JPS6328446B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyamide, in which a polycarboxylic acid and a diisocyanate are reacted in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate. It is already known that polyamides can be produced from polyhydric carboxylic acids and diisocyanates.
A polyamide is obtained by reacting for 20 hours. However, the molecular weight of the products obtained by this method is low, and their main uses are varnishes, paints, adhesives, etc., and they can be processed into forms such as fibers, various molded products, and films, and exhibit sufficient physical properties. It has been difficult to produce high molecular weight polymers with a viscosity of about 1.0 or more. Furthermore, for isocyanate reactions, tertiary amines such as triethylamine and triethylenediamine, which have catalytic properties, lithium linoleate,
Salts such as sodium oleate, sodium methoxide, and cobalt naphthenate have little effect on the reaction for producing polyamide from diisocyanate and polyhydric carboxylic acid, and it has been difficult to produce high molecular weight polyamide. The inventors of the present invention have conducted intensive studies on a method for obtaining a high molecular weight polyamide by reacting this diisocyanate with a polyhydric carboxylic acid, and as a result, they have discovered an epoch-making method and have arrived at the present invention. That is, the method of the present invention comprises at least one dicarboxylic acid represented by the general formula (), a tricarboxylic acid represented by the general formula (), or a tetracarboxylic acid represented by the general formula (); In the production of a polyamide having at least one repeating unit substantially represented by general formula (), general formula (), or general formula () from at least one diisocyanate, general formula () and/or general formula () This is a method for producing polyamide, characterized in that the reaction is carried out in the coexistence of an alkali metal salt of carbonic acid or an alkali metal hydrogen carbonate compound represented by: Here, each of the general formulas () to () means the following structures, and R ¹ to R ⁴ and M
have the following meanings: R ¹ (COOH) ₂ () R ² (COOH) ₃ () R ³ (COOH) ₄ () R ⁴ (NCO) ₂ () [−CO−R ¹ −CONH−R ⁴ −NH]− () [ −CO−R ² (COOH)−CONH−R ⁴ −NH〕− () [−CO−R ³ (COOH) ₂ −CONH−R ⁴ −NH]−
() M ₂ CO ₃ () MHCO ₃ () R ¹ : A divalent group containing at least two carbon atoms, or a group that does not substantially react with both a carboxyl group and an isocyanate group. or a group in which an atom is substituted, in the above formula:
The two carboxyl groups bonded to R ¹ are bonded to two different carbon atoms contained in R ¹ . R ² : A divalent group containing at least 3 carbon atoms, or a group in which these groups are further substituted with a group or atom that does not substantially react with both a carboxyl group and an isocyanate group, and the above-mentioned During the ceremony
The three carboxyl groups bonded to R ² are each bonded to three different carbon atoms contained in R ² . R ³ : A tetravalent group containing at least 4 carbon atoms, or a group in which such a group is further substituted with a group or atom that does not substantially react with both a carboxyl group and an isocyanate group, and the above-mentioned During the ceremony
The four carboxyl groups bonded to R ³ are each bonded to four different carbon atoms contained in R ³ . R ⁴ : A divalent group containing at least two carbon atoms, or a group in which these groups are further substituted with a group or atom that does not substantially react with both carboxyl groups and isocyanate groups, and the above-mentioned During the ceremony
The two isocyanate groups bonded to R ⁴ are each bonded to two different carbon atoms contained in R ⁴ . M: Alkali metal belonging to Group A of the periodic table. When a polyhydric carboxylic acid and a diisocyanate are reacted in a substantially anhydrous organic polar solvent in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate by the method of the present invention, when the alkali metal salt is not present, The reaction rate is significantly increased and the degree of polymerization is improved compared to the conventional method, and a linear polymer with almost no network structure (gel formation) can be produced very easily. In addition, the method of the present invention produces polyamide by a polycondensation reaction that releases carbon dioxide gas, which has extremely low reactivity, and produces less by-products from the polymerization reaction than in conventional polycondensation reactions by dehydrochlorination or dehydration. Not only is there no deterioration of the polymer, but also the catalyst used is a very common alkali metal salt of carbonic acid, which is easy to obtain and handle, so it has great economic and industrial benefits. Typical polyhydric carboxylic acids represented by the above general formulas (), (), () include, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,
Terephthalic acid, isophthalic acid, hexahydroterephthalic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenyl sulfone-4,4'-dicarboxylic acid, biphenyl-4,4'-dicarboxylic acid, thiophene-2,5 -dicarboxylic acid, pyridine-2,
Butane-1 as (), 2,4-tricarboxylic acid, pentane-1,2,5-tricarboxylic acid, cyclohexane-1,2,3-tricarboxylic acid, cyclopentadienyl-3,4,4'-tricarboxylic acid, cyclopentadienyl-1 , 2,4-tricarboxylic acid, benzene-1,2,4-tricarboxylic acid, benzene-1,2,3-tricarboxylic acid, naphthalene-1,2,4-tricarboxylic acid, naphthalene-
1,2,5-tricarboxylic acid, naphthalene-2,
3,5-tricarboxylic acid, naphthalene-2,3,
6-tricarboxylic acid, 3,4,4'-biphenyltricarboxylic acid, 2,3,2'-biphenyltricarboxylic acid, 3,4,3'-diphenylsulfonetricarboxylic acid, 3,4,4'-diphenyltricarboxylic acid enyl ether tricarboxylic acid, 3,4,4'-benzophenone tricarboxylic acid, 3,3',4-benzophenone tricarboxylic acid, perylene-3,4,9-tricarboxylic acid, 2-(3,4-dicarboxylic acid) carboxyphenyl)-2-
(3-carboxyphenyl)propane, 2-(2,
3-dicarboxyphenyl)-2-(3-carboxyphenyl)propane, 1-(2,3-dicarboxyphenyl)-1-(3-carboxyphenyl)
Ethane, 1-(3,4-dicarboxyphenyl)-
1-(4-carboxyphenyl)ethane, (2,3
-dicarboxyphenyl)-(2-carboxyphenyl)methane, 2-(3,4-dicarboxyphenyl)-5-(3-carboxyphenyl)-1,3,
4-oxadiazole, 2,3,5-pyrazinetricarboxylic acid, () as butane-1,2,3,
4-tetracarboxylic acid, pentane-1,2,4,
5-tetracarboxylic acid, cyclobutane-1,2,
3,4-tetracarboxylic acid, cyclopentane-
1,2,3,4-tetracarboxylic acid, cyclohexane-1,2,3,4-tetracarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, naphthalene-1,4,5,8- Tetracarboxylic acid, naphthalene-2,3,6,7-tetracarboxylic acid,
Naphthalene-1,2,4,5-tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,5,6-biphenyltetracarboxylic acid, 2,2',3 , 3'-biphenyltetracarboxylic acid, 2,2',6,6'-biphenyltetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 2,2',3, 3'-Benzophenonetetracarboxylic acid, 2,3,3',4'-benzophenonetetracarboxylic acid, 3,3',4,4'-diphenylethertetracarboxylic acid, 3,3',4 , 4'-diphenylsulfone tetracarboxylic acid, perylene-
3,4,9,10-tetracarboxylic acid, phenanthrene-1,8,9,10-tetracarboxylic acid, anthracene-2,3,6,7-tetracarboxylic acid,
p-benzoquinone-2,3,5,6-tetracarboxylic acid, azobenzene-3,3',4,4'-tetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)propane, 2 ,2-bis(2,3-
dicarboxyphenyl)propane, 1,1-bis(2,3-dicarboxyphenyl)ethane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)methane, 2,
2-bis(3,4-dicarboxyphenyl)hexafluoropropane, thiophene-2,3,4,
5-tetracarboxylic acid, furan-2,3,4,5
-tetracarboxylic acid, pyridine-2,3,5,6
-tetracarboxylic acid, etc. Among those listed above, () is particularly adipic acid, terephthalic acid, isophthalic acid, diphenyl ether-
4,4'-dicarboxylic acid, pyridine-2,6-dicarboxylic acid, sebacic acid, 4,4'-diphenylmethane-bis-trimellitic acid, 4,4'-
Diphenyl ether-bis-trimellitic acid, () pentane-1,2,5-tricarboxylic acid, cyclohexane-1,2,3-tricarboxylic acid, benzene-1,2,4-tricarboxylic acid, naphthalene- 1,4,5-tricarboxylic acid, naphthalene-2,3,6-tricarboxylic acid,
3,4,4'-biphenyltricarboxylic acid, 3,
4,4'-diphenyl ether tricarboxylic acid,
3,3',4-benzophenonetricarboxylic acid,
() as butane-1,2,3,4-tetracarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, naphthalene-2,3 , 6,7-tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 3,3',4,4'-diphenyl ethertetracarboxylic acid, 3,3',4,4 '-Diphenylsulfonetetracarboxylic acid or a mixture thereof is preferred from the viewpoint of chemical, thermal, electrical properties and processability of the polymer. Examples of the diisocyanate represented by the above general formula () include 1,2-diisocyanateethane, 1,2-diisocyanatepropane, tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene-1, 6-diisocyanate, nonamethylene-1,9-diisocyanate, decamethylene-
1,10-diisocyanate, ω,ω′-dipropyl ether diisocyanate, cyclohexane-
1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexahydrobiphenyl-4,4'-diisocyanate, hexahydrodiphenyl ether-4,4'-diisocyanate, phenylene-1,3-diisocyanate, phenylene -1,4-diisocyanate, toluylene-2,6-diisocyanate, toluylene-2,4-diisocyanate, 1-methoxybenzene-2,4-diisocyanate, 1-chlorophenylene diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate Isocyanate, paraxylylene diisocyanate,
diphenylmethane-4,4'-diisocyanate,
Diphenyl sulfide-4,4'-diisocyanate, diphenyl sulfone-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, diphenyl ether-3,4'-diisocyanate, diphenyl ketone-4, 4'-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 2,4'-
Biphenyl diisocyanate, 4,4'-biphenyl diisocyanate, 3,3'-dimethoxy-4,
Examples include 4'-biphenyl diisocyanate, anthraquinone-2,6-diisocyanate, triphenylmethane-4,4'-diisocyanate, and azobenzene-4,4'-diisocyanate. Among those listed above, hexamethylene-1,6-
Diisocyanate, dicyclohexylmethane
4,4'-diisocyanate, phenylene-1,3
-diisocyanate, phenylene-1,4-diisocyanate, toluylene-2,4-diisocyanate, toluylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, or this A mixture of the like is preferred from the economic point of view as well as the chemical, thermal, electrical properties and processability of the polymer. Furthermore, carbonates represented by the above general formulas () and () include, for example, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, francium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and hydrogen carbonate. Examples include rubidium, cesium hydrogen carbonate, and francium hydrogen carbonate, but lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, or mixtures thereof are particularly preferred in terms of catalytic effect. . Of course, so-called sesqui salts correspond to this mixture. The reaction of polyhydric carboxylic acid and diisocyanate according to the present invention can produce a polymer with a high degree of polymerization, which was not possible with conventional polymerization technology of polyhydric carboxylic acid and diisocyanate, as a compound that is inexpensive, stable, and extremely easy to handle. It can be produced extremely easily by coexisting an alkali metal salt of carbonic acid. In the method of the present invention, the polyhydric carboxylic acid and diisocyanate are mixed together in the coexistence of the alkali metal salt of carbonate, generally in an anhydrous organic polar solvent under a stream of anhydrous inert gas, such as nitrogen, or under reduced pressure. Below,
The polymerization reaction is carried out while removing by-product carbon dioxide gas. The polymerization reaction temperature ranges from room temperature to 250℃, especially 50℃.
℃ to 200℃ from the viewpoint of reaction rate and side reactions, and the polymerization reaction time is 1 hour to 20 hours, preferably 2 hours to 10 hours at the selected temperature, so that substantially no carbon dioxide gas is produced. The time period is chosen such that no occurrence of this phenomenon is observed. As the organic polar solvent, N,N-dimethylacetamide, N,N-diethylacetamide, N,N
- amide compounds such as dimethylformamide, N-methyl-2-pyrrolidone, hexamethylphosphoric triamide, or γ-butyrolactone;
Lactone compounds and sulfone compounds such as tetramethylene sulfone and diphenyl sulfone can be used. Furthermore, other solvents such as benzene, toluene, xylene,
A solvent that does not substantially react with carboxylic acid and isocyanate groups, such as cyclohexane, pentane, hexane, heptane, methylene chloride, tetrahydrofuran, cyclohexanone, and dioxane, may be added as appropriate. In the method of the present invention, the addition method, addition order, and addition timing of the polyhydric carboxylic acid, diisocyanate, and alkali metal salt of carbonic acid can be arbitrarily selected. The raw material monomer concentration at the start of polymerization is
A range of 50 g/solvent to 400 g/solvent is selected, and this concentration is selected depending on the reactivity of the raw material monomer and the solubility of the polymer in the polymerization solvent. Depending on the raw material monomer concentration at the start of the polymerization reaction, it is preferable to add the solvent continuously or discontinuously to the extent that stirring is not hindered due to thickening of the system during polymerization or addition of raw materials. . The molar ratio of diisocyanate/polycarboxylic acid in this polymerization reaction is 0.7 to 1.30 from the viewpoint of reducing the possibility of forming a network structure in the resulting polymer.
, preferably from 0.90 to 1.15, and the amount of the coexisting alkali metal salt of carbonate is preferably from 0.5 to 20 mol %, preferably from 1 to 10 mol %, based on the polyhydric carboxylic acid. The method of the present invention will be explained below with reference to examples, but the present invention is of course not limited to these examples. Note that the logarithmic viscosity value (ηinh) shown in the examples is a value measured according to the following formula. ηinh=ln(t/t _p )/C t _p : Flow time of the solvent using an Ubbelohde viscometer t : Flow time of a diluted polymer solution using an Ubbelohde viscometer C : Polymer dissolved in 100 ml of solvent Number of grams In the examples, the values measured at a temperature of 30°C after dissolving 0.1 g of polymer in 100 ml of concentrated sulfuric acid are described. Furthermore, the meanings of the abbreviations used in the examples are shown below. TDI65/35: Toluylene-2,4-diisocyanate/toluylene-2,6-diisocyanate (molar ratio = 65:35) TDI80/20: Toluylene-2,4-diisocyanate/toluylene-2,6-diisocyanate (molar ratio = 80:20) TDI100: Toluylene-2,4-diisocyanate MDI: Diphenylmethane-4,4'-diisocyanate HMDI: Hexamethylene-1,6-diisocyanate DPDI: Diphenyl ether-4,4'-diisocyanate IPA: Isophthalic acid TPA : Terephthalic acid TMA: Trimellitic acid BTA: Butane tetracarboxylic acid PMA: Pyromellitic acid TEDA: Triethylenediamine SO: Sodium oleate SM: Sodium methoxide CN: Cobalt naphthenate Pre-stirring: acid, solvent, alkali metal salt of carbonate and 80
Simultaneous stirring for 1 hour at °C: Charge acid, isocyanate, solvent, and alkali metal salt of carbonate at the same time. Example 1 IPA24.41 was placed in a 500 ml separable flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet.
g (0.1469 mol), lithium carbonate 0.2556 g (3.45×
10 ⁻³ mol) and anhydrous N-methyl-2-pyrrolidone
260ml was charged and sealed with dry nitrogen. This flask was heated in an oil bath, and the contents were heated and stirred at 80°C for 1 hour to form a homogeneous solution free of insoluble matter, and then cooled to 50°C. Add 27.63g of TDI80/20 to the resulting homogeneous solution.
(0.1586 mol) was added, heated again in an oil bath, and the contents were heated and stirred at 140°C for 4 hours to obtain a viscous brown reaction liquid. This reaction solution was poured into 1040 ml of methanol that was being stirred vigorously to precipitate the polymer, which was then thoroughly washed with methanol and dried at 150°C under reduced pressure for 3 hours to obtain 33.35 g of pale yellow powder. Ta. The logarithmic viscosity of this polymer was 1.69. Comparative Example 1 24.40 g of IPA was placed in the same reactor as Example 1.
(0.1469 mol), anhydrous N-methyl-2-pyrrolidone
260 ml and 27.62 g (0.1586 mol) of TDI80/20 were charged and sealed with dry nitrogen. This flask was heated in an oil bath and the contents were heated and stirred at 140°C for 4 hours to obtain a brown reaction liquid with no viscosity. This reaction solution was treated in the same manner as in Example 1 to produce a pale yellow powder.
26.68g was obtained. The logarithmic viscosity of this polymer is 0.50
It was hot. Examples 2 to 17, Comparative Examples 2 to 13 Tables 1, 2, 3, 4. Comparative Example 14 The same apparatus and method as in Example 15 were used, except that sodium methoxide was used instead of sodium carbonate as a catalyst, using monomers and catalyst amounts having substantially the same molar relationship as in Example 15 as described below. Polymerized with i.e. 0.0799g of sodium methoxide
(0.00148 mol), TMA 15.50 g (0.0738 mol), anhydrous N-methyl-2-pyrrolidone 260 ml and TDI-
65/35 9.074g (0.0521mol) MDI6.526g
(0.0261 mol) was charged, and the contents were heated at 140°C for 6 hours to react. The obtained reaction solution was treated in the same manner as in Example 1, and the logarithmic viscosity of the polymer obtained was 0.45.

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Claims (1)

[Scope of Claims] 1 At least one dicarboxylic acid, tricarboxylic acid or tetracarboxylic acid represented by the general formula (), () or () and at least one diisocyanate represented by the general formula (), In the production of a polyamide containing one or more repeating units represented by the formula (), () or (), it is characterized in that it is produced in the coexistence of at least one compound represented by the general formula () or (). A method for producing polyamide. R ¹ (COOH) ₂ () R ² (COOH) ₃ () R ³ (COOH) ₄ () R ⁴ (NCO) ₂ () [−CO−R ¹ −CONH−R ⁴ −NH]− () [ −CO−R ² (COOH)−CONH−R ⁴ −NH〕− () [−CO−R ³ (COOH) ₂ −CONH−R ⁴ −NH]−
() M ₂ CO ₃ () MHCO ₃ () However, in the above formula, R ^{1 to 4} and M mean the following. R ¹ : A divalent group containing at least two carbon atoms, or a group in which these groups are further substituted with a group or atom that does not substantially react with both a carboxyl group and an isocyanate group, and the above-mentioned During the ceremony
The two carboxyl groups bonded to R ¹ are bonded to two different carbon atoms contained in R ¹ . R ² : A trivalent group containing at least 3 carbon atoms, or a group in which these groups are further substituted with a group or atom that does not substantially react with both a carboxyl group and an isocyanate group, and the above-mentioned During the ceremony
The three carboxyl groups bonded to R ² are each bonded to three different carbon atoms contained in R ² . R ³ : A tetravalent group containing at least 4 carbon atoms, or a group in which such a group is further substituted with a group or atom that does not substantially react with both a carboxyl group and an isocyanate group, and the above-mentioned During the ceremony
The four carboxyl groups bonded to R ³ are each bonded to four different carbon atoms contained in R ³ . R ⁴ : A divalent group containing at least two carbon atoms, or a group in which these groups are further substituted with a group or atom that does not substantially react with both carboxyl groups and isocyanate groups, and the above-mentioned During the ceremony
The two isocyanate groups bonded to R ⁴ are each bonded to two different carbon atoms contained in R ⁴ . M: Alkali metal belonging to group A of the periodic table