Method for preparing polyamide

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing polyamide that can be used as a structural material. Polyamide is prepared by co-polymerization reaction of ε-caprolactam and 1,6-hexamethylenediisocyanate taken among the group of di-isocyanates or urethane prepolymer SKU-PFL-100 in the mass ratio = (95-90):(5-10) in the presence of catalyst and activating agent. As a catalyst method involves using ε-caprolactam Na-salts and 2,4-toluylenedi-isocyanate as an activating agent. The process is carried out at temperature (180 ± 5)°C up to depletion of lactam cycles followed by heating the reaction mass for 2 h. Invention provides preparing polyamides with enhanced values of destroying stress (breaking point) and to expand assortment of methods providing preparing polyamides with different physical-mechanical properties.

EFFECT: improved preparing method.

2 tbl, 10 ex

 

The invention relates to a method for producing polyamide, which can be used as a structural material.

A known method of producing polyamide by polymerization of the monomer ε-caprolactam in the presence of Na-salt ε-caprolactam and activator of 2,4-toluylene diisocyanate by heating, the process is conducted in solution or in the melt at 160-220°C for 1-1 .5 hours, see Peak IS, Azeri S.A. Technology of plastics. M: "High school", 1975, s-291.

The disadvantage is that the polyamides obtained by a known method, have a high melting temperature, which increases their processing.

The closest in technical essence is a method of producing polyamide by copolymerization ε-caprolactam and selected from the group of the diisocyanate 1,6-hexamethylenediisocyanate, or urethane prepolymer SKU-PFL-100, or 4,4'-diphenylmethanediisocyanate in the presence of a catalyst Na-salt ε-caprolactam and activator of 2,4-toluylene diisocyanate at a mass ratio of ε-caprolactam and diisocyanate (95-70):(5-30), respectively, at a temperature (180±5)°With the process leading to the exhaustion of the lactam cycles, see patent RU No. 2218360, IPC 7 C 08 G 69/18, 2003.

The disadvantage is that the polyamides obtained by a known method, have little value destructive voltage.

Ass is whose inventions is expanding Arsenal of ways, allowing to obtain polyamides having different mechanical properties, including those with elevated values destructive voltage.

The technical problem is solved by a method of producing polyamide by copolymerization ε-caprolactam and selected from the group of the diisocyanate 1,6-hexamethylenediisocyanate or urethane prepolymer SKU-PFL-100 when the mass ratio (95-90):(5-10), respectively, in the presence of a catalyst Na-salt ε-caprolactam and activator of 2,4-toluylene diisocyanate at a temperature (180±5)°while lactam cycles, in which, after exhaustion of the lactam cycles are heating the reaction mixture for 2 hours.

Technical solution allows you to expand the Arsenal of ways to obtain polyamides having different mechanical properties, including high value destructive voltages up to 131%.

Substances used in the method is:

ε-caprolactam, GOST 7850-86;

Na-salt ε-caprolactam. The product of the interaction with Na ε-caprolactam in a molar ratio of 0.25:1), respectively; 2,4-toluylenediisocyanate, THE 113-38-95-90;

4,4'-diphenylmethanediisocyanate, THE 113-38-176-90;

1,6-hexamethylenediisocyanate, THE 113-03-332-79;

the urethane prepolymer of the SSI-PFL-100, TU 38-103-137-78.

The invention is illustrated by the following specific examples is carried out:

Example 1.

Into a container equipped with a reflux condenser and a stirrer, a load of 95 g (95 wt.%) ε-caprolactam and 1 g (1 wt.% of the total load) catalyst Na-salt ε-caprolactam, is melted at a temperature of 80-90°With the current of inert gas (argon), then added with stirring 5 g (5 wt.%) 1,6-hexamethylenediisocyanate and activator - 2,4-diisocyanate in a quantity of 1 g (1 wt.% of the total load). The temperature was raised to (180±5)°and the process is conducted at a specified temperature until exhaustion lactam cycles. Then conduct the heating of the reaction mass within 2 hours.

Example 2.

Into a container equipped with a reflux condenser and a stirrer, was loaded to 90 g (90 wt.%) ε-caprolactam and 1 g (1 wt.% of the total load) catalyst Na-salt ε-caprolactam, is melted at a temperature of 80-90°With the current of inert gas (argon), then added with stirring 10 g (10 wt.%) 1,6-hexamethylenediisocyanate and activator - 2,4-diisocyanate in a quantity of 1 g (1 wt.% of the total load). The temperature was raised to (180±5)°and the process is conducted at a specified temperature until exhaustion lactam cycles. Then conduct the heating of the reaction mass within 2 hours.

Example 3.

Into a container equipped with a reflux condenser and a stirrer, a load of 95 g (95 wt.%) ε-caprolactam and 1 g (1 wt.% of the total for the power) catalyst Na-salt ε -caprolactam, is melted at a temperature of 80-90°With the current of inert gas (argon), then added with stirring 5 g (5 wt.%) the urethane prepolymer of the SSI-PFL-100 and activator - 2,4-diisocyanate in a quantity of 1 g (1 wt.% of the total load). The temperature was raised to (180±5)°and the process is conducted at a specified temperature until exhaustion lactam cycles. Then conduct the heating of the reaction mass within 2 hours.

Example 4.

Into a container equipped with a reflux condenser and a stirrer, was loaded to 90 g (90 wt.%) ε-caprolactam and 1 g (1 wt.% of the total load) catalyst Na-salt ε-caprolactam, is melted at a temperature of 80-90°With the current of inert gas (argon), then added with stirring 10 g (10 wt.%) the urethane prepolymer of the SSI-PFL-100 and activator - 2,4-diisocyanate in a quantity of 1 g (1 wt.% of the total load). The temperature was raised to (180±5)°and the process is conducted at a specified temperature until exhaustion lactam cycles. Then conduct the heating of the reaction mass within 2 hours.

The ratio of components in the examples of specific performance and physical-mechanical parameters are shown in table 1, table 2 shows data on the prototype.

Table 1.
Claimed is the object
# exampleThe mass ratio of ε-CL:diisocyanateTtimes., °σρ, MPaε, %
195:518055,7305
290:1016566,7310
395:520243,3324
490:1020348,0354

Table 2.
Prototype
# exampleThe mass ratio of ε-CL:diisocyanateTtimes.,°σρ, MPaε, %
195:518050,7305
290:1016546,7310
395:521240,198.3
490:1020639,8165
595:518528,0238
690:1048 21,0243

Note:

1 and 2 examples as diisocyanate take 1,6-hexamethylenediisocyanate;

3 and 4 examples as diisocyanate take the urethane prepolymer - SKU-PFL-100;

5 and 6 examples as diisocyanate take 4,4'-diphenylmethanediisocyanate.

The softening temperature (Ttime.) of the obtained copolymer is determined by using thermomechanical analysis.

Physico-mechanical tests: ultimate tensile stress (σρ, MPa) and elongation (ε, %) performed according to GOST 11262-80.

As can be seen from the examples of embodiment, the inventive method allows to obtain copolymers with a high value destructive voltage (43,3-66,7 MPa) compared to the prototype (21,0-50,7 MPa), without increasing the softening temperature that does not increase the cost of their processing.

Thus, the claimed object expands the Arsenal of ways to get polyamides with higher breaking strain.

A method of producing polyamide by copolymerization ε-caprolactam and selected from the group of the diisocyanate 1,6-hexamethylenediisocyanate or urethane prepolymer SKU-PFL-100 when the mass ratio (95-90):(5-10), respectively, in the presence of a catalyst Na-salt ε-caprolactam and activator - 2,4-toluylenediisocyanate is at a temperature (180± 5)°while lactam cycles, characterized in that after the exhaustion of the lactam cycles are heating the reaction mixture for 2 hours



 

Same patents:

FIELD: organic chemistry, structural materials.

SUBSTANCE: claimed polyamide is obtained by copolymerization of ε-caprolactam and 2,4-toluylenediisocyanate in mass ratio of (95-95):(3-5) in presence of ε-caprolactam sodium salt at 180±5)°C up to exhausting of lactam cycles. Then reaction mass is heated for 2 h.

EFFECT: polyamides with increased elongation and failure stress; as well as with various physical and mechanical properties.

2 tbl, 8 ex

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FIELD: organic chemistry, structural materials.

SUBSTANCE: claimed polyamide is obtained by copolymerization of ε-caprolactam and 2,4-toluylenediisocyanate in mass ratio of (95-95):(3-5) in presence of ε-caprolactam sodium salt at 180±5)°C up to exhausting of lactam cycles. Then reaction mass is heated for 2 h.

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2 tbl, 8 ex

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FIELD: organic chemistry, structural materials.

SUBSTANCE: claimed polyamide is obtained by copolymerization of ε-caprolactam and 2,4-toluylenediisocyanate in mass ratio of (95-95):(3-5) in presence of ε-caprolactam sodium salt at 180±5)°C up to exhausting of lactam cycles. Then reaction mass is heated for 2 h.

EFFECT: polyamides with increased elongation and failure stress; as well as with various physical and mechanical properties.

2 tbl, 8 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing polyamide that can be used as a structural material. Polyamide is prepared by co-polymerization reaction of ε-caprolactam and 1,6-hexamethylenediisocyanate taken among the group of di-isocyanates or urethane prepolymer SKU-PFL-100 in the mass ratio = (95-90):(5-10) in the presence of catalyst and activating agent. As a catalyst method involves using ε-caprolactam Na-salts and 2,4-toluylenedi-isocyanate as an activating agent. The process is carried out at temperature (180 ± 5)°C up to depletion of lactam cycles followed by heating the reaction mass for 2 h. Invention provides preparing polyamides with enhanced values of destroying stress (breaking point) and to expand assortment of methods providing preparing polyamides with different physical-mechanical properties.

EFFECT: improved preparing method.

2 tbl, 10 ex

FIELD: organic chemistry, polymers, chemical technology.

SUBSTANCE: invention relates to a method for preparing polyamide that can be used as a structural material. Polyamide is prepared by co-polymerization reaction of ε-caprolactam and 1,6-hexamethylene diisocyanate in the mass ratio = (95-90):(5-10) in the presence of catalyst and an activating agent. As catalyst method involves using ε-caprolactam Li-salt and 2,4-toluylene diisocyanate as an activating agent. The process is carried out at temperature (180 ± 5)°C up to depletion of lactam cycles followed by heating the reaction mass for 2 h. Invention provides preparing polyamides with enhanced values of destroying stress (breaking point) and provides expanding assortment of methods providing preparing polyamides with different physical-mechanical properties also.

EFFECT: improved preparing method.

2 tbl, 4 ex

FIELD: production of high-viscosity or high-stability poly-condensate of polyamide on base of polyamide-6 or demonomerized polyamide-6.

SUBSTANCE: proposed method consists in delivery of poly-condensate melt to upper end of reaction stage followed by distribution by means of distributing units with surface increasing members. Waste reagents are removed from reaction stage above poly-condensate melt level by means of inert gas or vacuum. Time of keeping the product in settler is so selected that poly-condensate in chemical balance is formed at lower end of reaction stage; part of this poly-condensate is returned to distributing members at upper end of reaction stage. Remaining part of poly-condensate melt is removed from reaction stage for further use in accordance with selected flow rate. Device proposed for realization of this method includes reactor (1) where surface increasing members (3) are arranged; distributor (2) for feeding the poly-condensate melt is located above members (3). Reactor (1) has at least one gas outlet (4) on its upper end; level gauge (5) is mounted in settler. Two proportioners (P2 and P3) mounted on lower end of reactor (1) are connected in series and one end of return main (6) located between these proportioners is connected with inlet main (7) before distributor (2); end of distributor (2) is connected with other end of return main (6).

EFFECT: increased viscosity of poly-condensate.

8 cl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing nylon microspheres and nylon microspheres produced using said method. Described is a method of producing nylon microspheres, involving steps (1), (2) and (3) or steps (1'), (2) and (3), where at step (1) a radically polymerisable monomer is dispersed in a molten lactam monomer and a free-radical polymerisation initiator is added for radical polymerisation of the radically polymerisable monomer to obtain a mixture of a free-radical polymer and a lactam monomer; or at step (1') a mixture of a free-radical polymer and a molten lactam monomer is obtained; and at step (2) an initiator and an activator used for anionic polymerisation with opening of the lactam monomer ring are added to the mixture obtained at step (1), from which the remaining radically polymerisable monomer and water are removed or to the mixture obtained at step (1') for anionic polymerisation with opening of the lactam ring to obtain a polymer alloy of free-radical polymer/polyamide; and at step (3) the free-radical polymer in the molten polymer obtained at step (2) is removed through dissolution to obtain nylon microspheres. The invention also describes nylon microspheres obtained using said method, in which the weight-average molecular weight of nylon is in the range of 1.2×105-6.3×104, and the particle size of the nylon microspheres is in the range of 1.4-318 mcm.

EFFECT: obtaining nylon microspheres with a regular spherical shape and possibility of controlling the particle size and molecular weight of the nylon microspheres.

10 cl, 16 ex, 1 dwg

FIELD: technological processes.

SUBSTANCE: invention relates to versions of composition for producing molded polyamides, to cured lactam melt, to injection polyamide and method for production thereof, as well as to use of one or more composition components. Composition for molded polyamides producing contains following components: a) hardened lactam melt, including from 0.1 to 5 wt% of, at least one polymer carbodiimide and/or at least one uretdione as activator, and b) hardened lactam melt, including from 0.2 to 5 wt% of catalyst such as magnesium lactam-halide, alkali metal aluminodilactam, alkali and/or alkali-earth metal lactam, and/or component c) hardened lactam melt, including simultaneously from 0.2 to 5 wt% of said catalyst and from 0.1 to 5 wt% of said activator. Hardened lactam melt is obtained by mixing melt consisting of caprolactam and 0.1–5 wt% of said activator, with melt consisting of caprolactam and 0.2–5 wt% of said catalyst at temperature from 70 to 120 °C during period of time from 1 to 60 seconds. One or more said composition components are used for production of cast polyamides. Method of cast polyamides producing involves, that performing polymerization of one or several hardened lactams in injection mold at temperature from 100 to 160 °C.

EFFECT: invention allows to increase compositions storage life and produce polyamide with homogeneous structure.

14 cl, 2 tbl, 14 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a composition for use as an activator of anionic polymerisation of lactam, a preparation method thereof, a method of producing polyamide, a moulded product and an article comprising same. Composition contains at least one aliphatic isocyanate compound, containing at least two isocyanate groups in amount of 20 to 80 wt% and at least one lactone containing 4-7 carbon atoms. Method for preparing composition involves mixing said components. Method of producing polyamide by anionic polymerisation of lactam involves a step of adding said composition to lactam.

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13 cl, 2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: method for producing a moulded polyamide consists in that, at least, one lactam melt with an anionic polymerization catalyst and optionally a tertiary amine co-activator and/or dibutyltin dilaurate is mixed with, at least, one lactam melt with a biuret polymerization activator or uretdione, and, if necessary, the aforementioned co-activator. The polymerization is then carried out in a mould at a temperature of, at least, 80°C to 130°C, preferably of 110°C to 130°C. Herewith the co-activator must be contained in, at least, one of the lactam melts. If necessary, a lactam melt with a co-activator can be introduced before polymerization. The moulded polyamide is used to make rollers, preferably for passenger elevators, and preforms, preferably containers, gears, tubes, rods and plates for engineering and the automotive industry.

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7 cl, 1 tbl, 1 ex

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