EA005231B1 - Thermosetting resin-rubber composite and method and apparatus for the manufacture thereof - Google Patents

Abstract

1. A thermosetting resin composition comprising: a particulate thermosetting phenol-aldehyde resin; and a particulate curing agent for said thermosetting resin, said curing agent being encapsulated in a water insoluble thermoplastic resin having a softening point higher than, (1) the melting point of said thermosetting resin and, (2) the temperature at which said thermosetting resin flows on a solid substrate, said encapsulating thermoplastic resin also being dissolvable in said thermosetting resin by heating; said curing agent being capable of curing said thermosetting resin upon melting of said encapsulating thermoplastic resin and release thereof. 2. The thermosetting resin composition of claim 1 wherein said encapsulated curing agent comprises particles dispersed substantially homogeneously throughout said thermosetting resin. 3. The thermosetting resin composition according to claim 1, wherein said encapsulated curing agent is a microcapsule-type curing agent being an emulsion-type microcapsule curing agent formed from an emulsion containing said curing agent and said water insoluble thermoplastic resin as a particle material. 4. The thermosetting resin composition according to claim1, wherein said encapsulated curing agent has a mean particle diameter in the range of 30 mum to 50 mum. 5. The thermosetting resin composition of claim 1 wherein said particulate thermosetting resin has a mean particle diameter in the range of 30 mum to 50 mum. 6. The thermosetting resin composition according to claim 1 wherein said thermoplastic encapsulating agent is a propylene/ethylene/butadiene block copolymer, polyamide, melamine, epoxy, styrene and acrylic, glycidal and acrylic copolymer. 7. The thermosetting resin composition according to claim 1 wherein said curing agent is hexamethylentetramine, paraformaldehyde, hexamethoxymelamine, trimellitic anhydride, an epoxy resin, a phenol resolic resin, a melamine resin, a prereacted epoxy-polyester resin, meta-triphenyl phosphine and quartenary ammonium salt. 8. The thermosetting resin composition according to claim 1 comprising a prepreg containing said thermosetting resin and said encapsulated curing agent. 9. The thermosetting resin composition of claim 1 wherein said phenol-aldehyde resin is a novolac. 10. The thermosetting resin composition of claim 1 wherein said phenol-aldehyde resin is a novolac having a molecular weight between about 300 and 2000. 11. The thermosetting resin composition of claim 1 wherein said phenol-aldehyde resin is a novolac formed by formed by condensation of a phenol component comprising at least one bifunctional phenol with at least one aldehyde component represented by the formula: R-CHO wherein R represents a hydrogen atom, a methyl group or a halogenated methyl group. 12. The thermosetting resin composition of claim 11 wherein said phenol-aldehyde resin is a phenol-formaldehyde resin. 13. The thermosetting resin composition of claim 1 wherein at least one particle of said particulate encapsulated curing agent is adhered to at least one particle of said thermosetting resin. 14. A curing agent for a thermosetting phenol-aldehyde resin, said curing agent being encapsulated in a water insoluble thermoplastic resin having a softening point higher than, (1) the melting point of said thermosetting resin and, (2) the temperature at which said thermosetting resin flows on a solid substrate, said encapsulating thermoplastic resin also being dissolvable in said thermosetting resin by heating; said curing agent being capable of curing said thermosetting resin upon melting of said encapsulating thermoplastic resin and release thereof. 15. The curing agent of claim 14 in particulate form. 16. The curing agent of claim 15 comprising particles having a mean particle diameter in the range of 30 mum to 50 mum. 17. The curing agent of claim 14 wherein said encapsulating curing agent is a microcapsule-type curing agent being an emulsion-type microcapsule curing agent formed from an emulsion containing said curing agent and said water insoluble thermoplastic resin as a particle material. 18. A method for curing a thermosetting phenol-aldehyde resin comprising contacting said resin with the curing agent of claim 14 and heating said resulting combination to a temperature above the melting point of said encapsulating thermoplastic resin. 19. The method of claim 18 wherein said thermosetting resin is in particulate form. 20. The method of claim 18 wherein said curing agent comprises particles substantially homogeneously distributed throughout said thermosetting resin. 21. The method of claim 18 wherein said curing agent comprises particles having a mean particle diameter in the range of 30 mum to 50 mum. 22. The method of claim 18 wherein said particulate thermosetting resin has a mean particle diameter in the range of 30 mum to 200 mum. 23. The method of claim 19 wherein at least one particle of said particulate encapsulated curing agent is adhered to at least one particle of said thermosetting resin. 24. The method of claim 18 wherein said combination is cured in the presence of a substrate that is substantially chemically inert with respect to said thermosetting resin and said curing agent. 25. The method of claim 24 resulting in the formation of a composite material comprising cured thermoset resin and said substrate. 26. The method of claim 25 wherein said composite comprises said substrate substantially surrounded by a matrix comprising said thermoset resin. 27. The method of claim 25 wherein said substrate is fiberglass. 28. A process for producing materials consisting of a mass of mutually linked inorganic fibers, comprising linking the fibers at localized fiber-fiber junctions or knots by distributing particles of a binding material and of a cross linking agent within the fiber mass and activating said binding material and cross linking agent be heating said material and agent to their respective melting temperatures, wherein said cross linking agent has a higher melting point than said binding material. 29. A process according to Claim 28, wherein said binding material and said cross linking agent are in the form of a powder. 30. A process according to Claim 28, wherein said binding material is in the form of an aqueous dispersion (slurry) of a phenolic resin. 31. A process according to Claim 28, wherein said binding material consists of a phenolic resin and said cross linking consists of a derivative of formaldehyde coated with a film of material having a melting point higher than that of the phenolic resin. 32. A process according to Claim31, wherein said formaldehyde derivative consists of a hexamethylenetetramine powder encapsulated in a coating of a material having a higher melting point than the said phenolic resin, said coating comprising a block copolymer of the propylene-ethylene-butylene type. 33. A process according to Claim 32, characterized in that said binding material consists of a phenolic resin and that said cross linking agent is chosen from among one or more of the following compounds: -paraformaldehyde - hexamethoxymelamine - trimellitic anhydride - epoxy resins - resol-type phenolic resins - melamine resins - prereacted epoxy-polyester resins. 34. Apparatus for producing a mass of mutually linked inorganic fibers comprising a first furnace for melting glass inorganic material, a die connected to said furnace for obtaining a flow of molten glass, a rotatable spinneret disposed to receive said flow and form a plurality of glass fibers passed through openings in the spinneret as it is rotated, flame deflectors disposed in the path of the fibers for directing heat on the fibers passed onto a conveyor belt disposed below the fibers and means adjacent the fibers for simultaneously dispersing a of binding material and a powdered cross linking agent within the mass formed by said fibers prior to the fibers being passed onto the conveyor belt. 35. Apparatus according to Claim 34, characterized in that it also contains a second furnace for receiving the fibers on the conveyor belt and heating said fiber up to the melting temperature of said binding material and said cross linking agent, respectively. 36. Apparatus according to Claim 35, wherein said second furnace comprises two sections through which said fibers pass, each said section adapted to operate at a different temperature, the second section having an operating temperature greater than the operating temperature of the first section.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to composite structural materials consisting of thermosetting resins and a fibrous amplifier or filler, as well as to a method for manufacturing such materials.

State of the art

Currently, as you know, in construction, various materials are widely used in the form of panels, rolls or in any other form, containing glass wool, mineral wool, slag wool and other inorganic fibers enclosed in a cured binder, in particular a thermosetting resin.

Typically, such building materials are made by spraying on fiberglass, glass wool or similar material with an aqueous solution of phenol-formaldehyde resin, optionally with the addition of urea, followed by its crosslinking on the fibers by heat treatment, resulting in a finished product with a dense insulating structure.

A drawback of such currently known manufacturing methods of the building materials mentioned above is that they do not allow controlling the distribution of the resin over the surface of single fibers. An irregular or random distribution of the resin sprayed onto the fibers is accompanied after curing by a random arrangement of cross-links along the entire length of the fibers, stiffening of the fibers and the formation of a rigid structure that is easily destroyed during subsequent operation with the finished product. When the fibers are destroyed, in addition, separate, very small particles with a certain toxicity are formed, which, when released into the environment, create serious environmental problems. The problem associated with the uncontrolled distribution of resin over the surface of the fibers is further aggravated by the fact that the curing of the resin, which results in the mechanical connection of the individual fibers, is accompanied by the formation of several layers of solid material on fiberglass, which further increase the fragility of the finished product and make its less suitable for future use. The disadvantages of the known methods also include increased consumption of resin, the associated relatively high cost of the resulting product and the high cost of disposing of waste contaminated with polymer decomposition products and other chemical products mixed with them.

Summary of the invention

The present invention relates to a new method and a new installation for the manufacture, in particular, of heat and sound insulating materials intended for use in construction and industry. The method proposed in the invention allows the manufacture of new composite materials from thermosetting phenol-aldehyde, for example novolac, resins with a fibrous filler, which differ favorably from known materials of a similar type by their lower stiffness and thus the greater strength of the final product made from them, as well as by the lower cost of serving as their binder (continuous phase) of the resin.

The invention also relates to (1) a system or installation for implementing the method of the invention, (2) a composition used for the manufacture of the above materials, and (3) products made from such materials.

Brief Description of the Drawings

Below the invention is described in more detail with reference to the drawings, in which is shown in FIG. 1 is a setup diagram illustrating the main steps of the method of the invention;

in FIG. 2 is a diagram showing in more detail one of the assemblies of the apparatus of the invention in which the binder is set on the glass fibers connected by it;

in FIG. 3 is an example of an article manufactured by the method of the invention; and in FIG. 4-6 are separate steps of the process illustrated in FIG. 2.

Preferred Embodiments

The above-mentioned, as well as other objectives of the invention are solved using the method, installation, composition, and products obtained using this composition and proposed in detail below.

The present invention allows to eliminate the structural rigidity of the fibers and thereby increase the mechanical strength of the composite material containing such fibers. The invention also allows to reduce the amount of binder resin used in the manufacture of composite material, and thereby reduce the cost of its manufacture and disposal of waste.

These and other objectives, features and advantages of the invention are described in more detail below in the description of preferred options for its possible implementation with reference to the relevant drawings.

The inventive method implemented in a plant, a diagram of which is shown in FIG. 1 begins with obtaining a mass of molten material, from which fibers are then formed, in this case, obtaining mass 1 of molten glass in a melting furnace 2, which passes through the head 3 and forms a stream 4 of molten glass. The molten glass flowing out of the furnace enters the collector 5 of a device for forming fibers or an annular die 6 rotating at a high speed. Holes 7 are made in the outer wall of the annular die, through which individual fibers exit under the action of centrifugal force 8. The fibers exiting the die by means of a flame made in the form of burners of reflectors 10 are fed to a conveyor belt 9 passing under the dies. On the conveyor belt 9, a mass consisting of individual fibers is formed from the fibers incident on it or mat 16 glass wool, the thickness of which can be adjusted depending on the duration of the dies 6.

The molten glass fibers 8 collected on a conveyor belt 9 are treated with a phenol-formaldehyde binder resin sprayed with spray guns 11, prepared in the form of a dry powder or its aqueous suspension. The molten glass fibers 8 are also treated with a sprayable particulate material prepared from a powder or suspension of phenol-formaldehyde resin and a cross-linking agent powder, and the final product is obtained from them in the form of a mat 16 (Fig. 3). The binder is fed through a double-walled pipe 15, which allows you to adjust the temperature of the binder accordingly. The flow of water and a binder, which come from a separate tank, is controlled using appropriate pressure and flow controllers. The particle size of the powder catalyst in the presence of which the resin cures occurs is preferably from 0.5 to 2.5 microns.

The mats 16 composed of fibers thus treated pass through a furnace 12 with two heating sections 13, 14 in which a different temperature is maintained, in particular through a section 13 in which the phenol-formaldehyde resin is heated to its melting temperature (usually to 105 ° C). The bulk of the molten mass of the resin, together with the catalyst particles enclosed in the shell, forms separate drops of resin in the nodes of the mat (Figs. 4-6).

In this case, in particular, the molten resin moves along the fiber under the influence of surface tension and collects at the crossing points of two adjacent fibers located in the entire mass of fibers. The sliding of the resin over the surface of the fiber to the point of crossing with another fiber is stimulated by a corresponding change in the surface tension between the resin and the fiber, which depends on the amount of water emulsion added to the suspension, which is preferably from 1.5 to 5% based on the weight of phenol-formaldehyde resin . The presence of a surfactant promotes the formation of a thin layer of phenol-formaldehyde resin on the molten glass fibers and reduces the fragility of the fibers. If necessary, novolak fluidity can also be changed. It was found that it is possible to increase the novolak fluidity on the surface of the glass fiber by alkoxylating a certain amount (about 5%) of its phenolic OH groups (ethylene or propylene carbonate or ethylene or propylene oxide).

In addition, in contrast to the known methods in which liquid resol is sprayed on the glass fiber, the invention proposes another more effective solution, which consists in processing the glass fiber with a high-speed sprayed aqueous suspension (not solution) of solid novolak and hardener. In this case, the glass plays the role of a kind of filter in which the particles of the suspension are essentially physically held at the fiber crossing points.

In section 14, the mat is heated to the melting temperature of the shell of the catalyst enclosed in the shell (temperature exceeding 105 ° C), as a result of which the cross-linking or crosslinking reaction begins in the resin, which is accompanied by the formation of a layer of cured material, connecting adjacent fibers at their places crossing and the formation of a dense structure 16 (Fig. 6). The stiffness of such a structure is determined by the stiffness of the nodes or intersection points of individual fibers 8, interconnected in these nodes by phenol-formaldehyde resin, which is collected in molten form in these places as a result of a decrease in surface tension.

In this way, it is possible to produce heat and sound insulating material 16 (Fig. 3), which differs from known materials of a similar type in greater strength, is more convenient to handle and does not spray harmful particles of cured resin polluting the environment.

In phenol-formaldehyde resin, a suitable crosslinking agent or hardener is dispersed in the form of a powder enclosed in a shell, the shell of which melts or decomposes at a temperature higher than the melting temperature of the phenol-formaldehyde resin. The average particle diameter of the hardener enclosed in the shell is from 30 to 50 microns.

As the high molecular weight substituted phenolaldehyde resin of the novolac type, which is part of the curable composition of the present invention, any substantially linear high molecular weight substituted phenolaldehyde resin of the novolac type can be used, the main component of which is the phenolic component, consisting mainly of bifunctional phenol, which is used in coating and construction. The high molecular weight substituted phenolaldehyde resin of the novolac type (hereinafter referred to as the high molecular weight novolac resin), which is used in the present invention, may contain essentially linear repeating units of the novolac type or intermediate or bridging groups containing a divalent hydrocarbon group that is alternately present in the units of the repeating novolac units . In the context of the present description, the expression essentially linear means that the molecular structure of the polymer is a linear structure that includes straight or branched chains, but practically does not contain cross-links (thickened parts). Such novolac resins are described in I8 4342852 and several other publications.

Typical high molecular weight substituted phenol aldehyde resins of the novolac type that can be used in the practice of the present invention typically contain substantially linear repeating units resulting from the condensation of the phenolic component containing from 70 to 100 mol%, preferably from 80 to 100 mol%, most preferably from 90 to 100 mol% of at least one bifunctional phenol of the general formula [I]: (Κ ') ₃ -Ζ (ΟΗ) - (Κ) ₂ , in which Ζ (ΟΗ) is phenol, two of the three I' are hydrogen atoms, and the third self denotes an alkyl group with 1-8 carbon atoms, an aryl group with 6-10 carbon atoms, a halogen atom or a hydroxyl group, preferably an alkyl group with 1-8 carbon atoms, more preferably represents a substituent selected from the group consisting of methyl, ethyl, isopropyl, a sec-butyl, tert-butyl and octyl group, and two I, which may have identical or different meanings, denote a structural element selected from the group consisting of a hydrogen atom, an alkyl group with 1-8 carbon atoms, a halogen atom and a hydro a strong group. In a preferred embodiment, one of the two I represents a hydrogen atom, and the other I represents a hydrogen atom or an alkyl group with 1-8 carbon atoms. Most preferred are phenols in which both I are hydrogen atoms and in which up to 30 mol%, preferably up to 20 mol%, most preferably up to 10 mol%, is a trifunctional phenol with at least one aldehyde component of the formula [II]: I ^{2 is} CHO, in which I ² represents a hydrogen atom or a substituent selected from the group consisting of a methyl group and a halogenated methyl group, preferably a hydrogen atom or a methyl group, most preferably a hydrogen atom.

The novolac type repeating units that make up the high molecular weight novolac resin form a substantially linear chain structure in which the aforementioned hydroxyarylene and alkylidene units are alternately arranged and connected to each other. The repeating units of the novolac type that make up the high molecular weight novolac resin have a structure in which, when the phenol consists only of bifunctional phenol represented by the general formula [I], the resin has a linear structure, and as the content of trifunctional phenol increases, the resin sometimes becomes branched structure. The ratio between the content of the aldehyde component and the total content of the phenolic component in the repeating units of the novolac type is such that the amount of the aldehyde component per mole of the total amount of the phenolic component is usually from 0.90 to 1 mol, preferably from 0.93 to 1.0 mol . Typically, the repeating units of the novolac type do not contain methylol groups, which, however, may be contained in very small amounts not exceeding, for example, 0.01 moles per mole of the total amount of the phenolic component.

In the phenolic component of the repeating units of the novolac type, of which the high molecular weight novolac resin (B) is composed, the bifunctional phenol is a phenol of the above general formula [I] containing two active hydrogen atoms in the benzene core, by which a substitution reaction is possible. Such a bifunctional phenol is, in particular, a phenol of the general formula [I], which contains an alkyl group with 1-8 carbon atoms, an aryl group with 6-10 carbon atoms, a halogen atom or a hydroxyl group in the ortho or para position with respect to hydroxyl group. Examples of such phenols are the ortho and para isomers of alkyl phenols, such as cresol, ethyl phenol, n-propyl phenol, isopropyl phenol, n-butyl phenol, sec-butyl phenol, t-butyl phenol, sec-amyl phenol, heptyl phenol, heptyl phenol halogenated phenols, such as fluorophenol, chlorophenol and bromophenol; and aryl phenols, such as phenylphenol and tolylphenol. Bifunctional phenols represented by the above general formula [I] also include 2,3-xylene, 3,4-xylenol, 2,5-xylene, 2,3-diethylphenol, 3,4-diethylphenol, 2,5-diethylphenol,

2.3-diiozopropylphenol, 3,4-diiozopropylphenol, 2,5-diiozopropylphenol, 2,3-dichlorophenol,

3.4-dichlorophenol, 2,5-dichlorophenol, 2-methyl-3-phenylphenol, 3-methyl-4-phenylphenol and 2-methyl5-phenylphenol. The bifunctional phenolic component in the novolac type repeating units that make up the high molecular weight novolac resin (B) may be at least one of the phenols listed above, as well as a mixture of two or more of these phenols.

The trifunctional phenol, which may be present in the repeating units of the novolac type, of which the high molecular weight novolac resin (B) is composed, is phenol, which contains three active hydrogen atoms in the benzene core, by which a substitution reaction is possible, and phenol can be mentioned as an example metasubstituted phenols and 3,5-substituted phenols. The substituents that the trifunctional phenol contains in the meta or 3,5 position include alkyl groups, halogen atoms and hydroxyl groups. Among these trifunctional phenols, phenols represented by the general formula [III] are preferred: [K] ₂ , in which K represents a hydrogen atom, an alkyl group with 1-8 carbon atoms, a halogen atom or a hydroxyl group, both K may have identical or different meanings.

Specific examples of such a trifunctional phenol include phenol, metasubstituted phenols, such as mcresol, m-ethylphenol, mn-propylphenol, misopropylphenol, mn-butylphenol, m-sec-butylphenol, m-tert-butylphenol, m- n-amylphenol, m-sec-amylphenol, m-tert-amylphenol, mexylphenol, m-heptylphenol, m-octylphenol, mfluorophenol, m-chlorophenol, m-bromophenol and resorcinol, and 3,5-disubstituted phenols, such as 3, 5-xylenol, 3,5-diethylphenol, 3,5-diisopropylphenol, 3,5-di-sec-butylphenol, 3,5-di-tert-butylphenol, 3,5-di-sec-amylphenol, 3,5di-tert- amylphenol 3,5-digex lfenol, 3,5-digeptilfenol, 3,5-dioktilfenol, 3,5-dichlorophenol, 3,5-difluorophenol, 3,5-dibromophenol and

3.5-diiodophenol. Among such trifunctional phenols, phenols represented by the above general formula [III] are more preferred, in which one of the two groups K represents a hydrogen atom, and the other group K represents a hydrogen atom, an alkyl group with 1-8 carbon atoms or a chlorine atom, and phenols in which one of the K groups represents a hydrogen atom and the other K group represents a hydrogen atom, a methyl group, an isopropyl group, a sec-butyl group, a tert-butyl group or an octyl group are the most preferred respectful.

The aldehyde component of the repeating units of the novolac type, which make up the high molecular weight novolac resin (B), can be the aldehyde represented by the above general formula [II]. Examples of such an aldehyde are formaldehyde, acetaldehyde, monochloracetaldehyde, dichloroacetaldehyde and trichloroacetaldehyde. Among these aldehydes, the most preferred are formaldehyde and acetaldehyde, especially formaldehyde. In the high molecular weight substituted phenolaldehyde resin of the novolac type, the aldehyde component is contained in the form of an alkylidene group represented by the general formula [V].

According to the present invention, the repeating units of novolac type (a) containing the above phenolic and aldehyde components may, as indicated above, contain intermediate or bridging groups (hereinafter also referred to as chain extension units) containing a divalent hydrocarbon group which is alternately present in the repeating units links novolak type. A resin of this type is characterized in that the blocks of repeating units of novolac type (a) having a relatively low molecular weight and the links of the chain extender (b) are arranged in alternating order and connected to each other, as a result of which the molecular weight of the resin increases, and, that the blocks of the repeating units of novolac type (a) are attached to the end groups of the resin molecule. The resin of this type, which has the simplest structure, contains two molecules of blocks of repeating units of the novolac type (a) connected to each other by one molecule of a link of the chain extender (b), and the resin closest in structure contains three molecules of blocks of repeating units of novolac type (a) and two extension chain molecules (b), which are arranged in alternating order and connected to each other. In addition, one should also mention another resin, the structure of which is formed by alternating 4 molecules of blocks of repeating units of novolac type (a) arranged in alternating order and three molecules of chain extension units (b), and also a resin, whose structure is arranged in alternating order and η molecules of blocks of repeating units of novolac type (a) and (η-1) molecules of chain extension units (b) connected to each other.

With a very high molecular weight of such links of chain extenders (b), the melting point of the obtained high molecular weight substituted phenolaldehyde resin of the novolac type decreases, and its elasticity, on the contrary, increases. Therefore, if such a resin is present in the composition of the thermosetting resin, it is hardly possible to achieve that it has high heat resistance and mechanical properties. This is what determines the optimal molecular weight of the chain extension link (b), which should be from 14 to 200, especially from 14 to 170.

The high molecular weight novolac resin used in the present invention is obtained by the method of the invention, which consists in the fact that (A) (I) phenol containing basically at least one bifunctional phenol represented by the general formula [I], or (II) substituted phenolaldehyde a novolac type resin containing phenol, consisting mainly of the specified bifunctional phenol, is reacted in the presence of an acid catalyst with an aldehyde represented by the general formula [II], as a result of which shey least 70 mol.% of the phenolic component in the resultant substituted phenolic novolak type resin falls on the bifunctional phenol, the reaction being continued until until average molecular weight of the final novolak type substituted phenolic resin reaches a desired value.

In one preferred embodiment of the invention, the enclosed hardener is a microencapsulated hardener of an emulsion type in the form of a particulate material. Such a hardener is obtained from an emulsion containing a hardener and a water insoluble thermoplastic resin.

In yet another preferred embodiment, the crosslinking agent comprises a formaldehyde derivative, preferably hexamethylenetetramine (hexamine), whose grains or particles are encapsulated in a material whose melting or decomposition temperature is higher than that of phenol formaldehyde resin. Instead of hexamine, high melting point enveloped materials such as paraformaldehyde, hexamethoxymelamine, trimellitic anhydride, epoxy resins, rezene phenol aldehyde resins, melamine formaldehyde resins and prereacted epoxy resins can also be used as a crosslinking agent or hardener.

As the shell material of the crosslinking agent (hardener), it is preferable to use a copolymer of propylene, ethylene and butadiene.

The content of the cured hardener is preferably from about 3 to 12 wt.%, Calculated on the weight of the phenol-formaldehyde resin, and its melting point is usually at least 102 ° C.

The hexamethylenetetramine encapsulated or any other encapsulated hardener from the above can also be used to obtain uniaxially oriented fibrous plastic (i.e. products made by drawing) from phenol-formaldehyde resins, for example, various kinds of gratings, nets and parts used on marine drilling platforms, and other products. It is obvious that the above options do not limit the invention, which does not exclude the possibility of introducing various changes and improvements into them, which should not go beyond the scope of the invention defined by the following claims. So, for example, fiberglass can be replaced with any other inorganic fiber, which does not contradict the tasks set and solved by the invention.

To increase the efficiency and obtain the maximum effect of novolak (it should be noted that the term novolak refers to any thermosetting resins included in the scope of the present invention) in the form of individual particles, for example in the form of a powder, and the hardener enclosed in a shell must be homogeneously mixed with each other for so that, when provided for by the invention, when heating and melting the material of the shell, the hardener enclosed in it can have a proper catalytic effect on novolak. If necessary, fluidity modifiers, such as colloidal silicon dioxide, alumina or calcium stearate, can be added to the mixture of novolak and the hardener enclosed in the shell, which increase the dispersion of the mixture or prevent premature agglomeration, sintering or separation of particles.

When using novolak mixtures with hardener, presented in the form of, for example, granular powders, uniform and complete contact between novolak powder and hardener is provided quite simply by pre-mixing them with each other. However, when mixtures of novolak with a hardener are used as a binder for fiberglass, the presence of a dilute phase in the dispersion of two powders can lead to a significant physical separation of the novolak powder and the hardener enclosed in the shell and insufficient contact of the novolak particles with the hardener particles for effective curing. In these cases, it is recommended to appropriately modify the interacting compounds or to use other methods that can significantly increase or maintain contact between novolak and hardener. The adhesion forces between the novolak and hardener particles need not be too large, but sufficient so that the novolak and hardener particles remain in contact after any mechanical action associated with the dispersion of the particles.

In addition, it should be noted that in the manufacture of the composite materials proposed in the invention, it is necessary to ensure a certain ratio between the particle sizes of novolak and the hardener enclosed in the shell, which should be such that the number and total mass of hardener particles adhering to the individual novolak particles, on average, are maximally closely corresponded to the necessary ratio between the mass of novolak and hardener in the obtained composite material. The easiest way to provide the required mass ratio between novolak and hardener, which is usually 9: 1, is possible when using a hardener, the particle size of which is significantly smaller than the particle size of novolak.

In one embodiment of the invention, the necessary contact between the novolak and the polymer shell of the hardener is ensured by the direct adherence of the hardener particles to the novolak particles. For example, the polyamide used as the hardener shell material can be prepared by well-known methods based on the interaction of diamines or triamines (such as ethylenediamine or diethylenetriamine) with dibasic acid, fatty acid or dimeric acid. Polyamides of this type are usually used in a wide variety of cases requiring the formation of adhesive bonds. By choosing the appropriate acid and amine, it is possible to ensure that at a given elevated temperature, the polyamide easily adheres to the resin having a higher melting point and does not adhere to it at ordinary temperature. The ability of the polyamide to adhere also depends on its temperature and composition, and may be, in particular, related to the glass transition temperature of the polyamide. In this case, the glass transition temperature of the polymer refers to the temperature at which it passes from a solid glassy state to a fluid, sticky or rubbery state.

With a little stickiness of the polyamide, the hardener can be bonded to particles of novolak encased in uniformly contacting it in suitable equipment, for example, in a fluidized bed or on a flat conveyor belt on which hardener particles are added to or sputtered on novolak particles. Contact between hardener particles and novolak particles should occur at a temperature at which the surface of the shell material becomes sticky, but which still remains lower than the melting or glass transition temperature of novolak.

After full contact and adhesion of the hardener particles to the novolak particles, in order to avoid too much agglomeration or melting and clumping of the mixture, the stickiness of the polyamide must be reduced. This can most easily be achieved by cooling the mixture either in a fluidized or in a separated state to a temperature that is significantly lower than the glass transition temperature of the polyamide. So, for example, at a melting point or glass transition of novolac equal to 75 ° C, the glass transition temperature of polyamide should be approximately 60 ° C. Upon contact of novolak particles with hardener particles at a temperature of 60 to 75 ° C, the polyamide adhering to the adhesive or rubber-like state adheres to novolak particles, and after cooling to a temperature below 60 ° C, it becomes solid and does not adhere to novolak particles, which allows a sufficiently high the glass transition temperature of the polyamide to avoid clumping of the mixture during its normal storage before spraying on fiberglass. The residual stickiness of the final product can be further reduced by the addition of inert inorganic fillers, such as talc, colloidal silicon dioxide or another substance.

Polyamide, in which the hardener partially used for encapsulation, remains partially sticky and adheres to it upon contact with novolac. Subsequently, the residual solvent can be removed from the polyamide in a separate technological stage using vacuum at a temperature that excludes the possibility of melting novolac. At the last stage of the method of manufacturing composite materials proposed in the invention, colloidal silicon dioxide or other additives adhering to the remaining sticky surface areas can be used, which reduce the tendency to clump or agglomerate particles during storage of the resulting product or promote free flow of particles.

In another embodiment, a third binder ingredient is added to the mixture of novolak and the cured hardener during uniform dispersion, due to the presence of which weak, but nevertheless sufficient bonds between the particles are formed in the mixture. The amount of such an additional binder ingredient usually does not exceed 5% of the total composition of the mixture. An example of such a third binder ingredient is an emulsion of polyvinyl acetate, lignins, polyesters and other similar materials.

In conclusion, it should be noted that the specific embodiments of the invention discussed above do not exclude the possibility of making other alternative solutions obvious to those skilled in the art or making improvements or changes to these options. In other words, the above preferred options only illustrate, but do not limit the scope of the invention, allowing the possibility of making various changes, which, however, should not violate the basic idea of the invention and go beyond the scope of the following claims.

Claims (36)

CLAIM 1. Composition for producing a composite material containing thermosetting phenolic resin particles and hardener particles for a thermosetting resin encased in a water-insoluble thermoplastic resin, the softening temperature of which is above (1) the melting temperature of the thermosetting resin and (2) the temperature at which thermosetting resin begins to spread on a solid substrate or base, and which, when heated, dissolves in a thermosetting resin, which cures when exposed to a hardener released from its shell during melting of the thermoplastic resin forming the shell. 2. The composition according to claim 1, in which the encased hardener consists of particles that are substantially evenly dispersed in this thermosetting resin. 3. The composition according to claim 1, in which the encased hardener is a microencapsulated emulsion type hardener, obtained from an emulsion containing a hardener and a water-insoluble thermoplastic resin, in the form of a particulate material. 4. The composition according to claim 1, in which the average particle diameter of the encapsulated hardener is from 30 to 50 microns. 5. The composition according to claim 1, in which the average particle diameter of the thermosetting resin is from 30 to 50 microns. 6. The composition according to claim 1, in which the sheath material of thermoplastic resin is a block copolymer of polyethylene, ethylene and butadiene, polyamide, melamine, epoxy resin, a copolymer of styrene and acrylic acid, a copolymer of glycidal aldehyde and acrylic acid. 7. The composition of claim 1, wherein the hardener is hexamethylenetetramine, paraformaldehyde, geksametoksimelamin, trimellitic anhydride, epoxy, phenolic resole resin, melamine resin, pre-reacted epoxy polyether resin metatrifenilfosfin or quaternary ammonium salt. 8. The composition according to claim 1, containing prepreg containing thermosetting resin and encased in a curing agent. 9. The composition according to claim 1, in which the phenolic resin is a Novolac. 10. The composition according to claim 1, in which the phenolic resin is a Novolak with a molecular weight of from about 300 to 2000. 11. The composition according to claim 1, in which the phenol-aldehyde resin is a novolac obtained by condensation of a phenolic component containing at least one bifunctional phenol with at least one aldehyde component represented by the formula I-CHO, in which I denotes a hydrogen atom, methyl group or halogenated methyl group. 12. The composition according to claim 1, in which the phenol-aldehyde resin is a phenol-formaldehyde resin. 13. The composition according to claim 1, in which at least one particle of the encapsulated hardener is bonded by an adhesive bond to at least one particle of the thermosetting resin. 14. A hardener for a thermosetting phenolic resin, encapsulated in a water-insoluble thermoplastic resin, the softening temperature of which is above (1) the melting point of the thermosetting resin and (2) the temperature at which the thermosetting resin begins to spread on a solid substrate or base, and which when heated, dissolves in a thermosetting resin, which hardens when exposed to a hardener released from its shell when melting the thermoplastic resin forming this shell. 15. The hardener according to 14, which is presented in the form of particles. 16. The hardener indicated in paragraph 15, which is presented in the form of particles with an average diameter of from 30 to 50 microns. 17. The hardener according to claim 14, which is a microencapsulated emulsion type hardener, obtained from an emulsion containing a hardener and a thermoplastic resin that is insoluble in water, in the form of a particulate material. 18. The method of curing thermosetting phenolic resin, which consists in the fact that the resin is introduced into contact with the hardener according to claim 14 and heated in contact with the hardener to a temperature above the melting point of the thermoplastic resin that forms the shell of the hardener. 19. The method according to claim 18, in which the thermosetting resin is used in the form of particles. 20. The method according to claim 18, wherein the hardener is in the form of particles that are substantially uniformly distributed in the thermosetting resin. 21. The method according to p, in which the hardener is presented in the form of particles with an average diameter of from 30 to 50 microns. 22. The method according to p, in which thermosetting resin is presented in the form of particles with an average diameter of from 30 to 200 microns. 23. The method according to claim 19, in which at least one particle of the encased hardener is bonded by an adhesive bond to at least one particle of the thermosetting resin. 24. The method according to claim 18, wherein the thermosetting resin, together with the hardener in contact with it, is cured in the presence of a substrate or substrate, which is substantially chemically neutral with respect to the thermosetting resin and the hardener. 25. The method according to paragraph 24, in which receive a composite material consisting of a cured thermosetting resin and a solid substrate or base. 26. The method according to claim 25, wherein the composite material comprises a solid substrate or substrate, which is substantially completely enclosed in a matrix of thermosetting resin. 27. The method according to p. 25, in which the solid substrate or base is a fiberglass. 28. A method of producing a composite material consisting of a mass of interconnected inorganic fibers, consisting in that the fibers in the ground or in the nodes of intersection of adjacent fibers are interconnected by distributing in the mass of fibers of particles of material having the composition described in claim 1, followed by it is activated by heating to the melting temperature of the thermosetting phenol-aldehyde resin contained in the composition of the material, and then cure to the melting temperature of the shell of the material contained in the composition A, which is higher than the melting point of a thermosetting phenol-aldehyde resin. 29. The method according to claim 28, wherein the material dispersed in a mass of fibers is used in the form of a powder. 30. The method according to claim 28, in which the thermosetting phenol-aldehyde resin contained in the material is used in the form of an aqueous dispersion (suspension). 31. The method of claim 28, wherein the hardener contained in the material is a formaldehyde derivative coated with a film of a material whose melting point is higher than the melting point of the phenol-aldehyde resin. 32. The method of claim 31, wherein the formaldehyde derivative is powdered hexamethylene tetramine coated with a material whose melting point is higher than the melting temperature of the phenolic resin and which is a block copolymer of propylene, ethylene and butadiene. 33. The method of claim 32, wherein one or more compounds selected from the group comprising paraformaldehyde, hexamethoximelamine, trimellitic anhydride, epoxy resins, resole phenolic resins, melamine formaldehyde resins and previously reacted epoxy polyester resins are used as a hardener. 34. Installation for producing a composite material, which is a mass of inorganic fibers interconnected using the composition according to claim 1, having a first furnace for melting inorganic glass material, connected to the furnace head, designed to produce a jet of molten glass, rotating the spinneret into which the jet falls molten glass and in which a multitude of glass fibers are formed, coming out of the holes of the rotating die, burners made in the form of burners, moving along the way Fiber fibers and heat flux guides to fibers collected on the bottom of the conveyor belt, and devices located near the fibers that simultaneously disperse particles formed in the fiber mass before they fall on the conveyor belt, having the composition described in claim 1. 35. Installation according to claim 34, having a second furnace, into which fibers collected on a conveyor belt fall, heated in this furnace to the melting temperature of the thermosetting phenol-aldehyde resin contained in the material, and then to the melting temperature of the shell of the hardener contained in the material. 36. Installation according to p. 35, in which the second furnace consists of two sections operating at different temperatures, through which the fibers pass, which in the second section are heated to a higher temperature than in the first section.