NOVEL COMPOSITIONS WITH IMPROVED CHARACTERISTICS

Abstract

The present invention relates to novel compositions comprising cyanate ester resins and substituted bisimides (citraconimides, bisitaconimide, citraconimido-itaconimide, bisnadicimide, bistetrahydroimide and mixtures thereof) as defined in claim 1, and thermoset composite materials based on these compositions.

Claims

1. A composition comprising components (a) and (b) wherein component (a) is one or more cyanate esters independently selected from (i) a difunctional cyanate ester compound of formula (I) ##STR00116## wherein R.sup.1 through R.sup.8 are independently selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl, halogenated linear C.sub.1-10 alkyl, branched C.sub.4-10 alkyl, halogenated branched C.sub.4-10 alkyl, C.sub.3-8 cycloalkyl, halogenated C.sub.3-8 cycloalkyl, C.sub.1-10 alkoxy, halogen, phenyl and phenoxy; Z.sup.1 indicates a direct bond or a divalent moiety selected from the group consisting of —O—, —S—, —S(═O)—, —S(═O).sub.2—, —CH.sub.2—, —CH(CH.sub.3)—, —C(CH.sub.3).sub.2—, —CH(CF.sub.3)—, —C(CF.sub.3).sub.2—, —C(═O)—, —C(═CH.sub.2)—, —C(═CCl.sub.2)—, —Si(CH.sub.3).sub.2—, linear C.sub.1-10 alkanediyl, branched C.sub.4-10 alkanediyl, C.sub.3-8 cycloalkanediyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, —N(R.sup.13)— wherein R.sup.13 is selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl, halogenated linear C.sub.1-10 alkyl, branched C.sub.4-10 alkyl, halogenated branched C.sub.4-10 alkyl, C.sub.3-8 cycloalkyl, phenyl and phenoxy, and moieties of formulas ##STR00117## wherein X is independently selected from hydrogen and halogen; and oligomers, prepolymers, polymers or mixtures thereof; and/or (ii) a polyfunctional cyanate ester of formula (II) ##STR00118## wherein n is an integer from 1 to 20; and R.sup.10 and R.sup.11 are identical or different and independently from each other selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl and branched C.sub.4-10 alkyl; and oligomers, prepolymers, polymers or mixtures thereof, and mixtures of cyanate esters of formula (I) and (II); and wherein component (b) is one or more substituted bisimide compound independently selected from a compound of formula (X) ##STR00119## wherein * and ** each denotes a covalent bond to the respective C atom denoted with * and ** of a residue, wherein the residues are identical or different and independently selected from ##STR00120## and wherein R is independently selected from alkyl, cycloalkyl, alkyne, aryl, aralkyl and alkaryl; and, oligomers, prepolymers, polymers or mixtures of these compounds.

2. A composition according to claim 1 wherein component (a) is one or more cyanate esters independently selected from (i) a difunctional cyanate ester compound of formula (I) ##STR00121## wherein R.sup.1 through R.sup.8 are independently selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl, C.sub.3-8 cycloalkyl; Z.sup.1 indicates a direct bond or a divalent moiety selected from the group consisting of —O—, —S—, —S(═O)—, —S(═O).sub.2—, —CH.sub.2—, —CH(CH.sub.3)—, —C(CH.sub.3).sub.2—, —CH(CF.sub.3)—, —C(CF.sub.3).sub.2—, —C(═O)—, —C(═CH.sub.2)—, —C(═CCl.sub.2)—, —Si(CH.sub.3).sub.2—, linear C.sub.1-10 alkanediyl, branched C.sub.4-10 alkanediyl, C.sub.3-8 cycloalkanediyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, —N(R.sup.13)— wherein R.sup.13 is selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl, C.sub.3-8 cycloalkyl, phenyl and phenoxy, and moieties of formulas ##STR00122## wherein X is independently selected from hydrogen and halogen; and oligomers, prepolymers, polymers or mixtures thereof; and/or (ii) a polyfunctional cyanate ester of formula (II) ##STR00123## wherein n is an integer from 1 to 20; and R.sup.10 and R.sup.11 are identical or different and independently from each other selected from the group consisting of hydrogen, linear C.sub.1-10 alkyl and branched C.sub.4-10 alkyl; and oligomers, prepolymers, polymers or mixtures thereof; and mixtures of cyanate esters of formula (I) and (II).

3. A composition according to claim 1 wherein component (b) is one or more substituted bisimide compound independently selected from a compound of formula (X) ##STR00124## wherein * and ** each denotes a covalent bond to the respective C atom denoted with * and ** of a residue, wherein the residues are identical or different and independently selected from ##STR00125## and wherein R is independently selected from aryl, linear or branched C.sub.1-10 alkyl, C.sub.3-C.sub.8 cycloalkyl, C.sub.2-10 alkyne or the moiety <<“N”-R-“N”>>, wherein <<“N”-R-“N”>> is an aromatic amine moiety independently selected from (“N” denotes the point of connectivity) ##STR00126## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from hydrogen, C.sub.2-C.sub.20 alkyl, C.sub.2-C.sub.20 alkene, C.sub.2-C.sub.20 alkyne, halogen, NO.sub.2, and sulfone, wherein the halogen is selected from Cl, Br, F, or I; X is independently selected from C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkene, C.sub.2-C.sub.20 alkyne and sulfone; and oligomers, prepolymers, polymers or mixtures thereof.

4. A composition according to claim 1 wherein component (a) is one or more cyanate esters independently selected from (i) a difunctional cyanate ester compound of formula (I) ##STR00127## wherein R.sup.1 through R.sup.8 are independently selected from the group consisting of hydrogen, linear C.sub.1_.sub.3 alkyl; Z.sup.1 indicates a direct bond or a divalent moiety selected from the group consisting of —O—, —S—, —S(═O).sub.2—, —CH.sub.2—, —CH(CH.sub.3)—, —C(CH.sub.3).sub.2—, —C(CF.sub.3).sub.2—, —C(═CCl.sub.2)—, branched C.sub.4-6 alkanediyl, C.sub.3-8 cycloalkanediyl, 1,2-phenylene, 1,3-phenylene, 1,4-phenylene; and oligomers, prepolymers, polymers or mixtures thereof; and/or (ii) a polyfunctional cyanate ester of formula (II) ##STR00128## wherein n is an integer from 1 to 10; and R.sup.10 and R.sup.11 are identical or different and independently from each other selected from the group consisting of hydrogen, linear C.sub.1-5 alkyl and branched C.sub.4-6 alkyl; and oligomers, prepolymers, polymers or mixtures thereof, and mixtures of cyanate esters of formula (I) and (II).

5. A composition according to claim 1 wherein component (b) is one or more substituted bisimide independently selected from a biscitraconimide compound of formula (X1), ##STR00129## wherein R is selected from o-xylylene, and oligomers, prepolymers, polymers or mixtures thereof, or b1) at least one selected from the group of biscitraconimide compound of formula (X1), bisitaconimide compound of formula (X2) and citraconimido-itaconimide compound of formula (X3), ##STR00130## or b2) a bisnadicimide compound of formula (X4) and oligomers, prepolymers, polymers or mixtures thereof, ##STR00131## or b3) a bistetrahydroimide compound of formula (X5) and oligomers, prepolymers, polymers or mixtures thereof ##STR00132## wherein R is independently selected from aryl, linear or branched C.sub.1-C.sub.10 alkyl, C.sub.3-C.sub.8 cycloalkyl, C.sub.2-C.sub.10 alkyne or the moiety <<“N”-R-“N”>>, wherein <<“N”-R-“N”>> is an aromatic amine moiety independently selected from (“N” denotes the point of connectivity) ##STR00133## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from hydrogen, C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkene, C.sub.2-C.sub.20 alkyne, halogen p, NO.sub.2, and sulfone, wherein the halogen is selected from Cl, Br, F, or I; X is independently selected from C.sub.1-C.sub.20 alkyl, C.sub.2-C.sub.20 alkene, C.sub.2-C.sub.20 alkyne and sulfone; and oligomers, prepolymers, polymers or mixtures thereof.

6. A composition according to claim 1 wherein component (a) is one or more cyanate esters independently selected from (i) a difunctional cyanate ester compound of formula (I) ##STR00134## wherein the difunctional cyanate ester of formula I is independently selected from the group consisting of i) R.sup.1, R.sup.2, R.sup.5 and R.sup.6 are methyl, R.sup.3, R.sup.4, R.sup.7 and R.sup.8 are hydrogen and wherein Z.sup.1 is —CH.sub.2-(methylene) and oligomers, prepolymers, polymers or mixtures thereof, or ii) R.sup.1 through R.sup.8 are hydrogen and Z.sup.1 is —C(CH.sub.3).sub.2— and oligomers, prepolymers, polymers or mixtures thereof, or iii) R.sup.1 through R.sup.8 are hydrogen and Z.sup.1 is —S— and oligomers, prepolymers, polymers or mixtures thereof, or iv) R.sup.1 through R.sup.8 are hydrogen and Z.sup.1 is —C(CF.sub.3).sub.2— and oligomers, prepolymers, polymers or mixtures thereof, or v) R.sup.1 through R.sup.8 are hydrogen and Z.sup.1 is —C(═CCl.sub.2)— and oligomers, prepolymers, polymers or mixtures thereof, or vi) R.sup.1 through R.sup.8 are hydrogen and Z is independently selected from the group consisting of ##STR00135##  (Primaset® LM-500) and oligomers, prepolymers, polymers or mixtures thereof, or vii) R.sup.1 through R.sup.8 are hydrogen and Z is ##STR00136##  (Primaset® DT-4000) and oligomers, prepolymers, polymers or mixtures thereof, or viii) R.sup.1 through R.sup.8 are hydrogen and Z is —CH(CH.sub.3)— and oligomers, prepolymers, polymers or mixtures thereof, and oligomers, prepolymers, polymers or mixtures thereof, and/or (ii) a polyfunctional cyanate ester of formula (II) ##STR00137## wherein the polyfunctional cyanate ester is independently selected from the group consisting of compound III, compound IV, compound V, compound VI, and oligomers, prepolymers, polymers or mixtures thereof.

7. A composition according to a claim 1 wherein component (b) is one or more substituted bisimide independently selected from a biscitraconimide compound of formula (X1), ##STR00138## wherein R is selected from o-xylylene, and oligomers, prepolymers, polymers or mixtures thereof, or b1) at least one selected from the group of biscitraconimide compound of formula (X1), bisitaconimide compound of formula (X2) and citraconimido-itaconimide compound of formula (X3), ##STR00139## or b2) a bisnadicimide compound of formula (X4) and oligomers, prepolymers, polymers or mixtures thereof, ##STR00140## or b3) a bistetrahydroimide compound of formula (X5) and oligomers, prepolymers, polymers or mixtures thereof ##STR00141## wherein R is the moiety <<“N”-R-“N”>> which is an aromatic amine moiety independently selected from (“N” denotes the point of connectivity) ##STR00142## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently selected from hydrogen, C.sub.1-C.sub.5 alkyl, halogen, NO.sub.2, and sulfone, wherein the halogen is selected from Cl, Br, F, or I; and oligomers, prepolymers, polymers or mixtures thereof.

8. A composition according to claim 1 wherein the ratio of component (a) to (b) is 80 wt % component (a) to 20 wt % component (b) based on total amount of the resin composition.

9. A composition according to claim 1 wherein the composition further comprises a catalyst selected from the group consisting of aliphatic mono-, di- and polyamines, aromatic mono-, di- and polyamines, carbocyclic mono-, di and polyamines, heterocyclic mono-, di- and polyamines, compounds containing a five- or six-membered nitrogen-containing heterocyclic ring, hydroxyamines, phosphines, phenols, and mixtures thereof.

10. A composition according to claim 1 wherein the composition further comprises reinforcement fibres selected from the group consisting of carbon fibres, glass fibres (such as E glass fibres, S glass fibres), aramid fibres (including KEVLAR®), basalt fibres (geotextile fibers), natural fibres (such as flax, hemp, jute or sisal), fleeces and woven fabrics (multi-layered or single layered), and mixtures thereof.

11. A composition according to a claim 1 wherein the composition further comprise a filler selected from the group consisting of organic fillers, such as thermoplastics and elastomers, inorganic fillers, such as glass microspheres, graphite or silica, and mineral powder fillers, such as CaCO.sub.3, coated CaCO.sub.3, kaolin clay, SiO.sub.2, talc, graphite, corundum (α-Al.sub.2O.sub.3), wollastonite, SiC, glass microspheres, mica, calcium silicate (Ca.sub.2O.sub.4Si), MgO, anhydrous calcium sulfate (CaSO.sub.4 or anhydrite), ceramic hollow microspheres, fused mullite (Al.sub.2O.sub.3—SiO.sub.2), boron nitride (BN), vermiculite, or basalt, and mixtures thereof.

12. A composition according to claim 1 wherein component (a) is one or more cyanate esters independently selected from (i) a difunctional cyanate ester compound of formula (I) ##STR00143## wherein R.sup.1 through R.sup.8 are hydrogen and Z.sup.1 is —CH(CH.sub.3)— and oligomers, prepolymers, polymers or mixtures thereof; and/or (ii) a polyfunctional cyanate ester of formula (II) ##STR00144## wherein the polyfunctional cyanate ester is independently selected from the group consisting of compound III, compound IV, compound V, and oligomers, prepolymers, polymers or mixtures thereof, ##STR00145## and mixtures of cyanate esters of formula (I) and (II); and wherein component (b) is a biscitraconimide compound of formula (X1), ##STR00146## wherein R is selected from o-xylylene, and oligomers, prepolymers, polymers or mixtures thereof.

13. A method for the preparation of a composition according to claim 1 comprising the steps of: i) providing a mixture components according to a claim 1; and ii) intimately mixing the components together.

14. A method for the preparation of a thermoset composite material comprising the steps of: i) providing a mixture components according to claim 1; ii) intimately mixing the components together; iii) casting the mixture into the desired form; and iv) initiating polymerization of the mixture.

15. A method for producing a thermoset composite material comprising a composition as defined in claim 1.

Description

EXAMPLES

[0444] Abbreviations

TABLE-US-00001 TMA Thermal mechanical analysis MSDS Material Safety Data Sheet RT Room temperature Tg Glass transition temperature

TABLE-US-00002 BMI-5100 Bismaleimide from Dawei Kasei JP, CAS NO: 105391-33-1, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethane bismaleimide BMI-2300 Phenylmethane maleimide from Dawei Kasei JP, CAS NO: 67784-74-1 Perkalink ® 900 1,3-bis(citraconimidomethyl)benzene, from Lanxess Homide 400 1,3-Bis((3-methyl-2,5-dioxopyrrol-1-yl)methyl)benzol, homide 400 oligomer: 1,3-Bis((3-methyl-2,5-dioxopyrrol-1- yl)methyl)benzol, polymer, or mixtures of homide 400 monomer and homide 400 oligomer from HOS Technik Cyanate ester IV compound of formula IV of Lonza Ltd, Switzerland, CAS NO: 87397- 54-4, also the following CAS-number are applicable: CAS 153191-90-3, CAS 173452-35-2 Cyanate ester Primaset ® LeCy of Lonza Ltd, Switzerland, CAS NO: 47073-92-7 LeCy

Experimental Procedure for Examples 1 and 2

[0445] A cyanate ester was heated at 85-90° C. in order to decrease its viscosity and was casted into two aluminum pans with diameter of 5 cm containing each 6 g of the cyanate ester. The cyanate ester was cured and post-cured using the following cure cycle:

[0446] Cure cycle: heat-up from 25° C. to 150° C. at 1K/min, hold 1 h at 150° C. [0447] heat-up from 150° C. to 200° C. at 1K/min, hold 3 h at 200° C. [0448] heat-up from 200° C. to 260° C. at 1K/min, hold 1 h at 260° C.

[0449] The cured cyanate ester is cooled to RT and was removed from the aluminum pan (de-molded). The cured material was evaluated in term of mass loss (thermal-oxidative stability) and glass transition temperature.

[0450] The cured material had the following dimensions: diameter=5 cm, thickness=2 cm

[0451] The components and their amounts in gram (g) and wt % (% based on the total weight of the mixture) are given in table 1 (g) and table 2 (wt %).

Experimental Procedure for Examples 3, 5 and 6

[0452] A substituted bisimide was liquefied at 130-140° C. and casted into two aluminum pans with diameter of 5 cm containing each 6 g of substituted bisimide. The bisimide was placed inside a vacuum oven at 120-125° C. and degassed at less than 100 mbar vacuum pressure for 10-15 min to remove any air present in the bisimide. The substituted bisimide was cured and post-cured using the following cure cycle:

[0453] Cure cycle: heat-up from 25° C. to 175° C. at 1K/min, hold 3 h at 175° C. [0454] heat-up from 175° C. to 220° C. at 1K/min, hold 2 h at 220° C. [0455] heat-up from 220° C. to 260° C. at 1K/min, hold 16 h at 260° C.

[0456] The cured substituted bisimide is cooled to RT and was removed from the aluminum pan (de-molded). The cured material was evaluated in term of mass loss (thermal-oxidative stability) and glass transition temperature.

[0457] The cured material had the following dimensions: diameter=5 cm, thickness=2 cm The components and their amounts in gram (g) and wt % (% based on the total weight of the mixture) are given in table 1 (g) and table 2 (wt %).

Experimental Procedure for Examples 7, 8, 9 and 10

[0458] A cyanate ester and a substituted bisimide are mixed at 130-135° C. till complete homogenization and poured into two aluminum pans with diameter of 5 cm containing each 6 g of said mixtures. The mixture was then placed inside a vacuum oven at 120-125° C. and degassed at less than 100 mbar vacuum pressure for 10-15 min to remove any air bubbles present in the mixture. The mixture was then cured and post-cured using the following cure cycle:

[0459] Cure cycle: heat-up from 25° C. to 175° C. at 1K/min, hold 3 h at 175° C. [0460] heat-up from 175° C. to 220° C. at 1K/min, hold 2 h at 220° C. [0461] heat-up from 220° C. to 260° C. at 1K/min, hold 16 h at 260° C.

[0462] The cured “cyanate ester—bisimide mixture” is cooled to RT and was removed from the aluminum pan (de-molded). The cured material was evaluated in term of mass loss (thermal-oxidative stability) and glass transition temperature.

[0463] The cured material had the following dimensions: diameter=5 cm, thickness=2 cm

[0464] The components and their amounts in gram (g) and wt % (% based on the total weight of the mixture) are given in table 1 (g) and table 2 (wt %).

TABLE-US-00003 TABLE 1 the components and their amounts in gram (g) for example 1 to 10 Example 1 2 3 5 6 7 8 9 10 Cyanate ester III 15 10 14 8 12 Primaset ® LeCy 15 4 4 Homide 400 15 10 6 8 4 BMI-2300 15 BMI-5100 15 Total gram 15 15 15 15 15 20 20 20 20

TABLE-US-00004 TABLE 2 the components and their amounts in wt % based on the total weight of the mixture for example 1 to 10 Example 1 2 3 5 6 7 8 9 10 Cyanate ester III 100 50 70 40 60 Primaset ® LeCy 100 20 20 Homide 400 100 50 30 40 20 BMI-2300 100 BMI-5100 100 Example 1 2 3 5 6 7 8 9 10 Total wt % 100 100 100 100 100 100 100 100 100

Experimental Procedure for Testing of Cured Materials for Examples 1 to 10

[0465] The thermal oxidative stability of above cured samples is evaluated based upon weight loss during isothermal aging at 250° C. and the material surface damage detected visually. The cured sample (diameter 5 cm and thickness of 2 cm) was placed in an oven at 250° C. for a long term aging test. The initial weight (w.sub.0) of the cured sample was measured with an analytical balance resolution of at least 0.1 mg before starting aging test. Then the sample weight was re-measured (w.sub.xhours) after different thermal aging periods at 250° C. The correspondent mass loss in % was calculated using the following formula:

Mass Loss [%]=((w.sub.0−w.sub.xhours)/w.sub.0)×100

[0466] The sample was then re-placed in the oven at 250° C. for aging test. The result are given in table 3. The cured samples were further examined visually to detect any damage, results are given in table 4.

[0467] Samples of the cured composition were cut to specimens and the glass transition temperature (Tg) was analysed by Thermal Mechanical Analysis (TMA) and the results are given in table 3.

[0468] Glass transition temperature is the temperature, at which the physical properties of a polymeric materials change from amorphous rigid, glassy or crystalline state to a flexible rubbery state. The machine used was a Mettler Toledo instrument TMA SDTA840. The sample dimensions were 6×6 mm2 (length×width) and 2.0 mm thickness. The test method applied two heating ramps (1.sup.st heat-up: 25-250° C. at 10 K/min, 2.sup.nd heat-up: 25-400° C. at 10 K/min). The Tg was evaluated on the second ramp. The result are given in Table 3.

TABLE-US-00005 TABLE 3 Mass loss and Tg onset for examples 1 to 10 mass loss mass loss mass loss T.sub.g onset 500 h at 1000 h 3000 h by TMA Example 250° C. [%] at 250° C. [%] at 250° C. [%] [° C.]  1 1.28 2.31 6.99 ~350  2 **NR 3.85 31.19 250-260  3 0.98 1.48 2.66 235-245  5 5.2 18.81 **NR >300  6 19.52 35.86 **NR >300 *7 **NR 1.66 3.89 260-270 *8 **NR 1.97 5.16 275-285 *9 **NR 1.60 5.70 255-265 *10  **NR 2.14 8.46 270-280 **NR = not recorded

TABLE-US-00006 TABLE 4 Material damage detection by visual examination after 1000 hours aging at 250° C. for examples 1 to 10 Example Visual appearance after 1000 hours aging at 250° C.  1 Scattered microcracking formation  2 Remarkable material shrinkage/deformation  3 No cracking occurred  5 Surface decomposition, crumbled and void formation  6 Material sintered *7 No cracking occurred, surface smooth *8 No cracking occurred, surface smooth *9 No cracking occurred, surface smooth *10  Scattered microcracking formation