Acrylic emulsion for high-toughness paper mat and preparation method thereof

Abstract

The invention belongs to the technical field of emulsion synthesis, and relates to an acrylic emulsion for a high-flexibility paper mat and a preparation method of the acrylic emulsion, and the formula components of the acrylic emulsion comprise a monomer component, an emulsifier, an initiator, an auxiliary agent, a pH regulator and water, the monomer component comprises methyl methacrylate, butyl acrylate, styrene, acrylic acid, polyethylene glycol 400 diacrylate and acrylamide, and the emulsifier comprises lauryl sodium sulfate. The Z particle size of the acrylic emulsion obtained through the scheme is smaller than 55 nm, when the acrylic emulsion is used as a coating, glossiness is high, a mat surface is bright, the mat surface is stiff and smooth, meanwhile, the folding performance is good, and the coating is kept intact after the acrylic emulsion is folded for one hundred times or a heavy object is pressed for 24 hours after the acrylic emulsion is folded.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsion synthesis and relates to an acrylic emulsion for high-toughness paper mats and a preparation method thereof. Background Art

[0002] Traditional mats are made of straw, but because straw is not easy to grow, they are now mostly replaced by artificially produced paper mats. Paper mats are made of cotton yarn as the core, wrapped with thin paper, woven, sprayed, hot-pressed, and finally bonded to the base fabric. The sprayed coating is generally acrylic emulsion. The acrylic coating can fix the warp and weft yarns of the paper mat, so that the paper mat has a certain degree of stiffness and is flat, straight and beautiful, and also makes the paper mat have a certain degree of flexibility so that it can be rolled up and folded for storage. The water resistance of the acrylic coating also protects the paper yarn that is very easy to absorb moisture and water, so that the paper mat has a longer service life. The existing paper mats processed by acrylic emulsion have the main problem of not being foldable, and are generally rolled up for storage or carrying. If folded many times, or heavy objects are placed on top after folding, the coating will be damaged at the crease. If the glass transition temperature of the emulsion is lowered, the flexibility of the coating is improved, but the strength of the coating is reduced, and the stiffness of the mat is poor. The hardness and toughness of the coating have always been a big problem in the paper mat industry. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an acrylic emulsion for paper mats with high toughness that meets the requirements of both stiffness and flexibility of paper mats by adjusting and optimizing the components of the acrylic emulsion and adding special monomers.

[0004] To achieve the above object, the present invention adopts the following technical solutions: An acrylic emulsion for high-toughness paper mats is characterized in that it is made of the following raw materials in percentage by weight: 9-20% of methyl methacrylate, 2-10% of styrene, 7-10% of butyl acrylate, 1-1.5% of acrylic acid, 0.5-1.5% of acrylamide, 1-1.5% of polyethylene glycol 400 diacrylate, 0.6-1.2% of anionic emulsifier, 0.1-0.2% of initiator, 0.5-2% of ammonia water, 1-2% of brightener, 0.1-0.3% of defoamer, 0.01-0.05% of bactericide and the balance of deionized water.

[0005] Preferably, the anionic emulsifier is sodium lauryl sulfate.

[0006] Preferably, the initiator is ammonium persulfate or potassium persulfate.

[0007] Preferably, the brightener is a wax emulsion or a high molecular weight silicone oil emulsion or a mixture of a wax emulsion and a high molecular weight silicone oil emulsion.

[0008] Preferably, the fungicide is Kathon fungicide.

[0009] Preferably, the defoamer is a mineral oil defoamer or a silicone defoamer.

[0010] Another object of the present invention is to provide a method for preparing an acrylic emulsion for high-toughness paper mats.

[0011] To achieve the above object, the present invention adopts the following technical solutions: A method for preparing an acrylic emulsion for high-toughness paper mats, which is characterized by comprising the following steps: (1) Add an emulsifier and deionized water to a reaction device and heat to 80 - 83°C; (2) Dissolve acrylamide in water to obtain a solution, and add polyethylene glycol 400 diacrylate and mix evenly; (3) Dissolve 30% - 50% of the total amount of initiator in water to obtain a solution; (4) Mix methyl methacrylate, butyl acrylate, styrene, and acrylic acid evenly to obtain a monomer mixture; (5) After the temperature of the reaction device in step 1 reaches 80 - 83°C, add the remaining initiator, and start dropping the liquids obtained in steps (2), (3), and (4). Finish dropping in 3 - 3.5 hours. After dropping, keep warm for 2 hours. After the heat preservation ends, start cooling. When the temperature drops below 40°C, add a defoamer, ammonia water, a brightening agent, and a fungicide in sequence. After filtration, an acrylic emulsion for paper mats is obtained.

[0012] Preferably, the Z-average particle size of the acrylic emulsion for paper mats is less than 55 nm.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The acrylic emulsion for high-flexibility paper mats of the present invention has a suitable glass transition temperature and a suitable crosslinking degree by adding a special monomer polyethylene glycol 400 diacrylate. While the paper mat maintains good stiffness, it has good flexibility. After the paper mat is repeatedly folded and weighted and stacked, the coating at the crease is not damaged; (2) The acrylic emulsion for high-flexibility paper mats of the present invention has a Z-average particle size below 55 nm, the emulsion is transparent, and the coating has a very high gloss. Specific embodiments

[0014] To better illustrate the present invention and facilitate understanding of the technical solutions of the present invention, the present invention is further described in detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of the patent protection of the present invention. The scope of protection of the present invention is subject to the claims.

[0015] The present invention relates to an acrylic emulsion for high-toughness paper mats. The formulation components of the acrylic emulsion include a monomer component, an emulsifier, an initiator, ammonia water, a brightener, an antifoaming agent, a bactericide, and water. The monomer component includes methyl methacrylate, butyl acrylate, styrene, acrylic acid, acrylamide, and polyethylene glycol 400 diacrylate. The emulsifier includes sodium dodecyl sulfate. The initiator includes ammonium persulfate and / or potassium persulfate. The pH regulator includes ammonia water. The brightener includes a wax emulsion and / or a large-molecular-weight silicone oil emulsion. The antifoaming agent includes a mineral oil antifoaming agent and / or a silicone antifoaming agent. The bactericide includes Kathon.

[0016] In the present invention, for the selection of components of the acrylic emulsion, the main part is the acrylic monomer component, and the basic components are methyl methacrylate and butyl acrylate. Styrene is added to improve the brightness of the film formation. Acrylamide is added to increase the viscosity of the emulsion and reduce the penetration of the emulsion into paper fibers. Polyethylene glycol 400 diacrylate is added to improve the flexibility of the coating. In the present invention, sodium dodecyl sulfate is selected as the emulsifier, and an emulsion with a Z-average particle size of less than 55 nm can be prepared, and the gloss of the coating is relatively high. In the present invention, a wax emulsion and / or a large-molecular-weight silicone oil emulsion is selected as the brightener, which can form an isolation film layer during the high-temperature hot pressing and shaping of the paper mat, avoid the sticking plate phenomenon, and make the coating smoother and more beautiful. Example 1

[0017] A preparation method of an acrylic emulsion for high-flexibility paper mats includes the following steps: (1) Add 10.15 g of sodium dodecyl sulfate as the emulsifier and 505.51 g of deionized water to the reaction device and heat to 80 - 83 °C; (2) Dissolve 12.18 g of acrylamide in 109.62 g of water to obtain a solution, add 10.15 g of polyethylene glycol 400 diacrylate, and stir evenly; (3) Dissolve 0.28 g of ammonium persulfate as the initiator in 47 g of water to obtain a solution; (4) Mix 157.4 g of methyl methacrylate, 78.37 g of butyl acrylate, 20.3 g of styrene, and 11.6 g of acrylic acid evenly to obtain a monomer mixture; (5) After the temperature of the reaction device in step 1 reaches 80 - 83 °C, add 0.87 g of ammonium persulfate as the initiator, and start to dropwise add the liquids in steps (2), (3), and (4). Finish dropping in 3 - 3.5 hours. After dropping, keep the temperature for 2 hours. After the heat preservation ends, start to cool down. When the temperature drops below 40 °C, add the antifoaming agent, ammonia water, brightener, and Kathon in sequence, and mix evenly to obtain the acrylic emulsion for high-flexibility paper mats. After testing, the Z-average particle size of the acrylic emulsion for paper mats is 52.65 nm, and the 60° gloss is 88%. Example 2

[0018] A preparation method of an acrylic emulsion for paper mats, comprising the following steps: (1) Add 9.44 g of emulsifier sodium dodecyl sulfate and 503.51 g of deionized water to a reaction device and heat to 80 - 83 °C; (2) Dissolve 11.8 g of acrylamide in 106.2 g of water to obtain a solution, add 11.8 g of polyethylene glycol 400 diacrylate, and stir evenly; (3) Dissolve 0.59 g of initiator ammonium persulfate in 47.84 g of water to obtain a solution; (4) Mix 162.04 g of methyl methacrylate, 77.79 g of butyl acrylate, 20.65 g of styrene, and 11.8 g of acrylic acid evenly to obtain a monomer mixture; (5) After the temperature of the reaction device in step (1) reaches 80 - 83 °C, add 1.18 g of initiator ammonium persulfate, and start to dropwise add the liquids in steps (2), (3), and (4). Finish dropping in 3 - 3.5 hours. After dropping, keep warm for 2 hours. After the heat preservation ends, start to cool down. When the temperature drops below 40 °C, add defoamer, ammonia water, wax emulsion, and Kathon in sequence and mix evenly to obtain the acrylic emulsion for paper mats. After testing, the Z-average particle size of the acrylic emulsion for paper mats is 51.66 nm, and the 60° gloss is 88%. Example 3

[0019] A preparation method of an acrylic emulsion for paper mats, which comprises the following steps: (1) Add 10.08 g of emulsifier sodium dodecyl sulfate and 513.19 g of deionized water to a reaction device and heat to 80 - 83 °C; (2) Dissolve 12.6 g of acrylamide in 113.4 g of water to obtain a solution; (3) Dissolve 0.56 g of initiator ammonium persulfate in 113.4 g of water to obtain a solution, add 11.2 g of polyethylene glycol 400 diacrylate, and stir evenly; (4) Mix 93.08 g of methyl methacrylate, 73.52 g of butyl acrylate, 75.6 g of styrene, and 14 g of acrylic acid evenly to obtain a monomer mixture; (5) After the temperature of the reaction device in step (1) reaches 80 - 83 °C, add 1.12 g of initiator ammonium persulfate, and start to dropwise add the liquids in steps (2), (3), and (4). Finish dropping in 3 - 3.5 hours. After dropping, keep warm for 2 hours. After the heat preservation ends, start to cool down. When the temperature drops below 40 °C, add defoamer, ammonia water, wax emulsion, and Kathon in sequence and mix evenly to obtain the acrylic emulsion for paper mats. After testing, the Z-average particle size of the acrylic emulsion for paper mats is 54.32 nm, and the 60° gloss is 89%.

[0020] The acrylic emulsions for paper mats prepared in Examples 1 - 3 were respectively sprayed onto 3 paper mats. After they were dried, they were respectively subjected to high-temperature calendering and shaping, and then folding tests were carried out. The same crease was folded 100 times, and the surface coating at the crease of the paper mat was not damaged. After the paper mat was folded, a heavy object was pressed on the crease, and the pressure was 1 kg / cm 2 . After 24 hours, the surface coating at the crease of the paper mat was not damaged.

[0021] The present invention illustrates the detailed products and methods of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed products and methods, that is, it does not mean that the present invention must rely on the above-mentioned detailed products and methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent substitution of the products of the present invention, addition of auxiliary components, selection of specific methods, etc. all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An acrylic emulsion for high-toughness paper mats, characterized in that The invention is made of the following raw materials in percentage by weight: 9-20% of methyl methacrylate, 2-10% of styrene, 7-10% of butyl acrylate, 1-1.5% of acrylic acid, 0.5-1.5% of acrylamide, 1-1.5% of polyethylene glycol 400 diacrylate, 0.6-1.2% of anionic emulsifier, 0.1-0.2% of initiator, 0.5-2% of ammonia water, 1-2% of brightener, 0.1-0.3% of defoamer, 0.01-0.05% of bactericide and the balance of deionized water.

2. The acrylic emulsion for high-toughness paper mat according to claim 1, characterized in that The anionic emulsifier is sodium lauryl sulfate.

3. The acrylic emulsion for high-toughness paper mat according to claim 1, characterized in that The initiator is ammonium persulfate or potassium persulfate.

4. The acrylic emulsion for high-toughness paper mat according to claim 1, characterized in that The brightener is wax emulsion or high molecular weight silicone oil emulsion or a mixture of wax emulsion and high molecular weight silicone oil emulsion.

5. The acrylic emulsion for high-toughness paper mat according to claim 1, characterized in that The bactericide is a Kathon bactericide.

6. The acrylic emulsion for high-toughness paper mat according to claim 1, characterized in that The defoamer is a mineral oil defoamer or an organosilicon defoamer.

7. A method for preparing an acrylic emulsion for high-toughness paper mats, characterized in that The following steps are involved: (1) Add emulsifier and deionized water into the reaction device and heat to 80-83°C; (2) Dissolve acrylamide in water to obtain a solution, add polyethylene glycol 400 diacrylate and mix well; (3) Dissolve 30%-50% of the total amount of the initiator in water to obtain a solution; (4) Evenly mix methyl methacrylate, butyl acrylate, styrene and acrylic acid to obtain a monomer mixture; (5) When the temperature of the reaction device in step 1 reaches 80-83°C, add the remaining initiator and start dripping the liquid obtained in steps (2), (3) and (4) for 3-3.5 hours. After the dripping is completed, keep the temperature for 2 hours. After the insulation is completed, start cooling. When the temperature drops below 40°C, add defoamer, ammonia water, brightener and bactericide in sequence. After filtering, obtain the acrylic emulsion for paper mat.

8. The method for preparing a high-toughness acrylic emulsion for paper mats according to claim 7, characterized in that The Z average particle size of the acrylic emulsion for paper mat is less than 55 nm.