DE102006041037A1 - Flameproof, low temperature curing, cyanate based resins with improved properties - Google Patents

Abstract

Prepolymer, obtained by using at least a di- or poly- functional organic cyanate, at least a di- or poly- functional aromatic alcohol, at least a di- or poly- functional aliphatic compounds and optionally at least a filler material, where: the aliphatic residue contains at least a fluorine substituted alcohol, the molar ratio of the cyanato group to hydroxy group in the initial material is 95:5-70:30; and the resin exists in a cross-linking degree, is new. Prepolymer obtained by using at least a di- or poly- functional organic cyanate, at least a di- or poly- functional aromatic alcohol, at least a di- or poly- functional aliphatic compounds and optionally at least a filler material, where: the aliphatic residue contains at least a fluorine substituted alcohol, the molar ratio of the cynato group to hydroxy group in the initial material is 95:5-70:30; the resin exists in a cross-linking degree, which is less than the gel point; and the prepolymer is not produced from the dicyanate derivative of bisphenol A, bisphenol A or its brominated derivative, 4,4'-thiodiphenol with out any filler material, aliphatic dicyanate and diol, is new. An independent claim is included for molded or layered body, obtained by hardening the prepolymer at increased pressure and temperature.

Description

The The invention relates to resins (prepolymers) of di- or polycyanates and multifunctional alcohols, which may additionally be suitable rheological Modifiers and / or other fillers may contain.

For the production of molded parts, e.g. from casting resins, coated fabrics, Adhesives, adhesion promoters and other things often require lightweight plastic materials, after curing good surface properties have, which are fire retardant or act and the same time can be very stable mechanically. The requirements for the fire behavior often include a low flammability, a low heat release rate, a low smoke density and low toxicity of the formed Fumes.

For this Purposes can be liquid or use viscous resins, which are with the help of heat and / or Post-cure printing. Because of the above high fire requirements come as resins for such purposes primarily phenolic resins in question. However, phenolic resins can do not provide the required mechanical properties; for applications, in which e.g. Impact loads are often theirs high brittleness problematic. Furthermore become phenol resins over a polycondensation reaction shown in the light and with it volatile Components are released. Go on curing of such resin these in the gas state over. This can cause the surface quality of such materials produced moldings is unsatisfactory, e.g. by blistering.

moreover exist in the manufacture of resins for various applications Special requirements. An example is the stickiness behavior (the so-called tack, or the reactivability of the tack), possibly through Modifications (formulation) of the resin must be guaranteed. One such stickiness behavior is e.g. for adhesives, casting resins, Binder for Laminates or adhesion promoters needed. Blistering can lead to defects in appropriate applications in the adhesive surfaces to lead.

Around To formulate resins that produce moldings with very good surfaces The use of addition resins seems more promising than that of condensation resins, since no gases are released during curing become. Addition resins with good mechanical properties are epoxy resins and cyanate resins. However, today, commercially available epoxy resins are for some Not sufficiently flame retardant because of an increased (inadmissible) fire load, specifically have flue gas density. The electronics are indeed halogenated epoxy resins with high flame retardancy, the Use of halogens leads however, in case of fire, the formation of highly toxic and highly corrosive Gases, which precludes use.

cyanate By contrast, their network structure (as a result of the high nitrogen content) an intrinsic flame retardancy on. They combine a low heat release rate with a low smoke density and a low proportion of toxic Gases in case of fire.

Of the Influence of multifunctional phenols on the cross-linking of cyanate resins was earlier on a model system of bisphenol A dicyanate and bisphenol A or brominated bisphenol A under theoretical, especially kinetic Examined aspects, see, e.g. M. Bauer et al., Makromol. Chem., Macromol. Symp. 45, 97-103 (1991); M. Bauer, Pure and Modified Polycynurates-Polymers with Great Future as Adhesives, Casting Resins, and Binders for Laminates, Acta polymer. 43, 299-302 (1992). Resins of bisphenol A dicyanate and bisphenol A or its Brominated derivatives are therefore not the subject of this invention.

There are some suggestions in the literature for the use of cyanate resins. Thus, in the Japanese abstract with the publication no. 2002-194212 A discloses a curable resin composition for laminates or prepregs therefor comprising a cyanate ester, a monofunctional phenol component, a polyphenylene ether resin, a flame retardant which can not react with the cyanate ester, and a metal-containing reaction catalyst. The heat-resistant moldable resin is used to make a prepreg and a laminate. The Japanese abstract with the publication no. 2002-146185 proposes a similar resin; however, instead of the polyphenylene ether resin, a polyethylene resin is used for this purpose. According to the Japanese abstract with the publication no. 02-302446, there is provided a prepreg and a circuit board made therefrom, wherein the components for the impregnating resin are a polyaromatic cyanate, a polyhydric phenol, a polyaromatic cyanate phenol, a catalyst and, if necessary, a flame retardant. Also provided for a printed circuit is the resin composition disclosed in U.S.P. EP 0889096 A2 and a modified cyanate ester, a monofunctional phenol component, a Polyphenylenetherharz and a flame retardant is produced.

In the EP 0295375 A2 The proposal is to provide prepregs with a peelable, silicone-coated film to ensure a long-lasting tack. The resin of the prepregs consists of a cyanate-functionalized base containing additional ingredients such as epoxy or maleimide resins.

in the Japanese Abstract 03243634 A discloses a resin consisting of 2-30% by weight the reaction product of neopentyiglycol and terephthalic acid chloride, So an oligoester, with an average molecular weight from 200-2000 and hydroxy groups at both ends, as well as 98-70% by weight of a resin a cyanate ester component and a bismaleimide component. With this resin are corresponding organic or inorganic Impregnated fibers.

• – eine Verarbeitbarkeit/Härtbarkeit (mit oder ohne Druck) im Bereich zwischen ca. 100°C und 200°C über einen Zeitraum von wenigen Minuten,
• – eine gute Lagerstabilität, und
• – eine geringe Sprödigkeit sowie eine hohe Brandfestigkeit der aus den Harzen hergestellten Materialien mit geringer Wärmefreisetzungsrate, niedriger Rauchgasdichte sowie geringer Toxizität der gebildeten Brandgase.

The object of the present invention is to provide resins (prepolymers) which at the same time should have the following properties:

• A workability / hardenability (with or without pressure) in the range between about 100 ° C and 200 ° C over a period of a few minutes,
• - good storage stability, and
• - Low brittleness and high fire resistance of the materials produced from the resins with low heat release rate, low smoke density and low toxicity of the combustion gases formed.

In specific embodiments of the invention are intended to continue the resins a permanent or recoverable with the aid of a solvent Have stickiness to their use as adhesives, adhesion promoters or adhesives to ensure the like.

The solution the task is difficult. For especially flame-retardant cyanate resins based on phenolic novolacs, e.g. PT resins the Fa. Lonza, have to complete Curing very high glass transition temperatures. To complete a conversion of cyanate groups Therefore, it is necessary to apply high curing temperatures. It is also possible Harden at lower temperatures, because the reaction can be e.g. by using conventional Catalysts such as e.g. Metal acetylacetonate complexes be accelerated. However, by the use of such Catalysts did not lower the maximum glass transition temperature, and only the first phase of the curing reaction is accelerated; at curing far below the curing temperature, the for the maximum conversion required to OCN groups freezes Reaction at a given OCN conversion (that of the cure temperature or their distance from the maximum glass transition temperature (i.e. Glass transition temperature at maximum OCN conversion) is a. Below a certain turnover, cyanate networks become brittle extraordinary.

Therefore could looking for other catalysts that are network modifiers at the same time, which widen the network and at the same time the crosslinking reaction the cyanate resins (trimerization) catalyze. Through a network expansion would the Glass temperature lowered, so that curing temperatures are selected can, the lower than the for pure cyanate ester resins needed lie, and thus can be avoided that the above described embrittlement due to low turnover occurs at OCN groups.

These However, searching is problematic. The one described in the literature Addition of monofunctional phenols, for example, does not appear promising. Monofunctional phenols as used in the prior art are incorporated into the polymer during the reaction. The underlying Mechanism is very complex. The inventors of the present application namely have found that the number of OH groups despite the incorporation of the Phenols remains constant. The reason is the following: For every one responded OH group is released at another location an OH group. The effect of multifunctional Phenols, therefore, is that of a trifunctional crosslinker a difunctional link is because the OH group forms a network chain end. This will monophenols excessively reduced the network density. They are suitable therefore not for the purposes of the present invention because they are the glass transition temperatures clearly over every desirable one Measure beyond minimize and you in the resin as well an undesirable high sol content. Another disadvantage is that Components with relatively high volatility remain in the resin, the later Outgassing, which in turn must be prevented because, as already described above, As a result, for example, insufficient surface qualities (blistering of products made therefrom). Besides, they are the starting components volatile, what processing (and possibly also hazardous) problems with it brings.

by virtue of The presence of hydroxy groups would also be expected that the reaction, at least over longer periods of time, like them at a longer Storage may occur, not as required before reaching the gel point comes to a standstill, but runs to a degree of crosslinking, the more than the gel point and thus the processability (the homogeneous fusibility) the resins lies.

One good storage stability However, it is absolutely necessary because resins like those of the present Invention and included after their manufacture, and either as unshaped mass or already in the external Final form transferred, often over one longer Period must be stored, before using heat and / or pressure in the final Curing be transferred.

Around To ensure good processing of the resins, they can if necessary in addition contain rheological modifiers. Such modifiers or other fillers can also for improving adhesion, hardness, toughness, impact strength, hydrophilicity / hydrophobicity or the like. These modifiers the cyanate resins are allowed not at the same time the very good fire properties (low Heat Release Rate low smoke density, low content of toxic gases in case of fire). Epoxides as co-monomers are for Example not suitable because by the modification of cyanate resins Like PT resins with epoxies both the heat release rate and the smoke density is significantly increased.

Especially the flow properties the resins can optionally adjusted thereby, that the heat curing (e.g. in a press) leads to excellent surfaces of the products.

Surprisingly can according to the invention a resin or prepolymer, all of the above conditions Fulfills. This resin or prepolymer is made using at least a multifunctional cyanate and at least one multivalent Alcohol as defined in claim 1 in proportions which include molar ratio the OCN groups to OH groups in the starting materials for the preparation of the prepolymer or resin between 95: 5 and 70:30, using a resin from the Dicyanate derivative of bisphenol A in which the hydroxy groups replaced by cyanate groups, and bisphenol A or a brominated one Derivative of bisphenol A should be excluded from the scope. Locked out should also be such resins whose hydroxy and cyanate starting materials exclusively difunctional and aliphatic in nature.

Under "prepolymer", "resin" and "prepolymerized Resin "is according to the invention equally one to below the gel point crosslinked addition polymer from the or understood using the respective said starting substances become.

The Cyanate resins should preferably be free of epoxy resin ingredients.

The present invention thus provides with multifunctional, predominantly aromatic alcohols modified cyanate resins that are available as casting resins, Adhesives, adhesion promoters or the like are suitable and at very moderate temperatures (between about 100 ° C and 200 ° C) if necessary, cure under pressure in the minute range (about 1-20 min).

Possibly. Existing modifications of the cyanate resin (i.e., the formulations) do not affect the high flame retardancy of the resins, or only slightly, i. e. the low heat release rate and low smoke density is preserved. The proportion of toxic gases will not be increased.

As a surprise can be highlighted that latency is achieved, although with the aromatic alcohols, as defined above, compounds used whose catalytic effect is a further reaction of the resins could be expected. This latency allows the production, transport and storage of the resins in the usual today Periods.

In special embodiments, the resin is at least one filler added, obtained by means of which excellent surfaces and / or a good connection to a substrate can be achieved. Furthermore can be adjusted according to need a high tack or this Tack by spraying with a suitable solvent, e.g. Isopropanol, can be reactivated even after long storage times, as is common for applications required which is a good attachment of the resin or its tackiness properties as an adhesive or adhesion promoter presuppose.

By modifying the cyanates with multivalent phenols as defined above, the cure becomes at moderate temperatures (eg 130 or 160 ° C) possible without the intrinsic flame retardancy of pure cyanates is adversely affected (this is not the case in the known modification of the cyanates with epoxides, here the flame retardancy is significantly reduced).

Possibly can the reactivity also by adding known catalysts, e.g. a metal acetylacetonate, changed (continue elevated) as is known in the art.

Surprised Above all, achieving a combination of the above is required Properties that are mostly counter-intuitive by nature, with a single formulation.

worin R¹ bis R⁴ unabhängig voneinander Wasserstoff, C₁-C₁₀-Alkyl, C₃-C₈-Cycloalkyl, C₁-C₁₀-Alkoxy, Halogen (F, Cl, Br oder I), Phenyl oder Phenoxy ist, wobei die Alkyl- oder Arylgruppen fluoriert oder teilfluoriert sein können. Beispiele sind Phenylen-1,3-dicyanat, Phenylen-1,4-dicyanat, 2,4,5-Trifluorophenylen-1,3-dicyanat;

worin R⁵ bis R⁸ wie R¹ bis R⁴ sind und Z eine chemische Bindung, SO₂, CF₂, CH₂, CHF, CH(CH₃), Isopropylen, Hexafluoroisopropylen, C₁-C₁₀-Alkylen, O, NR⁹, N=N, CH=CH, COO, CH=N, CH=N-N=CH, Alkylenoxyalkylen mit C₁-C₈-Alkylen, S, Si(CH₃)₂ oder

The choice of multifunctional cyanates to be used as starting material for the resin is not critical. In principle, any at least bifunctional cyanate body can be used, including, in particular, aromatic cyanates and, among these, in particular, especially di- or polyfunctional cyanates of the structures I-III listed below:

in which R ¹ to R ^4, independently of one another, are hydrogen, C ₁ -C ₁₀ -alkyl, C ₃ -C ₈ -cycloalkyl, C ₁ -C ₁₀ -alkoxy, halogen (F, Cl, Br or I), phenyl or phenoxy, wherein the alkyl or aryl groups may be fluorinated or partially fluorinated. Examples are phenylene-1,3-dicyanate, phenylene-1,4-dicyanate, 2,4,5-trifluorophenylene-1,3-dicyanate;

in which R ⁵ to R ^{8 are} as R ¹ to R ⁴ and Z is a chemical bond, SO ₂ , CF ₂ , CH ₂ , CHF, CH (CH ₃ ), isopropylene, hexafluoroisopropylene, C ₁ -C ₁₀ -alkylene, O, NR ⁹ , N = N, CH = CH, COO, CH = N, CH = NN = CH, alkyleneoxyalkylene with C ₁ -C ₈ -alkylene, S, Si (CH ₃ ) ₂ or

worin R⁹ Wasserstoff oder C₁-C₁₀-Alkyl ist und n eine ganze Zahl von 0 bis 20 bedeutet, sowie
di- oder mehrfunktionelle aliphatische Cyanate mit mindestens einem Fluoratom im aliphatischen Rest und vorzugsweise der Struktur IV: N≡C-O-R¹⁰-O-C≡N IVworin R¹⁰ ein zweibindiger organischer nichtaromatischer Kohlenwasserstoff mit mindestens einem Fluor-Atom und insbesondere mit 3 bis 12 Kohlenstoffatomen ist, dessen Wasserstoffatome vollständig oder teilweise durch weitere Fluor-Atome ersetzt sein können.Examples are 2,2-bis (4-cyanato-phenyl) propane, 2,2-bis (4-cyanato-phenyl) hexafluoropropane, biphenylene-4,4'-dicyanate;

wherein R ^{9 is} hydrogen or C ₁ -C ₁₀ -alkyl and n is an integer from 0 to 20, as well as
di- or polyfunctional aliphatic cyanates having at least one fluorine atom in the aliphatic radical and preferably of structure IV: N≡COR ¹⁰ -OC≡N IV wherein R ¹⁰ is a divalent organic non-aromatic hydrocarbon having at least one fluorine atom, and in particular having 3 to 12 carbon atoms whose hydrogen atoms may be wholly or partially replaced by further fluorine atoms.

The mentioned cyanates can as monomers or as prepolymers, alone or in mixtures with one another or in admixture with other monofunctional or polyfunctional Cyanates are used.

Examples of readily suitable cyanates are the dicyanate of bisphenol A (4,4'-dimethylmethylene-diphenyl-dicyanate), 4,4'-ethylidenediphenyl-dicyanate or compounds of the formula III wherein n is 1, 2 or 3, R ^{9 is} hydrogen and each methylene group is ortho to the cyanate group.

The to be used multifunctional (multivalent) aromatic or Aliphatic alcohols are preferably compounds of the above for cyanates specified structures I to IV, in which the cyanate groups by Hydroxy groups are replaced. Of course, mixtures of alcohols as defined above.

Preferably are the multivalent aromatic alcohols around multivalent phenols. Instead, however, e.g. condensed Aromatics are used such. Naphthol. Especially Preferably, the multivalent phenols or other Aromatics to divalent (difunctional) alcohols. The hydroxy group is each bound directly to the aromatic ring.

When examples for bisphenols which are very suitable are bisphenol A, 4,4'-ethylidenediphenol or bis-hydroxyphenylsulfide called.

The Material of the filler (s) to be added optionally is not critical. In this regard, can on usual fillers such as. Microfiller are referred as they are as reinforcing materials are used in duromers, ie fillers with a particle size distribution, their center of gravity in the μm range lies. But also nanofillers with smaller grain sizes (particle size distribution with emphasis below the μm range) possible. Independently whether microfillers and / or nanofillers will be used these are preferably selected under inorganic fillers, which may optionally be organically modified and / or coated can. Unless the fillers contain organophosphorus constituents, they strengthen the fire safety. Suitable materials include silica, ceramic Materials, organically modified silicones or siloxanes or Mixtures thereof, in particular those with very high surface areas and / or small grain sizes.

The fillers can used alone or in mixture. As very suitable have mixtures of different fillers from different Materials proved. Their proportion in the resin may preferably be up to 20% by mass.

Optional can the starting material for the resins further additives or such additives are prepolymerized in the Resin later incorporated. examples for such additives are surface-modifying, e.g. the surface tension lowering agents such as fluorocarbon-modified polymers.

Especially surprising could be determined according to the invention be that additive of fillers To the proposed Cyanatharzmassen a higher toughness of the cured masses causes.

to Preparation of the prepolymer are the or the cyanate components and the one or more multifunctional alcohols in suitable proportions in terms of the above Molar ratios of OCN to OH usually separated or together in a suitable solvent solved. The alcohol component Accordingly, it is usually added in a ratio of 2 to 20% by mass become. solvent for cyanate ester resins are known in the art; a common one used is methyl ethyl ketone. If the solutions are prepared separately, they will be afterwards mixed well.

Optionally, a further catalyst can be added to accelerate the crosslinking, as known from the prior art, for example a metal acetylacetonate complex. Alternatively, the reactants can also be mixed together directly, without a solvent for Ein sentence comes.

Provided the prepolymer should contain one or more fillers, these may one of the solutions or the single or combined solution of the cyanate and alcohol components (or, if working in the absence of solvent, the solvent-free Mixture or one of the starting components therefor) to a be added at any time. The dispersion takes place usually with the usual for this Aids. The solution or dispersion, which is optionally concentrated to a suitable viscosity or diluted can, then as cast resin, Glue or bonding agent or for another purpose as above be used specified. Depending on the intended purpose is if necessary, then in the later Form, e.g. as an adhesive or adhesion promoter on a substrate spread over before they are dried under the action of temperature if necessary is, the solvent evaporated and the resin is prepolymerized. The duration of drying and thus the degree of prepolymerization are according to the respective Requirement chosen; However, it should preferably before reaching the so-called gel point lie, allowing a re-melting and thus a subsequent shaping possible is. As a temperature range for the drying is particularly suitable for those between 80 to 200 ° C, without Naturally limited to this to be. Alternatively, the resin may be in bulk form with or without pre-drying be stored. Independently from the obtained form, it is preferable during storage chilled (usually at about 0 to -26 ° C, preferably at -26 ° C). For finishing (deformation and / or solidification under heat input and if necessary) temperatures are usually used between 100 and 200 ° C. In this case, a pressing pressure can be applied. Hardening times of approx. 2 to 20 minutes are the rule. The pressures are the respective processing technology or the desired Product adjust and are usually at about 1 to 20 bar (about 1 bar typically for single layer laminate, about 20 bar typically for multilayer laminates,) without limited to this to be.

below the invention will be explained in more detail by way of examples.

Example Group 1 - general

• Reactions of pure cyanate ester resins (both multifunctional as well as difunctional) with bisphenols

• Example 1.1 Reaction of Primaset PT15 ^® (Lonza) or PT30 of Primaset ^® (Lonza) with Bishydroxyphenylsulfid
• Example 1.2 Reaction of Primaset PT15 ^® or Primaset PT30 ^® with bisphenol A
• Example 1.3 Reaction of Primaset LeCy ^® (Lonza) with Bishydroxyphenylsulfid
• Example 1.4 Reaction of Primaset® ^® LeCy with bisphenol A

The Cyanate ester component as well as the bisphenol component are incorporated in the invention according to claim 1 corresponding proportions dissolved in methyl ethyl ketone (MEK). Typically one expects thereby with approx. 90-70%, preferably approx. 80 Ma-% Resin and 10-30 % By mass, preferably about 20% by mass MEK. Then the solutions are put together and stirring mixed.

With this solution a substrate can be coated. The coated substrate is then under Temperature influence, preferably at about 80 to 130 ° C, dried, i.e. it becomes the solvent evaporated and prepolymerized the resin. The duration of drying and thus the prepolymerization state are in the range of about 1 to 10 minutes, depending from the chosen one Temperature (and concrete resin composition), however, he must Reaching the so-called gel point lie, so a renewed Melting and thus a shaping is possible. The coated ones Substrates are supplied for storage of cooling. For finishing (deformation under temperature and possibly pressure), a temperature of 160 ° C at a Press time of 800s can be used.

Example Group 2 - general

• Implementation of combinations of cyanate ester resins with bisphenols

Example 2.1

• Reacting mixtures of Primaset PT15 ^® and Primaset PT30 ^® with Bishydroxyphenylsulfid

Example 2.2

• Reacting mixtures of Primaset PT15 ^® and Primaset PT30 ^® with bisphenol A

Example 2.3

• Reactions of mixtures of Primaset PT15 and Primaset ^{® ®} LeCy with Bishydroxyphenylsulfid

Example 2.4

• Reacting mixtures of Primaset ^® 2T15 and Primaset ^® LeCy with bisphenol A

Example 2.5

• Reactions of mixtures of Primaset PT30 and Primaset ^{® ®} LeCy with Bishydroxyphenylsulfid

Example 2.6

• Reacting mixtures of Primaset PT30 and Primaset ^{® ®} LeCy with bisphenol A

The Procedure of processing corresponds to the procedure described under 1. The cyanate ester components are dissolved separately and then with the bisphenol solution united. The mass fractions correspond to those described under 1. The ratios the cyanate ester components can in the remaining range over the entire bandwidth chosen become.

Example Group 3 - general

• Beispiel 3.1 Einarbeitung von pyrogener Kieselsäure
• Beispiel 3.2 Einarbeitung von natürlichem und/oder synthetischem quellfähigem Schichtsilikat, insbesondere auf Basis des Montmorillonit-Typs
• Beispiel 3.3 Einarbeitung von anorganischem, phosphathaltigem Flammschutzmittel
• Beispiel 3.4 Einarbeitung von Kombinationen aus den Beispielen 3.1 bis 3.3

Incorporation of auxiliaries to achieve improved surfaces in the cured state, without loss of fire resistance for the resin mixtures of Example Groups 1 and 2

• Example 3.1 Incorporation of Fumed Silica
• Example 3.2 Incorporation of natural and / or synthetic swellable phyllosilicate, in particular based on the montmorillonite type
• Example 3.3 Incorporation of inorganic, phosphate-containing flame retardant
• Example 3.4 Incorporation of Combinations from Examples 3.1 to 3.3

The Incorporation of the excipients into the combined solutions, which were prepared as described under 1 and 2, using of dispersing equipment. The added proportion of the excipients may preferably be in the sum up to 20% by mass, with the addition of a single filler it is preferably at a maximum of about 10% by mass.

Example Group 4

A production of specimens

to Preparation of the specimens the corresponding resin (e.g., B10, XU366 [1,3-phenylene-bis (1-methylethylidene) diphenyldicyanate, to refer to Ciba and Huntsman, respectively], PT15 [oligo (3-methylene-1,5-phenylcyanate, available from Lonza], PT30 [like PT15, but with higher Functionality] or a composition as described in example group 1) weighed into a glass flask and melted at 120 ° C. In case of Use of bisphenol A as a comonomer will be both substances Weighed together in a flask, also melted at 120 ° C. and mixed together. Subsequently, the resulting melt degassed under vacuum and poured into a mold, which on the intended curing temperature preheated. The resin or the mixture is then in the mold in the warming cabinet according to the desired curing regime hardened.

B special examples for specimens

Example 4.1

5.57g Primaset ^® B10 (Lonza) (4,4'-Isopropylidendiphenyldicyanat) are melted and heated to 140 ° C. Into the liquid are added 1.07 g of 4,4'-dihydroxybenzophenone (premixed with 0.05% Co balt (III) acetylacetonate) and the mixture degassed under vacuum for about 10 min. The resulting prepolymer has a storage stability of> 3 weeks at room temperature. The mixture is then poured into a preheated to 100 ° C mold and cured in the oven according to the following heating regime: 15h 160 ° C, 1h 180 ° C. The resulting cured polymer is yellow, clear and has a glass transition temperature Tg = 229 ° C and a modulus G '= 950 MPa (dynamic mechanical analysis).

Example 4.2

5.57g Primaset ^® B10 (Lonza) is melted and heated to 140 ° C. In the liquid 1.25 g of bis (4-hydroxyphenyl) sulfide are added in portions (premixed with 0.04% chromium (III) acetylacetonate), and the mixture is stirred for about 30min at 160 ° C and then degassed under vacuum for 10min. The resulting prepolymer has a storage stability of> 3 weeks at room temperature. The mixture is then poured into a preheated to 120 ° C mold and cured in the oven according to the following heating regime: 15h 160 ° C, 1h 180 ° C. The resulting cured polymer is golden brown, clear and has a glass transition temperature Tg = 237 ° C and a modulus G '= 1110 MPa (dynamic mechanical analysis).

Example 4.3

5.62g Primaset LeCy ^® (Lonza) (4,4'-Ethylidendiphenyldicyanat) are degassed and heated to 70 ° C. In the liquid 0.82 g of bis (4-hydroxyphenyl) sulfide are added in portions (premixed with 0.04% chromium (III) acetylacetonate), and the mixture is stirred for 30 min at 70 ° C and then degassed under vacuum for 10min. The resulting prepolymer has a storage stability of> 3 weeks at room temperature. The mixture is then poured into a preheated to 70 ° C mold and cured in the oven according to the following heating regime: 1h 120 ° C, 2h 140 ° C, 1h 160 ° C. The resulting cured polymer is yellow, clear and has a glass transition temperature Tg = 197 ° C and a modulus G '= 990 MPa (dynamic mechanical analysis) and thermal expansion coefficients of 54 ppm / K below and 163 ppm / K above the glass transition temperature (thermomechanical analysis ) on. At 403 ° C the polymer shows a mass loss of 10% under air (thermogravimetry).

Example 4.4

4.756g Primaset LeCy ^® (Lonza) are degassed and heated to 70 ° C. In the liquid 0.436 g of bis (4-hydroxyphenyl) sulfide are added in portions (premixed with 0.04% chromium (III) acetylacetonate), and the mixture is stirred for about 30min at 70 ° C and then degassed under vacuum for 10min. The resulting prepolymer has a storage stability of> 3 weeks at room temperature. The mixture is then poured into a pre-heated to 70 ° C mold and cured in the oven according to the following heating regime: 2h 100 ° C, 2h 120 ° C, 2h 140 ° C, 1h 160 ° C. The resulting cured polymer is yellow, clear and has a glass transition temperature Tg = 222 ° C and a modulus G '= 1010 MPa (dynamic mechanical analysis).

C Properties of specimens

The Table I below gives minimum temperature profiles for the curing of with bisphenol A modified Cyanatesterharzen, which is a acceptable fracture toughness give and in the prepolymerized state at room temperature a storage stability of 3 weeks. For comparison, corresponding data from unmodified cyanate ester resins indicated.

Tabelle I

Table I

Abbreviations:

• K1c = Critical Stress Intensity Factor in Mode 1
• (Mode 1 = tensile load)

In Table II below shows the fire properties of three the resin pairs listed in Table I. (unmodified / modified).

Tabelle II

Table II

Abbreviations:

• Flam. = Inflammation time
• HRRpeak = Heat Release Rate peak
• HRR300 = heat release rate over 300 sec.
• THR300 = Total is released (total heat release within 300 sec.
• TSR = Total smoke released

The fire properties of the substances from Table II are in 1 shown graphically.

Claims (18)

A prepolymer prepared using (a) at least one di- or polyfunctional organic cyanate and (b) at least one di- or polyfunctional aromatic alcohol and / or at least one di- or po lyfunktionellen aliphatic, in the aliphatic radical with at least one fluorine atom substituted alcohol in proportions which ensure a molar ratio of the OCN groups to OH groups in the starting materials for the preparation of the prepolymer 95: 5 and 70:30, and optionally at least one filler with the exception of a prepolymer consisting of the dicyanate derivative of bisphenol A and bisphenol A and / or a brominated derivative thereof, and with the exception of prepolymers made using exclusively aliphatic dicyanates and excluding aliphatic diols. A prepolymer according to claim 1, wherein the di- or polyfunctional organic cyanate or one of these cyanates is selected from aromatic cyanates and preferably among cyanates of the formulas I to III:

wherein R ¹ to R ^{4 are} independently hydrogen, straight or branched C ₁ -C ₁₀ alkyl, C ₃ -C ₈ cycloalkyl, C ₁ -C ₁₀ alkoxy, halogen, phenyl or phenoxy, wherein the alkyl or aryl groups fluorinated or partially fluorinated,

in which R ⁵ to R ^{8 are} as R ¹ to R ⁴ and Z is a chemical bond, SO ₂ , CF ₂ , CH ₂ , CHF, CH (CH ₃ ), isopropylene, hexafluoroisopropylene, C ₁ -C ₁₀ -alkylene, O, NR ⁹ , N = N, CH = CH, COO, CH = N, CH = NN = CH, alkyleneoxyalkylene with C ₁ -C ₈ -alkylene, S, Si (CH ₃ ) ₂ ,

wherein R ^{9 is} hydrogen or C ₁ -C ₁₀ alkyl and n represents a value of 0 to 20, as well as prepolymers of the aforementioned cyanates. Prepolymer according to claim 1 or 2, characterized in that the di- or polyfunctional alcohol or one of these alcohols is selected from polyfunctional, preferably bifunctional phenols (Bis phenols). Prepolymer according to claim 1 or 2, characterized that the di- or polyfunctional aromatic alcohol or a selected from these alcohols is among compounds having the structures specified in claim 2 for cyanates I to III, in which the cyanate groups are replaced by hydroxyl groups are. Prepolymer according to one of the preceding claims, characterized characterized in that the di- or polyfunctional organic cyanate or one of these cyanates is selected among novolak cyanates, the bisphenol A dicyanate derivative, is 4,4'-ethylidene diphenyl dicyanate and compounds of the formula III according to claim 2, wherein n is 1, 2 or 3, R9 is hydrogen and the methylene group is in each case ortho position to Cyanate and / or that the di- or polyfunctional aromatic Alcohol or one of these alcohols is selected from bisphenol A and Bishydroxyphenylsulfid. Prepolymer according to one of the preceding claims, comprising at least one filler, the selected is among microfillers and / or nanofillers of inorganic, optionally organically modified and / or coated material. A prepolymer according to any one of the preceding claims wherein the or at least one of the fillers organophosphorus Contains ingredients. A prepolymer according to any one of claims 6 or 7 wherein the or at least one of the fillers selected is organically modified under silica, ceramic materials Silicones or siloxanes or mixtures thereof, in particular those with very high surfaces and / or small grain sizes. A prepolymer according to any one of claims 6 to 8, wherein the filler content the mixture up to 30% by mass, preferably up to 20% by mass and stronger preferably up to 15% by mass. A prepolymer according to any one of the preceding claims wherein the mixture has at least one additional additive. The prepolymer of claim 10, wherein the additive is selected under surface-modifying, preferably the surface tension lowering means. Process for producing a prepolymer such as in one of the claims 1 to 11, characterized by: - Mix from or separately or jointly solve (a) at least a di- or polyfunctional organic cyanate and (B) at least one di- or polyfunctional aromatic alcohol and / or at least one di- or polyfunctional aliphatic, substituted in the aliphatic radical with at least one fluorine atom Alcohol in proportions containing a molar ratio of OCN groups to OH groups ensure the mentioned materials between 95: 5 and 70:30, in one or in different solvents and, provided the release in separate solvents he follows, - then combining the solutions, with the exception of mixing or separate or joint dissolution of the Dicyanate derivative of bisphenol A and bisphenol A and / or a brominated derivative thereof, as well as with the exception of mixing or separate or joint solution of exclusively one or more aliphatic dicyanates and one or more aliphatic diols. The method of claim 12, further comprising the step of incorporating at least one filler in one, into which (only) or in the combined solution (s). The method of claim 12 or 13, further comprising the step of adjusting the viscosity of the resulting solution Evaporation or addition of solvent. The method of any of claims 12 to 14, further comprising the transfer of the if necessary concentrated solution in a shape close to the final shape and heating and / or Dry the mixture. The method of any of claims 12 to 14, further comprising heating and / or drying the solution in bulk form. A method according to any one of claims 12 to 16, wherein the drying between 80 and 200 ° C he follows. Shaped or laminated body obtained by or under Use of a prepolymer according to one of claims 1 to 11 and hardening the same using increased pressure compared to room conditions and / or elevated Temperature.