阅读说明：本技术 具有热塑性增韧的线型酚醛基环氧树脂基质的半浸料 (Semi-preg with thermoplastic toughened linear phenolic-based epoxy resin matrix ) 是由 K·L·巴伦 G·埃默森 Y-S·王 于 2018-12-04 设计创作，主要内容包括：公开了可以固化/模塑以形成包括火箭助推器壳体的航空航天复合部件的半浸料。半浸料包括纤维层和位于纤维层的一个侧面上的树脂层。树脂层包括环氧组分,环氧组分为烃线型酚醛环氧树脂和三官能的环氧树脂和任选的四官能的环氧树脂的组合。树脂基质包括热塑性颗粒组分和作为增韧剂的聚醚砜。(A prepreg that can be cured/molded to form aerospace composite parts including rocket motor casings is disclosed. The prepreg includes a fiber layer and a resin layer on one side of the fiber layer. The resin layer includes an epoxy component that is a combination of a hydrocarbon novolac epoxy resin and a trifunctional epoxy resin and optionally a tetrafunctional epoxy resin. The resin matrix includes a thermoplastic particulate component and polyethersulfone as a toughening agent.)

1. A semi-preg comprising:

A) a fibrous layer comprising carbon fibers, the fibrous layer comprising a first side and a second side, the fibrous layer having a thickness defined by a distance between the first side and the second side; and

B) a resin layer comprising an uncured resin on a first side of the fibrous layer, the uncured resin penetrating into the fibrous layer to an impregnation depth that is less than a thickness of the fibrous layer, the uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic particulate component;

c) a thermoplastic toughening agent; and

d) and (3) a curing agent.

2. The prepreg of claim 1, wherein the epoxy resin component comprises a tetrafunctional epoxy resin.

3. The semipreg according to claim 2, wherein the toughening agent is polyethersulfone.

4. A semi-preg according to claim 3, wherein the thermoplastic particle component comprises polyimide particles and particles comprising a polyamide which is the polymeric condensation product of 1, 10-decanedicarboxylic acid and an amine component having the formula

Wherein two R are₂Are all hydrogen, R₁Are both methyl or hydrogen.

5. A semi-preg according to claim 4, wherein the aromatic amine is 3,3' -diaminodiphenyl sulphone.

6. The prepreg according to claim 1, wherein the resin layer comprises:

A) a first portion of uncured resin on a first side of the fibrous layer, the first portion of uncured resin penetrating into the fibrous layer to an impregnation depth, the first portion of uncured resin being free of the thermoplastic particle component and having an outer boundary, the first portion of uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic toughening agent;

c) a curing agent;

B) a second portion of uncured resin located on an outer boundary of the first portion of uncured resin, the second portion of uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic particulate component;

c) a thermoplastic toughening agent; and

d) and (3) a curing agent.

7. An uncured rocket booster casing comprising the prepreg of claim 1.

8. A rocket booster casing comprising the semi-preg of claim 1, wherein the uncured resin has been cured.

9. An uncured rocket booster casing comprising the prepreg of claim 6.

10. A rocket booster casing comprising the semi-preg of claim 6, wherein the uncured resin of the first portion and the uncured resin of the second portion have been cured.

11. A method of preparing a semi-preg, the method comprising the steps of:

A) providing a fibrous layer comprising carbon fibers, the fibrous layer comprising a first side and a second side, the fibrous layer having a thickness defined by a distance between the first side and the second side; and

B) applying an uncured resin to a first side of the fibrous layer, the uncured resin penetrating into the fibrous layer to an impregnation depth that is less than the thickness of the fibrous layer, the uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic particulate component;

c) a thermoplastic toughening agent; and

d) and (3) a curing agent.

12. A method of preparing a prepreg according to claim 11 wherein the epoxy resin component comprises a tetrafunctional epoxy resin.

13. The method of making a prepreg according to claim 12 wherein the toughening agent is polyethersulfone.

14. A method of making a prepreg according to claim 13 wherein the thermoplastic particle component comprises polyimide particles and particles comprising a polyamide which is the polymeric condensation product of 1, 10-decanedicarboxylic acid and an amine component having the formula

Wherein two R are₂Are both hydrogen, two R₁Are both methyl or hydrogen.

15. A method of making a semi-preg according to claim 14, wherein the aromatic amine is 3,3' -diaminodiphenyl sulphone.

16. A method of preparing a semi-preg according to claim 10, wherein the step of applying an uncured resin to the first side of the fibre layer comprises:

A) applying a first portion of uncured resin to a first side of the fibrous layer, the first portion of uncured resin penetrating into the fibrous layer to the depth of impregnation, the first portion of uncured resin being free of the thermoplastic particle component and having an outer surface, the first portion of uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic toughening agent;

c) a curing agent;

B) applying a second portion of uncured resin to an outer surface of the first portion of uncured resin, the second portion of uncured resin comprising:

a) an epoxy resin component comprising a hydrocarbon novolac epoxy resin and a triglycidyl aminophenol epoxy resin;

b) a thermoplastic particulate component;

c) a thermoplastic toughening agent; and

d) and (3) a curing agent.

17. The method according to claim 11, comprising the further step of: forming the semi-preg into an uncured rocket case, and curing the uncured resin to form a cured rocket case.

18. The method of claim 16, comprising the further step of: forming the semi-preg into an uncured rocket case, and then curing the first portion of uncured resin and the second portion of uncured resin to form a cured rocket case.

19. A method of manufacturing a rocket case, comprising the steps of: providing an uncured rocket motor case comprising a prepreg according to claim 1, and curing said uncured resin to form said rocket case.

20. A method of manufacturing a rocket case, comprising the steps of: providing an uncured rocket motor case comprising a prepreg according to claim 6, and curing said uncured resin to form said rocket case.

Technical Field

The present invention relates generally to pre-impregnated composite materials (prepregs) for use in the manufacture of high performance composite parts particularly suitable for use as aerospace components. The present invention relates to linear phenolic-based epoxy resins toughened with thermoplastic materials and used as resin matrices in such prepregs. More particularly, the present invention relates to prepregs comprising a thermoplastic toughened epoxy resin matrix consisting of a novolac epoxy resin and a triglycidyl aminophenol epoxy resin.

Background

Composite materials are generally composed of a resin matrix and reinforcing fibers as two major constituent components. Composite materials are often required to be performed in harsh environments, such as in the aerospace field, where the physical limits and characteristics of the composite part are critical.

Pre-impregnated composite materials are widely used in the manufacture of composite parts. Prepregs are a combination typically comprising uncured resin and fibre reinforcement in a form ready for moulding and curing into a final composite part. By pre-impregnating the fibrous reinforcement with resin, the manufacturer can carefully control the amount and location of resin impregnation into the fibrous network and ensure that the resin distributes the resin into the network as desired. It is well known that the relative amounts of fibers and resin in a composite part and the distribution of resin in the fiber network can affect the structural properties of the part.

Prepregs are used in the manufacture of spacecraft (rocket boosters and spacecraft) and load-bearing or primary aircraft structural components, such as wings, fuselages, bulkheads and control surfaces. It is important that these components have sufficient strength, damage tolerance, and other requirements that are routinely established for these components and structures.

The fibrous reinforcement material typically used in aerospace prepregs is a multidirectional woven or unidirectional tape comprising fibres extending parallel to each other. The fibers are typically in the form of a bundle of a large number of individual fibers or filaments, which is referred to as a "tow". The fibers or tows may also be chopped and randomly oriented in the resin to form a nonwoven mat. These various fiber reinforcement configurations are combined with carefully controlled amounts of uncured resin. The resulting prepreg is typically placed between protective layers and rolled up for storage or transport to production facilities. The combination of carbon fibers and an epoxy resin matrix has become a popular combination of aerospace prepregs.

The prepreg may also be in the form of short segments of randomly oriented chopped unidirectional tape to form a non-woven mat of chopped unidirectional tape. This type of prepreg is referred to as a "quasi-isotropic chopped" prepreg. Quasi-isotropic chopped prepreg is similar to more traditional non-woven fiber mat prepreg except that the short lengths of chopped unidirectional tape (chips) are randomly oriented in the mat rather than in the chopped fibers. The material is typically used as a sheet molding compound to form parts and molds for making parts.

The compressive and tensile strength of the cured composite part is controlled primarily by: the respective properties of the reinforcing fibers and the matrix resin, and the interaction between these two components. Furthermore, the fiber-resin volume ratio is an important factor. In many aerospace applications, it is desirable that composite parts exhibit high compressive and tensile strength. Open Hole Compression (OHC) test is a standard measure of the compressive strength of a composite material. Open Hole Tensile (OHT) test is also a standard measure of the tensile strength of composites.

In many aerospace applications, it is desirable that composite parts exhibit high compressive and/or tensile strength under both room temperature/dry conditions and hot/wet conditions. However, attempts to maintain high compressive and tensile strengths often adversely affect other desirable properties such as damage tolerance and interlaminar fracture toughness.

The selection of higher modulus resins may be an effective way to increase the compressive strength of the composite. However, this tends to result in a reduction in damage tolerance, which is typically measured by a reduction in compression properties such as post impact Compression (CAI) strength. Thus, it is very difficult to achieve simultaneous improvement in both compressive strength and/or tensile strength without adversely affecting damage tolerance.

Multilayer prepregs are commonly used to form composite parts having a laminar structure. Delamination of such composite parts is an important failure mode. Delamination occurs when two layers debond from each other. Important design constraints include both the energy required to initiate delamination and the energy required to diffuse delamination. The onset and development of delamination is generally determined by examining the mode I and mode II fracture toughness. Fracture toughness is typically measured using a composite material having unidirectional fiber orientation. The interlaminar fracture toughness of the composites was quantified using the G1c (Double Cantilever Beam) and/or G2c (End notch flex) tests. In mode I, the pre-split laminate failed with respect to peel force, and in mode II, the split was propagated by shear force.

One way to improve the interlaminar fracture toughness of components made from carbon fiber/epoxy prepregs has been to introduce thermoplastic sheets as interleaf layers between prepreg layers. However, this approach tends to result in hard, tack-free materials that are difficult to use. Another approach has been to add thermoplastic particles to the epoxy resin such that a resin interlayer containing the thermoplastic particles is formed between the fiber layers of the final part. Polyamides have been used as such thermoplastic particles. It is also known to include thermoplastic toughening agents in epoxy resins. A toughening agent such as Polyethersulfone (PES) or Polyetherimide (PEI) is dissolved in the epoxy resin prior to application to the carbon fibers. Thermoplastic toughened epoxy resins, including a combination of both thermoplastic toughening particles and thermoplastic toughening agents, have been used in combination with carbon fibers to make aerospace prepregs.

The epoxy matrix may include one or more types of epoxy. It is known that various combinations of different types of epoxy resins can result in a wide variation in the properties of the final composite part. The curing agent used to cure the epoxy resin matrix can also significantly affect the properties of the final composite part. When formulating epoxy resins for use as resin matrices in aerospace prepregs, it is difficult to anticipate whether a new combination of epoxy resin type and curing agent will also provide the desired combination of properties required for aerospace components. This is particularly the case when the thermoplastic toughening agent and thermoplastic particles form part of an epoxy resin formulation. Therefore, extensive testing was involved when attempting to formulate new thermoplastic toughened epoxy resins in order to determine whether the resins are suitable for use as resin matrices in aerospace prepregs.

While existing aerospace prepregs are well suited for their intended use in providing strong and damage tolerant composite parts, there is a continuing need to provide aerospace prepregs that can be used to make composite parts that exhibit the desired combination of high tensile and compressive strength (OHC and OHT) while maintaining a high level of damage tolerance (CAI) and interlaminar fracture toughness (G1c and G2 c).

Disclosure of Invention

In accordance with the present invention, pre-impregnated composite materials (prepregs) are provided that can be molded to form composite parts having a high level of strength and a high level of damage tolerance and interlaminar fracture toughness.

The pre-impregnated composite material of the present invention is comprised of reinforcing fibers and an uncured resin matrix. The uncured resin matrix includes a resin component that is comprised of: novolac epoxy resins and triglycidyl aminophenol epoxy resins or combinations of triglycidyl aminophenol epoxy resins and tetrafunctional epoxy resins. The uncured resin matrix further includes a thermoplastic particle component, a thermoplastic toughening agent, and a curing agent.

The invention also includes methods for making the prepregs and methods for molding the prepregs into a wide variety of composite parts. The invention also includes composite parts made using the improved prepregs.

It has been found that resins having the above-described matrix resin formulation can be used to form prepregs that can be molded to form composite parts having an unexpectedly high level of interlaminar fracture toughness.

The above-described and many other features of the present invention, along with the attendant advantages, will be best understood by reference to the following detailed description when considered in connection with the accompanying drawings.

Drawings

FIG. 1 is a perspective view of an aircraft depicting an exemplary primary aircraft structure that may be produced using a composite material according to the present invention.

FIG. 2 is a partial view of a helicopter rotating blade depicting an exemplary primary aircraft structure that may be produced using a composite material according to the present invention.

Figure 3 is a side view of a spacecraft comprised of a rocket booster and an aircraft.

FIG. 4 is a simplified cross-sectional view of the rocket booster portion of the spacecraft showing a cylindrical rocket booster housing.

FIG. 5 is a schematic representation of an exemplary method of preparing an autoclave overmolded prepreg (prepreg) for rocket motor casings.

Fig. 6 is a simplified illustration of an exemplary prepreg in which the resin matrix has been applied as a single film or layer.

Fig. 7 is a simplified illustration of an exemplary prepreg in which the resin matrix has been applied as two films or layers.

Fig. 8 shows a portion of an exemplary prepreg layup during out-of-autoclave curing in a vacuum bag.

Detailed Description

The uncured epoxy resin composition according to the present invention can be used in numerous situations where a thermoplastic toughened epoxy resin matrix is required. While the uncured epoxy resin composition may be used alone, the composition is typically used as a matrix resin that is combined with a fibrous support to form a fibrous material comprised of the fibrous support and a resin matrix. The composite material may be in the form of a prepreg, a partially cured prepreg or a fully cured final part. The term "uncured" when used herein in connection with a prepreg, a resin prior to impregnation into a fibrous support, a resin matrix formed when impregnating a fibrous support with a resin, or a composite material is intended to include the following: it may undergo some curing, but it is not fully cured to form the final composite part or structure.

While the uncured composite materials may be used for any intended purpose, they are preferably used to prepare parts of aerospace vehicles, such as commercial or military aircraft and rocket motor shells. For example, the uncured composite material may be used to make non-primary (secondary) aircraft structures. However, a preferred use of the uncured composite material is for structural applications, such as primary aircraft structures. Primary aircraft structures or components are those elements of fixed-wing or rotary-wing aircraft that experience significant stresses during flight and are necessary for the aircraft to maintain controlled flight. The uncured composite material may also be used in other structural applications, typically for making load bearing members and structures.

FIG. 1 depicts at 10 a fixed wing aircraft including exemplary primary aircraft structures and components that may be prepared using uncured composite materials according to the present invention. Exemplary primary components or structures include a wing 12, a fuselage 14, and a tail assembly 16. The wing 12 includes a number of exemplary primary aircraft components, such as ailerons 18, a wing leading edge 20, a wing slat 22, a spoiler 24, a wing trailing edge 26, and a trailing edge flap 28. Tail assembly 16 also includes a plurality of exemplary primary components, such as rudder 30, fins 32, horizontal stabilizers 34, elevators 36, and tail 38. FIG. 2 depicts an outer end portion of a helicopter rotating blade 40 that includes a spar 42 and an outer surface 44 that are primary aircraft structures. Other exemplary primary aircraft structures include spars, and a plurality of flanges, clips, and connectors that connect the primary components together to form the primary structure.

The pre-impregnated composite material (prepreg) of the present invention may be used as a substitute for existing prepregs for forming composite parts in the aerospace industry and any other application where high structural strength and damage tolerance are required. The present invention includes replacing existing resins used to make prepregs with the resin formulations of the present invention. Thus, the resin formulation of the present invention is suitable for use as a matrix resin in conventional prepreg manufacturing and curing processes.

The pre-impregnated composite material of the present invention is comprised of reinforcing fibers and an uncured resin matrix. The reinforcing fibers may be any conventional fiber construction used in the prepreg and composite sheet molding industry. Carbon fibers are preferably used as the reinforcing fibers.

The resin (matrix resin) for forming the resin matrix includes a resin component composed of: a hydrocarbon novolac epoxy resin in combination with a trifunctional epoxy resin and optionally a tetrafunctional epoxy resin. The matrix resin further includes a thermoplastic particle component, a thermoplastic toughening agent, and a curing agent.

The hydrocarbon novolac epoxy resin preferably has a dicyclopentadiene backbone and is commercially available as TACTIX556 from Huntsman Corporation (The Woodlands, TX). This type of hydrocarbon novolac resin is referred to herein as dicyclopentadiene novolac epoxy resin. TACTIX556 has a chemical formula of

TACTIX556 is an amber to dark colored semi-solid hydrocarbon novolac epoxy resin having an epoxy resin (ISO3001) of 4.25 to 4.65eq/kg, an epoxy equivalent (ISO3001) of 215-235 g/eq.TACTIX 556 having a viscosity at 79 ℃ (ISO 9371B) of 2250mPa s.A dicyclopentadiene novolac epoxy resin other than TACTIX556 may be used in place of TACTIX556 provided that they have the same chemical formula and properties, for example, another suitable dicyclopentadiene novolac epoxy resin is XD-1000-2L commercially available from Nippon Kayaku Co., L tda (Chiyoda-ku, Tokyo) TACTIX556 is the preferred hydrocarbon novolac epoxy resin used according to the present invention.

When a tetrafunctional epoxy resin is included in the resin component, the amount of hydrocarbon novolac epoxy resin present in the uncured resin may be from 8 to 20 weight percent, based on the total weight of the uncured resin matrix. Preferably, the uncured resin will comprise from 10 to 17 weight percent of the dicyclopentadiene novolac epoxy resin. Uncured resin formulations containing 13 to 15 wt% of dicyclopentadiene novolac epoxy resin are particularly preferred because they provide an unexpectedly high G2c of about 13 when the ratio of polyimide particles to polyamide particles is 3.2:1 to 2.8:1. In this embodiment of the invention, which is referred to herein as a DEN/TRIF/TETF matrix resin, the uncured resin component is comprised of a dicyclopentadiene novolac epoxy resin, a trifunctional epoxy resin, and a tetrafunctional epoxy resin.

Among The DEN/TRIF/TETF matrix resins, a preferred exemplary trifunctional epoxy resin is triglycidyl p-aminophenol, triglycidyl p-aminophenol is commercially available from huntsman advanced Materials (The Woodlans, TX) under The commercial name Araldite MY0510 Another suitable trifunctional epoxy resin is triglycidyl M-aminophenol, triglycidyl M-aminophenol is commercially available from huntsman advanced Materials (The Woodlans, TX) under The commercial name Araldite MY0600 and from Sumitomo chemical Co. (Osaka, Japan) under The commercial name E L M-120.

In The DEN/TRIF/TETF matrix resin embodiment, an exemplary tetrafunctional epoxy resin is N, N, N ', N ' -tetraglycidyl-4, 4' -diaminodiphenylmethane (TGDDM), which is commercially available as Araldite MY720 and MY721 from Huntsman Advanced Materials (The Woodlands, TX), or E L M434 from Sumitomo chemical industries, &lTtTtranslation = L "&gg L &lTtTtTtTtTtd. (Chuo, Tokyo).

In the DEN/TRIF/TETF matrix resin, the total amount of trifunctional epoxy resin and tetrafunctional epoxy resin may be 35 to 45 wt%, based on the total weight of the uncured resin. Preferably, the weight ratio of trifunctional epoxy to tetrafunctional epoxy is from 1.0:1.5 to 1.5: 1.0. It is particularly preferred that the weight ratio of trifunctional epoxy resin to tetrafunctional epoxy resin is from 1.1:1.0 to 1.3: 1.0.

In another embodiment of the invention, the resin component comprises only dicyclopentadiene novolac epoxy resin and triglycidyl aminophenol epoxy resin. In the resin component of this embodiment (which is referred to herein as the DEN/TRIF matrix resin), the dicyclopentadiene novolac epoxy resin is present in an amount ranging from 4 wt% to 30 wt%, based on the total weight of the uncured resin matrix. Preferably, the dicyclopentadiene novolac epoxy resin is present in an amount ranging from 17 wt% to 27 wt%, based on the total weight of the uncured resin matrix. More preferably, the dicyclopentadiene novolac epoxy resin is present in an amount ranging from 20 wt% to 24 wt%, based on the total weight of the uncured resin matrix.

In the DEN/TRIF matrix resin, the triglycidyl aminophenol epoxy resin is present in the range of 20 wt% to 55 wt%, based on the total weight of the uncured resin matrix. Preferably, the triglycidyl aminophenol epoxy resin is present in the range of from 26 weight percent to 36 weight percent based on the total weight of the uncured resin matrix. More preferably, the triglycidyl aminophenol epoxy resin is present in the range of from 29 to 33 weight percent based on the total weight of the uncured resin matrix. Triglycidyl meta-aminophenol is a preferred type of triglycidyl aminophenol epoxy resin for the DEN/TRIF matrix resin.

The weight ratio of triglycidyl aminophenol epoxy resin to dicyclopentadiene novolac epoxy resin in the DEN/TRIF matrix resin may be from 1:1 to 10.5: 1. The preferred weight ratio of triglycidyl aminophenol epoxy resin to dicyclopentadiene novolac epoxy resin is from 1.2:1 to 1.6: 1. Most preferably, the weight ratio of triglycidyl aminophenol epoxy resin to dicyclopentadiene novolac epoxy resin is about 1.4: 1.

The uncured resin matrix according to the invention also includes a thermoplastic particle component comprising one or more types of thermoplastic particles. Exemplary thermoplastic particles are polyamide particles formed from the polymeric condensation product of a methyl derivative of bis (4-aminocyclohexyl) methane and an aliphatic dicarboxylic acid selected from decanedicarboxylic acid and dodecanedicarboxylic acid. The methyl derivative of bis (4-aminocyclohexyl) methane is referred to herein as the "amine component", which is also referred to as the methyl derivative of 4,4' -diaminocyclohexylmethane. Polyamide particles of this type and their method of preparation are described in detail in us patents 3,936,426 and 5,696,202, the contents of which are incorporated herein by reference.

The amine component of the polymeric condensation product has the formula

Wherein R is₂Is hydrogen, R₁Is methyl or hydrogen.

The chemical formula of the monomer units of the polymeric condensation product is shown below:

the number of molecules of the polymeric condensation product will be between 14,000 and 20,000, with a preferred number of molecules being about 17,000.

The particle size of the polyamide particles should be below 100 microns. Preferably, the particles have a size of 5 to 60 microns, more preferably 10 to 30 microns. Preferably, the average particle size is 15 to 25 microns. The polyamide particles may be regular or irregular in shape. For example, the particles may be substantially spherical, or they may be particles having a saw-tooth shape.

An exemplary polyamide particle is prepared from a polyamide wherein the amine component of the polymeric condensation product has the formula wherein R is₁Are all methyl, R₂Are all hydrogen. Such polyamide particles may be prepared from the polymeric condensation product of 3,3' -dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid. The polyamide particles were prepared as follows: 13,800 grams of 1, 10-decanedicarboxylic acid and 12,870 grams of 3,3' -dimethyl-bis (4-aminocyclohexyl) -methane were combined with 30 grams of 50% aqueous phosphoric acid, 150 grams of benzoic acid and 101 grams of water in a heated receiving vessel. The mixture was stirred in the autoclave until homogeneous. After the compression, decompression and degassing stages, the polyamide condensation product is extruded as a strand, passed under cold water and granulated to form polyamide granules. Wherein R is₁Are both methyl and R₂Polyamide particles, both hydrogen, can also be prepared from GRI L AMID TR90, commercially available from EMS-Chime (Sumter, SC). GRI L AMID TR90 is the polymeric condensation product of 3,3' -dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid.

Another exemplary polyamide particle is prepared from a polyamide wherein the amine component of the polymeric condensation product has the formula wherein R is₁Are both hydrogen and R₂Are all hydrogen. Such polyamide particles can be prepared in the same manner as described above, except that the polyamide is 3,3' -bis (4-)Polymeric condensation products of aminocyclohexyl) -propane and 1, 10-decanedicarboxylic acid. Wherein R is₁Are both hydrogen and R₂Polyamide particles, both hydrogen, may also be prepared from CX7323, which is commercially available from Evonik (Mobile, A L). CX7323 is the polymeric condensation product of 3,3' -bis (4-aminocyclohexyl) -propane and 1, 10-decanedicarboxylic acid mixtures of the two exemplary polyamide particles may be used if desired.

The thermoplastic particle component may include one or more types of polyamide particles commonly used for thermoplastic toughened epoxy resins including, for example, Polyamide (PA)11, PA6, PA12, PA6/PA12 copolymer, PA4, PA8, PA6.6, PA4.6, PA10.10, PA6.10, and PA 10.12.

Preferred thermoplastic particulate components comprise: a first set of polyamide particles not comprising crosslinked polyamide, and a second set of polyamide particles comprising crosslinked polyamide.

A first group of polyamide particles may be any polyamide particles comprising a crosslinked polyamide and typically used for thermoplastic toughening of epoxy-based prepregs, such particles consisting of Polyamide (PA)11, PA6, PA12, PA6/PA12 copolymer, PA4, PA8, PA6.6, PA4.6, PA10.10, PA6.10 and PA 10.12. non-crosslinked polyamide particles are commercially available from a number of sources suitable non-crosslinked polyamide 12 particles are commercially available under the name SP 10L from Kobo products SP10L may comprise more than 98 wt% of PA 12. the particle size distribution is from 7 microns to 13 microns, with an average particle size of 10 microns. the density of the particles is 1g/cm³. Preferably, the PA12 particles are at least 95 wt% PA12, excluding moisture content.

Other suitable non-crosslinked particles are available from Arkema (Colombes, France) under the commercial designations Orgasol 1002 powder and Orgasol 3803 powder. The Orgasol 1002 powder consists of 100% of PA6 particles with an average particle size of 20 μm. Orgasol 3803 consisted of particles with an average particle size of 17 to 24 microns, 80% PA12 and 20% copolymer. Orgasol 2002 is a powder consisting of non-crosslinked PA12 particles that can also be used for the first set of particles.

Preferred non-crosslinked polyamides of the first group of thermoplastic particlesThe particles are polyamide 11 particles, which are also commercially available from a variety of sources. Preferred polyamide 11 particles are available from Arkema (Colombes, France) under the commercial name Rislan PA 11. These particles contain more than 98 wt% PA11 and the particle distribution is 15 to 25 microns. The average particle size was 20 microns. Rislan PA11 pellets had a density of 1g/cm³. Preferably, the PA11 particles are at least 95 wt% PA11, excluding moisture content.

The second group of thermoplastic polyamide particles are particles comprising crosslinked polyamide on the surface of the particles, crosslinked polyamide inside the particles, or both. The crosslinked polyamide particles may be prepared from polyamide that has been crosslinked prior to particle formation, or the non-crosslinked polyamide particles may be treated with a suitable crosslinking agent to prepare crosslinked polyamide particles.

Suitable crosslinked particles comprise crosslinked PA11, PA6, PA12, PA6/PA12 copolymer, PA4, PA8, PA6.6, PA4.6, PA10.10, PA6.10 and PA 10.12. Any crosslinking agent generally used to crosslink polyamides is suitable. Suitable crosslinkers are crosslinkers based on epoxy resins, crosslinkers based on isocyanates, crosslinkers based on carbodiimides, crosslinkers based on acyllactams and crosslinkers based on acyllactamsA crosslinking agent of oxazoline. A preferred crosslinked particle is a PA12 particle comprising PA12 crosslinked with an epoxy crosslinker. Processes for crosslinking thermoplastic polymers, including polyamides, are known. See, for example, U.S. patent 6399714, U.S. patent 8846818, and U.S. published patent application US 2016/0152782 a 1. The contents of these three references are incorporated into this application by reference.

Particles of cross-linked PA12 are commercially available from Arkema (Colombes, France) under the commercial name ORGASO L2009 polyamide powder, which is also known as cg352. the PA12 particles present in the ORGASO L2009 polyamide powder consist of at least 40% PA12, which has been cross-linked with an epoxy-based cross-linking agent the average particle size of the polyamide particles cross-linked by ORGASO L2009 is 14.2 microns, of which only 0.2% of the particles have a diameter greater than 30 microns the melting point of the particles cross-linked by ORGASO L2009 is 180 ℃. the specific surface area of the ORGASO L2009 particles is 1.9, the moisture content of the particles is 0.34%.

The crosslinked polyamide particles should contain 40 to 70% crosslinked polyamide. Preferably, the crosslinked polyamide particles should each comprise 40 to 60% crosslinked polyamide.

Preferably, the particle size of both the non-crosslinked polyamide particles and the crosslinked polyamide particles should be below 100 microns. Preferably, the particles are 5 to 60 microns in size, more preferably 5 to 30 microns. Preferably, the average particle size is 5 to 20 microns. The shape of the particles may be regular or irregular. For example, the particles may be substantially spherical, or they may be particles having a saw-tooth shape. Preferably, the non-crosslinked particles have a larger average particle size than the crosslinked particles. Preferably, the average non-crosslinked particle size will be from 15 to 25 microns and the average crosslinked particle size will be from 10 to 20 microns.

The thermoplastic particulate component is present in a range of 5 wt% to 20 wt%, based on the total weight of the uncured resin matrix. Preferably, from 7 to 17 wt% of the thermoplastic particulate component will be present. When a combination of crosslinked and non-crosslinked particles is used, the relative amounts of non-crosslinked and crosslinked particles may vary. The weight ratio of non-crosslinked particles to crosslinked particles can be from 4:1 to 1.5:1. Preferably, the weight ratio of non-crosslinked particles to crosslinked particles will be from 3.5:1 to 2.5:1. The combination of non-crosslinked and crosslinked particles is a preferred thermoplastic particle component for the DEN/TRIF matrix resin embodiment.

In the DEN/TRIF matrix resin embodiment, the total amount of polyamide particles in the uncured resin may vary from 9 to 21 wt%, based on the total weight of the uncured resin. Preferably, the total amount of polyamide particles in the uncured resin will be from 11 wt% to 19 wt%, based on the total weight of the uncured resin matrix. More preferably, the total amount of polyamide particles in the uncured resin will be from 12 wt% to 17 wt%, based on the total weight of the uncured resin matrix.

The thermoplastic particle component may comprise a combination of polyimide particles and polyamide particles, wherein the polyamide particles are comprised of a polymeric condensation product of a methyl derivative of bis (4-aminocyclohexyl) methane and an aliphatic dicarboxylic acid. This particulate combination is a preferred thermoplastic particulate component for the DEN/TRIF/TETF matrix resin embodiment.

Preferred polyimide particles are commercially available as P84 polyimide molding powder from HP Polymer GmbH (L enzig, Austria.) suitable polyamide particles are also commercially available under the trade designation P84NT from Evonik Industries (Austria.) polyimide for making particles is disclosed in U.S. Pat. No. 3,708,458, the disclosure of which is incorporated herein by reference.

The polyimide particles are comprised of an aromatic polyimide having repeating monomers of the formula:

wherein 10 to 90% of the R groups in the total polymer are aromatic groups having the formula:

the remainder of R in the polymer being

The polyimide particles are typically 2 to 35 microns in size in the powder. Preferred polyimide powders will contain particles having a size of 2 to 30 microns and an average particle size of 5 to 15 microns. Preferably, at least 90 wt% of the polyimide particles in the powder will be of a size of 2 to 20 microns. The shape of the polyimide particles may be regular or irregular. For example, the particles may be substantially spherical, or they may be particles having a saw-tooth shape.

The polyimide particles comprise at least 95 wt% polyimide. Small amounts (up to 5 wt%) of other materials may be included in the particles provided that they do not adversely affect the overall characteristics of the particles.

The glass transition temperature (Tg) of the polyimide particles should be about 330 ℃ with the density of the individual particles being 1.34 grams per cubic centimeter. The linear thermal expansion coefficient of the particles was 50.

The total amount of thermoplastic particles in the uncured DEN/TRIF/TETF matrix resin embodiment is preferably from 9 to 15 wt%, based on the total weight of the uncured resin. To obtain high delamination resistance, the weight ratio of polyamide particles to polyimide particles may be 3.5:1.0 to 1.0: 1.0. Preferably, the weight ratio of polyamide particles to polyimide particles is from 3.2:1.0 to 2.8: 1.0. In a particularly preferred DEN/TRIF/TETF matrix resin, the amount of polyimide particles is from 8 to 10 weight percent, based on the total weight of the uncured resin, and the amount of polyamide particles is from 2 to 4 weight percent, based on the total weight of the uncured resin.

The uncured resin matrix includes at least one curing agent. Suitable curing agents are those which promote curing of the epoxy-functional compounds of the present invention, and in particular promote ring-opening polymerization of such epoxy compounds. In a particularly preferred embodiment, such curing agents include those compounds that polymerize with one or more epoxy-functional compounds in their ring-opening polymerization. Two or more such curing agents may also be used in combination.

Suitable curing agents include Anhydrides, particularly polycarboxylic Anhydrides such as Nadic Anhydride (NA), nadic methyl Anhydride (MNA-available from Aldrich), phthalic Anhydride, tetrahydrophthalic Anhydride, hexahydrophthalic Anhydride (HHPA-available from Anhydrides and Chemicals Inc., Newark, N.J.), methyltetrahydrophthalic Anhydride (MTHPA-available from Anhydrides and Chemicals Inc.), methylhexahydrophthalic Anhydride (MHHPA-available from Anhydrides and Chemicals Inc.), endomethylenetetrahydrophthalic Anhydride, hexachloroendomethylenetetrahydrophthalic Anhydride (Chlorentic Anhydride-available from Velsicol Chemical Corporation, Rosemont, Ill.), trimellitic Anhydride, pyromellitic dianhydride, maleic Anhydride (MA-available from Aldrich), Succinic Anhydride (SA), nonenylsuccinic Anhydride, dodecenylsuccinic Anhydride (SA-available from Anhydrides and Inc., polysebacic anhydride, and polyazelaic anhydride.

Other suitable curing agents are amines, including aromatic amines, such as 1, 3-diaminobenzene, 1, 4-diaminobenzene, 4,4' -diamino-diphenylmethane, and polyaminosulfones, such as 4,4' -diaminodiphenyl sulfone (4,4' -DDS-available from Huntsman), 4-aminophenyl sulfone, and 3,3' -diaminodiphenyl sulfone (3,3' -DDS). Likewise, suitable curing agents may include polyols such as ethylene glycol (EG-available from Aldrich), poly (propylene glycol), and poly (vinyl alcohol); and phenolic resins such as phenol-formaldehyde resin having an average molecular weight of about 550-. As the phenolic resin, a combination of CTU guanamine and a phenolic resin having a molecular weight of 398, which is available as CG-125 from Ajinomoto USA Inc (teatech, n.j.), may also be used.

Compositions commercially available from various sources may be present in the present invention as curing agents. One such composition is AH-154, a dicyandiamide type formulation, available from Ajinomoto USA Inc. Other suitable compositions include: ancamide400, which is a mixture of polyamide, diethyltriamine, and triethylenetetramine; ancamide 506, which is a mixture of amidoamine, imidazoline, and tetraethylenepentamine; and Ancamide 1284, which is a mixture of 4,4' -methylenedianiline and 1, 3-phenylenediamine; these formulations are available from Pacific Anchor Chemical, Performance Chemical Division, Air Products and Chemicals, Inc., Allentown, Pa.

Additional suitable curing agents include imidazole (1, 3-diaza-2, 4-cyclopentadiene) available from Sigma Aldrich (St. L ouis, Missouri), 2-ethyl-4-methylimidazole available from Sigma Aldrich, and boron trifluoride amine complexes, such as Anchor 1170, available from Air Products & Chemicals, Inc.

Still further suitable curing agents include 3, 9-bis (3-aminopropyl-2, 4,8, 10-tetraoxaspiro [5.5] undecane, commercially available as ATU from Ajinomoto USA Inc., and aliphatic dihydrazides, commercially available as Ajicure UDH, also from Ajinomoto USA Inc., and mercapto-terminated polysulfides, commercially available as L P540 from Morton International, Inc., Chicago, Ill.

The curing agent is selected such that it cures the matrix at a suitable temperature. The amount of curing agent required to provide sufficient curing of the matrix will vary depending on a number of factors, including the type of resin to be cured, the desired curing temperature and curing time. Curing agents may also generally include cyanoguanidines, aromatic and aliphatic amines, anhydrides, lewis acids, substituted ureas, imidazoles, and hydrazines. The specific amount of curing agent required for each particular case can be determined by well-established routine experimentation.

Exemplary preferred curing agents include 4,4 '-diaminodiphenyl sulfone (4,4' -DDS) and 3,3 '-diaminodiphenyl sulfone (3,3' -DDS), both commercially available from Huntsman.

The curing agent is present in an amount of 10 to 30 weight percent of the uncured resin matrix. In the DEN/TRIF matrix resin, the curing agent is present in an amount of 17 to 27 weight percent. More preferably, the curing agent is present in the range of 21 wt% to 25 wt%, based on the uncured resin matrix. Among DEN/TRIF matrix resins, 4,4' -DDS is the preferred curing agent. It is preferably used as a sole curing agent in an amount of 20 to 26 wt%. Other curing agents such as 3,3' -DDS may be included in small amounts (less than 5 wt%), if desired.

In the DEN/TRIF/TETF matrix resin, the curing agent is present in an amount of 15 to 30 weight percent, based on the uncured resin. Preferably, the curing agent is present in an amount of 20 to 30 wt%. 3,3' -DDS is a preferred curing agent. It is preferably used as a separate curing agent in an amount of 24 to 28 weight percent based on the total weight of the uncured resin. Other curing agents such as 4,4' -DDS may be included in small amounts (less than 5 wt%), if desired.

Accelerators may also be included to enhance or accelerate curing. Suitable accelerators are any urone compounds which are commonly used to cure epoxy resins. Specific examples of accelerators that may be used alone or in combination include N, N-dimethyl, N '-3, 4-dichlorophenyl urea (Diuron), N' -3-chlorophenyl urea (Monuron), and preferably N, N- (4-methyl-m-phenylenebis [ N ', N' -dimethylurea ] (e.g., Dyhard UR500 from Degussa).

The uncured resin matrix of the present invention also includes a thermoplastic toughening agent. Any suitable thermoplastic polymer may be used as the toughening agent. Typically, the thermoplastic polymer is added to the resin mixture as particles that are dissolved in the resin mixture by heating prior to adding the curing agent. Once the thermoplastic agent is sufficiently dissolved in the hot matrix resin precursor (i.e., the blend of epoxy resins), the precursor is cooled, the remaining ingredients (curing agent and insoluble thermoplastic particles) are added, and mixed with the cooled resin blend.

Exemplary thermoplastic toughening agents/particles include any of the following thermoplastic materials, alone or in combination: polysulfones, polyethersulfones, polyetherimides, high performance hydrocarbon polymers, elastomers, and segmented elastomers.

A suitable toughening agent is, for example, particulate Polyethersulfone (PES), which is sold under the commercial name Sumikaexcel 5003P, commercially available from Sumitomo Chemicals (New York, NY). An alternative to 5003P is Solvay polyethersulfone 105RP, or a non-hydroxyl terminated grade such as Solvay 1054P, commercially available from Solvay Chemicals (Houston, TX). Dense PES particles may be used as toughening agents. The form of PES is not particularly important as PES is dissolved during the formation of the resin. Dense PES particles may be prepared according to the teachings of us patent 4,945,154, the contents of which are incorporated herein by reference. Dense PES particles are also commercially available from Hexcel Corporation (Dublin, CA) under the commercial name HRI-1. The average particle size of the toughening agent should be less than 100 microns to facilitate and ensure complete dissolution of the PES in the matrix.

In the DEN/TRIF matrix resin, the toughening agent is present in a range of 5 wt% to 15 wt%, based on the total weight of the uncured resin matrix. Preferably, the toughening agent is present in the range of 7 wt% to 12 wt%. More preferably, the toughening agent is present in the range of 8 wt% to 11 wt%.

In the DEN/TRIF/TETF matrix resin, the PES toughening agent is present in the range of 5 wt% to 26 wt%, based on the total weight of the uncured resin. Preferably, the toughening agent is present in the range of 7 wt% to 14 wt%. The preferred amount of PES used to prepare resins having a relatively low minimum viscosity (25-45 poise) is from 7 to 9 weight percent based on the total weight of the uncured resin. The preferred amount of PES used to prepare resins having a relatively high minimum viscosity (55-75 poise) is from 10 to 13 weight percent based on the total weight of the uncured resin.

The matrix resin may also include additional ingredients, such as performance enhancing or modifying agents, provided they do not adversely affect the tack and life of the prepreg or the strength and damage tolerance of the cured composite part. The performance enhancing or modifying agent, for example, may be selected from core shell rubbers, flame retardants, wetting agents, pigments/dyes, UV absorbers, antimicrobial compounds, fillers, conductive particles, and viscosity modifiers.

Exemplary Core Shell Rubber (CSR) particles are composed of: a crosslinked rubbery core, typically a copolymer of butadiene; and a shell composed of styrene, methyl methacrylate, glycidyl methacrylate and/or acrylonitrile. The core-shell particles are typically provided as particles dispersed in an epoxy resin. The particles typically have a size in the range of 50 to 150 nm. Suitable CSR particles are described in detail in U.S. patent publication US2007/0027233A1, the contents of which are incorporated herein by reference. Preferred core-shell particles are MX core-shell particles, available from Kane Ace (Pasadena, Texas). The preferred core-shell particle for inclusion in the DEN/TRIF matrix resin is Kane Ace MX-418. MX-418 was provided as a 25 wt% suspension of core-shell particles in a tetrafunctional epoxy resin. The core-shell particles in MX-418 are polybutadiene (PBd) core-shell particles with an average particle size of 100 nm.

Suitable fillers include, for example, any of the following, alone or in combination: silica, alumina, titania, glass, calcium carbonate and calcium oxide.

Suitable conductive particles include, for example, any of the following conductive particles used alone or in combination: silver, gold, copper, aluminum, nickel, conductive grade carbon, buckminsterfullerene, carbon nanotubes and carbon nanofibers. Metal coated fillers, such as nickel coated carbon particles and silver coated copper particles, may also be used.

Potato Shaped Graphite (PSG) particles are suitable conductive particles. The use of PSG particles in carbon fiber/epoxy composites is described in detail in U.S. patent publication No. US 2015/0179298 a1, the contents of which are incorporated herein by reference. PSG particles are commercially available as SG25/99.95 SC particles from NGS Naturgraplit (Germany) or as GHDR-15-4 particles from Nippon Power Graphite Company (Japan). These commercially available PSG particles have an average particle size of 10-30 microns, with the GHDR-15-4 particles having a vapor deposited coating of carbon on the outer surface of the PSG particles.

The uncured resin matrix may include a small amount (less than 5 wt%, preferably less than 1 wt%) of additional epoxy or non-epoxy thermoset polymer resin. For the DEN/TRIF/TETF matrix resin, the epoxy resin component comprises at least 95 wt% DEN, TRIF and TETF, more preferably at least 99 wt% of the three epoxy resins. For the DEN/TRIF matrix resin, the epoxy resin component comprises at least 95 wt% DEN and TRIF, more preferably at least 99 wt% of both epoxy resins. Suitable additional epoxy resins include difunctional epoxy resins such as bisphenol a type epoxy resins and bisphenol F type epoxy resins. Suitable non-epoxy thermosetting resin materials for use in the present invention include, but are not limited to, phenolic resins, urea-formaldehyde resins, 1,3, 5-triazine-2, 4, 6-triamines (melamines), bismaleimides, vinyl ester resins, benzophenonesAn oxazine resin, a phenolic resin, a polyester, a cyanate ester resin, an epoxy polymer, or any combination thereof. If present, the additional thermosetting resin is preferably selected from the group consisting of epoxy resins, cyanate resins, benzophenonesOxazine resins and phenolic resins.

The uncured resin was prepared according to standard prepreg matrix resin processing. Typically, the hydrocarbon novolac epoxy resin and other epoxy resins are mixed together at room temperature to form a resin mixture to which the thermoplastic toughening agent is added. The mixture is then heated to about 120 ℃ and held for about 1 to 2 hours to dissolve the thermoplastic toughening agent. The mixture is then cooled to about 80 ℃, and the remaining ingredients (if present, the thermoplastic particulate component, the curing agent, and other additives) are mixed into the resin to form the final uncured resin matrix that impregnates the fibrous reinforcement material.

The uncured resin is applied to the fibrous reinforcement material to form an uncured resin matrix according to any known prepreg manufacturing technique. The fibrous reinforcement may be fully or partially impregnated with uncured resin. In an alternative embodiment, the uncured resin may be applied to the fibrous reinforcement material as a separate layer that is closest to and in contact with the fibrous reinforcement material, but does not substantially impregnate the fibrous reinforcement material. This type of partially impregnated prepreg is known as a prepreg and is typically covered on both faces with protective films and rolled up for storage and transport at temperatures that are typically kept well below room temperature to avoid premature curing. The actual resin matrix is not formed until the semi-preg material is further processed. Any other prepreg manufacturing method and storage/transport system may be used if desired.

The fibrous reinforcement of the prepreg may be selected from any glass fibre, carbon fibre or aramid (aramid) fibre. The fibrous reinforcement is preferably carbon fibres. Preferred carbon fibers are in the form of a tow comprising 3,000 to 50,000 carbon filaments (3K to 50K). Commercially available carbon fiber tows containing 6,000 or 24,000 carbon monofilaments (6K or 24K) are preferred.

The uncured matrix resin of the present invention is particularly effective in providing a laminate having high strength properties and damage resistance when the carbon tow comprises 6,000 to 24,000 monofilaments, a tensile strength of 750 to 860ksi, a tensile modulus of 35 to 45Msi, a strain to failure of 1.5 to 2.5%, and a density of 1.6 to 2.0g/cm³And a weight per unit length of 0.2 to 0.6 g/m. 6K and 12K IM7 carbon tows (available from Hexcel Corporation) are preferred. IM 712K fibers had a tensile strength of 820ksi, tensile modulus of 40Msi, strain at failure1.9% and a density of 1.78g/cm³The weight per unit length was 0.45 g/m. The IM 76K fiber had a tensile strength of 800ksi, a tensile modulus of 40Msi, a strain at failure of 1.9%, and a density of 1.78g/cm³The weight per unit length was 0.22 g/m. IM7 fibers and carbon fibers having similar properties are generally considered to be medium modulus carbon fibers. IM8 carbon fiber commercially available from Hexcel Corporation (Dublin, CA) is also a preferred type of medium modulus carbon fiber.

The fiber reinforcement may be in the form of a woven, non-crimped, non-woven, unidirectional, or multiaxial textile structure, such as a quasi-isotropic chopped prepreg used to form sheet molding compounds.

The prepreg may be in the form of a continuous tape, a tow prepreg, a web, or a chopped length (the chopping and slitting operations may be performed at any point after impregnation). The prepreg may be an adhesive or a film lay-up, and may additionally have various forms of implant carrier, both woven and non-woven. The prepreg may be fully or only partially impregnated, for example to assist in the removal of air during curing.

The following exemplary DEN/TRIF/TETF resin formulation can be impregnated into a fibrous support to form a resin matrix according to the present invention (all weight percentages are based on total resin weight):

1)9 to 11 wt% of dicyclopentadiene novolac epoxy resin (C:)556) (ii) a 21 to 23 wt% of triglycidyl-p-aminophenol (MY 0510); 17 to 19 wt% of tetrafunctionalEpoxy resin (MY721), 10 to 13 wt% polyethersulfone (5003P), 8 to 10 wt% polyimide particles (P84HCM), 2 to 4 wt% particles prepared from the condensation product of 3,3 '-dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid (GRI L AMID TR90), and 25 to 28 wt% 3,3' -DDS as curing agent.

2)13 to 16 wt% of dicyclopentadiene novolac epoxy resin (C:)556) 18 to 20 wt% of triglycidyl-P-aminophenol (MY0510), 17 to 19 wt% of tetrafunctional epoxy resin (MY721), 10 to 13 wt% of polyethersulfone (5003P), 8 to 10 wt% of polyimide particles (P84HCM), 2 to 4 wt% of particles prepared from the condensation product of 3,3 '-dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid (GRI L AMID TR90), and 25 to 28 wt% of 3,3' -DDS as curing agent.

3)16 to 18 wt% of dicyclopentadiene novolac epoxy resin (C556) 14 to 16 wt% of triglycidyl-P-aminophenol (MY0510), 17 to 19 wt% of tetrafunctional epoxy resin (MY721), 10 to 13 wt% of polyethersulfone (5003P), 5 to 7 wt% of polyimide particles (P84HCM), 5 to 7 wt% of particles prepared from the condensation product of 3,3 '-dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid (GRI L AMID TR90), and 25 to 28 wt% of 3,3' -DDS as curing agent.

4)13 to 16 wt% of dicyclopentadiene novolac epoxy resin (C:)556) (ii) a 19 to 21 wt% of triglycidyl-p-aminophenol (MY 0510); 18 to 20 wt% of a tetrafunctional epoxy resin (MY 721); 7 to 9 weight percent polyethersulfone (5003P); 2 to 4 wt% of polyimide particles (P84 HCM); 8 to 10 wt.% of a mixture of 3,3' -dimethyl-bis (4-amino)Particles prepared from the condensation product of cyclohexyl) -methane and 1, 10-decanedicarboxylic acid (GRI L AMID TR90) and from 25 to 28% by weight of 3,3' -DDS as curing agent.

5)9 to 11 wt% of dicyclopentadiene novolac epoxy resin (C556) 21 to 23 wt% of triglycidyl-P-aminophenol (MY0510), 19 to 22 wt% of tetrafunctional epoxy resin (MY721), 7 to 9 wt% of polyethersulfone (5003P), 2 to 4 wt% of polyimide particles (P84HCM), 8 to 10 wt% of particles prepared from the condensation product of 3,3 '-dimethyl-bis (4-aminocyclohexyl) -methane and 1, 10-decanedicarboxylic acid (GRI L AMIDTR90), and 26 to 29 wt% of 3,3' -DDS as curing agent.

With respect to the DEN/TRIF matrix resin embodiments of the present invention, a preferred exemplary DEN/TRIF matrix resin comprises 29 to 33 wt% triglycidyl-m-aminophenol (MY0600), 20 to 24 wt% hydrocarbon novolac epoxy resin (TACTIX 556), 7 to 11 wt% polyethersulfone (5003P) as a toughening agent, 2 to 7 wt% crosslinked polyamide 12 particles (ORGASO L2009), 9 to 13 wt% polyamide 11 particles (Rislan PA11) wherein the weight ratio of polyamide 11 particles to crosslinked polyamide 12 particles is 2.5:1.0 to 3.0:1, preferably 2.7:1 to 2.8:1, and 20 to 26 wt% 4,4' -as a curing agent.

Another preferred DEN/TRIF matrix resin comprises: 19 to 23 wt% triglycidyl-m-aminophenol (MY 0600); 14 to 18 weight percent of a hydrocarbon novolac epoxy resin (TACTIX 556); 7 to 11 wt% of polyethersulfone (5003P) as a toughening agent; 9 to 13 wt% polyamide 11 particles (Rislan PA 11); 18-22 wt% core-shell particles (MX-418); and 21 to 26 wt% of 4,4' -DDS as a curing agent.

The prepreg may be molded using any standard technique for forming composite parts. Typically, one or more layers of prepreg are placed in a suitable mold and cured to form the final composite part. The prepregs of the present invention may be fully or partially cured using any suitable temperature, pressure and time conditions known in the art. Typically, the prepreg will be cured in an autoclave at a temperature of 160 ℃ to 190 ℃. The composite material may be cured using a method selected from the group consisting of: microwave radiation, electron beam, gamma radiation, or other suitable thermal or non-thermal radiation.

Composite parts made from the improved prepregs of the present invention may be used in the manufacture of articles such as a variety of primary and secondary aerospace structures (wings, fuselages, bulkheads, etc.), but may also be used in many other high performance composite applications, including automotive, rail and marine applications where high compressive strength, interlaminar fracture toughness and impact damage resistance are required.