CN1080590C - Double metal cyanide catalyst and its prepn. method - Google Patents

Abstract

A double metal cyanide catalyst, the composition of the catalyst is Zn ₃ [Co(CN) ₆ ] ₂ · aZnCl ₂ · bH ₂ O · cL · dL', wherein L is an organic alcohol, L' is an organic ether , a mixture of zinc salt and hexacyanocobaltate was treated with a mixture of ether/alcohol to obtain a precipitate, which was washed and dried in vacuum to obtain a catalyst. The DMC catalyst has the advantages of easy separation from polyether polyols, low use concentration, simple preparation method and the ability to synthesize polyether polyols with low unsaturation in a wide temperature range.

Description

A kind of double metal cyanide catalyst and preparation method thereof

The invention belongs to catalysts, in particular to a double metal cyanide catalyst and a preparation method thereof.

The use of double metal cyanide complex catalysts in the polymerization of epoxides is well known. Compared with polyether polyols synthesized by KOH, DMC polyether polyols with the same molecular weight have lower unsaturation. Since polyether polyol is an intermediate in the synthesis of polyurethane, the degree of unsaturation of polyether polyol directly affects the performance of polyurethane products, so DMC polyether polyol has broad development potential in the field of polyurethane. With the improvement of performance requirements, the development of high-performance double metal cyanide catalysts has become a hot topic in the field of polyurethane research.

DMC compounds refer to compounds with the structure Ma[M'(CN)b(A)c]d, wherein M and M' are metal ions, A is a ligand other than ^CN- , a, b, c, d is a coefficient, b>c. It was found that some double metal cyanides were treated with some organic substances to obtain DMC catalysts that can catalyze the polymerization of epoxides. Since the U.S. General Tire & Rubber Company first applied for a patent in the 1960s, there have been a series of patents related to DMC catalysts, such as USPat 3,278,457. 3,278,458. 3,404,109. 3,427,256. .The common ground of these patents is: (1) the DMC compound that is used to prepare DMC catalyst mainly is zinc hexacyanoferrate (Zn ₃ [Fe(CN) ₆ ] ₂ ), zinc hexacyanocobaltate (Zn ₃ [Co( CN) ₆ ] _2. Since zinc hexacyanocobaltate is yellow, it has been replaced by zinc hexacyanocobaltate, and the patents in recent years all use zinc hexacyanocobaltate to prepare DMC catalyst; (2) DMC compounds are all based on a metal It is prepared by reacting a concentrated aqueous solution of salt with a dilute solution of another metal cyanide complex salt. The commonly used zinc hexacyanocobaltate is composed of a concentrated solution of zinc chloride and a dilute solution of potassium hexacyanocobaltate or calcium hexacyanocobaltate Prepared by reaction, in order to make the reaction complete, zinc chloride needs to be excessive. During preparation, zinc chloride solution can be added in potassium hexacyanocobaltate solution, and potassium hexacyanocobaltate solution can also be added in zinc chloride solution (3) process DMC compound with organic ligand. Existing patent generally adopts a kind of organic matter to process DMC compound, for example USPat 3,404,109 processes DMC compound with dioxane, acetone, ethylene glycol dimethyl ether respectively; USPat 3.427, 256 Treat DMC compounds with diethylene glycol diethyl ether, triethylene glycol diethyl ether, and diethylene glycol dimethyl ether respectively; USPat 5.482,908 treats DMC compounds with polyether diols with a molecular weight greater than 500; Jan.Pat 4-145,123 treated the DMC compound with tert-butanol.

The treatment of organic matter has a great influence on the performance of DMC catalysts. The DMC compound without organic matter treatment has a higher crystallinity, generally not less than 35%, and its catalytic performance is poor. The crystallinity of the DMC compounds treated with organic matter is reduced in different degrees, and its catalytic activity is improved and enhanced in different degrees. The performance of DMC catalysts is different due to the different organic matter used.

The DMC catalysts of these inventions can be well dissolved or dispersed in polyether polyols with tiny particles, but are difficult to remove, and the appearance of polyether polyols is turbid.

The invention purpose of the present invention is to provide a kind of double metal cyanide catalyst that is easy to separate from product and preparation method thereof.

The composition of catalyst of the present invention is as follows:

Zn ₃ [Co(CN) ₆ ] ₂ ·aZnCl ₂ ·bH ₂ O·cL·dL′

Wherein L is an organic alcohol, L' is an organic ether, a, b, c, d are coefficients, a=0.05-1.0, b=1.0-2.0, c=0.5-3.0, d=1.0-4.0.

The organic alcohols mentioned above are C4-C10 organic alcohols with a tertiary alcohol structure, preferably tert-butanol and tert-amyl alcohol.

The above-mentioned organic ether is an organic ether containing 2-4 ether oxygen bonds, preferably ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, Diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether.

The preparation method of catalyst as mentioned above is as follows:

a. Add concentrated zinc salt aqueous solution, dilute alkali metal or alkaline earth metal hexacyanocobaltate aqueous solution, alcohol, and ether into the reactor at the same time, stir evenly, form a precipitate, and separate. Wherein the addition amount of material is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- = (2-5): 1 (molar ratio)

Alcohol: ether = (0.1-10): 1 (volume ratio)

Add 4-15 liters of organic matter per mole of [Co(CN) ₆ ] ^3-

b. the separated precipitate is carried out slurry washing with the mixture of the same amount of organic matter and the water equal to 1/15～1/4 of the volume of organic matter added in the step (a), and the precipitate is separated,

c. The separated precipitate is then slurried and washed with the same amount of organic matter as in step (a), and the separated precipitate is vacuum-dried to constant weight at a temperature of 60° C. to obtain a catalyst.

The zinc salts mentioned above are inorganic zinc salts.

Zinc salts as mentioned above are preferably zinc chloride, zinc bromide, zinc nitrate, zinc sulfate.

The above-mentioned hexacyanocobaltate is preferably potassium hexacyanocobaltate, sodium hexacyanocobaltate.

The DMC catalyst prepared by the invention can be used to prepare random or block copolymers, and polyether polyols can be prepared in the presence of hydroxyl initiators. The epoxides used in the preparation of polyether polyols are preferably ethylene oxide, propylene oxide, butylene oxide, styrene oxide.

DMC catalyst of the present invention has following advantage compared with existing technology:

(1) The DMC catalyst is agglomerated and precipitated after the reaction to form polyether polyol, which is easy to separate.

(2) The degree of unsaturation of the polyether polyol prepared by the DMC catalyst is not higher than 0.007meq/g, which is 50% lower than the degree of unsaturation of the polyether polyol prepared by the DMC catalyst provided by the prior art.

(3) When the DMC catalyst is used at a concentration not higher than 200ppm, the conversion rate of the polymerization reaction is higher than 90%.

(4) The catalyst can be used in the temperature range of 0-200°C.

(5) The preparation method is simple.

Example 1

a. Dissolve 5.1g potassium hexacyanocobaltate in 100ml deionized water to obtain 0.15mol/l potassium hexacyanocobaltate solution; dissolve 10.0g zinc chloride in 20ml deionized water to obtain 3.67mol/l chlorine Zinc solution, while adding 180ml tert-butanol, 20ml ethylene glycol dimethyl ether, potassium hexacyanocobaltate solution, and zinc chloride solution into the reactor and stir evenly to form a precipitate and separate it; the amount of materials added is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝4.9:1 (molar ratio)

Tert-butanol: ethylene glycol dimethyl ether = 9: 1 (volume ratio)

13.3 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 180ml tert-butanol, 20ml ethylene glycol dimethyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 180 ml of tert-butanol and 20 ml of ethylene glycol dimethyl ether, and the separated precipitate was vacuum-dried to constant weight at a temperature of 60° C. to obtain catalyst A. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(CN) ₆ ] ₂ ·0.093 ZnCl ₂ ·2.7C ₄ H ₁₀ O ·1.2C ₄ H ₁₀ O ₂ .

Example 2

a. Dissolve 5.3g potassium hexacyanocobaltate in 40ml deionized water to obtain 0.4mol/l potassium hexacyanocobaltate solution; dissolve 8.7g zinc chloride in 20ml deionized water to obtain 3.2mol/l chlorine Add zinc solution, 60ml tert-amyl alcohol, 10ml ethylene glycol diethyl ether, potassium hexacyanocobaltate solution, and zinc chloride solution into the reactor and stir evenly to form a precipitate and separate it; wherein the amount of material added is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝4.0:1 (molar ratio)

Tert-amyl alcohol: ethylene glycol diethyl ether = 6.0: 1 (volume ratio)

4.4 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 60ml tert-amyl alcohol, 10ml ethylene glycol diethyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 60 ml of tert-amyl alcohol and 10 ml of ethylene glycol diethyl ether, and the separated precipitate was vacuum-dried to constant weight at a temperature of 60° C. to obtain catalyst B. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(CN) ₆ ] ₂ ·0.076 ZnCl ₂ ·2.5C ₅ H ₁₂ O ·1.9C ₆ H ₁₄ O ₂ .

Example 3

a. Dissolve 4.0g calcium hexacyanocobaltate in 120ml deionized water to obtain a 0.06mol/l calcium hexacyanocobaltate solution; dissolve 8.7g zinc nitrate hexahydrate in 20ml deionized water to obtain a 2.6mol/l solution Zinc nitrate solution, simultaneously 112ml tert-butanol, 38ml diethylene glycol dimethyl ether, calcium hexacyanocobaltate solution, zinc nitrate solution are added in the reactor and stirred evenly, generate precipitation, separate; Wherein the addition of material is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝3.6:1 (molar ratio)

tert-butanol: diethylene glycol dimethyl ether = 3: 1 (volume ratio)

8.2 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 112ml tert-butanol, 38ml diethylene glycol dimethyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 112 ml of tert-butanol and 38 ml of diethylene glycol dimethyl ether, and the separated precipitate was vacuum-dried to constant weight at a temperature of 60° C. to obtain catalyst C. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(CN) ₆ ] ₂ ·0.065 ZnCl ₂ ·1.7C ₄ H ₁₀ O ·2.8C ₆ H ₁₄ O ₃ .

Example 4

a. Dissolve 6.0g calcium hexacyanocobaltate in 50ml deionized water to obtain a 0.2mol/l calcium hexacyanocobaltate solution; dissolve 20.8g zinc nitrate hexahydrate in 20ml deionized water to obtain a 3.5mol/l solution Zinc nitrate solution, 130ml tert-amyl alcohol, 130ml diethylene glycol diethyl ether, calcium hexacyanocobaltate solution, zinc nitrate solution are added in the reactor and stirred evenly, generate precipitation, separate; Wherein the addition of material is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝3.2:1 (molar ratio)

Tert-amyl alcohol: diethylene glycol diethyl ether = 1: 1 (volume ratio)

13.0 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 130ml tert-amyl alcohol, 130ml diethylene glycol diethyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 130 ml of tert-amyl alcohol and 130 ml of diethylene glycol diethyl ether, and the separated precipitate was vacuum-dried to constant weight at a temperature of 60° C. to obtain catalyst D. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(Cn) ₆ ] ₂ ·0.081 ZnCl ₂ ·0.8C ₅ H ₁₂ O ·3.0C ₈ H ₁₈ O ₃ .

Example 5

a. Dissolve 4.8g sodium hexacyanocobaltate in 60ml deionized water to obtain 0.26mol/l sodium hexacyanocobaltate solution; dissolve 9.9g zinc bromide in 20ml deionized water to obtain 2.2mol/l bromine Zinc solution, while adding 20ml tert-butanol, 80ml diethylene glycol dibutyl ether, sodium hexacyanocobaltate solution, and zinc bromide solution into the reactor and stir evenly to form a precipitate and separate it; the amount of material added is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝2.6:1 (molar ratio)

Tert-butanol: diethylene glycol dibutyl ether = 1:4 (volume ratio)

6.2 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 20ml tert-butanol, 80ml diethylene glycol dibutyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 20 ml of tert-butanol and 80 ml of diethylene glycol dibutyl ether, and the separated precipitate was vacuum-dried to constant weight at 60° C. to obtain catalyst E. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(CN) ₆ ] ₂ ·0.052 ZnCl ₂ ·0.6C ₄ H ₁₀ O ·3.3C ₁₂ H ₂₆ O ₃ .

Example 6

a. Dissolve 7.7g sodium hexacyanocobaltate in 90ml deionized water to obtain 0.3mol/l sodium hexacyanocobaltate solution; dissolve 13.5g zinc bromide in 20ml deionized water to obtain 3.0mol/l bromine Zinc solution, while adding 50ml tert-amyl alcohol, 350ml triethylene glycol dimethyl ether, sodium hexacyanocobaltate solution, and zinc bromide solution into the reactor and stir evenly to form a precipitate and separate it; wherein the amount of material added is:

Zn ²⁺ : [Co(CN) ₆ ] ^3- ＝2.2:1 (molar ratio)

tert-amyl alcohol: triethylene glycol dimethyl ether = 1: 7 (volume ratio)

14.7 liters of organic matter added per mole of [Co(CN) ₆ ] ^3-

b. The separated precipitate is slurried and washed with a mixture of 50ml tert-amyl alcohol, 350ml triethylene glycol dimethyl ether and 20ml water, and the precipitate is separated;

c. The separated precipitate was then slurried and washed with 50 ml of tert-amyl alcohol and 350 ml of triethylene glycol dimethyl ether, and the separated precipitate was vacuum-dried to constant weight at 60° C. to obtain catalyst F. Analysis indicated that the catalyst had the following composition: Zn ₃ [Co(CN) ₆ ] ₂ ·0.073 ZnCl ₂ ·0.6C ₅ H ₁₂ O ·3.7C ₈ H ₁₈ O ₄ .

Example 7

Synthesis of Polyether Polyols

In 2 liters of reactors, add 68.6g molecular weight to be 700 polypropylene oxide triols or polypropylene oxide diols and 0.164g catalyst, be warming up to reaction temperature under stirring, after vacuumizing dehydration, add 10g propylene oxide, wait When the pressure in the reactor drops significantly, slowly add propylene oxide, the speed of adding is based on maintaining the pressure in the reactor at about 40psi, and the amount of propylene oxide added is determined by the molecular weight of polyether polyol. Finally, when the pressure in the reactor is constant, the reaction is over, and the unreacted propylene oxide is removed by vacuum, and the reaction product is filtered through a filter with a pore size of 0.45-1.2u at a temperature of 100°C to obtain a polyether polyol.

The reaction temperature, conversion rate and the properties of polyether polyol are shown in Table 1, and the residual amount of catalyst in polyether polyol is shown in Table 2.

Table 1 Table of catalyst reaction temperature (℃) conversion rate ( %) hydroxy (mgkoh/g) Powerfulness unsaturation (MEQ/G) A 60> 98 29.8 3 0.0021a 105> 98 30.2 3 0.0028b 105> 98 29.5 3 0.0030B 150> 95 15.8 2 0.0054c 30> 95 28.4 3 0.0018d 80> 98 27.7 3 0.0023e 105> 98 15.6 2 0.0032F 125> 98 30.53 0.0036

Table 2 Catalyst hydroxy (mgkoh/g) Powerful catalyst dosage (PPM) residual zinc (PPM) residual cobalt (PPM) A 29.8 3 200 <5 <2A 30.2 3 100 <4 <29.5 3 200 <5 <2B 15.8 2 100 <4 2c 28.4 3 100 <4 <27.7 3 100 <4 <2e 15.6 2 100 <4 <2F 30.5 3 100 <4 <2

Claims (9)

1. a double metal cyanide catalyst is characterized in that the composition of the catalyst is as follows: Zn ₃ [Co(CN) ₆ ] ₂ ·aZnCl ₂ ·bH ₂ O·cL·dL′ Wherein L is an organic alcohol, L' is an organic ether, a, b, c, d are coefficients, a=0.05-1.0, b=1.0-2.0, c=0.5-3.0, d=1.0-4.0. 2. a kind of double metal cyanide catalyst according to claim 1 is characterized in that described organic alcohol is the organic alcohol of the C4-C10 that has tertiary alcohol structure. 3. a kind of double metal cyanide catalyst according to claim 1 is characterized in that described organic alcohol is tert-butyl alcohol or tert-amyl alcohol. 4. A double metal cyanide catalyst according to claim 1, characterized in that said organic ether is an organic ether containing 2-6 ether oxygen bonds. 5. a kind of double metal cyanide catalyst according to claim 1 is characterized in that described organic ether is ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol Dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, or triethylene glycol dimethyl ether. 6. a preparation method of double metal cyanide catalyst, is characterized in that following steps: a. Add the aqueous solution of concentrated zinc salt, the dilute aqueous solution of alkali metal or alkaline earth metal hexacyanocobaltate, alcohol and ether into the reactor at the same time, stir evenly, generate precipitation, and separate; wherein the addition amount of materials is: Zn ²⁺ : [Co(CN) ₆ ] ^3- = (2-5): 1 (molar ratio) Alcohol: ether = (0.1-10): 1 (volume ratio) Add 4-15 liters of organic matter per mole of [Co(CN) ₆ ] ^3- b. the separated precipitate is carried out slurry washing with the mixture of the same amount of organic matter and the water equal to 1/15～1/4 of the volume of organic matter added in the step (a), and the precipitate is separated, c. The separated precipitate is then slurried and washed with the same amount of organic matter as in step (a), and the separated precipitate is vacuum-dried to constant weight at a temperature of 60° C. to obtain a catalyst. 7. the preparation method of a kind of double metal cyanide catalyst according to claim 6 is characterized in that described zinc salt is inorganic zinc salt. 8. the preparation method of a kind of double metal cyanide catalyst according to claim 6 is characterized in that described zinc salt is zinc chloride, zinc bromide, zinc nitrate or zinc sulfate. 9. The preparation method of a double metal cyanide catalyst according to claim 6, characterized in that said hexacyanocobaltate is potassium hexacyanocobaltate or sodium hexacyanocobaltate.