CN111303380B

CN111303380B - Preparation method and application of polyurea polyol capable of releasing carbon dioxide

Info

Publication number: CN111303380B
Application number: CN202010199861.2A
Authority: CN
Inventors: 李付国; 刘洋; 秦承群; 鞠昌迅; 刘斌; 吕树卫
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2022-03-11
Anticipated expiration: 2040-03-20
Also published as: CN111303380A

Abstract

The invention provides a preparation method of polyurea polyol capable of releasing carbon dioxide. The adopted raw materials are polyether polyol, hydrazine hydrate and diisocyanate, and the method comprises the following steps: (1) polyether polyol and hydrazine are uniformly mixed to obtain a mixture; (2) adding diisocyanate into the mixture for reaction; (3) removing residual diisocyanate monomer in the product to obtain the polyurea polyol. The polyurea polyol can release carbon dioxide when preparing polyurethane foam, thereby reducing the amount of the foaming agent used, and the obtained foam has high hardness.

Description

Preparation method and application of polyurea polyol capable of releasing carbon dioxide

Technical Field

The invention belongs to the field of polyurethane, and particularly relates to a preparation method and application of polyurea polyol capable of releasing carbon dioxide.

Background

Polyurethane foams are prepared by reacting polyisocyanates and polyols in the presence of blowing agents, and various modified polyol products have been developed for the purpose of improving load-bearing and other properties. A commonly used type is a dispersion of polymer particles in a polyol, such as polyurea particle dispersions (PHD polyols), which are white or beige viscous liquids, mainly used for molded products, which, in addition to having the characteristics of a common POP (polymer polyol), has many other advantages: good flame retardant property, high foam bearing load, high speed of increasing initial gel of foam and good foam stability.

In the prior art, two methods are generally used for the preparation of polyurea polyols: batch or continuous production processes. The batch production method is mainly characterized in that isocyanate is gradually dripped into a polyol/polyamine mixed system at a slow speed under the condition of rapid stirring to prepare polyurea polyol, as described in US3325421, the viscosity is high, the solid content is 10 percent, and the viscosity is more than 10,000mPa & s/25 ℃; the continuous production process includes pumping polyamine, polyol and isocyanate into mixer at different speed, high speed stirring for instantaneous mixing reaction, and eliminating monomer to obtain the product. US4089835 discloses the continuous production of polyurea polyols having a solids content of 10% and a viscosity of around 2500 mPa.s/25 ℃. However, the polyurea polyols prepared by the methods do not have the function of releasing carbon dioxide, and the effect of improving the physical properties of downstream foams is not obvious.

Therefore, in view of reducing the amount of blowing agent and improving the application properties of the foam, it is necessary to develop a polyurea polyol which can release carbon dioxide and improve the application properties of the downstream foam, for the synthesis of polyurethane foam.

Disclosure of Invention

The present invention is directed to a method for preparing a polyurea polyol and use thereof, and more particularly, to a process for preparing a polyurea polyol which can generate carbon dioxide during foaming, and from which carbon dioxide can be released when preparing a polyurethane foam, thereby reducing the amount of a foaming agent used and improving the hardness of the foam.

The purpose of the invention is realized by the following technical scheme:

a method for preparing a carbon dioxide-releasable polyurea polyol, the method comprising the steps of:

(1) polyether polyol and hydrazine are uniformly mixed to obtain a mixture;

(2) adding diisocyanate into the mixture obtained in the step (1) for reaction;

(3) and (3) removing residual diisocyanate monomer in the product of the step (2) to obtain polyurea polyol.

In the invention, the polyether polyol obtained in the step (1) is obtained by taking micromolecule polyol with functionality of 2-6 as an initiator and carrying out ring-opening polymerization on propylene oxide and ethylene oxide; preferably, the ethylene oxide accounts for 5-20% of the total weight of the ethylene oxide and the propylene oxide, and the ethylene oxide accounts for 8-15%; preferably, the hydroxyl value of the polyether polyol is 10-80 mgKOH/g, preferably 20-40 mgKOH/g.

In the present invention, the hydrazine in the step (1) is anhydrous hydrazine and/or hydrazine hydrate, preferably hydrazine hydrate.

In one embodiment, the polyether polyol and hydrazine are mixed uniformly in step (1), and stirring, spraying, ultrasonic treatment, grinding and the like operations well known in the art can be selected, preferably by stirring; the mixing time is preferably 1 to 15 minutes.

In another embodiment, a solvent or a dispersant, such as one or more of water, lower alcohol, aromatic hydrocarbon, ketone, ester, amide, saturated aliphatic hydrocarbon and chloroalkane, preferably one or more of water, toluene, ethyl acetate, acetone and benzene, may be added in the step (1) as required.

In the present invention, the diisocyanate in step (2) is diisocyanate a containing an oxadiazinone structure, or a mixture of diisocyanate a and diisocyanate B, preferably a mixture of diisocyanate a and diisocyanate B.

In the invention, the diisocyanate A is obtained by reacting isocyanate containing C6-C12 alkyl substituent groups with carbon dioxide; preferably, the diisocyanate A is obtained by reacting one or more of hexamethylene diisocyanate, cyclohexane methyl diisocyanate and tetramethyl butane diisocyanate with carbon dioxide.

In the invention, the structural formula of the oxadiazinone of the diisocyanate A containing the oxadiazinone structure is as follows:

wherein M represents a C6-C12 alkyl-substituted group, preferably a saturated aliphatic hydrocarbon or a saturated alicyclic hydrocarbon fragment, and more preferably hexamethylene; wherein n is a statistical value, 0< n <4, and may be an integer or a non-integer.

In the present invention, the diisocyanate B in step (2) is an aliphatic isocyanate and/or an aromatic polyisocyanate, preferably one or more of m-phenylene diisocyanate, p-phenylene diisocyanate (PPDI), polymethine polyphenyl polyisocyanate, 2, 4-Toluene Diisocyanate (TDI), 2, 6-toluene diisocyanate, naphthalene diisocyanate, diphenylmethane 4,4 '-diisocyanate (MDI), diphenylmethane 2, 4-diisocyanate, diphenylmethane 2, 2' -diisocyanate and Hexamethylene Diisocyanate (HDI), more preferably a mixture of 2, 4-toluene diisocyanate and 2, 6-toluene diisocyanate.

In the invention, the weight ratio of the diisocyanate to the polyether polyol in the step (2) is (0.05-0.45): 1.

In the invention, the mole number of NCO in diisocyanate and NH of hydrazine in the step (2)₂The molar ratio of the radicals is (0.8-1.2): 1.

In one embodiment, the stirring device in the step (2) preferably uses a high-speed dispersion stirrer, and the speed is preferably 500-8000 r/min; the reaction temperature in the step (2) is 20-60 ℃, and preferably 25-45 ℃.

In another embodiment, in the step (3), the residual monomer is removed preferably under a higher temperature vacuum condition, and the preferred process is a gauge pressure vacuum degree of-0.1 MPa, and the temperature is 20-60 ℃, preferably 30-50 ℃.

Another object of the present invention is to provide a polyurea polyol.

The polyurea polyol capable of releasing carbon dioxide is prepared by the preparation method.

The polyurea polyol prepared by the invention has an oxadiazinone structure and does not react with hydroxyl under normal conditions, but when a polyurethane catalyst (such as an organic metal catalyst or an amine catalyst) is added in a foaming process, the catalyst can catalyze the reaction of oxadiazinone and hydroxyl, so that oxadiazinone is decomposed to generate carbon dioxide and allophanate, the using amount of a polyurethane foam foaming agent can be reduced, and the same foam height or even higher foam initiation degree is maintained.

It is yet another object of the present invention to provide a polyurethane foam.

The polyurethane foam is prepared by adopting the polyurea polyol as a raw material. The polyurea polyol is used for preparing polyurethane foam, and the polyurea polyol and isocyanate C are reacted with or without adding a foaming agent in the presence of a polyurethane catalyst and a crosslinking agent.

In the present invention, the isocyanate C is one or more of aliphatic isocyanate or aromatic polyisocyanate such as m-phenylene diisocyanate, p-phenylene diisocyanate (PPDI), polymethine polyphenyl polyisocyanate, 2, 4-Toluene Diisocyanate (TDI), 2, 6-toluene diisocyanate, naphthalene diisocyanate, diphenylmethane 4,4 '-diisocyanate (MDI), diphenylmethane 2, 4-diisocyanate, diphenylmethane 2, 2' -diisocyanate, Hexamethylene Diisocyanate (HDI), and polymeric diphenylmethane diisocyanate (PMDI); the polyurea polyol is used in an amount of 10 to 110 wt.%, based on the total mass of the isocyanate C.

In one embodiment, the polyurethane catalyst is preferably a substance that can accelerate the reaction of the oxadiazinone with the hydroxyl group, and specific examples include metal catalysts such as stannous octoate, stannous oleate, dibutyltin dilaurate, dibutyltin diacetate, and amine catalysts such as trimethylamine, triethylamine, Triethylenediamine (TEDA), dimethylethanolamine, and bis (2, 2-dimethylamino) -ethyl ether. The amount of the polyurethane catalyst is 0.015-5 wt% relative to the polyurea polyol.

In one embodiment, if a cross-linking agent is used, glycerol and diethanolamine are useful. The amount of the cross-linking agent is 0.1-5 wt% relative to the polyurea polyol.

In one embodiment, suitable blowing agents include water, acetone, carbon dioxide, halogenated hydrocarbons, aliphatic alkanes and cycloalkanes. The amount of the foaming agent is 2-25 wt% relative to the polyurea polyol.

In one embodiment, as further additives that may be added, flame retardants, surfactants, fillers, dyes or pigments may also be used.

In the invention, the vacuum pressure is gauge pressure.

The polyurea polyol prepared by the invention has the following positive effects: the polyurea polyol has an oxadiazinone structure, and the oxadiazinone is decomposed to generate carbon dioxide and allophanate, so that the using amount of the polyurethane foam foaming agent can be reduced to 25-75% of the original using amount, and the same foam height and even higher foam inspiration are maintained.

Detailed Description

The present invention will be described in detail by way of specific examples. The scope of the invention is not limited by the specific embodiments.

The compounds and instruments or standards used in the present invention are described below:

the base polyether polyol is high resilience soft foam polyether polyol prepared by the reaction of glycerol, propylene oxide and ethylene oxide, and is a product of Wanhua chemical group Limited company, and the hydroxyl value is 28.0 +/-1.5 mgKOH/g;

the base polyether polyol is high resilience soft foam polyether polyol prepared by the reaction of glycerol, propylene oxide and ethylene oxide, and is a product of Wanhua chemical group Limited company, and the hydroxyl value is 35.0 +/-1.5 mgKOH/g;

basic polyether polyol, common soft foam polyether polyol prepared by the reaction of glycerol, propylene oxide and ethylene oxide, a product of Wanhua chemical group Limited company, and a hydroxyl value of 56.0 +/-1.5 mgKOH/g;

HZDI-1: a diisocyanate A. HDI and carbon dioxide react to refine a product, refer to patent GB11459522, 336g of HDI is added into a closed container, 30g of carbon dioxide is introduced, the temperature is raised to 60 ℃, 1.7g of tributylamine is added to maintain the reaction for 1.5 hours, 1.5g of dimethyl sulfate is added to stop the reaction, and unreacted monomers are removed to obtain 92g of light yellow oily liquid, wherein the NCO content is 21.5%, and n is 1;

HZDI-2: a diisocyanate A. Refining a product by reacting HDI with carbon dioxide, wherein the method is shown in GB11459522 and is the same as HZDI-1, the NCO content is 19.7 percent, and n is 1.2;

the product of Wanhua chemical group Limited company, with purity more than or equal to 99.5% and 2,4-TDI content more than or equal to 98.0%, is used as diisocyanate B;

the product of Wanhua chemical group Limited company, with purity more than or equal to 99.5% and 2,4-TDI content more than or equal to 80.0%, is used as diisocyanate C;

hydrazine hydrate: 80% mass concentration aqueous solution, and an avastin reagent;

diethanolamine: purity > 99%, alatin;

n, N-bis (dimethylaminopropyl) isopropanolamine: purity > 99%, alatin;

n, N '-trimethyl-N' -hydroxyethyl bisaminoethyl ether: purity > 99%, alatin;

BiCAT 8106: bi content is 20%, and the U.S. advanced chemistry is adopted;

b-8715LF 2: the company high schmitt in germany,

LF2, open-cell high-resilience silicone oil.

The stirrer: shanghai precision instruments & meters, Inc., model SF 450;

viscometer: brooks technologies, Inc., DV-I + prime viscometer, 4# rotor;

foam hardness: GB/T10807-2006 determination of the hardness of flexible foam Polymer materials (indentation method) (idt ISO2439: 1997).

Example 1

365g of the mixture is added into a four-neck flask

And 3.46g of hydrazine hydrate, continuously stirring at room temperature for 5 minutes; then the rotation speed is increased to 6000r/m, 36.5g of isocyanate HZDI-1 which is mixed and shaken for 1 minute is added into the mixture within 30 seconds, the stirring is continued for 30 minutes, and the temperature is kept during the periodAt the temperature of 40 ℃, vacuumizing for 2.5 hours under the conditions that the pressure is-0.1 MPa and the temperature is 45 ℃ to obtain a polyurea polyol product with the solid content of 9.5 percent and the viscosity of 1850cp @25 ℃.

Example 2

365g of the mixture is added into a four-neck flask

And 21.9g of hydrazine hydrate, continuously stirring at room temperature for 5 minutes; then the rotation speed is increased to 6000r/m, and 36.5g of isocyanate HZDI-1 which are mixed and shaken for 1 minute are added into the mixture within 30 seconds

The TDI-100 mixture was further stirred for 30 minutes while maintaining the temperature at 40 ℃ and evacuating at-0.1 MPa and 45 ℃ for 2.5 hours to obtain a polyurea polyol product having a solids content of 29.6% and a viscosity of 5201cp @25 ℃.

Example 3

365g of the mixture is added into a four-neck flask

And 8.6g of hydrazine hydrate, continuously stirring for 5 minutes at normal temperature; then the rotation speed is increased to 6000r/m, 91.25g of isocyanate HZDI-2 which is mixed and shaken for 1 minute is added into the mixture within 30 seconds, the mixture is continuously stirred for 30 minutes, the temperature is kept at 40 ℃, and the vacuum pumping is carried out for 2.5 hours under the conditions that the pressure is minus 0.1MPa and the temperature is 45 ℃ to obtain the polyurea polyol product, the solid content is 20.5 percent, and the viscosity is 3806cp @25 ℃.

Comparative example 1

Refer to CN 03126824.2.

264g of the mixture was placed in a four-necked flask

And 11.5g of hydrazine hydrate, continuously stirring for 5 minutes at normal temperature; 30.5g of the mixture after shaking for 1 minute was added to the above mixture over 30 seconds

The TDI-100 mixture and 101.6g of polyether polyol were further stirred for 30 minutes, during which time the temperature was maintained at 40 ℃ and the vacuum was applied at-0.1 MPa and 45 ℃ for 2.5 hours to obtain a polyurea polyol product having a solids content of 10.0% and a viscosity of 4218cp @25 ℃.

Example 4

Preparing polyurethane foam. Preparing a combined material according to the raw materials and parts by weight shown in Table 1, and respectively placing the combined material and the isocyanate raw material in an environment with the temperature of 22 ℃ for 3 hours. Then 100g of the combined materials are respectively taken and mixed with 52g of the combined materials

TDI-80 was stirred and mixed in a stirrer (rotational number 3000rpm) for 6 seconds. The stirred mixture was then rapidly poured into an aluminum open mold (size: 300mm in length, 300mm in width, 50mm in thickness) previously heated to 60 ℃ to foam the mixture. And after 7 minutes, taking out the foam to obtain the polyurethane foam.

TABLE 1 polyurethane foam composition formula

The performance indexes of the prepared polyurethane foam are shown in the table 2:

TABLE 2 polyurethane foam Properties

It will be appreciated by those skilled in the art that modifications or adaptations to the invention may be made in light of the teachings of the present specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined in the claims.

Claims

1. A method for preparing a carbon dioxide-releasable polyurea polyol, comprising the steps of:

(1) polyether polyol and hydrazine are uniformly mixed to obtain a mixture;

(2) adding diisocyanate into the mixture obtained in the step (1) for reaction;

(3) removing residual monomers in the product obtained in the step (2) to obtain polyurea polyol;

wherein, the diisocyanate in the step (2) is diisocyanate A containing oxadiazinone structure or a mixture of diisocyanate A and diisocyanate B;

wherein, the structural formula of the oxadiazinone of the diisocyanate A containing the oxadiazinone structure is shown as follows:

wherein M represents an alkyl substituent group having 6 to 12 carbons; wherein n is a statistical value, 0< n <4, and may be an integer or a non-integer.

2. The method according to claim 1, wherein M in the oxadiazinone structure represents a saturated aliphatic hydrocarbon or a saturated aliphatic cyclic hydrocarbon segment having 6 to 12 carbons.

3. The method according to claim 2, wherein M in the oxadiazinone structure is hexamethylene.

4. The preparation method according to claim 1, wherein the polyether polyol in the step (1) is obtained by ring-opening polymerization of propylene oxide and ethylene oxide using a small molecular polyol containing 2-6 hydroxyl groups as an initiator.

5. The method according to claim 4, wherein the polyether polyol of step (1) has a hydroxyl value of 10 to 80 mgKOH/g.

6. The method according to claim 5, wherein the polyether polyol in the step (1) has a hydroxyl value of 20 to 40 mgKOH/g.

7. The method according to claim 1, wherein the hydrazine in the step (1) is anhydrous hydrazine and/or hydrazine hydrate.

8. The method according to claim 7, wherein the hydrazine in the step (1) is hydrazine hydrate.

9. The method according to claim 1, wherein the diisocyanate in step (2) is a mixture of diisocyanate A and diisocyanate B.

10. The preparation method of claim 1, wherein the diisocyanate A in step (2) is obtained by reacting an isocyanate containing C6-C12 alkyl substituent group with carbon dioxide;

the diisocyanate A in the step (2) is obtained by reacting one or more of hexamethylene diisocyanate, cyclohexane methyl diisocyanate and tetramethyl butane diisocyanate with carbon dioxide.

11. The method according to claim 1, wherein the diisocyanate B in step (2) is an aliphatic isocyanate and/or an aromatic polyisocyanate.

12. The method according to claim 11, wherein the diisocyanate B in step (2) is one or more of m-phenylene diisocyanate, p-phenylene diisocyanate, polymethine polyphenyl polyisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, naphthalene diisocyanate, diphenylmethane-4, 4 '-diisocyanate, diphenylmethane-2, 2' -diisocyanate and hexamethylene diisocyanate.

13. The method according to claim 12, wherein the diisocyanate B in the step (2) is a mixture of 2, 4-toluene diisocyanate and 2, 6-toluene diisocyanate.

14. The preparation method according to claim 1, wherein the weight ratio of the diisocyanate to the polyether polyol in the step (2) is (0.05-0.45): 1;

the number of moles of NCO in the diisocyanate and NH of hydrazine₂The molar ratio of the radicals is (0.8-1.2): 1.

15. A carbon dioxide-releasable polyurea polyol made by the process of any one of claims 1-14.

16. A polyurethane foam prepared using the polyurea polyol prepared by the process of any one of claims 1-14 or the polyurea polyol of claim 15 as a starting material.