DE102013214419A1 - Tooling prepreg with high storage stability and process for its preparation - Google Patents

Abstract

The present invention relates to a tooling prepreg, also referred to below as device prepreg, which has a high storage stability. The invention further relates to a method for producing such a device prepreg and to the use of this device prepreg according to the invention in the production of molded articles.

Description

The present invention relates to a tooling prepreg, also referred to below as device prepreg, which has a high storage stability. The invention further relates to a method for producing such a device prepreg and to the use of this device prepreg according to the invention in the production of molded articles.

Prepregs (preimpregnated materials) are preimpregnated semi-finished products in which fibers and matrix are set in a defined relationship to each other. In principle, both thermoplastic and thermosetting matrix materials can be used. The first prepregs were developed around 1960 at the company Boeing. At that time these were unidirectional fiber-reinforced thermosetting resins for the production of structural components. In the aerospace industry, the use of prepregs quickly became established and still dominates the use of composites today. At the end of the 1980s, continuous fiber reinforced, fully impregnated and consolidated semi-finished products with thermoplastic matrix materials were developed. Due to very high material costs, however, these semi-finished products produced on double belt presses could not initially prevail on the market. With the reduction of manufacturing costs through the use of alternative manufacturing processes, the costs of semi-finished products have been reduced and thermoplastic prepregs are increasingly being used on the market. While a unidirectional fiber reinforcement dominates in the thermoset prepregs, fabric reinforcements are predominantly used in prepregs of thermoplastic matrix. The continuous Duroplastprepregfertigung requires the implementation of constant widths, are common, for example, 30 or 60 cm, which are cut to size during subsequent processing.

The impregnation of the fibers today predominantly uses the so-called solvent impregnation, in which case the resin / hardener mixture is mixed with solvent at room or slightly elevated temperature until the viscosity required for complete impregnation is reached. The fiber scrims are then usually continuously impregnated in an impregnating bath.

It usually follows a drying tower, in which at elevated temperature, the solvent is largely removed and precrosslinking of the resin takes place. The process is relatively complex and problematic because of the residual solvents in the processing from an environmental point of view.

However, the process of melt resin impregnation has become established on the market. Here, the matrix resin is knife-coated in a separate process at elevated temperature on a carrier film and stored. Subsequently, the impregnation of the fibers takes place in a separate device. In this case, the resin film is tempered by heated rollers and thus set the resin viscosity in a favorable range for the impregnation. At the same time, the roller pressure supports the impregnation of the fibers. After passing through a cooling section, the winding and the edge trim take place. The process results in a very good reproducibility of the surface fabric and thus a uniform fiber volume fraction, which is usually set to about 60%.

Prepregs are manufactured in a wide range of thicknesses. For high performance applications are usual 0.125 to 0.250 mm. In this thickness range, the fiber / matrix distribution can be set very evenly. With increasing thickness, the rovings can no longer be stretched uniformly and there is the development of fiber or matrix-rich zones. The mechanical property profile of these prepregs is naturally somewhat less favorable. Due to the higher productivity, the prepregs with a large thickness, over 0.4 mm, but cheaper to manufacture. For thick-walled components under moderate load, as used for example in sports and leisure, thicker prepregs represent an interesting alternative.

Unfortunately, depending on the resin system used, thermoset prepregs have only a limited shelf life. The non-crosslinked matrix material exhibits an autocatalytic behavior and should be stored in a cool, stable manner until stability is maintained. Storage in deep-freeze rooms is quite common. Depending on the conditions so far only a storage of a few hours to a maximum of several weeks is possible.

In the processing prepregs are unfortunately also very limited drapable. Within limits, this can be positively influenced by a temperature control and, concomitantly, a reduction of the resin viscosity.

A thermosetting prepreg is usually obtained by impregnating a semi-finished fiber product with a resin composition made of a resin and a curing agent in the presence of a catalyst, followed by drying and optionally post-curing. The catalyst here has essentially the task of acting as an accelerator.

Epoxy resin systems are predominantly used as resin systems for the prepreg resin composition. Commonly used include bisphenol A epoxies, bisphenol F epoxies, novolak epoxies, BPA novolac epoxies, triglycidyl aminophenols, cycloaliphatic epoxy resins, resole type phenolic resins, cyanate esters and epoxidized cyclopentadienes.

Common hardener systems are amines such as dicyandiamines or aromatic amines. Also conceivable are aliphatic amines such as alkyleneamines. These may be mentioned as representatives such as monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamines, N- (2-aminoethyl) piperazine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylenediamine, 4-aminoethylenetetraamine, tetraethylenepentamine, aminoethylpiperazinoethylenediamines and piperazinoethylenetriamine.

Common catalysts which may be mentioned in particular are Lewis acid-amine complexes, such as BF ₃ -monoethylamine, BF ₃ -triethanolamine, BF ₃ -piperidine, BF ₃ -2-methylimodazole, amines, such as imidazole, 1-methylimidazole, 2-methylimidazole, 2-ethyl 4-methylimidazole, N, N-dimethylbenzylamine, other tertiary amines, tertiary amine hydrochloric acids such as imidazole or morpholine p-toluenesulfonic acid salts, imidazole or benzyldimethylamine salicylic acid salts, dicyanamide, 1,1-dimethyl-3-phenylurea or other substituted ureas such as monuron , Diuron or phenuron, substituted imidazoles, trifluoromethanesulfonic acid salts, carbamides such as toluene-2,4-bis (N, N-dimethylcarbamide), guanidines such as di-ortho-tolylguanidine, diphenylguanidine, tetramethylguanidine, OH-containing compounds such as bisphenol-A, -F, -S, catechol, dihydroxynaphthalene, hydroquinones, tetrabromobisphenol-A and organophosphonium halides.

In DE 2033 626 For example, a method of making a prepreg system is disclosed. The method comprises reacting a preimpregnated fiber which is contacted with a solution of curable polyadduct and a curing agent in a solvent. The curable polyadduct used is triglycidyl isocyanurate, which is reacted with aromatic or heterocyclic polyamines containing at least two primary amino groups under heat.

In US 5,614,126 discloses a process for the solvent-free production of a storage-stable prepreg, wherein a solid epoxy resin is used, which is prepared from bisphenol A, bisphenol F or novolak epoxies by ionic polymerization.

In US 4,874,661 are disclosed prepregs prepared from epoxy resins such as bis (N, N-diglycidyl-4-aminophenyl) methanes and curing agents such as diphenyldiaminosulfoxide. In addition, small amounts of trivalent chromium and inorganic hair fibers are added. The decomposition temperature of a prepreg produced in this way is about 300 ° C, the final glass transition temperature at 195 ° C.

In JP 10045925 A2 discloses a process for producing a prepreg which is crosslinked at a low temperature and very stable at a high temperature. The epoxy resin used is bisphenol A, phenolic novolak or tetraglycidyldiaminodiphenylmethane. The curing agent is an aromatic amine such as diaminodiphenylsulfone, the catalyst is an imidazole catalyst.

In general, prepregs for the construction of certain devices, so-called device prepregs, so far used only for implementations of geometrically simple components and moldings. Due to the exact fiber orientation, it is relatively easy to set the highest strength and stiffness values here. Thus, device prepregs would be predestined for the construction of thin-walled shell structures and complex shaped bodies.

Limiting, however, remains the problem of limited shelf life. Thus, it is disadvantageous if the prepregs can no longer be successfully processed after a short lifetime at room temperature. In particular, for the application in complex moldings, which often have to be built up over a longer period of time or for use in large moldings device prepregs are generally still hardly used because they spoil already during the molding process and then are no longer processable.

The object of the present invention is therefore to provide a method for producing a device prepreg which is simple to carry out and which makes available a device prepreg which is distinguished by an excellent and long and unproblematic storage stability at room temperature and even after several Weeks can be further processed into a complex shaped body.

• i) Vorlegen eines Epoxidharzes welches ausgewählt ist aus der Gruppe bestehend aus Tetraglycidylmethylendiaminharz (TGMDA), Bisphenol-A-Epoxid, Bisphenol-F-Epoxid, Novolack-Epoxid, BPA-Novolack-Epoxid, Triglycidylaminophenol, cycloaliphatischem Epoxidharz, Phenolharz des Resoltyps, Cyanatester und epoxidiertem Cyclopentadien;
• ii) Zudosieren eines Härtungsmittels welches ausgewählt ist aus der Gruppe bestehend aus Dicyandiamin, aromatischen Aminen wie Diphenyldiaminosulfoxid (DDS), aliphatischen Aminen wie Alkylenaminen ausgewählt aus Monoethanolamin, Ethylendiamin, N-(2-Aminoethyl)ethanolamin, Diethylentriamine, N-(2-Aminoethyl)piperazin, Triethylentetraamine, Tetraethylenpentamin, Pentaethylenhexamin, Diaminoethylpiperazin, Piperazinoethylendiamin, 4-Aminoethylentetraamin, Tetraethylenpentamin, Aminoethylpiperazinoethylendiamine und Piperazinoethylentriamin;
• iii) Mischen des resultierenden Gemisches bis sich eine homogene Suspension ergibt;
• iv) Einwiegen und Zugeben eines Katalysators zu der Suspension aus iii) unter Erhalt einer Mehrkomponentenmischung;
• v) Mischen der resultierenden Mehrkomponentenmischung;
• vi) Imprägnieren eines Faserhalbzeugs mit der Mehrkomponentenmischung aus v) unter Erhalt des Vorrichtungsprepregs,

dadurch gekennzeichnet, dass der Katalysator in Schritt iv) Bortrifluorid-Etherat (BF₃·OEt₂) ist.This object has been achieved by a method for producing a device prepreg comprising at least the following steps

• i) presenting an epoxy resin selected from the group consisting of tetraglycidylmethylenediamine resin (TGMDA), bisphenol A epoxy, bisphenol F epoxy, novolak epoxy, BPA novolak epoxy, triglycidylaminophenol, cycloaliphatic epoxy resin, resol type phenolic resin, cyanate ester and epoxidized cyclopentadiene;
• ii) adding a curing agent selected from the group consisting of dicyandiamine, aromatic amines such as diphenyldiaminosulfoxide (DDS), aliphatic amines such as alkyleneamines selected from monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamines, N- (2-aminoethyl ) piperazine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylenediamine, 4-aminoethylenetetraamine, tetraethylenepentamine, aminoethylpiperazinoethylenediamines and piperazinoethylenetriamine;
• iii) mixing the resulting mixture until a homogeneous suspension results;
• iv) weighing and adding a catalyst to the suspension of iii) to obtain a multi-component mixture;
• v) mixing the resulting multicomponent mixture;
• vi) impregnating a semifinished fiber product with the multicomponent mixture from v) to obtain the device prepreg,

characterized in that the catalyst in step iv) is boron trifluoride etherate (BF ₃ .OEt ₂ ).

When presenting the epoxy resin in step i) this is preferably slightly heated. Preferably, it is at a temperature of 40 to 60 ° C, more preferably at 50 ° C before.

During the metered addition of the diphenyldiaminosulfoxide (DDS) in step ii), this is preferably not tempered, but is present at room temperature, more preferably at a temperature of 20-25 ° C.

In order to achieve a homogeneous suspension in step iii), stirring is preferably carried out for 2 to 30 minutes at 10-2000 rpm. For this purpose, the use of a wing mixer is particularly suitable.

Weighing and adding boron trifluoride etherate (BF ₃ .OEt ₂ ) to the suspension of iii) to obtain a multicomponent mixture is preferably carried out at room temperature in step iv), but may also be carried out at a temperature above or below room temperature, for example 10-15 ° C or at 25-30 ° C take place.

For the mixing of the resulting multicomponent mixture in step v), a mixing speed of about 10-2000 rpm is again suitable, as well as the use of a blade mixer.

The impregnation step in step vi) can be carried out in any manner known to the person skilled in the art. For example, dipping method, spraying method, melting method and Auswalzverfahren come into question.

The impregnation step may be followed by a first thermal treatment which may result in the partial crosslinking of the resin. This can be carried out at temperatures between 100-200 ° C, preferably 120 ° C-150 ° C by any method known in the art.

Tetraglycidylmethylenediamine resin (TGMDA) and diphenyldiaminosulfoxide (DDS) are preferably used as the epoxy resin.

The preferred or obligatory components tetraglycidylmethylenediamine resin (TGMDA), diphenyldiaminosulfoxide (DDS) and boron trifluoride etherate (BF ₃ .OEt ₂ ) are known by the following structural formulas:

• a) 50–80 Mol-% eines Epoxidharzes, vorzugsweise Tetraglycidylmethylendiaminharz (TGMDA)
• b) 20–49,9 Mol-% eines Härtungsmittels, vorzugsweise Diphenyldiaminosulfoxid (DDS) und
• c) 0,1–10 Mol-% Bortrifluorid-Etherat (BF₃·OEt₂).

In the process according to the invention, the components used are preferably used in the following proportions and reacted with one another:

• a) 50-80 mol% of an epoxy resin, preferably tetraglycidylmethylenediamine resin (TGMDA)
• b) 20-49.9 mol% of a curing agent, preferably Diphenyldiaminosulfoxid (DDS) and
• c) 0.1-10 mol% boron trifluoride etherate (BF ₃ .OEt ₂ ).

• a) 56–75 Mol-% Tetraglycidylmethylendiaminharz (TGMDA)
• b) 25–45,9 Mol-% Diphenyldiaminosulfoxid (DDS) und
• c) 0,1–5 Mol-% Bortrifluorid-Etherat (BF₃·OEt₂).

More preferably, the following proportions of the individual components are used:

• a) 56-75 mol% tetraglycidylmethylenediamine resin (TGMDA)
• b) 25-45.9 mol% diphenyldiaminosulfoxide (DDS) and
• c) 0.1-5 mol% boron trifluoride etherate (BF ₃ .OEt ₂ ).

The semifinished fiber products used in step vi) come from individual fiber filaments, which are otherwise difficult to handle. For this purpose, dry fibers are combined into semi-finished products, so-called semi-finished fiber products. The manufacturing processes originate in many parts of textile technology such as weaving, braiding or embroidery.

"Tissues" are created by the interweaving of continuous fibers, such as rovings. The interweaving of fibers inevitably involves an ondulation of the fibers. The ondulation causes in particular a reduction of the fiber-parallel compressive strength. Therefore, it is preferable to use scrims rather than tissue for mechanically high-quality fiber-plastic composites.

In a "clutch", the fibers are ideally parallel and stretched. Only continuous fibers are used. Scrims are held together by a paper, binder or thread stitching. The binders used are preferably powder connectors.

If the fibers are not oriented exclusively in the plane, it is called "multiaxial". Most of the additional fibers are oriented perpendicular to the laminate plane to improve the delamination and impact performance.

If individual rovings in the plane are not only stretched, but lie on arbitrary tracks, so you use "embroidery". The rovings are embroidered on a carrier material (eg a fleece) and fixed in this way. Embroideries are often used in the area of load introduction, as often a complex fiber orientation is desired here. Embroideries are used as preforms for the RTM process (Resin Transfer Molding).

In the "braiding process", mainly rovings are braided from rovings, which are used to produce pipes, containers or generally hollow components.

If components with quasi-isotropic properties are to be produced, "fiber mats" can be used. The mats are usually made of short and long fibers, which are loosely connected by a binder. Through the use of short and long fibers, the mechanical properties of components made of mats are inferior to those of fabrics.

"Nonwovens" are made by needling long fibers. They serve as a thin layer applied to the surface protection or the improvement of the surface ripple. The mechanical properties are quasi-isotropic and inferior to those of tissues.

"Fine cuts" are mainly used as a filler. They can increase the mechanical properties of pure resin areas and possibly lower the density.

"Spacer fabrics" serve to produce sandwich structures.

Any of the semifinished fiber molds defined above may be used for the present invention. However, preference is given to using fabrics, scrims or nonwovens.

The semi-finished fiber used in step vi) can basically consist of any semi-finished fiber material known to the person skilled in the art. These include plastic fibers such as polyacrylate fibers, polyacrylonitrile, glass fibers, viscose fibers, silk fibers, carbon, graphite or carbon fibers and other fibers.

However, the semi-finished fiber product in step vi) preferably represents a carbon fiber or a carbon fiber semi-finished product.

By using a carbon fiber and / or carbon fiber based semi-finished fiber product, a prepreg of comparatively low weight and high mechanical and thermal resistance can be produced.

• a) 50–80 Mol-% eines Epoxidharzes
• b) 20–49,9 Mol-% eines Härtungsmittels und
• c) 0,1–10 Mol-% Bortrifluorid-Etherat (BF₃·OEt₂).

The present invention also relates to a device prepreg which contains a resin composition which is produced from at least the following educts:

• a) 50-80 mol% of an epoxy resin
• b) 20-49.9 mol% of a curing agent and
• c) 0.1-10 mol% boron trifluoride etherate (BF ₃ .OEt ₂ ).

In a particular embodiment of the invention, the epoxy resin is selected from the group consisting of tetraglycidylmethylenediamine resin (TGMDA), bisphenol A epoxide, bisphenol F epoxide, novolak epoxy, BPA novolak epoxide, triglycidylaminophenol, cycloaliphatic epoxy resin, resol type phenolic resin , Cyanate ester and epoxidized cyclopentadiene.

Particularly preferred is the use of the epoxy resin tetraglycidylmethylenediamine resin (TGMDA).

In a further particular embodiment of the invention, the curing agent is selected from the group consisting of dicyandiamine, aromatic amines such as diphenyldiaminosulfoxide (DDS), aliphatic amines such as alkyleneamines, in particular monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamine, N- (2-aminoethyl) piperazine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylenediamine, 4-aminoethylenetetraamine, tetraethylenepentamine, aminoethylpiperazinoethylenediamines and piperazinoethylenetriamine.

Particularly preferred is the use of the curing agent diphenyldiaminosulfoxide (DDS).

• a) 56–75 Mol-% Tetraglycidylmethylendiaminharz (TGMDA)
• b) 25–45,9 Mol-% Diphenyldiaminosulfoxid (DDS) und
• c) 0,1–5 Mol-% Bortrifluorid-Etherat (BF₃·OEt₂).

In a further embodiment of the invention, the device prepreg is made of a resin composition made of at least the following educts:

• a) 56-75 mol% tetraglycidylmethylenediamine resin (TGMDA)
• b) 25-45.9 mol% diphenyldiaminosulfoxide (DDS) and
• c) 0.1-5 mol% boron trifluoride etherate (BF ₃ .OEt ₂ ).

The device prepreg according to the invention is characterized in that the resin composition has a high final glass transition temperature (T _g ) between 200 ° C and 220 ° C. As a result, the device prepreg according to the invention exhibits excellent thermal and mechanical stability.

Surprisingly, it has been found that the use according to the invention of the boron trifluoride etherate (BF ₃ .OEt ₂ ) has the result that the device prepreg produced therefrom, in contrast to device prepregs used in the production of other catalysts, has a particularly long storage and processing stability.

This could be explained by the fact that the diethyl ether contained in the boron trifluoride etherate (BF ₃ .OEt ₂ ) complex evaporates completely during the process, thus obtaining a stable and chemically unalterable device prepreg. Surprisingly, this effect is not found in other BF ₃ complexes. In addition, it has also been found that the evaporation of diethyl ether takes place in such amounts that no additional safety measures are necessary in carrying out the process. Consequently, the process is also easy to implement and the products offer the highest quality. The process is highly reproducible.

The present invention also relates to a device prepreg made by the method of the invention.

Due to the long shelf life of Vorrichtungsprepreg invention are now also other applications in mold design conceivable.

Therefore, the present invention also relates to the use of the device prepreg according to the invention for producing a shaped article.

Particular preference is given to producing moldings which find use as components in industry. However, it is also conceivable high-precision parts such as robot arms, or the application in aerospace, for example, as the wing or fuselage part of a missile. In addition, the use of the device prepregs according to the invention as moldings in the automotive industry, for example a car body or a drive or chassis, is particularly preferred. In principle, any molded article produced from the device prepreg according to the invention is suitable.

Since the shelf life of the device prepregs could be extended to weeks in this invention, the device prepregs of the present invention can now basically also be applied to such mold making requiring a longer period of time or where large dimensions are to be produced in simpler process management.

Examples

The present invention is explained in more detail below with reference to examples:

1. Preparation of the device prepreg

60 mol% of tetraglycidylmethylenediamine resin (TGMDA) were introduced and slowly heated to a temperature of 50.degree. 37 mol% of the tempered to room temperature Diphenyldiaminosulfoxids (DDS) were added slowly to this heated material. The resulting mixture was processed for about 10 minutes by means of a blade mixer at about 1200 rev / min to a homogeneous mixture. After the mixing process, the homogeneous mixture was cooled again to room temperature and 3 mol% boron trifluoride etherate (BF ₃ · OEt ₂ ) were added dropwise slowly and with continuous stirring. After the end of the addition, homogenization was continued for about 20 minutes using a wing mixer at about 1800 U / min until the resulting homogeneous impregnating agent could be obtained. Subsequently, a carbon fiber semi-finished product, configured as a carbon fiber fabric, was brought into contact with the multicomponent resin mixture by means of the impregnating agent present as a multicomponent resin mixture by knife coating onto the support material and insertion of the carbon fiber scrim provided with a powder connector and thus uniformly impregnated. This was followed by a final drying at 120 ° C to obtain a layer of a storable and storable device prepreg according to the invention.

2. Production of the molding

First, an original aluminum mold was pretreated by means of a gelcoat or release agent. The gelcoat here consisted of thickened with silica, fiberless synthetic resin (usually unsaturated polyester).

For the molded article production, the aluminum original form was first molded with the previously prepared prepreg layers. After the first two prepreg layers were designed, evacuation (p <0.1 bar for 60 minutes) was first evacuated to obtain a good surface impression. After every 3rd to 5th layer, the mold was evacuated again so that possible air pockets could be removed.

As prepreg layers it was basically possible to use device prepregs based on carbon fiber fabric, carbon fiber fabric (unidirectional and multiaxial fabric) and carbon fiber nonwoven fabric. In the present case, a carbon fiber fabric prepreg with various carbon fiber fabrics with 95-640 g / m ² fiber surface weight (95 g / m ² canvas carbon fiber fabric) was used, which was impregnated with 40% -50% resin content. The resin system included: TGMDA 59.8 mol% DDS 35.7 mol% BF ₃ OEt ₂ 4.5 mol%

The molded article was produced via a layer structure with 5-10 layers of 200 g / m ² material and 10-400 layers with 420 g / m ² material, wherein the individual layers in 0 / + 45 / -45 / 90 ° angles as layers were laid to each other. After the first two layers was first compacted for 1 hour (0.1 bar). Subsequently, after every 5th layer, the mixture was compacted for about an hour at about 0.1 bar. The structure of the shaped body takes place over 3 days without any hardening or aging of the material was observed. To cure the finished structure, the following cycle was finally used:
25-120 ° C / 1 ° C / min // 6h isothermal // 120 - <60 ° C / 1 ° C / min under 0.1 bar vacuum.

The subsequent postcuring was carried out at 195.degree. A cure cycle of 0.5 ° C / min to 195 ° C was used with an isothermal hold time of 60 minutes at 195 ° C. After cooling, the finished shaped body could be obtained.

3. Viscosity comparison

The tooling resin system according to the invention was compared with a Toolingharzsystem which was prepared by means of another catalyst, in terms of its viscosity.

The tooling resin system (1) according to the invention corresponded in its composition to that of Example 1, ie:
60 mole% tetraglycidylmethylenediamine resin (TGMDA)
37 mol% diphenyldiaminosulfoxide (DDS)
3 mol% boron trifluoride etherate (BF ₃ · OEt ₂ )

The comparative tooling resin system (2) had the following composition:
60 mole% tetraglycidylmethylenediamine resin (TGMDA)
37 mol% diphenyldiaminosulfoxide (DDS)
3 mol% 2-ethyl-4-methylimodazole Table 1: Viscosity comparison Epoxy tooling system Viscosity immediately after preparation at 25 ° C [Pas] Viscosity after 48 h at 25 ° C [Pas] (1) 210 240 (2) 5 40000

As shown in Table 1, tooling resin systems which do not use boron trifluoride etherate (BF ₃ .OEt ₂ ) as a catalyst, but another, low volatility catalyst component, initially have a very low viscosity, but extremely high viscosity over a short period of time becomes solid and unusable for further processing. Thus, it could be shown that the use of boron trifluoride etherate (BF ₃ · OEt ₂ ) as catalyst offers extreme advantages in the production of device prepregs, since these can still be processed without problems even after weeks at room temperature.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2033626 [0013]
• US 5614126 [0014]
• US 4874661 [0015]
• JP 10045925 A2 [0016]

Claims (15)

Process for the preparation of a device prepreg comprising at least the following steps: i) providing an epoxy resin which is selected from the group consisting of tetraglycidylmethylenediamine resin (TGMDA), bisphenol A epoxide, bisphenol F epoxide, novolak epoxide, BPA novolak epoxide, Triglycidylaminophenol, cycloaliphatic epoxy resin, resol type phenol resin, cyanate ester and epoxidized cyclopentadiene; ii) adding a curing agent selected from the group consisting of dicyandiamine, aromatic amines such as diphenyldiaminosulfoxide (DDS), aliphatic amines such as alkyleneamines selected from monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamines, N- (2-aminoethyl ) piperazine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylenediamine, 4-aminoethylenetetraamine, tetraethylenepentamine, aminoethylpiperazinoethylenediamines and piperazinoethylenetriamine; iii) Mixing the resulting mixture to give a homogeneous suspension iv) Weighing and adding a catalyst to the suspension of iii) to obtain a multicomponent mixture v) Mixing the resulting multicomponent mixture vi) Impregnating a semifinished fiber product with the multicomponent mixture of v) to obtain the device prepreg , characterized in that the catalyst in step iv) boron trifluoride etherate (BF ₃ · OEt ₂ ) is. A method according to claim 1, characterized in that in the manufacturing process a) 50-80 mol% of the epoxy resin b) 20-49.9 mol% of the curing agent and c) 0.1-10 mol% of the boron trifluoride etherate ( BF ₃ · OEt ₂ ) catalyst are reacted with each other. A method according to claim 1 or 2, characterized in that is used as the epoxy resin Tetraglycidylmethylendiaminharz (TGMDA) and as a curing agent Diphenyldiaminosulfoxid (DDS). Process according to claim 3, characterized in that in the production process a) 56-75 mol% of tetraglycidylmethylenediamine resin (TGMDA) b) 25-45.9 mol% of diphenyldiaminosulfoxide (DDS) and c) 0.1-5 mol% of boron trifluoride -Etherat (BF ₃ · OEt ₂ ) are reacted with each other. Method according to one of claims 1 to 3, characterized in that the semi-finished fiber product in step vi) is a carbon fiber semi-finished product. Device prepreg containing a resin composition prepared from at least the following educts: a) 50-80 mol% of an epoxy resin b) 20-49.9 mol% of a curing agent c) 0.1-10 mol% of boron trifluoride etherate (BF ₃ · OEt ₂ ). Device prepreg according to claim 6, characterized in that the epoxy resin is selected from the group consisting of tetraglycidylmethylenediamine resin (TGMDA), bisphenol A epoxides, bisphenol F epoxides, novolak epoxies, BPA novolak epoxies, triglycidylaminophenols, cycloaliphatic epoxy resins, Resole type phenolic resins, cyanate esters and epoxidized cyclopentadienes. Device prepreg according to claim 6, characterized in that the curing agent is selected from dicyandiamine, aromatic amines such as diphenyldiaminosulfoxide (DDS), aliphatic amines such as alkyleneamines selected from monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamines, N- (2 Aminoethyl) piperazine, triethylenetetraamine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylenediamine, 4-aminoethylenetetraamine, tetraethylenepentamine, aminoethylpiperazinoethylenediamine and piperazinoethylenetriamine. Vorregementsprepreg according to one of claims 6 to 8, characterized in that is used as the epoxy resin Tetraglycidylmethylendiaminharz (TGMDA) and as a curing agent Diphenyldiaminosulfoxid (DDS). Device prepreg containing a resin composition prepared from at least the following educts: a) 50-80 mol% tetraglycidylmethylenediamine resin (TGMDA) b) 20-49.9 mol% diphenyldiaminosulfoxide (DDS) and c) 0.1-10 mol% Boron trifluoride etherate (BF ₃ · OEt ₂ ). Device prepreg according to claim 10, characterized in that the resin composition is prepared from at least the following educts a) 56-75 mol% tetraglycidylmethylenediamine resin (TGMDA) b) 25-45.9 mol% diphenyldiaminosulfoxide (DDS) and c) 0.1- 5 mol% boron trifluoride etherate (BF ₃ .OEt ₂ ). Device prepreg according to claim 10 or 11, characterized in that the resin composition has a final glass transition temperature (T _g ) between 200 ° C and 220 ° C. A device prepreg produced by a process according to any one of claims 1 to 5. Use of a device prepreg according to one of claims 6 to 9 or 10 to 12 for the production of a shaped article. Use of a device prepreg according to claim 14, characterized in that the shaped body represents a component for industry, a robot arm, a wing or fuselage part of a missile, a car component or a drive or chassis.