Method for producing isocyanate composition and isocyanate composition

Abstract

To provide a method for producing an isocyanate composition which can obtain an organic isocyanate having a carbodiimide group and / or a urethoneimine group having a lower color number and excellent storage stability, suppresses damage to facilities and has excellent workability.SOLUTION: There is provided a method for producing an isocyanate compound which comprises: adding a phosphorene-based catalyst (B) to an organic isocyanate (A) to carbodiimidate and / or uretoniminate an isocyanate group of the organic isocyanate (A); and adding a terminator (C) to stop the carbodiimidation and / or uretonimination, wherein the terminator (C) contains a sulfonic acid anhydride and the amount added of the sulfonic acid anhydride is 10 or more times moles and 40 or less times moles relative to the amount added of the phosphorene-based catalyst (B).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for producing an isocyanate composition and to an isocyanate composition. [Background technology]

[0002] Organic isocyanates containing carbodiimide groups and / or uretonimine groups are known, which are obtained by reacting organic isocyanates with catalysts such as alkyl phosphate catalysts and phospholene catalysts. Organic isocyanates containing carbodiimide groups and / or uretonimine groups are used as raw materials for paints, thermosetting elastomer foams, etc.

[0003] Patent Document 1 discloses the carbodiimidization of an organic isocyanate with a trialkyl phosphate or the like. In addition, in the carbodiimidization of organic isocyanates using a phospholene catalyst, the activity of the phospholene catalyst is high and the reaction proceeds even at low temperatures, so the carbodiimidization is stopped midway using a terminator. Patent Document 2 discloses that trifluoromethanesulfonic acid is used as a terminator in the carbodiimidization of organic isocyanates using a phospholene catalyst. Patent Document 2 also discloses that such organic isocyanates having a carbodiimide group have excellent storage stability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 52-2908 [Patent Document 2] JP 2000-109539 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the isocyanate composition according to Patent Document 1 has a high degree of coloration of the resulting isocyanate composition containing a carbodiimide group and / or a uretonimine group. Meanwhile, since trifluoromethanesulfonic acid is a deleterious substance and a super acid, the isocyanate composition according to Patent Document 2 has a risk of corroding equipment during its production and is poor in workability. Therefore, one embodiment of the present disclosure is directed to providing a method for producing an isocyanate composition that can provide an organic isocyanate having a carbodiimide group and / or a uretonimine group with a low color number and excellent storage stability, while suppressing damage to equipment and providing excellent workability. Another embodiment of the present disclosure is directed to providing an isocyanate composition that can be obtained by a process that suppresses damage to equipment and provides excellent workability, while also having a low color number and excellent storage stability. [Means for solving the problem]

[0006] According to one embodiment of the present disclosure, adding a phosphorene-based catalyst (B) to an organic isocyanate (A) to convert an isocyanate group of the organic isocyanate (A) into a carbodiimid group and / or a uretonimine group; and then adding a terminating agent (C) to terminate the carbodiimidization and / or uretoniminization, the terminator (C) comprises a sulfonic acid anhydride; The method for producing an isocyanate composition is provided in which the amount of the sulfonic acid anhydride added is 10 to 40 times by mol relative to the amount of the phosphorene-based catalyst (B) added.

[0007] According to another embodiment of the present disclosure, The present invention relates to a method for producing a polymerizable composition comprising the reaction product of an organic isocyanate (A), a phosphorene-based catalyst (B), and a terminator (C), The terminator (C) is an isocyanate composition containing a sulfonic acid anhydride, The reaction product is A modified isocyanate in which a part of the organic isocyanate (A) is converted into a carbodiimide and / or a uretonimine; and an unmodified isocyanate which is a remaining portion of the organic isocyanate (A), An isocyanate composition, characterized in that the amount of change over one month of the unmodified isocyanate measured according to the following measurement method is -2.0% or more and 0% or less: [Measurement method] (1) measuring the molecular weight distribution of a sample of the isocyanate composition by gel permeation chromatography, and calculating the peak area % near the peak top molecular weight of the unmodified isocyanate to obtain the peak area % before storage; (2) storing a sample of the isocyanate composition in a 45°C environment for one month, measuring the molecular weight distribution of the sample after storage by gel permeation chromatography, and calculating the peak area% near the peak top molecular weight of the unmodified isocyanate to obtain the peak area% after storage; (3) The one-month change amount is calculated using the following formula. (Change over one month) = (Peak area after storage%) - (Peak area before storage%) Effect of the Invention

[0008] According to one embodiment of the present disclosure, an organic isocyanate having a carbodiimide group and / or a uretonimine group, which has a low color number and excellent storage stability, can be obtained, and a method for producing an isocyanate composition, which suppresses damage to equipment and has excellent workability, can be provided. According to another embodiment of the present disclosure, an isocyanate composition, which has a low color number and excellent storage stability, can be obtained by a method, which suppresses damage to equipment and has excellent workability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Exemplary embodiments for carrying out the present invention are described in detail below.

[0010] [Method for producing isocyanate composition] One embodiment of the present disclosure comprises: adding a phosphorene-based catalyst (B) to an organic isocyanate (A) to convert an isocyanate group of the organic isocyanate (A) into a carbodiimid group and / or a uretonimine group; and then adding a terminating agent (C) to terminate the carbodiimidization and / or uretoniminization, the terminator (C) comprises a sulfonic acid anhydride; In the method for producing an isocyanate composition, the amount of the sulfonic acid anhydride added is 10 to 40 times by mol relative to the amount of the phosphorene-based catalyst (B) added.

[0011] <Carbodiimide and / or uretonimine formation> The conversion of the isocyanate group of the organic isocyanate (A) into carbodiimid and / or uretonimine is carried out by adding a phosphorene-based catalyst (B) to the organic isocyanate (A) and reacting the organic isocyanate (A). Next, a terminator (C) is added to the organic isocyanate (A) in which some of the isocyanate groups have been converted into carbodiimid and / or uretonimine and the phosphorene-based catalyst (B) to terminate the carbodiimidization and / or uretoniminization.

[0012] The reaction temperature for the carbodiimidization and / or uretoniminization reaction is preferably within a range of 80 to 120° C. When the reaction temperature is within this range, the amount of catalyst can be further reduced, the reaction can be easily controlled, and coloration can be further suppressed.

[0013] After the reaction is terminated by adding the terminator (C), the carbodiimidization reaction may be terminated and the resulting product may be used as an isocyanate composition as is.

[0014] In addition, the method may further include aging after the reaction is terminated by adding a terminator (C). That is, the reaction may be terminated and then aged to produce an isocyanate composition after the uretoniminization reaction. By carrying out the uretoniminization reaction, a polyisocyanate composition having even better storage stability can be obtained. The temperature condition for aging is preferably 30 to 70°C, and more preferably 40 to 60°C.

[0015] <Organic isocyanate (A)> Specific examples of the organic isocyanate (A) include the following: Monoisocyanates Phenyl isocyanate, tolyl isocyanate, chlorophenyl isocyanate, naphthyl isocyanate, and the like. Polyisocyanates Aromatic isocyanates such as toluene diisocyanate, diphenylmethane diisocyanate (hereinafter referred to as MDI), paraphenylene diisocyanate, metaphenylene diisocyanate, naphthalene-1,5-diisocyanate, triphenylmethane-4,4',4''-triisocyanate, and polyphenylene polymethylene polyisocyanate; hexamethylene diisocyanate, 1,10-decane diisocyanate, 1,12 Aliphatic or cycloaliphatic isocyanates such as dodecane diisocyanate, cyclobutane 1,3-diisocyanate, cyclohexane 1,3- and 1,4-diisocyanate, isophorone diisocyanate, 2,4- and 2,6-hexahydrotoluylene diisocyanate, hexahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate. ·Isocyanate-terminated prepolymer Isocyanate-terminated prepolymers obtained by reacting the above isocyanates with glycols, triols, etc. Among these organic isocyanates, MDI is preferred.

[0016] <Phosphorene-based catalyst (B)> As the phosphorene catalyst (B), any of those known as a carbodiimide catalyst for isocyanates can be used. Representative examples include 3-methyl-1-phenyl-3-phospholene-1-oxide, 1-methyl-3-methyl-3-phospholene-1-oxide, 1-ethyl-3-methyl-3-phospholene-1-oxide, 1-butyl-3-methyl-3-phospholene-1-oxide, 1-(N-piperidinyl)-3-methyl-3-phospholene-1-oxide, 1-morpholino-3-methyl-3-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, 1-methyl-3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1-butyl-3-methyl-2-phospholene-1-oxide, 1-phenyl Examples of the phosphorene-1-oxide include 1-phenyl-3-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, 1-methoxy-3-phospholene-1-oxide, 1-butoxy-3-phospholene-1-oxide, 3-methyl-1-ethyl-3-phospholene-1-sulfide, 3-methyl-1-phenyl-3-phospholene-1-sulfide, and mixtures thereof. Among these, 3-methyl-1-phenyl-3-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, 1-phenyl-3-phospholene-1-oxide, 1-phenyl-2-phospholene-1-oxide, and the like are preferred because of their high catalytic activity.

[0017] The conditions for the carbodiimidization and / or uretoniminization reaction depend on the properties of the organic isocyanate (A), but the amount of the phosphorene-based catalyst (B) added is preferably 0.1 ppm or more and 50 ppm or less, and more preferably 0.5 ppm or more and 30 ppm or less, based on the mass of the isocyanate composition.

[0018] <Terminator (C)> The terminator (C) includes a sulfonic acid anhydride, which can terminate the carbodiimidization and / or uretoniminization caused by the reaction of the organic isocyanate (A) with the phosphorene-based catalyst (B). Examples of sulfonic anhydrides include aliphatic alkylsulfonic anhydrides such as methanesulfonic anhydride and ethanesulfonic anhydride, p-toluenesulfonic anhydride, and trifluoromethanesulfonic anhydride. Among these, trifluoromethanesulfonic anhydride is preferred because it has a good effect of terminating the carbodiimide formation and / or uretonimide formation. The terminator (C) may contain a terminator other than sulfonic anhydride. The amount of sulfonic acid anhydride added is 10 to 40 times by mol relative to the amount of phosphorene catalyst (B). If the amount is less than 10 times by mol, the effect of stopping carbodiimide formation and / or uretonimine formation is low. If the amount is more than 40 times by mol, the resulting isocyanate composition becomes highly colored.

[0019] <Other ingredients (D)> In the method for producing an isocyanate composition according to the present embodiment, a light stabilizer, an antioxidant, an ultraviolet absorber, etc. may be added. These may be added at any timing, for example, they may be added to the organic isocyanate (A) in advance, may be added to the organic isocyanate (A) together with the phosphorene catalyst (B), may be added to the organic isocyanate (A) together with the terminator (C), or may be added at a timing different from these.

[0020] Examples of light stabilizers include hindered amines, examples of antioxidants include hindered phenols and phosphites, and examples of ultraviolet absorbing agents include benzotriazoles.

[0021] Hindered amine light stabilizers include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-undecanoxyl-2,2,6,6-tetramethylpiperidin-4-yl)carboxyl, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, and mixtures thereof. Of these, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate and bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate are preferred.

[0022] Hindered phenol and phosphite antioxidants include 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 4,4,4-(1-methylpropanyl-3-ylidene)tris(6-t-butyl-m-cresol), 6,6-di-t-butyl-4,4'-butylidene-di-m-cresol, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, pentaerythritol tetrakis[3-(3,5- di-t-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3,5-tris(3,5-di-t-butyl-4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene, 2,6-di-t-butyl-p-cresol, triphenyl phosphite, trisnonylphenyl phosphite, tricresyl phosphite, triethyl phosphite, tris(2-ethylhexyl)phosphite, tridecyl phosphite, trilauryl phosphite, tris(tridecyl)phosphite, trioleyl phosphite, diphenyl mono(2-ethylhexyl)phosphite, diphenyl monodecyl phosphite, diphenyl mono(tridecyl)phosphite, trilauryl trithiophosphite, tetraphenyl dipropylene glycol diphosphite, tetraphenyl (tetratridecyl) pentaerythritol tetraphosphite, tetra(C12-C15 alkyl )-4,4'-isopropylidenediphenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, bis(decyl)pentaerythritol diphosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, hydrated bisphenol A phosphite polymer, and mixtures thereof.Of these, 2,6-di-t-butyl-p-cresol, triphenyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, and pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] are preferred.

[0023] Examples of the benzotriazole-based ultraviolet absorbers include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-t-amylphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-t-octylphenol], 6-(2-benzotriazole-4-t-octyl-6'-t-butyl-4'-methyl-2,2'-methylenebisphenol), and mixtures thereof.

[0024] [Isocyanate composition] Another embodiment of the present disclosure is The present invention relates to a method for producing a polymerizable composition comprising the reaction product of an organic isocyanate (A), a phosphorene-based catalyst (B), and a terminator (C), The terminator (C) is an isocyanate composition containing a sulfonic acid anhydride, The reaction product is A modified isocyanate in which a part of the organic isocyanate (A) is converted into a carbodiimide and / or a uretonimine; and an unmodified isocyanate which is a remaining portion of the organic isocyanate (A), An isocyanate composition, characterized in that the amount of change over one month of the unmodified isocyanate measured according to the following measurement method is -2.0% or more and 0% or less: [Measurement method] (1) measuring the molecular weight distribution of a sample of the isocyanate composition by gel permeation chromatography, and calculating the peak area % near the peak top molecular weight of the unmodified isocyanate to obtain the peak area % before storage; (2) storing a sample of the isocyanate composition in a 45°C environment for one month, measuring the molecular weight distribution of the sample after storage by gel permeation chromatography, and calculating the peak area% near the peak top molecular weight of the unmodified isocyanate to obtain the peak area% after storage; (3) The one-month change amount is calculated using the following formula. (Change over one month) = (Peak area after storage%) - (Peak area before storage%) The isocyanate composition according to this embodiment will be described below, but the description overlapping with the description of the above-mentioned method for producing the isocyanate composition will be omitted.

[0025] <Reaction products> The reaction product is obtained by reacting an organic isocyanate (A), a phosphorene-based catalyst (B), and a terminator (C). That is, the isocyanate group of the organic isocyanate (A) is converted to carbodiimid and / or uretonimine by the phosphorene-based catalyst (B), and the reaction is terminated by the terminator (C), thereby forming the reaction product.

[0026] Thus, the reaction product is: a modified isocyanate in which a part of the organic isocyanate (A) is carbodiimidized and / or uretonimined; and an unmodified isocyanate which is a remaining portion of the organic isocyanate (A). The organic isocyanate (A) is partially modified to form a modified isocyanate, and the remainder remains unmodified (unmodified isocyanate), and these are present together in the reaction product.

[0027] <Changes over one month> The isocyanate composition preferably has a one-month change in the unmodified isocyanate measured according to the following measurement method of -2.0% or more and 0% or less, more preferably -1.0% or more and 0% or less. If the one-month change is within this range, modification of the unmodified isocyanate is suppressed for a long period of time even in a high-temperature environment, which is preferable.

[0028] [Measurement method] (1) The molecular weight distribution of a sample of an isocyanate composition is measured by gel permeation chromatography, and the peak area % near the peak top molecular weight of the unmodified isocyanate is calculated to obtain the peak area % before storage; (2) storing a sample of the isocyanate composition in a 45°C environment for one month, measuring the molecular weight distribution of the sample after storage by gel permeation chromatography, and calculating the peak area% near the peak top molecular weight of the unmodified isocyanate to obtain the peak area% after storage; (3) The one-month change amount is calculated using the following formula. (Change over one month) = (Peak area after storage%) - (Peak area before storage%) EXAMPLES

[0029] The present invention will be described in more detail below with reference to examples and comparative examples. However, the present invention should not be construed as being limited by these examples. In the following, "%" means "% by mass" unless otherwise specified.

[0030] The following components were used in the examples and comparative examples. [Organic isocyanate (A)] · a1-1; 4,4'-MDI (Millionate MT, manufactured by Tosoh Corporation, isocyanate group content = 33.6%)

[0031] [Phosphorene-based catalyst (B)] b1-1: 3-Methyl-1-phenyl-2-phosphorene-1-oxide (Tokyo Chemical Industry Co., Ltd.) [Phosphate-based catalyst] ·b1-2; Trimethyl phosphate (Tokyo Chemical Industry Co., Ltd.)

[0032] [Terminator (C)] · c1-1: Trifluoromethanesulfonic anhydride (Tokyo Chemical Industry Co., Ltd.) c1-2: Trifluoromethanesulfonic acid trimethylsilyl ester (Tokyo Chemical Industry Co., Ltd.) c1-3: Trifluoromethanesulfonic acid (Tokyo Chemical Industry Co., Ltd.)

[0033] [Examples 1 to 4] (Example 1: Production of polyisocyanate composition (A-1)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and stopped by adding 30ppm of c1-1. Then, the mixture was aged at 60°C for 16 hours to perform uretoniminization, and a polyisocyanate composition was obtained. This polyisocyanate composition is designated as (A-1). The isocyanate group (NCO) content in the polyisocyanate composition (A-1) was 28.8% by mass, and the viscosity at 25°C was 55mPa·s. Its properties are shown in Table 1. In Example 1, no white smoke was generated during production, and workability was excellent.

[0034] (Example 2: Production of polyisocyanate composition (A-2)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and stopped by adding 70ppm of c1-1. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (A-2). The isocyanate group (NCO) content in the polyisocyanate composition (A-2) was 28.7% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In Example 2, no white smoke was generated during production, and workability was good.

[0035] (Example 3: Production of polyisocyanate composition (A-3)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and stopped by adding 100ppm of c1-1. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (A-3). The isocyanate group (NCO) content in the polyisocyanate composition (A-3) was 28.9% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In Example 3, no white smoke was generated during production, and workability was good.

[0036] (Example 4: Production of polyisocyanate composition (A-4)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 85°C while stirring under a nitrogen stream. Next, 4ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 85°C for 7 hours and stopped by adding 60ppm of c1-1. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (A-4). The isocyanate group (NCO) content in the polyisocyanate composition (A-4) was 28.8% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In Example 4, no white smoke was generated during production, and workability was good.

[0037] (Reference Example 1: Production of polyisocyanate composition (B-1)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and terminated by adding 56ppm of c1-2. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (B-1). The isocyanate group (NCO) content in the polyisocyanate composition (B-1) was 28.7% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In addition, in Reference Example 1, white smoke was generated during production.

[0038] (Reference Example 2: Production of polyisocyanate composition (B-2)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and stopped by adding 38ppm of c1-3. Then, the mixture was aged at 60°C for 16 hours to perform uretoniminization, and a polyisocyanate composition was obtained. This polyisocyanate composition is designated as (B-2). The isocyanate group (NCO) content in the polyisocyanate composition (B-2) was 28.7% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In Reference Example 2, the workability was poor because trifluoromethanesulfonic acid was used during the production. In addition, the use of trifluoromethanesulfonic acid raises concerns about damage to the production equipment if the production is carried out over a long period of time.

[0039] (Comparative Example 1: Production of Polyisocyanate Composition (B-3)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and stopped by adding 15ppm of c1-1. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (B-3). The isocyanate group (NCO) content in the polyisocyanate composition (B-3) was 28.7% by mass, and the viscosity at 25°C was 58mPa·s. Its properties are shown in Table 1. In addition, in Comparative Example 1, no white smoke was generated during production, and the workability was good.

[0040] (Comparative Example 2: Production of Polyisocyanate Composition (B-4)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 95°C while stirring under a nitrogen stream. Next, 2ppm of b1-1 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 95°C for 6.5 hours and terminated by adding 140ppm of c1-1. After that, uretoniminization was carried out by aging at 60°C for 16 hours to obtain a polyisocyanate composition. This polyisocyanate composition is designated as (B-4). The isocyanate group (NCO) content in the polyisocyanate composition (B-4) was 28.9% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In addition, in Comparative Example 2, no white smoke was generated during production, and the workability was good.

[0041] (Comparative Example 3: Production of Polyisocyanate Composition (B-5)) 1000g of a1-1 was added to a 2-liter four-neck flask, and the temperature was adjusted to 220°C while stirring under a nitrogen stream. Next, 2500ppm of b1-2 was added while stirring to perform carbodiimidization. The carbodiimidization reaction was carried out at 220°C for 6 hours, and then the reactor was rapidly cooled to 45°C with ice water to stop the reaction. After that, uretoniminization was carried out by aging at 45°C for 48 hours, and a polyisocyanate composition was obtained. This polyisocyanate composition is designated as (B-5). The isocyanate group (NCO) content in the polyisocyanate composition (B-5) was 28.9% by mass, and the viscosity at 25°C was 54mPa·s. Its properties are shown in Table 1. In addition, in Comparative Example 3, no white smoke was generated during production, and the workability was good.

[0042] [Table 1]

[0043] [Storage stability] [Examples 1-4, Reference Examples 1-2, Comparative Examples 1-3] Accelerated aging tests shown in Table 2 were carried out to compare storage stability for Examples 1 to 4, Reference Examples 1 and 2, and Comparative Examples 1 to 3. Each sample was an isocyanate composition sample, which was stored under the following environment, and then subjected to accelerated aging tests (measurement of NCO content, viscosity over time, and MDI monomer content over time). Untreated (not stored in high temperature environment) Store at 45℃ for 2 weeks Store at 45℃ for 1 month

[0044] [Table 2]

[0045] The values ​​shown in Tables 1 and 2 were calculated from the following test results. [NCO content measurement] In the polyisocyanate compositions of Examples 1 to 4, Reference Examples 1 and 2, and Comparative Examples 1 to 3 shown in Tables 1 and 2, the NCO content was measured in accordance with JIS K1603-1:2007. The change (%) in the NCO content over time at 45° C. for one month is preferably −0.30% or more and 0% or less, particularly preferably −0.20% or more and 0% or less.

[0046] [Viscosity measurement] The viscosities of the polyisocyanate compositions shown in Tables 1 and 2 in Examples 1 to 4, Reference Examples 1 to 2, and Comparative Examples 1 to 3 were measured in an atmosphere of 25° C. using a B-type rotational viscometer.

[0047] [MDI monomer content measurement] In the polyisocyanate compositions of Examples 1 to 4, Reference Examples 1 to 2, and Comparative Examples 1 to 3 shown in Tables 1 and 2, the MDI monomer content (peak area %) was determined by GPC (Gel Permeation Chromatography) under the following conditions and method.

[0048] <Measurement conditions> Measuring device: "HLC-8120 (product name)" (manufactured by Tosoh Corporation) Column: Three types of packing materials, TSKgel G3000HXL, TSKgel G2000HXL, and TSKgel G1000HXL (all product names, manufactured by Tosoh Corporation), were connected in series and measurements were performed at a column temperature of 40°C. Detector: RI (refractive index) meter Eluent: tetrahydrofuran (THF) (flow rate: 1 mL / min., 40°C) Calibration curve: A calibration curve was obtained using the following grades of polystyrene (TSK standard POLYSTYRENE; manufactured by Tosoh Corporation). F-2(1.81×10 4 )F-1(1.02×10 4 )A-5000(5.97×10 3 )A-2500(2.63×10 3 )A-500(Mw=6.82×10 2 , 5.78×10 2 , 4.74×10 2 , 3.70×10 2 , 2.66×10 2 ) Toluene (Mw=92) Sample: 0.05 g of sample in 10 mL of tetrahydrofuran

[0049] <Measurement method> First, a calibration curve was obtained from a chart obtained by detecting the refractive index difference using polystyrene as a standard substance. Next, for each sample, the peak area % of the peak near the peak top molecular weight (number average molecular weight) of 230, which indicates the MDI monomer, was calculated from the chart obtained by detecting the refractive index difference based on the same calibration curve. The change in the content (peak area %) of MDI monomer (unmodified isocyanate) over one month at 45° C. is preferably −2.0% or more and 0% or less, more preferably −1.0% or more and 0% or less.

[0050] [Color measurement] In the polyisocyanate compositions of Examples 1 to 4, Reference Examples 1 to 2, and Comparative Examples 1 to 3 shown in Tables 1 and 2, 150 g of the resulting polyisocyanate compositions were placed in a 200 ml sample bottle, and the color number was evaluated by comparing with the color number standard sample. APHA No. was used as the unit. From the viewpoint of the appearance of the molded product, the number of colors is preferably 500 APHA or less.

[0051] According to one embodiment of the present disclosure, an isocyanate composition having a carbodiimide group and / or a uretonimine group can be provided by a production method that suppresses quality deterioration due to further polymerization, suppresses damage to equipment, and ensures excellent workability, thereby providing an isocyanate composition with a low color number and excellent storage stability.

Claims

1. adding a phosphorene-based catalyst (B) to an organic isocyanate (A) to convert an isocyanate group contained in the organic isocyanate (A) into a carbodiimid group and / or a uretonimine group; and then adding a terminating agent (C) to terminate the carbodiimidization and / or uretoniminization, the terminator (C) comprises a sulfonic acid anhydride; The method for producing an isocyanate composition, wherein the amount of the sulfonic acid anhydride added is 10 to 40 times by mol relative to the amount of the phosphorene-based catalyst (B) added.

2. 2. The method for producing an isocyanate composition according to claim 1, wherein the sulfonic anhydride is trifluoromethanesulfonic anhydride.

3. 3. The method for producing an isocyanate composition according to claim 1, wherein the organic isocyanate (A) contains diphenylmethane diisocyanate.

4. The method for producing an isocyanate composition according to any one of claims 1 to 3, characterized in that the amount of the phosphorene-based catalyst (B) added is 0.1 ppm or more and 50 ppm or less based on the mass of the isocyanate composition.

5. An isocyanate composition comprising a reaction product of an organic isocyanate (A), a phosphorene-based catalyst (B), and a terminator (C), the terminator (C) comprises a sulfonic acid anhydride; The reaction product is a modified isocyanate in which a part of the organic isocyanate (A) is converted into a carbodiimide and / or a uretonimine; and an unmodified isocyanate which is a remaining portion of the organic isocyanate (A), An isocyanate composition, characterized in that the amount of change over one month of the unmodified isocyanate measured according to the following measurement method is -2.0% or more and 0% or less: [Measurement method] (1) measuring the molecular weight distribution of a sample of the isocyanate composition by gel permeation chromatography, and calculating the peak area % near the peak top molecular weight of the unmodified isocyanate to obtain the peak area % before storage; (2) storing a sample of the isocyanate composition in a 45° C. environment for one month, measuring the molecular weight distribution of the sample after storage by gel permeation chromatography, and calculating the peak area % near the peak top molecular weight of the unmodified isocyanate to obtain the peak area % after storage; (3) The one-month change amount is calculated using the following formula: (Change over one month) = (Peak area after storage%) - (Peak area before storage%)

6. 6. The isocyanate composition according to claim 5, wherein the sulfonic anhydride is trifluoromethanesulfonic anhydride.

7. 7. The isocyanate composition according to claim 5, wherein the organic isocyanate (A) comprises diphenylmethane diisocyanate.

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