SUBSTANCE: invention relates to composite materials which can be used in aircraft construction. The composite material is made from aramid type fibre reinforcement (bundle) and a composition consisting of a mixture of epoxy resins as a polymer matrix and an aromatic amine as a hardening agent, with the following ratio of components in wt %: epoxy resin UP-610 17.6-24.7, aliphatic epoxy resin DEG-1 3.1-4.4, aromatic amine UP-0638 4.2-6.0, aramid type fibre reinforcement 65-75.
EFFECT: composite material has better elastic and strength properties, particularly Young's modulus of elasticity of 123 GPa and ultimate tensile stress of 2,57 GPa.
1 cl, 2 tbl, 3 ex
The invention relates to composite materials based on epoxy resin and a fibrous filler (harness) aramid type that can be used in the construction of aircraft.
Known composite material brand OP-MS/17-N (Passport reg. No. 0553-35 from 04.09.97)containing as filler harness "Armos" aramid type and binder up-2217. The composition of the binder up-2217, wt.%:
|resin pack-610 (TU 2225-546-00203521-98||40|
|or THE 2225-606-11131395-2003)|
|resin deg-1 (TU 2225-027-00203306-97||to 6.67|
|or THE 2220-527-00203521-98)|
|resin ED-22 (GOST 10587)||20|
|hardener Diameter-X (TU 6-14-980-84)||33,33|
For more information about the components presented in table 1.
The disadvantages of this material include the level uprugoopticheskii properties of a composite material, the complexity of the composition of the binder and environmental hazard due to the high content of the curing agent is probably carcinogenic substance.
Technical C is the summer residence of the invention is to improve uprugoopticheskii properties of composite material. The technical result is achieved by using a new epoxy binder composition, wt.%:
|a mixture of aromatic amines 4,4'-diaminodiphenylmethane and|
|№ p/p||Component||Chemical basis||Regulatory documentation||Hazard class|
|1||Resin pack-610||The condensation products of p-aminophenol and of epichlorohydrin, followed by dehydrochlorination alkali||THE 2225-546-00203521-98, THE 2225-606-1113195-2003||para-aminophenol, 2-epichlorohydrin-2|
|2||Resin deg-1||The condensation product of epichlorohydrin with polyhydric alcohols, followed dihydrochloride the receiving lye||THE 2225-027-00203306-97, THE 2220-527-00203521-98||the epichlorohydrin-2|
|3||Resin ED-22||Epoxy resin (polymer diglycidylether ether)||GOST 10587||the epichlorohydrin-2 toluene-3|
|4||Hardener Diameter-X||Dichlorodiphenylmethane||THE 6-14-980-84||3 probably carcinogenic product|
The binder content, wt.%: 25-35; the content of the fibrous filler aramid type, wt.%: 65-75.
The technical result is achieved by a combination of mechanical and adhesive properties of the new polymer matrix of the above composition, which leads to an increase of the resulting physical and mechanical properties of the composite.
It is known that the characteristic of the molecular structure of the epoxy polymer matrix is the structure of elementary site chemical covalent grid, which is determined by the nature of the source diepoxide. In the most well-known epoxy-amine polymer is trifunctionally site, which consists of two molecules of epoxy resin and one - amine the CTE is the founder with the center node the nitrogen atom
During curing amines, new hydroxyl group and a tertiary nitrogen atom in the centre of the grid.
Aliphatic resin (deg-1, TAG-1 and others) contain a large amount of epoxy (15-30%) groups and have a low viscosity (at 25°C 0.05 To 1 PA), which allows to use them in prescription formulations as the active diluents other epoxy resins which helps to increase the elasticity and impact strength of solidified polymer matrix.
The choice of aromatic amine as the curing agent due to the heat resistance of the resulting polymer (160-200°C). To improve its compatibility with epoxy resins, it is advisable to use low molecular weight epoxy resin (Mcf=350-600) in combination with low viscosity aliphatic. Thus the variation of the molecular structure of epoxy oligomers and their combination among themselves and hardeners can be directed to control the properties of polymer matrix and composites based on them.
Composite material made by the method of "wet winding". In the reactor by sequential mixing of the components is formed of epoxy binder, which is transported into the tub. Through the bath extends harness (roving or cloth)supplied to the mandrel for winding the product.
For measuring the population of physico-mechanical properties of samples of a composite material produced by winding the impregnated tow "Armos" on a special holder. The mandrel was placed in a heat chamber, where were the mode of curing the binder is graded according to the technological scheme:
rise to 85°C free;
aging at 85°C - 6 hours;
rise up to 100°C free;
exposure at 100°C - 2 hours;
rise up to 140°C - free;
aging at 140°C - 2 hours;
rise to 160°C - free;
aging at 160°C - 6 hours;
the cooling thermostat.
After cooling mandrel made eat samples of composite material for subsequent determination of physical-mechanical characteristics - destructive tensile stress and elastic modulus of a composite material according to OST 92-1473-78.
Experimental results the proposed composite material are shown in table 2. For example, for a composition with the following ratio of components, wt.%
|a mixture of aromatic||amines|
|fibrous order the tel aramid type||70|
corresponding values destructive tensile stress at 20°C Is To 2.57 GPA, modulus of elasticity - 123 GPA.
For the received material value destructive tensile stress at 20°C 4.9% higher compared with the equivalent value of the modulus of elasticity is higher by 23%.
Thus, when using a binder of the above new formulation obtained a new composite material that has a higher physical and mechanical characteristics.
|Index||Base case composite material: harness "Armos" + binder up-2217||The proposed composite material|
|Harness "Armos" (75 wt.%) + new epoxy binder||Harness "Armos" (70 wt.%) + new epoxy binder||Harness "Armos" (65 wt.%) + new epoxy binder|
|Ultimate tensile stress tensile 20°C, HPa||2,45||2,56||to 2.57||2,54|
|The module is provosty, HPa||100||120||123||121|
Composite material made by the method of wet winding of the fibrous filler (harness) aramid type and composition, consisting of a mixture of epoxy resin as a polymer matrix and an aromatic amine as a curing agent in the following ratio, wt.%:
|epoxy resin NC-610||17,6-24,7|
|epoxy resin aliphatic deg-1||3,1-4,4|
|aromatic amine UE-0638||4,2-6,0|
|fibrous filler aramid type||65-75|
SUBSTANCE: invention relates to filled polymer compositions used to make electrically insulating friction bearings. The antifriction dielectric composition contains 50-60 wt % fabric with surface density of 180-220 g/m2 made from polyphenylene 1-3-4-oxadiazole thread with thickness of 80-110 tex and 40-50 wt % polymer binder - chlorine-containing polyglycidyl arylene diamine epoxy resin.
EFFECT: composition has good physical and mechanical, tribotechnical and dielectric properties and is characterised by high dimensional stability when used in water.
1 tbl, 10 ex
SUBSTANCE: invention relates to preparation of filled polymer antifriction compositions which used to make friction bearings of impellar blades of adjustable-blade turbines. The composition contains reinforcing fabric made from carbon fibre with average size of crystals on the basal plane of 3.0-6.0 nm and thickness of the packet of basal planes of 1.0-4.0 nm, thermosetting polymer binder based on chlorine-containing polyglycidyl arylene diamine resin and polytetrafluoroethylene inclusions with thickness of 2-4 mm and surface area of 4-9 mm2, total surface area of which makes up 10-30% of the surface area of the composition. The method of preparing the composition includes a step for adding a surface layer of polytetrafluoroethylene inclusions. Longitudinal and transverse 2-4 mm deep grooves are cut on a solid workpiece made from polytetrafluoroethylene. The surface layer of the workpiece with inclusions cut on a lathe is activated through treatment with a sodium naphthalene complex, joined through projections inside with carbon fabric which is saturated with chlorine-containing polyglycidyl arylene diamine resin. After combined pressure moulding, a surface sheet made from polytetrafluoroethylene is cut, leaving inclusions from polytetrafluoroethylene in the surface layer of the composition.
EFFECT: obtaining a composition which with low friction coefficient and low linear wear rate during prolonged use.
5 cl, 4 dwg, 1 tbl, 9 ex
SUBSTANCE: invention relates to a method of obtaining friction polymer materials and can be used in making brake shoes of railway wagons and locomotives, for motor transport, cranes, structural articles in machine building and other articles. The method of producing friction polymer materials involves processing butadiene or butadiene-nitrile rubber on plastification equipment with their subsequent mixture with a vulcanising agent in form of organic peroxides (A) in form of mixtures with powder (B) and solid phenol-formaldehyde resin (C) in ratio A:B:C ranging from 2:96:2 to 8:70:22. Further, a water-soluble epoxy component is added, which is a product of reacting diane resin with glycol and an aliphatic expoxy resin in form of impregnation of an aqueous solution of the resin on fibre filler with subsequent drying at resin content of 4-30% in terms of the dry product. Fine mineral or metal powder is used. The material contains the following in pts. wt: rubber - 100, vulcanising agent - 30-100, saturated fibre material - 20-120.
EFFECT: improved strength characteristics with simultaneous prevention of diffusion penetration of sulphur into the steel surface of touched article, as well as increased labour safety when mixing components on the plastification equipment - rolls, rubber mixers etc.
2 tbl, 1 ex
SUBSTANCE: invention relates to a thermosetting resin composition for protective coating semiconductor devices from the effect of the environment. The composition contains epoxy resin - ED-20, filler, polymerisation catalyst - boron compound and a mixture of mono-, di- and polysulphides of 2-tert-butylphenol having the structure:
in amount of 2.4-4.0% of the mass of the epoxy resin. Proposed also is a method of making a protective coating for semiconductor devices.
EFFECT: invention enables protection of semiconductor articles and microcircuit chips from external effects, including radiation exposure.
2 cl, 2 ex, 2 tbl
SUBSTANCE: invention relates to a solid resin composition for use in powder coating compositions and for making thermosetting resin for impact-resistance powder coating. The composition contains the following: (a) epoxide resin and (b) amphiphilic block-copolymer containing at least one block segment compatible with epoxide resin, and at least one block segment incompatible with epoxide resin; where the incompatible block segment contains at least one polyether structure, provided that the polyether structure in the said incompatible block segment contains at least one or more alkylene oxide monomer links, having at least four carbon atoms; where the compatible block segment contains at least one polyether structure; where the final resin composition is in solid form. Proposed also is a method of preparing a coating composition curable at normal conditions with high content of solid substance, a method of making a coated base and a coated article.
EFFECT: invention improves impact viscosity of epoxide resins.
26 cl, 1 ex, 1 tbl, 2 dwg
SUBSTANCE: proposed is a curable adhesive composition of epoxide resin which contains: (a) epoxide resin; (b) amphiphilic block-copolymer containing at least one block-segment compatible with epoxide resin and at least one block-segment incompatible with epoxide resin; where the incompatible block-segment contains at least one polyether structure provided that, the polyether structure of the said incompatible block-segment contains at least one or more alkylene oxide monomer links containing at least four carbon atoms; where the compatible block-segment contains at least one polyether structure; where the amphiphilic block-copolymer is present in the epoxide resin adhesive composition in such an amount that, when the said epoxide resin adhesive composition solidifies, bonding strength of the obtained hardened epoxide resin adhesive composition increases compared to epoxide resin composition without the said amphiphilic polyether block-copolymer; and (c) at least one hardening agent or hardening catalyst; and (d) a viscosity modifier. The invention also relates to a method of obtaining a curable epoxide resin adhesive composition, and two or more bases joined using the said adhesive composition.
EFFECT: invention improves impact viscosity of epoxide resins.
21 cl, 2 ex, 3 tbl
SUBSTANCE: invention relates to a heat-conducting adhesive composition designed for attaching components in order to dissipate heat from warm components for radio engineering purposes and for cooling heat-loaded components working under impact and vibration loads. The composition contains an epoxide diane resin, butyl cellosolve monoglycidyl ether Laproxide 301, polyoxypropylene triol triglycidyl ether, boron nitride and a low-molecular polyamide resin. The composition additionally contains an ethylenediaminomethylphenol AF-2 hardener. The polyoxypropylene triol triglycidyl ether used is Laproxide 703.
EFFECT: use of the composition increases adhesive shear strength combined with high heat-conductivity.
SUBSTANCE: there is proposed coating composition with high content of solid substance and hardened under normal conditions. The composition contains the following: (a) epoxide resin; (b) amphiphilic block-copolymer containing at least one block-segment compatible with the epoxide resin, and at least one block-segment incompatible with the epoxide resin; where the incompatible block-segment contains at least one polyether structure; where the compatible block-segment contains at least one polyether structure; and (c) sufficient amount of a nitrogen-containing hardening agent for hardening the coating composition at temperature below 60°C. The invention also relates to a method of preparing a coating composition with high content of solid substance and hardened under normal conditions, to a method of making a coated base and a coated object.
EFFECT: invention increases impact viscosity of the coating composition.
23 cl, 1 ex, 2 tbl, 3 dwg
SUBSTANCE: composition contains (a) epoxide resin; and (b) amphiphilic block-copolymer which contains at least one block segment compatible with the said opoxide resin and at least one block segment incompatible with the epoxide resin. The incompatible block segment contains at least one polyether structure, provided that the polyether structure of the said incompatible block segment contains at least one or more monomer units of alkylene oxide which contains at least four carbon atoms. The compatible block segment contains at least one polyether structure. The invention also relates to a method for preparing epoxide resin, a composite and laminated material.
EFFECT: invention increases shock resistance of thermosetting epoxide resins.
28 cl, 14 ex, 3 tbl, 4 dwg
SUBSTANCE: composition contains a cross-linked epoxide resin in amount ranging from approximately 20% to approximately 80% of the mass of the composition; a tri-block copolymer of polystyrene-polybutadiene-polymethylmethacrylate in amount ranging from approximately 1% to approximately 20% of the mass of the composition, with concentration ratio ranging from approximately 1:1:1 to approximately 1:1:1,5; filler material in amount ranging from approximately 0.001% to approximately 65% of the mass of the composition; and a hardener in amount ranging from approximately 0.69% to approximately 15% of the mass of the composition. The invention also relates to an article and a method of protecting the article.
EFFECT: invention increases coating flexibility.
10 cl, 28 ex, 9 tbl, 2 dwg
SUBSTANCE: invention relates to making construction polymer composite materials based on fiber reinforcement made from aramid fibres and polymer binders, which can be used as airtight cladding of honeycomb panels, as well as monolithic components in machine- and ship building and aviation industries. The prepreg contains the following in wt %: epoxy-rubber, phenol-rubber or epoxy-sulfonic binder- 40-60 and aramide filler - sateen, twill or linen weave fabric made from SVM and Rusar fibres with linear density of 14.3 tex and 29.4 tex - 40-60. The article is made from the prepreg through moulding.
EFFECT: prepreg has good elastic and strength properties, in particular flaking strength of 1,1-1,3 N/cm and ultimate flexural strength of 520-560 MPa.
2 cl, 5 ex, 2 tbl
FIELD: paper industry.
SUBSTANCE: roll of polymer paper is installed on unit of paper unwinding 1. Beginning of paper roll is pulled through transport rolls 3, lubricating roll 4, impregnation bath 5, rolling mangles 6, floating roll 7, pulling roll 8, driving roll 9, and fixed on winding unit 10. After stabilisation of device technological parametres paper is pulled through working path of device. Paper is wound from winding unit 1, goes along lubricating roll 4 through bath 5 and enters thermal block 12, where organic dissolvents are removed, and binding coating is polymerised. Paper that has passed through thermal unit with coating goes through a system of pulling rolls and arrives to winding unit 10. Invention makes it possible to produce prepregs from aramid papers of Nomex® and Kevlar® type with various thickness and various thickness of binder coating and its extent of polymerisation.
EFFECT: invention may be used to produce prepregs of aramid papers applied to create light fillers of multilayer aviation panels.
SUBSTANCE: invention refers to the high-strength epoxide composition used for impregnation at production of high-strength glass-, carbon,- organic-, and boron plastics working in the wide temperature range and used in different industrial sectors (machinery construction, shipbuilding, aircraft and space industries, for production of the parts of complicated configuration e.g. thin- and thick-walled casings). The invention refers also to the method for preparation of the said composition including the following components (weight parts): 10-100 - diglycidyl resorcinol ether, 10-100 - product of epichlorohydrin condensation with triphenol, 6-12 - oligoether cyclocarbonates with mass ratio of cyclocarbonate groups in the range from 18 to 29, 28-50 - curing agent (primary aromatic amine), 0.5-2.5 - curing agent (tertiary amine), 0.25-1.25 - mixture of carbon and silicate nanomaterials. The mass ratio of diglycidyl resorcinol ether to product of epichlorohydrin condensation with triphenol is in the range from 1 : 9 to 9 : 1. Metaphenylen diamine or 4,4'-diaminodiphenylmethane or their eutectic mixtures in ratio from 40 : 60 to 60 : 40 are used as primary aromatic amine. Mono-, di and trimethylsubstituted pyridine or monovinylsubstituted pyridine are used as tertiary aromatic amine. The carbon nanomaterial is fullerene C2n, wherein n is no less than 30, the silicate nanomaterial is organobentonite, the fullerene : organobentonite ratio is in the range from 1 : 3 to 3 : 1. The method of composition preparation consists in stirring of nanomaterials mixture with oligoether cyclocarbonates by ultrasonic action at frequency 22-44 kHz during 30-45 min. Then the obtained suspension is mixed with beforehand prepared mixture of diglycidyl resorcinol ether and product of epichlorohydrin condensation with triphenol. After that the curing agent in the form of aromatic primary and tertiary amine mixture is added. The ready composition is cured in step mode with maximal curing temperature 155°C.
EFFECT: invention allows obtaining of the composition with high physical, mechanical and dissipative properties.
2 cl, 2 tbl, 6 ex
SUBSTANCE: invention relates to dressing compositions based on mineral fibre, containing epoxy resin of glycidyl ether type, amino-containing hardener and accelerator-imidazol, imidazoline, their mixture.
EFFECT: improved mechanical properties of materials after aging.
17 cl, 1 tbl, 1 ex
SUBSTANCE: present invention pertains to machine building, and particularly to fibre prepreg, used for making objects for various purposes from wear-proof polymer composite material. The fibre prepreg is made in form of a fibre base from fusible, as well as glass or carbon fibres of infusible threads. The fibre base is made from a complex thread, weaved from fusible and infusible fibre. The fusible fibre in the complex thread is ultrahigh-molecular polyethylene, or polypropylene, or polyethylene caproamide or polyethyelene terephthalate. The infusible fibre in the complex thread is polyoxadiazole fibre and cotton fibre, or polyparaphenylene terephthalamide fibre or polymetaphenylene terephthalamide fibre. The prepreg is made in form of a sheet (fabric), ribbon, linen, non-woven material or cut thread. Part of the fusible fibre in the complex thread can be substituted with powder or granules of fusible material.
EFFECT: design of a fibre prepreg, use of which increases the longevity of different components, made from the prepreg.
9 cl, 3 tbl
FIELD: technological processes.
SUBSTANCE: method includes application of adhesive strips in longitudinal direction on initial material cloth, its cutting into stocks in direction that is perpendicular to adhesive strips, honeycomb packet assembly from stocks by means of packing with displacement of every stock in relation to adhesive strips adjacent by half of pitch, adhesion of honeycomb packet stocks according to preset mode, stretching of honeycomb packet and its impregnation with polymer binder, drying of impregnated honeycomb packet on air with further hardening of polymer binder, at that as initial material glass tissue is used, after honeycomb packet impregnation with polymer binder its excess is removed by free flowing to the moment of sharp reduction of flowing binder amount, stretched honeycomb packet is turned over by 180°C, and surplus of polymer binder flows into its cells from the top end of honeycomb packet for the time equal to 1/3 of the time spent for previous flowing, once again stretched honeycomb packet is turned over by 180°C, and surplus of polymer binder flows from the other end of honeycomb packet in its cells for 1 minute, stretched packet is turned over by 90°C, while channels of cells are located horizontally, and drying of impregnated honeycomb packet is performed for at least 3 hours at room temperature by means of stretched honeycomb packet cells blowing with organised air flow directed to exhaust ventilation.
EFFECT: method provides high interlayer strength and eliminates exfoliation in adhesive strips; uniform strength and density in the whole volume of honeycomb and provision of air drying process intensity.
1 tbl, 8 ex
SUBSTANCE: binding agent includes components at the following ratio, weight parts: epoxy diane resin or its mix with diglycidyl diethyleneglycol ether 18-50, polyfunctional epoxy resin 18-60, bromine-containing epoxy diane resin 18-34, bis-N,N-(dimethylcarbamido)diphenylmetane as solidifier 3-6, alcohol and acetone mix as organic solvent 70-105. Bromine-containing epoxy diane resin is an oligomer product of tetrabromdiphenylolpropane and epychlorhydrine condensation in 600-1500 mol mass amount in the form of diglycidyl tetrabromdiphenylolpropane ether mix with its dimmer and trimer at the component ratio of (3-4):1:(0.2-0.8) or diglycidyl tetrabromdiphenylolpropane ether mix with its dimmer, trimer and chlorhydrine ether at the component ratio of (3-4):1:(0.2-0.8):(0.5-0.6). Prepreg includes components at the following ratio, wt %: epoxy binding agent described above 30.0-42.0, and fiber filler 58.0-70.0. An article is produced by prepreg modelling.
EFFECT: increased stability of binding agent solutions and improved durability properties of composition materials and articles made of them.
3 cl, 3 tbl, 4 ex
SUBSTANCE: first version of invention claims composition of the following component ratio, wt %: N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dichlordiphenylmethane 24.8÷42.1 and triglycidyl-aminophenol as polyfunctional epoxy resins 11.5÷25.8, polycrystalline powder of N,N'-hexamethylenebismaleimide as bismaleimide 25.8÷41.3, polycrystalline powder of 4,4'-diaminodiphenylsulfone as solidifier 17.4÷22.6. Second version of invention claims composition of the following component ratio, wt %: N,N,N',N'-tetraglycidyl-4,4'-diamino-3,3'-dichlordiphenylmethane 21.6÷49.5 and triglycidyl bisphenol-A ether as polyfunctional epoxy resins 16.1÷32.4, polycrystalline powder of N,N'-hexamethylenebismaleimide as bismaleimide 3.5÷27.0, polycrystalline powder of 4,4'-diaminodiphenylsulfone as solidifier 19.0÷25.8. Method of obtaining the claimed compositions involves addition of polycrystalline 4,4'-diaminodiphenylsulfone powder to homogenous polyfunctional epoxy resin melt during stirring at 120÷130°C in minimum time sufficient for its complete dissolution. Then the temperature of obtained homogenous melt is lowered to 90÷100°C. By further stirring polycrystalline powder of N,N'-hexamethylenebismaleimide is added to the melt in minimum time sufficient for its complete dissolution. Prepreg includes components at the following ratio, wt %: the claimed epoxybismaleimide binding agent 20-48 and fiber filler 52-80. An article is produced by the claimed prepreg modelling.
EFFECT: improved durability of binding agent and increased vitrifying temperature and flexural strength of article.
6 cl, 2 tbl, 10 ex
FIELD: technological processes.
SUBSTANCE: glue strips are applied with preset pitch onto glass tissue cloth in longitudinal direction, then they are dried, and glass tissue with applied glue strips is cut into preforms in direction that is perpendicular to glue strips, honeycomb packet is assembled from prepared preforms by laying with displacement of every preform in respect to glue strips that are adjacent by half of pitch, preforms of honeycomb packet are glued at preset temperature and pressure, and honeycomb unit is produced by means of honeycomb packet extension, then prepared extended honeycomb unit is soaked with polymer binder, it is hardened in accordance with preset mode, at that as glass tissue thin glass tissue is used on the basis of fibres made of alumina-borosilicate alkali-free glass of "А-5Пx90" or "А-4Пx90" type, for glue strips phenol-polyvinyl-acetal glue is used of BF-2 type with viscosity of 45 by viscosity gage VZ-246, gluing of honeycomb packet preforms is carried out under vacuum of 0.12-0.16 kgf/cm2 according to temperature-time mode: heating up to temperature of 80°C with further pause of 30 minutes, heating up to temperature of 150°C with further pause of 60 minutes, heating up to temperature of 170°C with further pause of 120 minutes, as polymer binder for soaking, bakelite lacquer is used of LBS-1 brand with viscosity of 15 by viscosity gage VZ-246, hardening of honeycomb unit soaked with polymer binder is carried out in accordance with the following mode: heating up to temperature of 100°C with further pause of 30 minutes, heating up to temperature of 150°C with further pause of 90 minutes, heating up to temperature of 170°C with further pause of 120 minutes.
EFFECT: provision of honeycomb filler compression strength; expansion of assortment of manufactured honeycomb filler and increase of manufacturability.
1 tbl, 6 ex
FIELD: technological processes.
SUBSTANCE: method includes the following: viscose or polyacrylonitrile technical thread is soaked with the mixture of epoxy resin ED-20 and hardener polyethylene polyamine with mass ratio 9:1. Then bundle is formed out of separately soaked technical threads with the number of threads of 100-140 and is thermally treated at the temperature of 30-70°C. At the same time the shaped bundle is exposed to ultraviolet radiation with power of 0.70-0.80 Watt/m3 at the wave length of λ=253.7 for 8-12 minutes, and then hardened.
EFFECT: increases breaking stress during static bending of materials with polyacrylonitrile technical thread.
SUBSTANCE: invention relates to selectively removable intermediate coating compositions, containing at least one polyamide with a terminal amino group, in which average molecular weight of the polyamide with the terminal amino group ranges from 500 Da to 100000 Da. The invention also relates to a multilayer coat containing a first coat (basic coat); a second coat (outer coat); an intermediate coat between the first and second coats, in which the intermediate coat contains at least one polyamide with a terminal amino group, which is used to coat surfaces of aircraft and spacecraft.
EFFECT: obtaining a coating composition for facilitating selective removal of the outer and intermediate coats by washing off without removing the basic coat.
46 cl, 4 ex, 1 tbl