Multicomponent synergistic flame-retardant polymer polyols and methods for making the same

Abstract

The present application belongs to the technical field of polyurethane, and particularly relates to a multi-element synergistic flame-retardant polymer polyol and a preparation method thereof. The polyol is prepared by the reaction of a phosphorus-halogen mixed flame-retardant base polyether polyol, a halogen-containing flame-retardant vinyl unsaturated monomer and a silicon-containing flame-retardant vinyl unsaturated monomer, a nitrogen-containing modified polyether dispersant, styrene, acrylonitrile, an initiator and a chain transfer agent. The halogen-containing monomer introduced in the POP polymerization monomer directly participates in the free polymerization, and synergizes with the flame-retardant elements in the base polyether, so as to effectively increase the content of the flame-retardant elements in the POP and improve the flame retardancy. The vinyl silicon structure is added in the POP polymerization monomer, and the silicon element is introduced in the molecular chain, so that the hydrophobicity of the POP is improved in addition to the increased flame retardancy, and the viscosity of the combined material is reduced. The macromolecular nitrogen-containing dispersant is prepared by using a DMC catalytic process and polyurethane synthesis technology, so as to form a nitrogen-phosphorus-bromine ternary synergistic flame-retardant system, and further improve the flame retardancy of the POP.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyurethane, and particularly relates to a multi-element synergistic flame-retardant polymer polyol and a preparation method thereof. BACKGROUND

[0002] Polyurethane foam is widely used in daily life fields such as carpets, furniture and transportation. However, polyurethane foam is a flammable material, and flame-retardant polyurethane foam is a difficult problem in the industry. In addition to traditional additive flame retardants, flame-retardant polyethers have gradually formed various flame-retardant methods such as biomass flame-retardant, halogen flame-retardant and phosphorus flame-retardant through development. The biomass flame-retardant method, such as the method of using phosphorus-containing castor oil and straw liquefaction, has high cost and low yield, and is difficult to compete with traditional halogen flame-retardant; the halogen flame-retardant method, such as the method of using the product of hydrolysis of epichlorohydrin and halogen-containing aromatic diphenol in patent CN102633972A, has relatively complicated process steps; and the method of using hydrobromic acid as a halogen source in patent CN118005882A has a high risk factor for safe operation because concentrated sulfuric acid is used in the process. As an important component of soft polyurethane foam, polymer polyol (POP) is filled in the polyurethane network structure to effectively improve the open porosity, hardness and load bearing capacity of the polyurethane foam. In the flame-retardant of POP, flame-retardant vinyl monomers such as allyl methyl amino diphenyl phosphate and vinyl phosphonic acid are mainly used to introduce phosphorus elements or bromine-containing vinyl monomers such as 2,3-dibromostyrene into the polymer polyol.

[0003] The POP component contains a base polyether, a dispersant and a polymerized monomer, however, the current flame-retardant research on POP only focuses on the introduction of flame-retardant structures of polymerized monomers, and the flame-retardant properties of the base polyether, the dispersant and other components are not researched in detail, therefore, improving the flame-retardant properties of the base polyether, the dispersant and other raw materials in the POP and adopting a multi-element synergistic method become the key to improving the flame-retardant properties of the POP. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a multi-element synergistic flame-retardant polymer polyol, and the multi-element synergistic flame-retardant polymer polyol can improve the dispersibility and content of flame-retardant elements such as phosphorus, bromine and silicon in the POP.

[0005] The present application also provides a preparation method thereof, which is simple and easy to implement, and the prepared POP has excellent flame-retardant properties and hydrophobicity.

[0006] The multi-element synergistic flame-retardant polymer polyol is prepared from a phosphorus-halogen mixed flame-retardant base polyether polyol, a halogen-containing flame-retardant vinyl unsaturated monomer and a silicon-containing flame-retardant vinyl unsaturated monomer, a nitrogen-containing modified polyether dispersant, styrene, acrylonitrile, an initiator and a chain transfer agent.

[0007] The preparation method of the phosphorus-halogen mixed flame-retardant base polyether polyol is: taking trimethylol phosphine oxide (THPO) as a starting agent to react with an epoxy compound to obtain a phosphorus-containing polyether polyol, and then taking one or both of tetrachlorobisphenol A and tetrabromobisphenol A, the phosphorus-containing polyether polyol, and a polyether polyol as starting agents to react with an epoxy compound.

[0008] The halogen-containing flame-retardant vinyl unsaturated monomer is one or more of 2-chloroacrylonitrile, 2-bromostyrene, and 3-bromostyrene; and the silicon-containing flame-retardant vinyl unsaturated monomer is one of vinyl trimethoxysilane and vinyl (chloromethyl) dimethoxysilane.

[0009] The nitrogen-containing modified polyether dispersant is synthesized from a nitrogen-containing polyether and an unsaturated isocyanate.

[0010] The nitrogen-containing polyether has a functionality of 4-5.7, a number average molecular weight of 10,000-11,500 g / mol, and a nitrogen source of tris (2-hydroxyethyl) isocyanurate (THEIC).

[0011] Specifically, the method comprises the following three steps:

[0012] 1) selecting a high-functionality starting agent to react with an epoxy compound under the action of a catalyst to obtain a polyether polyol intermediate after refining;

[0013] 2) taking the polyether polyol intermediate and THEIC as a composite starting agent to react with an epoxy compound under the action of a catalyst to obtain a nitrogen-containing polyether with a functionality of 4-5.7;

[0014] 3) taking the nitrogen-containing polyether with a functionality of 4-5.7 to react with an unsaturated isocyanate under the action of a catalyst to perform a polymerization reaction for end-capping.

[0015] In step 1), the starting agent is one or both of solid sorbitol and liquid sorbitol, and the liquid sorbitol is preferred.

[0016] In step 1), the catalyst is one or more of alkali metal or phosphazene salt.

[0017] In step 1), the polyether polyol intermediate has a number average molecular weight of 900-2,000 g / mol, and preferably 1,500-1,800 g / mol.

[0018] In step 3), the unsaturated isocyanate is one or more of 3-isopropyl-dimethyl benzyl isocyanate, 2-methyl acrylate isocyanate ethyl ester, and isocyanate acrylate ethyl ester. The catalyst used is bismuth or zinc, and the reaction temperature is 70-90°C, and preferably 80°C.

[0019] The initiator is azo or peroxide, and the amount of initiator is 0.2-0.5% of the total mass of phosphorus-halogen mixed flame-retardant base polyether polyol, halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer.

[0020] The initiator is one of dimethyl azobis isobutyrate and tert-amyl peroxide-2-ethylhexanoate; the nitrogen-containing modified polyether dispersant is 1-11% of the total mass of phosphorus-halogen mixed flame-retardant base polyether polyol and olefinic unsaturated monomer.

[0021] The chain transfer agent is one or more of methanol, ethanol, butanol, isopropanol and mercaptan, preferably isopropanol; the amount of chain transfer agent is 3-10% of the total mass of phosphorus-halogen mixed flame-retardant base polyether polyol, halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer.

[0022] Preferably, the mass ratio of halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer is 5-10:1, and further preferably 10:1.

[0023] The preparation method of the polybasic synergistic flame-retardant polymer polyol comprises the following steps:

[0024] (1) using styrene, acrylonitrile and nitrogen-containing modified polyether dispersant to synthesize pre-reaction substance under the action of chain transfer agent and initiator;

[0025] (2) reacting the pre-reaction substance, phosphorus-halogen mixed flame-retardant base polyether polyol, halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer in the presence of initiator to obtain the polybasic synergistic flame-retardant polymer polyol.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] 1. The POP base polyether is synthesized into a structure type flame-retardant polyether polyol containing phosphorus-halogen flame-retardant elements by screening a reaction type flame-retardant initiator, and the synthesis method is simple, low in cost and convenient for industrialization; the halogen-containing monomer introduced in the POP polymerization monomer directly participates in free polymerization and synergizes with the flame-retardant elements in the base polyether, so that the content of flame-retardant elements in the POP is effectively increased, and the flame retardancy is improved.

[0028] 2. The vinyl silicon structure is increased in the POP polymerization monomer, and the silicon element is introduced in the molecular chain, so that the flame retardancy is increased and the hydrophobicity of the POP is improved, and the viscosity of the combined material is reduced by using the same, so that the downstream customers can use it conveniently.

[0029] 3, The macromolecular nitrogen-containing dispersant adopts DMC catalysis process and polyurethane synthesis technology, is green and environment-friendly, the synthesis method is simple and easy to implement, and the synthesis process can reduce "three wastes"; nitrogen elements are introduced into the macromolecular dispersant, a nitrogen-phosphorus-bromine ternary synergistic flame-retardant system is formed, and the flame retardance of the POP is further improved. DETAILED DESCRIPTION

[0030] The application will be further described below in combination with examples.

[0031] All raw materials used in the examples are commercially available, except for special instructions.

[0032] F5631, Shandong Yinaowei New Material Co., Ltd.;

[0033] C305, Shandong Yinaowei New Material Co., Ltd.;

[0034] Liquid sorbitol, VC grade, Shandong Tianli Pharmaceutical Co., Ltd.;

[0035] Tris (hydroxymethyl) phosphine oxide (THPO), Hubei Xingfa Group;

[0036] Tris (2-hydroxyethyl) isocyanurate (THEIC), Huawen Hongjiang Chemical Co., Ltd.;

[0037] Modified DMC, Jiangsu Bad Polyurethane Co., Ltd.;

[0038] Silicone oil, L580, Zhongshan Dongjun Chemical Co., Ltd.;

[0039] Toluene diisocyanate, T-80, Cangzhou Dahua Group Co., Ltd.

[0040] The phosphorus-halogen mixed flame-retardant base polyether polyol, the halogen-containing flame-retardant vinyl unsaturated monomer and the silicon-containing flame-retardant vinyl unsaturated monomer, the nitrogen-containing modified polyether dispersant, the initiator and the chain transfer agent are reacted to obtain.

[0041] Preparation Example 1: Preparation of phosphorus-halogen mixed flame-retardant base polyether polyol 1

[0042] 280 g of THPO and 7 g of KOH were added to a pressure-resistant reaction kettle, heated to 100 DEG C for 2 h of dehydration, 500 g of propylene oxide was slowly added, the internal pressure was 1 h after the completion of feeding, vacuum was used to remove monomers for 0.5 h, the temperature was lowered, 15 g of adsorbent magnesium aluminum silicate was added, and dehydration and drying were performed; the hydroxyl value of the obtained polyol of THPO polyether (phosphorus-containing polyether polyol) was 480.5 mgKOH / g;

[0043] Into a pressure reactor, 50 g of C305, 140 g of THPO polyether, 20 g of tetrachlorobisphenol A, 257 g of tetrabromobisphenol A and 0.3 g of modified DMC were added, and the temperature was raised to 130 °C for 2 h of dehydration. Then, 2540 g of a mixed liquid of propylene oxide and ethylene oxide was slowly added. After the completion of the addition, the internal pressure was maintained for 1 h, and then the monomer was removed under vacuum for 0.5 h. After cooling, the hydroxyl value of the obtained phosphorus-halogen mixed flame-retardant base polyether polyol 1 was tested to be 47.1 mgKOH / g.

[0044] Preparation Example 2: Preparation of phosphorus-halogen mixed flame-retardant base polyether polyol 2

[0045] Into a pressure reactor, 50 g of C305, 70 g of THPO polyether (Preparation Example 1), 30 g of tetrachlorobisphenol A, 380.8 g of tetrabromobisphenol A and 0.3 g of modified DMC were added, and the temperature was raised to 130 °C for 2 h of dehydration. Then, 2560 g of a mixed liquid of propylene oxide and ethylene oxide was slowly added. After the completion of the addition, the internal pressure was maintained for 1 h, and then the monomer was removed under vacuum for 0.5 h. After cooling, the hydroxyl value of the obtained base polyether polyol was tested to be 48.4 mgKOH / g.

[0046] Preparation Example 3: Preparation of nitrogen-containing modified polyether dispersant 1

[0047] Into a pressure reactor, 260 g of liquid sorbitol and 5 g of KOH were added, and the temperature was raised to 110 °C for 6 h of dehydration. Then, 1395 g of propylene oxide was slowly added. After the completion of the addition, the internal pressure was maintained for 1 h, and then the monomer was removed under vacuum for 0.5 h. After cooling, 22.8 g of phosphoric acid and 52.5 g of water were added for neutralization, and then 2 g of adsorbent magnesium aluminum silicate was added. After dehydration and drying, the hydroxyl value of the obtained polyether intermediate 1 polyol was tested to be 224.2 mgKOH / g.

[0048] Into a pressure reactor, 300 g of polyether polyol intermediate 1 and 210 g of THEIC were added, and the temperature was raised to 130 °C for 3 h. Then, 0.05 g of DMC catalyst was added, and the dehydration was continued for 1 h. Then, 30 g of propylene oxide was added dropwise to initiate the polymerization reaction, and then 7990 g of propylene oxide and 1500 g of ethylene oxide were added. After the completion of the addition, the internal pressure was maintained for 1 h, and then the monomer was removed under vacuum for 0.5 h. After cooling, the hydroxyl value of the obtained nitrogen-containing polyether 1 was tested to be 22.6 mgKOH / g, and the functionality was 4.

[0049] Into a pressure reactor, 1000 g of nitrogen-containing polyether 1 and 20.1 g of 3-isopropyl-dimethylbenzyl isocyanate were added, and 1 g of bismuth isooctoate was added. The temperature was raised to 80 °C, and the reaction was continued until the peak at 2261 cm-1 disappeared in the infrared spectrum, which was the reaction end point. -1

[0050] Preparation Example 4: Preparation of nitrogen-containing modified polyether dispersant 2

[0051] ​1350g of polyether polyol intermediate 1 and 26.2g of THEIC were added into a pressure-resistant reaction kettle, heated to 130℃, and timed for 3h. 0.05g of DMC catalyst was added, and the dehydration was continued for 1h. 30g of propylene oxide was added dropwise to initiate the polymerization reaction. Then, 7990g of propylene oxide and 1500g of a mixed liquid of ethylene oxide were added. After the completion of the feeding, the internal pressure was maintained for 1h, and the monomer removal was performed for 0.5h. The product was discharged. The nitrogen-containing polyether 2 had a hydroxyl value of 28.1 mgKOH / g and a functionality of 5.7.

[0052] The above 1150g of nitrogen-containing polyether 2, 78g of 2-methyl methacrylic acid isocyanate, and 71g of isocyanate acrylate were added into a reaction kettle, 1.2g of bismuth isooctoate was added, and the temperature was raised to 80℃. The reaction was terminated when the peak at 2261cm-1 disappeared in the infrared spectrum. -1

[0053] The preparation method of the multi-component synergistic flame-retardant polymer polyol comprises the following steps:

[0054] (1) Preparation of a pre-reaction product:

[0055] The nitrogen-containing modified polyether dispersant 1 and the nitrogen-containing modified polyether dispersant 2 prepared in the preparation examples, a mixture of isopropyl alcohol, styrene (SM), and acrylonitrile (AN), and dimethyl azobis isobutyrate were added into a batching tank. The mixture was transported from a feeding tank to a static mixer by a laminar flow pump, and then sequentially entered two reactors connected in series to perform polymerization. The mixed reaction temperature of the two reactors was 110±5℃, and the residence time in the two reactors was 60 minutes, respectively. The pre-reaction product from the second reactor was cooled by a cooler, and then collected for standby. The mass percentage content of PA (prepared from the nitrogen-containing modified polyether dispersant 1) or PB (prepared from the nitrogen-containing modified polyether dispersant 2), isopropyl alcohol, styrene (SM), acrylonitrile (AN), and initiator was 24%, 59.8%, 8%, 8%, and 0.2%, respectively.

[0056] (2) Preparation of a polymer polyol:

[0057] ​The mixture of pre-reactants PA, PB, phosphorus halogen mixed flame-retardant base polyether polyol, 2-bromostyrene, 2-chloropropenyl cyanide, vinyl trimethoxysilane and tert-amyl peroxide-2-ethylhexanoate, and F5631, styrene, acrylonitrile used in the comparative example were added into the charging tank, the materials were transported from the feeding tank to the static mixer by the laminar pump, and then sequentially entered into the first and second reaction kettles through the feeding pipe to make the components fully mixed and reacted, wherein the reaction temperature of the two reaction kettles was 125±2℃, and the residence time in the two reaction kettles was 60 minutes respectively, and the crude product from the second stage reaction kettle was introduced into the single removal kettle, and vacuum was applied to remove unreacted volatile substances. The mass content of raw materials of examples 1-4 and comparative examples 1-4 is shown in Table 1, wherein the amount of initiator is calculated based on the total mass of raw materials, and the product performance test results of examples 1-4 and comparative examples 1-4 are shown in Table 2.

[0058] Table 1 Mass content of raw materials of examples 1-4 and comparative examples 1-4

[0059]

[0060] Table 2 Product performance test table of examples 1-4 and comparative examples 1-4

[0061]

[0062] The POP prepared in the examples and comparative examples was compounded according to the formulation in Table 3 below, and the foam limiting oxygen index test data is shown in Table 4:

[0063] Table 3 POP compounding formulation table

[0064]

[0065] Table 4 Foam limiting oxygen index test data table

[0066]

[0067] It is found by comparison that, compared with the traditional POP of comparative example 4, the POP prepared by introducing flame-retardant elements can significantly improve the flame-retardant effect of the foam sponge; it is found by comparing the examples with comparative examples 1-3 that the multi-element synergy of the flame-retardant elements is more conducive to improving the flame-retardant effect.

Claims

1. A multi-element synergistic flame-retardant polymer polyol, characterized in that, The phosphorus-halogen mixed flame-retardant base polyether polyol, halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer, nitrogen-containing modified polyether dispersant, styrene, acrylonitrile, initiator, chain transfer agent are reacted to obtain the product; The preparation method of the phosphorus-halogen mixed flame-retardant base polyether polyol is as follows: a phosphorus-containing polyether polyol is prepared by reacting trimethylol phosphine oxide with an epoxy compound, and then one or both of tetrachlorobisphenol A and tetrabromobisphenol A, the phosphorus-containing polyether polyol and polyether polyol are used as starting agents to react with an epoxy compound to obtain the product. The nitrogen-containing modified polyether dispersant is synthesized by the nitrogen-containing polyether and unsaturated isocyanate. The nitrogen-containing polyether has a functionality of 4-5.7, a number average molecular weight of 10000-11500 g / mol, and a nitrogen source of tris(2-hydroxyethyl) isocyanurate.

2. The multi-site synergistic flame retardant polymer polyol of claim 1, wherein, The halogen-containing flame-retardant vinyl unsaturated monomer is one or more of 2-chloropropylene nitrile, 2-bromostyrene and 3-bromostyrene; and the silicon-containing flame-retardant vinyl unsaturated monomer is one of vinyl trimethoxysilane and vinyl(chloromethyl)dimethoxysilane.

3. The multi-site synergistic flame retardant polymer polyol of claim 1, wherein, The unsaturated isocyanate is one or more of 3-isopropyl-dimethylbenzyl isocyanate, 2-methyl acrylate isocyanate ethyl and isocyanate acrylate ethyl.

4. The multi-site synergistic flame retardant polymer polyol of claim 1, wherein, The initiator is one of dimethyl azobis-2-ethylhexanoate or tert-amyl peroxide-2-ethylhexanoate.

5. The multi-site synergistic flame retardant polymer polyol of claim 4, wherein, The mass ratio of the halogen-containing flame-retardant vinyl unsaturated monomer to the silicon-containing flame-retardant vinyl unsaturated monomer is 5-10:

1.

6. The multi-site synergistic flame retardant polymer polyol of claim 1, wherein, The chain transfer agent is isopropyl alcohol.

7. A method for preparing a multi-component synergistic flame-retardant polymer polyol according to any one of claims 1-6, characterized in that, The method comprises the following steps: (1) using styrene, acrylonitrile and nitrogen-containing modified polyether dispersant to synthesize a pre-reaction product under the action of chain transfer agent and initiator; (2) reacting the pre-reaction product, phosphorus-halogen mixed flame-retardant base polyether polyol, halogen-containing flame-retardant vinyl unsaturated monomer and silicon-containing flame-retardant vinyl unsaturated monomer in the presence of initiator to obtain the product.

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