Patent Description:
Composite materials comprising organic matrices are widely used for a variety of purposes. The chemical composition of the organic matrix may be selected depending on the desired properties of the composite material.

Cyanate esters are molecules in which the hydrogen atom of a phenolic OH group has been substituted with a cyanide (C=N) group. Cyanate esters can be cured by heating, for example alone at elevated temperatures or at lower temperatures in the presence of a catalyst. The resulting cured resinous materials have relatively high glass-transition temperatures and low dielectric constants, thus providing good long-term thermal stability at elevated temperatures, good toughness, and good fire, smoke and toxicity performance. Blends of two or more cyanate esters, or blends of one or more cyanate ester(s) with one or more other components, can be formulated to fine-tune one or more properties of the material before and/or after curing. Such properties may include, for example, the processability/fluidity/viscosity prior to curing, thermo-mechanical properties (e.g. glass-transition temperature), thermal and thermo-oxidative stability, reactivity, flame retardancy, and moisture absorption.

United States patent <CIT> discloses a resin composition that comprises: a bifunctional phenylene ether oligomer that has a polyphenylene ether skeleton (a), an aralkyl-based cyanate ester compound (b), a bisphenol-based cyanate ester compound (c), an epoxy resin (d), a brominated carbonate oligomer (e), an inorganic filler (f), and a thioether-based polymerization inhibitor (h) selected from: tetrakis-methylene-<NUM>-(laurylthio)propionate methane, β-laurylthiopropionate, tetrakismethylene-<NUM>-(laurylthio)propionate methane, pentaerythrityl-tetrakis(<NUM>-laurylthiopropionate) and pentaerythrityl-tetrakis(<NUM>-dodecylthiopropionate). The resin composition has favourable electrical characteristics and heat resistance after moisture absorption that is suitable for producing printed-wiring boards.

It is however desirable to provide new resin blends, particularly new resin blends comprising one or more cyanate esters.

The present invention provides a composition, a cured resinous material, a composite material, and an article, as set out in the appended claims.

According to a first aspect, there is provided a composition comprising:.

According to a second aspect, there is provided a cured resinous material obtained by or obtainable by curing a composition of the first aspect.

According to a third aspect, there is provided a composite material comprising a cured resinous material of the second aspect.

According to a fourth aspect, there is provided an article comprising a cured resinous material of the second aspect or a composite material of the third aspect.

There is disclosed herein a ternary resin blend (i.e. a composition comprising at least three different components) which can be cured in order to form a resinous material which can be used as a matrix in composite materials.

The compositions disclosed herein comprise:.

R<NUM> and R<NUM> are the same or different and are selected from hydrogen and halogen. R<NUM> and R<NUM> are the same or different and may be halogen.

R<NUM> and/or R<NUM> may, for example, be halogen. R<NUM> and R<NUM> may, for example, be the same. R<NUM> and R<NUM> may, for example, be the same halogen.

Where one or both of R<NUM> and R<NUM> are halogen, the halogen may be selected from fluorine, chlorine, and bromine. For example, where one or both of R<NUM> and R<NUM> are halogen, the halogen may be selected from chlorine and bromine. For example, where one or both of R<NUM> and R<NUM> are halogen, the halogen may be chlorine. For example, R<NUM> and R<NUM> may be chlorine.

R<NUM>, R<NUM>, R<NUM> and R<NUM> are hydrogen.

R<NUM> and R<NUM> may, for example, be halogen and R<NUM>, R<NUM>, R<NUM> and R<NUM> asre hydrogen. For example, R<NUM> and R<NUM> may be selected from fluorine, chlorine, and bromine, and R<NUM>, R<NUM>, R<NUM> and R<NUM> are hydrogen. For example, R<NUM> and R<NUM> may be selected from chlorine and bromine, and R<NUM>, R<NUM>, R<NUM> and R<NUM> are hydrogen.

The compound of formula (I) may, for example, be bisphenol C (BPC) having the structure below:
<CHM>.

As used herein, the term "cyanate ester" refers to a molecule in which the hydrogen atom of a phenolic OH group has been substituted with a cyanide (-C≡N) group. A "polyfunctional cyanate ester" is a cyanate ester which comprises more than one cyanide groups.

The polyfunctional cyanate ester may have a glass-transition temperature equal to or greater than about <NUM>, when cured. For example, the polyfunctional cyanate ester may have a glass-transition temperature equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, when cured. For example, the polyfunctional cyanate ester may have a glass-transition temperature equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, when cured. For example, the polyfunctional cyanate ester may have a glass-transition temperature ranging from about <NUM> to about <NUM> or from about <NUM> to about <NUM> or from about <NUM> to about <NUM> or from about <NUM> to about <NUM>, when cured. This refers to the glass-transition temperature of the polyfunctional cyanate ester when cured alone (i.e. without the other components in the ternary resin blend).

Glass-transition temperature may, for example, be measured by Dynamic Mechanical Analysis (DMA), for example according to ASTM D4065-<NUM> or D5279-<NUM>.

The polyfunctional cyanate ester is a novolac cyanate ester.

Novolacs are polymers derived from phenol derivatives and formaldehyde such that the phenolic units are linked by methylene and/or ethylene groups in the ortho and/or para positions. The phenol derivative may, for example, be phenol or methylphenol. The ratio of formaldehyde to phenol derivative may, for example, be less than one. The novolac may, for example, comprise from about <NUM> to about <NUM> phenolic units.

Novolac cyanate esters are novolacs in which one or more hydrogen atom(s) of one or more phenolic OH group(s) are substituted with a cyanide (-C≡N) group. For example, the novolac cyanate ester may be a novalac in which the hydrogen atoms of two or more phenolic OH groups have been substituted with cyanide (-C≡N) groups. For example, the novolac cyanate ester may be a novolac in which all of the hydrogen atoms of the phenolic OH groups have been substituted with cyanide (-C≡N) groups.

The polyfunctional cyanate ester may, for example, be an oligomer of formula (II) below:
<CHM>
wherein n is <NUM>, <NUM> or <NUM>.

The polyfunctional cyanate ester of formula (II) may, for example, have a molecular weight ranging from about <NUM>/mol to about <NUM>/mol, for example from about <NUM>/mol to about <NUM>/mol, for example from about <NUM> to about <NUM>/mol.

The polyfunctional cyanate ester may, for example, be the material referred to as Primaset® PT-<NUM> supplied by Lonza Group Ltd or the material referred to as AroCy® XU-<NUM> novalac-based cyanate ester supplied by Huntsman Advanced Materials.

As used herein, the term "cyanate ester" refers to a molecule in which the hydrogen atom of a phenolic OH group has been substituted with a cyanide (-C≡N) group.

As used herein, the term "bisphenol" refers to molecules with two hydroxyphenyl groups. The bisphenol may, for example, be diphenylmethane with one hydroxyl group on each phenyl ring.

A "bisphenol-derived cyanate ester" is a bisphenol in which the hydrogen atom of each hydroxyl group on the phenyl rings has been substituted with a cyanide (-C≡N) group. An "asymmetric bisphenol-derived cyanate ester" is a bisphenol-derived cyanate ester that does not have any reflectional symmetry.

Any suitable asymmetric bisphenol-derived cyanate ester may be used. For example, the asymmetric bisphenol-derived cyanate ester may be an asymmetric bisphenol-derived cyanate ester having a bridging unit that disrupts the crystallinity of the monomer rendering it either a liquid or a solid having a melting point below <NUM>.

The asymmetric bisphenol-derived cyanate ester may, for example, be one of the asymmetric bisphenol-derived cyanate esters disclosed in <NPL>.

For example, the asymmetric bisphenol-derived cyanate ester may be selected from bisphenol E dicyanate, p-cumylphenylcyanate (see Table <NUM> of "Chemistry and Technology of Cyanate Ester Resins cited above), the siloxane in Table <NUM> of "Chemistry and Technology of Cyanate Ester Resins cited above, diallylbisphenol A dicyanate and its dipropenyl analogue (see Table <NUM> of "Chemistry and Technology of Cyanate Ester Resins cited above), the fluoropolymers in Table <NUM> of "Chemistry and Technology of Cyanate Ester Resins cited above) and the monofunctional cyanates in Table <NUM> of "Chemistry and Technology of Cyanate Ester Resins cited above).

The asymmetric bisphenol-derived cyanate ester may, for example, be suitable for use as a reactive diluent to enhance the low temperature processability of the polyfunctional cyanate esters described herein.

The asymmetric bisphenol-derived cyanate ester may, for example, be a compound of formula (III) below:
<CHM>
wherein R<NUM> and R<NUM> are independently selected from hydrogen and C<NUM>-<NUM> alkyl, and R<NUM> and R<NUM> are different.

The asymmetric bisphenol-derived cyanate ester may, for example, be a compound of formula (Illa) below:
<CHM>
wherein R<NUM> and R<NUM> are independently selected from hydrogen and C<NUM>-<NUM> alkyl, and R<NUM> and R<NUM> are different.

For example, one of R<NUM> and R<NUM> may be hydrogen and the other of R<NUM> and R<NUM> may be C<NUM>-<NUM> alkyl (i.e. alkyl having between <NUM> and <NUM> carbon atoms). For example, one of R<NUM> and R<NUM> may be hydrogen and the other of R<NUM> and R<NUM> may be methyl or ethyl. For example, one of R<NUM> and R<NUM> may be hydrogen and the other of R<NUM> and R<NUM> may be methyl.

For example, the asymmetric bisphenol-derived cyanate ester may be bisphenol E dicyanate having the structure below:
<CHM>.

The asymmetric bisphenol-derived cyanate ester may, for example, be the material referred to as Primaset® LECy supplied by Lonza Group Limited, or the material referred to as AroCy® L-<NUM> low viscosity bisphenol-E based cyanate ester supplied by Huntsman Advanced Materials.

The composition of the first aspect of the invention, the cured resinous material of the second aspect of the invention, the composite material of the third aspect of the invention, and the articles of the fourth aspect of the invention may further comprise a reinforcing material.

As used herein, a "reinforcing material" is any material that increases any mechanical property of the composition of the first aspect after it has been cured.

For example, the composition of the first aspect of the invention, the cured resinous material of the second aspect of the invention, the composite material of the third aspect of the invention, and the articles of the fourth aspect of the invention may further comprise a nanomaterial.

As used herein, a "nanomaterial" is any material having one or more average dimensions in the range of <NUM> to <NUM>.

The nanomaterial may, for example, be selected from nanoparticles (e.g. alumina, silica, titania, boron nitride, aluminium nitride), metallic nanowhiskers, graphene (e.g. sheets, tubes, spheres), graphite, functionalised graphene (e.g. sheets, tubes, spheres), silicon nanotubes, and suitably functionalised polyhedral oligomeric silsequioxane (POSS) cages so as to render them co-reactive with the cyanate ester. The functionalised graphene may, for example, be functionalised with oxygen or carboxyl. The nanomaterial may, for example, be edge-oxidised graphene oxide.

The nanomaterial may, for example, be present in the composition of the first aspect in an amount equal to or less than about <NUM> wt%, based on the total dry weight of the composition. For example, the nanomaterial may be present in the composition in an amount equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, for example equal to or less than about <NUM> wt%, based on the total dry weight of the composition.

The nanomaterial may, for example, be present in the composition of the first aspect in an amount equal to or greater than about <NUM> wt%, based on the total dry weight of the composition. For example, the nanomaterial may be present in the composition in an amount equal to or greater than about <NUM> wt%, for example equal to or greater than about <NUM> wt%, based on the total dry weight of the composition.

For example, the nanomaterial may be present in the composition of the first aspect in an amount ranging from about <NUM> wt% to about <NUM> wt%, for example from about <NUM> wt% to about <NUM> wt%, for example from about <NUM> wt% to about <NUM> wt%, based on the total dry weight of the composition.

The composition according to the first aspect disclosed herein may, for example, comprise a compound of formula (I), a compound of formula (II), and a compound of formula (III). For example, the composition according to the first aspect disclosed herein may, for example, comprise bisphenol C (BPC), a compound of formula (II), and a compound of formula (III). The composition according to the first aspect disclosed herein may, for example, comprise a compound of formula (I), a compound of formula (II), and bisphenol E dicyanate.

The polyfunctional cyanate ester, the asymmetrical bisphenol-derived cyanate ester and the compound of formula (I) are present in the composition of the first aspect of the invention in any amount, provided that the total does not exceed <NUM> wt%, based on total dry weight of the composition.

The compound of formula (I) is present in the composition according to the first aspect of the invention in an amount ranging from <NUM> wt% to <NUM> wt%, for example from <NUM> wt% to <NUM> wt%, for example from <NUM> wt% to <NUM> wt%, based on the total dry weight of the composition.

The polyfunctional cyanate ester is present in the composition according to the first aspect in an amount ranging from <NUM> wt% to <NUM> wt%, for example from <NUM> wt% to <NUM> wt%, for example from <NUM> wt% to <NUM> wt%, based on the total dry weight of the composition.

The asymmetric bisphenol-derived cyanate ester is present in the composition of the first aspect in an amount ranging from <NUM> wt% to <NUM> wt% or from <NUM> wt% to <NUM> wt%, based on the total dry weight of the composition.

The composition of the first aspect of the invention may, for example, have a bulk viscosity equal to or less than about <NUM> cP at <NUM>. For example, the composition of the first aspect of the invention may have a bulk viscosity equal to or less than about <NUM> cP or equal to or less than about <NUM> cP at <NUM>. The composition of the first aspect of the invention may, for example, have a bulk viscosity equal to or greater than about <NUM> cP at <NUM>. For example, the composition of the first aspect of the invention may have a bulk viscosity equal to or greater than about <NUM> cP or equal to or greater than about <NUM> cP at <NUM>. For example, the composition of the first aspect of the invention may have a bulk viscosity ranging from about <NUM> cP to about <NUM> cP or from about <NUM> cP to about <NUM> cP or from about <NUM> cP to about <NUM> cP at <NUM>. Bulk viscosity may be measured by ASTM D4440-<NUM>.

The composition of the first aspect of the invention may, for example, have a dynamic rheology equal to or less than about <NUM> Pa. s at <NUM>. For example, the composition of the first aspect of the invention may have a dynamic rheology equal to or less than about <NUM> Pa. s or equal to or less than about <NUM> Pa. s or equal to or less than about <NUM> Pa. s or equal to or less than about <NUM> Pa. s at <NUM>. The composition of the first aspect of the invention may, for example, have a dynamic rheology equal to or greater than about <NUM> Pa. For example, the composition of the first aspect of the invention may have a dynamic rheology equal to or greater than about <NUM> Pa. s or equal to or greater than about <NUM> Pa. s or equal to or greater than about <NUM> Pa. s or equal to or greater than about <NUM> Pa. s at <NUM>. Dynamic rheology may be measured by ASTM D4440-<NUM>.

There is also disclosed herein a non-claimed method for making a composition according to the first aspect of the invention, the method comprising mixing a polyfunctional cyanate ester that is a novolac cyanate ester, an asymmetric bisphenol-derived cyanate ester, and a compound of formula (I). The components may be mixed in any suitable order. Any suitable mixing technique and/or equipment can be used. One or more of the components of the composition of the first aspect of the invention may be heated prior to weighing and/or prior to mixing with the other components to improve its viscosity and processability. For example, the polyfunctional cyanate ester and/or the asymmetric bisphenol-derived cyanate ester may be heated, for example to a temperature ranging from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>, for example about <NUM>, prior to weighing and/or mixing with the other components.

There is also disclosed herein a cured resinous material obtained by and/or obtainable by curing a composition according to the first aspect of the invention. There is further disclosed herein a non-claimed method of making said cured resinous material, the method comprising curing a composition according to the first aspect of the invention.

Without wishing to be bound by theory, it is thought that curing compositions comprising polyfunctional cyanate esters leads to crosslinking between the cyanate groups to form a network of oxygen-linked triazine rings (cyanurates) and bisphenol ethers. This structure is a result of cyclotrimerization of the -O-C≡N groups. The presence of reactive groups on other components of the composition of the first aspect of the invention may result in these components also becoming incorporated into the crosslinked structure of the cured resinous material. For example, the -O-C=N groups of the asymmetric bisphenol-derived cyanate ester may crosslink with -O-C=N groups in the polyfunctional cyanate ester and/or the asymmetric bisphenol-derived cyanate ester, for example to form oxygen-linked triazine rings. For example, the double bond and/or the -OH groups of the compound of formula (I) may crosslink with -O-C=N groups in the polyfunctional cyanate ester and/or the asymmetric bisphenol-derived cyanate ester. This may, for example, reduce the amount of hydrolysable residual cyanate ester and hydroxyl groups present in the cured resinous material.

The curing of the composition of the first aspect of the invention may, for example, result in a degree of curing equal to or greater than about <NUM> %. For example, the curing may result in a degree of curing equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %, for example equal to or greater than about <NUM> %.

The curing of the composition of the first aspect of the invention may, for example, result in a degree of curing equal to or less than about <NUM> %. For example, the curing may result in a degree of curing equal to or less than about <NUM> %, for example equal to or less than about <NUM> %, for example equal to or less than about <NUM> %, for example equal to or less than about <NUM> %.

For example, the curing of the composition of the first aspect of the invention may result in a degree of curing ranging from about <NUM> % to about <NUM> % or from about <NUM> % to about <NUM> % or from about <NUM> % to about <NUM> %.

Degree of curing may be measured by differential scanning calorimetry (DSC), running a dynamic scan from room temperature to <NUM> at a heating rate of <NUM>/min. Degree of curing is calculated using the following formula in which ΔHc is the curing exotherm enthalpy (J/g) and ΔHpc is the post-curing exotherm enthalpy (J/g).

The composition of the first aspect of the invention may, for example, be made and put into a mold prior to curing such that the cured resinous material has a desired shape.

The curing of the composition according to the first aspect of the invention may take place at a temperature equal to or greater than about <NUM>. For example, the curing of the composition according to the first aspect of the invention may take place at a temperature equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>.

The curing of the composition according to the first aspect of the invention may take place at a temperature equal to or less than about <NUM>. For example, the curing of the composition according to the first aspect of the invention may take place at a temperature equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>.

For example, the curing of the composition according to the first aspect of the invention may take place at a temperature ranging from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>.

The curing the composition according to the first aspect of the invention may take place in a number of different stages, which each occur at different temperatures and/or for different lengths of time. For example, the curing of the composition according to the first aspect of the invention may take place in two or three different stages, each of which occurring at a different temperature. The temperature of the curing may increase with each subsequent stage.

For example, the curing of the composition may take place in a first stage occurring at a temperature ranging from about <NUM> to about <NUM> for between about <NUM> minutes and about <NUM> hours, a second stage occurring at a temperature ranging from about <NUM> to about <NUM> for between about <NUM> hours and about <NUM> hours, and a third stage occurring at a temperature ranging from about <NUM> to about <NUM> for between about <NUM> minutes and about <NUM> hours.

The onset of polymerization (crosslinking) of the composition of the first aspect of the invention may, for example, be equal to or less than about <NUM>. For example, the onset of polymerization of the composition of the first aspect of the invention may be equal to or less than about <NUM>, for example equal to or less than about <NUM>. The onset of polymerization of the composition of the first aspect of the invention may, for example, be equal to or greater than about <NUM>, for example equal to or greater than about <NUM>. Onset of polymerization may, for example, be measured by differential scanning calorimetry (DSC) to measure a significant deflection from the baseline, running a dynamic scan from room temperature to <NUM> at a heating rate of <NUM>/min.

The curing of the composition of the first aspect of the invention may, for example, take place in the presence of a catalyst. The catalyst may, for example, comprise carboxylate salts and/or chelates of transition metals such as copper, zinc, manganese, cobalt or nickel, for example dissolved in a hydrogen-donating solvent such as an alkyl phenol. The curing of the composition of the first aspect of the invention may, for example, take place without any catalyst.

The composition of the first aspect of the invention may, for example, be degassed prior to curing. Degassing may occur at any temperature less than the temperature of onset of polymerisation for the particular composition. Degassing may occur at any temperature and for any period of time less than the period of time at which curing is initiated. For example, the degassing may occur at a temperature ranging from about <NUM> to about <NUM> for about <NUM> minutes to about <NUM> hour.

The cured resinous material may, for example, have a glass-transition temperature equal to or greater than about <NUM>. For example, the cured resinous material may have a glass-transition temperature equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>. For example, the cured resinous material may have a glass-transition temperature equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>. For example, the cured resinous material may have a glass-transition temperature ranging from about <NUM> to about <NUM> or from about <NUM> to about <NUM> or from about <NUM> to about <NUM> or from about <NUM> to about <NUM>.

The temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or greater than about <NUM>. For example, the temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>.

The temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>.

For example, the temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, range from about <NUM> to about <NUM> or from about <NUM> to about <NUM>.

The temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or greater than about <NUM>. For example, the temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>, for example equal to or greater than about <NUM>.

The temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, be equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>, for example equal to or less than about <NUM>.

For example, the temperature at which <NUM> wt% of the mass of the cured resinous material of the second aspect of the invention is lost may, for example, range from about <NUM> to about <NUM> or from about <NUM> to about <NUM> or from about <NUM> to about <NUM>.

The mass loss at particular temperatures (thermal stability) may be determined by thermogravimetric analysis (TGA) under air or nitrogen.

The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>. The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>. For example, the cured resinous material may have a moisture uptake after <NUM> hours ranging from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM> or from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM>.

The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>. The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>. For example, the cured resinous material may have a moisture uptake after <NUM> hours ranging from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM> or from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM>.

The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>, for example equal to or less than about <NUM> % cm-<NUM>. The cured resinous material of the second aspect of the invention may, for example, have a moisture uptake after <NUM> hours equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>, for example equal to or greater than about <NUM> % cm-<NUM>. For example, the cured resinous material may have a moisture uptake after <NUM> hours ranging from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM> or from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM> or from about <NUM> % cm-<NUM> to about <NUM> % cm-<NUM>.

Moisture uptake may be measured by ASTM D570-<NUM>.

There is also disclosed herein a composite material comprising a cured resinous material according to the second aspect of the invention. As used herein, a "composite material" is a material comprising two or more different materials that remain separate and distinct in the composite material, where the two or more different materials have different chemical and/or physical properties such that, when combined, produce a material that has properties different from the individual components. Thus, one component of the composite material disclosed herein is a cured resinous material as disclosed herein.

Another component of the composite material disclosed herein may, for example, be a reinforcing material as disclosed herein. The reinforcing material may, for example, be a nanomaterial.

There is also disclosed herein a non-claimed method for making a composite material, the method comprising combining a composition according to the first aspect of the invention with a reinforcing material followed by curing the resulting composition.

The curing process may, for example, be in accordance with the curing process described herein in relation to the cured resinous material.

The composite material may, for example, have one or more of the properties such as glass transition temperature, thermal stability and/or moisture uptake described herein in relation to the cured resinous material.

Any methods known to persons skilled in the art may be used to form the composite materials disclosed herein such as hot melt pre-preg methods, filament winding methods, and resin transfer molding (RTM) methods.

There is also provided herein an article comprising the cured resinous material of the second aspect of the invention and an article comprising the composite material according to the third aspect of the invention. As used herein, an "article" refers to a commercial product or object that comprises the cured resinous material of the second aspect of the invention and/or the composite material according to the third aspect of the invention. The article may therefore be in contact with one or more other materials.

The article may, e.g. be a product or object that is one part of a larger product or object.

The article may, for example, be any article that may benefit from a material having a low moisture uptake, high flame and smoke retardancy and/or high resistance to high temperatures.

The article may, for example, be a gas turbine engine component (e.g. a gas turbine shaft such as a compressor/fan shaft, a gearbox shaft, an auxiliary drive shaft), a generator component, a motor component, a compressor variable vane, a stator vane, a rotor blade, or an airframe structure (e.g. airframe structure of a high Mach number air vehicle). The article may, for example, be a component of a gas turbine engine.

The article may, for example, be comprised within an engine. The article may, for example, be comprised within an aircraft.

Primaset® PT-<NUM> (<NUM>) and Primaset® LECy (<NUM>) were purchased from Lonza AG (Visp, Switzerland) and were used as received. PT-<NUM> is an oligomeric phenolic cyanate (average relative molecular mass of <NUM> gmol-<NUM>). Bisphenol C (<NUM>, BPC) and Egde-oxidised graphene oxide (<NUM>, EOGO) were purchased from Sigma-Aldrich and Garmor Inc respectively and used as received. For clarity, each monomer is assigned a number, by which it will be referred throughout. In the case of blends, the notation [<NUM>x:<NUM>y] is used, where <NUM> and <NUM> are the assigned monomer numbers and x and y are their corresponding weight percentages in the blend composition.

The blends were prepared by weighing <NUM>, <NUM>, <NUM>, and <NUM> into a <NUM> custom made reaction vessel (without the lid) in the following ratios: <NUM><NUM>:<NUM><NUM>:<NUM><NUM>:<NUM><NUM> (Blend <NUM>) and <NUM><NUM>:<NUM><NUM>:<NUM><NUM> (Blend <NUM>) by weight and stirred using an overhead stirrer at <NUM> for <NUM> minutes (until a homogeneous blend was achieved). The resulting homogeneous blend was poured into the desired mould, in which it was degassed for <NUM> minutes at <NUM> in a vacuum oven. Resin samples were cured in a convection oven using the following cure cycle: <NUM> for <NUM> hour, <NUM> for <NUM> hours, and <NUM> for <NUM> hour. Owing to its viscosity, prior to weighing the Primaset® PT-<NUM> (<NUM>) it was heated to <NUM> for <NUM> minutes. To further assist the blending of the materials LECy was also melted at <NUM>.

Comparative compositions were made in a similar way using one or more of PT-<NUM>, LECy and diallyl bisphenol A (DBA).

Water uptake was determined by ASTM D570-<NUM>. Cured Resins were placed in round bottomed flasks half-filled with deionised water. The temperature of the water was monitored via the use of thermocouple connected to the carousel insert of a hot plate (to allow the use of more than one round bottomed flask being heated simultaneously). After the specified time periods, the resin blocks were taken out of the water, dried using a paper towel and weighed in a mass balance with readability up to <NUM>.

The results are shown in <FIG> and Table <NUM> below.

A number of resin blends were made as described in Example <NUM> above (but without curing).

Dynamic rheology of the resin blends was measured by ASTM D4440-<NUM>.

A number of resin blends were prepared as described above in Example <NUM> (but without curing).

Degree of curing was measured by differential scanning calorimetry (DSC), running a dynamic scan from room temperature to <NUM> at a heating rate of <NUM>/min. Degree of curing is calculated using the following formula in which ΔHc is the curing exotherm enthalpy (J/g) and ΔHpc is the post-curing exotherm enthalpy (J/g).

Onset of polymerization was measured by differential scanning calorimetry (DSC) to measure a significant deflection from the baseline, running a dynamic scan from room temperature to <NUM> at a heating rate of <NUM>/min.

Thermal stability was determined by thermogravimetric analysis (TGA) under air or nitrogen.

The results are shown in Tables <NUM> and <NUM> below.

Claim 1:
A composition comprising:
(a) a polyfunctional cyanate ester that is a novolac cyanate ester;
(b) an asymmetric bisphenol-derived cyanate ester; and
(c) a compound of formula (I):
<CHM>
wherein R<NUM> and R<NUM> are the same or different and are selected from hydrogen and halogen; and R<NUM>, R<NUM>, R<NUM> and R<NUM> are hydrogen; and
wherein the novolac cyanate ester is present in an amount of <NUM> wt% to <NUM> wt% based on the total dry weight of the composition, the asymmetric bisphenol-derived cyanate ester is present in an amount of <NUM> wt% to <NUM> wt% based on the total dry weight of the composition, and the compound of formula (I) is present in an amount of <NUM> wt% to <NUM> wt% based on the total dry weight of the composition, provided that the total does not exceed <NUM> wt%, based on total dry weight of the composition.