Self-crosslinking water-based water-blocking glue, preparation method thereof and application of self-crosslinking water-based water-blocking glue in optical cable water-blocking material

Abstract

The invention discloses a self-crosslinking water-based water-blocking adhesive, a preparation method thereof and an application of the self-crosslinking water-based water-blocking adhesive in an optical cable water-blocking material. The water-blocking adhesive consists of superfine super absorbent resin powder, an acrylic polymerizable mixed solution and a polyvinyl alcohol aqueous solution, wherein the particle size D90 of the super absorbent resin powder is less than 50 microns. The preparation method comprises the following steps: wetting the super absorbent resin powder with alcohol, dispersing in a mixed solution containing high-concentration acrylate, grinding with a colloid mill, and compounding with a polyvinyl alcohol solution to form a stable glue solution. A non-woven fabric or a fiber yarn base material is coated with the glue solution, thermal polymerization crosslinking of monomers can be achieved after drying, and a compact glue layer with cohesiveness and water absorption is formed. The invention effectively solves the problems of serious powder falling and slow water absorption rate of the traditional water-blocking material, has the advantages of fast water-blocking response, firm bonding, environmental friendliness and the like, and is suitable for preparation of water-blocking tapes and water-blocking yarns of optical cables.

Description

Technical Field

[0001] This invention relates to the field of optical cable materials technology, specifically to a self-crosslinking water-blocking adhesive, its preparation method, and its application in optical cable water-blocking materials. Background Technology

[0002] In the manufacturing of optical cables, to prevent moisture from penetrating longitudinally, water-blocking materials such as water-blocking tape or water-blocking yarn are usually filled or wrapped in the gaps between the cable cores. In the existing technology, the main manufacturing method of water-blocking tape for optical cables is as follows: a layer of adhesive is coated on the surface of a substrate such as non-woven fabric, and then granular superabsorbent polymer (SAP) powder (particle size usually between 120 and 200 micrometers) is evenly sprinkled on the coated surface using a powder spreading device. The SAP powder is then adhered to the substrate by the adhesive, and the tape is dried to obtain the final product.

[0003] The aforementioned traditional methods have the following significant drawbacks: First, SAP powder only adheres through surface dots and cannot be completely coated by the adhesive. This inevitably leads to powder shedding during the subsequent production, transportation, and use of the optical cable, affecting not only water-blocking performance but also potentially polluting the production environment and impacting the performance of other internal components. Second, to ensure uniform powder application and control production dust, the SAP powder particle size cannot be too small. This results in a limited specific surface area, causing a slower initial water absorption rate of the water-blocking tape (e.g., a smaller expansion height within 1 minute), affecting the timeliness of the water-blocking response. While using finer SAP powder (e.g., particle size less than 50 micrometers) can improve the water absorption rate, it severely deteriorates the uniformity of powder application and generates a large amount of dust, polluting the environment and endangering the health of operators.

[0004] Therefore, there is an urgent need to develop a new technology for preparing water-blocking materials to solve the problems of severe powder shedding, limited water absorption rate, and unfriendly production environment in existing technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a self-crosslinking water-blocking adhesive. This water-blocking adhesive can stably and uniformly disperse ultrafine superabsorbent resin powder in the system and can be directly coated onto a substrate, thereby preparing water-blocking tapes and yarns for optical cables with low powder shedding rate, fast water absorption rate, and excellent water-blocking performance.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned self-crosslinking water-resistant adhesive.

[0007] Another object of the present invention is to provide the application of the above-mentioned self-crosslinking water-blocking adhesive in the preparation of water-blocking tape or water-blocking yarn for optical cables.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A self-crosslinking water-resistant adhesive, characterized in that it is prepared from raw materials comprising the following components:

[0010] Superabsorbent resin powder with a particle size D90 of less than 50 micrometers;

[0011] A polymerizable mixed solution comprising acrylic monomer, neutralizing agent, crosslinking monomer, initiator and water; wherein the neutralizing agent is used to neutralize acrylic acid partially or completely into acrylate, such that the concentration of acrylate in the mixed solution is not less than 30% (based on the total mass of the solution).

[0012] Aqueous solutions of polyvinyl alcohol;

[0013] And optionally, a suspension stabilizer.

[0014] In the polymerizable mixed solution, the acrylic monomer is acrylic acid; the neutralizing agent is sodium hydroxide or potassium hydroxide, preferably sodium hydroxide; the crosslinking monomer is one or more of N,N'-methylenebisacrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate; and the initiator is a water-soluble initiator such as potassium persulfate or ammonium persulfate.

[0015] The mass ratio of the superabsorbent resin powder to the acrylic monomer in the polymerizable mixed solution is (0.1~1):1, preferably (0.3~0.6):1.

[0016] The concentration of the polyvinyl alcohol aqueous solution is 5%~15%, preferably 8%~12%, and its mass ratio with the polymerizable mixed solution is (0.2~0.8):1.

[0017] The suspension stabilizer can be selected from xanthan gum, sodium carboxymethyl cellulose, or sodium alginate, and the amount added is 0.1% to 1.0% of the total mass of the water-blocking adhesive.

[0018] This invention also provides a method for preparing the above-mentioned self-crosslinking water-resistant adhesive, comprising the following steps:

[0019] S1. Preparation of premixed solution: Acrylic acid, water, neutralizing agent, crosslinking monomer and initiator are mixed in proportion and stirred evenly to obtain a polymerizable mixed solution containing sodium acrylate.

[0020] S2, SAP powder pretreatment: Mix superabsorbent resin powder with a particle size of less than 50 micrometers with anhydrous ethanol or methanol to wet the powder surface with alcohol.

[0021] S3. Primary Dispersion: The SAP powder pretreated in step S2 is added to the polymerizable mixed solution obtained in step S1 and mixed evenly under low-speed stirring to obtain a uniformly dispersed SAP suspension. Due to the high concentration of sodium ions in the mixed solution, the excessive water absorption and swelling of the SAP powder is inhibited, and its water absorption is controlled to about 5 times its own weight, thus maintaining a dispersible state.

[0022] S4. Fine grinding: The suspension obtained in step S3 is ground by a colloid mill to further break down and refine the SAP particles and any small gel clusters that may be formed, ensuring that the particle size in the final colloid is less than 50 micrometers.

[0023] S5. Stabilization and mixing: Add a suspension stabilizer to the adhesive solution after grinding in step S4, stir evenly, and form a stable water-blocking adhesive solution component A.

[0024] S6. Final compounding: Mix component A of the water-blocking adhesive with a predetermined amount of polyvinyl alcohol aqueous solution and stir evenly to obtain the self-crosslinking water-blocking adhesive.

[0025] This invention also provides the application of the self-crosslinking water-blocking adhesive in the preparation of water-blocking materials for optical cables. The specific application method is as follows: the water-blocking adhesive is uniformly coated onto the surface of a substrate such as non-woven fabric, polyester fiber cloth, or polyester fiber yarn by scraping, rolling, or spraying, and then dried at a temperature of 80℃~150℃. During the drying process, moisture evaporates, and simultaneously, monomers in the mixed solution undergo a thermal polymerization reaction to form a crosslinked sodium polyacrylate network structure. This network structure itself has water absorption properties and works synergistically with the uniformly dispersed superabsorbent resin powder to jointly provide water-blocking performance. Finally, the water-blocking adhesive layer is firmly bonded to the substrate, resulting in a dense, almost powder-free water-blocking tape or yarn.

[0026] The beneficial effects of this invention are:

[0027] 1. Effectively solves the problem of powder shedding: By pre-dispersing and "encapsulating" ultrafine SAP powder inside the adhesive, the SAP is firmly wrapped in a self-crosslinking polymer network and polyvinyl alcohol film after drying, resulting in strong adhesion and effectively preventing powder shedding during use.

[0028] 2. Significantly improved water absorption rate: Ultrafine SAP powder with a particle size of less than 50 micrometers was used, which has a huge specific surface area, giving the water-blocking tape a very fast initial water absorption response speed (the water absorption rate is greatly improved in 1 minute).

[0029] 3. Creates a synergistic water-blocking effect: After the sodium acrylate in the adhesive polymerizes, it forms a cross-linked network with water absorption properties, which together with the dispersed SAP powder constitutes a "dual water-absorbing system" and improves the overall water absorption capacity.

[0030] 4. Stable and environmentally friendly process: By using a series of methods such as high ion concentration solution to inhibit premature expansion of SAP, alcohol wetting to prevent agglomeration, fine grinding with colloid mill and addition of suspending agent, the long-term uniform and stable dispersion of ultrafine SAP in water-based system is guaranteed. The entire production process is dust-free and environmentally friendly. Attached Figure Description

[0031] none. Detailed Implementation

[0032] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto.

[0033] Example 1

[0034] S1. Preparation of polymerizable mixed solution: Mix 40g acrylic acid, 60g water, 18g sodium hydroxide (neutralization degree of 80%), 0.2g N,N'-methylenebisacrylamide, and 0.2g potassium persulfate, and stir until completely dissolved.

[0035] S2, SAP pretreatment: Weigh 20g of superabsorbent resin powder with a particle size D90 of 30 micrometers, add 2g of anhydrous ethanol, and gently stir to make the powder surface evenly moistened.

[0036] S3. Add the pretreated SAP powder to the solution in step S1 and stir at 200 rpm for 10 minutes to obtain a preliminary dispersion.

[0037] S4. The initial dispersion is circulated and ground three times through a colloid mill to obtain a fine colloid solution.

[0038] S5. Add 0.5g xanthan gum to the ground adhesive solution and stir until completely dissolved to obtain component A.

[0039] S6. Prepare 50g of a 10% polyvinyl alcohol aqueous solution.

[0040] S7. Mix component A with a polyvinyl alcohol aqueous solution and stir evenly to obtain a self-crosslinking water-resistant adhesive.

[0041] Application Example 1

[0042] The water-blocking adhesive prepared above was evenly coated onto a 40g / m² polyester nonwoven fabric using a scraper, with a wet coating weight of approximately 80g / m². It was then dried in an oven at 120℃ for 3 minutes. After cooling, the water-blocking tape for optical cables was obtained.

[0043] Tests showed that the water-blocking tape has a smooth and dense surface with no powder shedding. Its expansion height reaches 15cm in 1 minute (YD / T1115.1-2023 standard method), far exceeding that of traditional powder-spreading water-blocking tapes (usually less than 10cm).

[0044] Example 2

[0045] S1. Preparation of polymerizable mixed solution: Mix 50g acrylic acid, 75g water, 28g sodium hydroxide (neutralization degree is 100%), 5g hydroxyethyl acrylate, 0.2g N,N'-methylenebisacrylamide, and 0.3g ammonium persulfate.

[0046] S2, SAP pretreatment: Weigh 30g of superabsorbent resin powder with a particle size D90 of 40 micrometers and add 3g of methanol to wet it.

[0047] S3. The subsequent steps are the same as in Example 1, but component A is mixed with 40g of a 12% polyvinyl alcohol aqueous solution.

[0048] Application Example 2

[0049] The water-blocking adhesive from Example 2 was coated onto polyester fiber yarn and dried to obtain water-blocking yarn. Its powder shedding rate was reduced by more than 95% compared with traditional products, and its water absorption rate reached 80 mL / g in 1 minute (YD / T 1115.2-2023 standard method).

[0050] Comparative Example

[0051] Using a traditional process: polyvinyl alcohol adhesive is coated onto the same nonwoven fabric, followed by the application of SAP powder with a particle size of 150 microns, and then dried to obtain the water-blocking tape. This product exhibits significant powder shedding, and its expansion height is only 8 cm per minute.

[0052] The above embodiments demonstrate that the self-crosslinking water-blocking adhesive and its preparation method provided by the present invention can effectively solve the problems of the prior art and prepare high-performance water-blocking materials for optical cables.

[0053] It should be understood that the above description is only a preferred embodiment of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A self-crosslinking water-based water-blocking adhesive, characterized in that, It is prepared from raw materials containing the following components: Superabsorbent resin powder with a particle size D90 of less than 50 micrometers; A polymerizable mixed solution comprising acrylic acid, a neutralizing agent, a crosslinking monomer, an initiator, and water, wherein the neutralizing agent is used to partially or completely neutralize the acrylic acid, such that the concentration of acrylate in the mixed solution is not less than 30% of the total mass of the solution; Aqueous solution of polyvinyl alcohol.

2. The self-crosslinking water-based water-blocking adhesive according to claim 1, characterized in that, The mass ratio of the superabsorbent resin powder to the acrylic acid in the polymerizable mixed solution is (0.1~1):

1.

3. The self-crosslinking water-based water-blocking adhesive according to claim 2, characterized in that, The mass ratio of the superabsorbent resin powder to the acrylic acid in the polymerizable mixed solution is (0.3~0.6):

1.

4. The self-crosslinking water-based water-blocking adhesive according to claim 1, characterized in that, The crosslinking monomer is one or more of N,N'-methylenebisacrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate; the initiator is potassium persulfate or ammonium persulfate.

5. The self-crosslinking water-based water-blocking adhesive according to claim 1, characterized in that, The concentration of the polyvinyl alcohol aqueous solution is 5%~15%, and its mass ratio with the polymerizable mixed solution is (0.2~0.8):

1.

6. The self-crosslinking water-based water-blocking adhesive according to claim 5, characterized in that, The concentration of the polyvinyl alcohol aqueous solution is 8% to 12%.

7. The self-crosslinking water-resistant adhesive according to any one of claims 1-6, characterized in that, It also contains a suspension stabilizer, which is xanthan gum, sodium carboxymethyl cellulose, or sodium alginate.

8. A method for preparing a self-crosslinking water-resistant adhesive according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix acrylic acid, water, neutralizing agent, crosslinking monomer and initiator to prepare a polymerizable mixed solution; S2. Pre-treat the surface of the superabsorbent resin powder by wetting it with an alcohol solvent; S3. Add the powder pretreated in step S2 to the solution in step S1 and disperse it evenly to obtain a suspension. S4. Grind the suspension obtained in step S3 to obtain a gel with a particle size of less than 50 micrometers. S5. Add a suspension stabilizer to the adhesive solution obtained in step S4 and disperse it evenly. S6. Mix the adhesive solution obtained in step S5 with a polyvinyl alcohol aqueous solution to obtain the final product.

9. The preparation method according to claim 8, characterized in that, The grinding process in step S4 is carried out using a colloid mill.

10. The preparation method according to claim 8, characterized in that, The alcohol solvent mentioned in step S2 is anhydrous ethanol or methanol.

11. A water-blocking material for optical cables, characterized in that, It consists of a substrate and a water-blocking adhesive layer coated on the surface of the substrate. The water-blocking adhesive layer is formed by coating and drying the self-crosslinking water-blocking adhesive according to any one of claims 1-7. The drying process simultaneously causes the polymerizable mixed solution to undergo a polymerization reaction.

12. The water-blocking material for optical cables according to claim 11, characterized in that, The substrate is non-woven fabric or polyester fiber yarn; the water-blocking material of the optical cable is water-blocking tape or water-blocking yarn.