Stabilizer as well as preparation method, application and application method thereof

Abstract

The invention discloses a stabilizer as well as a preparation method, application and an application method thereof, and belongs to the technical field of chemical materials. The invention provides a stabilizer which is composed of an anionic surfactant, a nonionic surfactant and a plasticizer, the anionic surfactant is any one of lauryl sodium sulfate, sodium dodecyl benzene sulfonate and sodium lauryl sulfoacetate; the nonionic surfactant is any one of polyethylene glycol, alkylphenol polyoxyethylene ether, fatty alcohol-polyoxyethylene ether and MS-1; and the plasticizer is any one of dibutyl phthalate and dioctyl phthalate. According to the stabilizer provided by the invention, through compounding of three specific components and precise mass ratio regulation and control, when a mixed system of the VAE emulsion and the natural latex is stabilized, a production process of the VAE emulsion does not need to be replaced, and through a post-addition mode, the problem that the viscosity is greatly changed when the VAE emulsion and the natural latex are blended can be solved, the operation method is simple, and the application range is wide.

Description

Technical Field

[0001] This invention relates to the field of chemical materials, and in particular to a stabilizer, its preparation method, application, and application method. Background Technology

[0002] Natural latex, as a high-performance natural polymer colloid, is widely used in numerous fields such as medical gloves, condoms, adhesives, and textile coatings due to its excellent elasticity, mechanical strength, and biocompatibility. It is a key basic material in industrial production and people's livelihood. However, natural latex itself has significant performance shortcomings and application limitations: On the one hand, the unsaturated double bonds in its molecular structure are easily affected by environmental factors such as oxygen, ultraviolet radiation, and high temperatures, resulting in poor aging resistance of products and easy hardening and cracking after long-term use. At the same time, natural latex has insufficient heat stability and weak tolerance to organic solvents, limiting its application in high-temperature or solvent contact scenarios. On the other hand, the production of natural latex depends on rubber tree planting, which is significantly affected by factors such as region, climate, and pests and diseases. Not only is the stability of the source difficult to guarantee, but the cost of raw material collection and processing is also high, resulting in the long-term high price of natural latex and its products, increasing the production costs of downstream enterprises.

[0003] To compensate for the shortcomings of natural latex, the industry commonly adopts a technical approach of blending natural latex with synthetic latex. Through molecular design and polymerization process control, synthetic latex can acquire specific properties lacking in natural latex. For example, styrene-butadiene latex exhibits excellent aging resistance, while chloroprene latex demonstrates outstanding solvent resistance, enabling targeted improvement of specific performance deficiencies in blended systems. Simultaneously, synthetic latex raw materials are widely available and have lower production costs. Blending with natural latex not only reduces overall formulation costs but also decreases dependence on natural latex, alleviating its scarcity. Therefore, it has become an important development direction for the latex industry.

[0004] VAE (ethylene-vinyl acetate copolymer) emulsions, as an important category of synthetic latexes, exhibit excellent film-forming properties, low-temperature flexibility, and adhesion to various substrates due to the combination of the flexibility of ethylene units and the adhesiveness of vinyl acetate units in their molecular chains. They have already achieved large-scale applications in fields such as architectural coatings, paper binding, and textile finishing. However, in the process of blending VAE emulsions with natural latex to prepare high-performance composite latexes, the industry generally faces a key technical challenge: the viscosity of the blended system increases significantly in a short period, leading to a sharp decrease in the fluidity of the blended emulsion. This makes it impossible to process using conventional coating, impregnation, or extrusion equipment, resulting in reduced production efficiency, uneven coating thickness, or even equipment and pipeline blockage, directly causing production interruptions. Therefore, developing a stabilizer that can effectively solve the problem of significant viscosity increase in VAE emulsion-natural latex blends has become a key requirement for promoting the industrial application of this type of composite latex. Summary of the Invention

[0005] This invention provides a stabilizer, its preparation method, application, and application method, which can solve the problem of significant viscosity increase when VAE emulsion is blended with natural latex in the prior art.

[0006] The objective of this invention can be achieved through the following technical solutions: The first objective of this invention is to provide a stabilizer composed of anionic surfactants, nonionic surfactants, and plasticizers. The anionic surfactant is any one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and sodium lauryl sulfoacetate. The nonionic surfactant is any one of polyethylene glycol, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and MS-1. The plasticizer is either dibutyl phthalate or dioctyl phthalate; The mass ratio of the anionic surfactant, nonionic surfactant, and plasticizer is (7-9):(1-3):(0.2-0.5). As a preferred embodiment of the present invention, the polyethylene glycol is either PEG-400 or PEG-600.

[0007] As a preferred embodiment of the present invention, the alkylphenol polyoxyethylene ether is any one of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and OP-10.

[0008] As a preferred embodiment of the present invention, the fatty alcohol polyoxyethylene ether is any one of AEO-9, EH-3, and EH-9.

[0009] A second objective of this invention is to provide a method for preparing a stabilizer, comprising the following steps: Weigh out the anionic surfactant, nonionic surfactant, and plasticizer separately, add them to distilled water, heat and stir until completely dissolved, and cool to room temperature for later use.

[0010] As a preferred embodiment of the present invention, the heating and stirring temperature is 60-80℃ and the time is 20-40min.

[0011] A third objective of this invention is to provide an application of a stabilizer for stabilizing a mixture of VAE emulsion and natural latex.

[0012] The fourth objective of this invention is to provide a method for applying a stabilizer, comprising the following steps: S1. Add the stabilizer to the VAE emulsion and stir until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add the mixture from S1 to the natural latex and start stirring until the VAE emulsion and natural latex are evenly mixed. Then add the defoamer and vacuum for 2-5 hours to eliminate the foam in the blended emulsion.

[0013] As a preferred embodiment of the present invention, in step S1, the viscosity of the VAE emulsion is 1910-5049 mPa·s.

[0014] As a preferred embodiment of the present invention, in step S1, the stirring speed is 50-500 r / min and the stirring time is 30-100 min.

[0015] As a preferred embodiment of the present invention, the amount of stabilizer added accounts for 0.1%-1% of the mass of the VAE emulsion.

[0016] As a preferred embodiment of the present invention, the mass ratio of the mixture to natural latex is (5-9):(1-5).

[0017] The beneficial effects of this invention are: 1. This invention provides a stabilizer that, through the precise mass ratio control of a compound of three specific components, achieves the core advantages of synergistic stability, strong compatibility, and ease of use when stabilizing a VAE emulsion and natural latex mixture system, as detailed below: Anionic surfactants such as sodium dodecyl sulfate and sodium dodecylbenzene sulfonate adsorb onto the surface of latex particles through hydrophobic interactions. The hydrophilic groups (and their negatively charged ionic heads) face the aqueous phase, forming a negatively charged layer on the particle surface. This charged layer prevents latex particles from approaching each other and agglomerating through electrostatic repulsion, fundamentally inhibiting stratification or precipitation. It also constitutes the largest proportion (7-9 parts), providing core support for the stabilizing effect.

[0018] Nonionic surfactants such as polyethylene glycol and alkylphenol polyoxyethylene ethers, although lacking obvious charge, can form hydrogen bonds with water through their polyoxyethylene chains, creating a steric hindrance layer on the surface of latex particles. This layer, in conjunction with the charge layer of anionic surfactants, further expands the repulsion distance between particles, significantly improving stability. Simultaneously, nonionic surfactants can reduce the interfacial tension between VAE emulsions and natural latex, resolving the poor compatibility and flocculation issues caused by differences in polarity and structure between the two types of latex. This prevents particle agglomeration at the interface, and a dosage of 1-3 parts can precisely control the interface optimization effect, avoiding both insufficient dosage leading to interfacial accumulation and excessive dosage causing system thickening, ensuring stable viscosity during mixing.

[0019] Plasticizers such as dibutyl phthalate and dioctyl phthalate can penetrate into the interior of natural latex particles, disrupting these pre-crosslinking points and preventing the formation of their internal structure. This prevents the viscosity increase of the mixture due to the self-polymerization of natural latex, maintaining its good flowability and processability. A trace amount of 0.2-0.5 parts is sufficient to achieve this effect without interfering with the system.

[0020] The mass ratio of (7-9):(1-3):(0.2-0.5) ensures that electrostatic stability (anionic surfactants make up the majority), steric hindrance (nonionic surfactants in appropriate amounts) is used as an auxiliary and safety factor, and plasticizers (small amount but key) are used to break the characteristics of pre-crosslinking points and achieve breakthroughs. The optimal combination of these three factors produces a synergistic effect.

[0021] 2. The stabilizer and corresponding usage method of this invention do not require adjustment or replacement of existing VAE emulsion production processes. Simply adding it post-processingly effectively solves the problem of significant viscosity changes when blending VAE emulsions with natural latex. The operation is simple and easy to learn, adaptable to different blending ratios and application scenarios, and has a wide range of applications. During the blending of VAE emulsions and natural latex, the original protective layer substances on the surface of the particles undergo redistribution due to interfacial interactions. This redistribution can easily disrupt system stability and cause abnormal viscosity. This invention, by adding a suitable emulsifier, can precisely adjust the composition and structure of the surface protective layer of the two types of latex particles, fundamentally suppressing significant viscosity increases or decreases and ensuring that the viscosity of the blended system remains within the applicable range for the process. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example

[0024] Example 1

[0025] This embodiment provides a method for applying a stabilizer, including the following steps: S1. Preparation of stabilizer: Add 3g sodium dodecyl sulfate, 2g PEG-400 and 0.2g dibutyl phthalate to 25mL of water, heat and stir at 70℃ for 30min until the mixture is uniform; S2. Add 1g of stabilizer to 450g of VAE emulsion (viscosity: 4450mpa·s) and stir at 100r / min for 30min until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add 450g of the mixture in S2 to 50g of natural latex, turn on the stirrer until the VAE emulsion and natural latex are evenly mixed, then add the defoamer, and then vacuum for 2 hours to eliminate the foam in the blended emulsion, thus obtaining a blended emulsion of VAE emulsion and natural latex.

[0026] Example 2

[0027] This embodiment provides a method for applying a stabilizer, including the following steps: S1. Preparation of stabilizer: Add 3g sodium dodecyl sulfate, 2g PEG-400 and 0.2g dibutyl phthalate to 25mL of water, heat and stir at 70℃ for 30min until the mixture is uniform; S2. Add 1g of stabilizer to 450g of VAE emulsion (viscosity: 3010mpa·s) and stir at 100r / min for 30min until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add 450g of the mixture in S2 to 50g of natural latex, turn on the stirrer until the VAE emulsion and natural latex are evenly mixed, then add the defoamer, and then vacuum for 2 hours to eliminate the foam in the blended emulsion, thus obtaining a blended emulsion of VAE emulsion and natural latex.

[0028] Example 3

[0029] This embodiment provides a method for applying a stabilizer, including the following steps: S1. Preparation of stabilizer: Add 5g sodium lauryl sulfoacetate, 1g TX-100, and 0.2g dibutyl phthalate to 25mL of water, heat and stir at 70℃ for 30min until the mixture is uniform. S2. Add 1g of stabilizer to 450g of VAE emulsion (viscosity: 1910mpa·s) and stir at 100r / min for 30min until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add 450g of the mixture in S2 to 50g of natural latex, turn on the stirrer until the VAE emulsion and natural latex are evenly mixed, then add the defoamer, and then vacuum for 2 hours to eliminate the foam in the blended emulsion, thus obtaining a blended emulsion of VAE emulsion and natural latex.

[0030] Example 4

[0031] This embodiment provides a method for applying a stabilizer, including the following steps: S1. Preparation of stabilizer: Add 5g sodium lauryl sulfoacetate, 1g TX-100 and 0.5g dibutyl phthalate to 25mL of water, heat and stir at 70℃ for 30min until the mixture is uniform. S2. Add 1g of stabilizer to 450g of VAE emulsion (viscosity: 5049mpa·s) and stir at 100r / min for 30min until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add 450g of the mixture in S2 to 50g of natural latex, turn on the stirrer until the VAE emulsion and natural latex are evenly mixed, then add the defoamer, and then vacuum for 2 hours to eliminate the foam in the blended emulsion, thus obtaining a blended emulsion of VAE emulsion and natural latex.

[0032] Comparative Example

[0033] Comparative Examples 1-7

[0034] Compared with Example 1, the difference is that the mass of sodium dodecyl sulfate, PEG-400 and dibutyl phthalate in Comparative Examples 1-7 is as shown in Table 1, while the other raw materials and steps are the same as in Example 1.

[0035] Table 1

[0036] Test case

[0037] The viscosities of the VAE emulsions blended with natural latex in Examples 1-4 and Comparative Examples 1-7 were tested using a Brookfield instrument. The test temperature was 25°C; rotor: #4; rotation speed: 60 r / min. The formula for calculating the viscosity change is as follows: The test results are shown in Table 2. Table 2

[0038] As shown in Table 1, Examples 1-4, which used the stabilizer of this invention, exhibited viscosity changes within 5% after blending with natural latex. Comparative Examples 1-7, which adjusted the amount of stabilizer, revealed a significant increase in viscosity of the VAE emulsion after blending with natural latex. This indicates that anionic surfactants such as sodium dodecyl sulfate and sodium dodecylbenzene sulfonate adsorb onto the surface of latex particles through hydrophobic interactions. The hydrophilic groups (and their negatively charged ionic heads) face the aqueous phase, forming a negatively charged layer on the particle surface. This charged layer prevents latex particles from approaching and aggregating through electrostatic repulsion, fundamentally inhibiting stratification or precipitation. Furthermore, this layer constitutes the largest proportion (7-9 parts), providing core support for the stabilizing effect.

[0039] Nonionic surfactants such as polyethylene glycol and alkylphenol polyoxyethylene ethers, although lacking obvious charge, can form hydrogen bonds with water through their polyoxyethylene chains, creating a steric hindrance layer on the surface of latex particles. This layer, in conjunction with the charge layer of anionic surfactants, further expands the repulsion distance between particles, significantly improving stability. Simultaneously, nonionic surfactants can reduce the interfacial tension between VAE emulsions and natural latex, resolving the poor compatibility and flocculation issues caused by differences in polarity and structure between the two types of latex. This prevents particle agglomeration at the interface, and a dosage of 1-3 parts can precisely control the interface optimization effect, avoiding both insufficient dosage leading to interfacial accumulation and excessive dosage causing system thickening, ensuring stable viscosity during mixing.

[0040] Plasticizers such as dibutyl phthalate and dioctyl phthalate can penetrate and act on the interfacial protective layer of natural latex particles, increasing their flexibility and deformability. The flexible particles have weak aggregation, thus preventing particle agglomeration and contributing to maintaining the stability of the overall viscosity of the mixture. A trace amount of 0.2-0.5 parts is sufficient to achieve this effect without interfering with the system.

[0041] The stabilizer and its application method of the present invention do not require changes to the production process of VAE emulsion. By adding it later, the problem of large viscosity changes that occur when VAE emulsion is blended with natural latex can be solved. The operation method is simple and has a wide range of applications.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stabilizer, characterized in that, It is composed of anionic surfactants, nonionic surfactants, and plasticizers; The anionic surfactant is any one of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and sodium lauryl sulfoacetate. The nonionic surfactant is any one of polyethylene glycol, alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and MS-1; The plasticizer is either dibutyl phthalate or dioctyl phthalate; The mass ratio of the anionic surfactant, nonionic surfactant and plasticizer is (7-9):(1-3):(0.2-0.5).

2. The stabilizer according to claim 1, characterized in that, The polyethylene glycol is either PEG-400 or PEG-600.

3. The stabilizer according to claim 1, characterized in that, The alkylphenol polyoxyethylene ether is any one of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and OP-10.

4. The stabilizer according to claim 1, characterized in that, The fatty alcohol polyoxyethylene ether is any one of AEO-9, EH-3 and EH-9.

5. A method for preparing a stabilizer, used to prepare the stabilizer according to any one of claims 1-4, characterized in that, Includes the following steps: Weigh out the anionic surfactant, nonionic surfactant, and plasticizer separately, add them to distilled water, heat and stir until completely dissolved, and cool to room temperature for later use.

6. The method for preparing the stabilizer according to claim 5, characterized in that, The heating and stirring temperature is 60-80℃, and the time is 20-40 minutes.

7. The application of the stabilizer according to claim 1, characterized in that, Stabilizers are used to stabilize the mixture of VAE emulsion and natural latex.

8. The method of applying the stabilizer according to claim 7, characterized in that, Includes the following steps: S1. Add the stabilizer to the VAE emulsion and stir until the stabilizer and VAE emulsion are fully mixed to obtain a mixture. S2. Add the mixture from S1 to the natural latex and start stirring until the VAE emulsion and natural latex are evenly mixed. Then add the defoamer and vacuum for 2-5 hours to eliminate the foam in the blended emulsion.

9. The application method according to claim 8, characterized in that, In step S1, the viscosity of the VAE emulsion is 1910-5049 mPa·s; The stirring speed is 50-500 r / min, and the stirring time is 30-100 min.

10. The application method according to claim 8, characterized in that, The amount of stabilizer added is 0.1%-1% of the mass of the VAE emulsion.

11. The application method according to claim 8, characterized in that, The mass ratio of the mixture to natural latex is (5-9):(1-5).

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