JPH0125491B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyamide elastomer having a basic skeleton of segmented polyether ester amide. Like polyether ester and polyether amide, polyether ester amide is known as a thermoplastic elastomer with excellent impact resistance and rubber elasticity (U.S. Pat. Nos. 4,207,410 and 4,230,838), but it is not actually on the market. The only polyamide elastomer whose main component is polydodecanamide/poly(tetramethylene oxide) glycol. This polymer has physical properties and moldability comparable to polyester elastomers, and has the advantage of being able to create more flexible copolymer compositions, but has the disadvantages of insufficient high-temperature properties, oil resistance, and chemical resistance. be. In particular, the elastic modulus and strength drop significantly in the high temperature range of 100°C or higher, and the reality is that it is virtually unusable at temperatures of 120°C or higher. It is also known that when polycaproamide (nylon 6) is used in the hard segment, a polyether ester amide with a relatively high melting point can be obtained, but this polymer has a high nylon 6 component and is excellent in the hard polymer region. Although it exhibits high temperature characteristics,
A flexible polymer region containing a large amount of poly(alkylene oxide) glycol component causes a rapid drop in melting point, making it impossible to design a polymer that has both flexibility and high-temperature properties. This copolymer system is also difficult to manufacture industrially, as lactam is distilled off from the system during polycondensation. Furthermore, when polyhexamethylene adipamide (nylon 66) is used for the hard segment, it has extremely low affinity with polyether components such as poly(tetramethylene oxide) glycol, and it is used over almost the entire copolymer composition range. As a result, a coarse phase-separated system is formed, making it impossible to produce a thermoplastic elastomer exhibiting excellent rubber properties. In view of the shortcomings of conventional polyamide elastomers, the present inventors have developed a polyamide elastomer that maintains its flexibility, impact resistance, and excellent moldability at low temperatures, and has excellent mechanical strength and rubber even in the high temperature range of 100°C or higher. The present invention has been arrived at through extensive research aimed at producing a thermoplastic elastomer exhibiting these properties. That is, the present invention provides (a) hexamethylene diammonium sebacate or hexamethylene diammonium dodecanoate, (b) poly(alkylene oxide) having a carbon number/oxygen number ratio of 2.3 or more and a number average molecular weight of 300 to 3000. ) glycol and (c) dicarboxylic acid having 4 to 20 carbon atoms in substantially equimolar amount to the above poly(alkylene oxide) glycol (a)/[(b)+(c)]=50-10/50-90 (weight%)
150 to 280℃.
After heating and stirring to homogenize, place under high vacuum.
The present invention provides a method for producing a polyamide elastomer having a melting point of 160°C or higher, which is characterized by carrying out melt polymerization at 220 to 300°C. The polyamide hard segment of polyether ester amide constituting the basic skeleton of the polyamide elastomer obtained in the present invention is polyhexamethylene sebaamide (nylon 610) or It is a polyamide unit whose main component is polyhexamethylene dodecane amide (nylon 612), but small amounts of copolymerized components include heptamethylene diamine, octamethylene diamine, decamethylene diamine, undecamethylene diamine, and bis(p-aminocyclohexyl). Diamines such as methane and xylylene diamine, adipic acid, azelaic acid, isophthalic acid, terephthalic acid, and cyclohexane-1,4-
Dicarboxylic acid units such as dicarboxylic acid may be included. As the polyether component constituting the polyether ester soft segment of the polyether ester amide of the present invention, poly(alkylene oxide) glycol having a carbon/carbon number ratio of 2.3 or more and a number average molecular weight of 300 to 3000 is used. carbon/
Poly(alkylene oxide) with an oxygen number ratio of 2.3 or more
Glycols include poly(1,2- and 1,
Examples include 3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, poly(hexamethylene oxide) glycol, block or random copolymers of ethylene oxide and propylene oxide, block or random copolymers of ethylene oxide and tetrahydrofuran, etc. In particular, poly(tetramethylene oxide) glycol is preferably used because of the excellent physical properties of polyether ester amide, such as heat resistance, water resistance, mechanical strength, and elastic recovery. The number average molecular weight of poly(alkylene oxide) glycol is
It can be used in the range of 300 to 3000, but a molecular weight range that does not cause coarse phase separation during polymerization and has excellent high-temperature to low-temperature properties and mechanical properties is selected, and this optimum molecular weight range depends on the type of poly(alkylene oxide) glycol. It's different. For example, poly(propylene oxide) glycol preferably has a molecular weight of 300 to 2,000, particularly preferably 600 to 1,200, and poly(tetramethylene oxide) glycol preferably has a molecular weight of 500 to 2,500, particularly preferably 500 to 1,500. The dicarboxylic acid having 4 to 20 carbon atoms, which is another component constituting the ether ester soft segment unit of the polyether ester amide of the present invention, is the same as the dicarboxylic acid used for the polyamide hard segment component, that is, sebacic acid. Although it is preferable to use dodecanedioic acid, they do not necessarily have to match, and aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6 -Dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-
Aromatic dicarboxylic acids such as 4,4'-dicarboxylic acid, diphenoxyethane dicarboxylic acid, sodium 5-sulfoisophthalate, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, dicyclohexyl-4,4' - Alicyclic dicarboxylic acids such as dicarboxylic acids may be mentioned. Among these, terephthalic acid is particularly preferred, as it gives good results in terms of polymerization reactivity, color tone, and polymer physical properties (particularly mechanical strength at high temperatures). The use of dicarboxylic acids other than terephthalic acid, sebacic acid, and dodecanedioic acid may impair high-temperature properties, so their use is limited depending on the copolymer composition and purpose of use. That is, the most preferred copolymer composition in the present invention is nylon 6.10 or nylon 6.12, especially nylon 6.12, as a hard segment, poly(tetramethylene oxide) glycol with a number average molecular weight of 500 to 2500, and sebacic acid ( A polyether ester amide block copolymer containing as a soft segment a polyether ester of dodecanedioic acid (when the hard segment is nylon 6/10), dodecanedioic acid (when the hard segment is nylon 6/12), or terephthalic acid, especially terephthalic acid. It is a combination. The present invention is a method for producing a copolyether ester amide comprising these polyamide hard segments and polyether ester soft segments, and the copolymerization ratio of polyamide units and polyether ester units is (10-50)/(90-50) ( weight ratio)
It is preferable that the copolymerization is carried out so that the following physical properties are obtained. Especially the polyether ester soft segment is 55

[Table] It is preferable that the copolymer is copolymerized in the range of ~80% by weight, and this copolymer is not only flexible and has excellent rubber elasticity at room temperature, but also has excellent properties as an elastomer in a wide temperature range from low to high temperatures. Demonstrates physical properties and formability. If the polyether ester component exceeds 90%, the length of the amide hard segment of the resulting polyether ester amide becomes too short, resulting in a polymer with poor physical properties, which is not preferred. Among the polymer physical property items mentioned above, the most important item that defines the high-temperature properties, which is the main objective of the present invention, is the melting point, and the crystallinity, crystal morphology,
It depends on the perfection of the crystal, but generally 160
The polymer should be designed to exhibit a melting point above 180°C, preferably above 180°C. As for the polymerization method of polyetheresteramide having such a structure, it is possible to synthesize a polyetheresteramide that meets the purpose of the present invention by the following method. (a) hexamethylene diammonium sebacate (nylon 610 salt) or hexamethylene diammonium dodecanoate (nylon 612 salt);
(b) poly(alkylene oxide) glycol and
(c) Poly(alkylene oxide) glycol and dicarboxylic acid in substantially equimolar amounts are subjected to a reaction system at the above-mentioned copolymerization ratio, and heated at 150 to 280°C.
After heating and stirring to homogenize, heat under high vacuum to 220~
Melt polymerize at 300℃. As the starting material, poly(alkylene oxide) glycol may be liquid, but generally it is solid, so it is homogenized by heating and stirring at 150 to 280°C, preferably 180 to 260°C, for about 10 to 60 minutes under normal pressure. It can be made into a liquid mixture. Here, the state of "homogeneous" does not necessarily mean that the materials are mixed on a molecular order, but rather refers to a state where no layer separation or the like has occurred as a whole, even if the material is cloudy in appearance. The reaction system is then brought into a vacuum system and preferably heated to about 20 to 90 °C.
The polymerization conditions are high vacuum 220-300℃ for 1 minute. High vacuum means a range of about 15 mmHg or less, preferably 5 mmHg or less, more preferably 1 mmHg or less, which is equivalent to the degree of vacuum used in ordinary melt polymerization of polyester. By this method, the block polyether ester amide of the present invention can be industrially advantageously synthesized as a colorless, highly polymerized polymer; however, it is necessary to bring the amide-forming unit into the reaction system without first converting it into a salt form. You can also do it. In this case, it is necessary to control the reaction conditions of the dissolution homogenization process so that the amine is not distilled out of the system. Alternatively, a method may be used in which the amide-forming unit component and the dicarboxylic acid component are brought into the form of a dicarboxylic acid-terminated polyamide prepolymer and then reacted with poly(alkylene oxide) glycol. The dicarboxylic acid component and the dicarboxylic acid component constituting the polyether ester unit need to be the same or terephthalic acid. Otherwise, the polyamide hard segments would be randomly copolymerized, making it impossible to produce a flexible elastomer with excellent high-temperature properties, which is the object of the present invention. In the polymerization reaction of the polyether ester amide of the present invention, a titanium catalyst such as a tetraalkyl titanate such as tetrabutyl titanate, a titanium metal salt of oxalate such as potassium titanium oxalate, a titanium catalyst such as dibutyltin oxide, dibutyltin laurate, monobutyltin oxide, etc. Preferably used are tin-based catalysts, zirconium tetraalkoxide-based catalysts such as zirconium tetrabutoxide and zirconium isopropoxide, hafnium tetraalkoxide-based catalysts such as hafnium tetraethoxide, and lead-based catalysts such as lead acetate. These compounds act as polymerization catalysts to promote the reaction, and are advantageous in easily producing the colorless, highly polymerized polymer of the present invention, which has excellent physical properties. Further, polyfunctional compounds such as trimesic acid, glycerin, and pentaerythritol can be included as long as they do not cause gelation. The degree of polymerization of the polyether ester amide of the present invention varies depending on the use, purpose, and molding method, but the relative solution viscosity (ηr) measured at 0.5% concentration in orthochlorophenol at 25°C is 1.5 or more, especially It should preferably be 1.7 or higher. The polyether ester amide block copolymer of the present invention can contain heat-resistant and light-resistant stabilizers such as antioxidants, thermal decomposition inhibitors, and ultraviolet absorbers during polymerization or after polymerization and before molding. Examples of heat-resistant stabilizers include 4,4'-bis(2,6
-ditert-butylphenol), 1,3,5-trimethyl-2,4,6-tris(3,5-ditert-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3(3,5- di-tert-butyl-
4-Hydroxyphenyl)propionate]methane, N,N'-hexamethylene-bis(3,5-
Various hindered phenols such as di-tert-butyl-4-hydroxyhydrocinnamic acid amide), N,
Aromatic amines such as N'-bis(β-naphthyl)-p-phenylenediamine and 4,4'-bis(4-α,α-dimethylbenzyl)-diphenylamine, dilaurylthiodipropionate, etc. Examples include sulfur compounds, phosphorus compounds, alkaline earth metal oxides, nickel salts of Schiff's bases, cuprous iodide and/or potassium iodide. In addition, as light stabilizers, substituted benzophenones, benzotriazoles, bis-(2,2,
6,6-tetramethyl-4-piperidine) sebacate and 4-benzoyloxy-2,2,6,6-
Mention may be made of piperidine compounds such as tetramethylpepyridine. The polyether ester amide block copolymer of the present invention also contains hydrolysis resistance improvers, coloring agents (pigments, dyes), antistatic agents, conductive agents, flame retardants, reinforcing materials, fillers, lubricants, nucleating agents, release agents, etc. A molding agent, plasticizer, adhesion aid, adhesive, etc. can be optionally contained. As described above, since the polyamide elastomer of the present invention has a specific copolymer composition, it exhibits excellent oil and chemical resistance, as well as excellent rubber elasticity and mechanical strength in a wide temperature range from low to high temperatures. The present invention will be explained below with reference to Examples. In the examples, parts mean parts by weight unless otherwise specified. Example 1 33.5 parts of hexamethylenediamine-dodecanedioic acid salt (nylon 612 salt) prepared from hexamethylenediamine and dodecanedioic acid, number average molecular weight 650
poly(tetramethylene oxide) glycol
53.9 parts of dodecanedioic acid and 19.1 parts of N,N'-hexamethylene-bis(3,5-di-t-butyl-4
- Hydroxyhydrocinnamic acid amide) (antioxidant; trade name "Irganox" 1098) 0.20 part and tetrabutyl titanate catalyst 0.05 part into a reaction vessel equipped with a helical ribbon stirring blade,
After heating and stirring for 1 hour at 230°C under a _N2 stream to obtain a homogeneous solution,
The polymerization conditions were brought to 270℃ and below 0.5mmHg.
When the polymerization reaction was carried out under these conditions for 4 hours and 10 minutes, a viscous, colorless and transparent molten polymer was obtained. When this polymer was discharged as a strand into water, a flexible, non-tacky strand was obtained. The obtained polyether ester amide () had a relative viscosity (ηr) of 1.82 measured in orthochlorophenol at 25°C at a concentration of 0.5%, and a crystal melting point (Tm) determined by DSC.
The temperature was 193℃. Note that in the following examples and comparative examples, ηr and Tm are also determined by this method. The mechanical properties measured from the press-formed product are shown in Table 1, and it is flexible and has rubber elasticity.
It showed excellent mechanical strength even at high temperatures. Comparative Example 1 38.2 parts of aminododecanoic acid, 50.1 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 650
Polyether ester amide (') was prepared under the same polymerization conditions as in Example 1 using 17.7 parts of dodecanedioic acid and 17.7 parts of dodecanedioic acid as starting materials. This polyether ester amide had a ηr of 1.80 and a Tm of 139°C.
As shown in Table 1, the mechanical properties were as good as those of Example 1 from low temperatures to room temperature, but the elastic modulus and strength decreased significantly at high temperatures, and at 120°C, it was almost fluid. Comparative Example 2 34.8 parts of hexamethylenediamine-adipate (nylon 66 salt), 59.9 parts of poly(tetramethylene oxide) glycol having a number average molecular weight of 650, and 13.5 parts of adipic acid were polymerized in the same manner as in Example 1. Coarse phase separation occurred and the polymer turned brown and cloudy. In addition, the degree of polymerization is low, and the elastic recovery rate is low.
Only a polymer with low strength could be obtained.

[Table] Example 2-4 Nylon 6/12 salt, poly(tetramethylene oxide) glycol (PTMG) with a number average molecular weight of 650
-650) and terephthalic acid as starting materials under the same polymerization conditions as in Example 1 to prepare three types of polyether ester amides (), (), and (). The physical properties of these polymers are shown in Table 2.

【table】

[Table] Example 5 27.9 parts of nylon 6/12 salt, 66.4 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 1000
Polyether ester amide () was polymerized under the same conditions as in Example 1, except that 11.1 parts of terephthalic acid and 11.1 parts of terephthalic acid were used. The degree of polymerization was increased to a predetermined torque in a polymerization time of 3:55 minutes, and a pale white translucent polymer was obtained. The hard/soft ratio of this polymer is 25/
75, and the physical property values were as follows. ηr 1.90 Tm (℃) 198 Mechanical properties 23℃ Shore D hardness 30 Tensile modulus (Kg/cm ² )350 Breaking strength (〃 )320 Elongation at break (%) 1050 Elastic recovery rate (%) 88 80℃ Tensile elasticity Modulus (Kg/cm ² )280 Breaking strength (〃 )170 Breaking elongation (%)950 120℃ Tensile modulus (Kg/cm ² )110 Breaking strength (〃 )120 Breaking elongation (%)950 Comparative example 3 Example 5 When the polymer was polymerized so that the hard/soft ratio was 60/40, the polymer became milky white and coarse phase separation was formed. The polymer discharged from the polymerization vessel showed a large balancing effect and could not be taken off as a strand. Comparative Example 4 Synthesis of polyether ester amide with the same hard/soft ratio as in Example 5 using 27.9 parts of nylon 612 salt, 71.1 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 3500, and 4.7 parts of dodecanedioic acid as starting materials. However, the polymer exhibited a pearly, milky white color and coarse phase separation was formed. Although it was difficult to take this polymer into strands, it was made into pellets, and its physical properties were measured as a pressed sheet. At 23℃, the breaking strength was 130 kg/cm ^{2 and the breaking elongation was 130 kg/cm 2} .
340%, but showed almost no strength at 80°C. Example 6 27.9 parts of nylon 612 salt and 11.1 parts of terephthalic acid were placed in a polymerization container and heated at 230°C to 250°C under a _N2 stream.
Heat and stir for an hour, and add the number average molecular weight to the reaction mixture.
66.4 parts of poly(tetramethylene oxide) glycol 100 and 0.05 parts of tetrabutyl titanate and 0.20 parts of "Irganox" 1098 were added;
Thereafter, the polymerization conditions were brought to the same conditions as in Example 1, and the predetermined torque was reached after 5 hours and 30 minutes. The physical properties of this polymer are shown in Table 3. Comparative Example 5 In Example 6, 27.9 parts of nylon 612 salt, 9.9 parts of adipic acid, and 67.6 parts of poly(tetramethylene oxide) having a number average molecular weight of 1000 were used as starting materials. Even after 8 hours of polymerization, the predetermined torque was not reached and the color of the polymer was brownish, so it was taken out and subjected to evaluation. As shown in Table 3, this polymer has a low melting point and poor high temperature properties.

【table】

[Table] Example 7 Polyether ester was produced under the same polymerization conditions as in Example 1, except that 28.2 parts of nylon 610 salt, 62.5 parts of poly(tetramethylene oxide) glycol with a number average molecular weight of 650, and 16.0 parts of terephthalic acid were used as starting materials. The amide was polymerized. The physical properties of the obtained polymer were as follows. ηr 1.86 Tm (℃) 208 Mechanical properties 23℃ Shore D hardness 34 Tensile modulus (Kg/cm ² ) 380 Breaking strength (〃 ) 240 Elongation at break (%) 700 Elastic recovery rate (%) 76 80℃ Tensile elasticity Modulus (Kg/cm ² ) 280 Strength at break ( 〃 ) 130 Elongation at break (%) 850 120℃ Tensile modulus (Kg/cm ² ) 120 Strength at break ( 〃 ) 75 Elongation at break (%) 550

Claims (1)

[Scope of Claims] 1 (a) hexamethylene diammonium sebacate or hexamethylene diammonium dodecanoate, (b) poly( (a)/[(b)+(c)]=50-10/50 ~90 (wt%)
150 to 280℃.
After heating and stirring to homogenize, place under high vacuum.
A method for producing a polyamide elastomer having a melting point of 160°C or higher, which comprises performing melt polymerization at 220 to 300°C.