JPH10158394A - Production of polycarbodiimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to directly and stably produce the subject polymer having a high mol.wt. and excellent in solution stability without isolating a diisocyanate compound by polymerizing a specific bisurethane compound monomer. SOLUTION: This method for producing a polycarbodiimide having repeating constituting units of formula III [(n) is 8-40] comprises polymerizing (D) a compound of formula I (R1 , R2 are each an alkyl, an aryl) [e.g. a reaction product obtained by reacting a corresponding diamine with a compound of formula II (X is a halogen] in the presence of (A) A carbodiimide-forming catalyst such as 1-phenyl-2-phospholene-1-oxide, (B) a basic compound and (C) an organic silicon halide compound such as trimetlylchlorosilane. Thus, a polycarbodiimide having a number-average mol.wt. of 2000-100000, excellent in storage stability and high in reliability in the form of coating films can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing polycarbodiimide. More specifically, the present invention relates to a method for producing a polycarbodiimide directly from a bisurethane compound as a monomer. The present invention also relates to a method for producing a polycarbodiimide directly from a diamine as a raw material without separating a bisurethane compound as an intermediate. In the production method of the present invention, polycarbodiimide having a high molecular weight and excellent solution stability can be stably obtained.

Conventionally, in order to produce polycarbodiimide, carbodiimidation of an organic diisocyanate is carried out in the presence of a carbodiimidation catalyst. Such a polycarbodiimide has heat resistance in that it does not generate a decomposed monomer or a volatile gas even when exposed to a high temperature of 400 ° C. or more, but loses its self-holding property and becomes brittle when heat-treated at a temperature of 200 ° C. or more. I do not endure. Also high temperature,
Low moisture resistance under high pressure. Therefore, research on polycarbodiimides having excellent characteristics capable of solving such problems has been advanced.

[0003] Diisocyanate, which is a raw material of such polycarbodiimide, is prepared by (i) a method of reacting phosgene, diphenyl carbonate, or carbonyldiimidazole with a corresponding diamine, or (ii) a Curtius rearrangement from a dicarboxylic acid. And the like. Also, (iii) a method of isocyanating the urethane using the thermal decomposition of the corresponding urethane (G. Greber, et.al.,
Angew. Int. Ed., Vol. 7. No.12.941 (1968) and VLKVa
lli, et.al., J. Org. Chem., Vol. 60.257 (1995)).

[0004]

However, the diisocyanate has problems such as being easily hydrolyzed with an active compound, difficult to purify, and having to be handled and stored under dry conditions. Also, due to such isocyanate properties, a high molecular weight polymer cannot be obtained when diisocyanate that is not sufficiently purified is used or under conditions that are susceptible to humidity.

The inventors of the present invention have conducted intensive studies on the selection of a stable monomer capable of obtaining a sufficiently high molecular weight polycarbodiimide and on the polymerization method. As a result, the polymerization was carried out using bisurethane as a monomer, and the diisocyanate was isolated. Without doing this, they found that polycarbodiimides could be obtained directly from them, and completed the present invention. That is, the present invention provides the following general formula (I) R ₂ O—CO—HN—R ₁ —NH—CO—OR ₂ (I) in the presence of a carbodiimidation catalyst, a basic compound, and an organic silicon halide compound. Wherein R ₁ and R _{2 each} represent an alkyl group or an aryl group), wherein a bisurethane compound represented by the following general formula (II) is reacted:

Embedded image (Wherein, n is an integer of 8 to 40, and R ₁ is the same as described above). A method for producing a polycarbodiimide having a structural unit represented by the formula:

Further studies on the production of polycarbodiimide revealed that the production of polycarbodiimide was started at a surprisingly high yield by directly producing polycarbodiimide without isolating bisurethane as an intermediate from diamine as a raw material. It turned out that things were obtained. That is, the present invention reacts a diamine with a halogenated formate to produce the bisurethane as an intermediate, without separating the reaction product, in the presence of a carbodiimidation catalyst, a basic compound and an organic silicon halide compound. To provide a method for producing the polycarbodiimide.

In the case where the reaction is carried out with another catalyst such as chlorocatechol borane, which is conventionally used for isocyanation of urethane, in place of the organic silicon halide compound used in the present invention, carbodiimide cannot be obtained from urethane. Was. As described above, the method for obtaining isocyanate from urethane is described in Angew.Int.Ed., 7 ,
No. 941 (1968), which mentions only monoisocyanates, but does not describe diisocyanates or perform isocyanate production in the presence of a carbodiimidization catalyst.

[0008]

DETAILED DISCLOSURE OF THE INVENTION

(Production of bisurethane from diamine) As the raw material diamine used in the present invention, any diamine may be used, and specific examples thereof include the following.

As the aliphatic diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine,
Decamethylenediamine, undecamethylenediamine, dodecamethylenediamine, doridecamethylenediamine, tetradecamethylenediamine, pentadecamethylenediamine, hexadecamethylenediamine, 2-methylbutane-
1,4-diamine, 2,5-dimethylhexane-1,6-diamine, 2,2,4-trimethylpentane-1,5-diamine, 2,2,4- or 2,4,4-trimethylhexanediamine , Butenediamine, 1,3-butadiene-1,4-diamine, 2-butynylene-1,4-diamine, propane hexafluoro-1,3-diamine, butane octafluoro-1,4-diamine, 16 Octane fluoride-1,8-diamine, methyl ether-ω, ω′-diamine, dipropyl ether-ω,
ω′-diamine, ethylene glycol diethyl ether-1,1′-diamine, 3-methoxyhexamethylene-diamine, 3-butoxyhexamethylene-diamine, propylene glycol dipropyl ether-ω, ω′-diamine, dipropylene glycol diamine Propyl ether
ω, ω'-diamine, carboxyethane-1,2-diamine, carboxypropane-1,3-diamine, carboxybutane-1,4-diamine, di (2-aminocarboxyethyl) ether, 2,2-di ( 4-aminocarboxyphenyl) propane, 1,11-diamino-6-acetoxyundecane, 1,11-diaminoundecane-6-one, bis (2-aminoethyl) carbonate,

Bis (4-aminophenyl) carbonate, lysine diamine, diethyl fumarate-ω, ω'-diamine, diethyl succinate-ω, ω'-diamine, diethyl adipate-ω, ω'-diamine, dimethyl sulfone Diamine, thiodiethyldiamine, thiodipropyldiamine, thiodihexyldiamine, 3,3-dinitropentane-1,5-diamine, 3-nitraza-1,5-pentanediamine, 3,6-dinitraza-1,8-octane Diamine, 2-nitraza-1,4-butanediamine, 3,10-dinitraza-1,12-dodecanediamine, 3,7-dinitraza-1,9-nonanediamine, 3,6,9-trinitraza-1,
Examples include, but are not limited to, 11-undecanediamine, 2,5-dinitraza-1,6-hexanediamine, and the like.

As the alicyclic diamine, cyclopropane-1,2-diamine, cyclopropane-1,2-bis (carbonylamine), cyclobutane-1,2-bis (methylamine), cyclohexane-1,2-diamine Diamine, cyclohexane-1,3-diamine, cyclohexane-1,4-diamine, 1-methylcyclohexane-2,4-diamine, 1-ethylcyclohexane-2,4-diamine, 4,5-dimethylcyclohexane-1,3 -Diamine, 1,2-dimethylcyclohexane-ω, ω′-diamine, 1,4-dimethylcyclohexane-ω, ω′-diamine, isophoronediamine, 1,3,5-trimethyl-2-propylcyclohexane-1ω, 2ω Diamine, dicyclohexylmethane-4,
4'-diamine, dicyclohexylmethylmethane-4,
4'-diamine, dicyclohexyldimethylmethane-4,
4'-diamine, 2,2'-dimethyldicyclohexylmethane-4,4'-diamine, 3,3'-dimethyldicyclohexylmethane-4,4'-diamine, 3,3 ', 5,5'-tetramethyldicyclohexyl Methane-4,4'-diamine, dimer acid diamine, 2,5-aminomethyltetrahydrofuran, 2,2-aminomethyltetrahydrofuran-5,5'-ether, 2,2,4,4-tetramethyl-1,3
-Cyclobutanediamine, 2,2,4,4-tetraethyl-
1,3-cyclobutanediamine, 2,2-dibutyl-2,4-
Diethyl-1,3-cyclobutanediamine, 2,4-diethyl-2,4-dimethyl-1,3-cyclobutanediamine,
2,4-dimethyl-2,4-dipropyl-1,3-cyclobutanediamine, 2,4-diethyl-2,4-dioctyl-1,3
-Cyclobutanediamine, 2,4-didecyl-1,3-cyclobutanediamine, 2- (γ-aminopropyl) cyclohexylamine, 5-dimethyl-1,3-cyclohexylenediamine and the like. In addition, diamines having the following structural formulas are exemplified, but not limited thereto.

[0012]

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As the aliphatic diamine having an aromatic ring, m- and -p-xylene-7,8-diamine, 1,4
-Bis (2-ethylamine) benzene, 1,3- and 1,4
-Bis (isopropylamine) benzene, diaminodiphenylmethane, 1,3-diphenylpropane-1,3-diamine, 1,4- and 1,5-bis (methylamine) naphthalene, bis [4- (methylamine) phenyl] Ether, 4,4 '
-(3-propylamine) biphenyl, 9,10-bis (methylamine) anthracene, bis (2-ethylamine) tere and isophthalic acid, bis (2-ethylamine) -p-phenylenediacetate, etc. However, the present invention is not limited to this.

The aliphatic / aromatic mixed diamine includes toluene-4,7-diamine and ethylbenzene-diamine.
4,7- and 4,8-diamine, propylbenzene-3,9
-And 4,9-diamine, butylbenzene-3,9- and 4,9-diamine, tetrahydronaphthalene-1,5-diamine, hexahydrobenzidine-4,4'-diamine, but are not limited thereto. It is not something to be done.

Among the aromatic diamines, benzene derivatives include 1,3- and 1,4-phenylenediamine, toluene-2,4- and 2,6- and 2,5- and
3,5-diamine, ethylbenzene-2,4-diamine, isopropylbenzene-2,4-diamine, m-xylene-
2,4- and 4,6-diamine, p-xylene-2,5-diamine, diethylbenzenediamine, diisopropylbenzenediamine, 3,5-diethyltoluene-2,4-diamine, 1,5-diethyl-3-methyl Benzene-2,4-diamine, 1,3,5-triethylbenzene-2,4-diamine, 1,3,5-triisopropylbenzene-2,4-diamine, 2,6-dimethylbenzene-1,4- Diamine, 2,6
-Diethylbenzene-1,4-diamine, 2,4-diaminophenol and the like, but are not limited thereto.

Among the aromatic diamines, those containing halogen include 1-trifluoromethylbenzene-3,
4-diamine, 1-chlorobenzene-2,4-diamine,
1,3-dichlorobenzene-2,4-diamine, 1,5-dichlorobenzene-2,4-diamine, 5-bromotoluene-
2,4-diamine, 1-trifluoromethylbenzene-2,4
Diamine, 2,5-dichlorobenzene-1,4-diamine, 2-trifluoromethylbenzene-1,4-diamine, 6
-Bromo-2-methylbenzene-1,4-diamine, and the like, but are not limited thereto.

Among the aromatic diamines, those containing a nitro group include 1-nitrobenzene-2,4-diamine and 2-nitrobenzene-1,4-diamine, but are not limited to these. is not.

Among the aromatic diamines, those containing an alkoxy group include 1-methoxybenzene-2,4-
Diamine, 1-ethoxybenzene-2,4-diamine, 1,
5-dimethoxybenzene-2,4-diamine, 1-propoxybenzene-2,4-diamine, 1-isobutoxybenzene-2,4-diamine, 2-methoxybenzene-1,4-diamine, 2,5-dimethoxy Benzene-1,4-diamine,
Examples thereof include 2,5-diethoxybenzene-1,4-diamine and 2-phenoxybenzene-1,5-diamine.
It is not limited to these.

Among aromatic diamines, naphthalene derivatives include 1,4-naphthalenediamine, 1,5-naphthalenediamine, 1-methylnaphthalene-1,5-diamine, 2,6-naphthalenediamine, Examples include, but are not limited to, 7-naphthalenediamine, 1,1′-dinaphthyl-2,2′-diamine, and the like.

Among aromatic diamines, biphenyl derivatives include biphenyl-2,4'-diamine, biphenyl-4,4'-diamine, 2,2'- and 3,3'-dimethylbiphenyl-4, 4'-diamine, 2,2'-bis (trifluoromethyl) biphenyl-4,4'-diamine, 2,2'- and 3,3'-dimethoxybiphenyl-
4,4'-diamine, 2-nitrobiphenyl-4,4'-diamine, 2,2'- and 3,3'-dihydroxybiphenyl-4,4'-diamine, 3,3'-dichlorobiphenyl-
4,4′-diamine, 2,2 ′, 5,5′-tetrachlorobiphenyl-4,4′-diamine, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diamino-3 , 3'-dimethylbiphenyl-2,2'-disulfonic acid, and the like, but is not limited thereto.

Of the aromatic diamines, di- and triphenylalkane derivatives include diphenylmethane-4,4'-diamine, diphenylmethane-2,2'-diamine, diphenylmethane-2,4'-diamine, 3 '
-Dichlorodiphenylmethane-4,4'-diamine, 3,5
Dimethyldiphenylmethane-4,4'-diamine, 2,
2′-dimethyldiphenylmethane-4,4′-diamine,
3,3'-dimethyldiphenylmethane-4,4'-diamine, 3-methoxydiphenylmethane-4,4'-diamine, 2,4,6-trimethyldiphenylmethane-3,4'-
Diamine, 2,2 ', 5,5'-tetramethyldiphenylmethane-4,4'-diamine, 3,3'-dimethoxydiphenylmethane-4,4'-diamine, 4,4'-dimethoxydiphenylmethane-3,3' Diamine, 4,4′-diethoxydiphenylmethane-3,3′-diamine, 2,2′-dimethyl-5,5′-dimethoxydiphenylmethane-4,4′-diamine, 3,3 ′, 5,5 ′ -Tetraisopropyldiphenylmethane-4,4'-diamine, bis (4-phenylamine) dimethylmethane, bis (3-chlorophenyl-4-amine) dimethylmethane, bis (4-phenylamine) ditrifluoromethylmethane, 2,2 -Bis (3-amino-4-methylphenyl) hexafluoropropane, bis (4-phenylamine) cyclohexylmethane, bis (4-phenylamine) -2-nitrophenylmethane, bis (4-phenylamine) -4- Toro, bis (2,5-dimethylphenyl-4-amine) phenyl methane, bibenzyl -
4,4′-diamine, bibenzyl-2,4′-diamine, bis (4-phenylamine) ethylene, bis (4-phenylamine) difluoroethylene, 9,9-bis (4-aminophenyl) fluorene and the like. Can be In addition, compounds represented by the following structural formulas are also exemplified, but not limited thereto.

[0022]

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Among the aromatic diamines, those having a polybenzene nucleus include 2,7-fluorenediamine,
Examples include, but are not limited to, 2,6-anthraquinone diamine, 3,8-pyrene diamine, 2,8-chrysene diamine, and the like.

Other aromatic diamines include diphenyl ether-2,4'-diamine, diphenyl ether-4,4'-diamine, ethylene glycol diphenyl ether-4,4'-diamine, 1,3-propylene glycol diphenyl ether-4, 4'-diamine, diethylene glycol diphenyl ether-4,4'-diamine, azodiphenyl-4,4'-diamine, 3-methylazodiphenyl-4,4'-diamine, 4-phenylamineazo-
4'-naphthylamine, diphenyl sulfide-2,4 '
-Diamine, diphenylsulfide-4,4'-diamine, 2,2'-dimethylphenyldisulfide-5,5'-
Diamine, 3,3'-dimethyldiphenyl disulfide-
6,6′-diamine, 4,4′-dimethyldiphenyldisulfide-5,5′-diamine, 4,4′-dimethyldiphenyldisulfide-3,3′-diamine, 3,3′-dimethoxydiphenyldisulfide-4, 4′-diamine, diphenylsulfone-4,4′-diamine, diphenylsulfone-3,3′-diamine, 4,4′-dichlorodiphenylsulfone-3,3′-diamine, 4,4′-dimethyldiphenylsulfone 3,3′-diamine, 4,4′-dimethoxydiphenylsulfone-3,3′-diamine, 4,4′-di-tert
-Butyldiphenylsulfone-3,3'-diamine, 4-
Methyldiphenylsulfone-2,4'-diamine and the like. In addition, compounds represented by the following structural formulas are also exemplified, but not limited thereto.

[0025]

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[0026]

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[0027]

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Examples of the heterocyclic diamine include 2,5-di (methylamine) furan, 2,7-dibenzofurandiamine, 3,6-carbazolediamine, 9-ethylcarbazole-3,6-diamine, 8-Dichlorocarbazole-3,6-diamine and the like. In addition, compounds represented by the following structural formulas are also exemplified, but not limited thereto.

[0029]

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Examples of the silicon diamine include dimethyl silicon diamine, di-n-butyl silicon diamine, diphenyl silicon diamine, diethoxy silicon diamine, and diphenoxy silicon diamine. In addition, compounds represented by the following structural formulas are also exemplified, but not limited thereto.

[0031]

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Examples of the phosphorus-containing diamine include phenyl phosphorus diamine, methoxy phosphorus diamine, ethoxy phosphorus diamine, methyl phosphorus oxide diamine, monochloromethyl phosphorus oxide diamine, ethyl phosphorus oxide diamine, isopropyl phosphorus oxide diamine, benzyl phosphorus oxide diamine, and phenyl phosphorus diamine. Examples include, but are not limited to, phosphorus oxide diamine, butoxyline oxide diamine, and phenoxyline oxide diamine.

(Production of Bis-urethane) In the first step of the reaction, bisurethane is obtained by reacting the corresponding diamine with a halogenated formate. As the halogenated formate, those represented by the general formula XCO ₂ R ₂ (where X is halogen, R ₂ is alkyl, aryl or alkoxyl) are preferably used. Specific examples of such halogenated formates include methyl chloroformate, ethyl chloroformate, phenyl chloroformate, p
-Nitrophenyl chloroformate and the like.
Of these, phenyl chloroformate or p-nitrophenyl chloroformate is more preferable in order to obtain a sufficiently activated urethane as a raw material for polycarbodiimide.

The amount of the halogenated formate used is 0.5 to 8.0 times, preferably 1.0 to 5.0 times the number of moles of the diamine. If the amount used is less than this, the reaction does not easily proceed. On the other hand, if the amount used is larger than this, a side reaction may occur, which is not preferable.

The reaction solvent used in the production of bisurethane is not particularly limited as long as it dissolves or suspends the diamine. Examples thereof include ether compounds such as THF, diethyl ether and dioxane, and ketone compounds such as acetone and methyl ethyl ketone. And ester compounds such as ethyl acetate, aromatic hydrocarbon compounds such as toluene, xylene and benzene, and halogenated hydrocarbon compounds such as chloroform and methylene chloride. These solvents may be used alone or as a mixture of two or more. Further, a part or all of the solvent may be replaced during the reaction to change the reaction temperature.

The reaction temperature is from -40 to 110 ° C, preferably from -20 to 90 ° C, most preferably from 0 to 80 ° C. If the reaction temperature is lower than −40 ° C., the reaction hardly proceeds, while 11
At a high temperature exceeding 0 ° C., side reactions such as condensation may occur.

As a base for trapping hydrogen chloride generated at the time of producing bisurethane, any base can be used as long as it dissolves in the used solvent and does not inhibit the reaction. Examples thereof include triethylamine, pyridine and sodium hydroxide. . The amount of the base used is 0.1 mole of the number of moles of the diamine used.
10 to 10 times, preferably 0.5 to 8.0 times, optimally 1.0.
It is up to 5.0 times. When the amount of the base used is less than 0.1 times, the reaction hardly proceeds. On the other hand, when the amount exceeds 10 times, undesirable side reactions may occur.

The bisurethane monomer thus obtained is represented by the above general formula: R ₂ O—CO—HN—R ₁ —NH—CO—OR ₂ (I).

The obtained bisurethane can be purified by a conventionally known method such as recrystallization, column, or distillation, and can be subjected to a polycarbodiimidization reaction. However, it is preferable from the viewpoint of reaction operation and yield that the reaction product obtained in the above reaction is used as it is in the next polycarbodiimidization without isolation.

(Production of polycarbodiimide) In order to produce polycarbodiimide from the above-mentioned bisurethane, the above-mentioned isolated bisurethane or bisurethane is used in the presence of a carbodiimidation catalyst, a basic compound and an organic silicon halide compound. The reaction is carried out using the reaction product thus obtained to produce polycarbodiimide.

(A) Organic silicon halide compound The organic silicon halide compound used in the reaction is represented by the general formula: RnSiX _4-n . Where X is Cl, Br,
A halogen atom such as F or I, and R is a lower alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, or a propyl group;
An aryl group such as a phenyl group and a tolyl group or an alkoxy group such as a methoxy group and a phenoxy group, which may be the same or different.

Of these, compounds in which any of R is an aryl group are difficult to obtain and to remove unreacted compounds, and are not practical. Accordingly, chlorosilanes such as trimethylchlorosilane, triethylchlorosilane, trimethoxychlorosilane, and tetrachlorosilane are particularly suitable, but trimethylchlorosilane is most suitable in terms of ease of handling and price.

The amount of such an organosilicon compound used is
It is 0.1 to 10 times, preferably 0.5 to 8.0 times, most preferably 1.0 to 5.0 times the molar amount of bisurethane. If the amount used is less than this, unreacted raw materials may remain. On the other hand, if the amount used is larger than this, it is difficult to remove it after the reaction is completed, or a side reaction is caused, which is not preferable.

(B) Basic Compound As the basic compound, an organic base or an inorganic base can be used, but an organic base is preferable from the viewpoint of solubility in a solvent. Furthermore, tertiary amines such as triethylamine and pyridine are suitable because they do not inhibit the reaction among organic bases. Primary amines and secondary amines are not preferred because they have active hydrogen and may react with isocyanates which may be present as reaction intermediates. The amount of the basic compound used is 0.1 mole of the number of moles of bisurethane used.
10 to 10 times, preferably 0.5 to 8.0 times, optimally 1.0.
Up to 5.0 times is better. If the ratio is less than 0.1, the reaction hardly proceeds, and if the ratio is 10 or more, undesirable side reactions may occur.

(C) Polymerization catalyst As the polymerization catalyst, any conventionally known carbodiimidization catalyst can be used. For example, 1-phenyl-2
-Phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1
-Oxide, 3-methyl-1-phenylphospholene-1
-Oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide or a phospholene oxide such as a 3-phospholene isomer thereof can be used. The amount of these materials is generally 0.0 urethane.
It is from 5 to 50 mol%, preferably from 0.1 to 40 mol%, most preferably from 0.5 to 30 mol%. If the amount of the polymerization catalyst used is less than this, it may be deactivated during the reaction and the polymerization may be stopped. On the other hand, if the amount of the catalyst is larger than the above range, it may be difficult to control the reaction.

(D) Polymerization Reaction In the reaction, the polymerization catalyst may be added from the beginning of the reaction, or may be added after the isocyanation reaction between bisurethane, an organosilicon compound, and a basic compound is advanced. . That is, the production method of the present invention involves the conversion of bisurethane to carbodiimidation in the presence of a carbodiimidation catalyst, a basic compound and an organosilicon compound, and the order of addition and the like can be appropriately selected.

The polymerization reaction temperature is generally -50 to 200.
° C, preferably -10 to 150 ° C, more preferably 2 ° C
The temperature is 0 to 120 ° C., but may be appropriately changed depending on the combination of the bisurethane and the organosilicon compound used. If the reaction temperature is lower than this, the reaction may not proceed at all.
Conversely, if the reaction temperature is too high or the reaction time is too long, side reactions may occur or the product may decompose.
It is preferable to gradually raise the temperature from a low temperature while tracing the reaction with R or the like.

The reaction solvent used for the polycarbodiimidization may be any solvent capable of dissolving or suspending urethane. Examples thereof include ether compounds such as tetrahydrofuran, dioxane and diethyl ether, and halogenated carbonized compounds such as dichloromethane, chloroform, dichloroethane and tetrachloroethane. Examples include ketone solvents such as hydrogen, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and aromatic hydrocarbons such as toluene, xylene, and benzene. These solvents may be used alone or as a mixture. In some cases, the reaction temperature can be changed by substituting part or all of the reaction during the reaction.

When polycarbodiimidization is carried out without removing bisurethane as an intermediate, the solvent may be any one capable of dissolving or suspending bisurethane. Examples thereof include ether compounds such as tetrahydrofuran and dioxane, and dichloromethane. Halogenated hydrocarbons such as methyl ethyl ketone and cyclohexanone, and aromatic hydrocarbons such as toluene, xylene and benzene are preferably used.

In the production of bisurethane and polycarbodiimide, the diamine concentration or urethane concentration as a raw material is 1 to 50%, preferably 5 to 4% in the reaction mixture.
0%, optimally 10-30% by weight. If the concentration of these raw materials is too low, the reaction requires a long time, which is not practical. On the other hand, if the concentration is too high, an undesirable side reaction may be caused.

The terminal blocking treatment can be carried out by adding a monoisocyanate, a urethane compound or a monoamine during any of the last, middle, and initial stages of the reaction, or over the entire period. By this treatment, the storage stability of the polycarbodiimide solution can be improved. As the monoisocyanate, phenyl isocyanate, p-nitrophenyl isocyanate, p- or m-tolyl isocyanate, p-formylphenyl isocyanate and the like can be used. Examples of urethane compounds include phenyl urethane, 2-phenoxyphenyl-2- (4-phenoxyphenylurethane) hexafluoropropane, p
-Or m-tolyl urethane can be used. Examples of the monoamine include, but are not limited to, 1-naphthylamine, p- or m-tolylamine, and phenoxyphenylamine. The polycarbodiimide solution obtained in this manner is preferable in that the solution has excellent storage stability.

After completion of the reaction, the polycarbodiimide can be isolated and purified by a conventional method. That is, a method of removing the hydrochloride salt generated by the reaction and excess reaction reagent and taking out polycarbodiimide as a solution, or a method of pouring the reaction mixture into a poor solvent such as a lower hydrocarbon or alcohol to precipitate the polymer as a precipitate. There is.
After being precipitated as a precipitate, it is washed and dried by a predetermined operation, and the polycarbodiimide can be taken out as a solid. Further, it can be redissolved in an organic solvent and treated as a varnish.

The molecular weight of the polycarbodiimide thus obtained is 2,000 to 100,000, preferably 4,000 to 20,000 (n = 8 to 40) as a number average molecular weight. If the molecular weight is too high, storage stability is poor and gelation easily occurs even at room temperature, which is not practically preferable. On the other hand, if the molecular weight is too low, it is not preferable because the film lacks reliability.

[0054]

EXAMPLES Next, the present invention will be described more specifically based on examples. In addition, the characteristic of the obtained polycarbodiimide was measured as follows. Molecular weight: It was measured using HLC8120 (manufactured by Tosoh Corporation), and the molecular weight was determined based on polystyrene standards. Intrinsic viscosity: A sample was prepared as a 5 g / L THF solution and measured at 30 ° C. using an Ostwald viscometer.

Example 1 (Synthesis of bisurethane) 2,2-bis (4-aminophenoxyphenyl) was placed in a 1 L three-necked flask equipped with a dropping funnel.
Hexafluoropropane (BAPF) 20.0 g, THF17
8 g and 9.58 g of triethylamine were charged. The dropping funnel was charged with 14.5 g of phenylchloroformic acid, and the reaction vessel was cooled to 0 ° C. in an ice bath. Phenylchloroformic acid was added dropwise over 15 minutes, and the mixture was stirred for 30 minutes while returning to room temperature. The resulting salt was hydrolyzed with 100 g of water and extracted with chloroform. The organic layer was collected and dried over anhydrous magnesium sulfate. After evaporating the solvent and recrystallizing with toluene,
22.2 g (76% yield) of a white solid was obtained. (Production of polycarbodiimide) A dropping funnel and a condenser with a calcium chloride tube were attached to a 50 mL two-necked flask. 2.00 g (2.64 mmol) of phenylurethane of BAPF synthesized as described above and 0.58 of triethylamine
8 g (5.81 mmol), methylene chloride 26.5 g, carbodiimidation catalyst 0.00450 g (0.0234 mmol, 0.8 g).
(89 mol%) was placed in a flask, and the inside was replaced with argon. 0.633 g of trimethylchlorosilane (5.8 at room temperature)
3 mmol) and stirred for 10 minutes. While replacing methylene chloride with an equal amount of toluene, the reaction temperature was gradually raised from room temperature to 80 ° C. over 2 hours, and the mixture was stirred at 80 ° C. for 4 hours. After confirming the completion of carbodiimidation by IR, m-tolyl isocyanate 0.2
07 g (1.55 mmol) was added, and the mixture was further stirred at 80 ° C. for 1.5 hours. The reaction solution was poured into 160 g of ethanol with stirring, and the precipitate was collected and dried under reduced pressure. The obtained white powdery polymer was soluble in an organic solvent and the yield was 1.0.
g (yield 73%), Mn = 8,410, Mw = 26,100, intrinsic viscosity η
inh was 0.1.

Example 2 1,3-bis (4
Example 1 except that (-aminophenoxy) benzene was used.
When a polycarbodiimide was produced in the same manner as described above, a pale yellow powdery polycarbodiimide (yield: 52%) was obtained. This polymer had Mn = 6,410 and Mw = 21,000.

Comparative Example 1 The reaction of bisurethane of Example 1 was carried out in the same manner as in Example 1 except that trimethylchlorosilane was not added. That is, 2.00 g (2.64 mmol) of the urethane produced in Example 1, 0.588 g (5.81 mmol) of triethylamine and 26.56 g of methylene chloride.
5g, 0.00450 g of carbodiimidization catalyst (0.02
34 mmol, 0.89 mol%) was placed in a flask, and the inside was replaced with argon. The mixture was stirred at room temperature for 10 minutes.
While replacing methylene chloride with an equal amount of toluene, the reaction temperature was gradually raised from room temperature to 80 ° C. over 2 hours,
After stirring at 80 ° C. for 4 hours, neither isocyanation nor carbodiimidization proceeded at all.

[Comparative Example 2] The bisurethane of Example 1 was polymerized in the same manner as in Example 1 except that the carbodiimidization catalyst was not added. That is, 2.00 g (2.64 mmol) of urethane synthesized in Example 1, 0.588 g (5.81 mmol) of triethylamine, and 26.5 g of methylene chloride were placed in a flask, and the inside was replaced with argon. 0.633 g (5.83 mmol) of trimethylchlorosilane was added at room temperature, and the mixture was stirred for 10 minutes. The reaction temperature was gradually increased from room temperature to 80 ° C. over 2 hours while replacing methylene chloride with an equal amount of toluene, and the mixture was stirred at 80 ° C. for 4 hours. Did not.

Comparative Example 3 A cooling tube with a calcium chloride tube was attached to a 50 mL two-necked flask. Example 1
2.00 g (2.64 mmol) of urethane synthesized in
0.588 g (5.81 mmol) of triethylamine, 0.00450 g (0.0234 mm) of a carbodiimidization catalyst.
ol, 0.89 mol%) and 17.3 g of toluene were placed in a flask, and the inside of the flask was replaced with argon. 0.910 g (5.90 mmol) of chlorocatechol borane was added at room temperature, and the mixture was stirred for 50 minutes. The reaction temperature was gradually raised from room temperature to 80 ° C. over 2.5 hours, and the mixture was stirred at 80 ° C. for 4 hours. As a result, isocyanation proceeded but carbodiimidization did not proceed at all.

Example 3 In a 1 L three-necked flask equipped with a dropping funnel, 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane (HF-BAPP) 40.0 was used.
g (77.2 mmol), methylene chloride (530 g) and triethylamine (34.4 g, 339 mmol) were charged. The dropping funnel was charged with 24.2 g (154 mmol) of phenyl chloroformate, and the reaction vessel was cooled to 0 ° C. in an ice bath. Phenyl chloroformate was added dropwise over 15 minutes, and the mixture was stirred overnight while returning to room temperature.

Next, a cooling tube with a calcium chloride tube was attached to the flask. Carbodiimidization catalyst
(3-methyl-1-phenylphospholene-1-oxide)
0.104 g (0.540 mmol, 0.70 mol%) was placed in a flask, and the inside of the flask was replaced with argon. At room temperature, 18.4 g (170 mmol) of trimethylchlorosilane was added, and the mixture was stirred for 10 minutes. The reaction temperature was gradually raised from room temperature to 8 over 2 hours while replacing methylene chloride with an equal amount of toluene.
The temperature was raised to 0 ° C, and the mixture was stirred at 80 ° C for 4 hours. After confirming that the carbodiimidation was completed by IR, m-
Add 20.5 g (154 mmol) of tolyl isocyanate,
Stirred at 80 ° C. for a further 1.5 hours.

The reaction solution was poured into 3160 g of methanol with stirring, and the precipitate was collected and dried under reduced pressure. The obtained white powdery polymer was soluble in organic solvents and the yield was 3
6.0 g (yield 90%), Mn = 8,400, Mw = 26,000 and intrinsic viscosity ηinh were 0.1.

Example 4 1,3-bis as diamine
When a polymer was synthesized in the same manner as in Example 3 except that (4-aminophenoxy) benzene was used, a pale yellow powdery polymer was obtained with a yield of 86%. This polymer is M
n = 6,400 and Mw = 21,000.

Example 5 A polymer was synthesized in the same manner as in Example 3 except that toluenediamine (a mixture of 2,4- and 2,6-isomers) was used as a diamine. Obtained in 78% yield. This polymer had Mn = 1,900 and Mw = 3,300.

Comparative Example 4 (Synthesis of Bis-urethane) 40.0 g of 2,2-bis (4-aminophenoxyphenyl) hexafluoropropane (HF-BAPP) was placed in a 1 L three-necked flask equipped with a dropping funnel.
(77.2 mmol), THF 356 g, triethylamine 1
9.2 g (190 mmol) were charged. 29.7 g (190 mmol) of phenyl chloroformate was placed in the dropping funnel, and the reaction vessel was cooled to 0 ° C. in an ice bath. Phenyl chloroformate was added dropwise over 15 minutes, and the mixture was stirred overnight while returning to room temperature. Precipitated salts were removed by washing with water, and further extracted three times with 300 g of chloroform. The extract was collected and dried over magnesium sulfate. Evaporation of the solvent gave a white solid.
By recrystallizing with 340 g of toluene, BAPF-
49.2 g (83% yield) of urethane was obtained.

(Synthesis of Isocyanate) In a 1 L three-necked flask equipped with a dropping funnel, a reflux tube and a calcium chloride tube, 49.2 g (64.g) of the BAPF-urethane synthesized above was placed.
9 mmol), 554 g of methylene chloride, 1 of triethylamine
9.7 g (195 mmol) was added, and 21.1 g (195 mmol) of trimethylchlorosilane was added dropwise at room temperature over 10 minutes. After confirming that the addition of trimethylchlorosilane proceeded to produce triethylamine hydrochloride, toluene 36
2 g was added, the temperature was raised from room temperature to 100 ° C. over 4 hours, and methylene chloride was distilled off. Further temperature up to 120 ° C
And stirred for 2 hours. After confirming by IR that the absorption of carbonyl disappeared and the absorption of isocyanate appeared, the precipitated salt was removed by filtration. Solution is 1/3
And concentrated to a flash column (silica gel 39).
4g, developing solvent: methylene chloride)
50 mL of the clear fraction was collected. Evaporation of the solvent gave 18.0 g (33.1 mmol, 49% yield, 41% overall yield) of BAPF-isocyanate as a white solid.

(Synthesis of Polycarbodiimide) 18.0 g of the BAPF-isocyanate synthesized above was placed in a 200 mL eggplant flask equipped with a reflux tube and a calcium chloride tube.
(33.1 mmol), THF 72 g, carbodiimidization catalyst
(3-methyl-1-phenylphospholene-1-oxide)
0.0445 g (0.232 mmol, 0.70 mol%) was charged. The mixture was stirred at 60 ° C for 6.5 hours, and after confirming that the carbodiimidization was completed by IR, 8.80 g (66.2 mmol) of m-tolyl isocyanate was added, and the mixture was further stirred at 60 ° C for 1.5 hours. . The reaction solution was poured into 1000 mL of methanol with stirring, and the precipitate was collected and dried under reduced pressure. The obtained white powdery polymer was soluble in an organic solvent and was obtained in a yield of 8.89 g (yield 51%, overall yield 21%).
600, Mw = 3,800.

[Comparative Example 5] 3,3'-bis as diamine
Synthesis was performed in the same manner as in Comparative Example 4 except that (4-aminophenoxy) benzene (TPE-R) was used. The yield of TPE-R-urethane was 65%, the yield of TPE-R isocyanate was 66% (43% overall yield), and the yield of TPE-R-carbodiimide was 42% (18% overall yield). Was. The polymer had Mn = 4,200 and Mw = 15,000.

[0069]

According to the method for producing polycarbodiimide of the present invention, the raw materials are stable, easy to handle, and can be stored for a long time. In addition, a sufficiently high molecular weight polycarbodiimide can be obtained. In particular, when polycarbodiimidization is carried out from a diamine in one step, the overall yield is remarkably improved as compared with the conventional method, and the industrial value is high.

Claims (5)

[Claims] [Claim 1] In the presence of a carbodiimidation catalyst, a basic compound and an organic silicon halide compound, a compound represented by the following general formula (I): R ₂ O—CO—HN—R ₁ —NH—CO—OR ₂ (I) Wherein R ₁ and R ₂ represent an alkyl group or an aryl group), wherein a bisurethane compound represented by the following general formula (II) is reacted: (Wherein, n is an integer of 8 to 40, and R ₁ is the same as described above). 2. The reaction of a diamine with a halogenated formate to form a bisurethane compound, and the reaction is carried out in the presence of a carbodiimidation catalyst, a basic compound and an organic silicon halide compound without separating the reaction product. A method for producing the polycarbodiimide according to claim 1. 3. The poly according to claim 2, wherein the halogenated formate is represented by the following general formula (III): XCO ₂ R ₂ (where X is a halogen, R ₂ is an alkyl group, an aryl group or an alkoxyl group). A method for producing carbodiimide. 4. An organic silicon halide compound represented by the following general formula (IV): RnSiX _4-n (IV) wherein X is a halogen atom, R is each independently an alkyl group, an aryl group or an alkoxy group, and n is 0. The method of producing a polycarbodiimide according to claim 1 or 2, which means an integer of from 1 to 3. 5. The method for producing a polycarbodiimide according to claim 1, wherein a tertiary amine is used as the basic compound.