Expandable polyamide composition and its foam

FIELD: chemistry.

SUBSTANCE: invention concerns expandable polyamide composition consisting basically of: (A) compound with at least one isocyanate group, possible blocked one, (B) polyamide, and (C) compound with at least one acid group, preferrably carboxyl one. The invention also concerns production of polyamide foam from the said composition and the foam produced in this process. The said process allows obtaining foam directly from the said composition, i.e. without addition of any extra compounds, as well as foaming reaction control. Moreover, according to the invention, this foam has regular cell distribution conforming to the closed type and can be applied in various fields, e.g. in thermal or sound insulation and saddlery.

EFFECT: obtainment of foams of various types and properties.

30 cl, 1 tbl, 7 ex, 1 dwg

 

The present invention relates to capable of foaming polyamide compositions and from the polyamide foam, as well as to a method for the specified foam.

Synthetic foam are different applications, such as thermal or buzzer isolation, saddlery manufacture.

Mainly, there are two types of foam: structured foam and unstructured foam.

Structured foam is a rigid foam, consisting of a core of low density and shell whose density is close to the density of the polymer forming the matrix. These foams can be used as a degreasing materials, for example, in the aviation and automotive industries.

Flat foam can be flexible or rigid. Rigid foam is used in the field of thermal insulation (gas contained in the cells, acts as an insulator). Due to its ability to compressibility and depreciation flexible foam used for furniture making and saddlery manufacture, and due to its ease of packaging, as well as in the field of sound insulation (foam having open pores that can absorb certain frequencies).

There are various methods for producing foams from thermoplastic polymer, such as foam polystyrene, polyvinylchloride, polyethylene, polypropylene, etc.

Known the Yong way of injecting gas under pressure into the polymer in the melt.

There is also known a method of inclusion of pore - thermally unstable fillers in the polymer melt, which releases the gas in the process of decomposition. Sometimes the method is difficult to control, so formed, the cells may be of irregular shape.

In the polymer melt can also add soluble therein in connection with this foam is produced by evaporation of these compounds.

Finally, the foam can be obtained by using a chemical reaction accompanied by the evolution of gas, such as carbon dioxide. Examples are polyurethane foam obtained by the reaction between isocyanates, polyols and water, which lead to the formation of polyurethane with liberation of carbon dioxide.

Polyamide foam can also be obtained by chemical means in the presence of isocyanates and lactams, as well as grounds for acceleration of anionic polymerization (FR 1547241).

In the present invention claimed another chemical way to obtain a polyamide foams capable of expanding compositions comprising a compound containing at least one isocyanate group, one polyamide and one compound containing at least one acid group. A composition and foam is simple, foam receive in situ without the necessity of introducing external connections and directly from HDMI is tion. The method of producing foam allows, in particular, to control the foaming reaction. This method is flexible: really, foam and various diverse types and properties can be easily obtained by the above method, in particular, by appropriately selecting the type and characteristics of the polyamide composition.

The first object of the present invention is capable of foaming composition comprising at least the following connections:

A: a compound containing at least one isocyanate group;

In: polyamide;

From: a compound containing at least one acid group, preferably carboxyl.

The second object of the present invention is a method of obtaining a polyamide foam capable of foaming of the composition described above, comprising at least the following stages:

a) the composition is heated to a temperature of at least 80°

b) stabilize the obtained honeycomb structure. Finally, in the present invention claimed polyamide foam obtained by the method described above.

Under acidic group understand any acid group, which by reaction with the isocyanate group capable of releasing a gas, usually carbon dioxide; as an example, carboxyl, phosphate, sulfonic acids of the s group, etc. However, the carboxylic acid groups are preferred. Under acidic group see also group derived from an acid group such as acid anhydride, carboxylic acid, ester group, etc. Listed derivatives group selects gas either directly, usually carbon dioxide by reaction with isocyanate group at a high temperature, or indirectly after the reaction derivatives of groups with a connection, regenerating acid group; as an example, the derived group, which may lead indirectly to greenhouse gas emissions, we can consider the group of carboxylic acid or anhydride of carboxylic acid, of which acid carboxyl group can be obtained by reaction with water.

Connection With the composition contains at least one acid group. Polyamide connections usually also contains carboxylic acid groups; these acid groups can be placed at the ends of the polyamide and/or distributed along the polyamide chain. Acid groups along the polyamide chains can be introduced into the polycondensation reaction using co monomer, such as, for example, iminodiacetate, or, for example, by functionalization of amide bonds, in particular, by reaction with acid aldehyde.

Connection And maybe also with erati acid group, in particular carboxyl groups.

These carboxylic acid groups capable to react with isocyanate groups of the compounds And on the following reaction:

In General capable of foaming the composition according to the present invention contains an appropriate amount of acid groups and isocyanate groups, which are selected so as to stand out gas, in particular carbon dioxide, and to obtain from capable of foaming composition a foam of the desired density.

The acid groups can be introduced only with the connection or with polyamide, or only with connection A, and any two of the above compounds a, b and C or three compounds a, b and C.

Case where the acid group injected only with polyamide, corresponds to a specific implementation method of the present invention, in which the connection is polyamide Century

The case when the acid group is introduced only with the connection And meets other specific implementation method of the present invention, in which the connection is the connection A.

The polyamide In the present invention is a polyamide type polyamides, obtained by polycondensation of dicarboxylic acids and diamines, or type polyamides, obtained policed what Nazia of lactams and/or amino acids. The polyamide In the present invention may be a mixture of polyamides of different types and/or of the same type, or copolymers prepared from different monomers corresponding to one type and/or different types of polyamide.

In accordance with the preferred method of implementing the present invention, the number of moles of acid groups of the polyamide exceeds the number of moles of amino groups, and in this case usually speak of the polyamide having an excess of acid end groups.

The polyamide In the present invention may be an oligomer. Brednikova molecular weight of the polyamide of the present invention is preferably more than or equal to 1000 g/mol, preferably more than or equal to 3000 g/mol.

As an example, polyamide corresponding to the present invention may include a polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, polyamide 4,6; 6,10; 6,12; 12,12; 6,36; polyaromatics polyamides, polyphthalamide obtained from terephthalic and/or isophthalic acid, such as the polyamide sold under the trade name AMODEL, their copolymers and mixtures.

In accordance with the preferred method of implementing the present invention, the polyamide selected from polyamide 6, polyamide 6,6, their blends and their copolymers.

According to a separate embodiment of the present invention the polyamide according to the invention I which is a linear polyamide.

In accordance with another separate embodiment of the present invention, the polyamide according to the invention contains macromolecular chains of star-shaped or H-shaped form and, if necessary, linear macromolecular chains. Polymers containing macromolecular chains of star-shaped or H-shaped, as described, for example, in patents France 2743077, 2779730, USA 5959069, European applications 0632703, 0682057 and 0832149.

In accordance with another separate embodiment of the present invention the polyamide of the present invention is a copolymer of polyamide, with a statistical tree-like structure. These copolymers of polyamide statistical tree structure, and method of production thereof are described, in particular, in the international patent application 99/03909.

The polyamide of the present invention may also be a composition comprising one linear polyamide and one polyamide with star-shaped, H-shaped, and/or tree structure, which is described previously.

The polyamide of the present invention may also be a composition comprising one hyperbranched copolymer nylon type polyamide copolymers described in the international patent application WO 00/68298.

The polyamide may contain other groups such as ester groups, and/or group is Icewine, and/or carbonates, and/or a simple ester, etc.

The compound a of the present invention is a compound containing at least one isocyanate group; it could be a mixture of compounds containing at least one isocyanate group.

In accordance with the preferred method of implementing the present invention, the compound a is a polyisocyanate.

Under the polyisocyanate understand compound containing at least two isocyanate groups.

Polyisocyanate of the present invention is preferably a polyisocyanate following formula (I):

Y-(-N=C=O)n

where Y is a polyvalent substituted or unsubstituted aromatic, aliphatic, cycloaliphatic or heterocyclic group containing or not containing heteroatoms, and n is at least equal to 1. Examples of the corresponding isocyanates are isophoronediisocyanate, 1,3 - and 1,4-cyclohexanedimethanol, 1,2-atlantaatlanta, 1,4-tetramethyldisilane, 1,6-hexamethylenediisocyanate, 2,2,4 - and 2,4,4-trimethyl-1,6-hexamethylenediisocyanate, 1,12-dodecanesulfonate, alpha,alpha'-diisocyanatobutane ether, 1,3-cyclobutadiene, 2,2 - and 2,6-diisocyanato-1-methylcyclohexane, 2,5 - and 3,5-bis(isocyanatomethyl)-8-methyl-1,4-metadatarepository, 1,5-, 2,5-, 1,6 - and 2,6-bis(isocyanatomethyl)-4,7-metareligion, 1,5-, 2,5 - is 2,6-bis(isocyanate)-4,7-metareligion, 2,4'- and 4,4'-dicyclohexylmethane, 2,4 - and 2,6-hexahydrotriazine, perhydro-2,4'- and 4,4'-diphenylmethanediisocyanate, alpha,alpha'-diisocyanate-1,4-diethylbenzene, 1,3 - and 1,4-delete the entry, 4,4'-diisocyanate, 4,4'-diisocyanate-3,3'-dichlorobiphenyl, 4,4'-diisocyanate-3,3'-dimethoxybiphenyl, 4,4'-diisocyanate-3,3'-dimethylbiphenyl, 4,4'-diisocyanate-3,3'-diphenylmethane, 2,4'- and 4,4'-diisocyanatobutane, naftilan-1,5-diisocyanate, 2,4 - and 2,6-colorvision, N,N'-(4,4'-dimethyl-3,3'-diisocyanatomethyl)uretdione, m-killadysert, dicyclohexylmethane, tetramethyldisilazane, 2,4,4'-triisocyanate ether, 4,4',4"-triisocyanate, and analogs and mixtures. As examples of such oligomers of MDI can cause the trimeric isocyanurate (HDI-trimer), such as Tolonate HDT® the company Rhodia, biuret, such as tolonate HDB® the company RHODIA. Other examples of oligomers isocyanate is an aliphatic isocyanate oligomers, such as dimer or trimer of isophorondiisocyanate, asymmetric trimer of hexamethylenediisocyanate, as well as derivatives of hexamethylenediisocyanate high functionality and low viscosity, as well as dimers and trimers norbornadiene.

In accordance with the preferred method of implementing the present invention, the polyisocyanate is a mixture of poliisi analnyj compounds with an average functionality which is in the range from 2 to 8 (including borders), preferably in the range from 3 to 7 (including borders). Functionality is defined as the number of isocyanate groups introduced each of the constituent molecules of the mixture.

As an example, mixtures of MDI can cause the trimeric isocyanurate, such as standard trimer of hexamethylenediisocyanate (HDT), a trimer of isophorondiisocyanate (IPDT), the average functionality of which is approximately 3.5.

You can also use the derivatives of polyisocyanates of isocyanurate of toluene diisocyanate (TDI) or diphenylsilane methane (MDI).

In accordance with another preferred method of implementing the present invention, the polyisocyanate is a diisocyanate, i.e., the polyisocyanate containing two isocyanate groups, or triisocyanate, i.e. the polyisocyanate containing three isocyanate groups. Preferably the polyisocyanate is isocyanurate.

Preferably the compound containing at least one isocyanate group, differs from the prepolymer or polymer.

According to a separate embodiment of the present invention isocyanate group connection And a fully or partially protected by a protective group that is generally associated with the isocyanate group of the covalent bond. Protected polyisocyanate by N. the present invention is preferably a polyisocyanate following formula (II):

Y-(-NH-C(=O)-B)n

where In represents the balance of the protective group NR, Y and n have the same meaning as in the formula (I) above.

As an example, protective groups in HV corresponding to the present invention may include a lactam, such as caprolactam or dodecalactam; oximes such as 2-butanonoxime, pyrovatex, acetoxy or benzophenone; heterocyclic possibly substituted compounds such as derivatives of pyrazole, triazole, imidazole, benzotriazole or their alkyl derivatives, such as dimethylpyrazol, methylpyrazole, Dimitry triazole, 2-ethyl or propylimidazol; alcohols or phenols and their derivatives, such as tertbutanol, methanol, ethanol, phenol, para - or ortho-hydroxybenzoic acid or the complexity (cyclo)alkyl esters, diallylmalonate, hydroxamic acids, etc.

A separate option protection isocyanate groups is in the case areidentical, which is that the isocyanate group protects itself.

Isocyanate groups can also be protected N-acylated form of exposure to isocyanate groups on the amide group, which may be a polyamide groups.

In accordance with the present invention it is possible to use a mixture of protective groups.

Protected polyisocyanates are liquid compounds or solid compositions. About is a rule, these compounds do not contain solvents.

Protective groups of the present invention are preferably a lactam and even more preferably caprolactam.

Polyisocyanate compounds can contain other groups, such as kochevinova group, and/or biuret, and/or carbamate and/or alohanet, and/or ester groups and/or carbonate group and/or a simple ester.

In accordance with the preferred method of implementation of the present invention the temperature of the "remove protection" from isocyanate groups of the compound, greater than or equal to the melting point or softening polyamide Century In the framework of the present invention the temperature of the "remove protection" isocyanate groups of the compounds And represents the temperature at which to observe the cleavage of the covalent bond between the protective group and isocyanate group, and above which the isocyanate group is again free and reactive. Temperature "remove protection" isocyanate groups is changed, in particular, depending on the type of the protective group. Thus, the choice of protective groups can be selected in accordance with, for example, the melting point of the polyamide selected for this composition. The softening temperature of the polyamide is a temperature above which the polyamide is deformed, if it take effect.

Protection of cyanotic groups of compounds And is usually carried out before obtaining the compositions of the present invention. However, it can also be done while obtaining compositions of the present invention, for example, by introducing a protective group in the presence of components of the composition.

In the framework of the present invention under the isocyanate group connections And understand how isocyanate group protected by a protective group, and unprotected isocyanate groups. For example, when talking about the number of moles of isocyanate groups of the compounds And, if the specified group protected by a protective group or different protective groups, then we are talking about the number of mole of the protected isocyanate groups.

Compound containing at least an acid group is preferably policestate, i.e. a compound containing at least two acid groups. It is possible to use mixtures of different compounds C.

The connection can also be a compound containing an acid group and another group capable of interacting with carboxyl or amino group of a polyamide; as an example, a reactive group can also result in primary or secondary amino groups, alcohols, sulfhydryl etc. as an example of such a connection can lead to citric acid. Preferred reactive groups are primary or secondary amino group.

The connection to the present is in the invention is preferably a dicarboxylic acid. As examples of dicarboxylic acids can lead adipic acid, dodecandioic acid, terephthalic acid.

Capable of foaming composition according to the invention may also contain in addition to the compounds a, b and C a pore-forming agents that will enhance foaming at the time of receipt of foam from this composition. Such pore-forming agents known to experts.

Capable of foaming composition according to the invention may also contain other additives that are useful for subsequent receipt of the foam, such as surfactants, seed, such as talc, plasticizers, etc. These additives known in the art.

The composition may also contain reinforcing fillers such as fiberglass matting compounds such as titanium dioxide or zinc sulfide, pigments, dyes, protective additives from the action of heat or light, bioactive agents, agents, preventing pollution, antistatic agents, flame retardant agents, loading, high or low density, etc. the list is not limited.

To obtain the compositions of the present invention containing the compounds a, b and C, may be used any method of obtaining a composition known to the specialist. For example, it is possible to prepare a homogeneous mixture of powders of different connection of the clusters. You can also type connections a and C in the polyamide In the molten state. The mixture can be prepared, for example, in the device for the extrusion. The polyamide may also be in the form of granules that cover the connections a and C. Another method of obtaining a composition in accordance with the present invention is sagadevan different connections.

If a song receives, for example, using the device for the extrusion, it can then take the form of granules. These granules can then be used in the form in which they are received, or crushed before getting the foam to the powder of the desired particle size distribution capable of expanding composition. Granulometric composition in powder form is preferably less than or equal to 1 mm, preferably less than or equal to 500 microns.

The composition of the present invention may also have, or buy the liquid form or gel form, for example, using any method known to the expert.

If isocyanate group connection And protected by a protective group, then the temperature in obtaining the composition is preferably less than the temperature "remove protection" isocyanate groups.

The second object of the present invention relates to a method for producing a polyamide foam capable of expansion of the composition, which is previously painted, including at least the following stages:

a) the composition is heated to a temperature of at least 80°C;

b) stabilize the obtained honeycomb structure.

The temperature of stage (a) must be sufficient to allow the reaction between isocyanate groups and carboxylic acid groups in the composition, and exits gas, usually carbon dioxide, and the formation of cellular structure. Temperature and reaction kinetics of decarboxylation depend on the type of the various components of the foam, i.e. compounds a, b and C, and from the presence or absence of catalysts. Usually this temperature is at least 80°C.

In accordance with a separate means of implementing the present invention, the temperature during stage (a) exceeds the melting point or softening polyamide Century

Stage a) is usually carried out in the molten state. During this stage you can use the device for the extrusion process.

The duration of stage a) is changed depending on the device used. During this stage, you can use the catalyst or mixture of catalysts.

The catalyst can, for example, be used to accelerate the removal rate protection or temperature reduction removal protection isocyanate groups of the compound A. as an example, the catalyst can lead derivatives of metals, such as tin derivatives (such as dibutyltindilaurate SN), zinc (such as octoate zinc, bismuth, tertiary amines, such as diazabicyclo (DABCO), diazabicyclo (DBU). To accelerate the reaction of decarboxylation you can use another catalyst, such as the anhydride carbamino acid and the acid obtained by the interaction of the acid group with the isocyanate group; as an example tertiary amines, such as diazabicyclo (DABCO), diazabicyclo (DBU), triethylamine.

A composition of the present invention and receiving foam from the specified composition can be carried out simultaneously. Receiving can be done in similar reactors, such as a device for the extrusion process.

If the isocyanate groups of compounds And capable of expanding compositions protected, the temperature of stage a) is greater than or equal to the temperature of the "remove protection" isocyanate groups of compound A.

Pore-forming agents, and surfactants, seed, such as talc, plasticizers, etc. can be added during stage (a).

During stage a) can also enter other compounds, in particular reinforcing fillers such as fiberglass matting compounds such as titanium dioxide or zinc sulfide, pigments, dyes, substances that protect against those actions the temperature or light, bioactive agents, agents, preventing pollution, antistatic agents, flame retardant agents, etc. the list is not limited.

Stage b) stabilize the cellular structure can be realized, for example, chemically - curing polyamide and/or physical means, for example by cooling to a temperature less than or equal to the temperature of stekloobrazovaniya or melting point of the polyamide. The stitching of the polyamide can be done using cross-linking agents known to the specialist. They are usually compounds containing at least two groups capable of interacting with the acid and/or amino groups of the polyamide. Usually these groups contain at least three reactive groups. As cross-linking agents can lead to carbonville, such as carbonvision, isoxazine, bisoxazoline. These crosslinking agents is preferably introduced in the process of getting ready to expand the composition.

The obtained foam structure may be in the form of granules, which can then be melt or not to melt, or it can take the form, for example, by molding.

Finally, the present invention relates to polyamide foams obtained according to the method described previously. Foam obtained by a specified method, preferably have a density less than or RA is ing 0.5 g/cm 3preferably less than or equal to 0.3 g/cm3.

Further details and advantages of the present invention will become clearer from the examples, which are given below as an explanation.

EXAMPLES

Used connections

Connection B1: a copolymer of polyamide 6/6,6 (60/40)with an excess of acid end groups (GTC=480 mEq/kg), with a relative viscosity, measured in 90%formic acid at 25°equal to 33 ml/year

Compound B2: a copolymer of polyamide 6/6,6 (60/40), with a relative viscosity, measured in 90%formic acid at 25°With 120 ml/year

Compound B3: copolymer of polyamide 6/6,6 (60/40), with a relative viscosity, measured in 90%formic acid at 25°equal to 140 ml/year

Compound B4: copolymer of polyamide 6/6,6 (60/40)with an excess of acid end groups (GTC=1200 mEq/kg).

Connection A1: a trimer of isophorone diisocyanate (IPDT), isocyanate group is protected with a ε-caprolactam, having a titer of isocyanate groups 3200 mEq/kg

The connection A2: a mixture of isophorone diisocyanate (IPDI) trimer of isophorone diisocyanate (IPDT), isocyanate group is protected with a ε-caprolactam, manufactured by Bayer under the trade name Crelan LS2256®.

Connection D1: talc (magnesium silicate), produced by the company Luzenac Europe under the trade name Mistron Vapor RP6®with granulometric composition, equal to 7 μm.

Connection D2: silicon dioxide manufactured by the company Rhodia under the trade name Tixosil 365® and with an average grain size equal to 3.5 μm.

Connection: adipic acid, produced by the company Rhodia.

The resulting compositions are detailed in table. The proportions are in percent by weight of the composition.

Table
ConnectionComposition EComposition FComposition GComposition HComposition JComposition K
B185,8-----
B2-83,3----
B3--83,358,657,157,1
B4---26,326,326,3
A112,912,912,915,115,1-
A2-----15,1
D11,31,51,5---
D2----1,51,5
C-2,42,4---

Example 1

Composition E is obtained by mixing the various compounds in a single screw BRABENDER extruder having a ratio of length/diameter equal to 20. The extrusion conditions are as follows:

- Temperature: 150-175-175-175°

- Output: 2 kg/h

Composition after extrusion is cooled in water to room temperature. Its density is 1.1. The composition of the roughly pulverized to obtain a grain size of 1-2 mm

3 g of the indicated composition is placed in a mold made of Pyrex, pre-coated with the composition, to facilitate removal from the mold. The form is heated to a temperature of 190°C for 30 minutes in the oven with circular heating. Similarly receive a sample of rigid polyamide foam with a density of 0.25. The distribution of cells corresponds to the private type. The cell size varies from 0.1 to 1 mm in diameter.

For information: if in example 1 the composition E replace only the connection A1, the density of the obtained sample is 1.1.

Example 2

10 g HDMI is tion E, described in example 1 (particle size 1-2 mm), subjected to cryogenic grinding to obtain a powder with an average grain size of 300 μm. 3 g of the indicated composition is placed in a mold made of Pyrex, pre-coated with the composition, to facilitate removal from the mold. The form is heated to a temperature of 190°C for 30 minutes in the oven with circular heating. Similarly receive a sample of rigid polyamide foam with a density of 0.2. The distribution of cells corresponds to the private type, and it is quite regular. The cell size varies from 0.1 to 0.2 mm in diameter.

Example 3

Mix the various connections compositions F to powder form, and then the resulting mixture is subjected to cryogenic grinding to obtain a powder with a particle size less than 300 microns. Homogenization is carried out in the process of grinding.

Next, 3 g of the indicated composition is placed in a mold made of Pyrex, pre-coated with the composition, to facilitate removal from the mold. The form is heated to a temperature of 190°C for 30 minutes in the oven with circular heating. Likewise get a sample of a semi-rigid polyamide foam with a density of 0.2. The distribution of cells corresponds to the private type, and it is quite regular. The cell size varies from 0.1 to 0.2 mm in diameter.

Example 4

With eshivot different compound compositions F to powder form, then the mixture is subjected to cryogenic grinding to obtain a powder with a particle size less than 300 microns. Homogenization is carried out in the process of grinding.

Next, 3 g of the indicated composition is placed in a mold made of Pyrex, pre-coated with the composition, to facilitate removal from the mold. The form is heated to a temperature of 190°C for 40 minutes in the oven with circular heating. Likewise get a sample of a semi-rigid polyamide foam with a density of 0.15. The distribution of cells corresponds to the private type, and it is quite regular. The cell size varies from 0.1 to 0.2 mm in diameter.

Example 5

Mix the various connections compositions N to powder form, and then the resulting mixture is subjected to cryogenic grinding to obtain a powder with a particle size less than 300 microns. Homogenization is carried out in the process of grinding.

Next, 3 g of the indicated composition is placed in a mold made of Pyrex, pre-coated with the composition, to facilitate removal from the mold. The form is heated to a temperature of 190°C for 40 minutes in the oven with circular heating. Similarly receive a sample of the polyamide foam with a density of 0.25. The distribution of cells corresponds to the private type, and it is regular. The cell size varies from 0.1 to 0.2 mm in diameter.

The young's modulus by the scientists of the sample is measured on 4 consecutive cylindrical samples with a diameter of 26.5 mm and a thickness of 15.8 mm The measurement is performed using the setup INSTRON 1185 under the following conditions:

Temperature: 23°C;

Relative humidity: 50%;

Movement rate: 20 mm/min

Using this setup gain curve according to the voltage from the strain.

The drawing shows a curve of stress-strain corresponding to the sample composition N.

The average value of the measured module $ 43.4 MPa.

Example 6

Composition J is obtained by mixing the various compounds in the mixer BUSS 46, equipped with knives submersible type. The conditions of extrusion following:

- Temperature: 175-170-160-155-155-140°C;

- Output: 9 kg/hour.

In this way receive the balls polyamide with a diameter of 1.5 mm, and ready foaming". Furthermore, these balls are served in the injection molding machine Billion Stabilog equipped with a "flat" form with a size of 85×85×5 mm with direct Central injection. The temperature profile for the heating elements is as follows: the feed area 165°C-165°S-190°C. the Temperature in the nozzle support level 240°C.

Get a plate with a density of 0.45 (including the shell).

Example 7

Composition To obtain a mixture of compounds in the mixer BUSS 46, equipped with knives submersible type. The conditions of extrusion following:

- Temperature: 175-170-160-155-155-140°C;

- Output: 9 kg/hour.

In this way receive the balls polyamide with a diameter of 1.5 mm, and ready foaming". Furthermore, these balls are served in the injection molding machine Billion Stabilog equipped with a "flat" form with a size of 85×85×5 mm with direct Central injection. The temperature profile for the heating elements is as follows: the feed area 165°C-165°S-190°C. the Temperature in the nozzle support level 240°C.

Get a plate with a density of 0.45 (including the shell).

1. Capable of foaming polyamide composition essentially consisting of the following compounds:

A: a compound containing at least one isocyanate group, possibly protected: polyamide

From: a compound containing at least one acid group, preferably a carboxyl group.

2. The composition according to claim 1, characterized in that the polyamide is In the oligomer or polymer with srednetsenovoj molecular weight greater than or equal to 1000 g/mol.

3. Composition according to one of claims 1 and 2, characterized in that the polyamide selected from polyamide 6, polyamide 6,6, their blends and their copolymers.

4. Composition according to one of claims 1 and 2, characterized in that the polyamide is a linear polyamide.

5. Composition according to one of claims 1 and 2, characterized in that the polyamide contains a macromolecular chain a star or N-clicks the Noi form.

6. Composition according to one of claims 1 and 2, characterized in that the polyamide is a copolymer of polyamide, with a statistical tree-like structure.

7. Composition according to one of claims 1 and 2, characterized in that the polyamide is a composition comprising a linear polyamide and polyamide with a star and/or H-shaped, and/or tree structure.

8. Composition according to one of claims 1 and 2, characterized in that the polyamide is a composition comprising a hyperbranched copolymer polyamide.

9. The composition according to claim 1, characterized in that the compound a is a polyisocyanate.

10. The composition according to claim 9, characterized in that the polyisocyanate is a polyisocyanate of the formula (I)

Y-(-N=C=O)n,

where Y is a polyvalent substituted or unsubstituted aromatic, aliphatic, cycloaliphatic or heterocyclic group containing or not containing heteroatoms, and n is at least equal to 1.

11. Composition according to one of p or 10, characterized in that the polyisocyanate is a diisocyanate or triisocyanate.

12. Composition according to one of claim 9 or 10, characterized in that the polyisocyanate is isocyanurate.

13. Composition according to one of claims 1 and 2, characterized in that compound a is different from the prepolymer or polymer.

14. The composition according to claim 1, characterized in that the isocyanate GRU the dust connection And protected by a protective group.

15. The composition according to 14, characterized in that the protective group is a lactam, preferably caprolactam.

16. Composition according to one of 14 or 15, characterized in that the temperature of the removal of protection from isocyanate groups, compounds And exceeds the melting point or softening polyamide Century

17. Composition according to one of claims 1, 2, 9, 10, 14 or 15, characterized in that the compound is a dicarboxylic acid.

18. Composition according to one of claims 1, 2, 9, 10, 14 or 15, characterized in that the compound is a polyamide Century

19. Composition according to one of claims 1, 2, 9, 10, 14 or 15, characterized in that it contains a pore-forming agent.

20. Composition according to one of claims 1, 2, 9, 10, 14 or 15, characterized in that it contains the seed, and/or surfactant and/or a plasticizer.

21. Composition according to one of claims 1, 2, 9, 10, 14 or 15, characterized in that it contains reinforcing fillers such as fiberglass matting compounds such as titanium dioxide or zinc sulfide, pigments, dyes, protective additives from the action of heat or light, bioactive agents, agents, preventing pollution, antistatic agents and/or flame-retardant agents.

22. A method of obtaining a polyamide foam capable of foaming composition according to one of claims 1 to 21, comprising the following stages:

a) the composition of the heating of the Ute to the temperature at least 80°C

b) stabilize the obtained honeycomb structure.

23. The method according to item 22, wherein the temperature during stage (a) is greater than or equal to the melting point or softening of this polyamide composition.

24. The method according to one of item 22 or 23, characterized in that the temperature of stage a) is greater than or equal to the temperature of removal protection isocyanate groups of compound A.

25. The method according to one of p and 23, wherein during stage a) introducing a pore-forming agent.

26. The method according to one of p and 23, wherein during stage a) introducing a seed crystal, and/or surfactant and/or a plasticizer.

27. The method according to one of p and 23, wherein during stage a) introducing a reinforcing fillers such as glass, matting agents, pigments, dyes, substances that protect from the action of heat or light, bioactive agents, agents, preventing pollution, and/or antistatic agents.

28. The method according to one of p and 23, characterized in that stage b) carry out physical and/or chemical means.

29. Polyamide foam obtained by the method according to one of PP-28.

30. Foam according to clause 29, characterized in that it has a density less than or equal to 0.5 g/cm3preferably less than or equal to 0.3 g/cm3.



 

Same patents:

FIELD: medicine.

SUBSTANCE: invention relates medical technique and can be used while producing of artificial cardiac valves with one or more cusps from polymer composite. Producing method of artificial cardiac valves cusp consists in form manufacturing for cusp molding. Then the molding of cusp is made of the polymer composite containing 78-92 mas.% polyamid and 8-22 mas.% opaque medium, dispersed in polyamid. As preferential opaque medium barium sulphate is used. Polymer material can contain fine acetylene black in quantity of 1-2 mas.%. In one of the method realisation variants molding form is made according to molding sizes 1-5% less than necessary and cusp after the molding is placed in anticoagulating agent solution till swelling on 1-5%. Invention allows simplifying and decreasing the cost on the cusp producing method, improving hemocompatibility and construction reliability of artificial cardiac valve in more burden areas.

EFFECT: improvement of reliability of artificial cardiac valve with simplifying and cost decreasing of producing method.

8 cl, 2 ex

FIELD: chemistry; inorganic.

SUBSTANCE: invention is related to a composition for production of insulating coatings on working surfaces of parts of machines, mechanisms and process equipment, e.g., flange joints in trunk pipelines. The composition comprises the following proportion of components, % by mass: 0.1-10.0 elastic modifier, 0.1-3.0 disperse filler, 0.1-0.5 functional additive, the balance to 100 being polyamide matrix. Disperse particles of structured elastomer in the form of ground rubber of 10-100 mcm particle sizes are used as the elastic modifier. Montmorillonite, or flint, or tripoli are used as the disperse filler. Dibutyl phthalate or dioctyl phthalate are used as the functional additive. The invention makes it possible to improve adhesive, deformation and insulating properties of the coating as well as its resistance to thermal-oxidative media.

EFFECT: improvement of properties of insulating coatings.

2 tbl, 10 ex

FIELD: physics.

SUBSTANCE: invention refers to size control method for disperse particles in thermoplastic elastomer composition. Disperse particle size control method includes mixing in melt of the following: (A) halogenated isobutylene elastomer, (B) polyamide, (C) dispersion supplement, and (D) traditional additives. Resulting mixture is subjected to dynamic vulcanization thus forming dynamically vulcanized resin mix; halogenated isobutylene elastomer is dispersed in polyamide matrix at volume-averaged diameter of dispersion particles Dv from 0.01 to 2.5 μm.

EFFECT: thermoplastic elastomer composition with controllable size of disperse elastomer particles and improved durability and impermeability.

8 cl, 2 dwg, 3 tbl, 13 exrsid7429359

FIELD: technological processes.

SUBSTANCE: invention is related to composition for single-layer reservoirs such as bottles, to reservoir in the form of bottle or its pre-form, to polyester reservoirs. Composition includes the following components: polyester, partially aromatic polyamide, ionic component that improves miscibility and cobalt salt. Ionic component is copolyester that contains metal sulfonate salt. Polyester reservoir, which is manufactured out of above mentioned composition, is characterized with rate of oxygen penetrability of < 0.01 (CTD) cm3/m2 atmospheres 24 hours after 100 hours in oxygen and carbon-dioxide gas passage rate below 7 cm3/bottle/24 hours, based on 0.5 l bottle.

EFFECT: increases barrier properties of reservoir and improves its colour and transparency.

27 cl, 13 tbl, 11 ex, 2 dwg

FIELD: polymer materials.

SUBSTANCE: thermoplastic elastomer composition contains dynamically vulcanized mixture of partially vulcanized halogenated isobutylene elastomer, polyamide, and conventionally utilized additives, wherein stretching elasticity modulus at 100% elongation for elastomer distributed in polyamide is less than 0.60 MPa and wherein halogenated elastomer is, in particular, brominated or chlorinated one. Preparation of thermoplastic elastomer composition involves dynamic vulcanization of halogenated isobutylene elastomer, polyamide, and conventionally utilized additives at temperature lower than 185°C.

EFFECT: improved durability and flexibility of composition.

11 cl, 2 tbl, 2 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to thermoplastic polymer composition, to products therefrom, and to use of hyper-branched (co)polymer. Composition contains matrix M including at least one thermoplastic(co)polymer and at least one additive, namely, functionalized hyper-branched (co)polymer, which is used as modifier of rheological properties. Functionalized hyper-branched (co)polymer is selected from group consisting of polyesters, polyester-amides, and polyamides. At least 50% of end groups of hyper-branched (co)polymer are functionalized by radical R2, which represents substituted or unsubstituted silicone-type hydrocarbon radical, linear or branched alkyl, aromatic, arylalkyl, alkylaryl, or cycloaliphatic radical optionally incorporating one or several unsaturated bonds and/or one or several heteroatoms. Composition is processed into products via molding, injection casting, injection casting with blowing, extrusion, and spinning.

EFFECT: improved rheological and mechanical properties of composition.

22 cl, 3 dwg, 9 tbl, 20 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to thermoplastic polymer composition, to products therefrom, and to use of hyper-branched (co)polymer. Composition contains matrix M including at least one thermoplastic(co)polymer and at least one additive, namely, functionalized hyper-branched (co)polymer, which is used as modifier of rheological properties. Functionalized hyper-branched (co)polymer is selected from group consisting of polyesters, polyester-amides, and polyamides. At least 50% of end groups of hyper-branched (co)polymer are functionalized by radical R2, which represents substituted or unsubstituted silicone-type hydrocarbon radical, linear or branched alkyl, aromatic, arylalkyl, alkylaryl, or cycloaliphatic radical optionally incorporating one or several unsaturated bonds and/or one or several heteroatoms. Composition is processed into products via molding, injection casting, injection casting with blowing, extrusion, and spinning.

EFFECT: improved rheological and mechanical properties of composition.

22 cl, 3 dwg, 9 tbl, 20 ex

FIELD: composite materials.

SUBSTANCE: invention provides structural- and antifriction-destination six-block polyamide-based polymer material, which is, in particular, intended for manufacturing parts with low coefficient of friction and meeting requirements of shock and thermal stability. According to first embodiment, in polyamide composite material composed of six-block polyamide matrix and matrix-modifying carbon additive, said carbon additive is fullerene C60 or fullerene C70, or mixture thereof in amounts from 0.0001 to 1.5%. According to second embodiment, in polyamide composite material composed as above, said carbon additive is fullerene soot containing 3-16% fullerene C60 or fullerene C70, or mixture thereof and used in amount 0.01 to 3.0%.

EFFECT: addition of fullerene materials results increased strength and elasticity, reduced coefficient of friction with metals and wear, increased softening, melting and in-air destruction temperatures, and increased heat conductivity without deterioration in density and moisture absorption.

2 cl, 1 dwg, 2 tbl, 6 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to thermoplastic elastomer composition for manufacturing products such as films, which composition contains dynamically curable mixture of (A) halogenated isobutylene/p-methylstyrene copolymer, (B) polyamide, and (C) antioxidant having melting point above 70°C and below 200°C, granulated elastomer (A) obtained by granulation in presence of antioxidant (C) as granulator being dispersed as a domain in the continuous phase of polyamide (B) and composition containing (A) and (B) components being dynamically cured. Thus obtained film is characterized by better stretching than film made from composition containing curing agent as granulator and by excellent durability and stability at low temperature as compared to film made from talc-containing composition.

EFFECT: increased durability, heat resistance, elasticity and air impermeability.

7 cl, 3 tbl, 5 ex

FIELD: polymer materials.

SUBSTANCE: invention provides granule containing matrix of star-shaped polyamide and fibers, which granule can be obtained when performing following steps. (a) At least one matrix of star-shaped polyamide in molten state is combined with fibers selected from group consisting of continuous fibers and fibers with lengths constituting 80% granule length and preferably at least 100% granule length. Matrix of star-shaped polyamide is obtained by copolymerization of mixture of monomers containing polyfunctional compound including at least three identical reactive functional groups such as amino groups and carboxylic acid groups, in particular monomers depicted by following general formulae: X-R2-Y (IIa) and/or

(IIb), if needed, monomers of general formula Z-R2-Z (III), wherein Z represents functional group identical with reactive functional groups of polyfunctional compound; R1 and R2, the same or different, represent substituted or unsubstituted aliphatic, cycloaliphatic, or aromatic hydrocarbon radicals containing from 2 to 20 carbon atoms and optionally include heteroatoms such as nitrogen and oxygen atoms; Y represents primary amino group when X is carboxylic acid group or Y represents carboxylic acid group when X is amino group. (b) Composition obtained in step (a) is the molded into stick, which is cur into granules. Granules are used to prepare high-strength products.

EFFECT: increased strength of granules.

14 cl, 5 tbl, 10 ex

The invention relates to a new, stable to hydrolysis of aliphatic polyetherimides with high molecular weight and containing partially isocyanate end groups of the chains, which are particularly used for obtaining which add rigidity to the Shoe material

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing stable aqueous dispersions of polycarbodiimide for using as a cross-linking agent and no containing organic solvents. Method is realized by carrying out interaction of polyisocyanate in the presence of 0.5-3% of catalyst in reaction for formation of carbodiimide to form polycarbodiimide intermediate substance at 120-1800C for aliphatic polyisocyanate and at 80-1200C for aromatic polyisocyanate up to preparing 5-10% of NCO wherein polyisocyanate is represented by toluene-2,4-diisocyanate, toluene-2,6-diisocyanate or their mixture, diphenyl-4,4'-diisocyanate, 1,4-phenylenediisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate, 1,6-hexyldiisocyanate, 1,4-cyclohexyldiisocyanate, norbornyldiisocyanate or their mixture. Then method involves carrying out break and/or elongation of polycarbodiimide chain of intermediate substance by addition of equivalent compound comprising hydrophilic group and one or more amino- and/or hydroxyl functional groups during formation of polycarbodiimide intermediate substance or after formation of polycarbodiimide at temperature 70-1000C for aliphatic polycarbodiimide intermediate substance and at temperature 40-700C for aromatic polycarbodiimide intermediate substance. Then reaction in mixture is carried out up to disappearance of isocyanate functional group wherein a hydrophilic group-containing compound is represented by polyethoxymono- or diol, polyethoxy/polypropoxymono- or diol, polyethoxymono- or diamine, polyethoxy/polypropoxymono- or diamine, diol or diamine with polyalkoxy-containing by-side chain, hydroxy- or aminoalkylsulfonate, or dialkylaminoalkyl alcohol or -amine, or their mixture. Prepared compound is dispersed in water at temperature 40-1000C at pH 11-14 by addition of a base and/or buffer to water used for dispersing, and/or to prepared aqueous dispersion wherein a base is represented by alkaline metal hydroxide, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, or trialkylamine, or trialkylamine containing hydroxy-groups, and wherein buffer is represented by usually used buffer with effective pH value 11-14. Polycarbodiimide dispersions prepared by above described method are stable for at least some weeks at temperature 500C. Also, invention describes a covering mixture comprising polycarbodiimide dispersions and solidified material prepared by applying abovementioned covering mixture on substrate and evaporation of water.

EFFECT: improved preparing method of dispersions.

3 cl, 2 tbl, 15 ex

FIELD: polymer production.

SUBSTANCE: invention relates to process of producing elastomeric polyurethane material having Shore hardness up to 5 (DIN 53505), density 500 kg/m3 or higher (DIN 53420), compressive load (40%) deflection 600 kPa or less (DIN 53577), and elasticity 25% or less (ISO 8307). Process is accomplished by interaction of (i) polymethylene-polyphenylene-polyisocyanate with average isocyanate functionality 2.4 or more; (ii) polyol with average equivalent mass at least 500 and average nominal hydroxyl functionality 2-4; (iii) polyoxyalkylenemonool with nominal hydroxyl functionality 1 and average equivalent mass at least 500; and (iv) optional additives and auxiliary substances known per se in amount less than 5%. Reaction is carried out at index 90-110 and equivalent amount of polymer (iii) lies within a range of 25-80% based on accessible NCO equivalents. Elastomeric polyurethane material accordingly obtained is a soft gel-like material showing some degree of tackiness. Advantageously, this material is obtained using as little additives and auxiliary substances as possible, which results in reduced content of washed out products and residual reactive group in elastomeric polyurethane material. The latter can be employed in vehicle interior objects such as elbow-rests and instrumentation panels, in bicycle sittings, and in mouse tappets.

EFFECT: improved consumer's quality of elastomers.

1 tbl, 12 ex

FIELD: composite materials.

SUBSTANCE: in particular, invention relates to employment of polyisocyanates compositions as binders for composites containing lignocellulose fibers such as oriented wood chipboard.

EFFECT: improved performance characteristics regarding detachment of product as compared to conventional polyisocyanates employed for binding lignocellulose material.

11 cl, 7 tbl, 8 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to polyurethane-polyol compositions comprising product of reaction of a polyol and Herbert alcohol, the two containing In average 12 carbon atoms. Preferred polyols are α,β-diols and α,β-diols. Polyurethane-polyol compositions exhibit very low viscosity and are particularly suitable in coating compositions with very low content of volatile organics. Hardened coating obtained from claimed compositions ensure high resistance to cracking and can be applied on various substrates such as metal, plastic, wood, glass, ceramics.

EFFECT: increased strength of coatings on a variety of substrates.

5 cl, 3 tbl

FIELD: polymers, covering compositions.

SUBSTANCE: invention relates to photoactivating aqueous-base covering composition. The proposed composition comprises the following components: a)(meth)acryloyl-functional polyurethane dispersion wherein this (meth)acryloyl-functional polyurethane comprises from 5 to 18 weight % of alkylene-oxide groups and (meth)acryloyl functionality represents a value in the range from 2 to 40, and b) UV-initiating agent. The presence of reactive diluting agent in the covering composition is preferable. (Meth)acryloyl-functional polyurethane can be prepared by carrying out the following interactions: a) at least one organic polyisocyanate; b) optionally, at least one organic compound comprising at least two isocyanate-reactive groups and having an average molecular mass in the range from 400 to 6000 Da; c) at least one isocyanate-reactive and/or isocyanate-functional compound comprising non-ionogenic dispersing groups; d) at least one isocyanate-reactive (meth)acryloyl-functional compound; e) optionally, at least one chain elongating agent comprising active hydrogen, and f) optionally, at least one compound comprising active hydrogen and ionic groups. Aqueous-base covering composition is useful especially for applying as a clear cover. Covers based on the proposed composition show resistance to water, solvents and scratches and flexibility and high adhesion also.

EFFECT: improved and valuable properties of composition.

15 cl, 12 tbl, 17 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to ionomer thermoplastic polyurethane, method for preparation thereof, use of indicated ionomer thermoplastic polyurethane to prepare aqueous dispersions thereof, as well as to a method for preparing aqueous dispersions of ionomer thermoplastic polyurethanes. Ionomer thermoplastic polyurethane is prepared via continuous reaction of (i) 4-50% if diisocyanate; (ii) 35-95% of bifunctional polyatomic alcohol selected from group comprising (a) polycaprolactone with mean molecular mass between 500 and 15000 and general formula I: (I), (b) polyesterdiol with mean molecular mass between 500 and 15000 and general formula II: (II), (c) polyesterdiol selected from polypropylene glycol, polytetramethylene glycol, and polyethylene glycol, (d) polycarbonatediol with mean molecular mass between 500 and 15000 and general formula III: (III), and (e) copolymers obtained from two bifunctional polyatomic alcohol from groups (a), (b), (c), or (d); (iii) 0.2-16% of chain-elongation glycol of general formula IV: (IV); and (iv) 0.2-3% of chain-elongation anionic-type ionomer glycol of general formula V: (V).

EFFECT: enabled preparation of ionomer polyurethane suitable for being stored in solid form for subsequent preparation of aqueous dispersions of thermoplastic polyurethanes appropriate as industrial adhesives and coating materials for flexible and rigid substrates.

34 cl, 2 tbl, 10 ex

The invention relates to rigid polyurethane foams and methods for their preparation using a mixture of polyols

FIELD: polymer materials.

SUBSTANCE: invention relates to ionomer thermoplastic polyurethane, method for preparation thereof, use of indicated ionomer thermoplastic polyurethane to prepare aqueous dispersions thereof, as well as to a method for preparing aqueous dispersions of ionomer thermoplastic polyurethanes. Ionomer thermoplastic polyurethane is prepared via continuous reaction of (i) 4-50% if diisocyanate; (ii) 35-95% of bifunctional polyatomic alcohol selected from group comprising (a) polycaprolactone with mean molecular mass between 500 and 15000 and general formula I: (I), (b) polyesterdiol with mean molecular mass between 500 and 15000 and general formula II: (II), (c) polyesterdiol selected from polypropylene glycol, polytetramethylene glycol, and polyethylene glycol, (d) polycarbonatediol with mean molecular mass between 500 and 15000 and general formula III: (III), and (e) copolymers obtained from two bifunctional polyatomic alcohol from groups (a), (b), (c), or (d); (iii) 0.2-16% of chain-elongation glycol of general formula IV: (IV); and (iv) 0.2-3% of chain-elongation anionic-type ionomer glycol of general formula V: (V).

EFFECT: enabled preparation of ionomer polyurethane suitable for being stored in solid form for subsequent preparation of aqueous dispersions of thermoplastic polyurethanes appropriate as industrial adhesives and coating materials for flexible and rigid substrates.

34 cl, 2 tbl, 10 ex

FIELD: polymers, covering compositions.

SUBSTANCE: invention relates to photoactivating aqueous-base covering composition. The proposed composition comprises the following components: a)(meth)acryloyl-functional polyurethane dispersion wherein this (meth)acryloyl-functional polyurethane comprises from 5 to 18 weight % of alkylene-oxide groups and (meth)acryloyl functionality represents a value in the range from 2 to 40, and b) UV-initiating agent. The presence of reactive diluting agent in the covering composition is preferable. (Meth)acryloyl-functional polyurethane can be prepared by carrying out the following interactions: a) at least one organic polyisocyanate; b) optionally, at least one organic compound comprising at least two isocyanate-reactive groups and having an average molecular mass in the range from 400 to 6000 Da; c) at least one isocyanate-reactive and/or isocyanate-functional compound comprising non-ionogenic dispersing groups; d) at least one isocyanate-reactive (meth)acryloyl-functional compound; e) optionally, at least one chain elongating agent comprising active hydrogen, and f) optionally, at least one compound comprising active hydrogen and ionic groups. Aqueous-base covering composition is useful especially for applying as a clear cover. Covers based on the proposed composition show resistance to water, solvents and scratches and flexibility and high adhesion also.

EFFECT: improved and valuable properties of composition.

15 cl, 12 tbl, 17 ex

FIELD: polymer materials.

SUBSTANCE: invention relates to polyurethane-polyol compositions comprising product of reaction of a polyol and Herbert alcohol, the two containing In average 12 carbon atoms. Preferred polyols are α,β-diols and α,β-diols. Polyurethane-polyol compositions exhibit very low viscosity and are particularly suitable in coating compositions with very low content of volatile organics. Hardened coating obtained from claimed compositions ensure high resistance to cracking and can be applied on various substrates such as metal, plastic, wood, glass, ceramics.

EFFECT: increased strength of coatings on a variety of substrates.

5 cl, 3 tbl

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