Flame-retardant rigid polyurethane foams and methods for making the same

Abstract

The present application belongs to the technical field of preparation of polyether polyol, and particularly relates to a flame-retardant rigid foam polyether polyol with improved bio-based content and a preparation method thereof.The preparation method of the flame-retardant rigid foam polyether polyol with improved bio-based content comprises the following steps: inputting bio-based raw materials, conventional bio-based initiators, nitrogen-containing compounds and catalysts, vacuum heating, dropping alkylene oxide, internal pressure reaction to obtain a prepolymer; inputting phosphorus-containing compounds, heating and bubbling, dropping alkylene oxide for end-capping synthesis, degassing after reaction, cooling, and discharging to obtain the bio-based flame-retardant rigid foam polyether polyol.The present application provides a preparation method of the bio-based flame-retardant rigid foam polyether polyol, the prepared rigid foam polyether polyol has high bio-based content, greatly reduces the application of petrochemical raw materials, and has good flame-retardant performance.

Description

Technical Field

[0001] This invention belongs to the technical field of polyether polyol preparation, specifically relating to flame-retardant rigid foam polyether polyol with increased bio-based content and its preparation method. Background Technology

[0002] Due to the depletion of petrochemical resources, bio-based alternatives are gradually being discovered. For example, vegetable oils, cashew nut shell oil, corn stalks, and other bio-based renewable raw materials are used to synthesize polyols or isocyanates, which are then used as the main raw materials for polyurethane materials. After various chemical modifications, these materials are foamed to obtain various types of polyurethane foam materials.

[0003] However, the characteristics of bio-based raw materials also bring application drawbacks after substitution. For example, the preparation method of plant-based polyether polyol disclosed in CN115572385A uses alkanolamine to open the ring chain of epoxidized soybean oil and mixes castor oil, hydrogenated soybean oil and other oils to replace petrochemical raw materials. This solves the turbidity and stratification phenomenon caused by excessive substitution of oils in bio-based raw materials, but at the same time, it greatly reduces the flame retardancy of polyether polyol. For example, CN112759753A discloses a preparation method of phosphorus and nitrogen synergistic flame retardant polyether polyol. It uses the Mannichfa method to improve the flame retardancy of conventional polyether polyol by adding phosphorus and nitrogen elements to the aromatic phosphate raw material modified by alkanolamine. However, the raw materials used are all petroleum-based raw materials, which cannot reduce the utilization of petrochemical resources and are not bio-based polyether polyols. For example, CN110283207A discloses a phosphorus-nitrogen synergistic flame-retardant polyether polyol and its preparation method, which uses hexamethylol melamine and phosphate ester diol for ether exchange. This can serve as a technical reference for improving the flame retardancy of polyether polyols, but its flame-retardant method and technology are not feasible in the field of polyether polyol synthesis with bio-based raw material substitution. Similarly, CN105199096 discloses the preparation and application of nitrogen-phosphorus structured flame-retardant polyether polyols, which uses the Mannich process to modify phosphate ester raw materials. The process of synthesizing polyether polyols with polycyanamide does not involve the synthesis of polyether polyols and cannot provide technical applications for the synthesis of polyethers under conditions of large-scale substitution of bio-based raw materials. Furthermore, the flame-retardant polyether polyols, combined polyethers, polyurethane foams and their preparation methods disclosed in CN104004175A also use the Mannich method to modify phosphite raw materials with alkanolamines and introduce phosphorus and nitrogen elements to modify the flame retardancy of conventional non-bio-based polyethers. This process cannot provide technical reference for the flame retardant and reinforcing properties in the field of bio-based polyether polyols.

[0004] In the field of rigid polyurethane foam, compared with conventional sucrose-based rigid polyurethane foam products such as R4110, bio-based polyether polyols tend to have lower strength and flame retardant properties. How to improve strength and flame retardancy under the condition of large-scale replacement of bio-based raw materials is a key application point for bio-based polyether polyols. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for preparing bio-based flame-retardant rigid foam polyether polyol. The prepared rigid foam polyether polyol has a high bio-based content, which greatly reduces the use of petrochemical raw materials. At the same time, through halogen-free flame retardancy, the rigid foam polyether polyol can have good flame retardant performance after using bio-based raw materials to replace petrochemical resources.

[0006] The preparation method of flame-retardant rigid foam polyether polyol with increased bio-based content according to the present invention includes the following steps:

[0007] (1) Pre-dropping stage: According to the initial feed ratio, add bio-based raw materials, conventional bio-based initiators, nitrogen-containing compounds and catalysts, vacuum heat up to 60-80℃, add epoxy alkane for reaction, react under internal pressure for 2-3 hours to obtain prepolymer;

[0008] (2) High temperature reaction: According to the initial feed ratio, add phosphorus-containing compounds, stir evenly, raise the temperature and vacuum, and when the temperature reaches 110-120℃, vacuum, start bubbling, and react for 2-3 hours.

[0009] (3) Secondary reaction: Maintain the temperature and add epoxy alkane dropwise for end-capping synthesis. After the dropwise addition is complete, the internal pressure reaction is carried out for 2-3 hours. After degassing, the temperature is lowered to 95-105℃ and the material is discharged to obtain bio-based flame-retardant rigid foam polyether polyol.

[0010] Bio-based raw materials account for 38.8 wt.%-48.1 wt.% of the initial feed amount; conventional bio-based initiators account for 34.9 wt.%-38.6 wt.% of the initial feed amount; nitrogen-containing compounds account for 14.1 wt.%-21.1 wt.% of the initial feed amount; phosphorus-containing compounds account for 7.2 wt.%-10.8 wt.% of the initial feed amount; the catalyst in step (1) accounts for 1.4 wt.%-1.5 wt.% of the initial feed amount; and the amount of epoxide alkane added in step (1) is more than 60 wt.% of the conventional bio-based initiator.

[0011] The initial feed amount is the total mass of bio-based raw materials, conventional bio-based initiators, nitrogen-containing compounds, and catalysts.

[0012] The bio-based raw material is an epoxy oil, specifically one of the following: epoxidized soybean oil, epoxidized fatty acid methyl ester, epoxidized fatty acid butyl ester, or epoxidized fatty acid octyl ester. The epoxy value of epoxidized soybean oil is 6.0-6.8%; that of epoxidized fatty acid methyl ester is 3.2-3.5%; that of epoxidized fatty acid butyl ester is 3-4%; and that of epoxidized fatty acid octyl ester is 3.5-4.5%.

[0013] Conventional bio-based initiators are small molecule polyols, such as sucrose, glycerol, and palm oil, or one or more of these.

[0014] The nitrogen-containing compound is one of cyanuric acid, melamine, triazineamide, or carbamide.

[0015] The catalyst is one of triethylamine, dodecyltetradecyldimethylamine, N,N-dimethylaniline, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0016] The phosphorus-containing compound is one of dimethyl phosphite, diethyl phosphite, or diphenyl phosphite.

[0017] The epoxide is one or more of ethylene oxide, propylene oxide, and butane oxide.

[0018] After degassing in step (3), the temperature is lowered to 95-105℃, bubbled for 1-2 hours, and then cooled to 80-90℃. The material is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol.

[0019] A bio-based flame-retardant rigid foam polyether polyol is prepared by the aforementioned method for increasing the bio-based content of the flame-retardant rigid foam polyether polyol.

[0020] Specifically, the preparation method of the flame-retardant rigid foam polyether polyol with increased bio-based content includes the following steps:

[0021] (1) Pre-drop stage: Bio-based raw materials, conventional bio-based initiators, nitrogen-containing compounds and catalysts are added to the reactor. After leak testing and replacement, the temperature is raised to 60-80℃ under negative pressure of -0.09MPa, and epoxy alkane is added dropwise for reaction. The reaction is carried out under internal pressure for 2-3 hours to obtain the prepolymer.

[0022] (2) High temperature reaction: According to the initial feed ratio, add phosphorus-containing compounds, stir evenly, raise the temperature and draw a vacuum. When the temperature reaches 110-120℃ and the pressure is -0.09MPa, start bubbling and react for 2-3 hours.

[0023] (3) Secondary reaction: Maintain the temperature, add epoxy alkane dropwise for end-capping synthesis, after the dropwise addition is complete, internal pressure reaction for 2-3 hours, after degassing, cool down to 95-105℃, bubble for 1-2 hours and cool down to 80-90℃, and release the material to obtain bio-based flame retardant rigid foam polyether polyol.

[0024] The method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content according to the present invention firstly involves pre-drip liquefaction modification of sucrose and nitrogen-containing compounds with bio-based raw materials, conventional bio-based initiators, and nitrogen-containing compounds under the action of a catalyst, followed by addition of phosphorus-containing compounds, degassing at elevated temperature, high-temperature reaction, secondary feeding, and polymerization of epoxides to obtain the final product.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) The method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content of the present invention uses epoxy oil as bio-based raw material to replace part of the epoxy alkane petroleum-based raw material, thereby increasing the bio-based content of polyether polyol, with the proportion of bio-based raw material reaching more than 50%, and reducing carbon emissions.

[0027] (2) The method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content of the present invention modifies the bio-based raw material in terms of molecular structure by using phosphorus-containing compounds and introducing phosphorus elements, using nitrogen-containing compounds as initiators, and significantly improving the strength and structural flame retardancy of bio-based polyether polyol through the polymerization of epoxides and the synergistic effect of phosphorus and nitrogen. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments.

[0029] Unless otherwise specified, all raw materials used in the examples were commercially available. All weight percentages are by mass. The epoxy value of the epoxidized soybean oil in the following raw materials is 6.0-6.8%; the epoxy value of the epoxidized fatty acid methyl ester is 3.2-3.5%; the epoxy value of the epoxidized fatty acid butyl ester is 3-4%; and the epoxy value of the epoxidized fatty acid octyl ester is 3.5-4.5%.

[0030] Example 1

[0031] The method for preparing flame-retardant rigid foam polyether polyol A with increased bio-based content includes the following steps:

[0032] (1) Pre-dropping stage: In the reactor, 400g of epoxidized soybean oil, 240g of sucrose, 50g of palm oil, 129g of cyanuric acid, and 12g of triethylamine catalyst were added. After the reactor was tested for leaks and replaced, the pressure was evacuated to -0.09MPa under a nitrogen atmosphere and the temperature was raised to 60℃. After the temperature was raised, 166g of propylene oxide was added dropwise for reaction. After the addition was completed, the internal pressure was increased for 2 hours to obtain the prepolymer.

[0033] (2) High temperature reaction: After the internal pressure stabilizes, open the kettle and add 60g of dimethyl phosphite. After stirring the kettle for 5 minutes, raise the temperature and draw a vacuum. When the temperature reaches 110℃ and the vacuum is drawn to -0.09MPa, start bubbling and start the reaction for 2 hours.

[0034] (3) Secondary reaction: After the reaction is completed, maintain the temperature, close the vacuum, and start adding 180g of propylene oxide for end-capping synthesis. After the addition is completed, the internal pressure reaction is carried out for 2 hours. After the internal pressure is completed, degas for 30 minutes, cool down to 105℃, and then bubble with nitrogen for 2 hours to cool down to 80℃ to remove residual small molecules in the product. The product is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol A.

[0035] Example 2

[0036] The method for preparing the flame-retardant rigid foam polyether polyol B with increased bio-based content includes the following steps:

[0037] (1) Pre-dropping stage: In the reactor, 312g of epoxy fatty acid methyl ester, 240g of sucrose, 20g of glycerol, 50g of palm oil, 170g of triazine amide, and 12g of 2,4,6-tris(dimethylaminomethyl)phenol were added. After the reactor was tested for leaks and purged, the pressure was reduced to -0.09MPa under a nitrogen atmosphere and the temperature was raised to 80℃. After the temperature was raised, 160g of propylene oxide was added dropwise for reaction. After the addition was completed, the reaction was carried out under internal pressure for 2 hours to obtain the prepolymer.

[0038] (2) High temperature reaction: After the internal pressure stabilizes, add 79.8g of diphenyl phosphite to the kettle, stir for 5 minutes, raise the temperature and evacuate the vacuum. When the temperature reaches 110℃ and the vacuum is reduced to -0.09MPa, start bubbling and start the reaction for 2 hours.

[0039] (3) Secondary reaction: After the reaction is completed, maintain the temperature, close the vacuum, and start adding 167g of propylene oxide for end-capping synthesis. After the addition is completed, the internal pressure reaction is carried out for 2 hours. After the internal pressure is completed, degas for 30 minutes, cool down to 95℃, and bubble with nitrogen for 2 hours to cool down to 80℃ to remove residual small molecules in the product. The product is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol B.

[0040] Example 3

[0041] The method for preparing the flame-retardant rigid foam polyether polyol C with increased bio-based content includes the following steps:

[0042] (1) Pre-drop stage: In the reactor, 354g of butyl epoxide fatty acid, 240g of sucrose, 20g of glycerol, 50g of palm oil, 126g of melamine, and 12g of dodecyltetramethyldimethylamine catalyst were added. After the reactor was tested for leaks and replaced, the pressure was evacuated to -0.09MPa under a nitrogen atmosphere and the temperature was raised to 70℃. After the temperature was raised, 188g of propylene oxide was added dropwise for reaction. After the addition was completed, the internal pressure was increased for 3h to obtain the prepolymer.

[0043] (2) High temperature reaction: After the internal pressure stabilizes, open the kettle and add 61g of diethyl phosphite. After stirring for 5 minutes, raise the temperature and evacuate the vacuum. When the temperature reaches 120℃ and the vacuum is reduced to -0.09MPa, start bubbling and start the reaction for 2 hours.

[0044] (3) Secondary reaction: After the reaction is completed, maintain the temperature, close the vacuum, and start adding 250g of propylene oxide for end-capping synthesis. After the addition is completed, the internal pressure reaction is carried out for 3 hours. After the internal pressure is completed, degas for 30 minutes, cool down to 100℃, and bubble with nitrogen for 2 hours to cool down to 80℃ to remove residual small molecules in the product. The material is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol C.

[0045] Example 4

[0046] The method for preparing flame-retardant rigid foam polyether polyol D with increased bio-based content includes the following steps:

[0047] (1) Pre-dropping stage: In the reactor, 410g of octyl epoxide fatty acid, 240g of sucrose, 20g of glycerol, 50g of palm oil, 120g of carbamide, and 12g of N,N-dimethylaniline catalyst were added. After the reactor was tested for leaks and purged, the pressure was evacuated to -0.09MPa under a nitrogen atmosphere and the temperature was raised to 60℃. After the temperature was raised, 175g of ethylene oxide was added dropwise for reaction. After the addition was completed, the reaction was carried out under internal pressure for 2 hours to obtain the prepolymer.

[0048] (2) High temperature reaction: After the internal pressure stabilizes, open the kettle and add 92g of diphenyl phosphite. After stirring the kettle for 5 minutes, raise the temperature and draw a vacuum. When the temperature reaches 120℃ and the vacuum is drawn to -0.09MPa, start bubbling and start the reaction for 2 hours.

[0049] (3) Secondary reaction: After the reaction is completed, maintain the temperature, close the vacuum, and start adding 240g of propylene oxide for end-capping synthesis. After the addition is completed, the internal pressure reaction is carried out for 3 hours. After the internal pressure is completed, degas for 30 minutes, cool down to 95°C, and then bubble with nitrogen for 1 hour to cool down to 90°C to remove residual small molecules in the product. The product is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol D.

[0050] Comparative Example 1

[0051] A method for preparing polyether polyol B1 includes the following steps:

[0052] Add 325g sucrose, 50g solid sorbitol, 80g diethylene glycol, 255g palm oil, and 12g fatty amine catalyst to a reactor. After leak testing and purging, heat to 105℃ under negative pressure while maintaining a nitrogen atmosphere pressure of 0.13±0.02MPa inside the reactor. Add 787g propylene oxide dropwise. After the propylene oxide is added, keep the temperature high and continue the reaction for 3 hours until the pressure inside the reactor no longer decreases. After bubbling to remove monomers for 2 hours, cool to 80℃ and discharge to obtain polyether polyol B1.

[0053] Comparative Example 2

[0054] A method for preparing polyether polyol B2 includes the following steps:

[0055] Add 325g sucrose, 165g diethylene glycol, and 11.4g DMA catalyst to the reactor. After leak testing and purging, heat the reactor to 105℃ under negative pressure while maintaining a nitrogen atmosphere pressure of 0.13±0.02MPa. Add 913g propylene oxide dropwise. After the propylene oxide is added, keep the reactor warm and continue the reaction for 3 hours until the pressure inside the reactor no longer decreases. After bubbling to remove monomers for 2 hours, cool the reactor to 80℃ and discharge the material to obtain polyether polyol B2.

[0056] Comparative Example 3

[0057] A method for preparing polyether polyol B3 includes the following steps:

[0058] (1) Pre-dropping stage: In the reactor, add 400g of epoxidized soybean oil, 240g of sucrose, 50g of palm oil, 129g of cyanuric acid, 12g of triethylamine catalyst, and 60g of dimethyl phosphite. After the reactor is tested for leaks and purged, heat to 80°C under a nitrogen atmosphere and a vacuum of -0.09MPa. After the heating is completed, add 166g of propylene oxide for reaction. After the addition is completed, pressurize the reactor for 1 hour.

[0059] (2) Secondary reaction: The temperature was raised to 110℃, and 180g of propylene oxide was added dropwise for synthesis. After the addition was completed, the reaction was carried out under internal pressure for 3 hours. After the internal pressure was completed, the gas was degassed for 30 minutes, and the temperature was lowered to 105℃. Nitrogen bubbling was performed for 1 hour, and the temperature was lowered to 90℃ to remove residual small molecules in the product. The product was then discharged to obtain bio-based flame-retardant rigid foam polyether polyol B3. During the discharge process, a large amount of white flaky suspension was present. The product was turbid and opaque. After standing, it separated into layers. The upper layer was slightly turbid with low viscosity, while the lower layer was viscous and turbid. Conventional polyether polyols should be transparent, light yellow to brownish-red, transparent and homogeneous liquids. The polyether synthesized in Comparative Example 3 could not be used in the next step.

[0060] Comparative Example 4

[0061] A method for preparing polyether polyol B3 includes the following steps:

[0062] (1) Pre-dropping stage: In the reaction vessel, add 312g of epoxy fatty acid methyl ester, 240g of sucrose, 20g of glycerol, 50g of palm oil, 170g of triazine amide, and 12g of 2,4,6-tris(dimethylaminomethyl)phenol. After the vessel is tested for leaks and purged, heat to 80°C under a nitrogen atmosphere and a vacuum of -0.09MPa. After the heating is completed, add 160g of propylene oxide dropwise. After the addition is completed, pressurize the internal pressure for 1 hour.

[0063] After the internal pressure stabilizes, add 85g of methyl diphenyl phosphate to the kettle, stir for 5 minutes, raise the temperature, and apply a vacuum. When the temperature reaches 120℃ and -0.09MPa, start bubbling and start the reaction for 2 hours.

[0064] (2) Secondary reaction: After the reaction was completed, the temperature was maintained, the vacuum was closed, and 167g of propylene oxide was added dropwise for end-capping synthesis. After the addition was completed, the reaction was carried out under internal pressure for 2 hours. After the internal pressure was completed, the gas was degassed for 30 minutes, the temperature was lowered to 95℃, and nitrogen bubbling was performed for 1-2 hours. The temperature was then lowered to 80℃ to remove residual small molecules from the product. The product was then discharged to obtain bio-based flame-retardant rigid foam polyether polyol B4. The discharged B4 contained a small amount of residual sugar particles, the indicators were abnormal, the yield was low, and it became turbid and gradually separated after 10 days.

[0065] The polyether polyols prepared in Examples 1-4 and Comparative Examples 1, 2, and 4 above were tested for hydroxyl value according to GB 12008.3-1989 and viscosity according to GBT 12008.7-2010. The test results are shown in Table 1.

[0066] Table 1 Test Results of Polyether Polyols

[0067] Example 1 417 7894 56 Example 2 362 4518 52 Example 3 496 22534 60 Example 4 488 7689 53 Comparative Example 1 405 5830 40 Comparative Example 2 440 3460 23 Comparative Example 4 349 3167 52

[0068] The polyether polyols prepared in Examples 1-4 and Comparative Examples 1, 2, and 4 were compounded into composite materials according to the polyurethane foam formulation ratios in Table 2 below, and then mixed with PM200 at a ratio of 1:1 to produce polyurethane foam. The performance of the polyurethane foam was then tested.

[0069] Table 2. Polyurethane foam formulation and performance test results

[0070]

[0071] Among them, PC8 is MAY CATPC8 gel catalyst, 8815 is MAY M-8815 foam leveling agent, C305 is CASE polyether produced by Shandong Yinuowei New Material Co., Ltd., and TCPP is Taian Yarong flame retardant.

[0072] As shown in the table above, the bio-based content of the bio-based flame-retardant rigid foam polyether polyol of the present invention is much greater than that of conventional polyether polyols and bio-based polyether polyols. Under the condition that the strength is close to or better than that of conventional rigid foam polyethers and bio-based polyethers, the flame-retardant performance is greatly improved.

[0073] Of course, the above description is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the embodiments of the present invention. The present invention is also not limited to the above examples, and all equivalent changes and improvements made by those skilled in the art within the scope of the present invention should fall within the patent coverage of the present invention.

Claims

1. A method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content, characterized in that: Includes the following steps: (1) Pre-drop stage: According to the initial feed ratio, add bio-based raw materials, conventional bio-based initiators, nitrogen-containing compounds and catalysts, vacuum and heat to 60-80℃, add epoxy alkane for reaction, react under internal pressure for 2-3 hours to obtain prepolymer; The nitrogen-containing compound is one of cyanuric acid, melamine, triazine amide, and carbamide; the bio-based raw material is epoxy oil; the conventional bio-based initiator is a small molecule polyol, which is one or more of sucrose, glycerol, and palm oil. The catalyst is one of triethylamine, dodecyltetradecyl dimethyl tertiary amine, N,N-dimethylaniline, and 2,4,6-tris(dimethylaminomethyl)phenol, accounting for 1.4 wt.%-1.5 wt.% of the initial feed. In this step, the amount of epoxide added is more than 60 wt.% of the conventional bio-based initiator; the bio-based raw material accounts for 38.8 wt.%-48.1 wt.% of the initial feed; the conventional bio-based initiator accounts for 34.9 wt.%-38.6 wt.% of the initial feed; and the nitrogen-containing compound accounts for 14.1 wt.%-21.1 wt.% of the initial feed. (2) High temperature reaction: According to the initial feed ratio, add phosphorus-containing compounds, stir evenly, raise the temperature and vacuum, and when the temperature reaches 110-120℃, vacuum, start bubbling, and react for 2-3 hours. The phosphorus-containing compound is one of dimethyl phosphite, diethyl phosphite, or diphenyl phosphite; the phosphorus-containing compound accounts for 7.2 wt.%-10.8 wt.% of the initial feed amount. (3) Secondary reaction: Maintain the temperature and add epoxy alkane dropwise for end-capping synthesis. After the dropwise addition is complete, the internal pressure reaction is carried out for 2-3 hours. After degassing, the temperature is lowered to 95-105℃ and the material is released to obtain bio-based flame-retardant rigid foam polyether polyol.

2. The method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content according to claim 1, characterized in that: The epoxide is one or more of ethylene oxide, propylene oxide, and butane oxide.

3. The method for preparing flame-retardant rigid foam polyether polyol with increased bio-based content according to claim 1, characterized in that: After degassing in step (3), the temperature is lowered to 95-105℃, bubbled for 1-2 hours, and then cooled to 80-90℃. The material is then discharged to obtain bio-based flame-retardant rigid foam polyether polyol.

4. A bio-based flame-retardant rigid foam polyether polyol, characterized in that: It is prepared by the method of the flame-retardant rigid foam polyether polyol with increased bio-based content as described in any one of claims 1-3.

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