Anti-drying and waterproof raw material belt and preparation method thereof

Abstract

The invention relates to an anti-dry waterproof raw material belt and a preparation method thereof. The raw material belt comprises a supporting layer and an anti-dry bentonite waterproof layer arranged on one side of the supporting layer. The preparation method comprises the following steps: step 1, material hanging: uniformly hanging bentonite waterproof coating on one side of a supporting layer, and then heating and drying to form a bentonite waterproof layer, so as to obtain a semi-finished raw material belt; and 2, anti-dry protection liquid is applied, specifically, the anti-dry protection liquid is applied to the surface of the bentonite waterproof layer, the bentonite waterproof layer absorbs the anti-dry protection liquid, and an anti-dry protection film layer is formed on the surface of the bentonite waterproof layer, so that the anti-dry bentonite waterproof layer is formed, and the anti-dry waterproof raw material belt is prepared. Even if being exposed in the air for a long time and losing moisture, the sealing agent still forms a plastic paste, does not become dry and solid, can be used for sealing water pipelines, and can also be used for sealing gas pipelines.

Description

Technical Field

[0001] The invention belongs to the technical field of raw tapes, and in particular relates to a dry-proof and waterproof raw tape and a preparation method thereof. Background Art

[0002] Raw tape is a commonly used auxiliary product in pipeline installation. It is used at the joints of pipe fittings to enhance the airtightness of pipeline joints. Traditional raw tape is usually made of resin materials such as PEFT or PE, which are extruded into a paste and then calendered. It has the following disadvantages: 1) It is easy to age, especially in a humid environment, where aging is particularly serious; 2) It has limited chemical resistance; 3) It has many winding layers when used; 4) It has a complex production process, the material is non-degradable, and there is a certain degree of environmental pollution; 4) It cannot be reused; 5) It does not have a water hygiene approval number, and there is uncertainty about its use in drinking water.

[0003] In order to solve the above problems, our company has tried to use non-woven fabrics as materials, and coated the non-woven fabrics with bentonite waterproof coating to make raw tapes. The performance of bentonite swelling when it meets water is used to seal pipelines. Compared with the traditional raw tapes prepared by extrusion and calendering of resin materials, it has the advantages of simple production process, non-toxicity, environmental protection, biodegradability, high safety factor, reusability, and can be used for drinking water pipelines; however, although toughening agents and crack inhibitors are added to the bentonite waterproof coating, they can only reduce the degree of shrinkage cracks, and it will still produce fine cracks due to shrinkage. Therefore, it can only be used for sealing water pipelines, not gas pipelines. In addition, the raw tape coating sealed in the thread of the pipe fittings will also produce fine cracks after the pipeline stops conveying water for a long time. When water is conveyed again, there will be leakage in the early stage. Only after 2 hours after the water is conveyed, the bentonite coating of the raw tape fully absorbs water and expands, and the penetration phenomenon will be prevented, which brings great inconvenience to its use. In addition, before use, it needs to be dipped in water to allow the bentonite to absorb moisture before construction, so there is also the problem of inconvenient operation. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a dry-proof and waterproof raw tape and a preparation method thereof. Even if the tape is exposed to dry air for a long time and loses water, it will not shrink or crack. It can be used not only for sealing water pipes, but also for sealing gas pipes.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A desiccation-proof and waterproof raw material tape comprises: a support layer and an desiccation-proof bentonite waterproof layer arranged on one side of the support layer.

[0007] As a further technical solution, the support layer is a non-woven fabric layer;

[0008] As a further technical solution, the anti-drying bentonite waterproof layer is prepared by applying an anti-drying protection liquid on the bentonite waterproof layer; the anti-drying protection liquid penetrates into the bentonite waterproof coating layer and forms an anti-drying protection film layer on the surface of the bentonite waterproof layer;

[0009] As a further technical solution, the bentonite waterproof layer is prepared by using bentonite waterproof coating.

[0010] A method for preparing a dry and waterproof raw tape comprises the following steps:

[0011] Step 1, hanging material: evenly hang the bentonite waterproof coating on one side or both sides of the support layer, and then heat and dry it to form a bentonite waterproof layer to obtain a semi-finished raw tape;

[0012] Step 2, applying anti-drying protection liquid: applying anti-drying protection liquid on the surface of bentonite waterproof layer, the bentonite waterproof layer absorbs the anti-drying protection liquid, the anti-drying protection liquid penetrates into the bentonite waterproof layer and forms an anti-drying protection film layer on the surface of the bentonite waterproof layer, thereby forming an anti-drying bentonite waterproof layer, and preparing the anti-drying waterproof raw tape.

[0013] As a further technical solution, in step 2, before applying the anti-drying protective liquid, the semi-finished raw tape needs to be divided into strips; after the anti-drying protective film layer is formed, the anti-drying and waterproof raw tape needs to be wound into a roll, packaged and sealed.

[0014] As a further technical solution, the anti-drying protection liquid is applied by spraying or dipping;

[0015] As a further technical solution, the temperature of the anti-drying protection liquid is ≥40°C.

[0016] As a further technical solution, the bentonite waterproof coating comprises the following raw materials in percentage by weight:

[0017] Bentonite 40-60%; crack inhibitor 1-3%; toughening agent 3-8%, other additives 0-5%, water 29-54%.

[0018] As a further technical solution, the crack inhibitor is nanocellulose;

[0019] As a further technical solution, the toughening agent is a water-based polyurethane emulsion;

[0020] As a further technical solution, other additives include one or more of anti-aging agents, ultraviolet absorbers, antioxidants, inorganic nanomaterials, and film-forming agents.

[0021] As a further technical solution, the preparation method of the bentonite waterproof coating comprises:

[0022] Firstly, a film former and a toughening agent are added into water, and other additives are selectively added, and ultrasonic dispersion is performed to obtain an additive solution;

[0023] Then, the bentonite is sent to the mixer through a closed conveyor belt, the auxiliary solution is added, and the mixture is stirred for 3-5 minutes to obtain the bentonite waterproof coating.

[0024] As a further technical solution, the anti-drying protective film layer is prepared from an anti-drying protective liquid, and the anti-drying protective liquid includes the following raw materials in percentage by weight:

[0025] Surfactant 40-60%;

[0026] Mineral oil 10-20%;

[0027] Water 30-50%.

[0028] The surfactant has hydrophilic and lipophilic groups.

[0029] As a further technical solution, the surfactant is alkylphenol polyoxyethylene ether.

[0030] As a further technical solution, the mineral oil is white oil.

[0031] As a further technical solution, the preparation method of the anti-drying protection liquid includes: first mixing water and alkylphenol polyoxyethylene ether, heating to 50°C to 70°C, stirring to form a uniform liquid, then adding white oil, using a homogenizer, homogenizing at a speed of 7000 rpm for 10 minutes to obtain the anti-drying protection liquid.

[0032] As a further technical solution, the bentonite is sodium-based bentonite, the particle size of the bentonite is -44 microns, and the viscosity is greater than or equal to 50mpa.s.

[0033] As a further technical solution, the non-woven fabric is polyester spunbond hot-pressed non-woven fabric.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. Bentonite is a silicate clay mineral with montmorillonite as the main component. Its special layered structure gives it excellent hydrophilicity, plasticity, expansibility, adhesion, rheology and thickening properties. After the bentonite particles swell in water, they can form a uniform colloidal system. This process fills the bentonite layer with water, forming a continuous and tight water film barrier, thereby preventing further penetration of water and achieving the effect of blocking water seepage. In addition, its rheology, expansibility and plasticity also give bentonite the self-repairing properties, so that it can fill gaps, improve the waterproof effect, and extend the service life of the raw tape; and the present invention uses bentonite as a waterproof and anti-leakage agent, hangs it on a non-woven fabric, and makes a raw tape. Compared with the traditional PFTE raw tape, it uses natural inorganic materials for waterproofing and anti-leakage, has the characteristics of anti-aging and corrosion resistance, and has a long service life. In addition, it also has the advantages of simple production process, safety and environmental protection, and can be applied to drinking water pipelines.

[0036] 2. Bentonite can only exert its waterproof and anti-leakage performance in a humid environment after absorbing water and swelling. When it is exposed to dry air, water molecules will be lost, causing the bentonite waterproof layer to shrink and produce large cracks, and even cause the bentonite waterproof layer to fall off, thereby affecting the waterproof and anti-seepage performance of the raw tape. In order to solve this problem, the present invention adds polyurethane and nanocellulose to the bentonite waterproof coating, uses polyurethane to improve the toughness of the bentonite waterproof layer, and uses nanocellulose to improve the adhesion and film-forming properties of the bentonite waterproof coating, and to prevent it from cracking to a certain extent. However, even though the addition of polyurethane and nanocellulose improves its large cracks and falling off to a certain extent, , when it is exposed to the air, it will still produce tiny cracks due to shrinkage; and to solve this problem, the present invention immerses the bentonite waterproof layer in an anti-drying protective liquid after it is dried. On the one hand, it can form an oil film on the surface of the anti-drying protective layer to prevent the evaporation of water. On the other hand, the anti-drying protective liquid can also penetrate into the pores and tiny cracks formed by the shrinkage of the bentonite waterproof layer, seal its pores and cracks, and combine the layer structure into a whole, so that the entire coating of the raw tape is in a plastic paste state. Even in the case of water loss, it will not dry up, so that it can be used for the sealing of gas pipelines. Moreover, since it will not dry up, it can be used directly. Compared with the raw tape with a separate bentonite waterproof layer, it does not need to be dipped in water before use.

[0037] 3. Although adding oily substances such as white oil to bentonite waterproof coating can prevent the dehydration of bentonite to a certain extent, the addition of oily substances will reduce the adhesion of the bentonite waterproof layer, resulting in poor adhesion of the bentonite waterproof coating on the non-woven fabric support layer, thereby increasing the risk of the bentonite waterproof coating falling off, which not only increases the difficulty of its production and processing, but also affects its use. The present invention selects and optimizes the formula of the anti-drying protection liquid, and determines the formula of the anti-drying protection liquid composed of water, alkylphenol polyoxyethylene ether and white oil, wherein the alkylphenol polyoxyethylene ether (OP-10) is a hydrophilic group and a lipophilic group. The surfactant, when mixed with water and oil, the lipophilic group faces the oil molecule side and is connected by intermolecular force, while the hydrophilic group faces the water molecule side and is also connected by molecular force. Under the action of high-speed stirring, a water-in-oil continuous phase white suspension emulsion is formed. After the emulsion comes into contact with the bentonite waterproof layer on the surface of the raw material belt, most of the water is absorbed by the bentonite, thereby forming an anti-drying protective film with alkylphenol polyoxyethylene and white oil as main components on the outer surface and pore structure surface of the bentonite waterproof layer, which can ensure the uniform distribution of the anti-drying protective liquid on the bentonite waterproof layer, and will not affect the adhesion of the anti-drying bentonite waterproof layer on the supporting layer.

[0038] In summary, the present invention adopts bentonite as a waterproofing agent, which is mounted on a non-woven fabric to prepare a raw tape, and nanocellulose and polyurethane are added to the bentonite waterproof coating to prevent it from forming large cracks and falling off problems. By applying an anti-drying protective liquid on the surface of the bentonite waterproof layer, it is ensured that the anti-drying bentonite waterproof layer is always in a plastic paste state even when it loses water, and does not dry out. It can be used not only for sealing liquid pipelines but also for sealing gas pipelines. Compared with traditional bentonite waterproof raw tapes, it does not require dipping in water before use. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0041] In an embodiment of the present invention,

[0042] Polyester spunbond hot-pressed non-woven fabric: gram weight 28.5g / m2, width 0.545 / 0.56m, longitudinal breaking strength 111N / 5cm, transverse breaking strength 35N / 5cm, longitudinal elongation at break 19%, transverse elongation at break 20%, longitudinal tear strength 20N, transverse tear strength 7N, heat shrinkage 1.9 / 2.15%, thickness 0.18mm, air permeability 3188mm / s; purchased from Wenzhou Ye Di Packaging Co., Ltd.

[0043] Sodium bentonite: particle size -44 microns, gel value 17ml; expansion volume 30ml, viscosity ≥50mpa.s, drying loss 13%, purchased from Shijiazhuang Langzhong New Material Technology Co., Ltd.;

[0044] The nanocellulose adopts carboxyl modified cellulose nanocrystals, with a fiber diameter of 4 to 10 nm and a length of 100 to 500 nm; it is purchased from Nanjing Tianlu Nanotechnology Co., Ltd.

[0045] Alkylphenol polyoxyethylene ether (OP-10) was purchased from Zhengzhou Renming Chemical Products Co., Ltd.;

[0046] 46# white oil (99.5% concentration), purchased from Suzhou Hesen Special Oil Co., Ltd.;

[0047] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0048] Embodiment 1:

[0049] A method for preparing a dry and waterproof raw tape comprises the following steps:

[0050] Step 1: Liquid preparation:

[0051] A: Preparation of bentonite waterproof coating:

[0052] formula:

[0053] Bentonite: 50%, nanocellulose 2.5%; water-based polyurethane emulsion: 5%, other additives: 1%, water: balance;

[0054] Method: First, nanocellulose, antioxidant and aqueous polyurethane emulsion are added into water and dispersed uniformly by ultrasonication to obtain an additive solution;

[0055] The bentonite is sent to the mixer through a closed conveyor belt, the auxiliary solution is added, and the mixture is stirred for 3-5 minutes to obtain the bentonite waterproof coating.

[0056] B: Preparation of anti-drying protection liquid (prepared before use):

[0057] Formula: 50% alkylphenol polyoxyethylene ether; 15% white oil; 35% water.

[0058] Method: First mix water and alkylphenol polyoxyethylene ether, heat to 60°C, stir to make a uniform liquid, then add white oil, use a homogenizer, stir at a speed of 7000 rpm for 10 minutes to obtain the anti-drying protection liquid.

[0059] Step 2: Hanging:

[0060] The bentonite waterproof coating is evenly hung on one side of the non-woven fabric using a fully automatic hanging machine (commercially purchased equipment), and then heated and dried to a moisture content of ≤5% to form a bentonite waterproof layer to obtain a semi-finished raw tape;

[0061] Step 3, slitting, applying waterproof protection liquid, winding, and sealing bags: After the semi-finished raw tape is slid, the bentonite waterproof layer is immersed in an anti-drying protection liquid at a temperature of 40 degrees Celsius, so that the anti-drying protection liquid penetrates into the pores and gaps of the bentonite waterproof layer, and forms an anti-drying protection film layer on the surface of the bentonite waterproof layer, thereby forming an anti-drying bentonite waterproof layer, which is then wound into a roll and sealed in a bag to obtain an anti-drying waterproof raw tape.

[0062] The bentonite waterproof raw tape prepared in this embodiment includes a non-woven fabric layer, and an anti-drying bentonite waterproof layer arranged on one side of the non-woven fabric layer (the anti-drying protection liquid penetrates into the bentonite waterproof layer, making the two become a whole, and the anti-drying bentonite waterproof layer has no obvious layer structure separation), and the thickness of the anti-drying bentonite waterproof layer is 0.5 mm.

[0063] Example 2

[0064] A method for preparing a dry and waterproof raw tape comprises the following steps:

[0065] Step 1: Liquid preparation:

[0066] A: Preparation of bentonite waterproof coating:

[0067] formula:

[0068] Bentonite: 50%, Nanocellulose: 2.0%; Waterborne polyurethane emulsion: 3%; Other additives: 1%; Water: the balance;

[0069] Method: Same as Example 1;

[0070] B: Preparation of anti-drying protection liquid (prepared before use):

[0071] Formula: Alkylphenol polyoxyethylene ether: 55%; White oil: 10%; Water: the balance.

[0072] Method: Same as Example 1.

[0073] Step 2, hanging material: same as in the embodiment;

[0074] Step 3, stripping, applying waterproof protective liquid, winding, and bagging: the same as in Example 1.

[0075] The anti-drying waterproof raw tape prepared in this embodiment includes a non-woven fabric layer and an anti-drying bentonite waterproof layer arranged on one side of the non-woven fabric layer (the anti-drying protective liquid penetrates into the bentonite waterproof layer, making the two become a whole, and the anti-drying bentonite waterproof layer has no obvious layer structure separation), and the thickness of the anti-drying bentonite waterproof layer is 0.5 mm.

[0076] Example 3

[0077] A method for preparing a dry and waterproof raw tape comprises the following steps:

[0078] Step 1: Liquid preparation:

[0079] A: Preparation of bentonite waterproof coating:

[0080] Formula: bentonite: 50%, nanocellulose: 3.0%; water-based polyurethane emulsion: 6%; other additives: 1%; water balance;

[0081] Method: Same as Example 1.

[0082] B: Preparation of anti-drying protection liquid (prepared before use):

[0083] Formula: 45% alkylphenol polyoxyethylene ether; 20% white oil; the balance is water.

[0084] Method: Same as Example 1.

[0085] Step 2, hanging material: same as in Example 1;

[0086] Step 3, stripping, applying waterproof protective liquid, winding, and bagging: the same as in Example 1.

[0087] The anti-drying waterproof raw tape prepared in this embodiment includes a non-woven fabric layer and an anti-drying bentonite waterproof layer arranged on at least one side of the non-woven fabric layer (the anti-drying protective liquid penetrates into the bentonite waterproof layer, so that the two become a whole, and the anti-drying bentonite waterproof layer has no obvious layer structure separation). The thickness of the anti-drying bentonite waterproof layer in this embodiment is 0.5 mm.

[0088] Comparative Example 1

[0089] A method for preparing an anti-drying and waterproof raw tape comprises the following steps: the same as Example 1, except that the anti-drying protection liquid formula does not contain white oil, and the concentration of alkylphenol polyoxyethylene ether is replaced by 65% ​​from 50% in Example 1;

[0090] A dry-proof waterproof raw tape comprises a non-woven fabric layer and an dry-proof bentonite waterproof layer arranged on at least one side of the non-woven fabric layer (the dry-proof protective liquid penetrates into the bentonite waterproof layer so that the two become a whole, and the dry-proof bentonite waterproof layer has no obvious layer structure separation). The thickness of the dry-proof bentonite waterproof layer in this embodiment is 0.5 mm.

[0091] Comparative Example 2

[0092] A method for preparing an anti-drying and waterproof raw tape comprises the following steps: the same as embodiment 1, except that the anti-drying protection liquid and step 3 are different;

[0093] In Comparative Example 2, the anti-drying protection liquid is prepared by mixing white oil and alkylphenol polyoxyethylene ether in a mass ratio of 10:3, and does not contain water.

[0094] Step 3, slitting, soaking, applying anti-drying protection liquid, winding into rolls, and sealing bags: slitting the semi-finished raw tape, and then soaking it in 40 degrees Celsius pure water for 20 seconds to allow the bentonite waterproof layer to fully absorb water, soaking it in 40 degrees Celsius anti-drying protection liquid, taking it out to form an anti-drying protection film layer, and then winding it into a roll, sealing it in a bag, and obtaining the anti-drying waterproof raw tape.

[0095] A waterproof raw material tape comprises a non-woven fabric layer and an anti-drying bentonite waterproof layer arranged on at least one side of the non-woven fabric layer. The thickness of the anti-drying bentonite waterproof layer in this embodiment is 0.5 mm. The anti-drying bentonite waterproof layer comprises a bentonite waterproof layer and an anti-drying protective film arranged on the surface of the bentonite waterproof layer. The bentonite waterproof layer and the anti-drying protective film layer have obvious layer separation phenomenon.

[0096] Comparative Example 3

[0097] A method for preparing a waterproof raw tape comprises the following steps:

[0098] Step 1: Liquid preparation:

[0099] A: Preparation of bentonite waterproof coating: same as in Example 1;

[0100] Step 2, hanging material: same as in Example 1;

[0101] Step 3, stripping, winding, soaking, bagging, and aging: After the semi-finished raw tape is stripped and wound into a roll, it is immersed in pure water greater than 40 degrees Celsius for 20 seconds, sealed and aged for 10 days to allow the bentonite waterproof layer to fully absorb moisture to obtain a waterproof raw tape.

[0102] The waterproof raw tape prepared in this comparative example includes a non-woven fabric layer and a bentonite waterproof layer disposed on one side of the non-woven fabric layer, and the bentonite waterproof layer has a thickness of 0.5 mm.

[0103] Comparative Example 4

[0104] A method for preparing a waterproof raw tape is the same as that of comparative example 3, except that nanocellulose and aqueous polyurethane emulsion are not added.

[0105] The waterproof raw tape prepared in this comparative example includes a non-woven fabric layer and a bentonite waterproof layer disposed on one side of the non-woven fabric layer, and the bentonite waterproof layer has a thickness of 0.5 mm.

[0106] Bentonite: 50%, nanocellulose 2.5%; water-based polyurethane emulsion: 5%, other additives: 1%, water: balance;

[0107] Comparative Example 5

[0108] A method for preparing a dry and waterproof raw tape comprises the following steps:

[0109] Step 1: Prepare anti-drying bentonite waterproof coating:

[0110] Formula: bentonite: 40%, nanocellulose 2.0%; water-based polyurethane emulsion: 4%, other additives: 0.8%, alkylphenol polyoxyethylene ether 10%; white oil: 3%; water: balance;

[0111] Method: First, nanocellulose, antioxidant, and aqueous polyurethane emulsion are added to part of water and uniformly dispersed by ultrasonication to obtain an additive solution; then, bentonite is sent to a mixer through a closed conveyor belt, the additive solution is added, and stirred for 3-5 minutes to obtain a mixture A;

[0112] Then, water and alkylphenol polyoxyethylene ether were mixed, heated to 60° C., stirred to form a uniform liquid, and white oil was added, and homogenized at a speed of 7000 rpm for 10 minutes using a homogenizer to obtain a B mixture;

[0113] Finally, the A mixture and the B mixture were mixed at 60°C and stirred for 10 minutes until uniform, thereby obtaining a dry-proof bentonite waterproof coating.

[0114] Step 2, hanging material: using a fully automatic hanging material machine (commercially purchased equipment) to evenly hang the bentonite waterproof coating on one side of the non-woven fabric, and then heating and drying it to a moisture content of ≤5% to form an anti-drying bentonite waterproof layer to obtain a semi-finished raw tape;

[0115] After drying, the semi-finished raw material tape becomes paste-like and cannot be subsequently stripped. In addition, the anti-drying bentonite waterproof layer has poor adhesion on the non-woven fabric and always falls off, making subsequent winding operations impossible.

[0116] Effect example 1: Water loss time of anti-drying bentonite waterproofing layer and coating condition after water loss

[0117] 1. After unpacking, the raw tapes prepared in each embodiment and comparative examples 1-4 were placed in a 25°C 15% humidity environment for several days, and the surface condition of the coating was observed. The surface condition was observed every 2 hours on the first day and once a day thereafter. The time when the coating was dry or cracked was recorded. The results are shown in Table 1.

[0118] Table 1

[0119]

[0120]

[0121] Effect example 2: Sealing effect detection

[0122] 1. Pressure-bearing and sealing conditions of water pipes

[0123] The anti-drying and waterproof raw tape prepared in Example 1 was subjected to sealing pressure detection and compressed gas sealing detection. The water pipeline sealing pressure detection method is as follows: during the test, the number of windings is 3 layers, at 32.8 degrees Celsius, the air in the test pipeline is exhausted, and then water is injected. The test is carried out for 36 hours using 20 kg and 25 kg pressure values, respectively, and the pressure drop and leakage are observed. The results are shown in Table 2;

[0124] Table 2: Pressure-bearing conditions of bentonite waterproof raw tape when sealing water pipes in Example 1

[0125]

[0126] 2. Pressure-bearing and sealing conditions of gas pipelines

[0127] 1) During the test, the dry and waterproof raw tape prepared in Example 1 was wrapped with 3 layers. At 32.8 degrees Celsius, the air in the test pipeline was exhausted, and then compressed gas was injected to observe the change of pipeline pressure and record the pressure value when the pressure was constant. The result showed that Example 1 could seal ≥5kg / cm 2 The compressed gas was then exhausted and placed in a 25°C 15% humidity environment for 15 days before being tested again. There was no significant difference between the data from the first test.

[0128] 2) During the test, the waterproof raw tape prepared in Comparative Example 3 was wrapped with 3 layers and then placed in a humidity environment of 25°C and 15% for 2 hours. Then, at 32.8 degrees Celsius, the air in the test pipeline was exhausted, and then compressed gas was injected to observe the changes in pipeline pressure. The pipeline pressure could not reach a constant, and Comparative Example 3 could not seal the compressed gas.

[0129] Effect Example 3: Quality Inspection

[0130] The raw tapes prepared in Example 1 were subjected to quality inspections, and the inspection items included: appearance, size, breakage, pH, water pressure test, high temperature resistance test and low temperature resistance test. The inspection methods and results are shown in Table 3.

[0131] Table 3

[0132]

[0133] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A dry and waterproof raw tape, characterized in that: include: A support layer, and an anti-drying bentonite waterproof layer arranged on one side of the support layer.

2. The anti-drying and waterproofing raw tape according to claim 1, characterized in that: The support layer is a non-woven fabric layer; The anti-drying bentonite waterproof layer is prepared by applying an anti-drying protection liquid on the bentonite waterproof layer; the anti-drying protection liquid penetrates into the bentonite waterproof coating layer and forms an anti-drying protection film layer on the surface of the bentonite waterproof layer; The bentonite waterproof layer is prepared by using bentonite waterproof coating.

3. A method for preparing a dry and waterproof raw tape, characterized in that: The steps include: Step 1, hanging material: evenly hang the bentonite waterproof coating on one side or both sides of the support layer, and then heat and dry it to form a bentonite waterproof layer to obtain a semi-finished raw tape; Step 2, applying anti-drying protection liquid: applying anti-drying protection liquid on the surface of bentonite waterproof layer, the bentonite waterproof layer absorbs the anti-drying protection liquid and forms an anti-drying protection film layer on the surface of the bentonite waterproof layer, thereby forming an anti-drying bentonite waterproof layer and preparing an anti-drying waterproof raw tape.

4. The method for preparing a dry and waterproof raw tape according to claim 3, characterized in that: In step 2, before applying the anti-drying protection liquid, the semi-finished raw tape needs to be cut into strips; after the anti-drying protection film layer is formed, the anti-drying and waterproof raw tape needs to be wound into a roll, packaged and sealed.

5. The method for preparing a dry and waterproof raw tape according to claim 3, characterized in that: Applying the anti-drying protection liquid: applying the anti-drying protection liquid by spraying, coating or dipping; The temperature of the anti-drying protection liquid is ≥40℃.

6. The method for preparing a dry and waterproof raw tape according to claim 3, characterized in that: The bentonite waterproof coating comprises the following raw materials in percentage by weight: Bentonite 40-60%; crack inhibitor 1-3%; toughening agent 3-8%, other additives 0-5%, water 29-54%.

7. The method for preparing a dry and waterproof raw tape according to claim 6, characterized in that: The crack inhibitor is nanocellulose; The toughening agent is water-based polyurethane emulsion; Other additives include one or more of anti-aging agents, ultraviolet absorbers, antioxidants, inorganic nanomaterials, and film-forming agents.

8. The method for preparing a dry and waterproof raw tape according to claim 7, characterized in that: The preparation method of the bentonite waterproof coating comprises: Firstly, a film former and a toughening agent are added into water, and other additives are selectively added, and ultrasonic dispersion is performed to obtain an additive solution; Then, the bentonite is sent to the mixer through a closed conveyor belt, the auxiliary solution is added, and the mixture is stirred for 3-5 minutes to obtain the bentonite waterproof coating.

9. The method for preparing a dry and waterproof raw tape according to claim 3, characterized in that: The anti-drying protective film layer is prepared from an anti-drying protective liquid, and the anti-drying protective liquid includes the following raw materials in percentage by weight: Surfactant 40-60%; Mineral oil 10-20%; Water 30-50%. The surfactant has hydrophilic and lipophilic groups.

10. The method for preparing a dry and waterproof raw tape according to claim 9, characterized in that: The surfactant is alkylphenol polyoxyethylene ether; The mineral oil is white oil; The preparation method of the anti-drying protection liquid comprises: firstly mixing water and alkylphenol polyoxyethylene ether, heating to 50-70°C, stirring to make a uniform liquid, adding white oil, and then homogenizing to obtain the anti-drying protection liquid.

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