Isocyanate prepolymer composition capable of being stably stored and preparation method thereof

Abstract

The invention provides an isocyanate prepolymer composition capable of being stably stored and a preparation method thereof. The composition contains an isocyanate prepolymer and a phosphazene compound. The phosphazene compound does not react with isocyanate substances in a system, an alkaline or metal catalyst can be captured in a prepolymer compound system to inactivate the prepolymer compound system, further reaction crosslinking of isocyanate and carbamate / allophanate is reduced, generation of macromolecular polymers is reduced, and the service life of the polyurethane is prolonged. The product viscosity and composition change are reduced; and the storage stability of the product is improved.

Description

Technical Field

[0001] The invention belongs to the field of isocyanates, and in particular relates to a composition of an isocyanate prepolymer capable of being stably stored and a preparation method thereof. Background Art

[0002] Isocyanate is the raw material of polyurethane, which is mainly prepared by phosgenation of corresponding amines. Organic amine reacts with phosgene to obtain isocyanate, which is divided into aromatic isocyanate and aliphatic isocyanate according to different chemical structures. They can react with different polyols to obtain polyurethane materials with different properties, including foams, elastomers, etc. Due to the high activity of isocyanate groups, they can react with primary amine / hydroxyl, secondary amine compounds, etc. under heating and alkali catalysis. Whether it is one or more of the isocyanate prepolymers obtained by reacting aromatic isocyanate, aliphatic isocyanate, carbodiimide-modified isocyanate or carbamate-modified isocyanate with polyols having active hydrogen, under heating and catalysis of alkaline catalysts or metal catalysts, isocyanate reacts with the secondary amine groups in carbamate to generate macromolecular cross-linked compounds, resulting in the loss of NCO (isocyanate group) of the product, and the viscosity of the liquid product increases, resulting in product deterioration, and in severe cases, the product solidifies. In the isocyanate prepolymer obtained by the reaction of isocyanate and polyol with active hydrogen, the product viscosity and NCO are often abnormal, or even solidified, due to the high reaction activity during the production process. During storage and transportation, the product viscosity increases and the NCO decreases. The instability of isocyanate-based prepolymers is mainly caused by the catalyst residues in the polyol with active hydrogen, and it is more likely to occur in scenes with high ambient temperatures. Once the catalyst content exceeds the standard, isocyanate reacts with carbamate to form cross-linked macromolecules, causing product deterioration and resulting in economic losses.

[0003] In summary, there is an urgent need in the art to improve the storage stability of isocyanate prepolymers and reduce the risk of deterioration during production, storage and transportation. Summary of the invention

[0004] One of the purposes of the present invention is to provide a method for improving the storage stability of isocyanate prepolymers, which can improve the storage stability of isocyanate prepolymers and reduce the risk of deterioration during production, storage and transportation.

[0005] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0006] An isocyanate prepolymer composition, the composition contains an isocyanate prepolymer and a phosphazene compound; wherein the weight ratio of the phosphazene compound to the isocyanate compound is (0.001-1.0):100, preferably (0.003-0.01):100.

[0007] The catalyst in the polyether polyol in the art is mainly a basic catalyst, such as KOH, etc., and the catalyst in the polyester polyol is mainly a metal catalyst, such as tetrabutyl titanate, etc. If the catalyst residue is above 1ppm during the polyol production process, the residual catalyst accelerates the reaction between the polyol and the isocyanate, and catalyzes the reaction between the isocyanate and the carbamate to form a cross-linked macromolecular substance, causing the product to deteriorate. The inventor has found that phosphazene substances are Lewis acids with strong acidity due to their central electron-deficient structure, and are very easy to capture alkaline substances. When added to isocyanate, they can be combined with the catalyst in the prepolymerization reaction to make it lose its catalytic activity, thereby reducing the catalyst concentration to achieve the purpose of reducing the reaction activity and extending the shelf life.

[0008] In one embodiment of the present invention, the isocyanate prepolymer is a prepolymer obtained by the reaction of isocyanate and an active hydrogen-containing polyol; preferably, the isocyanate is one or more of an aliphatic isocyanate, an alicyclic isocyanate, an aromatic isocyanate, and a compound containing the above isocyanate structure, preferably one or more of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, urethane-modified isocyanate, and carbodiimide-modified isocyanate; preferably, the active hydrogen-containing polyol is one or more of a 2-3-valent polyether or polyester polyol with a molecular weight of 100-3000, preferably one or more of C2020, PBA2000, C1010, and PTMG2000.

[0009] In one embodiment of the present invention, the structure of the phosphazene compound is as follows:

[0010]

[0011] Wherein, R is C1-C18 alkoxy and / or chlorine, preferably one or more of C1-C3 alkoxy.

[0012] In one embodiment of the present invention, the phosphazene compound comprises hexachlorophosphazene and / or a phosphazene compound obtained by a substitution reaction between hexachlorophosphazene and sodium primary alcohol of C1-C18.

[0013] Another object of the present invention is to provide a method for preparing the isocyanate prepolymer composition.

[0014] A method for preparing an isocyanate prepolymer composition, wherein the composition is the above-mentioned isocyanate prepolymer composition, and the preparation method comprises adding a phosphazene compound during the isocyanate prepolymerization process.

[0015] Another object of the present invention is to provide a method for preparing the phosphazene compound.

[0016] A method for preparing a phosphazene compound, wherein the compound is the above-mentioned phosphazene compound, and the method comprises the following steps:

[0017] The sodium primary alcohol of C1-C18 is reacted with hexachlorophosphazene in a solvent, washed with water to obtain a crude product, and recrystallized to obtain the phosphazene compound.

[0018] In one embodiment of the present invention, the molar ratio of sodium primary alcohol to hexachlorophosphazene in the method is (6.0-6.6):1.

[0019] Another object of the present invention is to provide a use of the isocyanate prepolymer composition.

[0020] The invention discloses a use of an isocyanate prepolymer composition, wherein the composition is the above-mentioned isocyanate prepolymer composition, or is a composition prepared by the above-mentioned preparation method, and the composition is used as an isocyanate prepolymer with high storage stability, preferably as a raw material prepolymer for producing polyurethane adhesives, coatings, and soft foams.

[0021] Compared with the prior art, the positive effects of the present invention are:

[0022] The addition of phosphazene compounds to isocyanate reduces the reactivity of the isocyanate compound, adapts to polyols with different reactivity, makes the reaction process controllable, and makes the storage performance of the prepolymer obtained by the reaction more stable. The shelf life of the prepolymer prepared with high-activity polyol is extended by more than six times. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the embodiments.

[0024] The raw materials are from the following sources, industrial grade:

[0025] MDI-50 Wanhua Chemical Group Co., Ltd.

[0026] MDI-100 Wanhua Chemical Group Co., Ltd.

[0027] HDI Wanhua Chemical Group Co., Ltd.

[0028] Polyether polyol C2020 Wanhua Chemical Group Co., Ltd.

[0029] Polyester polyol PBA2000 Wanhua Chemical Group Co., Ltd.

[0030] TDI-80 Wanhua Chemical Group Co., Ltd.

[0031] Hexachlorophosphazene Beijing Inokai Technology Co., Ltd.

[0032] Instruments and equipment:

[0033] Potentiometric titrator, METTLER TOLEOO, model: 905Titrando;

[0034] Viscometer, BROOKFIELD, model: DV2TLVTJO;

[0035] Nuclear magnetic resonance spectrometer, Bruker, Germany, model: Bruker AvanceⅢ500 / 400MHz;

[0036] High-resolution direct-injection time-of-flight mass spectrometer, Micromass, UK, model: GCT.

[0037] Preparation Example 1

[0038] Dissolve 10g of KOH in 20g of water to prepare a KOH aqueous solution with a mass fraction of 33.3%. Take 0.025g of the above KOH aqueous solution and add it to 1000g of C2020 to prepare a high-activity C2020 with a K ion concentration of 5ppm.

[0039] Preparation Example 2

[0040] Dissolve 20g of tetrabutyl titanate in 20g of propylene glycol to prepare a 50% by mass tetrabutyl titanate propylene glycol solution. Take 0.07g of the above tetrabutyl titanate propylene glycol solution and add it to 1000g of PBA2000 to prepare a high-activity PBA2000 with a titanium ion concentration of 5ppm.

[0041] Preparation Example 3

[0042] Dissolve sodium octadecyl alcoholate in acetone, place in a reactor, heat to 55°C and reflux, then drop hexachlorophosphazene acetone solution into the reactor, wherein the molar ratio of hexachlorophosphazene to sodium alcoholate is 1:6.5. Reflux for 48 hours, remove the solvent after the reaction, wash with water to obtain a crude product. Heat the crude product with ethanol to reflux, stir for 2 hours, cool to room temperature, and filter to obtain the product.

[0043] Preparation Example 4

[0044] Sodium ethoxide was dissolved in acetone, placed in a reactor, heated to 55°C and refluxed, and then the acetone solution of hexachlorophosphazene was added dropwise to the reactor, wherein the molar ratio of hexachlorophosphazene to sodium ethoxide was 1:6.5. The reaction was refluxed for 30 hours, and after the reaction, the solvent was removed and washed with water to obtain a crude product. The crude product was heated to reflux with ethanol, stirred for 2 hours, cooled to room temperature, and filtered to obtain the product.

[0045] The hexa(ethoxy)cyclophosphazene prepared in this preparation example was characterized, and the result data are as follows:. 1H NMR(400MHz, DMSO)δ4.01(p,J=8.6Hz,12H),1.2(t,J=7.3Hz,18H).TOF-EI-MS(m / z):calcd.forC 12 H 30 N3O6P3 405.1335,found 405.1308[M + ].

[0046] Example 1

[0047] Take 1 g of hexa(octadecyloxy)cyclophosphazene in Preparation Example 2 and add it to 1000 g of MDI-100. After stirring evenly, take 449 g and put it in a four-necked flask. Keep the temperature in an oil bath at 55°C. When the material temperature reaches 50°C, add 835 g of the highly reactive C2020 obtained in Preparation Example 1 into the flask. Start mechanical stirring, and raise the material temperature to 80°C through an oil bath. React at this temperature for 3 hours. The product is a prepolymer with an NCO content of 9.01%.

[0048] Use a 100mL glass bottle to weigh 100g of prepolymer and store it in a constant temperature and humidity chamber at a temperature of 35°C and a humidity of 40% for sample shelf life test. Test the sample viscosity and NCO after 30 days and 100 days to obtain the sample shelf life data. The viscosity test method refers to GB / T 10247-2008, and the NCO test method refers to GB / T 9725-2007.

[0049] Example 2

[0050] Take 0.05g of hexa(ethoxy)cyclic phosphazene in Preparation Example 2 and add it to 1000g of MDI-100. After stirring evenly, take 449g and put it in a four-necked bottle. Keep the temperature in a 55°C oil bath. When the material temperature reaches 50°C, add 835g of the highly reactive C2020 obtained in Preparation Example 1 into the flask, start mechanical stirring, and raise the material temperature to 80°C through an oil bath. React at this temperature for 3 hours. The product is a prepolymer with an NCO content of 9.01%.

[0051] Use a 100mL glass bottle to weigh 100g of prepolymer and store it in a constant temperature and humidity chamber at 35°C and 40% humidity for sample shelf life test. Test the sample viscosity and NCO after 30 days and 100 days to obtain the sample shelf life data.

[0052] Example 3

[0053] Take 0.05g of hexachlorophosphazene and add it to 1000g of TDI-80. After stirring evenly, take 125g and place it in a four-necked bottle. Keep the temperature in a 55℃ oil bath. When the material temperature reaches 50℃, add 537g of the highly reactive C2020 obtained in Preparation Example 1 to the flask, start mechanical stirring, and raise the material temperature to 80℃ through an oil bath. React at this temperature for 3 hours. The product is a prepolymer with an NCO content of 9.03%. Use a 100mL glass bottle to weigh 100g of the prepolymer, store it in a constant temperature and humidity chamber, and test the sample shelf life at a temperature of 35℃ and a humidity of 40%. Observe the appearance of the sample after 30 days and 100 days, test the sample viscosity and NCO, and obtain the sample shelf life data.

[0054] Example 4

[0055] 0.05g of hexa(ethoxy)phosphazene was added to 1000g of HDI, and after stirring, 125g was taken and placed in a four-necked flask, and the temperature was kept constant at 55°C in an oil bath. When the material temperature reached 50°C, 561g of the highly reactive C2020 obtained in Preparation Example 1 was added to the flask, mechanical stirring was started, and the material temperature was raised to 80°C by an oil bath, and the reaction was carried out at this temperature for 3 hours. The product was a prepolymer with an NCO content of 9.03%. 100g of the prepolymer was weighed in a 100mL glass bottle, and stored in a constant temperature and humidity chamber at a temperature of 35°C and a humidity of 40% for sample shelf life testing. The sample appearance was observed after 30 days and 100 days, and the sample viscosity and NCO were tested to obtain the sample shelf life data.

[0056] Example 5

[0057] 0.05g of hexa(ethoxy)phosphazene was added to 1000g of MDI-100, and after stirring, 125g was placed in a four-necked flask, and the temperature was kept constant in a 55°C oil bath. When the material temperature reached 50°C, 561g of the highly reactive PBA2000 obtained in Preparation Example 2 was added to the flask, mechanical stirring was started, and the material temperature was raised to 80°C by an oil bath, and the reaction was carried out at this temperature for 3 hours. The product was a prepolymer with an NCO content of 9.03%. 100g of the prepolymer was weighed in a 100mL glass bottle, and stored in a constant temperature and humidity chamber at a temperature of 35°C and a humidity of 40% for sample shelf life test. The sample appearance was observed after 30 days and 100 days, and the sample viscosity and NCO were tested to obtain the sample shelf life data.

[0058] Comparative Example 1

[0059] Compared with Example 1, the only difference is that no phosphazene auxiliary agent is added, and the other operations are the same.

[0060] Comparative Example 2

[0061] Compared with Example 3, the only difference is that no phosphazene auxiliary agent is added, and the other operations are the same.

[0062] Comparative Example 3

[0063] Compared with Example 4, the only difference is that no phosphazene auxiliary agent is added, and the other operations are the same.

[0064] Comparative Example 4

[0065] Compared with Example 5, the only difference is that no phosphazene auxiliary agent is added, and the other operations are the same.

[0066] The above-mentioned embodiment and comparative example data are shown in the table below. It can be seen from the shelf life tracking that the shelf life of the prepolymer prepared by adding isocyanate with phosphazene additive and high-reactivity polyol can be extended by more than 6 times, which can indicate that phosphazene additives have a positive effect on extending the shelf life of the prepolymer. Among them, hexa(ethoxy)phosphazene has the best effect in extending the shelf life of the prepolymer due to its good nucleophilicity, small steric hindrance and strong molecular stability.

[0067] A phosphazene stabilizer is added to an isocyanate compound to prepare a prepolymer compound with a polyol. Since the phosphazene compound in the system is a Lewis acid, the catalyst introduced in the polyol production process can be captured in the prepolymer compound to prevent the catalyst from catalyzing the reaction between isocyanate and carbamate to form cross-linked macromolecules during storage, thereby causing the product to deteriorate. The compatibility of the isocyanate compound with different active polyols is improved, and the storage stability of the isocyanate prepolymer compound is improved.

[0068]

[0069] It is easy to understand that the above embodiments are only examples for clear explanation and do not mean that the present invention is limited thereto. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the present invention.

Claims

1. An isocyanate prepolymer composition, characterized in that: The composition contains isocyanate prepolymer and phosphazene compound; Wherein, the weight ratio of the phosphazene compound to the isocyanate compound is (0.001-1.0):100, preferably (0.003-0.01):

100.

2. The composition according to claim 1, characterized in that The isocyanate prepolymer is a prepolymer obtained by the reaction of isocyanate and an active hydrogen-containing polyol; Preferably, the isocyanate is one or more of aliphatic isocyanate, alicyclic isocyanate, aromatic isocyanate, and compounds containing the above isocyanate structures, preferably one or more of diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, urethane-modified isocyanate, and carbodiimide-modified isocyanate; Preferably, the active hydrogen-containing polyol is one or more of 2-3-valent polyether or polyester polyols with a molecular weight of 100-3000, preferably one or more of C2020, PBA2000, C1010, and PTMG2000.

3. The composition according to claim 1 or 2, characterized in that The structure of the phosphazene compound is as follows: Wherein, R is C1-C18 alkoxy and / or chlorine, preferably one or more of C1-C3 alkoxy.

4. The composition according to claim 3, characterized in that The phosphazene compounds include hexachlorophosphazene and / or phosphazene compounds obtained by substitution reaction of hexachlorophosphazene with sodium primary alcohol of C1-C18.

5. A method for preparing an isocyanate prepolymer composition, wherein the composition is the isocyanate prepolymer composition according to any one of claims 1 to 4, characterized in that: The preparation method comprises adding the phosphazene compound during the isocyanate prepolymerization process.

6. A method for preparing a phosphazene compound, wherein the compound is the phosphazene compound according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: The sodium primary alcohol of C1-C18 is reacted with hexachlorophosphazene in a solvent, washed with water to obtain a crude product, and recrystallized to obtain the phosphazene compound.

7. The method according to claim 6, characterized in that In the method, the molar ratio of primary alcohol sodium to hexachlorophosphazene is (6.0-6.6):

1.

8. Use of an isocyanate prepolymer composition, wherein the composition is the isocyanate prepolymer composition according to any one of claims 1 to 4, or is a composition prepared by the preparation method according to claim 5, and the composition is used as an isocyanate prepolymer with high storage stability, preferably as a raw material prepolymer for producing polyurethane adhesives, coatings, and soft foams.

Images