A nitrogen-containing heterocyclic aromatic polyether polyol, a method for preparing the same, and a polyurethane rigid foam

Abstract

The application discloses a nitrogen-containing heterocyclic aromatic polyether polyol, a preparation method thereof and a polyurethane rigid foam. The structural formula of the nitrogen-containing heterocyclic aromatic polyether polyol is shown as follows: the use of the nitrogen-containing heterocyclic aromatic polyether polyol enables the prepared rigid polyurethane foam to have high strength, better dimensional stability and lower thermal conductivity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polyurethane rigid foam material, and particularly relates to a nitrogen-containing heterocyclic aromatic polyether polyol and application thereof in polyurethane rigid foam. BACKGROUND

[0002] As a kind of polymer thermal insulation material, rigid polyurethane foam has a wide application in the field of thermal insulation due to its high strength, heat insulation and other excellent properties. However, with the increasing scarcity of global resources, society has increasingly high requirements for resource-saving products, and the construction of zero-carbon parks and zero-carbon communities has become a development direction in the future. Therefore, high-strength and good thermal-conductive polyurethane foam is one of the important directions of current research.

[0003] CN106590379A discloses that a bromine-containing diol / phenol is used as a starting agent to perform ring-opening polymerization reaction with epichlorohydrin under the action of a catalyst to obtain a polyepoxy chloropropane with double functionality, then the above product is reacted with a strong alkali solution to obtain an epoxy-terminated compound, and finally the epoxy-terminated compound is subjected to hydrolysis reaction and then post-treatment to obtain a halogen-containing flame-retardant polyether polyol. The process has the advantages of cheap and readily available raw materials and simple reaction; however, the polyether polyol prepared by the method has low activity compared with aniline polyether, and the strength and thermal conductivity of the prepared foam are not improved well.

[0004] CN104877105A discloses a polyurethane rigid foam combination material and a preparation method thereof, which uses HFC-365mfc / 227ea as a foaming agent, has high cost and is not environmentally friendly.

[0005] CN101257947A discloses a catalyst system for formic acid foaming of polyisocyanurate rigid foam, a method for producing the polyisocyanurate rigid foam, and a polyisocyanurate rigid foam obtainable by the method. The prepared combination material cannot be applied to a pipeline spraying system, and contains a physical foaming agent pentane, which is flammable and explosive.

[0006] Therefore, in view of the above problems, it is desirable to synthesize a simple and efficient reactive polyol to solve the problems of non-environmental protection and non-safety of the above combination material, and to improve the strength and reduce the thermal conductivity of the polyurethane foam. SUMMARY

[0007] The present application aims to provide a nitrogen-containing heterocyclic aromatic polyether polyol, a preparation method thereof and a polyurethane rigid foam. The nitrogen-containing heterocyclic aromatic polyether polyol is synthesized by epoxidation using a nitrogen-containing heterocyclic compound as a starting agent. The polyether polyol can improve the physical structure of foam cells, so that the foam has good physical strength, good dimensional stability and low thermal conductivity.

[0008] The technical scheme adopted by the present application is as follows:

[0009] In one aspect, the present application provides a nitrogen-containing heterocyclic aromatic polyether polyol, whose structural formula is shown as follows:

[0010]

[0011] wherein n is any integer from 2 to 6, preferably from 2 to 5.

[0012] The nitrogen-containing heterocyclic aromatic polyether polyol has an average hydroxyl value of preferably 120-315 mgKOH / g, more preferably 130-240 mgKOH / g, and a functionality of 1.

[0013] In another aspect, the present application provides a method for preparing the nitrogen-containing heterocyclic aromatic polyether polyol as described above.

[0014] The method for preparing the nitrogen-containing heterocyclic aromatic polyether polyol comprises the following steps: etherification of a nitrogen-containing heterocyclic aromatic compound and an alkylene oxide; the nitrogen-containing heterocyclic aromatic compound is a purine.

[0015] As a preferred solution, in the method of the present application, the alkylene oxide is propylene oxide.

[0016] As a preferred solution, in the method of the present application, the reaction is carried out in the presence of an inert gas.

[0017] As a preferred solution, in the method of the present application, the reaction is carried out under a pressure of 0.2-0.3 MPa (relative pressure).

[0018] As a preferred solution, in the method of the present application, the reaction temperature is 80-160°C, preferably 100-130°C.

[0019] As a preferred solution, in the method of the present application, after the reaction, a crude treatment is carried out, which comprises the following steps: adding an adsorbent to the product, filtering at a certain temperature, and collecting the filtrate to obtain a crude polyether polyol.

[0020] As a preferred solution, in the method of the present application, after the crude treatment, a refining is carried out, which comprises the following steps: removing water and other by-products from the crude polyether polyol at a certain temperature and under high vacuum to obtain the product.

[0021] In still another aspect, the present application provides the use of the nitrogen-containing heterocyclic aromatic polyether polyol as described above in the preparation of a polyurethane rigid foam.

[0022] The polyurethane rigid foam comprises the following components by mass fraction:

[0023]

[0024] The polyether polyol composition of the present invention comprises the following components: by weight parts,

[0025]

[0026] The sorbitol polyether polyol described in this invention is obtained by ring-opening polymerization of propylene oxide with sorbitol as the initiator, and has a hydroxyl value of 450-500 mgKOH / g.

[0027] The sucrose polyether polyol described in this invention is obtained by ring-opening polymerization of propylene oxide with sucrose as the initiator, and has a hydroxyl value of 360-500 mgKOH / g.

[0028] The propylene glycol polyether polyol described in this invention is obtained by ring-opening polymerization of propylene oxide with propylene glycol as the initiator, and has a hydroxyl value of 100-150 mg KOH / g.

[0029] The surfactant described in this invention is a siloxane surfactant, preferably selected from any one or more combinations of B84806, AK8805, Dongjun H3636, DC193, M88108, B8423, B84806, Y16368, B8404, and AK8812, with B84806 being the most preferred.

[0030] The viscosity reducer of the present invention is selected from any one or more combinations of propylene esters, alkyl ketone organic compounds, tris(2-chloropropyl) phosphate, triethyl phosphate, organosilicon oligomers, phthalates, aliphatic diesters, isobutyrates, polyphenolic esters, epoxy hydrocarbons, and alkyl sulfonates; preferably one or more of propylene esters, alkyl ketone organic compounds, tris(2-chloropropyl) phosphate, and triethyl phosphate; more preferably propylene carbonate and / or triethyl phosphate.

[0031] The catalysts described in this invention mainly include amine catalysts and / or organometallic salt catalysts; the amine catalysts are any one or more combinations of bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, triethylenediamine, triethylamine, 1,4-dimethylpiperazine, N,N-dimethylbenzylamine, and bis(2-dimethylaminoethyl) ether, preferably one or more combinations of bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, and triethylenediamine; the organometallic salt catalysts are any one or more combinations of potassium acetate, stannous octoate, potassium isooctanoate, and dibutyltin dilaurate, preferably one or more combinations of dibutyltin dilaurate, potassium isooctanoate, and potassium acetate.

[0032] The foaming agent described in this invention is preferably HFC-245fa foaming agent.

[0033] The isocyanate described in this invention is polymeric MDI (polymethylene polyphenyl polyisocyanate) with an NCO content of 30-32%, preferably Wanhua Chemical's PM-200.

[0034] The composite material of the present invention can be prepared using conventional methods when preparing polyurethane foam. In one embodiment, the components of the composite material are added to a material tank in proportion, and then sprayed onto a rotating and uniformly advancing steel pipe by a high-pressure machine or spraying machine for automatic curing and molding to obtain polyurethane foam; preferably, the mixing and foaming conditions are: material temperature 45-50℃, gauge pressure 700-850psi.

[0035] This invention has the following advantages:

[0036] The rigid polyurethane foam prepared by this invention has high strength, good dimensional stability and low thermal conductivity.

[0037] The foaming agent described in this invention is HFC-245fa, which is a third-generation alternative foaming agent with an ozone depletion potential (ODP) of 0 and no destructive effect on the ozone layer.

[0038] The foam produced by this invention achieves good performance even with a low density, with the finished product density reaching 60-78 kg / m³. 3 Water absorption rate ≤8%, closed cell rate ≥90%, thermal conductivity at 50℃ ≤0.033W / (mK), radial compressive strength ≥0.3Mpa. Detailed Implementation

[0039] The embodiments of the present invention are further illustrated below. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0040] The raw materials used in the examples and comparative examples are as follows:

[0041] Polyether polyol B: Sorbitol as initiator, propylene oxide as polymerizing monomer, hydroxyl value 470mgKOH / g, functionality 5.2, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0042] Polyether polyol C: sucrose as the initiator, propylene oxide as the polymerization monomer, hydroxyl value of 410 mgKOH / g, functionality of 4.3, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0043] Polyether polyol D: Propylene glycol as initiator, propylene oxide as polymerizing monomer, hydroxyl value 110mgKOH / g, functionality 2.0, Wanhua Chemical (Yantai) Rongwei Polyurethane Co., Ltd.

[0044] Viscosity reducer: propylene carbonate, abbreviated as PC, purchased from Shanghai Titan Technology Co., Ltd.;

[0045] Surfactant: B84806, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.;

[0046] Amine catalysts: bis(dimethylaminoethyl) ether, pentamethyldiethylenetriamine, and triethylenediamine were purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0047] Organometallic salt catalysts: dibutyltin dilaurate, potassium isooctanoate, potassium acetate, Xindian Chemical Materials (Shanghai) Co., Ltd.;

[0048] Foaming agent: HFC-245fa, purchased from Honeywell;

[0049] Isocyanate: PM200, Wanhua Chemical Group Co., Ltd.

[0050] Preparation of polyether polyol A:

[0051] 1) Add 500g of purine (molecular formula C5H4N4) and 5g of KOH to the reaction vessel, fully purify with nitrogen, and stir;

[0052] 2) Raise the reaction temperature to 100°C, slowly add 500g of propylene oxide, and react at 100°C until the propylene oxide is added. Then raise the temperature to 110°C and mature for another hour.

[0053] 3) Heat to 120°C, add the remaining 500g of propylene oxide, and maintain the pressure of the reactor at 0.2-0.3 MPa until the remaining propylene oxide is added; then heat to 120-125°C and continue to mature for 2-3 hours.

[0054] 4) 7.5g of phosphoric acid was added to the reaction product to remove potassium ions from the solution, and molecular sieves were added for adsorption. After vacuum filtration, crude polyether polyol was obtained.

[0055] 5) The crude polyether polyol was heated to 115℃ and vacuum removed to remove unreacted propylene oxide and other byproducts, yielding the final product. The hydroxyl value was 237 mg KOH / g.

[0056] Preparation of polyether polyol a:

[0057] 1) Add 500g of purine and 5g of KOH to the reaction vessel, fully purify with nitrogen, and stir;

[0058] 2) Raise the reaction temperature to 100°C, slowly add 3000g of propylene oxide, and react at 100°C until the propylene oxide is added. Then raise the temperature to 110°C and mature for another hour.

[0059] 3) Heat to 120℃, add the remaining 3050g of propylene oxide, maintain the pressure of the reactor at 0.2~0.3Mpa until the remaining propylene oxide is added; then heat to 120~125℃ and continue to mature for 2~3 hours.

[0060] 4) 7.5g of phosphoric acid was added to the reaction product to remove potassium ions from the solution, and molecular sieves were added for adsorption. After vacuum filtration, crude polyether polyol was obtained.

[0061] 5) The crude polyether polyol was heated to 115℃ and vacuum removed to remove unreacted propylene oxide and other byproducts, yielding the final product. The hydroxyl value was 136 mg KOH / g.

[0062] Preparation of polyether polyol A1:

[0063] 1) Add 500g of purine and 5g of KOH to the reaction vessel, fully purify with nitrogen, and stir;

[0064] 2) Raise the reaction temperature to 100°C, slowly add 121g of propylene oxide, and react at 100°C until the propylene oxide is added. Then raise the temperature to 110°C and mature for another hour.

[0065] 3) Heat to 120°C, add the remaining 120g of propylene oxide, and maintain the pressure of the reactor at 0.2-0.3 MPa until the remaining propylene oxide is added; then heat to 120-125°C and continue to mature for 2-3 hours.

[0066] 4) 7.5g of phosphoric acid was added to the reaction product to remove potassium ions from the solution, and molecular sieves were added for adsorption. After vacuum filtration, crude polyether polyol was obtained.

[0067] 5) The crude polyether polyol was heated to 115℃ and vacuum removed to remove unreacted propylene oxide and other byproducts, yielding the final product. The hydroxyl value was 315 mg KOH / g.

[0068] The n of polyether polyol A is approximately 2, the n of polyether polyol a is approximately 5, and the n of polyether polyol A1 is approximately 1.

[0069] Preparation of rigid polyurethane foam:

[0070] According to the different proportions of the comparative examples and embodiments in Table 1, the polyether polyol composition, viscosity reducer, surfactant, catalyst and water are mixed evenly, and then the foaming agent is added and mixed evenly to obtain the corresponding white material. The prepared white material and black material (isocyanate) are added to the material tank in proportion and sprayed onto the rotating and uniformly moving steel pipe by the spraying machine to automatically cure and form polyurethane foam; wherein, the mixing and foaming conditions are: material temperature 45-50℃, gauge pressure 700-850psi.

[0071] The foam properties are shown in Table 2.

[0072] Table 1. Raw materials and parts by weight for Examples 1-5 and Comparative Examples 1-2

[0073]

[0074]

[0075] Table 2 Foam performance of Examples 1-5 and Comparative Examples 1-2

[0076]

[0077] As shown in Tables 1 and 2, the combinations in Examples 1-5 can all produce polyurethane foam that meets the technical specifications. However, the polyurethane foam produced from the combinations in Comparative Examples 1-2 does not meet the technical specifications.

Claims

1. A nitrogen-containing heterocyclic aromatic polyether polyol, with the following structural formula: in, n is any integer from 2 to 6.

2. The nitrogen-containing heterocyclic aromatic polyether polyol according to claim 1, wherein, n is any integer from 2 to 5.

3. A rigid polyurethane foam, comprising the following components: by weight parts, 70-90 parts of polyether polyol composition; 1-3 parts surfactant; Viscosity reducer 3-6 parts; 3-6 parts catalyst; 1-2 parts water; 6-9 parts of foaming agent; 135-160 parts of isocyanate; The polyether polyol composition comprises the nitrogen-containing heterocyclic aromatic polyether polyol as described in claim 1 or 2.

4. The rigid polyurethane foam according to claim 3, characterized in that, The polyether polyol composition comprises the following components: According to weight parts, 1-25 parts of nitrogen-containing heterocyclic aromatic polyether polyol; 30-55 parts of sorbitol polyether polyol; 5-20 parts of sucrose polyether polyol; 2-10 parts of propylene glycol polyether polyol.

5. The rigid polyurethane foam according to claim 4, characterized in that, The polyether polyol composition comprises the following components: According to weight parts, 7-20 parts of nitrogen-containing heterocyclic aromatic polyether polyol; 40-50 parts of sorbitol polyether polyol; 10-15 parts of sucrose polyether polyol; 5-9 parts of propylene glycol polyether polyol.

6. The rigid polyurethane foam according to claim 4 or 5, characterized in that, The sorbitol polyether polyol is obtained by ring-opening polymerization of propylene oxide with sorbitol as the initiator, and has a hydroxyl value of 450-500 mg KOH / g.

7. The rigid polyurethane foam according to claim 4 or 5, characterized in that, The sucrose polyether polyol is obtained by ring-opening polymerization of propylene oxide with sucrose as the starting agent, and has a hydroxyl value of 360-500 mgKOH / g.

8. The rigid polyurethane foam according to claim 4 or 5, characterized in that, The propylene glycol polyether polyol is obtained by ring-opening polymerization of propylene oxide with propylene glycol as the initiator, and has a hydroxyl value of 100-150 mg KOH / g.

9. The rigid polyurethane foam according to any one of claims 3-5, characterized in that, The surfactant is a siloxane surfactant; and / or The viscosity reducer is selected from any one or more combinations of propylene carbonate, tri(2-chloropropyl) phosphate, triethyl phosphate, organosilicon oligomers, phthalates, aliphatic diesters, isobutyrates, polyphenolic esters, epoxy hydrocarbons, and alkyl sulfonates.

10. The rigid polyurethane foam according to claim 9, characterized in that, The surfactant is selected from any one or a combination of B84806, AK8805, Dongjun H3636, DC193, M88108, B8423, Y16368, B8404, and AK8812.

11. The rigid polyurethane foam according to any one of claims 3-5, characterized in that, The catalyst includes at least one of amine catalysts and / or organometallic salt catalysts; The amine catalyst is any one or a combination of pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, triethylenediamine, triethylamine, 1,4-dimethylpiperazine, N,N-dimethylbenzylamine, and bis(2-dimethylaminoethyl) ether; the organometallic salt catalyst is any one or a combination of potassium acetate, stannous octoate, potassium isooctanoate, and dibutyltin dilaurate.

12. The rigid polyurethane foam according to any one of claims 3-5, characterized in that, The foaming agent mentioned is HFC-245fa foaming agent.

13. The rigid polyurethane foam according to any one of claims 3-5, characterized in that, The isocyanate mentioned is polymeric MDI.

14. The rigid polyurethane foam according to claim 13, characterized in that, The isocyanate NCO content is 30-32%.

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