipitation of the composition is considered as too visible and the test fails (fail), in the contrary case the test is validated (pass).

(23) TABLE-US-00007 TABLE 7 Yellowing Precipitation test by test by Trialkyl phosphite/total Compositions composition composition phosphite molar ratio A 1: fail 10: pass / B 2: pass 11: pass 1.5 C 3: pass 12: pass 2.8 D 4: pass 13: pass 6.5 E 5: pass 14: pass 10.3 F 6: pass 15: pass 14.2 G (comparative) 7: pass 16: fail 18.2 H (comparative) 8: pass 17: fail 24.6 I (comparative) 9: pass 18: fail 94.3

(24) Compositions B to F validate both tests simultaneously, which is not the case for compositions A, G, H and I. These compositions B to F are characterized by a trialkyl phosphite/total phosphite molar ratio lower than 15%.