Concrete surface sealers, methods of making the same, and concrete

Abstract

The application belongs to the technical field of new chemical materials, and provides a concrete surface pore sealing agent, a preparation method thereof and concrete. The concrete surface pore sealing agent comprises the following components in parts by weight: 30-50 parts of water-based epoxy resin, 5-15 parts of nano silicon dioxide, 8-12 parts of microcapsule material, 3-8 parts of modified aerogel, 10-20 parts of curing agent, 1-3 parts of dispersing agent and 20-40 parts of water. The water-based epoxy resin fills the pores on the surface and in the interior of the concrete after curing to form a continuous sealing film; the nano silicon dioxide fills the micropores formed by cement hydration and reacts with the cement hydration product to generate C-S-H gel to further densify the matrix structure; the modified aerogel blocks the heat conduction path and has hydrophobicity at the same time, so that the rise of the thermal conductivity caused by water absorption of the pores can be avoided. The microcapsule material will gradually hydrolyze and break in the alkaline environment of the concrete to release silica gel to fill the new cracks, so that the durability of the concrete is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new chemical materials, in particular to a concrete surface pore sealing agent, a preparation method thereof and concrete. BACKGROUND

[0002] As the core substrate of new wall materials, the performance of concrete directly determines the energy saving, durability and safety level of buildings. New wall materials must meet the stringent requirements of low thermal conductivity, high impermeability and long durability. However, the pore structure of traditional concrete wall materials has inherent defects. The connected pores formed by cement hydration and the bubble pores introduced during construction result in a very high thermal conductivity, far exceeding the energy saving standard of new wall materials. In addition, this pore network provides a transmission channel for erosion media such as water and chloride ions, resulting in insufficient impermeability and durability of the material. Traditional walls usually have problems such as carbonation and steel corrosion after 5-10 years of service, and the related maintenance cost can account for more than 30% of the whole life cycle cost of the building. For the pore problem, existing technologies such as surface coating type pore sealing agents mainly rely on physical plugging of surface pores, but have the key defects of weak adhesion to the matrix and easy falling off during long-term service, and cannot completely solve the internal pore problem. In addition, existing technologies generally lack effective regulation and control ability of thermal conductivity, which has obvious short board in meeting the requirements of new wall materials. SUMMARY

[0003] The present application aims to overcome the problems of high thermal conductivity, poor impermeability and durability of concrete wall materials in the prior art, and provides a concrete surface pore sealing agent, a preparation method thereof and concrete.

[0004] In order to achieve the above-mentioned application purpose, the present application provides the following technical solutions:

[0005] The present application provides a concrete surface pore sealing agent, which comprises the following components by weight:

[0006] 30-50 parts of water-based epoxy resin, 5-15 parts of nano-silica, 8-12 parts of microcapsule material, 3-8 parts of modified aerogel, 10-20 parts of curing agent, 1-3 parts of dispersing agent and 20-40 parts of water.

[0007] As a preferred, the water-based epoxy resin comprises bisphenol A type water-based epoxy resin; the epoxy equivalent weight of the bisphenol A type water-based epoxy resin is 450 g / eq-550 g / eq.

[0008] As a preferred, the particle size of the nano-silica is 20 nm-50 nm, and the specific surface area is 200 m 2 / g-300 m 2 / g.

[0009] Preferably, the microcapsule material comprises an inner core and an outer shell, the inner core is a silicic acid gel, and the outer shell is polylactic acid.

[0010] Preferably, the modified aerogel is a silica aerogel modified by a silane coupling agent.

[0011] Preferably, the curing agent comprises one or more of a polyether amine, an alicyclic amine, a modified aliphatic amine, and gamma-glycidoxypropyltrimethoxysilane.

[0012] Preferably, the dispersant comprises one or both of sodium polyacrylate and gamma-aminopropyltrimethoxysilane.

[0013] The present application also provides a method for preparing a concrete surface pore sealing agent, comprising the following steps:

[0014] The components are mixed to obtain the concrete surface pore sealing agent.

[0015] The present application also provides the use of the concrete surface pore sealing agent in concrete.

[0016] The present application also provides a concrete, comprising the following components in parts by weight:

[0017] The concrete comprises cement 90-110 parts, aggregate 150-200 parts, water 40-60 parts, and the concrete surface pore sealing agent 3-8 parts.

[0018] The technical scheme of the present application has the following advantages:

[0019] The present application provides a concrete surface pore sealing agent, comprising the following components in parts by weight: water-based epoxy resin 30-50 parts, nano-silica 5-15 parts, microcapsule material 8-12 parts, modified aerogel 3-8 parts, curing agent 10-20 parts, dispersant 1-3 parts, and water 20-40 parts. The water-based epoxy resin and the nano-silica synergistically form an "organic-inorganic" interpenetrating network structure: the water-based epoxy resin fills the pores on the surface and inside the concrete after curing, forming a continuous sealing film; the nano-silica fills the micropores formed by cement hydration and reacts with the cement hydration products to generate C-S-H gel, further densifying the matrix structure. The three-dimensional porous structure of the modified aerogel blocks the heat conduction path, effectively reducing the thermal conductivity. At the same time, the modified aerogel also has hydrophobicity, which can avoid the increase in thermal conductivity caused by water absorption in the pores, so that the material can balance the thermal insulation performance and impermeability. Finally, the microcapsule material will gradually hydrolyze and break down in the alkaline environment of the concrete, releasing silicic acid gel to fill the newly generated cracks, achieving "dynamic repair during the hardening stage of the concrete", and further improving the durability of the concrete. DETAILED DESCRIPTION

[0020] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0021] This invention provides a concrete surface sealing agent, comprising the following components in parts by weight:

[0022] The mixture consists of 30-50 parts waterborne epoxy resin, 5-15 parts nano-silica, 8-12 parts microcapsule material, 3-8 parts modified aerogel, 10-20 parts curing agent, 1-3 parts dispersant, and 20-40 parts water.

[0023] In this invention, the waterborne epoxy resin is used in 30-50 parts by weight, preferably 35-45 parts, more preferably 37-43 parts, and even more preferably 40 parts.

[0024] In this invention, the amount of nano-silica by weight is 5-15 parts, preferably 7-13 parts, more preferably 8-12 parts, and even more preferably 10 parts.

[0025] In this invention, the microcapsule material is 8-12 parts by weight, preferably 8.5-11.5 parts, more preferably 9-11 parts, and even more preferably 10 parts.

[0026] In this invention, the modified aerogel is 3-8 parts by weight, preferably 4-7 parts, more preferably 5-6 parts, and even more preferably 5.5 parts.

[0027] In this invention, the curing agent is used in 10-20 parts by weight, preferably 12-18 parts, more preferably 14-16 parts, and even more preferably 15 parts.

[0028] In this invention, the dispersant is 1-3 parts by weight, preferably 1.5-2.5 parts, more preferably 1.7-2.3 parts, and even more preferably 2 parts.

[0029] In this invention, the water is used in 20-40 parts by weight, preferably 25-35 parts, more preferably 27-33 parts, and even more preferably 30 parts.

[0030] In this invention, the waterborne epoxy resin includes bisphenol A type waterborne epoxy resin; the epoxy equivalent of the bisphenol A type waterborne epoxy resin is preferably 450g / eq-550g / eq, more preferably 470g / eq-530g / eq, and even more preferably 500g / eq.

[0031] In the present application, the particle size of the nanosilica is preferably 20-50 nm, further preferably 30-40 nm, and more preferably 35 nm; the specific surface area is preferably 200-300 m 2 / g, further preferably 220-280 m 2 / g, further preferably 220-280 m 2 / g, further preferably 220-280 m 2 / g, further preferably 220-280 m 2 / g.

[0032] In the present application, the microcapsule material comprises an inner core and an outer shell, wherein the inner core is a silica gel and the outer shell is polylactic acid.

[0033] In the present application, the preparation method of the microcapsule material comprises the following steps:

[0034] (1) mixing tetraethyl orthosilicate and ethanol to obtain a first solution; mixing the first solution and water to obtain a second solution; adding ammonia water dropwise to the second solution to perform a reaction, distilling after the reaction is completed to obtain a precursor;

[0035] (2) mixing polylactic acid and dichloromethane to obtain a third solution; mixing polyvinyl alcohol and water to obtain a fourth solution;

[0036] (3) mixing the precursor and the fourth solution uniformly, then slowly adding the third solution to perform emulsification to obtain an emulsion; distilling the emulsion, and cooling to room temperature to obtain a suspension; sequentially performing water washing, filtering and drying on the suspension to obtain the microcapsule material.

[0037] In the present application, the mass ratio of the tetraethyl orthosilicate, ethanol and water in step (1) is preferably (10-15):(5-10):(5-8), further preferably (11-14):(6-9):(6-7), and more preferably 12.5:7.5:6.5; the mass fraction of the ammonia water is preferably 23%-27%, further preferably 24%-26%, and more preferably 25%; the pH of the system is adjusted by adding ammonia water and is preferably 8-9, further preferably 8.2-8.8, and more preferably 8.5; the temperature of the reaction is preferably 20-30℃, further preferably 22-28℃, and more preferably 25℃; and the time is preferably 2-3 h, further preferably 2.2-2.8 h, and more preferably 2.5 h.

[0038] In the present application, the molecular weight of the polylactic acid in step (2) is preferably 5000-10000, further preferably 6000-9000, and more preferably 7500; the polymerization degree of the polyvinyl alcohol is preferably 1700-1800, further preferably 1720-1780, and more preferably 1750; and the mass ratio of polylactic acid, dichloromethane, polyvinyl alcohol, and water is preferably (8-12):(15-20):(1-2):(50-60), further preferably (9-11):(16-19):(1.2-1.8):(52-58), and more preferably 10:17.5:1.5:55.

[0039] In the present application, the mass ratio of the polylactic acid in step (2) to the tetraethyl orthosilicate in step (1) is (8-12):(10-15), further preferably (9-11):(11-14), and more preferably 10:12.5.

[0040] In the present application, the rotation speed of the emulsification in step (3) is preferably 8000r / min-10000r / min, further preferably 8500r / min-9500r / min, and more preferably 9000r / min; and the time is preferably 20min-30min, further preferably 22min-28min, and more preferably 25min.

[0041] In the present application, the modified aerogel is a silica aerogel modified by a silane coupling agent.

[0042] In the present application, the silane coupling agent includes one or both of methacryloyloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0043] In the present application, the preparation method of the modified aerogel includes the following steps:

[0044] The silica aerogel is placed in a silane coupling agent solution, and then subjected to reaction and filtration in sequence, the obtained filter cake is washed with ethanol, and finally dried to obtain the modified aerogel.

[0045] In the present application, the solvent of the silane coupling agent solution is preferably ethanol, the mass fraction of the silane coupling agent solution is preferably 5%-10%, further preferably 6%-9%, and more preferably 7.5%; and the mass ratio of the silane coupling agent in the silane coupling agent solution to the silica aerogel powder is preferably (2-5):100, further preferably (3-4):100, and more preferably 3.5:100.

[0046] In the present application, the temperature of the reaction is preferably 40-60℃, further preferably 45-55℃, more preferably 50℃; the time is preferably 2-4h, further preferably 2.5-3.5h, more preferably 3h.

[0047] In the present application, the curing agent comprises one or more of polyether amine, alicyclic amine, modified fatty amine, and γ-glycidyl ether oxypropyl trimethoxysilane.

[0048] In the present application, the dispersant comprises one or both of sodium polyacrylate and γ-aminopropyl trimethoxysilane.

[0049] The present application also provides a preparation method of a concrete surface pore sealing agent, comprising the following steps:

[0050] Mixing the components to obtain the concrete surface pore sealing agent.

[0051] In the present application, the process of mixing the components comprises the following steps:

[0052] (1) mixing the water-based epoxy resin, nano-silica, dispersant and water, and sequentially performing dispersion and ultrasonic treatment to obtain a first dispersion liquid;

[0053] (2) adding the microcapsule material and modified aerogel to the first dispersion liquid and performing dispersion to obtain a second dispersion liquid;

[0054] (3) adding the curing agent to the second dispersion liquid and stirring to obtain the concrete surface pore sealing agent.

[0055] In the present application, the rotation speed of the dispersion in step (1) is preferably 2000-3000r / min, further preferably 2200-2800r / min, more preferably 2500r / min; the time of the dispersion is preferably 30-60min, further preferably 40-50min, more preferably 45min; the power of the ultrasonic treatment is preferably 200-500W, further preferably 300-400W, more preferably 350W; the time of the ultrasonic treatment is preferably 10-30min, further preferably 15-25min, more preferably 20min.

[0056] In the present application, the rotation speed of the dispersion in step (2) is preferably 500-800r / min, further preferably 600-700r / min, more preferably 650r / min; the time of the dispersion is preferably 15-30min, further preferably 20-25min, more preferably 22min.

[0057] In the present application, the rotating speed of the stirring in step (3) is preferably 300 r / min-500 r / min, further preferably 350 r / min-450 r / min, and more preferably 400 r / min; and the stirring time is preferably 10 min-20 min, further preferably 12 min-18 min, and more preferably 15 min.

[0058] The present application also provides the use of the concrete surface pore sealing agent in concrete.

[0059] The present application also provides a concrete comprising the following components in parts by weight:

[0060] cement 90-110 parts, aggregate 150-200 parts, water 40-60 parts, and concrete surface pore sealing agent 3-8 parts.

[0061] In the present application, the cement is in a weight fraction of 90-110 parts, preferably 92-108 parts, further preferably 95-105 parts, and more preferably 100 parts.

[0062] In the present application, the aggregate is in a weight fraction of 150-200 parts, preferably 160-190 parts, further preferably 170-180 parts, and more preferably 175 parts.

[0063] In the present application, the water is in a weight fraction of 40-60 parts, preferably 45-55 parts, further preferably 47-53 parts, and more preferably 50 parts.

[0064] In the present application, the concrete surface pore sealing agent is in a weight fraction of 3-8 parts, preferably 4-7 parts, further preferably 5-6 parts, and more preferably 5.5 parts.

[0065] In the present application, the cement is preferably P・O 42.5 grade Portland cement; the aggregate preferably comprises natural sand and gravel, and the mass ratio of the natural sand and gravel is preferably 1: (2.5-3.5), further preferably 1: (2.7-3.3), and more preferably 1:3.

[0066] In the present application, the preparation method of the concrete comprises the following steps:

[0067] The components are mixed, and first stirring and second stirring are sequentially performed, and then the concrete is obtained after pouring and molding and curing.

[0068] In the present application, the rotation speed of the first stirring is preferably 200 r / min-300 r / min, further preferably 220 r / min-280 r / min, and more preferably 250 r / min; the time of the first stirring is preferably 2 min-3 min, further preferably 2.2 min-2.8 min, and more preferably 2.5 min; the rotation speed of the second stirring is preferably 600 r / min-800 r / min, further preferably 650 r / min-750 r / min, and more preferably 700 r / min; the time of the second stirring is preferably 3 min-5 min, further preferably 3.5 min-4.5 min, and more preferably 4 min.

[0069] In the present application, the temperature of the curing is preferably 18℃-22℃, further preferably 19℃-21℃, and more preferably 20℃; the relative humidity is preferably ≥90%, further preferably ≥92%, and more preferably ≥93%; and the time is preferably 26 days-30 days, further preferably 27 days-29 days, and more preferably 28 days.

[0070] If the specific experimental steps or conditions are not indicated in the examples, the operation or conditions can be carried out according to the conventional experimental steps described in the literature in the field. If the reagents or instruments used are not indicated by the manufacturer, they are all conventional reagent products that can be obtained by purchase.

[0071] Example 1: The present example provides a concrete surface sealing agent, which comprises the following components in parts by weight:

[0072] 40 parts of bisphenol A type waterborne epoxy resin (epoxy equivalent weight 500 g / eq), 10 parts of nano-silicon dioxide (particle size 35 nm, specific surface area 250 m 2 / g), 10 parts of microcapsule material (including silica gel core and polylactic acid shell), 5.5 parts of modified aerogel (γ-aminopropyl triethoxysilane modified silica aerogel), 15 parts of curing agent (including 10 parts of polyether amine, 5 parts of γ-glycidyl ether oxypropyl trimethoxysilane), 2 parts of dispersing agent (including 1 part of sodium polyacrylate and 1 part of γ-aminopropyl trimethoxysilane), and 30 parts of water.

[0073] The preparation method of the microcapsule material comprises the following steps:

[0074] The tetraethyl orthosilicate and ethanol are mixed, stirred at a temperature of 25 DEG C and a rotating speed of 400 r / min for 15 min to obtain a first solution; water is added into the first solution, and the stirring is continued at a temperature of 25 DEG C and a rotating speed of 400 r / min for 30 min to obtain a second solution; the mass ratio of the tetraethyl orthosilicate, ethanol and water is 12.5:7.5:6.5; then ammonia water with a mass fraction of 25% is added dropwise into the second solution to adjust the pH of the system to 8.5, the stirring speed is maintained at 400 r / min, and the reaction is carried out at 25 DEG C for 2.5 h; after the reaction is completed, ethanol is removed by distillation under reduced pressure at a temperature of 45 DEG C and a pressure of 4.5 kPa to obtain a precursor; polylactic acid (with a molecular weight of 7500) and dichloromethane are mixed, and ultrasonic treatment is carried out at a temperature of 30 DEG C and a power of 350 W for 20 min to obtain a third solution; polyvinyl alcohol (with a polymerization degree of 1750) and water are mixed, heated to 65 DEG C, stirred until completely dissolved, and then cooled to room temperature to obtain a fourth solution; the mass ratio of the polylactic acid, dichloromethane, polyvinyl alcohol and water is 10:17.5:1.5:55, and the mass ratio of the polylactic acid and tetraethyl orthosilicate is 10:12.5; the precursor obtained above and the fourth solution are mixed, the third solution is slowly added after uniform stirring, and the emulsion is obtained by using a high-shear emulsifier (with a rotating speed of 9000 r / min) for 25 min; the emulsion is transferred into a rotary evaporator, and dichloromethane is removed by distillation under reduced pressure at a temperature of 45 DEG C, a vacuum degree of 9 kPa and a rotating speed of 250 r / min for 5 h; after the distillation is completed, the suspension is obtained after cooling to room temperature; the suspension is washed with water (the rotating speed of water washing is 9000 r / min, the number of times of water washing is 4, and the time of each water washing is 10 min), and the filter cake is collected after filtration, frozen at -40 DEG C and dried for 30 h to obtain a microcapsule material.

[0075] The preparation method of the modified aerogel comprises the following steps:

[0076] The silica aerogel is placed in a γ-aminopropyl triethoxysilane solution (the solvent is ethanol, the mass fraction of γ-aminopropyl triethoxysilane in the γ-aminopropyl triethoxysilane solution is 7.5%, and the mass ratio of γ-aminopropyl triethoxysilane to silica aerogel powder is 3.5:100), and the reaction is carried out at 50 DEG C for 3 h; after the reaction is completed, the filter cake is obtained and washed with ethanol for 3 times; finally, the modified aerogel is obtained by drying at a temperature of 70 DEG C and a vacuum degree of 9 kPa for 5 h.

[0077] The preparation method of the concrete surface pore sealing agent also comprises the following steps:

[0078] The aqueous epoxy resin, nano-silica, dispersant and water were mixed, dispersed at 2500 r / min for 45 min, and then ultrasonically treated at 350 W for 20 min to obtain a first dispersion liquid; the microcapsule material and modified aerogel were added to the first dispersion liquid, dispersed at 650 r / min for 22 min to obtain a second dispersion liquid; the curing agent was added to the second dispersion liquid, stirred at 400 r / min for 15 min to obtain the concrete surface sealing agent.

[0079] Examples 2-5

[0080] In Control Example 1, the weight fractions of the components in the concrete surface sealing agent were adjusted while other conditions remained unchanged. Specifically, the weight fractions of the components in the concrete surface sealing agent in Examples 1-5 are shown in Table 1.

[0081] Table 1 Weight fractions of the components in the concrete surface sealing agent in Examples 1-5

[0082] Case Aqueous epoxy resin Nanosilica Microcapsule material Modified aerogel Curing agent Dispersant Water Example 1 40 10 10 5.5 15 2 30 Example 2 35 7 8.5 4 12 1.5 25 Example 3 45 13 11.5 7 18 2.5 35 Example 4 37 8 9 5 14 1.7 27 Example 5 50 15 15 8 20 3 40

[0083] Comparative Example 1

[0084] In Control Example 1, the addition of the microcapsule material was omitted while other conditions remained unchanged.

[0085] Comparative Example 2

[0086] In Control Example 1, the addition of the modified aerogel was omitted while other conditions remained unchanged.

[0087] Comparative Example 3

[0088] In Control Example 1, the addition of the nano-silica was omitted while other conditions remained unchanged.

[0089] Experimental Example

[0090] The concrete surface sealing agents prepared in Examples 1-5 and Comparative Examples 1-3 were applied to prepare concrete. Specifically, in Example 1, 100 parts of cement (P·O 42.5 grade Portland cement), 175 parts of aggregate (mass ratio of natural sand and gravel of 1:3), 50 parts of water, and 5.5 parts of the concrete surface sealing agent were mixed, stirred at 250 r / min for 2.5 min, and then stirred at 700 r / min for 4 min, and then poured and molded, and cured under conditions of a temperature of 20°C and a relative humidity of 92.5% for 28 days to obtain concrete.

[0091] The properties of each concrete were tested, wherein the impermeability test was in accordance with GB / T 50082-2009, the thermal conductivity test was in accordance with GB / T 10294-2008, and the carbonation depth test was in accordance with GB / T 50082-2009; the performance test results of Examples 1-5 and Comparative Examples 1-3 were finally obtained and recorded in Table 2.

[0092] Table 2 Performance test results of Examples 1-5 and Comparative Examples 1-3

[0093] Case Permeation resistance rating Thermal conductivity W / (m・K) Carbonization depth (56 days, mm) Example 1 P13 0.102 3.2 Example 2 P12 0.105 3.5 Example 3 P12 0.104 3.3 Example 4 P12 0.107 3.9 Example 5 P12 0.106 3.8 Comparative Example 1 P10 0.125 6.8 Comparative Example 2 P11 0.198 4.6 Comparative Example 3 P11 0.120 4.3

[0094] As can be seen from Table 2, the concrete surface sealing agent of the specific formula of the present application applied to the concrete, the obtained concrete has excellent impermeability and durability, and also has good thermal insulation performance.

[0095] Obviously, the above examples are only examples for clearly illustrating but not limitation to the embodiments. Other different forms of changes or variations can be made on the basis of the above description for those skilled in the art. Here, it is not necessary and also impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A concrete surface sealing agent, characterized in that, The components include the following parts by weight: The composition includes 30-50 parts of waterborne epoxy resin, 5-15 parts of nano-silica, 8-12 parts of microcapsule material, 3-8 parts of modified aerogel, 10-20 parts of curing agent, 1-3 parts of dispersant and 20-40 parts of water. The microcapsule material comprises a core and a shell, wherein the core is a silica gel and the shell is polylactic acid.

2. The concrete surface sealing agent according to claim 1, characterized in that, The waterborne epoxy resin includes bisphenol A type waterborne epoxy resin; the epoxy equivalent of the bisphenol A type waterborne epoxy resin is 450g / eq-550g / eq.

3. The concrete surface sealing agent according to claim 1, characterized in that, The nano-silica has a particle size of 20nm-50nm and a specific surface area of ​​200m². 2 / g-300m 2 / g.

4. The concrete surface sealing agent according to claim 1, characterized in that, The modified aerogel is a silica aerogel modified with a silane coupling agent.

5. The concrete surface sealing agent according to claim 4, characterized in that, The curing agent includes one or more of polyetheramine, alicyclic amine, and modified fatty amine.

6. The concrete surface sealing agent according to claim 5, characterized in that, The dispersant includes one or both of sodium polyacrylate and γ-aminopropyltrimethoxysilane.

7. The method for preparing the concrete surface sealing agent according to any one of claims 1-6, characterized in that, Includes the following steps: The components are mixed to obtain a concrete surface sealing agent.

8. The application of the concrete surface sealing agent according to any one of claims 1-6 in concrete.

9. A type of concrete, characterized in that, The components include the following parts by weight: The mixture comprises 90-110 parts cement, 150-200 parts aggregate, 40-60 parts water, and 3-8 parts of the concrete surface sealing agent as described in any one of claims 1-6.