Polyacrylate emulsion for water-based polypropylene engineering plastic paint and preparation method

Abstract

The present disclosure discloses a polyacrylate emulsion for water-based polypropylene engineering plastic paint and a preparation method, belonging to the field of acrylic resin technology. The polyacrylate emulsion includes: 0.05-1 parts by mass of dioctyl sodium sulfosuccinate; 0.05-1 parts by mass of allyl-containing alkyl alcohol ether sulfate; 1-4 parts by mass of acrylic polyether phosphate; 38-42 parts by mass of butyl methacrylate; 1-4 parts by mass of hydroxypropyl methacrylate; 0.1-1 parts by mass of acrylic acid; 0.1-1 parts by mass of methacrylic acid; 0.1-1 parts by mass of dodecanethiol; 0.02-0.5 parts by mass of ammonium persulfate; 1-3 parts by mass of chlorinated polypropylene emulsion; and 45-55 parts by mass of deionized water. The present disclosure forms a polyacrylate emulsion with good stability, water resistance, solvent resistance, and binding properties by designing the ratio of reactive monomers and synergizing the reactive monomers with components such as emulsifiers and other functional additives.

Description

Technical Field

[0001] The present invention belongs to the technical field of acrylic resins, and particularly relates to a polyacrylate emulsion for water-based polypropylene engineering plastic paint and a preparation method thereof. Background Art

[0002] Oil-based paints emit a large amount of VOCs during their production and use, and cannot adapt to environmental development requirements. Therefore, it is necessary to develop other paints with low VOC emissions, such as water-based paints.

[0003] As a crucial component of water-based paint, the performance of water-based resins ultimately determines the performance of these paints. Compared to traditional solvent-based acrylic resins, water-based acrylic resins use little or no organic solvents, offering advantages such as reduced VOC emissions and environmental friendliness. Water-based industrial paints made with them also exhibit low VOC emissions and environmental friendliness during production and use. Furthermore, water-based acrylic resins exhibit excellent light, heat, and chemical stability, as well as weather resistance. Consequently, water-based acrylic resins have become a key area of acrylic resin development.

[0004] However, the water-based paints or water-based resins currently on the market generally have disadvantages such as poor water resistance, poor solvent resistance, and poor bonding with non-polar engineering plastics. At the same time, the paint film tends to turn white when exposed to water. Summary of the Invention

[0005] The present disclosure aims to solve at least one of the technical problems existing in the prior art and provides a polyacrylate emulsion for water-based polypropylene engineering plastic paint and a preparation method thereof.

[0006] In one aspect of the present disclosure, a polyacrylate emulsion for water-based polypropylene engineering plastic paint is provided, the polyacrylate emulsion comprising:

[0007] 0.05-1 parts by mass of dioctyl sodium sulfosuccinate;

[0008] 0.05-1 parts by mass of an allyl group-containing alkyl alcohol ether sulfate;

[0009] 1-4 parts by mass of acrylic polyether phosphate;

[0010] 38-42 parts by mass of butyl methacrylate;

[0011] 1-4 parts by mass of hydroxypropyl methacrylate;

[0012] 0.1-1 parts by mass of acrylic acid;

[0013] 0.1-1 parts by mass of methacrylic acid;

[0014] 0.1-1 parts by mass of dodecanethiol;

[0015] 0.02-0.5 parts by mass of ammonium persulfate;

[0016] 1-3 parts by mass of chlorinated polypropylene emulsion;

[0017] 45-55 parts by mass of deionized water.

[0018] Another aspect of the present disclosure provides a method for preparing the aforementioned polyacrylate emulsion for water-based polypropylene engineering plastic paint, the method comprising:

[0019] S110, placing a mixture of deionized water, all the acrylic polyether phosphate emulsifiers, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan in a blender and stirring for 0.1-1 hour to form a monomer pre-emulsion;

[0020] S120, dividing the ammonium persulfate initiator into two parts, and preparing a first initiator solution and a second initiator solution respectively with deionized water;

[0021] S130. Add deionized water, sodium salt of dioctyl sulfosuccinate emulsifier and allyl-containing alkyl alcohol ether sulfate emulsifier into the reactor, start stirring, and heat to a first preset temperature under nitrogen protection. Add the monomer pre-emulsion into the reactor for the first time. After the temperature stabilizes, add the first initiator solution, keep the temperature for the first preset time, start to dropwise add the monomer pre-emulsion and the second initiator solution for the second time, keep the temperature for the second preset time, add ammonia water and the remaining deionized water, keep the temperature for the third preset time, add the chlorinated polypropylene emulsion, keep the temperature for the fourth preset time, cool down, and filter.

[0022] Optionally, the ammonium persulfate initiator is divided into two parts, and the first initiator solution and the second initiator solution are prepared with deionized water respectively, comprising:

[0023] Ammonium persulfate is divided into two equal parts, one part is dissolved in 1-2% deionized water to prepare a first initiator solution, and the other part is dissolved in 9-12% deionized water to prepare a second initiator solution.

[0024] Optionally, in step S110, the content of deionized water is 15-18% of the total amount; and / or,

[0025] In step S130, the content of deionized water is 60-65% of the total amount.

[0026] Optionally, the content of the monomer pre-emulsion added to the reactor for the first time is 3-8% of the total content;

[0027] The content of the monomer pre-emulsion added dropwise for the second time is 92-97% of the total content.

[0028] Optionally, the second dropwise addition of the monomer pre-emulsion takes 3-4 hours.

[0029] Optionally, the second initiator solution is added dropwise for 3.1-4.5 hours.

[0030] Optionally, the dripping time of the second initiator solution is 0.1-0.5 hours longer than the dripping time of the monomer pre-emulsion.

[0031] Optionally, the first preset temperature is 70-85°C.

[0032] Optionally, the first preset time is 0.1-0.5 hours; and / or,

[0033] The second preset time is 1-2 hours; and / or,

[0034] The third preset time and the fourth preset time are 0.5-1 hour.

[0035] The present disclosure provides a polyacrylate emulsion for water-based polypropylene engineering plastic paint and a preparation method. The polyacrylate emulsion comprises: 0.05-1 parts by mass of dioctyl sodium sulfosuccinate; 0.05-1 parts by mass of allyl-containing alkyl alcohol ether sulfate; 1-4 parts by mass of acrylic polyether phosphate; 38-42 parts by mass of butyl methacrylate; 1-4 parts by mass of hydroxypropyl methacrylate; 0.1-1 parts by mass of acrylic acid; 0.1-1 parts by mass of methacrylic acid; 0.1-1 parts by mass of dodecanethiol; 0.02-0.5 parts by mass of ammonium persulfate; 1-3 parts by mass of chlorinated polypropylene emulsion; and 45-55 parts by mass of deionized water. The present disclosure forms a polyacrylate emulsion with excellent stability, water resistance, solvent resistance, and bonding properties by designing the ratio of reactive monomers and synergizing the reactive monomers with components such as emulsifiers and other functional additives. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flowchart of a method for preparing a polyacrylate emulsion for water-based polypropylene engineering plastic paint according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0038] In one aspect of the present disclosure, a polyacrylate emulsion for water-based polypropylene engineering plastic paint is provided, comprising: 0.05-1 parts by mass of dioctyl sodium sulfosuccinate; 0.05-1 parts by mass of allyl-containing alkyl alcohol ether sulfate; 1-4 parts by mass of acrylic acid polyether phosphate; 38-42 parts by mass of butyl methacrylate; 1-4 parts by mass of hydroxypropyl methacrylate; 0.1-1 parts by mass of acrylic acid; 0.1-1 parts by mass of methacrylic acid; 0.1-1 parts by mass of dodecanethiol; 0.02-0.5 parts by mass of ammonium persulfate; 1-3 parts by mass of chlorinated polypropylene emulsion; and 45-55 parts by mass of deionized water, with a total of 100 parts.

[0039] In the present embodiment, dioctyl sodium sulfosuccinate, allyl-containing alkyl alcohol ether sulfate and acrylic acid polyether phosphate are used as emulsifiers at the same time. Wherein, dioctyl sodium sulfosuccinate is used as a non-reactive emulsifier, and has good emulsification. At the same time, compared with common emulsifiers, its molecular chain is longer, its molecular weight is larger, and its dosage is smaller, which can greatly reduce the water whitening phenomenon of the paint film. Secondly, allyl-containing alkyl alcohol ether sulfate and acrylic acid polyether phosphate are used as reactive emulsifiers, containing double bonds and allyl reactive groups. They participate in the reaction like reactive monomers, can better react with system monomers in the emulsion polymerization process, participate in the formation process of polymers, and are grafted onto polymer macromolecules, thereby improving the hot water resistance and solvent resistance of polymer emulsion and paint film. It will not be free when it meets water, and will produce water whitening phenomenon. That is, by the complementary effect of non-reactive and reactive emulsifiers, the stability of the emulsion is improved on the one hand, and on the other hand, the water resistance of the paint film can be effectively improved, ensuring the quality and use effect of the paint film. Thirdly, by designing the ratio of reactive monomers and synergizing the reactive monomers with components such as emulsifiers and chlorinated polypropylene emulsion additives, a polyacrylate emulsion with good stability, water resistance, solvent resistance and bonding properties is formed.

[0040] In some preferred embodiments, the content of dioctyl sodium sulfosuccinate may be preferably 0.05 parts by mass, 0.07 parts by mass, or 1 part by mass. As an important emulsifier, it has an amphiphilic structure, which enables it to be adsorbed on the oil-water interface to play a certain emulsifying role. It also has a good dispersing effect and improves wettability.

[0041] In other preferred embodiments, the content of the allyl-containing alkyl alcohol ether sulfate may preferably be 0.05 parts by mass, 0.07 parts by mass, or 1 part by mass. This component acts as a reactive emulsifier and synergistically with dioctyl sodium sulfosuccinate to improve the emulsification effect. Moreover, this component is reactive. During the emulsion polymerization process, the allyl group can participate in the polymerization reaction and react with the monomer, so that the emulsifier molecules can be covalently bonded to the polymer molecular chain to form a stable polymer emulsion, thereby improving the hot water resistance and solvent resistance of the emulsion after film formation.

[0042] It should be noted that the allyl group-containing alkyl alcohol ether sulfate of this embodiment is preferably a sodium salt or an ammonium salt. For example, when the ammonium salt is preferred, the structural formula thereof is as follows:

[0043] , n is 1-3.

[0044] In other preferred embodiments, the content of acrylic polyether phosphate may preferably be 1 part by mass, 2 parts by mass, 3 parts by mass, or 4 parts by mass. This component also acts as a reactive emulsifier, has emulsification and reactivity, and can participate in the polymerization reaction during the emulsion polymerization process, so that the emulsifier molecules can be covalently bonded to the polymer molecular chains to form a stable polymer emulsion, thereby improving the hot water and solvent resistance of the emulsion after film formation, and improving the friction resistance of the paint film.

[0045] In other preferred embodiments, the content of butyl methacrylate may be preferably 38 parts by mass, 39 parts by mass, 40 parts by mass, 41 parts by mass, or 42 parts by mass.

[0046] In other preferred embodiments, the content of hydroxypropyl methacrylate may be 1 part by mass, 2 parts by mass, 3 parts by mass, or 4 parts by mass.

[0047] In other preferred embodiments, the content of acrylic acid may be 0.1 parts by mass, 0.3 parts by mass, 0.5 parts by mass, 0.7 parts by mass, or 1 part by mass.

[0048] In other preferred embodiments, the content of methacrylic acid may be 0.1 parts by mass, 0.3 parts by mass, 0.5 parts by mass, 0.7 parts by mass, or 1 part by mass.

[0049] In this embodiment, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, and methacrylic acid are used as polymerization monomers to make the plastic paint have good hardness and glossiness.

[0050] In other preferred embodiments, the content of dodecanethiol may preferably be 0.1 parts by mass, 0.3 parts by mass, 0.5 parts by mass, 0.7 parts by mass, or 1 part by mass. This component serves as a chain transfer agent, mainly used to control the molecular weight and molecular weight distribution of the polymer so that it meets the expected performance requirements. It can react with the active polymer chain to terminate the growth of the growing polymer chain.

[0051] In other preferred embodiments, the content of ammonium persulfate may preferably be 0.02 parts by mass, 0.03 parts by mass, or 0.05 parts by mass. As an initiator, during the polymerization reaction, ammonium persulfate is heated or decomposed under appropriate reaction conditions to produce sulfate radicals, which can initiate free radical polymerization of the monomers in the emulsion to form a polymer.

[0052] In other preferred embodiments, the content of chlorinated polypropylene emulsion can be preferably 1 part by mass, 2 parts by mass, or 3 parts by mass. This component can combine with the same chemical structure in polyolefin to generate a strong interaction force, thereby improving the adhesion of the paint film to the plastic substrate in the plastic paint, improving film-forming properties, and reducing costs.

[0053] In other preferred embodiments, the content of deionized water may be preferably 45 parts by mass, 47 parts by mass, 50 parts by mass, or 55 parts by mass.

[0054] In this embodiment, the ratio of reactive monomers is designed, and functional additives and reactive emulsifiers are introduced to form an emulsion with good water resistance, solvent resistance and bonding properties. When applied to plastic paint, the paint film also has good adhesion.

[0055] As shown in FIG1 , another aspect of the present disclosure provides a method S100 for preparing the aforementioned polyacrylate emulsion for waterborne polypropylene engineering plastic paint, which specifically comprises the following steps S110 to S130:

[0056] S110, placing a mixture of deionized water, all acrylic polyether phosphate emulsifiers, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan in a blender and stirring for 0.1-1 hour to form a monomer pre-emulsion.

[0057] Specifically, in step S110 , the content of deionized water is 15-18% of the total amount of deionized water in the formula, that is, 15-18% of 45-55 parts by mass of deionized water is added to step S110 .

[0058] S120, dividing the ammonium persulfate initiator into two parts, and preparing a first initiator solution and a second initiator solution respectively with deionized water.

[0059] Specifically, ammonium persulfate is divided into two equal parts, one part is dissolved in 1-2% deionized water to prepare a first initiator solution, and the other part is dissolved in 9-12% deionized water to prepare a second initiator solution.

[0060] S130. Add deionized water, sodium salt of dioctyl sulfosuccinate emulsifier and allyl-containing alkyl alcohol ether sulfate emulsifier into the reactor, start stirring, and heat to a first preset temperature under nitrogen protection. Add the monomer pre-emulsion into the reactor for the first time. After the temperature stabilizes, add the first initiator solution, keep the temperature for the first preset time, start to dropwise add the monomer pre-emulsion and the second initiator solution for the second time, keep the temperature for the second preset time, add ammonia water and the remaining deionized water, keep the temperature for the third preset time, add the chlorinated polypropylene emulsion, keep the temperature for the fourth preset time, cool down, and filter.

[0061] Furthermore, in step S130, the amount of deionized water added is 60-65% of the total amount.

[0062] Furthermore, in step S130, the monomer pre-emulsion is first added to the reactor at a content of 3-8% of the total content; and the second addition of the monomer pre-emulsion is at a content of 92-97% of the total content. In other words, the monomer pre-emulsion formed in step S110 is divided into two portions, one portion of which is 3-8% of the total content and is first added to the reaction vessel to introduce the first initiator solution for reaction. The remaining monomer pre-emulsion and the second initiator solution are then added dropwise to the reaction vessel for reaction.

[0063] Furthermore, the second dropwise addition of the monomer pre-emulsion takes 3-4 hours, and the second dropwise addition of the initiator solution takes 3.1-4.5 hours.

[0064] It should be understood that in order to make the monomers react better, the second initiator solution is added for 0.1-0.5 hours longer than the monomer pre-emulsion, so that the monomers can fully react when the initiator decomposes to release the initiating groups.

[0065] Furthermore, the first preset temperature is 70-85°C, for example, 70°C, 75°C, 80°C, 85°C, etc.

[0066] Furthermore, the first preset time is 0.1-0.5 hours, for example, 0.1 hours, 0.2 hours, 0.3 hours, 0.4 hours, 0.5 hours, etc.

[0067] Furthermore, the second preset time is 1-2 hours, for example, 1 hour, 1.5 hours, 2 hours, etc.

[0068] Furthermore, the third preset time and the fourth preset time are both 0.5-1 hour, for example, 0.5 hour, 0.7 hour, 1 hour, etc.

[0069] The present invention optimizes the emulsifier components and preparation process parameters to enable the components to work synergistically to form a polyacrylate emulsion with good water resistance, solvent resistance and bonding properties. The preparation method is simple.

[0070] The water-based polypropylene engineering plastic paint formed in this embodiment has good water resistance and solvent resistance, strong bonding with non-polar engineering plastics, and is not prone to whitening of the paint film when exposed to water.

[0071] The polyacrylate emulsion and its preparation method will be further described below with reference to specific examples:

[0072] Example 1

[0073] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0074] 0.2 parts of dioctyl sodium sulfosuccinate

[0075] 0.25 parts of allyl-containing alkyl alcohol ether sulfate

[0076] 2.5 parts of acrylic polyether phosphate

[0077] 40 parts of butyl methacrylate

[0078] 2 parts of hydroxypropyl methacrylate

[0079] 0.5 parts of acrylic acid

[0080] 0.5 parts of methacrylic acid

[0081] 0.2 parts of dodecanethiol

[0082] 0.1 part ammonium persulfate

[0083] 1 part chlorinated polypropylene emulsion

[0084] 52.75 parts deionized water

[0085] A total of 100 copies.

[0086] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0087] .

[0088] Furthermore, the preparation method comprises:

[0089] (1) Monomer pre-emulsion

[0090] Take 16% of the total amount of deionized water in the above formula, i.e. 8.44 parts, all the acrylic polyether phosphate emulsifier, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan to form a mixture, put it into a blender and stir for 0.5 hours to prepare a monomer pre-emulsion for later use;

[0091] (2) Preparation of initiator solution

[0092] The ammonium persulfate initiator was evenly divided into two parts, one part was dissolved in 1.4% of the total amount of deionized water, i.e., 0.7358 parts, to prepare a first initiator solution, and the other part was dissolved in 10% of the total amount of deionized water, i.e., 5.275 parts, to prepare a second initiator solution for later use;

[0093] (3) Shell emulsion synthesis process

[0094] Take 64% of the total amount of deionized water, i.e. 33.76 parts, all the dioctyl sodium salt of sulfosuccinate emulsifier and all the allyl-containing alkyl alcohol ether sulfate emulsifier, add them to a reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 80°C under nitrogen protection, take 4% of the monomer pre-emulsion and add it to the reactor, after the temperature stabilizes, add the first initiator solution, keep warm and react for 0.5 hour, start adding the remaining monomer pre-emulsion and the second initiator solution simultaneously, the addition time is controlled to 3 hours, and the initiator is added for 0.3 hour longer than the monomer pre-emulsion. After the addition is complete, keep warm and react for 1 hour, add ammonia water and the remaining water, keep warm for 0.5 hour, add all the chlorinated polypropylene emulsion, keep warm for 0.5 hour, cool and filter.

[0095] Furthermore, the emulsion obtained in Example 1 was used as a polypropylene engineering plastic varnish. After testing, the properties of the paint film are shown in Table 1. The hardness was H-HB level, and there was no whitening under the conditions of immersion in hot water at 40°C for 15 days, immersion in hot water at 70°C for 4 hours, and immersion in hot water at 100°C for 1 hour. The adhesion was level 5, indicating that the paint film within the grid did not fall off at all, and the bonding force between the paint film and the substrate was very strong, which may be due to the formation of good chemical bonding, physical adsorption, or mechanical bite between the paint film and the substrate.

[0096] Example 2

[0097] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0098] 0.8 parts of dioctyl sodium sulfosuccinate

[0099] 0.7 parts of allyl-containing alkyl alcohol ether sulfate

[0100] 1.5 parts of acrylic polyether phosphate

[0101] 38 parts of butyl methacrylate

[0102] 4 parts of hydroxypropyl methacrylate

[0103] 0.5 parts of acrylic acid

[0104] 0.5 parts of methacrylic acid

[0105] 0.8 parts of dodecanethiol

[0106] 0.5 parts of ammonium persulfate

[0107] 3 parts of chlorinated polypropylene emulsion

[0108] 49.7 parts deionized water

[0109] A total of 100 copies.

[0110] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0111] .

[0112] Furthermore, the preparation method comprises:

[0113] (1) Monomer pre-emulsion

[0114] A mixture of 16% (7.952 parts) of the total amount of deionized water in the above formula, all of the acrylic polyether phosphate emulsifier, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan was placed in a blender and stirred for 0.5 hours to prepare a monomer pre-emulsion for later use;

[0115] (2) Preparation of initiator solution

[0116] The ammonium persulfate initiator was divided into two equal parts, one part was dissolved in 1.4% of the total amount of deionized water, i.e., 0.696 parts, to prepare a first initiator solution, and the other part was dissolved in 10% of the total amount of deionized water, i.e., 4.97 parts, to prepare a second initiator solution for later use;

[0117] (3) Shell emulsion synthesis process

[0118] Take 64% of the total amount of deionized water, i.e. 31.808 parts, all the dioctyl sodium salt of sulfosuccinate emulsifier and all the allyl-containing alkyl alcohol ether sulfate emulsifier, add them to a reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 80°C under nitrogen protection, take 4% of the monomer pre-emulsion and add it to the reactor, after the temperature stabilizes, add the first initiator solution, keep warm and react for 0.5 hour, start adding the remaining monomer pre-emulsion and the second initiator solution simultaneously, the addition time is controlled to 3 hours, and the initiator is added for 0.3 hour longer than the monomer pre-emulsion. After the addition is complete, keep warm and react for 1 hour, add ammonia water and the remaining water, keep warm for 0.5 hour, add all the chlorinated polypropylene emulsion, keep warm for 0.5 hour, cool and filter.

[0119] Furthermore, the emulsion obtained in Example 2 was used as a polypropylene engineering plastic varnish. After testing, the properties of the paint film are shown in Table 1. The hardness was H-HB level, and there was no whitening under the conditions of immersion in hot water at 40°C for 15 days, immersion in hot water at 70°C for 4 hours, and immersion in hot water at 100°C for 1 hour. The adhesion was level 5, indicating that the paint film within the grid did not fall off at all, and the bonding force between the paint film and the substrate was very strong, which may be due to the formation of good chemical bonding, physical adsorption, or mechanical bite between the paint film and the substrate.

[0120] Example 3

[0121] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0122] 0.2 parts of dioctyl sodium sulfosuccinate

[0123] 0.25 parts of allyl-containing alkyl alcohol ether sulfate

[0124] 2.5 parts of acrylic polyether phosphate

[0125] 40 parts of butyl methacrylate

[0126] 2 parts of hydroxypropyl methacrylate

[0127] 0.5 parts of acrylic acid

[0128] 0.5 parts of methacrylic acid

[0129] 0.2 parts of dodecanethiol

[0130] 0.1 part ammonium persulfate

[0131] 1 part chlorinated polypropylene emulsion

[0132] 52.75 parts deionized water

[0133] A total of 100 copies.

[0134] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0135] .

[0136] Furthermore, the preparation method comprises:

[0137] (1) Monomer pre-emulsion

[0138] Take 18% of the total amount of deionized water in the above formula, i.e. 9.495 parts, all the acrylic polyether phosphate emulsifier, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan to form a mixture, put it into a blender and stir for 0.5 hours to prepare a monomer pre-emulsion for later use;

[0139] (2) Preparation of initiator solution

[0140] The ammonium persulfate initiator was evenly divided into two parts, one part was dissolved in 2% of the total amount of deionized water, i.e., 1.055 parts, to prepare a first initiator solution, and the other part was dissolved in 12% of the total amount of deionized water, i.e., 6.33 parts, to prepare a second initiator solution for later use;

[0141] (3) Shell emulsion synthesis process

[0142] Take 61% of the total amount of deionized water, i.e. 32.177 parts, all the dioctyl sodium salt of sulfosuccinate emulsifier and all the allyl-containing alkyl alcohol ether sulfate emulsifier, add them to a reactor with nitrogen protection, heating, stirring and condensation reflux, start stirring, heat to 80°C under nitrogen protection, take 6% of the monomer pre-emulsion and add it to the reactor, after the temperature stabilizes, add the first initiator solution, keep warm and react for 0.5 hour, start adding the remaining monomer pre-emulsion and the second initiator solution simultaneously, the addition time is controlled within 3 hours, and the initiator is added for 0.3 hour longer than the monomer pre-emulsion. After the addition is complete, keep warm and react for 1 hour, add ammonia water and the remaining water, keep warm for 0.5 hour, add all the chlorinated polypropylene emulsion, keep warm for 0.5 hour, cool and filter.

[0143] Furthermore, the emulsion obtained in Example 3 was used as a polypropylene engineering plastic varnish. After testing, the properties of the paint film are shown in Table 1. The hardness was H-HB level, and there was no whitening under the conditions of immersion in hot water at 40°C for 15 days, immersion in hot water at 70°C for 4 hours, and immersion in hot water at 100°C for 1 hour. The adhesion was level 5, indicating that the paint film within the grid did not fall off at all, and the bonding force between the paint film and the substrate was very strong, which may be due to the formation of good chemical bonding, physical adsorption, or mechanical bite between the paint film and the substrate.

[0144] Example 4

[0145] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0146] 0.2 parts of dioctyl sodium sulfosuccinate

[0147] 0.25 parts of allyl-containing alkyl alcohol ether sulfate

[0148] 2.5 parts of acrylic polyether phosphate

[0149] 40 parts of butyl methacrylate

[0150] 2 parts of hydroxypropyl methacrylate

[0151] 0.5 parts of acrylic acid

[0152] 0.5 parts of methacrylic acid

[0153] 0.2 parts of dodecanethiol

[0154] 0.1 part ammonium persulfate

[0155] 1 part chlorinated polypropylene emulsion

[0156] 52.75 parts deionized water

[0157] A total of 100 copies.

[0158] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0159] .

[0160] Furthermore, the preparation method comprises:

[0161] (1) Monomer pre-emulsion

[0162] Take 16% of the total amount of deionized water in the above formula, i.e. 8.44 parts, all the acrylic polyether phosphate emulsifier, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan to form a mixture, put it into a blender and stir for 0.5 hours to prepare a monomer pre-emulsion for later use;

[0163] (2) Preparation of initiator solution

[0164] The ammonium persulfate initiator was divided into two equal parts, one part was dissolved in 1.4% of the total amount of deionized water, i.e., 0.7385 parts, to prepare a first initiator solution, and the other part was dissolved in 10% of the total amount of deionized water, i.e., 5.275 parts, to prepare a second initiator solution for later use;

[0165] (3) Shell emulsion synthesis process

[0166] Take 64% of the total amount of deionized water, i.e. 33.76 parts, all the dioctyl sodium salt of sulfosuccinate emulsifier and all the allyl-containing alkyl alcohol ether sulfate emulsifier, and add them to a reactor with nitrogen protection, heating, stirring and condensation reflux. Start stirring and heat to 78°C under nitrogen protection. Take 4% of the monomer pre-emulsion and add it to the reactor. After the temperature stabilizes, add the first initiator solution and keep it warm for 0.1 hour. Start adding the remaining monomer pre-emulsion and the second initiator solution at the same time. The addition time is controlled to 4 hours. The initiator is added for 0.5 hour longer than the monomer pre-emulsion. After the addition is complete, keep it warm for 2 hours. Add ammonia water and the remaining water and keep it warm for 1 hour. Add all the chlorinated polypropylene emulsion and keep it warm for 1 hour. Cool and filter.

[0167] Furthermore, the emulsion obtained in Example 4 was used as a polypropylene engineering plastic varnish. After testing, the properties of the paint film are shown in Table 1. The hardness was H-HB level, and there was no whitening under the conditions of immersion in hot water at 40°C for 15 days, immersion in hot water at 70°C for 4 hours, and immersion in hot water at 100°C for 1 hour. The adhesion was level 5, indicating that the paint film within the grid did not fall off at all, and the bonding force between the paint film and the substrate was very strong, which may be due to the formation of good chemical bonding, physical adsorption, or mechanical bite between the paint film and the substrate.

[0168] Comparative Example 1

[0169] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0170] 2.95 parts of dioctyl sodium sulfosuccinate

[0171] 40 parts of butyl methacrylate

[0172] 2 parts of hydroxypropyl methacrylate

[0173] 0.5 parts of acrylic acid

[0174] 0.5 parts of methacrylic acid

[0175] 0.2 parts of dodecanethiol

[0176] 0.1 part ammonium persulfate

[0177] 1 part chlorinated polypropylene emulsion

[0178] 52.75 parts deionized water

[0179] A total of 100 copies.

[0180] Furthermore, the emulsion of Comparative Example 1 was prepared using the same method as Example 1, and the resulting emulsion was used as a polypropylene engineering plastic varnish. Testing revealed the properties of the paint film, as shown in Table 1. The hardness was H-HB, and whitening occurred after immersion in hot water at 40°C for 15 days, 70°C for 4 hours, and 100°C for 1 hour. The adhesion was grade 3, indicating decreased adhesion. This indicates that, while a single sodium salt of dioctyl sulfosuccinate can be used as the emulsifier, the polyacrylate emulsion can be stably prepared, but its water resistance is significantly reduced.

[0181] Comparative Example 2

[0182] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0183] 0.45 parts of allyl-containing alkyl alcohol ether sulfate

[0184] 2.5 parts of acrylic polyether phosphate

[0185] 40 parts of butyl methacrylate

[0186] 2 parts of hydroxypropyl methacrylate

[0187] 0.5 parts of acrylic acid

[0188] 0.5 parts of methacrylic acid

[0189] 0.2 parts of dodecanethiol

[0190] 0.1 part ammonium persulfate

[0191] 1 part chlorinated polypropylene emulsion

[0192] 52.75 parts deionized water

[0193] A total of 100 copies.

[0194] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0195] .

[0196] Furthermore, the emulsion preparation method of this comparative example 2 is the same as that of Example 1. Demulsification occurs during the synthesis process, and the target polyacrylate emulsion cannot be prepared normally, indicating that the allyl-containing alkyl alcohol ether sulfate and acrylic polyether phosphate have poor emulsification properties, and the dioctyl sodium salt of sulfosuccinate has good emulsification properties. Combining Examples 1-4 and Comparative Examples 1-2, the dioctyl sodium salt of sulfosuccinate and the allyl-containing alkyl alcohol ether sulfate and acrylic polyether phosphate have a synergistic effect, providing emulsification stability and water resistance.

[0197] Comparative Example 3

[0198] A polyacrylate emulsion for water-based polypropylene engineering plastic paint, the raw material components of which are as follows by weight:

[0199] 0.2 parts of dioctyl sodium sulfosuccinate

[0200] 0.25 parts of allyl-containing alkyl alcohol ether sulfate

[0201] 2.5 parts of acrylic polyether phosphate

[0202] 40 parts of butyl methacrylate

[0203] 2 parts of hydroxypropyl methacrylate

[0204] 0.5 parts of acrylic acid

[0205] 0.5 parts of methacrylic acid

[0206] 0.2 parts of dodecanethiol

[0207] 0.1 part ammonium persulfate

[0208] 53.75 parts deionized water

[0209] A total of 100 copies.

[0210] Among them, the allyl-containing alkyl alcohol ether sulfate was purchased from Japan Aidi Co., Ltd., SR-1025, and its structural formula is as follows:

[0211] .

[0212] Furthermore, the emulsion preparation method of Comparative Example 3 was the same as that of Example 1, and the resulting emulsion was used as a polypropylene engineering plastic varnish. Testing revealed that the properties of the paint film are shown in Table 1: hardness was H-HB, no whitening occurred after immersion in 40°C hot water for 15 days, 70°C hot water for 4 hours, and 100°C hot water for 1 hour, and adhesion was grade 4. This demonstrates that the chlorinated polypropylene emulsion can enhance the adhesion of the paint film to the plastic substrate and improve film-forming properties.

[0213] Table 1 Test results of paint film properties of various embodiments and comparative examples

[0214]

[0215] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A method for preparing a polyacrylate emulsion for water-based polypropylene engineering plastic paint, characterized in that: The method comprises: S110, placing a mixture of deionized water, all acrylic polyether phosphate emulsifiers, butyl methacrylate, hydroxypropyl methacrylate, acrylic acid, methacrylic acid, and dodecyl mercaptan in a blender and stirring for 0.1-1 hour to form a monomer pre-emulsion; wherein, The content of deionized water is 15-18% of the total amount, and the total content of deionized water is 45-55 parts by mass; the content of acrylic acid polyether phosphate is 1-4 parts by mass; the content of butyl methacrylate is 38-42 parts by mass; the content of hydroxypropyl methacrylate is 1-4 parts by mass; the content of acrylic acid is 0.1-1 part by mass; the content of methacrylic acid is 0.1-1 part by mass; and the content of dodecanethiol is 0.1-1 part by mass. S120, dividing the ammonium persulfate initiator into two parts, and preparing a first initiator solution and a second initiator solution respectively with deionized water; wherein, The content of ammonium persulfate is 0.02-0.5 parts by mass, which is divided into two parts, one part is dissolved in 1-2% deionized water to prepare a first initiator solution, and the other part is dissolved in 9-12% deionized water to prepare a second initiator solution; S130, adding deionized water, sodium salt of dioctyl sulfosuccinate emulsifier and allyl-containing alkyl alcohol ether sulfate emulsifier to a reactor, starting stirring, heating to a first preset temperature of 70-85° C. under nitrogen protection, adding the monomer pre-emulsion to the reactor for the first time, adding the first initiator solution after the temperature stabilizes, keeping the temperature for the first preset time, starting to dropwise add the monomer pre-emulsion and the second initiator solution for the second time, the second initiator solution dropping time is 3.1-4.5 hours, the second initiator solution dropping time is 0.1-0.5 hours longer than the monomer pre-emulsion dropping time, keeping the temperature for the second preset time, adding ammonia water and the remaining deionized water, keeping the temperature for a third preset time, adding the chlorinated polypropylene emulsion, keeping the temperature for a fourth preset time, cooling, and filtering; wherein, In step S130, the amount of deionized water used is 68-75% of the total amount; the content of dioctyl sodium salt of sulfosuccinate emulsifier is 0.05-1 parts by mass; the content of allyl-containing alkyl alcohol ether sulfate emulsifier is 0.05-1 parts by mass, and the allyl-containing alkyl alcohol ether sulfate emulsifier is an ammonium salt represented by the following structural formula: ; The content of chlorinated polypropylene emulsion is 1-3 parts by mass.

2. The method according to claim 1, characterized in that The content of the monomer pre-emulsion added to the reactor for the first time is 3-8% of its total content; The content of the monomer pre-emulsion added dropwise for the second time is 92-97% of the total content.

3. The method according to claim 1, characterized in that The time for the second dropwise addition of the monomer pre-emulsion is 3-4 hours.

4. The method according to claim 1, wherein The first preset time is 0.1-0.5 hours; and / or, The second preset time is 1-2 hours; and / or, The third preset time and the fourth preset time are 0.5-1 hour.

5. A polyacrylate emulsion for water-based polypropylene engineering plastic paint, characterized in that: The water-based polypropylene engineering plastic paint polyacrylate emulsion is prepared according to the method according to any one of claims 1 to 4.

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