JP2849001B2 - Carbodiimide copolymer and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a carbodiimide-based crocodile containing a carbodiimide copolymer having excellent solution storage stability.
And a method for producing the same.

[0002]

2. Description of the Related Art Generally, a high molecular weight aromatic polycarbodiimide resin is known as a resin having high heat resistance (T.
W. Campbell, KCSmeltz, J. Org. Chem., 28, 2069 (1963).
However, it has a drawback that it is hardly soluble in various solvents and has poor heat fluidity, so that it is difficult to perform a practical molding process while having excellent heat resistance. In addition, the document includes 2,4-
During the synthesis of carbodiimide from tolylene diisocyanate, there is a description of a method for producing a solvent-soluble polycarbodiimide by adding an alcohol and sealing the terminal in the form of a carbamate, but the heat resistance of the carbamate is poor, practical Was not.

According to J. Appl. Pol. Sci., Vol. 21, 1999 [1977] and JP-A-51-61599, a specific proportion of diphenylmethane-4,4 'has been proposed in order to improve the above problem. -Diisocyanate and an organic monoisocyanate as a molecular weight controlling agent, in an inert organic solvent, by reacting in the presence of a carbodiimidization catalyst, can be isolated as a powder, and a polycarbodiimide having fluidity under heat and pressure. We have found a manufacturing method. However, since it is difficult to dissolve in various solvents at a high concentration, it cannot be used as a practical varnish (solution) as a raw material for a laminate.

In recent years, according to JP-A-63-161031, a polycarbodiimide varnish (solution) is obtained by adding a small amount of monoisocyanate to tolylene diisocyanate and polymerizing in tetrachloroethylene. Thus, although a thermosetting film is produced, there is a problem in the stability of the solution, and there is a drawback that the amount and concentration of a solvent to be used are limited and the versatility is lacking.

On the other hand, Japanese Patent Application Laid-Open No. 2-292316 proposes a method for producing a high molecular weight polycarbodiimide solution, and describes that a high molecular weight polycarbodiimide solution of 10% by weight or less is stable for 3 weeks. At a low concentration of less than 10% by weight, more than 90% of the varnish is a solvent, so the varnish is not economical to move and store, and the solvent is not easily removed. Poor and not practical.

In the above prior art, a method for producing a varnish having a high concentration and a solution storage stability has not been found yet.
Although there is a description of the stability to a specific solvent, it is not general-purpose. For example, even if it is stable with tetrachloroethylene, it is often insoluble in toluene, which is more commonly used as a varnish solvent, and no general-purpose index was found.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a carbodiimide polymer which is dissolved in an organic solvent at a high concentration without impairing the excellent heat resistance of the carbodiimide bond and which has excellent storage stability in a solution. Carbodiimide containing coalescence
An object of the present invention is to provide a system varnish and a method for producing the same.

[0008]

Means for Solving the Problems The present inventors diligently studied the above-mentioned problems and arrived at the present invention. That is, the present invention is a group 95 having a structural unit represented by (1) the following equation (1) based on 5-95 equivalents unit having the structural unit represented by (Formula 2) and the following formula (2) (Formula 2) ~ 5 equivalent parts,
A carbodiimide copolymer in which the terminal of the polymer molecule is blocked with an aromatic group and the weight average molecular weight is 10,000 or less
A carbodiimide-based varnish comprising :

[0009]

Embedded image (2) The aromatic group at the molecular terminal of the polymer is a phenyl group, an ortho-tolyl group, a meta-tolyl group, a para-tolyl group, a dimethylphenyl group, a chlorophenyl group, a trifluoromethylphenyl group, a naphthyl group, an isopropylphenyl group. And the carbodii according to (1), which is at least one member selected from the group consisting of
Bromide based varnish for (3) 5 to 95 per 100 equivalents of 2,4-tolylene diisocyanate and 95 to 5 diisocyanate component containing equivalents of 2,6-tolylene diisocyanate in equivalent unit, 10 to 50 An equivalent part of an aromatic monoisocyanate is heated and polymerized at a temperature of 80 ° C. or more in an aprotic organic solvent in an amount of 1 to 5 times the total amount of the diisocyanate component in the presence of a carbodiimidization catalyst ( 1) a carbodiimide method for producing varnish according, (4) aprotic organic solvent, toluene, xylene, is at least one selected from the group consisting of tetrachlorethylene and dioxane (3) carbodiimide according
A varnish production method, (5) the aromatic monoisocyanate is phenyl isocyanate, ortho-tolyl isocyanate, meta-tolyl isocyanate, para-tolyl isocyanate, dimethylphenyl isocyanate, chlorophenylisocyanate, trifluoromethylphenylisocyanate,
(3) The method for producing a carbodiimide-based varnish according to (3), which is at least one selected from the group consisting of naphthyl isocyanate, isopropylphenyl isocyanate, and diisopropylphenyl isocyanate.

[0010]

The carbodiimide copolymer of the present invention comprises 2,
A group having a structural unit represented by the formula (1) derived from 4-tolylene diisocyanate (hereinafter abbreviated as 2,4-TDI);
Abbreviated as 6-TDI), the self-crosslinking temperature of the carbodiimide bond hardly decreases as the composition ratio of the components becomes smaller as the component ratio becomes smaller. Therefore, by appropriately selecting the composition ratio of the components, it is possible to obtain a carbodiimide copolymer having desired fluidity during heating and a stable melting range. Furthermore, since the polymer terminal is sealed with an aromatic group and the molecular weight is regulated, a carbodiimide copolymer having a desired viscosity can be obtained as a solution by appropriately selecting the molecular weight.

The carbodiimide copolymer of the present invention comprises benzene, toluene, xylene, perchrene, dioxane,
Dimethylformamide, dimethylacetamide, N-
Dissolves well in versatile solvents such as methylpyrrolidone and more than 15% by weight, especially in poorly soluble toluene solvents, and does not gel at room temperature, and has excellent solution storage stability. Yes, it can be stored in solution without gelling for at least one month or longer, usually three months or longer. Further, a solution containing 15% by weight or more of the carbodiimide copolymer of the present invention in an aprotic organic solvent such as toluene, xylene, perchylene, or dioxane can be stored at a predetermined concentration, and can be appropriately diluted according to the intended use. it can. As described above, the carbodiimide copolymer of the present invention overcomes the drawback that the conventional polycarbodiide has a high concentration and poor solution storage stability, and is suitable for producing various molded articles such as laminates and films. Is made possible.

Hereinafter, the configuration will be described in detail. 2,4-TDI and 2,6 which can be used in the method of the invention
-TDI can be used as a composition ratio of a predetermined component as it is or by mixing a commercially available product as it is.

In the method of the present invention, the proportions of 2,4-TDI and 2,6-TDI used are 5 to 95 mol parts of 2,4-TDI and 2,6-TDI when the total amount is 100 mol parts.
It is preferable to use 95 to 5 mol parts of DI, and furthermore, 60 to 90 mol parts of 2,4-TDI and 2,6-TD
It is more preferable to use I40 to 10 mol parts. In this case, a higher concentration solution containing 30% by weight or more of the carbodiimide copolymer can be obtained, and a commercially available inexpensive TDI mixture can be used as a raw material as it is. Therefore, it is more useful as an industrial production method. When 2,4-TDI or 2,6-TDI is used in an amount of 95 mol parts or more, it is liable to precipitate in the polymerization solution, and a stable high-concentration solution cannot be obtained, which is not practical.

In this method, various aromatic monoisocyanates can be used as a molecular weight controlling agent. As the organic monoisocyanate, phenyl isocyanate,
(Ortho, meta, para) -tolyl isocyanate, dimethylphenyl isocyanate, chlorophenyl isocyanate, trifluoromethylphenyl isocyanate,
Examples include naphthyl isocyanate, isopropylphenyl isocyanate, diisopropylphenyl isocyanate and the like. In the method of the present invention, it is particularly desirable to use phenyl isocyanate, which is easily available industrially. The amount of the aromatic monoisocyanate, which is a molecular weight controlling agent, can be used in an amount of 10 to 50 mol parts per 100 mol parts of TDI . If the amount is less than 10 mol parts, the degree of polymerization is too high and it is difficult to dissolve in a solvent, and the storage stability of the solution is deteriorated. If it exceeds 50 parts by mole, the isocyanate partially remains unreacted, and a large amount of diphenylcarbodiimide, which is a by-product from phenylisocyanate, is produced, so that only polycarbodiimide having poor heat resistance can be obtained.

Various catalysts can be used as a catalyst for promoting the carbodiimidation of isocyanate. Examples of the catalyst include 1-phenyl-2-phospholene-1-oxide and 3-methyl-1-phenyl-2-phospholene-1-oxide. Oxide, 1-
Phenyl-2-phospholene-1-sulfide, 1-ethyl-2-phospholene-1-oxide, 1-ethyl-3-
Methyl-2-phospholene-1-oxide and their corresponding isomers, 3-phospholenes, are preferred. The amount of catalyst can be used between 0.01 and 1% based on the total amount of isocyanate.

The aprotic organic solvent for polymerization that can be used in the method of the present invention includes aromatic hydrocarbon solvents such as benzene, toluene, ethylbenzene, cumene, and xylene; halogenated hydrocarbon solvents such as tricrene and perchrene; Dioxane, ether solvents such as diglyme, and other N-methylpyrrolidone, dimethylacetamide, dimethylformamide, dimethylimidazolidinone, and the like, but the boiling point of the solvent and the reaction temperature, when considering the practicality of the polymerization solution, toluene It is preferred to use

The polymerization is preferably carried out at a temperature near the boiling point of the aprotic organic solvent to be used.
Temperatures in the range 0 ° C. to 150 ° C., especially about 100 ° C. to 1 ° C.
It is more preferable to carry out the reaction at a temperature in the range of 50 ° C. in terms of shortening the reaction time and obtaining a copolymer having a narrow molecular weight distribution. When the polymerization is carried out at a temperature lower than 80 ° C., the isocyanate does not completely react and remains, thereby impairing the storage stability of the polymerization solution. On the other hand, when polymerization is carried out at a temperature exceeding 150 ° C., a side reaction of thermal crosslinking occurs, and gelation may occur. At the end of the polymerization reaction time, sample the polymerization solution,
IR analysis is performed to determine that the residual isocyanate is below 0.5%. When the residual isocyanate content is 0.5% or more, gelation during storage of the solution is promoted, and storage stability is impaired.

The carbodiimide copolymer obtained in the method of the present invention is used as a varnish as a polymerization solution.
Further, if necessary, the solvent can be directly removed under reduced pressure at 60 ° C. or lower, or it can be precipitated and isolated in a saturated hydrocarbon poor solvent such as hexane and heptane for use. In using the carbodiimide copolymer of the present invention, additives such as a curing agent such as an active hydrogen compound and a multiple bond compound, a filler such as carbon fiber and glass fiber, and a diluting solvent such as ethyl acetate and methyl ethyl ketone are mixed. You may.

An embodiment of the method of the present invention is as follows. 2,4-TDI, 2,6-TDI, an aromatic monoisocyanate, and an aprotic organic solvent are charged to a polymerization vessel. After stirring to form a homogeneous solution, a carbodiimidization catalyst dissolved in an aprotic organic solvent is added, the temperature is raised from 60 ° C to 150 ° C, and polymerization is performed at this temperature for 3 hours to 8 hours. And cooling to room temperature to obtain a carbodiimide copolymer solution. The carbodiimide copolymer thus obtained is used as a varnish in a solution. If necessary, the solvent is removed under reduced pressure at 60 ° C. or lower before use. This carbodiimide copolymer has a molecular weight of about 1,000 to about 10,000, has a 5% thermal decomposition temperature of 400 ° C. or more, dissolves in toluene at 15% by weight or more, and does not gel for more than one month at room temperature. And a varnish, a laminate, a film, a composite agent,
A carbodiimide copolymer suitable for producing various molded products such as a fiber treating agent can be obtained.

[0021]

Next, an embodiment of the present invention will be described in more detail. However, the present invention is not limited to these examples. The analysis and physical properties of the copolymers and solutions obtained in Examples and Comparative Examples were measured by the following methods.

Average molecular weight and molecular weight distribution: The copolymer solution was diluted with N-methylpyrrolidone, and the molecular weight distribution curve was measured using GPC.
The weight average molecular weight and molecular weight distribution were obtained by the standard. Solid content concentration: The copolymer solution was thinly spread on a glass petri dish, dried at 130 ° C. under a nitrogen stream until the weight became constant, and the solvent was removed. Then, the solid content was weighed and the concentration was converted. 5% decomposition temperature: The copolymer solution is spread thinly on a glass Petri dish, dried at 130 ° C. to remove the solvent, and then heated in air using a thermogravimetric analyzer (TGA) at a temperature increasing rate of 10 ° C.
At / min, the 5% weight loss temperature of the polymer was measured. Toluene solution storage stability: A 15% by weight toluene solution of the copolymer is placed in a transparent glass bottle and placed in a dark room temperature (25%).
C), and the solution was shaken periodically to check for gelation and change in appearance. Polymerization solution storage stability: The polymerization solution was placed in a transparent glass bottle, and the stability was examined in the same manner as the above test. Residual isocyanate test: A portion of the polymerization solution was sampled, sandwiched between rock salt plates, and the characteristic absorption of isocyanate was quantified using an infrared absorption spectrometer (IR). % (Detection limit 0.4%).

Example 1 In a 300 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, 22.4 g (0.128 mol) manufactured by Mitsui Toatsu Chemical Co., Ltd .; 2.20 g (0.0756 mol, T) of phenyl isocyanate (PhI)
14 mol parts per 100 mol parts of DI), 110 ml of dry toluene
Was charged into a nitrogen atmosphere and uniformly dissolved with stirring. Next, a 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent was used.
0.0913 g (0.000475 mol, 0.37% / TDI) was added, and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Internal temperature is 11
After reaching 0 ° C., polymerization was carried out for 3.5 hours. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. No residual isocyanate was detected in the solution
The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 15 Average molecular weight (Mw) 3000 Molecular weight distribution (Mw / Mn) 2.3 5% decomposition temperature (° C) 460 Solution stability Toluene solution storage Both stability and storage stability of polymerization solution did not gel for 3 months. The result was obtained.

Comparative Example 1 Example 1 was repeated except that phenyl isocyanate was not added.
As a result of the reaction, gelation occurred during the polymerization, and stirring became impossible.

[0025]

Comparative Example 2 A polymer was obtained in the same manner as in Example 1 except that 2,4-TDI was used instead of the TDI mixture. As a result, a clear carbodiimide copolymer solution was obtained. Some of the copolymer precipitated out of solution.

Example 2 In a 500 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, 92.1 g (0.529 mol), manufactured by Mitsui Toatsu Chemicals Co., Ltd., 9.00 g (0.0756 mol, 14 mol parts per 100 mol parts of TDI) of phenyl isocyanate and 202 ml of dry toluene were charged into a nitrogen atmosphere and stirred. While uniformly dissolving. Next, 0.359 g (0.059 g) of a 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 5 ml of the same solvent as the polymerization solvent was used.
0187 mol, 0.35% / TDI) and the internal temperature was reduced while stirring.
The temperature was raised to 110 ° C. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 3.5 hours after the internal temperature reached 110 ° C. After the polymerization, cool to room temperature,
A clear carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. Analysis of the carbodiimide copolymer and measurement of physical properties showed that the solid content (%) 30 average molecular weight (Mw) 3200 molecular weight distribution (Mw / Mn) 3.1 5% decomposition temperature (° C) 450 solution stability toluene solution storage Both stability and storage stability of polymerization solution did not gel for 3 months. The result was obtained.

Example 3 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, 22.1 g (0.127 mol) manufactured by Mitsui Toatsu Chemical Co., Ltd., 2.13 g (0.0179 mol, 14 mol parts based on 100 mol parts of TDI) and 48 ml of dry toluene were charged into a nitrogen atmosphere. It dissolved uniformly while stirring. Next, 0.0122 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent (0.002 g)
0063 mol, 0.05% / TDI), and the internal temperature was reduced while stirring.
The temperature was raised to 110 ° C. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 7.1 hours after the internal temperature reached 110 ° C. After the polymerization, cool to room temperature,
A clear carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 30 Average molecular weight (Mw) 3900 Molecular weight distribution (Mw / Mn) 3.5 5% decomposition temperature (° C) 450 Solution stability Toluene solution storage Both stability and storage stability of polymerization solution did not gel for 3 months. The result was obtained.

Example 4 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
2, 22.8 g (0.131 mol) of Mitsui Toatsu Chemical Co., Ltd., 3.15 g (0.0264 mol, 20 mol parts based on 100 mol parts of TDI) and 52 ml of dry toluene were charged into a nitrogen atmosphere. It dissolved uniformly while stirring. Next, 0.0128 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent (0.
(Mol, 0.05% / TDI), and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 7 hours after the internal temperature reached 110 ° C. After the polymerization, cool to room temperature,
A clear carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 30 Average molecular weight (Mw) 2800 Molecular weight distribution (Mw / Mn) 3.0 5% decomposition temperature (° C) 440 Solution stability Toluene solution storage Both stability and storage stability of polymerization solution did not gel for 3 months. The result was obtained.

Example 5 In a 500 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 65 mol of 2,4-TDI and 2,2
6-TDI 35 mol part mixture (trade name; TDI 6
5, 91.3 g (0.524 mol) of Mitsui Toatsu Chemical Co., Ltd., 8.91 g (0.0748 mol, 14 mol parts based on 100 mol parts of TDI) of phenyl isocyanate and 200 ml of dry toluene were charged in a nitrogen atmosphere. And homogeneously dissolved with stirring. next,
0.350 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 6 ml of the same solvent as the polymerization solvent
(0.00182 mol, 0.35% / TDI), and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 7 hours after the internal temperature reached 110 ° C. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. No residual isocyanate was detected in the solution. Analysis of the carbodiimide copolymer and measurement of physical properties showed that the solid content (%) 30 average molecular weight (Mw) 3100 molecular weight distribution (Mw / Mn) 3.3 5% decomposition temperature (° C) 440 solution stability toluene solution storage Both stability and storage stability of polymerization solution did not gel for 3 months. The result was obtained.

Example 6 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, 22.5 g (0.129 mol) manufactured by Mitsui Toatsu Chemicals Co., Ltd., 2.17 g (0.01822 mol, 14 mol parts based on 100 mol parts of TDI) and 49 ml of dry perchrene were charged in a nitrogen atmosphere. And homogeneously dissolved with stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent was used.
-Phenyl-2-phospholene-2-oxide catalyst 0.0125
g (0.000065 mol, 0.05% / TDI) was added, and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 7 hours after the internal temperature reached 110 ° C. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A small amount of residual isocyanate was detected in the solution, but it was less than 0.4%. The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 19 Average molecular weight (Mw) 2300 Molecular weight distribution (Mw / Mn) 2.4 5% decomposition temperature (° C) 435 Solution stability Toluene solution storage No gelation for 1 month in both stability and storage stability of polymerization solution. The result was obtained.

Example 7 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, 25.4 g (0.129 mol) manufactured by Mitsui Toatsu Chemical Co., Ltd., 2.49 g (0.0209 mol, 14 mol parts based on 100 mol parts of TDI) and 40 ml of dry perchrene were charged into a nitrogen atmosphere. It dissolved uniformly while stirring. next,
0.014 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent (0.
(Mol, 0.05% / TDI), and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was performed for 7.5 hours after the internal temperature reached 110 ° C. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but was less than 0.4%. The carbodiimide copolymer was analyzed and its physical properties were measured. Solids (%) 25 Average molecular weight (Mw) 3200 Molecular weight distribution (Mw / Mn) 2.9 5% Decomposition temperature (° C) 435 Solution stability Toluene solution storage No gelation for 1 month in both stability and storage stability of polymerization solution. The result was obtained.

Comparative Example 3 A transparent carbodiimide copolymer solution was obtained in the same manner as in Example 7 except that phenyl isocyanate was not added, but the polymerization solution gelled within 3 days. .

Example 8 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, manufactured by Mitsui Toatsu Chemicals, Inc.) 19.11 g (0.110 mol), phenyl isocyanate 6.55 g (0.0550 mol, TDI 100
50 mol parts per mol part) and 51 ml of dry perchrene were charged in a nitrogen atmosphere and uniformly dissolved with stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent was used.
-Phenyl-2-phospholene-1-oxide catalyst 0.0747
g (0.000389 mol, 0.35% / TDI) was added, and the internal temperature was raised to 110 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. After the internal temperature reached 110 ° C, polymerization was carried out for 3.5 hours. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A small amount of residual isocyanate was detected in the solution, but 0.4%
It was below. The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 25 Average molecular weight (Mw) 1300 Molecular weight distribution (Mw / Mn) 2.0 5% Decomposition temperature (° C) 420 Solution stability Toluene solution storage No gelation for 1 month in both stability and storage stability of polymerization solution. The result was obtained.

Example 10 In a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser, 80 mol of 2,4-TDI and 2,2
6-TDI 20 mol part mixture (trade name; TDI 8
0, manufactured by Mitsui Toatsu Chemical Co., Ltd.), 23.1 g (0.133 mol), phenyl isocyanate 2.37 g (0.0199 mol, 15 mol parts based on 100 mol parts of TDI), and 51 ml of dry dioxane were charged in a nitrogen atmosphere. And homogeneously dissolved with stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent was used.
-Phenyl-2-phospholene-1-oxide catalyst 0.091
g (0.00047 mol, 0.36% / TDI) was added, and the internal temperature was raised to 100 ° C. while stirring. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 5 hours after the internal temperature reached 100 ° C. After completion of the polymerization, the mixture was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but was less than 0.4%. Analysis of this carbodiimide copolymer and measurement of its physical properties showed that the solid content (%) 27 average molecular weight (Mw) 3300 molecular weight distribution (Mw / Mn) 3.0 5% decomposition temperature (° C) 430 solution stability toluene solution storage No gelation for 1 month in both stability and storage stability of polymerization solution. The result was obtained.

Example 11 In a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser, 80 mol of 2,4-TDI and 2,2 TDI were added.
6-TDI 20 mol part mixture (trade name; TDI 8
0, 22.1 g (0.127 mol) manufactured by Mitsui Toatsu Chemical Co., Ltd., 5.11 g (0.0429 mol, 34 mol parts based on 100 mol parts of TDI) and 54 ml of dry xylene were charged into a nitrogen atmosphere. It dissolved uniformly while stirring. next,
0.087 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent (0.087 g)
0045 mol, 0.36% / TDI), and the internal temperature was reduced while stirring.
The temperature was raised to 110 ° C. As the temperature rose, the generation of carbon dioxide increased, and the generation of carbon dioxide was observed particularly intensely when the internal temperature exceeded 80 ° C. Polymerization was carried out for 3.5 hours after the internal temperature reached 110 ° C. After the polymerization, cool to room temperature,
A clear carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. The carbodiimide copolymer was analyzed and its physical properties were measured. Solid content (%) 29 Average molecular weight (Mw) 1900 Molecular weight distribution (Mw / Mn) 3.0 5% decomposition temperature (° C) 435 Solution stability Toluene solution storage No gelation for 1 month in both stability and storage stability of polymerization solution. The result was obtained.

[0037]

The carbodiimide copolymer produced by the method of the present invention overcomes the drawback that the storage stability of a polycarbodiimide obtained by a conventional method in a solution, particularly the storage stability at a high concentration, is poor. The carbodiimide is industrially capable of producing a carbodiimide copolymer in a large amount by a simple operation without losing its excellent heat resistance, and its industrial utility value is extremely large.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-161031 (JP, A) JP-A-52-69988 (JP, A) JP-A-62-1714 (JP, A) JP-A-53-1769 47499 (JP, A) JP-A-5-9252 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 18/00-18/87 C08G 73/00 C09D 179/00- 179/08 C09D 175/00-175/16

Claims (5)

(57) [Claims] 1 to 5 parts by weight of a group having a structural unit represented by the following formula (1) (formula 1) and 95 to 5 parts by weight of a group having a structural unit represented by the following formula (2) A carbodiimide copolymer having a polymer molecule terminal terminated with an aromatic group and having a weight average molecular weight of 10,000 or less.
A carbodiimide-based varnish comprising a coalescence . Embedded image 2. The polymer according to claim 1, wherein the aromatic groups at the molecular terminals of the polymer are phenyl, ortho-tolyl, meta-tolyl, para-tolyl, dimethylphenyl, chlorophenyl, trifluoromethylphenyl, naphthyl, isopropyl. 2. The cal according to claim 1, which is at least one member selected from the group consisting of a phenyl group and a diisopropylphenyl group.
Bodiimide varnish . 3. A total amount of diisocyanate component containing 5 to 95 equivalent parts of 2,4-tolylene diisocyanate and 95 to 5 equivalent parts of 2,6-tolylene diisocyanate.
100 equivalents to 10-50 equivalents of an aromatic monoisocyanate, in the presence of a carbodiimidization catalyst, in an aprotic organic solvent of 1 to 5 times the total amount of the diisocyanate component at a temperature of 80 ° C or higher. 2. The method for producing a carbodiimide-based varnish according to claim 1, wherein the polymerization is carried out by heating. 4. The carbodiy according to claim 3, wherein the aprotic organic solvent is at least one selected from the group consisting of toluene, xylene, perchrene and dioxane.
A method for producing a mid varnish . 5. The aromatic monoisocyanate is phenyl isocyanate, ortho-tolyl isocyanate, meta-tolyl isocyanate, para-tolyl isocyanate, dimethylphenyl isocyanate, chlorophenyl isocyanate, trifluoromethylphenylisocyanate, naphthyl isocyanate, isopropylphenylisocyanate and diisopropyl. The method for producing a carbodiimide-based varnish according to claim 3, which is at least one member selected from the group consisting of phenyl isocyanate.