JPH0126367B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a hydrophilic polyamide elastomer. Polyether ester amide, in which a polyamide segment and a polyether ester segment are bonded together, is known as a hydrophilic polyamide (Japanese Patent Application Laid-Open No. 159586/1986). This polyether ester amide uses poly(alkylene oxide) glycol in the polyether ester segment, so it is a polymer that exhibits considerable flexibility and also has some degree of hydrophilicity, but it is used in fields that require even more hydrophilicity. When applied to , the hydrophilic ability is insufficient, and the mechanical strength, especially the breaking strength, is insufficient. Therefore, the present inventors have developed a method that has at least the same flexibility as known polyetheresteramides,
Moreover, as a result of extensive research into a method for producing a hydrophilic polyamide elastomer with further improved hydrophilicity and mechanical strength, the present invention has been arrived at. That is, the present invention provides (A) aliphatic ω-amino acids and/or ω-lactams having 5, 10, or 11 methylene groups [amino acid compounds
(a)], an aliphatic diamine having 2, 4 or 6 methylene groups, and an aliphatic dicarboxylic acid having 0, 2 or 4 methylene groups, and the total number of methylene groups of the aliphatic diamine component and the aliphatic dicarboxylic acid component is 2. , 4, 6, or 8 (B) A polyamide starting material (B) consisting of a combination of two types of nylon salts (B) A polyether ester consisting of a polyethylene glycol having a number average molecular weight of 350 to 4000 and a dicarboxylic acid having 4 to 20 carbon atoms Both starting materials are fed to a polycondensation reaction system to copolymerize 60 to 5% by weight of polyamide units and polyether ester units.
In the method for obtaining a polyether ester amide consisting of 40 to 95% by weight,
The present invention provides a method for producing a hydrophilic polyamide elastomer, characterized in that a polyamide starting material and a polyether ester starting material are supplied to the reaction system so that the value of . x=a ₁・b+a ₂・c/b+2c In the above formula, a ₁ : Number of methylene groups in the amino acid compound (a) a ₂ : Total number of methylene groups in the nylon salt (b) b : Amino acid compound (based on the polyamide starting material) (a) Mol% c: Same as above, nylon salt (b) mole% The method for producing the hydrophilic polyamide elastomer according to the present invention will be specifically described below. First, prepare the starting materials. The polyamide starting material has methylene groups of 5, 10 or
consisting of 11 aliphatic ω-amino acids and/or ω-lactams [amino acid compound (a)], an aliphatic diamine having 2, 4 or 6 methylene groups, and an aliphatic dicarboxylic acid having 0, 2 or 4 methylene groups, It consists of two types of combinations of nylon salts (b) in which the total number of methylene groups in the aliphatic diamine component and the aliphatic dicarboxylic acid component is 2, 4, 6, or 8. As described above, it is necessary to use two types of polyamide-forming components in combination in order to produce a polyamide elastomer in which the crystallinity of the polyamide units is disturbed and the hydrophilicity is further improved. Examples of the amino acid compound (a) include ω-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, caprolactam, and laurolactam, among which ω-aminocaproic acid is preferred. Examples of nylon salt (b) include nylon 2.2
Salt, nylon 2/4 salt, nylon 2/6 salt, nylon 4/2 salt, nylon 4/4 salt, nylon 4/4 salt
Among them, nylon 2.6 salt and nylon 4.6 salt are preferred. The polyether ester starting material consists of polyethylene glycol having a number average molecular weight of 350 to 4000, preferably 350 to 3000, and a dicarboxylic acid having 4 to 20 carbon atoms. Examples of dicarboxylic acids include aromatic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, and diphenoxyethanedicarboxylic acid. group dicarboxylic acids,
1,4-cyclohexanedicarboxylic acid, 1,2-
Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and dicyclohexyl-4,4'-dicarboxylic acid, and aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid (decanedicarboxylic acid). can be mentioned. Especially adipic acid, suberic acid,
Sebacic acid, terephthalic acid, isophthalic acid, 1,
4-cyclohexanedicarboxylic acid, dodecanedioic acid, and the like are preferably used in terms of polymerizability, color tone, and physical properties of the polymer. Once the starting materials are prepared, they are subjected to a polymerization reaction, and in order to obtain a polyamide elastomer with specific properties, copolymerized polyamide units and polyether ester units are respectively added to the final polyether ester amide. 60-5% by weight, preferably 50-10% by weight, and 40-95% by weight,
The proportion is preferably 50 to 90% by weight. A further feature of the present invention is that polyamide starting materials and polyether ester starting materials are supplied to the reaction system so that the value of x expressed by the following formula is 2.9 to 4.9. x=a ₁・b+a ₂・c/b+2c In the above formula, a ₁ : Number of methylene groups in the amino acid compound (a) a ₂ : Total number of methylene groups in the nylon salt (b) b : Amino acid compound (based on the polyamide starting material) mol% of a) c: mol% of nylon salt (b) as above The value of x in the above formula corresponds to the average number of methylene groups per amide group in the copolyamide unit. That is, it is the number of methylene groups in the polyamide block (a ₁ ·b + a ₂ ·c) divided by the number of amide groups in the polyamide block (b + 2c). A high concentration of amide groups increases hydrophilicity and also increases the cohesive force of the amide block, so the smaller the value of x, the better the properties such as hydrophilicity, mechanical strength, elastomer properties, and thermal properties, but the polymerization temperature Taking into account the constraints and polymerization reactivity, it is necessary that the value is 2.9 or more. Also, as the value of x increases, the above properties, especially hydrophilicity, become insufficient, so 4.9
It is necessary that the following is true. In addition, when supplying the starting material to the polymerization reaction system, if a part of the starting material is dissipated during the polymerization reaction process, an excess amount may be supplied to the polymerization reaction system in consideration of the amount of the dissipation. In the method for producing a hydrophilic polyamide elastomer of the present invention, the method for polymerizing polyetheresteramide is not particularly limited, and any known method can be used. For example, an amino acid compound (a), a nylon salt (b), and a dicarboxylic acid (c) are reacted in approximately equimolar ratios to create a polyamide prepolymer with carboxylic acid groups at both ends, and this is combined with poly(alkylene oxide) glycol ( d) A method of reacting under high vacuum,
Alternatively, the compounds (a), (b), (c), and (d) above are charged into a reaction tank and reacted under pressure at high temperature in the presence or absence of water to form a carboxylic acid-terminated polyamide prepolymer. A method is known in which the polymer is produced and then the polymerization is proceeded under normal pressure or reduced pressure. There is also a method in which the compounds (a), (b), (c), and (d) above are simultaneously charged into a reaction tank, melted and mixed, and then polymerized all at once under a high vacuum. It is preferable that there is less. A specific example of this method is shown below. The polymerization reaction proceeds through two operations.
One is a homogenization operation in which the starting materials are fed into a heatable container and heated and stirred to form a transparent homogeneous reaction mixture, and the other is a homogenization operation in which the reaction mixture obtained by the homogenization operation is heated under high vacuum. This is a polymerization operation in which the mixture is heated and stirred at the bottom. In the homogenization operation, the starting materials are homogeneously mixed and at the same time some reaction occurs. Homogenization at 150-260℃, preferably 180-250℃
The polymerization is carried out under an inert gas atmosphere under normal pressure for about 20 to 80 minutes, and the polymerization is carried out in the presence of a polymerization catalyst by heating at 220 to 290°C, preferably 240 to 285°C, under high vacuum for 2 to 7 hours. Stirring is continued until a predetermined degree of polymerization is reached. Here, high vacuum refers to a reduced pressure state of about 15 mmHg or less, preferably 5 mmHg or less, more preferably 1 mmHg or less. Polymerization catalysts include titanium-based catalysts, tin-based catalysts,
Zirconium-based catalysts, hafnium-based catalysts, lead-based catalysts, etc. are used. Furthermore, 4,4'-bis(2,6-di-tert-butylphenol) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert) are preferably used as heat stabilizers in the polymerization system. tert-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3
Various hinderers such as (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, N,N'-hexamethylene-bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamic acid amide) Dophenols or aromatic amines such as N,N'-bis(β-naphthyl)-p-phenylenediamine or 4,4'-bis(4-α,α-dimethylbenzyl)diphenylamine are added. Further, as a viscosity increasing agent, a multifunctional compound such as trimesic acid, glycerin, pentaerythritol, etc. may be added to the polymerization reaction system within a range in which the polyether ester amide does not gel. By the above method, a polyetheresteramide in which 60 to 5% by weight of copolyamide units and 40 to 95% by weight of polyetherester units are bonded can be obtained. This copolymer is obtained from a specific starting material, a specific amount of polyamide units and polyether ester units are copolymerized, and the polyamide unit is a copolyamide with one amide group. Since the raw materials are supplied so that the average value of the number of methylene groups per polymer is a specific value, this polymer has the following characteristics. (1) Extremely hydrophilic, with low water solubility or water absorption
Shows 200% water absorption. (2) As shown below, it is extremely flexible (low tensile modulus), has high strength, and has rubber-like elasticity (elastic recovery rate,
High rebound modulus). Breaking strength > 75Kg/cm ² Elongation at break > 200% Tensile modulus 10-1000Kg/cm ² Elastic recovery rate (after 50% elongation) > 50% Impact resilience > 40% (3) High transparency. (4) A product with a high degree of polymerization can be obtained by the method described above. The polyether ester amide of the present invention can be molded by any conventional molding method for thermoplastic plastics or rubber, such as injection molding, extrusion molding, compression molding, blow molding, calendering, or coating. It can be made into a body. Examples of molded products include photosensitive resin substrates, moisture-absorbing fibers, antistatic fibers, hygroscopic foams, conductive composites, separation membranes, medical tubes, disposable products, and the like. The present invention will be explained below with reference to Examples. In the examples, unless otherwise specified, parts mean parts by weight. Example 1, Comparative Example 1 11.6 parts of ε-aminocaproic acid, 11.8 parts of nylon 4/6 salt prepared in advance from tetramethylene diamine and adipic acid, 67.6 parts of polyethylene glycol having a number average molecular weight of 600, and 16.45 parts of adipic acid were mixed into "Irganox". 1098 (antioxidant) and 0.05 part of tetrabutyl titanate catalyst into a reaction vessel equipped with a helical ribbon stirring blade. Here, the value of x is 4.5. As a result of preliminary experiments,
32 mol% of the charged ε-aminocaproic acid
Since it is known that ε-aminocaproic acid is converted to caprolactam and distilled out of the system during the polymerization reaction, 5.5 parts of ε-aminocaproic acid was further added to the reaction vessel. The solution was then purged with N ₂ and heated and stirred at 240° C. for 40 minutes to obtain a clear homogeneous solution, which was then brought to polymerization conditions of 260° C. and 0.5 mmHg or less according to a temperature increase and pressure reduction program. When the polymerization reaction was carried out under these conditions for 4 hours and 30 minutes, a viscous, colorless and transparent molten polymer was obtained.
The polymer was discharged onto a cooling belt and pelletized. In this polyether ester amide (), the polyether ester unit accounts for 80% by weight of the total copolymer, but the type of polyamide starting material and the value of x were made to be the same as those of the polyether ester amide (). Four types of polyether ester amides () to () containing 30 to 97% by weight of polyether ester units were similarly polymerized. Polymerization reactivity of these polymers, relative viscosity (ηr) measured in orthochlorophenol at 25°C at 0.5% concentration,
Table 1 shows the results of measuring water absorption to water solubility and mechanical properties using a sheet of mm thickness. Note that () remained liquid and could not be formed into a sheet. In addition, the shore hardness and rebound modulus are values measured by stacking four sheets.

【table】

[Table] Example 2, Comparative Example 2 Seven types of polyether ester amides () to (XII) were polymerized in the same manner as in Example 1 using raw materials as shown in Table 2. Since ε-aminocaproic acid was used in both cases, the amount that would be distilled out as caprolactam, which was confirmed in preliminary experiments, was added in excess. Polyether ester amide () ~
(XI) is homogeneous and transparent during melt polymerization, and although there is a slight difference in polymerization time, the torque is 5.0Kg・cm in all cases.
It was a polymer whose ηr was between 1.70 and 1.80. However, with polyether ester amide (XII), no torque was produced even after 10 hours of continuous melt polymerization), and a practical degree of polymerization could not be achieved. The physical properties of these polymers were measured in the same manner as in Example 1. The results are also shown in Table 2. The water absorption rate of polyetheresteramide (XI) was low.

[Table] () to () are Example 2, (XI), (XII)
is Comparative Example 2. Example 3, Comparative Example 3 Six types of polyether ester amides () to () were polymerized in the same manner as in Example 1 using raw materials as shown in Table 3. During melt polymerization, polyether ester amide () to ()
All are homogeneous and transparent, and although there are slight differences in polymerization time, all have a torque of 5.0Kg・cm, and ηr is 1.60.
The above polymer was used. However, polyether ester amide () underwent emulsion phase separation, and even after 10 hours of continuous melt polymerization, no torque was produced and a high degree of polymerization could not be achieved. The physical properties of these polymers were measured in the same manner as in Example 1. The results are also shown in Table 3. Polyether ester amide () had low water absorption and poor rubber elasticity. ()～
() is Example 3, and () and () are Comparative Example 3.

【table】

Claims (1)

[Scope of Claims] 1 (A) Aliphatic ω- having 5, 10 or 11 methylene groups
It consists of an amino acid and/or an omega-lactam [amino acid compound (a)], an aliphatic diamine having 2, 4 or 6 methylene groups, and an aliphatic dicarboxylic acid having 0, 2 or 4 methylene groups; 2 of nylon salt (b) whose total number of methylene groups in group dicarboxylic acid components is 2, 4, 6 or 8;
Polyamide starting material (B) consisting of a combination of species; polyether ester starting material consisting of polyethylene glycol having a number average molecular weight of 350 to 4000 and dicarboxylic acid having 4 to 20 carbon atoms; both are supplied to a polycondensation reaction system for copolymerization. 60-5% by weight of polyamide units and polyetherester units
In the method for obtaining a polyether ester amide consisting of 40 to 95% by weight,
A method for producing a hydrophilic polyamide elastomer, characterized in that a polyamide starting material and a polyether ester starting material are supplied to the reaction system so that the value of x = a ₁ · b + a ₂ · c / b + 2 c In the above formula, a ₁ : number of methylene groups in the amino acid compound (a) a ₂ : total number of methylene groups in the nylon salt (b) b: mol% of the amino acid compound (i) based on the polyamide starting material c: nylon salt as above (b) Mol%