A double-sided water-blocking tape and a preparation method thereof

Abstract

The present application relates to the technical field of water-blocking tape, and particularly relates to a double-sided water-blocking tape and a preparation method thereof, the double-sided water-blocking tape comprises a polyester film surface layer, a base material layer and a water-blocking glue layer; the water-blocking glue layer specifically comprises the following components: 30-45% of a coating adhesive, 30-50% of water-blocking powder, 10-15% of superabsorbent microspheres, 0.5-1.5% of a non-ionic polyurethane thickening agent and 0.1-0.3% of a silicone defoaming agent. The water-blocking effect of the water-blocking tape is improved by adding superabsorbent microspheres and water-blocking powder in a composite and synergistic manner, and the double-sided water-blocking tape is formed by covering the polyester film, which can prevent the penetration of ointment and ensure the water-blocking performance, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water-blocking tapes, and particularly relates to a double-sided water-blocking tape and a preparation method thereof. BACKGROUND

[0002] The buffer water-blocking tape is also called a water-blocking tape, and is suitable for winding the surface of a power cable conductor and insulation to play a water-blocking role. In recent years, China has increased a large amount of financial and material resources in terms of mileage and operation and maintenance of high-voltage cables. However, cable line faults, especially cable faults, have the ablation phenomenon of water-blocking tapes at the fault position, and therefore, the performance of the water-blocking tape must be researched to reduce the occurrence of cable failure performance.

[0003] The water-blocking tape is an effective auxiliary material for reducing cable failure during use of the cable.

[0004] The water-blocking tape in the prior art is mostly obtained by coating a water-absorbing material on one side of a non-woven fabric, and is a single-sided water-blocking tape, which cannot play a double water-blocking role and the performance needs to be improved. SUMMARY

[0005] The application aims to provide a double-sided water-blocking tape and a preparation method thereof, and solve the above technical problems in the prior art.

[0006] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0007] The technical scheme provided by the application is as follows:

[0008] In the first aspect, the application provides a double-sided water-blocking tape, which comprises a polyester film surface layer, a base material layer and a water-blocking glue layer.

[0009] Preferably, the coating adhesive is an acrylic polymer with a solid content of 35-45% and a viscosity of 2000-5000 mpa.s; the water-blocking powder is a low-crosslinking polyacrylic acid sodium salt with a particle size of 250-300 mesh; and the superabsorbent microspheres have a particle size of 150-200 mesh.

[0010] Preferably, the preparation method of the superabsorbent microspheres comprises the following steps:

[0011] S1: In an N2 atmosphere, acrylamide, acrylic acid, acryloyl morpholine and 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium were dissolved in water, and after adjusting the pH with a sodium hydroxide solution, mixed with the oil phase obtained by mixing Span 80, dihydroxy stearic acid and white oil, stirred and treated, then added ammonium persulfate (APS), sodium bisulfite (SHS) and N,N'-methylene bisacrylamide (MBA), polymerized to obtain a core polymer emulsion;

[0012] In the above process, acrylamide, acrylic acid and acryloyl morpholine, 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium are used as the water phase; white oil, Span 80 and dihydroxy stearic acid are used as the oil phase to form a water-in-oil reverse suspension system, and the water phase undergoes free radical polymerization under the action of the initiator, and the polymerization reaction is limited in the isolated water phase droplets.

[0013] S2: In an N2 atmosphere, acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid were added to water, stirred and treated, then MBA and modified kaolin were added, the pH was adjusted with a NaOH solution, and the core polymer emulsion was added dropwise within 30 min, and stirring was continued, then the initiator APS and SHS were added, and stirring and polymerization were carried out, followed by filtration, drying, sieving to obtain superabsorbent microspheres.

[0014] In the above process, the core surface contains a hydrophobic region from acryloyl morpholine and a small number of hydrophilic points from 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium, as well as physically adsorbed emulsifiers, and the hydrophilic polymer chains grow, anchor and crosslink on the core surface, gradually wrapping the core particles, at the same time, the modified kaolin is also fixed by the crosslinked network and uniformly dispersed in the shell layer; the shell layer can quickly absorb and lock a large amount of water, and the core provides solid mechanical support after the shell layer swells, preventing the microspheres from being crushed or gel blocked under pressure, and maintaining the three-dimensional structure of the swollen body.

[0015] Preferably, in step S1, the concentration of sodium hydroxide is 1 mol / L; the pH value is adjusted to 6-7; the amount ratio of acrylamide, acrylic acid, acryloyl morpholine, 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium, water, Span 80, dihydroxy stearic acid, white oil, APS, SHS, MBA is 180-360 g:30-60 g:20-40 g:10-20 g:320-640 mL:240-480 g:60-120 g:1-2 kg:0.18-0.36 g:0.06-0.12 g:0.36-0.72 g; the stirring treatment conditions are that the stirring treatment speed is 400-500 rpm and the stirring treatment time is 25-35 min; the mixing temperature of the mixed oil phase is 35-45℃; the polymerization conditions are that the polymerization temperature is 40-50℃ and the polymerization time is 3.5-4.5 h.

[0016] Preferably, in the step S2, the amount ratio of acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, water, MBA, modified kaolin, APS, SHS is 15-30 g:9-18 g:6-12 g:150-300 mL:0.3-0.6 g:3-6 g:22.5-50 mg:7.5-15 mg; the stirring treatment time is 30-40 min; the concentration of NaOH solution is 1 mol / L; the adjusted pH value is 6-7; the continued stirring treatment condition is that the continued stirring treatment speed is 350-450 rpm and the continued stirring treatment time is 25-35 min; the stirring polymerization condition is that the stirring polymerization speed is 500-700 rpm, the stirring polymerization time is 1.5-2.2 h and the stirring polymerization temperature is 40-50℃; and the drying temperature is 60-70℃.

[0017] Preferably, the preparation method of the modified kaolin comprises the following steps:

[0018] The nano kaolin is dispersed in anhydrous ethanol, after ultrasonic treatment, 3-(methacryloyloxy) propyl trimethoxysilane (KH-570) solution is added dropwise, acetic acid is used to adjust pH, water bath reflux reaction is carried out, centrifugation, washing, vacuum drying, grinding are carried out, and the modified kaolin is obtained.

[0019] In the above process, the silanol groups generated by the hydrolysis of the silane coupling agent KH-570 and the hydroxyl groups on the surface of the nano kaolin undergo dehydration condensation reaction, and the silane coupling agent containing double bonds is introduced on the surface of the nano kaolin.

[0020] Preferably, the particle size of the modified kaolin is 2-4 μm; the amount ratio of the nano kaolin and anhydrous ethanol is 50-100 g:500-1000 mL; the ultrasonic treatment time is 25-35 min; the concentration of acetic acid is 1 mol / L; the adjusted pH value is 4-5; the water bath reflux reaction condition is that the water bath reflux reaction temperature is 65-75℃ and the water bath reflux reaction time is 5.5-6.5 h; the washing method is that the anhydrous ethanol is washed for 3-5 times; and the vacuum drying temperature is 55-65℃.

[0021] Preferably, the preparation method of the KH-570 solution is that 10-20 g of KH-570 is dissolved in a mixture of 200-400 mL of anhydrous ethanol and 50-100 mL of deionized water to obtain the KH-570 solution.

[0022] In a second aspect, the present application further provides a preparation method of the double-sided water-blocking tape, comprising the following steps:

[0023] Step (1) substrate selection: selecting polyester non-woven fabric;

[0024] Step (2) preparing water-blocking glue: mixing coating adhesive, water-blocking powder, superabsorbent microspheres, non-ionic polyurethane thickening agent and silicone defoaming agent to obtain water-blocking glue;

[0025] Step (3) compounding polyester film and one side of the polyester non-woven fabric by polyamide hot melt adhesive, then roll coating water-blocking glue on the other side of the polyester non-woven fabric, drying, slitting to obtain double-sided water-blocking tape.

[0026] Preferably, in the step (1), the unit area weight of the polyester non-woven fabric is 30-40 g / m².

[0027] Preferably, in the step (3), the dry base coating amount of the double-sided water-blocking tape is 90-110 g / m², the unit area weight is 140-170 g / m², and the thickness is 0.27-0.33 mm; the thickness of the polyester film is 13-18 μm.

[0028] Preferably, in the step (3), the method of compounding the polyester film and one side of the polyester non-woven fabric by polyamide hot melt adhesive is as follows: roll coating polyamide hot melt adhesive on the polyester film at 170-190 ℃, and cooling in a room at room temperature; the dry base coating amount of the hot melt adhesive is 15-20 g / m 2 ; the roll coating line speed is 20-40 m / min; and the drying temperature is 120-180 ℃.

[0029] As described above, due to the adoption of the above technical solutions, the present application has the following advantages:

[0030] 1. The double-sided water-blocking tape prepared by the present application is suitable for wrapping the conductor and insulating surface of power cable to provide double water-blocking effect, and is used for filling the outer surface of the core of optical cable and communication cable with oil paste, and the polyester film is inside, which can prevent the penetration of oil paste and ensure the water-blocking performance.

[0031] 2. The water-blocking tape prepared by the present application is compounded by adding superabsorbent microspheres and water-blocking powder, the core-shell structure can improve the water absorption rate and gel strength, the dense shell layer can improve the thermal stability of the microspheres itself, the acryloyl morpholine in the core material as a hydrophobic rigid monomer can enhance the network strength and thermal stability of the polymer; the modified kaolin improves the compatibility with the polymer and provides physical crosslinking points, improves the gel strength after water absorption, prevents the loss of microspheres dispersion in water, and maintains a high swelling height; the microspheres continuously swell and increase in size, part of the microspheres directly adhere to each other and aggregate into larger volume flocculation, delaying the rupture and release of the internal core layer polymer, and the water-blocking powder is compounded, which synergistically improves the action time and effect of the water-blocking tape.

[0032] 3. The water-blocking tape prepared by the present application reduces the overall charge density of the polymer network by the non-ionic acryloyl morpholine, weakens the Donnan equilibrium effect that causes the hydrogel to shrink in a salt water environment, and the sulfonic acid group from 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium exhibits stronger ion pair dissociation ability than the carboxylate group, reduces the complexation with multivalent cations, reduces the charge shielding effect by the non-ionic acryloyl morpholine and the strong hydration of the sulfonic acid group, and improves the salt resistance of the water-blocking tape. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is a mechanical strength histogram of the double-sided water-blocking tape of the present application;

[0035] Figure 2 is a water absorption performance histogram of the double-sided water-blocking tape of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0037] Some of the substances and sources involved in the following examples and comparative examples are shown in Table 1:

[0038] Table 1

[0039]

[0040] Example 1:

[0041] The present embodiment discloses a preparation method of modified kaolin, comprising the following steps:

[0042] 75 g nanometer kaolin was dispersed in 750 mL anhydrous ethanol, and after ultrasonic treatment for 30 min, a kaolin suspension was obtained; then 15 g KH-570 was dissolved in a mixture of 300 mL anhydrous ethanol and 75 mL deionized water, and after magnetic stirring for 30 min, it was added dropwise into the kaolin suspension, 1 mol / L acetic acid was used to adjust the pH to 4.5, and the reaction was carried out under reflux in a water bath at 70°C for 6 h, centrifugation, washing with anhydrous ethanol 4 times, vacuum drying at 60°C, grinding, to obtain modified kaolin.

[0043] Example 2:

[0044] The embodiment discloses a preparation method of superabsorbent microspheres, comprising the following steps:

[0045] S1: 270 g of acrylamide, 45 g of acrylic acid, 30 g of acryloyl morpholine and 15 g of 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium were dissolved in 480 mL of water, the pH was adjusted to 6.5 with 1 mol / L sodium hydroxide solution, then 320 g of Span 80 and 90 g of dihydroxy stearic acid were added, and 1.5 kg of white oil was added to the obtained oil phase mixture, and stirring was carried out under N2 atmosphere at a speed of 450 rpm for 30 min, then 0.27 g of APS, 0.09 g of SHS and 0.54 g of crosslinking agent MBA were added, and polymerization was carried out at 45°C for 4 h to obtain a core polymer emulsion;

[0046] S2: 22.5 g of acrylamide, 13.5 g of acrylic acid, 9 g of 2-acrylamide-2-methylpropanesulfonic acid were added to 225 mL of water, stirring was carried out for 35 min, then 0.45 g of crosslinking agent MBA and 4.5 g of modified kaolin prepared in Example 1 were added, the pH was adjusted to 6.5 with 1 mol / L NaOH solution, then the core polymer emulsion was added dropwise within 30 min, stirring was carried out under N2 protection at a speed of 400 rpm for 30 min, then 33.8 mg of APS and 11.3 mg of SHS were added, and polymerization was carried out at 45°C under stirring at a speed of 600 rpm for 2 h, filtration, drying at 65°C, and sieving to obtain superabsorbent microspheres.

[0047] Example 3:

[0048] The embodiment discloses a preparation method of superabsorbent microspheres, comprising the following steps:

[0049] S1: 180 g of acrylamide, 60 g of acrylic acid, 20 g of acryloyl morpholine and 20 g of 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt were dissolved in 320 mL of water, the pH was adjusted to 7 with 1 mol / L sodium hydroxide solution, and then mixed with 240 g of Span 80, 120 g of dihydroxy stearic acid and 1 kg of white oil at 45°C to obtain an oil phase, stirred at a speed of 400 rpm under N2 atmosphere for 35 min, then 0.18 g of APS, 0.12 g of SHS and 0.36 g of crosslinking agent MBA were added, and polymerized at 50°C for 3.5 h to obtain a core polymer emulsion;

[0050] S2: 30 g of acrylamide, 9 g of acrylic acid, 12 g of 2-acrylamide-2-methylpropanesulfonic acid were added to 150 mL of water, stirred for 40 min, then 0.3 g of crosslinking agent MBA and 6 g of modified kaolin prepared in Example 1 were added, the pH was adjusted to 6 with 1 mol / L NaOH solution, then the core polymer emulsion was added dropwise within 30 min, stirred at a speed of 450 rpm under N2 protection for 25 min, then 50 mg of initiator APS and 7.5 mg of SHS were added, and polymerized at 50°C at a speed of 500 rpm for 2.2 h, filtered, dried at 60°C, and sieved to obtain superabsorbent microspheres.

[0051] Example 4:

[0052] The embodiment discloses a preparation method of superabsorbent microspheres, comprising the following steps:

[0053] S1: 360 g of acrylamide, 30 g of acrylic acid, 40 g of acryloyl morpholine and 10 g of 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt were dissolved in 640 mL of water, the pH was adjusted to 6 with 1 mol / L sodium hydroxide solution, and then mixed with 480 g of Span 80, 60 g of dihydroxy stearic acid and 2 kg of white oil at 35°C to obtain an oil phase, stirred at a speed of 500 rpm under N2 atmosphere for 25 min, then 0.36 g of APS, 0.06 g of SHS and 0.72 g of crosslinking agent MBA were added, and polymerized at 40°C for 4.5 h to obtain a core polymer emulsion;

[0054] S2: 15 g of acrylamide, 18 g of acrylic acid, 6 g of 2-acrylamide-2-methylpropanesulfonic acid were added into 300 mL of water, stirred and treated for 30 min, then 0.6 g of crosslinking agent MBA and 3 g of modified kaolin prepared in Example 1 were added, the pH was adjusted to 7 with 1 mol / L NaOH solution, then the core polymer emulsion was added dropwise within 30 min, stirred and treated at a speed of 350 rpm under N2 protection for 35 min, then 22.5 mg of initiator APS and 15 mg of SHS were added, and the polymerization was carried out at 40℃ with stirring at a speed of 700 rpm for 1.5 h, then filtered, dried at 70℃, and sieved to obtain super water-absorbing microspheres.

[0055] Example 5:

[0056] The present example discloses a preparation method of a double-sided water-blocking tape, comprising the following steps:

[0057] Step (1) substrate selection: polyester non-woven fabric with a unit area weight of 35 g / m2;

[0058] Step (2) preparation of water-blocking glue: coating adhesive acrylic polymer with a solid content of 40% and a viscosity of 3000 mpa.s 38%, low-crosslinking polyacrylic acid sodium salt 46%, super water-absorbing microspheres prepared in Example 2 14.8%, non-ionic polyurethane thickening agent 1%, and silicone defoaming agent 0.2%;

[0059] Step (3) composite the polyester film with one side of the polyester non-woven fabric by polyamide hot melt adhesive, roll coat the water-blocking glue on the other side of the polyester non-woven fabric, the line speed is 30 m / min, dry at 150℃, and cut to obtain the double-sided water-blocking tape.

[0060] The particle size of the low-crosslinking polyacrylic acid sodium salt is 260 mesh; the particle size of the super water-absorbing microspheres is 170 mesh.

[0061] The dry base coating amount of the double-sided water-blocking tape is 100 g / m 2 ; the thickness of the polyester film is 15 μm.

[0062] The method of composite the polyester film with one side of the polyester non-woven fabric by polyamide hot melt adhesive: roll coat the polyamide hot melt adhesive on the polyester film at 180℃, and obtain the polyester composite non-woven fabric after cooling; the dry base coating amount is 17 g / m 2 .

[0063] Example 6:

[0064] The present example discloses a preparation method of a double-sided water-blocking tape, comprising the following steps:

[0065] Step (1) substrate selection: polyester non-woven fabric with a unit area weight of 30 g / m 2 ;

[0066] Step (2) Preparation of water-blocking glue: solid content 45%, viscosity 5000 mpa.s coating adhesive acrylic polymer 35%, water-blocking powder low cross-linked polyacrylic acid sodium salt 48.5%, super absorbent microspheres prepared in Example 3 15%, non-ionic polyurethane thickening agent 1.3%, silicone defoaming agent 0.2%;

[0067] Step (3) After the polyester film and the side of the polyester non-woven fabric are compounded by polyamide hot melt adhesive, the water-blocking glue is roll-coated on the other side of the polyester non-woven fabric, the linear speed is 20 m / min, and the polyester non-woven fabric is dried at 180°C, and then cut to obtain a double-sided water-blocking tape.

[0068] The particle size of the low cross-linked polyacrylic acid sodium salt is 250 mesh; and the particle size of the super absorbent microspheres is 200 mesh.

[0069] The dry basis coating amount of the double-sided water-blocking tape is 90 g / m 2 ; and the thickness of the polyester film is 18 μm.

[0070] The method for compounding the polyester film and the side of the polyester non-woven fabric by polyamide hot melt adhesive is as follows: the polyamide hot melt adhesive is roll-coated on the polyester film at 190°C, and the polyester composite non-woven fabric is obtained after cooling; and the dry basis coating amount is 20 g / m 2 .

[0071] Example 7:

[0072] The embodiment discloses a preparation method of a double-sided water-blocking tape, which comprises the following steps:

[0073] Step (1) The base material is selected as a polyester non-woven fabric with a unit area weight of 40 g / m 2 ;

[0074] Step (2) Preparation of water-blocking glue: solid content 35%, viscosity 2000 mpa.s coating adhesive acrylic polymer 45%, water-blocking powder low cross-linked polyacrylic acid sodium salt 43.9%, super absorbent microspheres prepared in Example 4 10%, non-ionic polyurethane thickening agent 0.8%, silicone defoaming agent 0.3%;

[0075] Step (3) After the polyester film and the side of the polyester non-woven fabric are compounded by polyamide hot melt adhesive, the water-blocking glue is roll-coated on the other side of the polyester non-woven fabric, the linear speed is 30 m / min, and the polyester non-woven fabric is dried at 120°C, and then cut to obtain a double-sided water-blocking tape.

[0076] The particle size of the low cross-linked polyacrylic acid sodium salt is 300 mesh; and the particle size of the super absorbent microspheres is 150 mesh.

[0077] The dry basis coating amount of the double-sided water-blocking tape is 110 g / m 2 ; and the thickness of the polyester film is 13 μm.

[0078] Polyester film and one side of polyester non-woven fabric were compounded by polyamide hot melt adhesive method: at 170℃, polyamide hot melt adhesive was coated on the polyester film, and polyester composite non-woven fabric was obtained after cooling; the dry base coating amount was 15g / m 2 .

[0079] Comparative Example 1:

[0080] Comparative Example 1 and Example 5, in the process of preparing the double-sided water-blocking tape, no superabsorbent microspheres were added, and other conditions were unchanged.

[0081] Comparative Example 2:

[0082] Comparative Example 2 and Example 5, in the process of preparing the double-sided water-blocking tape, no S2 was added when preparing the superabsorbent microspheres in Example 2, and other conditions were unchanged. The specific steps are as follows: 270g acrylamide, 45g acrylic acid, 30g acryloyl morpholine and 15g 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium were dissolved in 480mL water, the pH was adjusted to 6.5 with 1mol / L sodium hydroxide solution, then 320g Span 80 and 90g dihydroxystearic acid were added to the oil phase obtained by dissolving 1.5kg white oil at 40℃, and stirred at 450rpm for 30min under N2 atmosphere, then 0.27g APS, 0.09g SHS and 0.54g crosslinking agent MBA were added, and polymerized at 45℃ for 4h, filtered, dried and ground to obtain high water-absorbing resin powder; the high water-absorbing resin powder was used to replace the superabsorbent microspheres in an equal amount.

[0083] Comparative Example 3:

[0084] Comparative Example 3 and Example 5, in the process of preparing the double-sided water-blocking tape, no acryloyl morpholine was added when preparing the superabsorbent microspheres in Example 2, and other conditions were unchanged.

[0085] Comparative Example 4:

[0086] Comparative Example 4 and Example 5, in the process of preparing the double-sided water-blocking tape, in the process of preparing the superabsorbent microspheres in Example 2, 2-acrylamide-2-methylpropanesulfonic acid was used to replace 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium in an equal amount, and other conditions were unchanged.

[0087] Comparative Example 5:

[0088] Comparative Example 5 and Example 5, in the process of preparing the double-sided water-blocking tape, no modified kaolin was added when preparing the superabsorbent microspheres in Example 2, and other conditions were unchanged.

[0089] Comparative Example 6:

[0090] Comparative Example 6 is compared with Example 5, in the process of preparing the double-sided water-blocking tape, the modified kaolin is completely replaced by unmodified kaolin when preparing the superabsorbent microspheres of Example 2, and other conditions are unchanged.

[0091] The properties of the double-sided water-blocking tapes prepared from Examples 5-7 and Comparative Examples 1-6 are tested.

[0092] Basic performance test method:

[0093] The expansion height and expansion rate test is tested by the method in Appendix C of JB / T10259—2014 "Water-blocking tape for cables and optical cables", and 150 mL of water is selected as the reference; the tensile test is tested according to the method in GB / T24218.3—2010 "Textiles - Test methods for nonwovens - Part 3: Determination of tensile strength and elongation at break", and the test environment needs to meet the temperature and humidity requirements in GB / T2941—2006; the water content is tested by the oven method, dried at 105℃ to constant weight; the maximum water absorption of the water-blocking tape is tested in 0.1 mol / L sodium chloride solution, and the short-term stability and long-term stability tests are carried out in a heat aging oven, and the test results are shown in Table 2.

[0094] Table 2

[0095]

[0096] According to Table 2 and from Examples 5-7 and Comparative Examples 1-6, the double-sided water-blocking tape prepared from Example 5 has good mechanical properties, water-blocking properties and stability. As shown by the comparison of Comparative Examples 1-4 and Examples 5-7, the double-sided water-blocking tape obtained by adding the superabsorbent microspheres prepared by the method of the present application can improve the water-blocking properties and stability, and the performance of the double-sided water-blocking tape obtained by the method of the present application is the best, and the effect is not as obvious as the method of the present application; as shown by Comparative Examples 5-6 and Examples 5-7, the addition of modified kaolin can improve the performance of the double-sided water-blocking tape.

[0097] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent substitutions or changes within the technical scope disclosed by the present application according to the technical solution and inventive concept of the present application, which should be covered within the protection scope of the present application.

[0098] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application and its practical application to those skilled in the art and to enable those skilled in the art to utilize the application in its best mode. The application is only limited by the claims and their full scope and equivalents.

Claims

1. A double-sided water-blocking strip, characterized in that, The double-sided water-blocking tape comprises a polyester film layer, a substrate layer, and a water-blocking adhesive layer; the water-blocking adhesive layer specifically comprises the following components: 30-45% coating adhesive, 30-50% water-blocking powder, 10-15% superabsorbent microspheres, 0.5-1.5% nonionic polyurethane thickener, and 0.1-0.3% silicone defoamer; The preparation method of the superabsorbent microspheres includes the following steps: S1: In a N2 atmosphere, acrylamide, acrylic acid, acrylmorpholine and sodium 3-allyloxy-2-hydroxy-1-propanesulfonate are dissolved in water. After adjusting the pH with sodium hydroxide solution, the mixture is mixed with the oil phase obtained by mixing Span 80, dihydroxystearic acid and white oil. The mixture is stirred and treated. Then APS, SHS and MBA are added and polymerized to obtain the core polymer emulsion. S2: In a nitrogen atmosphere, acrylamide, acrylic acid, and 2-acrylamide-2-methylpropanesulfonic acid are added to water and stirred. Then, MBA and modified kaolin are added. After adjusting the pH with NaOH solution, the mixture is added dropwise to the core polymer emulsion within 30 minutes. Stirring continues, and then initiators APS and SHS are added. The mixture is stirred and polymerized, filtered, dried, and sieved to obtain superabsorbent microspheres.

2. The double-sided water-blocking strip according to claim 1, characterized in that, The coating adhesive is an acrylic polymer with a solid content of 35-45% and a viscosity of 2000-5000 mPa·s; the water-blocking powder is a low-crosslinked sodium polyacrylate with a particle size of 250-300 mesh; and the superabsorbent microspheres have a particle size of 150-200 mesh.

3. The double-sided water-blocking strip according to claim 1, characterized in that, In step S1, the ratio of acrylamide, acrylic acid, acrylmorpholine, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, water, Span 80, dihydroxystearic acid, white oil, APS, SHS, and MBA is 180-360g:30-60g:20-40g:10-20g:320-640mL:240-480g:60-120g:1-2kg:0.18-0.36g:0.06-0.12g:0.36-0.72g; the concentration of sodium hydroxide is 1mol / L; the pH is adjusted to 6-7; the stirring conditions are: stirring speed 400-500rpm, stirring time 25-35min; the mixing temperature of the resulting oil phase is 35-45℃; the polymerization conditions are: polymerization temperature 40-50℃, polymerization time 3.5-4.5h.

4. The double-sided water-blocking strip according to claim 1, characterized in that, In step S2, the ratio of acrylamide, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid, water, MBA, modified kaolin, APS, and SHS is 15-30g:9-18g:6-12g:150-300mL:0.3-0.6g:3-6g:22.5-50mg:7.5-15mg; the stirring time is 30-40min; the NaOH solution concentration is 1mol / L; the pH is adjusted to 6-7; the stirring conditions are: stirring speed 350-450rpm, stirring time 25-35min; the polymerization conditions are: polymerization speed 500-700rpm, polymerization time 1.5-2.2h, polymerization temperature 40-50℃; and the drying temperature is 60-70℃.

5. The double-sided water-blocking strip according to claim 1, characterized in that, The method for preparing the modified kaolin includes the following steps: Nano-kaolin was dispersed in anhydrous ethanol, ultrasonically treated, and then KH-570 solution was added dropwise. The pH was adjusted with acetic acid, and the reaction was carried out under reflux in a water bath. After centrifugation, washing, vacuum drying, and grinding, modified kaolin was obtained.

6. The double-sided water-blocking strip according to claim 5, characterized in that, The modified kaolin has a particle size of 2-4 μm; the ratio of nano-kaolin to anhydrous ethanol is 50-100 g: 500-1000 mL; the ultrasonic treatment time is 25-35 min; the acetic acid concentration is 1 mol / L; the pH value is adjusted to 4-5; the water bath reflux reaction conditions are: water bath reflux reaction temperature is 65-75℃, and water bath reflux reaction time is 5.5-6.5 h; the washing method is: washing with anhydrous ethanol 3-5 times; the vacuum drying temperature is 55-65℃; the KH-570 solution is prepared by dissolving 10-20 g of KH-570 in a mixture of 200-400 mL of anhydrous ethanol and 50-100 mL of deionized water to obtain the KH-570 solution.

7. A method for preparing a double-sided water-blocking tape according to any one of claims 1-6, characterized in that, Includes the following steps: Step (1) Substrate selection: Select polyester nonwoven fabric; Step (2) Preparation of water-blocking adhesive: Mix the coating adhesive, water-blocking powder, superabsorbent microspheres, nonionic polyurethane thickener, and silicone defoamer to obtain water-blocking adhesive; Step (3) After laminating the polyester film with one side of the polyester nonwoven fabric using polyamide hot melt adhesive, apply water-blocking adhesive to the other side of the polyester nonwoven fabric, dry, and cut to obtain a double-sided water-blocking tape.

8. The method for preparing the double-sided water-blocking tape according to claim 7, characterized in that, In step (1), the unit area weight of the polyester nonwoven fabric is 30-40 g / m². 2 In step (3), the dry coating amount of the double-sided water-blocking tape is 90-110 g / m², the unit area weight is 140-170 g / m², and the thickness is 0.27-0.33 mm; the thickness of the polyester film is 13-18 μm.

9. The method for preparing the double-sided water-blocking tape according to claim 7, characterized in that, In step (3), the polyester film is bonded to one side of the polyester nonwoven fabric using polyamide hot melt adhesive: the polyamide hot melt adhesive is roller-coated onto the polyester film at 170-190℃, and cooled to room temperature; the dry coating amount of the hot melt adhesive is 15-20 g / m². 2 The roller coating speed is 20-40 m / min; the drying temperature is 120-180℃.

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