CN118290461A - Isocyanate polymerization catalyst and preparation method thereof, and preparation method of polyisocyanate - Google Patents

Abstract

The invention discloses an isocyanate polymerization catalyst, a preparation method thereof and a preparation method of polyisocyanate, wherein the structural expression of the catalyst is as follows:

Description

Isocyanate polymerization catalyst and preparation method thereof, and preparation method of polyisocyanate

Technical Field

The invention relates to the field of isocyanate polymerization, in particular to an isocyanate polymerization catalyst and a preparation method thereof, and a preparation method of polyisocyanate.

Background

Aliphatic diisocyanate-based polymers have the irreplaceable advantage in polyurethane coatings and adhesives and are widely used. However, the industrial monomeric aliphatic isocyanates are volatile and have great toxicity, so that the application of the monomeric aliphatic isocyanates is relatively large, and the monomeric aliphatic isocyanates are prepared into polyisocyanates for use. Since isocyanurate has excellent rigidity, hydrolysis resistance stability and thermal stability, and is widely used in industrial fields, catalysts for trimerization of isocyanates have been widely studied. Currently, there are many kinds of trimerization catalysts, including complex catalysts (CN 1074312), metal salt compounds (US 4066628), phosphine compounds (US 3702839), nitrogen heterocyclic compounds (US 2013016865), tertiary amine compounds (US 2013016865), quaternary amine salts, and the like. However, the catalyst has a plurality of defects, such as difficult catalyst synthesis, large dosage, high-temperature reaction condition or difficult reaction temperature control, high color number, poor product selectivity and the like.

Therefore, a novel catalyst needs to be prepared, the catalyst has good catalytic effect, the catalyst dosage is low, the reaction temperature is stable, and the prepared isocyanate trimer product has low viscosity and good storage stability.

Disclosure of Invention

The invention aims to provide an isocyanate polymerization catalyst and a preparation method thereof. The catalyst system does not contain metal, has the characteristics of high activity, stable catalytic reaction process and simple and easy preparation method.

The invention also provides a preparation method of the polyisocyanate, which has the advantages of small catalyst consumption, stable reaction temperature, low viscosity of the prepared polyisocyanate, low color number and the like.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

an isocyanate polymerization catalyst having the structural formula:

Wherein X is selected from halogen ions such as fluorine, chlorine, bromine, iodide;

R ₁、R₂ represents identical or different branched or branched aliphatic, cycloaliphatic C1-C20 radicals, preferably C1-C10 aliphatic or cycloaliphatic substituents, more preferably methyl, ethyl, isopropyl, cyclohexyl, benzyl;

R ₃、R₄、R₅ represents identical or different linear or branched C1-C20 aliphatic, cycloaliphatic, aromatic or araliphatic radicals; or R ₃、R₄、R₅ is combined with a nitrogen atom to form a cyclic structure; preferably C1-C10 alkyl, cyclopentyl, cyclohexyl, phenyl containing substituents, or benzyl; further preferred are methyl, ethyl, isopropyl, butyl, cyclohexyl, phenyl, adamantyl and benzyl.

Specifically, the preparation method of the catalyst comprises the following steps:

in an inert solvent, dihalosilane is mixed with tertiary amine, stirred and reacted at 25-80 ℃, and then separated to obtain the catalyst.

Can be obtained by vacuum concentration or recrystallization by using acetone and n-hexane as solvents.

Preferably, the dihalosilane has the following structure:

Wherein x= F, cl, br, I; r ₁、R₂ is as defined above.

Preferably, the tertiary amine has the structural formula:

r ₃、R₄、R₅ is as defined above.

More preferably, the tertiary amine is one or more of triphenylamine, triisopropylamine, triethylamine, pyridine, triethylenediamine, N-methyl-N-ethylcycloylamine, N-benzyl-N-methyladamantane.

Preferably, the molar ratio of dihalosilane to tertiary amine is from 1:1 to 1:4, more preferably from 1:2 to 1:3.

Preferably, the reaction time is 1 to 6 hours, more preferably 2 to 4 hours.

Preferably, the reaction temperature is 25 to 100 ℃, more preferably 40 to 80 ℃.

Wherein the reaction solvent is inert solvent, and can be benzene, acetone, xylene, toluene, tetrahydrofuran, etc.

The preparation method of the catalyst can be expressed by the following equation:

wherein x= F, cl, br, I.

The catalyst of the invention can be used for preparing polyisocyanate.

A process for the preparation of a polyisocyanate comprising the steps of:

Under the inert gas atmosphere, at least one polyisocyanate is used as a raw material to carry out self-polymerization reaction under the catalysis of at least one catalyst shown in the formula I, so as to obtain isocyanate trimer.

Preferably, the polyisocyanate may be one or more of all polyisocyanates known in the art. Further preferred are one or more of Pentamethylene Diisocyanate (PDI), hexamethylene Diisocyanate (HDI), trimethyl-HDI (TMDI), 2-methylpentane 1, 5-diisocyanate (MPDI), isophorone diisocyanate (IPDI), 1, 3-and 1, 4-bis (isocyanatomethyl) cyclohexane (H6 XDI), bis (isocyanatomethyl) Norbornane (NBDI), 3 (4) -isocyanatomethyl-1-methyl-cyclohexyl isocyanate (IMCI) or 4,4' -bis (isocyanatocyclohexyl) methane (H12 MDI); more preferably one or more of H6XDI, PDI, HDI, IPDI.

Preferably, the catalyst is added in an amount of 10 to 800ppm, preferably 100 to 500ppm, more preferably 150 to 400ppm, based on the mass of the isocyanate raw material.

The catalyst prepared in the process of the present invention may be used in the form of a solution or without a solvent. Suitable solvents in principle comprise all substances which dissolve the catalyst without deteriorating it and do not participate in the isocyanate reaction or in the reaction but only in the production of polyurethane chemistry without destruction. If the catalyst is used in the form of a solution, the mass concentration of the catalyst is 10 to 70%, preferably 20 to 50%.

Further, the self-polymerization reaction temperature is 20 to 200 ℃, preferably 40 to 150 ℃, more preferably 50 to 100 ℃;

further, the reaction is terminated after the conversion of the polyisocyanate raw material reaches 10 to 70%, preferably 30 to 50%.

After the reaction is finished, an acid and/or an acid derivative can be optionally added as a terminator to deactivate the catalyst, and any other catalyst deactivation method known in the art can be used, wherein the acid and/or acid derivative comprises one or more of benzoyl chloride, phosphoric acid, benzene mesylate, phosphate, phosphite, p-toluenesulfonic acid and the like, and the molar ratio of the terminator to the catalyst is 0.6-1.1.

And removing residual isocyanate monomers from the partially trimerized reaction liquid after the catalyst deactivation by conventional prior art methods such as film evaporation, extraction, rectification and the like to obtain a polyisocyanate product, wherein the monomer content is lower than 0.5 weight percent.

The polyisocyanate prepared by the method has the advantages of high content of trimer reaching more than 50wt percent, preferably 55-75 wt percent, low content of high polymer, generally less than 8wt percent, low viscosity and excellent performance.

The polyisocyanate product obtained is in a solid or liquid state at room temperature, and can be directly diluted with a solvent or directly used. The solvent is selected from one or more of butyl acetate, ethyl acetate, xylene, propylene glycol methyl ether acetate and the like, and the solid content of the diluted product can be 50-80 wt%.

The polyisocyanate prepared by the invention can be used for preparing paint, coating compositions, adhesives and additives.

The polyisocyanates of the invention can be used as such or in combination with other prior art isocyanate derivatives, such as biurets, allophanates, carbamates, uretdiones, etc.

Compared with the existing catalyst, the disilicide salt catalyst has the advantages of stable reaction rate, controllable reaction temperature, low product viscosity, good product storage stability and the like.

Detailed Description

The method provided by the present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

About 5wt% (¹ H NMR) or about 50wt% (¹³ C NMR) of a sample of anhydrous deuterated solvent CDCl ₃ containing a trace amount of tetramethylsilane with a chemical shift value of ¹ H NMR of 0ppm was measured on a Brucker DPX 400 instrument at a frequency of 400 (¹ H NMR) or 100 (¹³ C-NMR).

Mass spectra were characterized using agilent 7890A-5975C.

The viscosity measurement method comprises the following steps: dynamic mechanical viscosity was measured using a BrookField DV-I Prime viscometer using an S21 spindle at 25 ℃.

The product colour number was determined using a colour number meter LCS IV from BYK company.

The NCO content was determined by titration according to DIN EN ISO 11909 using a titration instrument 905Titrando from Mettler.

The gel chromatography technology is used for quantifying the raw material isocyanate monomer, and is used as a monitoring means for judging the reaction conversion rate (calculated based on the mass of the raw material isocyanate monomer), wherein the steps of adopting the following chromatographic columns in series are adopted, wherein the chromatographic columns are LC-20AD/RID-10A, the chromatographic columns are MZ-Gel SDplus 10E3A 5um(8.0X300mm),MZ-Gel SDplus 500A 5um(8.0x 300mm),MZ-Ge1 SDp 1us 100A 5um(8.0x300mm), Shimadzu, the mobile phase is tetrahydrofuran, and the flow rate is 1.0mL/min; analysis time is 40min; the temperature of the chromatographic column is 35 ℃;

The trimer content and the high polymer content of the invention are all characterized by molecular gel chromatography.

Unless otherwise indicated, all reactions were carried out under a nitrogen atmosphere.

The isocyanate raw materials are all products of Wanhua H ₆ XDI;

the 1-benzyl-1-cyclohexyl dichlorosilane is prepared by polycondensation of 1-benzyl dichlorosilane and chlorocyclohexane, and the specific process is as follows: under nitrogen atmosphere and ice bath conditions, 1-benzyl dichlorosilane (1 mol) and 10mL of tetrahydrofuran are added into a reaction bottle, sodium hydride (1.1 eq) is slowly added, after stirring for 30min, chlorocyclohexane is slowly added into the reaction bottle in a dropwise manner, after the dropwise addition, the ice bath is removed, the temperature is returned to room temperature, stirring is carried out for 4h, and the reaction is stopped. After 10mL of 1M hydrochloric acid was added to the reaction flask, 3X 10mL of tetrahydrofuran was added for extraction, and the organic phase was distilled under reduced pressure to obtain the target product 1-benzyl-1-cyclohexyldichlorosilane. Wherein 1-benzyl dichlorosilane is purchased from Chongqing Jiete medical science and technology Co., ltd (HONGKONG CHEMHERE CO. LIMITED), chlorocyclohexane and sodium hydride are purchased from Allatin;

N-methyl-N-ethylcyclohexylamine is prepared from N-ethylmethylamine and chlorocyclohexane by the following procedure: n-ethylmethylamine (1 mol) and 10mL of tetrahydrofuran are added into a reaction bottle under nitrogen atmosphere and ice bath condition, a polycondensing agent triethylamine (1.1 eq) is added, after stirring for 10min, chlorocyclohexane is slowly added, after dripping, stirring is carried out for 4h, and the reaction is stopped. 10mL of 1M hydrochloric acid is added into the reaction solution, 3X 10mL of tetrahydrofuran is added for extraction, filtration is carried out, the filtrate is dried, and the target product N-methyl-N-ethyl cyclohexylamine is obtained by reduced pressure rotary evaporation. Wherein N-ethylmethylamine and chlorocyclohexane are purchased from aletin;

N-benzyl-N-methyladamantane is prepared from N-benzyl-methylamine and 1-chloroadamantane by the same method as N-methyl-N-ethylcyclohexylamine. N-benzyl methyl amine, 1-chloroadamantane purchased from Ala-dine;

Dimethyl dichlorosilane is purchased from aletin;

Dimethyl difluorosilane was purchased from Shanghai Kaijin chemical Co., ltd;

dimethyl dibromosilane is purchased custom from SAGECHEM LITIMED;

Dimethyl diiodosilane was purchased from Shenzhen Aituo chemical Co., ltd;

[ example 1 ]

Triethylamine (6 mmol,606 g) was slowly added dropwise to a solution of dimethyldichlorosilane (3 mmol,387 g) in acetone (10 mL). After stirring at room temperature for 3 hours, the reaction solution was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate out, followed by filtration and drying to obtain the objective product, designated as catalyst # 1.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ3.28(12H,q),1.56(18H,t),0.14(6H,s)。

¹³CNMR(100M,TMS):δ-11.1,9.4,47.3。

[M+H]⁺331.21(ESI)

[ example 2 ]

Triphenylamine (6 mmol,1472 g) was slowly added dropwise to a solution of dimethyldichlorosilane (3 mmol,387 g) in acetone (10 mL). After stirring at 50℃for 4 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to obtain the target product, designated as catalyst # 2.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ7.48～7.52(18H,m),7.38～7.44(12H,m),0.12(6H,s)。

¹³CNMR(100M,TMS):δ-12.3,128.7,130.5。

[M+H]⁺619.21(ESI)

[ example 3]

Pyridine (6 mmol,474.6 g) was slowly added dropwise to a solution of dimethyldibromosilane (3 mmol, 254 g) in acetone (15 mL). After stirring at 60℃for 5 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to give the target product, designated 3# catalyst.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ8.74～8.86(6H,m),8.22(4H,m),0.18(6H,s)。

¹³CNMR(100M,TMS):δ-6.3,128.4,142.5,146.1。

[M+H]⁺376.95(ESI)

[ example 4]

Triethylenediamine (6 mmol,673.08 g) was slowly added dropwise to a solution of dimethyldiiodosilane (3 mmol,936 g) in toluene (10 mL). After stirring at 70℃for 4 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to obtain the target product, designated as catalyst # 4.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ3.34(12H,m),2.80(12H,t),0.20(6H,s)。

¹³CNMR(100M,TMS):δ-8.2,53.9,58.1。

[M+H]⁺536.03(ESI)

[ example 5]

N-methyl-N-ethylcyclohexylamine (6 mmol,847.6 g) was slowly added dropwise to a toluene (10 mL) solution containing dimethyldichlorosilane (3 mmol,387 g). After stirring at 60℃for 5 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to give the target product, designated as catalyst # 5.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ3.52(2H,dt),3.28(4H,q),2.90(6H,s),1.72～1.97(8H,m),1.56(6H,t),1.42～1.48(12H,m),0.14(6H,s).

¹³CNMR(100M,TMS):δ-11.11,9.4,24.0,25.7,29.2,36.3,47.9,62.7。

[M+H]⁺411.27(ESI)

[ example 6]

N-benzyl-N-methyladamantane (6 mmol,1532.4 g) was slowly added dropwise to a solution of dimethyldichlorosilane (3 mmol,387 g) in toluene (10 mL). After stirring at 75℃for 6 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to give the target product, designated as catalyst # 6.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ7.16～7.25(10H,m),4.51(4H,s),2.90(6H,s),1.3～2.02(30H,m)，0.16(6H,s)。

¹³CNMR(100M,TMS):δ-11.0,26.4,29,36.6,37,49.0,54.6,58.4,59.0,61,125.7,128.6,129.0,132.6。

[M+H]⁺639.37(ESI)

[ example 7]

Triphenylamine (6 mmol,1472 g) was slowly added dropwise to a solution of 1-methyl-1-ethyldichlorosilane (3 mmol, 428 g) in acetone (10 mL). After stirring at 50℃for 4 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to obtain the target product, designated as catalyst # 7.

The catalyst structure characterization data are as follows:

¹HNMR(400M,TMS):δ7.04～7.35(30H,m),1.45(1H,m),0.97(6H,d),0.94(3H,s),0.67(2H,q)。

¹³CNMR(100M,TMS):δ-9.4,2.2,5.0,17.9,121.2,128.7,130.5,138.0。

[M+H]⁺661.26(ESI)

[ example 8]

Triphenylamine (6 mmol,1472 g) was slowly added dropwise to a solution of 1-benzyl-1-cyclohexyldichlorosilane (3 mmol,819.81 g) in toluene (10 mL). After stirring at 60℃for 4 hours, the reaction mixture was concentrated to 5mL in vacuo, and then n-hexane (15 mL) was added to precipitate a precipitate, which was then filtered and dried to give the target product, designated as catalyst # 8.

¹HNMR(400M,TMS):δ7.00～7.35(35H,m),1.89(2H,s),1.19～1.53(11H,m)。

¹³CNMR(100M,TMS):δ3.9,5.9,25.7,26.7,27.0,121.2,128.6,128.7,129.0,130.5,138,140.5

[M+H]⁺763.30(ESI)

The anionic and cationic structural expressions of the catalysts prepared in examples 1 to 8 are shown in Table 1, respectively:

TABLE 1 catalyst Structure Table

Test of catalyst Performance

1000G H ₆ XDI was placed in a round bottom flask equipped with a stirrer, a thermometer and a nitrogen inlet under anhydrous and anaerobic conditions, heated to 70℃in a water bath, and 1-8 ^# catalyst was added respectively and stirred continuously, and the ratio of the catalyst addition amount to the total mass of H ₆ XDI in different catalyst performance tests is shown in Table 2. And (3) observing the temperature rise condition in the reaction process, judging the reaction process by monitoring the monomer content value of the reaction liquid, and adding diisooctyl phosphate with the same molar quantity as the catalyst to terminate the reaction when the NCO content of the reaction liquid is between 22 and 24 weight percent.

And evaporating and removing monomers in the reaction liquid by using a thin film evaporator at a preheating temperature of 100 ℃ and a separation temperature of 140 ℃ under the absolute pressure of less than 200Pa to ensure that the monomer content is less than 0.5 weight percent, thereby obtaining the polyisocyanate product. The obtained product had a solids content of 75% with ethyl acetate, and the reaction results are shown in Table 2.

Comparative example 1

The catalyst of comparative example 1 was tetramethyl ammonium hydroxide, the rest of the procedure was the same as in example 6, and the reaction results are shown in Table 2.

Comparative example 2

The catalyst of comparative example 2 was tributylbenzyl ethyl ammonium caproate, and the other processes were the same as in example 6, and the reaction results are shown in Table 2.

Table 2 results of examples and comparative examples

The obtained H ₆ XDI trimer product has small maximum temperature rise by adopting silicon salt as a catalyst, stable reaction process, slightly low high polymer content, high trimer content, low product viscosity and good storage stability.

Claims (7)

1. An isocyanate polymerization catalyst having the structural formula:

Wherein X is selected from halogen ions such as fluorine, chlorine, bromine, iodide;

R ₁、R₂ represents identical or different branched or branched aliphatic, cycloaliphatic C1-C20 radicals, preferably C1-C10 aliphatic or cycloaliphatic substituents, more preferably methyl, ethyl, isopropyl, cyclohexyl, benzyl;

R ₃、R₄、R₅ represents identical or different linear or branched C1-C20 aliphatic, cycloaliphatic, aromatic or araliphatic radicals; or R ₃、R₄、R₅ is combined with a nitrogen atom to form a cyclic structure; preferably C1-C10 alkyl, cyclopentyl, cyclohexyl, phenyl containing substituents, or benzyl; further preferred are methyl, ethyl, isopropyl, butyl, cyclohexyl, phenyl, adamantyl and benzyl.

2. The method for preparing the catalyst according to claim 1, comprising the steps of:

Mixing dihalosilane and tertiary amine in an inert solvent, stirring at 25-80 ℃ for reaction, and separating to obtain the catalyst;

Preferably, the dihalosilane has the following structure:

Wherein x= F, cl, br, I; r ₁、R₂ is as defined above;

Preferably, the tertiary amine has the structural formula: r ₃、R₄、R₅ is as defined above.

3. The preparation method according to claim 2, wherein the tertiary amine is one or more of triphenylamine, triisopropylamine, triethylamine, pyridine, triethylenediamine, N-methyl-N-ethylcycloylamine, N-benzyl-N-methyladamantane;

preferably, the molar ratio of dihalosilane to tertiary amine is from 1:1 to 1:4, more preferably from 1:2 to 1:3;

preferably, the reaction time is 1 to 6 hours, more preferably 2 to 4 hours;

Preferably, the reaction temperature is 25 to 100 ℃, more preferably 40 to 80 ℃;

wherein the reaction solvent is an inert solvent selected from one or more of benzene, acetone, xylene, toluene or tetrahydrofuran.

4. A process for the preparation of a polyisocyanate, comprising the steps of:

Under the inert gas atmosphere, at least one polyisocyanate is used as a raw material to carry out self-polymerization reaction under the catalysis of the catalyst of claim 1 or the catalyst prepared by the preparation method of claim 2 or 3, so as to obtain isocyanate trimer.

5. The process according to claim 4, wherein the polyisocyanate is one or more selected from the group consisting of pentamethylene diisocyanate, hexamethylene diisocyanate, trimethyl-HDI, 2-methylpentane 1, 5-diisocyanate, isophorone diisocyanate, 1, 3-and 1, 4-bis (isocyanatomethyl) cyclohexane, bis (isocyanatomethyl) norbornane, 3 (4) -isocyanatomethyl-1-methyl-cyclohexyl isocyanate and 4,4' -bis (isocyanatocyclohexyl) methane;

Preferably, the catalyst is added in an amount of 10 to 800ppm, preferably 100 to 500ppm, more preferably 150 to 400ppm, based on the mass of the isocyanate raw material.

6. The production process according to claim 4 or 5, wherein the self-polymerization reaction temperature is 20 to 200 ℃, preferably 40 to 150 ℃, more preferably 50 to 100 ℃;

preferably, the reaction is terminated after the polyisocyanate starting material conversion reaches 10 to 70%, preferably 30 to 50%.

7. The preparation method according to claim 4 or 5, wherein after the reaction, an acid and/or an acid derivative including one or more of benzoyl chloride, phosphoric acid, a benzenesulfonate, a phosphate, a phosphite, and p-toluenesulfonic acid is optionally added as a terminator to deactivate the catalyst, the molar ratio of the terminator to the catalyst being 0.6 to 1.1.