High-viscosity nylon composition

Abstract

The invention discloses a high-viscosity nylon composition. The high-viscosity nylon composition comprises at least one polyamide; the polyamide is a polyfunctional compound comprising at least three acid or amine functional groups capable of forming an amide bond with functional groups of a dicarboxylic acid monomer and a diamine monomer by polymerizing the dicarboxylic acid monomer and the diamine monomer, and optionally polymerizing a bifunctional and / or monofunctional compound comprising an acid or amine functional group capable of forming an amide functional group with the functional groups of the dicarboxylic acid monomer and the diamine monomer. The present invention has developed polyamides modified with polyfunctional and optionally bifunctional and / or monofunctional compounds, the modified polyamides having high viscosity and excellent mechanical properties, while avoiding gelation using conventional polymerization processes.

Description

Technical Field

[0001] The invention belongs to the technical field of nylon materials, and in particular relates to a high-viscosity nylon composition. Background Art

[0002] Polyamide is a synthetic polymer widely used in the manufacture of a variety of shaped articles, including molded parts and injection molded parts. For example, in the automotive industry, the polymer is melted into a fluid and then processed by injection molding or blow molding to form automotive interior parts. The viscosity of the polymer after melting will affect the deformation of the decorative parts after molding. Low viscosity will result in strong shaping after blow molding, but the material is prone to slight deformation during cooling, affecting the quality of the decorative parts. In order to improve the production quality of automotive decorative parts, a high-viscosity nylon composition is provided. Summary of the invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a high-viscosity nylon composition, which solves the problem in the prior art that nylon materials are prone to micro-deformation during the blow molding process due to low viscosity.

[0004] In order to solve the above technical problems, the present invention discloses a high-viscosity nylon composition, comprising: at least one polyamide; the polyamide is prepared by polymerizing dicarboxylic acid monomers and diamine monomers, polymerizing a multifunctional compound containing at least 3 acid or amine functional groups that can form amide bonds with the functional groups of the dicarboxylic acid monomers and the diamine monomers, and optionally polymerizing a bifunctional and / or monofunctional compound containing an acid or amine functional group that can form an amide functional group with the functional groups of the dicarboxylic acid monomers and the diamine monomers.

[0005] Furthermore, the composition has an AA-type dicarboxylic acid monomer (a) and a BB-type diamine monomer.

[0006] Furthermore, the above composition comprises a multifunctional compound (b) having at least 3 functional groups A or B.

[0007] Further, the functional groups A and B are functional groups that can react together to form an amide bond.

[0008] Furthermore, the above-mentioned multifunctional compound (b) is an aliphatic, alicyclic and / or aromatic hydrocarbon compound containing 1 to 100 carbon atoms and possibly containing one or more heteroatoms.

[0009] Furthermore, the above-mentioned multifunctional compound (b) is selected from nitrilotrialkylamine; dialkylenetriamine; bis-hexamethylenetriamine; trialkylenetetramine and tetraalkylenepentylamine, 4-aminomethyl-1,8-octanediamine, melamine and polyalkyleneamine.

[0010] Furthermore, the VN of the polyamide is 160 ml / g to 300 ml / g.

[0011] Furthermore, the dicarboxylic acid monomer is adipic acid, terephthalic acid, isophthalic acid, pimelic acid, suberic acid, sebacic acid or dodecanedioic acid.

[0012] Furthermore, the diamine monomers are hexamethylenediamine, butanediamine, meta-xylylenediamine, isophoronediamine, 3,3',5-trimethyl-1,6-hexamethylenediamine and methyl-1,5-pentanediamine.

[0013] Compared with the prior art, the present application can obtain the following technical effects: The present invention develops polyamides modified with multifunctional and optionally difunctional and / or monofunctional compounds, the modified polyamides having high viscosity and excellent mechanical properties while avoiding gelation using conventional polymerization methods.

[0014] Of course, any product implementing this application does not necessarily need to achieve all of the technical effects described above at the same time. DETAILED DESCRIPTION

[0015] The following will explain the implementation methods of the present application in detail with reference to examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0016] The polyamide is obtained by polymerizing dicarboxylic acid monomers and diamine monomers, by polymerizing a polyfunctional compound comprising at least 3 acid or amine functional groups capable of forming amide bonds with the functional groups of the dicarboxylic acid monomers and diamine monomers, and optionally by polymerizing a difunctional and / or monofunctional compound comprising acid or amine functional groups capable of forming amide functional groups with the functional groups of the dicarboxylic acid monomers and diamine monomers. The polymerization process is conventional and corresponds to the process usually used for polymerizing polyamides based on diacid and diamine monomers, for example for polyamide PA-6,6.

[0017] The composition has a dicarboxylic acid monomer (a) of the AA type and a diamine monomer of the BB type, and contains a multifunctional compound (b) having at least 3 functional groups A or B, wherein the functional groups A and B are functional groups capable of reacting together to form an amide bond, and the multifunctional compound (b) is an aliphatic, alicyclic and / or aromatic hydrocarbon compound containing 1 to 100 carbon atoms and possibly containing one or more heteroatoms.

[0018] Functional groups A and B are functional groups that can react together to form an amide bond. Functional group A can be a carboxylic acid functional group or a salt thereof, or a precursor functional group of functional group A that can generate functional group A in the polymerization medium. Mention may be made especially of nitrile, primary amide, anhydride and ester functional groups. Functional group B can be a primary amine functional group or a salt thereof, or a precursor functional group of functional group B that can generate functional group B in the polymerization medium. Mention may be made especially of isocyanate and carbamate functional groups.

[0019] The polyfunctional compound (b) is selected from the group consisting of nitrilotrialkylamines; dialkylenetriamines; bis-hexamethylenetriamine; trialkylenetetramines and tetraalkylenepentylamines, 4-aminomethyl-1,8-octanediamine, melamine and polyalkyleneamines.

[0020] The monomers may be optionally mixed in the form of salts of dicarboxylic acid monomers and diamine monomers. It is particularly preferred in the present invention to use the constituent monomers of polyamide PA-6,6, which are adipic acid and hexamethylenediamine or their salts, such as hexamethylenediammonium adipic acid, also known as nylon salt or N salt. The modified polyamide of the present invention may include one or more dicarboxylic acids and one or more diamines of various types. The multifunctional compound (b) of the present invention includes at least 3 acid or amine functional groups. Advantageously, this compound has 3 acid or amine functional groups. This compound preferably has 3 amine functional groups. This multifunctional compound is generally an aliphatic, alicyclic and / or aromatic hydrocarbon compound containing 1 to 100 carbon atoms and may contain one or more heteroatoms. The heteroatoms may be O, S, N or P.

[0021] The dicarboxylic acid monomer is adipic acid, terephthalic acid, isophthalic acid, pimelic acid, suberic acid, sebacic acid or dodecanedioic acid.

[0022] The diamine monomers are hexamethylenediamine, butanediamine, meta-xylylenediamine, isophoronediamine, 3,3',5-trimethyl-1,6-hexamethylenediamine and methyl-1,5-pentanediamine.

[0023] The polymerization process of the present invention is carried out according to standard operating conditions for polymerizing dicarboxylic acids and diamines. Such a polymerization process may simply comprise: (1) heating a mixture of monomers and a polyfunctional compound under stirring and pressure.

[0024] (2) The mixture is maintained at pressure and temperature for a given time, water vapor is removed using a suitable device, then the pressure is reduced and maintained at a temperature above the melting point of the mixture, especially under the autogenous pressure of water vapor, under nitrogen or under vacuum, for a given time, thereby allowing the polymerization to continue by removing the water formed. It is entirely possible to carry out the polymerization until the thermodynamic equilibrium of the polyamide is obtained. It is preferred to add the polyfunctional and optionally monofunctional compounds at the beginning of the polymerization. In this case, the polymerization of the mixture of dicarboxylic acid monomers and diamine monomers and the polymerization of the polyfunctional and monofunctional compounds are carried out. It is entirely possible to add common additives, such as catalysts, especially phosphorus-containing catalysts, defoamers and light or heat stabilizers, at the beginning, during or at the end of the polymerization.

[0025] (3) At the end of the polymerization, the polymer may be advantageously cooled with water, extruded, and then pulverized to produce granules.

[0026] Example: Preparation of polymers, carried out in a heated autoclave including a stirring device and a device for discharging volatile by-products. 27 kg of N salts (equimolar amounts of adipic acid and hexamethylenediamine), optionally a variable amount of hexamethylenetriamine (BHT), optionally 45 g of isophoronediamine (IPD) (0.13 mol %) and 100 g of a defoamer are added and mixed with 13 kg of soft water, and the entire mixture is then introduced into an autoclave at a temperature of 200° C. The stirred mixture is given a temperature of 275° C. and a pressure of 13 bar. Next, the pressure and temperature are kept constant for 1 hour. During this step, water is evaporated. Then, the pressure is gradually reduced to 1 bar absolute and 275° C. within 1h30min. Finally, a fission stage is carried out for 1h at a pressure of 0.75 bar absolute. The molten polymer is then extruded into rods, then rapidly cooled with water and cut into pellets. The polymers are given in detail in Table 1

[0027] (1) According to standard ISO 307, the viscosity value is expressed in ml / g and is measured using a 0.5% polymer solution dissolved in 90% formic acid.

[0028] (2) (*) Increased polymerization cycles to achieve high viscosity (longer polymerization cycles or polymerization cycles under vacuum / large amounts of catalyst).

[0029] (3) Catalyst: Type 1: NaH2PO2.H2O / Type 2: H3PO4

[0092] -GTA, GTC and ΔGT are expressed as meq / kg.

[0030] It is observed that it is not possible to achieve high viscosities in solution or in the melt without adding catalysts and / or without higher polymerization cycles (C1). Indeed, for the equilibrium polymer in a normal polymerization cycle (C3), where the best viscosity increase should be observed, a viscosity of only 164 ml / g is obtained. It is also observed that it is even more difficult to obtain high viscosities at GT differences of about 40-50 meq / kg (C2). On the contrary, it is entirely possible to obtain polyamides with the desired characteristics using standard polymerization cycles by using the multifunctional compounds of the invention.

[0031] The present invention develops polyamides modified with multifunctional and optionally difunctional and / or monofunctional compounds, the modified polyamides having high viscosity and excellent mechanical properties while avoiding gelation using conventional polymerization methods.

[0032] The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A high-viscosity nylon composition comprising: at least one polyamide; Characterized in that the polyamide is prepared by polymerizing dicarboxylic acid monomers and diamine monomers, polymerizing a multifunctional compound containing at least 3 acid or amine functional groups that can form amide bonds with the functional groups of the dicarboxylic acid monomers and the diamine monomers, and optionally polymerizing a difunctional and / or monofunctional compound containing an acid or amine functional group that can form an amide functional group with the functional groups of the dicarboxylic acid monomers and the diamine monomers.

2. The high-viscosity nylon composition according to claim 1, characterized in that The composition has a dicarboxylic acid monomer (a) of AA type and a diamine monomer of BB type.

3. The high-viscosity nylon composition according to claim 1, characterized in that The composition comprises a multifunctional compound (b) having at least 3 functional groups A or B.

4. The high-viscosity nylon composition according to claim 3, characterized in that The functional groups A and B are functional groups that can react together to form an amide bond.

5. The high-viscosity nylon composition according to claim 3, characterized in that: The polyfunctional compound (b) is an aliphatic, alicyclic and / or aromatic hydrocarbon compound containing 1 to 100 carbon atoms and possibly containing one or more heteroatoms.

6. The high-viscosity nylon composition according to claim 3, characterized in that: The multifunctional compound (b) is selected from the group consisting of nitrilotrialkylamines; dialkylenetriamines; bis-hexamethylenetriamine; trialkylenetetramines and tetraalkylenepentylamines, 4-aminomethyl-1,8-octanediamine, melamine and polyalkyleneamines.

7. The high-viscosity nylon composition according to claim 1, characterized in that The VN of the polyamide is 160 ml / g to 300 ml / g.

8. The high-viscosity nylon composition according to claim 1, characterized in that The dicarboxylic acid monomer is adipic acid, terephthalic acid, isophthalic acid, pimelic acid, suberic acid, sebacic acid or dodecanedioic acid.

9. The high-viscosity nylon composition according to claim 1, characterized in that The diamine monomers are hexamethylenediamine, butanediamine, meta-xylylenediamine, isophoronediamine, 3,3',5-trimethyl-1,6-hexamethylenediamine and methyl-1,5-pentanediamine.

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