A cationic polyacrylate waterproofing agent dispersion and its preparation method

Abstract

The present invention discloses a cationic polyacrylate waterproofing agent dispersion and a preparation method thereof, belonging to the field of waterproofing agent dispersions. The preparation method comprises the following steps: S1: Glycidyl methacrylate and acrylate monomers are mixed and reacted in a solvent to form a first polymer, and the first polymer is a polymer containing epoxy groups; S2: The first polymer is mixed with a double long-chain alkylamine, so that the epoxy groups of the first polymer and the secondary amino groups in the double long-chain alkylamine undergo a ring-opening reaction to form a second polymer, and the molecular structure of the second polymer contains hydroxyl groups and amino groups; S3: The second polymer is mixed and reacted with a monocarboxyl silicone oil to form a third polymer; S4: The third polymer is reacted with an organic acid to form a mixture containing a fourth polymer; S5: The mixture is post-treated.

Description

Technical Field

[0001] The invention relates to the field of fine chemicals, in particular to a cationic polyacrylate waterproofing agent dispersion and a preparation method thereof. Background Art

[0002] The waterproof properties of textiles through waterproof finishing can greatly expand the application range of textiles. In the current printing and dyeing process, cationic fluorinated polyacrylate emulsions are widely used as waterproof agents for textiles. The perfluoroalkyl side chains with extremely low surface energy are enriched on the surface of the fabric, making the finished fabric show extremely low surface energy, thus achieving waterproof and even oil-proof properties.

[0003] With increasingly stringent environmental regulations, the use of fluorine-containing waterproofing agents will be restricted due to their potential harm to the environment and human health, and fluorine-free waterproofing agents will gradually become the mainstream choice in the market. Fluorine-free waterproofing agents do not contain fluorine and will not pollute the environment during use. Currently, the fluorine-free waterproofing agents on the market are mainly cationic polyacrylate emulsions. During the preparation process of such products, silicone with low surface energy and long-chain alkyl (meth) acrylates are generally added to copolymerize with acrylate monomers. The synergistic effect of silicone and long-chain alkyl enables such products to achieve good waterproof performance; silicone with low surface energy is the main raw material for preparing fluorine-free waterproofing agents, but in traditional emulsion polymerization, long-chain organosiloxanes (silicone oils) are difficult to copolymerize to the molecular chain, and are often used in products in the form of compounding, so a large amount of emulsifiers are needed to emulsify the silicone oil to ensure stability. However, even so, there are problems with the stability of such products during storage, and the silicone oil is very easy to precipitate and float on the surface. In addition, the preparation process of such products is the same as the traditional emulsion polymerization process. Generally, cationic emulsifiers are added to provide stability, and hydrophilic initiators are used as initiators for the polymerization reaction. Therefore, the large-scale use of small molecule emulsifiers in such products can easily lead to a large amount of foam generated during the use of such products, which brings great inconvenience to production. At the same time, it is easy to form foam spots on the cloth surface, affecting the quality of the finished cloth; at the same time, the emulsifier is easy to migrate to the air interface during the film formation process, thereby enriching on the film-forming surface, which enhances the hydrophilicity of the film-forming surface. In addition, the use of hydrophilic initiators also makes the molecular chain contain more hydrophilic groups. The combined effect of the two will greatly affect the actual application effect of the waterproofing agent. In view of the above problems, the market urgently needs to improve the existing fluorine-free cationic polyacrylate waterproofing agent system to overcome the existing defects. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the prior art and disclose a method for preparing a cationic polyacrylate waterproofing agent dispersion, the steps of which are as follows:

[0005] S1: Mix glycidyl methacrylate and acrylate monomers in a solvent for reaction to form a first polymer, which is a polymer containing epoxy groups;

[0006] S2: Mix the first polymer with a double long-chain alkylamine to cause the epoxy groups in the first polymer to undergo a ring-opening reaction with the secondary amino groups in the double long-chain alkylamine, forming a second polymer. The molecular structure of the second polymer contains hydroxyl and amino groups;

[0007] S3: React the second polymer with a monocarboxyl silicone oil to form a third polymer

[0008] S4: React the third polymer with an organic acid to form a mixture containing a fourth polymer;

[0009] S5: Post-treat the mixture.

[0010] In an improved scheme, the acrylate monomer is butyl acrylate, and the solvent is diethylene glycol butyl ether.

[0011] In an improved scheme, step S1 is: Add diethylene glycol butyl ether to a container, and dropwise add a monomer mixture and an initiator solution. The monomer mixture is a mixture of glycidyl methacrylate, styrene, and butyl acrylate, and the initiator solution is obtained by dissolving benzoyl peroxide in diethylene glycol butyl ether.

[0012] In an improved scheme, the double long-chain alkylamine is ditetradecylamine.

[0013] In an improved scheme, the monocarboxyl silicone oil is BY16-880.

[0014] In an improved scheme, the organic acid is one or a mixture of formic acid, acetic acid, and propionic acid.

[0015] In an improved scheme, step S3 is: Add BY16-880 to a container containing the second polymer and stir for reaction.

[0016] In an improved scheme, step S2 is: Cool the mixture containing the first polymer to 80 °C, slowly add ditetradecylamine, and then carry out a heat preservation reaction.

[0017] In an improved scheme, the step of post-treating the mixture is: Add ionic water and carry out high-speed emulsification and dispersion.

[0018] This application also discloses a cationic polyacrylate waterproofing agent dispersion prepared by the described method.

[0019] This application copolymerizes glycidyl methacrylate with other acrylate monomers to introduce epoxy groups onto the polymer molecular chain. Then, through the ring-opening reaction of the epoxy groups with the secondary amino groups in the bis-long-chain alkylamine, while generating a tertiary amine structure, hydrophobic long-chain alkyl groups are also introduced into the molecular structure of the polymer (as shown in Figure 1 ). In addition, the generated hydroxyl groups can serve as reactive groups for subsequent curing and crosslinking, and can be fixed on the fabric under the action of an externally added crosslinking agent, thus meeting the fastness requirements for washing of the waterproofing agent. Then, mono-carboxyl silicone oil is added, and the long-chain siloxane is fixed on the polymer molecular chain through an ionic bond by the salt-forming reaction of the carboxyl silicone oil with the amino group. Finally, small molecule organic acids are added to neutralize the remaining amino groups, generating a quaternary ammonium salt structure on the molecular chain, endowing it with cationicity while ensuring the product is soluble in water.

[0020] In traditional silicone-modified polyacrylate waterproofing agents, the silicone oil is basically dispersed in the system by emulsification and compounding. In this invention, the salt-forming reaction of the mono-carboxyl silicone oil with the amino groups on the polymer molecular chain fixes the long-chain polysiloxane on the polyacrylate molecular chain through an ionic bond, so the stability is stronger. Different from the conventional cationic waterproofing agent emulsion that requires adding a large amount of cationic and non-ionic emulsifiers during the preparation process, the cationic acrylate waterproofing agent dispersion prepared in this invention does not use small molecule emulsifiers during the preparation process. It neutralizes the tertiary amino groups on the polymer molecular chain with an acid to form an ionizable quaternary ammonium salt, which not only endows cationicity but also ensures its stable dispersion in water. Therefore, the cationic waterproofing agent dispersion prepared in this invention basically eliminates the foam problem caused by the introduction of a large amount of emulsifiers during the use of the conventional waterproofing agent emulsion, and also avoids to a certain extent the negative impact on the waterproof effect caused by the enrichment of small molecule emulsifiers on the film surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the ring-opening reaction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The present invention will be specifically described below through examples. It is necessary to point out here that these examples are only used to further illustrate the present invention and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention above should fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0023] Example 1:

[0024] Add 20 g of diethylene glycol butyl ether into a four-necked flask equipped with a thermometer, a stirrer, a condenser and a monomer dropping device. Start the stirring and heating devices, and introduce nitrogen for protection. Heat up to 120 °C, and dropwise add the monomer mixture and the initiator solution respectively. The monomer mixture is a mixture of 7 g of glycidyl methacrylate, 18 g of styrene and 25 g of butyl acrylate, and the initiator solution is obtained by dissolving 0.2 g of benzoyl peroxide in 1 g of diethylene glycol butyl ether. Control the dropping time within 4 h. After the dropping is completed, dissolve 0.1 g of benzoyl peroxide in 0.5 g of diethylene glycol butyl ether and use it as a post-elimination initiator, add it to the system and then keep the temperature for reaction for 1 h. After the heat preservation is completed, lower the reaction temperature to 80 °C, slowly add 20 g of ditetradecylamine within 1 h, and then keep the temperature for reaction for 2 h. Under the condition of maintaining the temperature, first add 8 g of BY16-880 and stir for 30 min, then add 2.0 g of formic acid and stir well for 30 min; then lower the material temperature to 70 °C, add 200 g of ionized water, and carry out high-speed emulsification and dispersion for 30 min. After the dispersion is completed, filter to obtain a cationic polyacrylate waterproofing agent dispersion.

[0025] Example 2:

[0026] Add 20 g of dipropylene glycol butyl ether into a four-necked flask equipped with a thermometer, a stirrer, a condenser and a monomer dropping device. Start the stirring and heating devices, and introduce nitrogen for protection. Heat up to 130 °C, and dropwise add the monomer mixture and the initiator solution respectively. The monomer mixture is a mixture of 10 g of glycidyl methacrylate, 20 g of styrene and 20 g of butyl acrylate, and the initiator solution is obtained by dissolving 0.2 g of benzoyl peroxide in 1 g of dipropylene glycol butyl ether. Control the dropping time within 4 h. After the dropping is completed, dissolve 0.1 g of benzoyl peroxide in 0.5 g of dipropylene glycol butyl ether and use it as a post-elimination initiator, add it to the system and then keep the temperature for reaction for 1 h. After the heat preservation is completed, lower the reaction temperature to 80 °C, slowly add 30 g of dihexadecylamine within 1 h, and then keep the temperature for reaction for 2 h. Under the condition of maintaining the temperature, first add 9 g of BY16-880 and stir for 30 min, then add 3.3 g of acetic acid and stir well for 30 min; then lower the material temperature to 70 °C, add 250 g of ionized water, and carry out high-speed emulsification and dispersion for 30 min. After the dispersion is completed, filter to obtain a cationic polyacrylate waterproofing agent dispersion.

[0027] Example 3:

[0028] Add 20 g of propylene glycol methyl ether into a four-necked flask equipped with a thermometer, a stirrer, a condenser and a monomer dropping device. Start the stirring and heating devices and introduce nitrogen for protection. Heat up to 130 °C and dropwise add a monomer mixture solution and an initiator solution respectively. The monomer mixture solution is a mixture of 8 g of glycidyl methacrylate, 20 g of styrene and 21 g of butyl acrylate, and the initiator solution is obtained by dissolving 0.2 g of benzoyl peroxide in 1 g of propylene glycol methyl ether. Control the dropping time within 4 h. After the dropping is completed, dissolve 0.1 g of benzoyl peroxide in 0.5 g of propylene glycol methyl ether and use it as a post-elimination initiator, add it to the system and then keep the temperature for reaction for 1 h. After the heat preservation is completed, lower the reaction temperature to 80 °C, slowly add 25 g of dioctadecylamine within 1 h, and then keep the temperature for reaction for 2 h. Under the condition of maintaining the temperature, first add 8 g of BY16-880 and stir for 30 min, then add 2.5 g of acetic acid and stir well for 30 min; then lower the material temperature to 70 °C, add 240 g of ionized water, and carry out high-speed emulsification and dispersion for 30 min. After the dispersion is completed, filter to obtain a cationic polyacrylate waterproofing agent dispersion.

[0029] Example 4:

[0030] Add 20 g of ethylene glycol butyl ether into a four-necked flask equipped with a thermometer, a stirrer, a condenser and a monomer dropping device. Start the stirring and heating devices and introduce nitrogen for protection. Heat up to 130 °C and dropwise add a monomer mixture solution and an initiator solution respectively. The monomer mixture solution is a mixture of 9 g of glycidyl methacrylate, 21 g of styrene and 20 g of butyl acrylate, and the initiator solution is obtained by dissolving 0.2 g of benzoyl peroxide in 1 g of ethylene glycol butyl ether. Control the dropping time within 4 h. After the dropping is completed, dissolve 0.1 g of benzoyl peroxide in 0.5 g of ethylene glycol butyl ether and use it as a post-elimination initiator, add it to the system and then keep the temperature for reaction for 1 h. After the heat preservation is completed, lower the reaction temperature to 80 °C, slowly add a mixture of 15 g of dioctadecylamine and 15 g of dicetylamine within 1 h, and then keep the temperature for reaction for 2 h. Under the condition of maintaining the temperature, first add 9 g of BY16-880 and stir for 30 min, then add 3 g of acetic acid and stir well for 30 min; then lower the material temperature to 70 °C, add 270 g of ionized water, and carry out high-speed emulsification and dispersion for 30 min. After the dispersion is completed, filter to obtain a cationic polyacrylate waterproofing agent dispersion.

[0031] Performance test:

[0032] (1) Determination of the ξ potential of the dispersion: First, dilute the above Examples 1-4 with deionized water to an effective solid content of 1%, and then measure them with a Zetasizer Nano S90 laser particle size-potential analyzer. The results are shown in Table 1:

[0033] Table 1 Results of ξ potential determination of examples

[0034] sample Example 1 Example 2 Example 3 Example 4 ζ potential 25.35 mV 29.45 mV 26.42 mV 27.78 mV

[0035] The results show that the ζ potential of Examples 1-4 are all positive, indicating that they are all cationic dispersions.

[0036] (2) Determination of waterproof performance: First, dilute the above Examples 1-4 with deionized water to an effective solid content of 1%, and use the padding process with 80, specifically: one dip and one nip (pressure 2 kg / cm 2 ) → drying (100 °C) → curing in a stenter (cotton: 160 °C × 1.5 min; polyester-cotton: 180 °C × 1.5 min) → measure the waterproof effect after moisture regain. Conduct the waterproof grade test according to the standard of GB / T 4745-1997:

[0037] Grade 0: Both the front and back sides of the fabric are wetted.

[0038] Grade 1: Almost all of the front side is wetted.

[0039] Grade 2: More than half of the front surface is wetted.

[0040] Grade 3: Only a small amount of discontinuous parts on the front side are wetted. Grade 4: The front side is not wetted but there are a small number of liquid droplets adhering. Grade 5: The front side is neither wetted nor have liquid droplets adhering. Test results of the waterproof performance of the examples:

[0041] 65 / 35 polyester-cotton shuttle fabric pure cotton yarn drill Example 1 Grade 3-4 Grade 3-4 Example 2 Grade 4 Grade 4 Example 3 Grade 4-5 Grade 4-5 Example 4 Grade 4 Grade 4 。

Claims

1. A preparation method of a cationic polyacrylate waterproofing agent dispersion, characterized in that, The steps are as follows: S1: Add diethylene glycol butyl ether into a container, and dropwise add a monomer mixture and an initiator solution. The monomer mixture is a mixture of glycidyl methacrylate, styrene and butyl acrylate to form a first polymer, and the first polymer is a polymer containing epoxy groups; S2: Mix the first polymer with a double long-chain alkylamine to cause the epoxy groups in the first polymer to undergo a ring-opening reaction with the secondary amino groups in the double long-chain alkylamine to form a second polymer. The molecular structure of the second polymer contains hydroxyl groups and amino groups; S3: React the second polymer with a monocarboxyl silicone oil to form a third polymer S4: React the third polymer with an organic acid to form a mixture containing a fourth polymer. The organic acid is a mixture of one or more of formic acid, acetic acid and propionic acid; S5: Post-treat the mixture.

2. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 1, characterized in that, The initiator solution is obtained by dissolving benzoyl peroxide in diethylene glycol butyl ether.

3. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 1, characterized in that, The double long-chain alkylamine is ditetradecylamine.

4. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 1, characterized in that, The monocarboxyl silicone oil is BY16-880.

5. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 4, characterized in that, Step S3 is: Add BY16-880 to a container containing the second polymer and stir to react.

6. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 5, characterized in that, Step S2 is: Cool the mixture containing the first polymer to 80 °C, slowly add ditetradecylamine, and then keep it warm for reaction.

7. The preparation method of the cationic polyacrylate waterproofing agent dispersion according to claim 6, characterized in that, The step of post-treating the mixture is: Add ionic water and emulsify and disperse it at high speed.

8. A cationic polyacrylate waterproofing agent dispersion, characterized in that, Prepared by the method according to any one of claims 1-7.

Images