JPH05310877A - Carbodiimide copolymer and its production - Google Patents

Abstract

PURPOSE:To produce a carbodiimide copolymer which is soluble in an org. solvent at a high concn. and gives a soln. with an excellent storage stability by thermally copolymerizing a specific diisocyanate component with an arom. monoisicyanate in the presence of a carbodiimidation catalyst in an org solvent. CONSTITUTION:The copolymer is produced by thermally copolymerizing 100 equivalents of a diisocyanate component comprising 5-95 equivalents of 2,4- tolylene diisocyanate and 95-5 equivalents of 2,6-tolylene diisocyanate with 10-50 equivalents of an arom. monoisocyanate in the presence of a carbodiimidation catalyst in an aprotic solvent of an amt. of 1-5 times the amt. of the diisocyanate component at 80 deg.C. The copolymer comprises 5-95 equivalent % structural units of formula I and 95-5 equivalent % structural units of formula II, has molecular ends blocked by arom. groups, and has a wt. average mol.wt. of at least 10,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 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, due to the drawbacks of being difficult to dissolve in various solvents and having poor heat fluidity, it was difficult to perform practical molding while having excellent heat resistance. Moreover, in the document, 2,4-
While synthesizing carbodiimide from tolylene diisocyanate, there is a description of a method for producing a solvent-soluble polycarbodiimide by adding an alcohol and sealing the end in the form of a carbamate, but the heat resistance of the carbamate is poor and practical. Was not.

According to the description of J. Appl. Polm. Sci., Vol. 21, 1999 [1977] and JP-A-51-61599, in order to improve the above problems, a specific proportion of diphenylmethane-4,4 '. -A diisocyanate and an organic monoisocyanate as a molecular weight control agent are reacted in an inert organic solvent in the presence of a carbodiimidization catalyst to be isolated as a powder, which is a polycarbodiimide which is fluid under heat and pressure. We are finding a manufacturing method. However, since it is difficult to dissolve in various solvents at a high concentration, it cannot be provided as a practical varnish (solution) such as a raw material for a laminated plate.

Recently, according to the description of JP-A-63-161031, a small amount of monoisocyanate is added to tolylene diisocyanate and polymerized in tetrachloroethylene to obtain a polycarbodiimide varnish (solution). Although a thermosetting film is produced, there is a problem in that the stability of the solution is problematic, and the amount and concentration of the solvent used is limited, resulting in lack of versatility.

On the other hand, Japanese Unexamined Patent Publication (Kokai) No. 2-292316 proposes a method for producing a high molecular weight polycarbodiimide solution, which 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 it is not economical to move and store the varnish, and it is not easy to remove the solvent. Poor and not practical.

[0006] In the above conventional technique, a method for producing a varnish having a high concentration and solution storage stability has not been found yet,
In addition, although there is a description of stability with respect 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 general as a varnish solvent, and a general-purpose index was not found.

[0007]

An object of the present invention is to dissolve a carbodiimide bond at a high concentration in an organic solvent without impairing the excellent heat resistance of the carbodiimide bond and to provide a carbodiimide polymer having excellent storage stability in a solution. An object of the present invention is to provide a united body and a manufacturing method thereof.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies on the above-mentioned problems and have reached the present invention. That is, the present invention includes (1) a group 5 to 95 equivalent parts having a structural unit represented by the following formula (1) (Chemical formula 3) and a group 95 having a structural unit represented by the following formula (2) (Chemical formula 3) Including ~ 5 equivalent parts,
A carbodiimide copolymer characterized in that a polymer molecule end is sealed with an aromatic group and a weight average molecular weight is 10,000 or less,

[0009]

[Chemical 3] (2) The aromatic group at the molecular end of the polymer is a phenyl group, ortho-tolyl group, meta-tolyl group, para-tolyl group, dimethylphenyl group, chlorophenyl group, trifluoromethylphenyl group, naphthyl group, isopropylphenyl group. And at least one selected from the group consisting of diisopropylphenyl groups, (3) 5 to 95 equivalent parts of 2,4-tolylene diisocyanate and 95 to 5 equivalent parts of 2. , 6-tolylene diisocyanate, relative to 100 parts by weight of the total amount of the diisocyanate component, 10 to 50 parts by weight of the aromatic monoisocyanate is added in an amount of 1 to 5 times the total amount of the diisocyanate component in the presence of the carbodiimidization catalyst. Characterized by heat-polymerizing in an aprotic organic solvent at a temperature of 80 ° C. or higher The method for producing a carbodiimide copolymer according to claim 1, (4) The carbodiimide copolymer according to claim 3, wherein the aprotic organic solvent is at least one selected from the group consisting of toluene, xylene, perkylene and dioxane. (5) Aromatic monoisocyanate is phenyl isocyanate, ortho-tolyl isocyanate, meta-tolyl isocyanate, para-tolyl isocyanate, dimethylphenyl isocyanate, chlorophenyl isocyanate, trifluoromethylphenyl isocyanate,
4. At least one selected from the group consisting of naphthyl isocyanate, isopropylphenyl isocyanate and diisopropylphenyl isocyanate.
5. Method for producing carbodiimide copolymer and (6) 5 to 95 equivalent parts of a group having a structural unit represented by the following formula (1) (chemical formula 4) and a structural unit represented by the following formula (2) (chemical formula 4) Including 95 to 5 equivalents of a group having
2. A carbodiimide-based varnish comprising the carbodiimide copolymer according to claim 1, wherein the polymer has a molecular terminal blocked with an aromatic group and a weight average molecular weight of 10,000 or less.

[0010]

[Chemical 4] Is.

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), and 2,6-tolylene diisocyanate (hereinafter 2,
6-TDI) and a group having a structural unit represented by the formula (2) derived from 6-TDI), and the self-crosslinking temperature of the carbodiimide bond hardly decreases even though the composition becomes smaller as the composition ratio of the components becomes smaller. Therefore, by appropriately selecting the composition ratio of the components, a carbodiimide copolymer having a desired fluidity during heating and a melt stability width can be obtained. 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, perkylene, dioxane,
Dimethylformamide, dimethylacetamide, N-
It is characterized by excellent solubility in a general-purpose solvent such as methylpyrrolidone, 15% by weight or more in a toluene solvent which is particularly difficult to dissolve, does not gel at room temperature, and has excellent solution storage stability. Yes, it can be stored in solution for at least 1 month or longer, usually 3 months or longer without gelation. 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, perkylene, or dioxane can be stored at a predetermined concentration, and can be appropriately diluted before use. it can. As described above, the carbodiimide copolymer of the present invention overcomes the disadvantage that the solution storage stability is poor at high concentrations of conventional polycarbodides, and is a varnish suitable for production of various molded products such as laminates and films. It is possible to provide.

The configuration will be described in detail below. 2,4-TDI and 2,6 which can be used in the method of the present invention
-TDI can be used as a composition ratio of predetermined components as it is or as a mixture of industrially easily available products.

In the method of the present invention, the proportions of 2,4-TDI and 2,6-TDI used are, when the total amount is 100 mol parts, 2,4-TDI 5 to 95 mol parts and 2,6-TDI.
It is preferable to use 95 to 5 parts by mol of DI, and further 60 to 90 parts by mol of 2,4-TDI and 2,6-TD.
It is more preferable to use I40 to 10 parts by mol, and in this case, a higher concentration solution containing 30% by weight or more of a carbodiimide copolymer can be obtained, and a commercially available inexpensive TDI mixture can be used as it is as a raw material. 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 parts by mole or more, precipitation tends to occur 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 the molecular weight control agent. As the organic monoisocyanate, phenyl isocyanate,
(Ortho, meta, para) -tolyl isocyanate, dimethylphenyl isocyanate, chlorophenyl isocyanate, trifluoromethylphenyl isocyanate,
Naphthyl isocyanate, isopropyl phenyl isocyanate, diisopropyl phenyl isocyanate, etc. can be illustrated. In the method of the present invention, the use of phenyl isocyanate is particularly desirable, and it is easily available industrially. The amount of the aromatic monoisocyanate used as the molecular weight control agent can be 10 to 50 parts by mol based on 100 parts by mol of MDI. If it is less than 10 parts by mole, the degree of polymerization is too high to make it difficult to dissolve in a solvent, and the storage stability of the solution becomes poor. If the amount exceeds 50 parts by mole, some of the isocyanate 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 the catalyst for promoting the carbodiimidization of isocyanate, but 1-phenyl-2-phospholen-1-oxide and 3-methyl-1-phenyl-2-phospholen-1- Oxide, 1-
Phenyl-2-phosphorene-1-sulfide, 1-ethyl-2-phosphorene-1-oxide, 1-ethyl-3-
Methyl-2-phospholen-1-oxide, the corresponding isomers thereof, and 3-phosphorenes are preferable. The catalyst amount can be used in the range of 0.01 to 1% based on the total amount of isocyanate.

The aprotic organic solvent for polymerization which can be used in the method of the present invention is an aromatic hydrocarbon solvent such as benzene, toluene, ethylbenzene, cumene or xylene, a halogenated hydrocarbon solvent such as trichlene or perkylene, or Dioxane, ether solvents such as diglyme, and other N-methylpyrrolidone, dimethylacetamide, dimethylformamide, dimethylimidazolidinone and the like, but when considering the boiling point of the solvent and the reaction temperature, the practicality of the polymerization solution, toluene Is preferably used.

The polymerization is preferably carried out at a temperature near the boiling point of the aprotic organic solvent used, specifically about 8
Temperatures in the range 0 ° C to 150 ° C, especially about 100 ° C to 1
It is more preferable to carry out the reaction at a temperature in the range of 50 ° C. from the viewpoint 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, impairing the storage stability of the polymerization solution. On the other hand, if the polymerization is carried out at a temperature higher than 150 ° C., a side reaction of thermal crosslinking may occur and gelation may occur. The end point of the reaction time of the polymerization, sampling the polymerization solution,
IR analysis is performed, and the point where the residual isocyanate falls below 0.5% is set. If the residual isocyanate content is 0.5% or more, gelation during solution storage is promoted and storage stability is impaired.

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

An embodiment of the method of the present invention is as follows. Charge 2,4-TDI, 2,6-TDI, aromatic monoisocyanate, aprotic organic solvent to a polymerization vessel. After stirring to form a uniform solution, a carbodiimidization catalyst dissolved in an aprotic organic solvent was added, the temperature was raised from 60 ° C to 150 ° C, and polymerization was carried out at this temperature for 3 to 8 hours. Then, it is cooled to room temperature to obtain a carbodiimide copolymer solution. The carbodiimide copolymer thus obtained is used as a varnish as 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 higher, dissolves 15% by weight or more in toluene, and does not gel at room temperature for one month or longer. As a varnish, a laminate, a film, a composite agent,
A carbodiimide copolymer suitable for production of various molded products such as a fiber treating agent can be obtained.

[0021]

EXAMPLES Next, examples of the present invention will be shown and described more specifically. However, the present invention is not limited to these examples. Further, the analysis and physical property values 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, the curve of the molecular weight distribution curve was measured using GPC, polystyrene,
The weight average molecular weight and the 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 a constant weight was obtained to remove the solvent, and then the solid content was weighed to calculate the concentration. 5% decomposition temperature: The copolymer solution was 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 heating rate of 10 ° C.
The 5% weight loss temperature of the polymer was measured in / min. Toluene solution storage stability: A 15 wt% toluene solution of the copolymer was placed in a transparent glass bottle and stored in the dark at room temperature (25
C.) and periodically shaken the solution, and examined for gelation and appearance change. Polymerization solution storage stability: The polymerization solution was placed in a transparent glass bottle and stability was examined in the same manner as in the above test. Residual isocyanate inspection: A part of the polymerization solution was sampled, sandwiched between rock salt plates, and the infrared absorption spectrum measuring device (IR) was used to quantify the characteristic absorption of isocyanate. % (Detection limit 0.4%).

Example 1 In a 300 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, manufactured by Mitsui Toatsu Chemicals, Inc. 22.4 g (0.128 mol), phenylisocyanate (PhI) 2.20 g (0.0756 mol, T)
14 mol parts to 100 mol parts of DI), 110 ml of dry toluene
Was charged in a nitrogen atmosphere and uniformly dissolved with stirring. Next, 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent
0.0913 g (0.000475 mol, 0.37% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. Inner temperature is 11
After reaching 0 ° C, polymerization was carried out for 3.5 hours. After completion of the polymerization, the solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. No residual isocyanate was detected in the solution
When this carbodiimide copolymer was analyzed and the 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 except that no phenyl isocyanate was added.
As a result of reacting in the same manner as above, gelation occurred during the polymerization and stirring became impossible.

Comparative Example 2 Phenylisocyanate was added to 100 parts by mole of TDI.
Polymerization was performed in the same manner as in Example 1 except that 5 parts by mole was used, and as a result, a transparent carbodiimide copolymer solution was obtained, but the polymerization solution gelled within 3 days.

Comparative Example 3 Polymerization was carried out in the same manner as in Example 1 except that 2,4-TDI was used instead of the TDI mixture, and as a result, a transparent carbodiimide copolymer solution was obtained, but the polymerization was carried out within 3 days. A portion of the copolymer precipitated out of solution.

Example 2 In a 500 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemicals Co., Ltd. 92.1 g (0.529 mol), phenylisocyanate 9.00 g (0.0756 mol, 14 mol parts to 100 mol parts of TDI), 202 ml of dry toluene were charged in a nitrogen atmosphere and stirred. While uniformly dissolving. Next, 0.359 g (0.03 g) of 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted with 5 ml of the same solvent as the polymerization solvent.
(0187 mol, 0.35% / TDI) was added and the internal temperature was adjusted while stirring.
The temperature was raised to 110 ° C. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. Polymerization was carried out for 3.5 hours after the internal temperature reached 110 ° C. After the completion of polymerization, cool to room temperature,
A transparent carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. Analysis of this carbodiimide copolymer and measurement of physical properties revealed that 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, a thermometer and a cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd. 22.1 g (0.127 mol), 2.13 g of phenyl isocyanate (0.0179 mol, 14 mol parts to 100 mol parts of TDI), 48 ml of dry toluene were charged in a nitrogen atmosphere, It was uniformly dissolved with stirring. Next, 0.0122 g (0.002 g) of 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted in 1 ml of the same solvent as the polymerization solvent
0063 mol, 0.05% / TDI) was added and the internal temperature was adjusted while stirring.
The temperature was raised to 110 ° C. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. After the internal temperature reached 110 ° C, polymerization was performed for 7.1 hours. After the completion of polymerization, cool to room temperature,
A transparent carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. When this carbodiimide copolymer was analyzed and the 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 80 parts by mole of 2,4-TDI and 2, in a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser.
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd.) 22.8 g (0.131 mol), phenylisocyanate 3.15 g (0.0264 mol, 20 mol parts to 100 mol parts of TDI), 52 ml of dry toluene were charged in a nitrogen atmosphere, It was uniformly dissolved with stirring. Next, 0.0128 g of 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted with 1 ml of the same solvent as the polymerization solvent (0.
000066 mol, 0.05% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. Polymerization was carried out for 7 hours after the internal temperature reached 110 ° C. After the completion of polymerization, cool to room temperature,
A transparent carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. When this carbodiimide copolymer was analyzed and the 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, a thermometer and a cooling condenser, 65 parts by mole of 2,4-TDI and 2,
A mixture of 35 parts by mol of 6-TDI (trade name: TDI 6
5. Mitsui Toatsu Chemicals Co., Ltd. 91.3 g (0.524 mol), phenylisocyanate 8.91 g (0.0748 mol, 14 mol parts to 100 mol parts of TDI), 200 ml of dry toluene were charged in a nitrogen atmosphere. , Dissolved uniformly while stirring. next,
0.350 g of 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted in 6 ml of the same solvent as the polymerization solvent
(0.00182 mol, 0.35% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently 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 solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. No residual isocyanate was detected in the solution. Analysis of this carbodiimide copolymer and measurement of physical properties revealed that 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 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd.) 22.5 g (0.129 mol), phenylisocyanate 2.17 g (0.01822 mol, 14 mol parts to 100 mol parts of TDI), dry Perkren 49 ml was charged in a nitrogen atmosphere. , Dissolved uniformly while stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent.
-Phenyl-2-phosphorene-2-oxide catalyst 0.0125
g (0.000065 mol, 0.05% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently 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 solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but it was 0.4% or less. When this carbodiimide copolymer was analyzed and the physical properties were measured, the 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 Both stability and storage stability of polymerization solution did not gel for 1 month. The result was obtained.

Example 7 In a 100 ml separable flask equipped with a stirrer, thermometer and cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd. 25.4 g (0.129 mol), phenylisocyanate 2.49 g (0.0209 mol, TDI 100 mol parts, 14 mol parts), dry Perkren 40 ml were charged in a nitrogen atmosphere, It was uniformly dissolved with stirring. next,
0.014 g of 3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted with 1 ml of the same solvent as the polymerization solvent (0.
000073 mol, 0.05% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. After the internal temperature reached 110 ° C, polymerization was performed for 7.5 hours. After completion of the polymerization, the solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but it was 0.4% or less. When this carbodiimide copolymer was analyzed and the physical properties were measured, solid content (%) 25 average molecular weight (Mw) 3200 molecular weight distribution (Mw / Mn) 2.9 5% decomposition temperature (° C) 435 solution stability toluene solution storage Both stability and storage stability of polymerization solution did not gel for 1 month. The result was obtained.

Comparative Example 4 Polymerization was carried out in the same manner as in Example 7 except that phenylisocyanate was not added. As a result, a transparent carbodiimide copolymer solution was obtained, but the polymerization solution gelled within 3 days. ..

Example 8 80 parts by mole of 2,4-TDI and 2, in a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser.
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, manufactured by Mitsui Toatsu Chemicals, Inc. 19.11 g (0.110 mol), phenylisocyanate 6.55 g (0.0550 mol, TDI 100)
(50 mol parts relative to the mol parts) and 51 ml of dried Percene were charged in a nitrogen atmosphere and uniformly dissolved while stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent.
-Phenyl-2-phosphorene-1-oxide catalyst 0.0747
g (0.000389 mol, 0.35% / TDI) was added, and the internal temperature was raised to 110 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. Polymerization was carried out for 3.5 hours after the internal temperature reached 110 ° C. After completion of the polymerization, the solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but 0.4%
It was below. When the carbodiimide copolymer was analyzed and the 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 Both stability and storage stability of polymerization solution did not gel for 1 month. The result was obtained.

Example 10 In a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd., 23.1 g (0.133 mol), phenylisocyanate 2.37 g (0.0199 mol, 15 mol parts to 100 mol parts of TDI), and dry dioxane 51 ml were charged in a nitrogen atmosphere. , Dissolved uniformly while stirring. Next, 3-methyl-1 diluted in 1 ml of the same solvent as the polymerization solvent.
-Phenyl-2-phosphorene-1-oxide catalyst 0.091
g (0.00047 mol, 0.36% / TDI) was added, and the internal temperature was raised to 100 ° C. with stirring. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently 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 solution was cooled to room temperature to obtain a transparent carbodiimide copolymer solution. A trace amount of residual isocyanate was detected in the solution, but it was 0.4% or less. When this carbodiimide copolymer was analyzed and the physical properties were measured, solid content (%) 27 Average molecular weight (Mw) 3300 Molecular weight distribution (Mw / Mn) 3.0 5% Decomposition temperature (° C) 430 Solution stability Storage in toluene solution Both stability and storage stability of polymerization solution did not gel for 1 month. The result was obtained.

Example 11 In a 100 ml separable flask equipped with a stirrer, a thermometer and a cooling condenser, 80 parts by mole of 2,4-TDI and 2,
A mixture of 20 parts by mol of 6-TDI (trade name; TDI 8
0, Mitsui Toatsu Chemical Co., Ltd.) 22.1 g (0.127 mol), phenylisocyanate 5.11 g (0.0429 mol, 34 mol parts to 100 mol parts of TDI), 54 ml of dry xylene were charged in a nitrogen atmosphere, It was uniformly dissolved with stirring. next,
3-methyl-1-phenyl-2-phosphorene-1-oxide catalyst diluted with 1 ml of the same solvent as the polymerization solvent 0.087 g (0.0
(0045 mol, 0.36% / TDI) was added and the internal temperature was increased while stirring.
The temperature was raised to 110 ° C. The generation of carbon dioxide increased as the temperature increased, and carbon dioxide generation was observed particularly violently when the internal temperature exceeded 80 ° C. After the internal temperature reached 110 ° C, polymerization was performed for 3.5 hours. After the completion of polymerization, cool to room temperature,
A transparent carbodiimide copolymer solution was obtained. No residual isocyanate was detected in the solution. When the carbodiimide copolymer was analyzed and the 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 Both stability and storage stability of polymerization solution did not gel for 1 month. The result was obtained.

[0037]

INDUSTRIAL APPLICABILITY The carbodiimide copolymer produced by the method of the present invention overcomes the drawback that the storage stability of the polycarbodiimide obtained by the conventional method in a solution, particularly the storage stability at a high concentration, is poor. The carbodiimide enables industrial production in which a large amount of carbodiimide copolymer can be produced by a simple operation without losing the excellent heat resistance of carbodiimide, and has an extremely great industrial utility value.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akihiro Yamaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (6)

[Claims] 1. A group of 5 to 95 equivalent parts having a structural unit represented by the following formula (1) (chemical formula 1) and a group of 95 to 5 equivalent parts having a structural unit represented by the following formula (2) (chemical formula 1). A carbodiimide copolymer characterized by containing a polymer having a terminal of a polymer molecule sealed with an aromatic group and having a weight average molecular weight of 10,000 or less. [Chemical 1] 2. The aromatic group at the molecular end of the polymer is a phenyl group, ortho-tolyl group, meta-tolyl group, para-tolyl group, dimethylphenyl group, chlorophenyl group, trifluoromethylphenyl group, naphthyl group, isopropyl group. The carbodiimide copolymer according to claim 1, which is at least one selected from the group consisting of a phenyl group and a diisopropylphenyl group. 3. A total amount of a diisocyanate component comprising 5 to 95 equivalent parts of 2,4-tolylene diisocyanate and 95 to 5 equivalent parts of 2,6-tolylene diisocyanate.
With respect to 00 equivalents, 10 to 50 equivalents of aromatic monoisocyanate, in the presence of a carbodiimidization catalyst, in an aprotic organic solvent in an amount of 1 to 5 times the total amount of diisocyanate components, at a temperature of 80 ° C. or higher. The method for producing a carbodiimide copolymer according to claim 1, wherein the polymerization is performed by heating. 4. The method for producing a carbodiimide copolymer according to claim 3, wherein the aprotic organic solvent is at least one selected from the group consisting of toluene, xylene, perkylene and dioxane. 5. The aromatic monoisocyanate is phenyl isocyanate, ortho-tolyl isocyanate, meta-tolyl isocyanate, para-tolyl isocyanate, dimethylphenyl isocyanate, chlorophenyl isocyanate, trifluoromethylphenyl isocyanate, naphthyl isocyanate, isopropylphenyl isocyanate and diisopropyl. The method for producing a carbodiimide copolymer according to claim 3, which is at least one selected from the group consisting of phenyl isocyanate. 6. A group having a structural unit represented by the following formula (1) (Chemical formula 2) in an amount of 5 to 95 equivalent parts and a group having a structural unit represented by a following formula (2) (Chemical formula 2) in an amount of 5 to 5 equivalent units. A carbodiimide-based varnish containing the carbodiimide copolymer according to claim 1, wherein the polymer has a molecular terminal blocked with an aromatic group and a weight average molecular weight of 10,000 or less. [Chemical 2]