Water-based acrylic contact adhesive emulsion, preparation method and application thereof

Abstract

The invention discloses a water-based acrylic contact adhesive emulsion, and a preparation method and application thereof, the emulsion comprises the following components: hard monomers of styrene, methacrylic acid, acrylic acid and the like, soft monomers of 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate and the like, functional monomers of hydroxyethyl acrylate, beta-acryloyloxypropionic acid and the like, and an initiator, the emulsion comprises a seed emulsion, an emulsifier, an inorganic salt, an oxidant, a reducing agent, a post-addition auxiliary agent and the like. A special process formula is adopted, the production stability and the product performance are fully balanced, the obtained emulsion is good in mechanical stability in the production process, and meanwhile the product is excellent in initial adhesion, persistent adhesion and wet adhesion performance.

Description

Technical Field

[0001] The invention relates to the technical field of water-based acrylic emulsions, and in particular to a water-based acrylic contact rubber latex, a preparation method and application thereof. Background Art

[0002] Contact glue refers to an adhesive that is applied between two adherends, dried and overlapped, and can form an adhesive with strong adhesive strength without pressure. It is mainly used to manufacture sports equipment, clothing, furniture, accessories and other shoes and leather products. It is also used to bond various parts of shoes, including soles and uppers. Acrylic contact glue has the advantages of environmental protection, low yellowing, and high cost performance. At the same time, contact glue adhesive is copolymerized by acrylic monomers, and its performance is highly adjustable.

[0003] Contact adhesives generally require high solid content, which is conducive to drying and adhesion. However, when the solid content of acrylic emulsion is more than 64%, the process viscosity will increase sharply, resulting in the inability to prepare the emulsion normally. At the same time, in order to improve the bonding performance, the glass transition temperature of the formula is generally relatively low during product design, so that the product has shear demulsification characteristics. However, in industrial production, when the shear resistance of the emulsion is poor, stable production cannot be achieved at all. Therefore, it is impossible to achieve a perfect balance between the performance and stable production of this type of product. At the same time, the bonding performance of the product cannot meet the requirements with only a low glass transition temperature. Summary of the invention

[0004] In order to solve the problems of poor wet adhesion and bonding performance of water-based acrylic contact glue and unstable industrial production, the present invention aims to provide a water-based acrylic adhesive emulsion. The emulsion using the special process formula of the present invention has high solid content, low process viscosity, wide molecular weight distribution, and stable industrial production. At the same time, when used downstream, it can be demulsified under the shearing action of roller coating construction, so that the wet adhesion and bonding performance of the emulsion are excellent, and finally a perfect balance between performance and industrial production can be achieved.

[0005] Another object of the present invention is to provide a method for preparing the aqueous acrylic contact latex.

[0006] Another object of the present invention is to provide applications of the aqueous acrylic contact latex.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] A water-based acrylic contact latex comprises the following components in parts by weight:

[0009]

[0010] In a preferred embodiment, the aqueous acrylic contact latex has a solid content of 65 wt%-67 wt% and a particle size of 300-500 nm.

[0011] In a specific embodiment, the hard monomer is selected from any one or more combinations of butyl methacrylate, acrylamide, methyl methacrylate, styrene, acrylic acid, and methacrylic acid. Preferably, the hard monomer is selected from a combination of acid monomers containing acrylic acid and / or methacrylic acid; more preferably, the acid monomers account for 18-21% of the total monomer weight.

[0012] In a specific embodiment, the soft monomer is selected from any one or more of allyl methacrylate, isooctyl acrylate, butyl acrylate, and ethyl acrylate.

[0013] In a specific embodiment, the functional monomer is selected from one or two of diacetone acrylamide, hydroxyethyl methacrylate, hydroxyethyl acrylate, and β-acryloxypropionic acid.

[0014] In a specific embodiment, the finished seed emulsion is a commercially available aqueous acrylic emulsion with a particle size of 60-120 nm and a solid content of 41-43 wt %. Preferably, the particle size of the finished seed emulsion is 90-120 nm.

[0015] In a specific embodiment, the emulsifier is any one or more combinations of COPS-1, sodium tridecyl alcohol polyoxyethylene ether sulfate, AE-07, AE-09, sodium salt of sulfonated diphenyl ether tetrapropylene derivative, polyoxyethylene polystyrene phenol ether, sodium allyl ether hydroxypropyl sulfonate, and sodium dodecyl sulfate; preferably, the emulsifier is selected from a combination containing AE-07 and / or AE-09, and more preferably, AE-07 and AE-09 emulsifiers account for 0.8-1.5% of the total monomer weight.

[0016] In a specific embodiment, the pre-emulsion auxiliary agent includes at least any one of a chain transfer agent and a buffer; preferably, the chain transfer agent is any one of n-dodecyl mercaptan and butyl mercapto, and the buffer is any one of sodium bicarbonate, sodium carbonate, and ammonia water.

[0017] In a specific embodiment, the oxidant is one or more of ammonium persulfate, sodium persulfate, tert-butyl hydroperoxide, and hydrogen peroxide.

[0018] In a specific embodiment, the reducing agent is one or more of sodium metabisulfite, isoascorbic acid, hydrosulfite, bleaching powder, and FF6.

[0019] In a specific embodiment, the inorganic salt is one or more of sodium sulfate, potassium sulfate, ammonium sulfate, sodium carbonate, and sodium bicarbonate.

[0020] In a specific embodiment, the post-addition auxiliary agent includes at least any one of a neutralizer, a defoamer, and a preservative commonly used in emulsion polymerization.

[0021] On the other hand, the method for preparing the aforementioned aqueous acrylic contact latex comprises the following steps:

[0022] (1) Add deionized water to the reaction kettle, raise the temperature to 65-95° C., and add emulsifier and finished seed emulsion to the bottom of the kettle;

[0023] (2) adding the first oxidant to the reactor at 65-95° C., preferably 1-15 minutes later, adding the pre-emulsion I and the second oxidant to the reactor dropwise, and simultaneously adding the pre-emulsion II to the pre-emulsion I at a certain speed until all the pre-emulsion is added dropwise, preferably, the total addition time is 180-360 minutes;

[0024] (3) Keep warm for 30-60 min, cool to 55-75° C., and simultaneously add optional post-treatment oxidizing agent and reducing agent dropwise, preferably for 30-60 min, and then continue to add inorganic salt solution dropwise, preferably for 20-40 min. After the addition is completed, start keeping warm. During the keeping warm process, test the product particle size. When the particle size reaches 400-430 nm, then quickly cool to below 50° C., the cooling time is required to be ≤30 min, and then add the post-addition auxiliary agent, adjust the pH to 3.0-6.5, and filter the material.

[0025] In a specific embodiment, the pre-emulsion I comprises the following composition, based on the total mass of the pre-emulsion I:

[0026]

[0027]

[0028] In a specific embodiment, the pre-emulsion II comprises the following composition, based on the total mass of the pre-emulsion II:

[0029] 10-35 parts by mass of finished seed emulsion, preferably 25-30 parts by mass;

[0030] 0.6-3 parts by mass, preferably 0.9-2.6 parts by mass, of pre-emulsion auxiliary agent;

[0031] Water: 5-15 parts by mass, preferably 5-10 parts by mass.

[0032] On the other hand, the aforementioned aqueous acrylic contact rubber latex is used in contact rubber.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The invention avoids the problems of low Tg, poor anti-shear stability and inability to industrialize production of conventional adhesive products through the ingenious design of hard monomer, soft monomer and functional monomer composition, emulsifier and added inorganic salt, and at the same time, the product has excellent initial adhesion, wet adhesion and sustained adhesion performance. DETAILED DESCRIPTION

[0035] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0036] A water-based acrylic contact latex comprises the following components in parts by weight:

[0037]

[0038]

[0039] The pre-emulsion additive includes at least one of a chain transfer agent and a buffer, and the post-addition additive includes at least one of a neutralizer, a defoamer, and a preservative commonly used in emulsion polymerization.

[0040] In a specific embodiment, the aqueous acrylic contact latex comprises the following components in parts by weight:

[0041] 140-160 parts by mass of hard monomer (e.g., 141 parts by mass, 142 parts by mass, 143 parts by mass, 144 parts by mass, 145 parts by mass, 146 parts by mass, 147 parts by mass, 148 parts by mass, 149 parts by mass, 150 parts by mass, 151 parts by mass, 152 parts by mass, 153 parts by mass, 154 parts by mass, 155 parts by mass, 156 parts by mass, 157 parts by mass, 158 parts by mass, 159 parts by mass, etc.), preferably 145-155 parts by mass;

[0042] 400-550 parts by mass of soft monomer (e.g., 410 parts by mass, 420 parts by mass, 430 parts by mass, 440 parts by mass, 450 parts by mass, 460 parts by mass, 470 parts by mass, 480 parts by mass, 490 parts by mass, 500 parts by mass, 510 parts by mass, 520 parts by mass, 530 parts by mass, 540 parts by mass, etc.), preferably 430-500 parts by mass;

[0043] 10-30 parts by mass of functional monomer (e.g., 11 parts by mass, 12 parts by mass, 13 parts by mass, 14 parts by mass, 15 parts by mass, 16 parts by mass, 17 parts by mass, 18 parts by mass, 19 parts by mass, 20 parts by mass, 21 parts by mass, 22 parts by mass, 23 parts by mass, 24 parts by mass, 25 parts by mass, 26 parts by mass, 27 parts by mass, 28 parts by mass, 29 parts by mass, etc.), preferably 15-25 parts by mass;

[0044] 20-60 parts by mass of finished seed emulsion (e.g., 22 parts by mass, 24 parts by mass, 25 parts by mass, 26 parts by mass, 28 parts by mass, 30 parts by mass, 32 parts by mass, 34 parts by mass, 35 parts by mass, 36 parts by mass, 38 parts by mass, 40 parts by mass, 42 parts by mass, 44 parts by mass, 45 parts by mass, 46 parts by mass, 48 ​​parts by mass, 50 parts by mass, 52 parts by mass, 54 parts by mass, 55 parts by mass, 56 parts by mass, 58 parts by mass, etc.), preferably 30-50 parts by mass;

[0045] 5-20 parts by mass of emulsifier (e.g., 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, 11 parts by mass, 12 parts by mass, 13 parts by mass, 14 parts by mass, 15 parts by mass, 16 parts by mass, 17 parts by mass, 18 parts by mass, 19 parts by mass, 20 parts by mass, etc.), preferably 7-18 parts by mass;

[0046] 0.5-2 parts by mass of chain transfer agent (e.g., 0.5 parts by mass, 0.6 parts by mass, 0.7 parts by mass, 0.8 parts by mass, 0.9 parts by mass, 1.0 parts by mass, 1.1 parts by mass, 1.2 parts by mass, 1.3 parts by mass, 1.4 parts by mass, 1.5 parts by mass, 1.6 parts by mass, 1.7 parts by mass, 1.8 parts by mass, 1.9 parts by mass, 2 parts by mass, etc.), preferably 0.7-1.8 parts by mass;

[0047] 0.1-1 mass part of buffer (e.g., 0.1 mass part, 0.2 mass part, 0.3 mass part, 0.4 mass part, 0.5 mass part, 0.6 mass part, 0.7 mass part, 0.8 mass part, 0.9 mass part, 1 mass part, etc.), preferably 0.2-0.8 mass part;

[0048] 2-8 parts by mass of an oxidant (e.g., 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, etc.), preferably 3-7 parts by mass;

[0049] 0.4-2 parts by mass of reducing agent (e.g., 0.4 parts by mass, 0.5 parts by mass, 0.6 parts by mass, 0.7 parts by mass, 0.8 parts by mass, 0.9 parts by mass, 1.0 parts by mass, 1.1 parts by mass, 1.2 parts by mass, 1.3 parts by mass, 1.4 parts by mass, 1.5 parts by mass, 1.6 parts by mass, 1.7 parts by mass, 1.8 parts by mass, 1.9 parts by mass, 2 parts by mass, etc.), preferably 0.5-1.5 parts by mass;

[0050] 5-10 parts by mass of an inorganic salt (e.g., 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, etc.), preferably 6-8 parts by mass;

[0051] Neutralizer 0.5-2 mass parts (for example 0.5 mass parts, 0.6 mass parts, 0.7 mass parts, 0.8 mass parts, 0.9 mass parts, 1.0 mass parts, 1.1 mass parts, 1.2 mass parts, 1.3 mass parts, 1.4 mass parts, 1.5 mass parts, 1.6 mass parts, 1.7 mass parts, 1.8 mass parts, 1.9 mass parts, 2 mass parts, etc.), preferably 0.7-1.5 mass parts;

[0052] 0.1-1 mass part of defoaming agent (for example, 0.1 mass part, 0.2 mass part, 0.3 mass part, 0.4 mass part, 0.5 mass part, 0.6 mass part, 0.7 mass part, 0.8 mass part, 0.9 mass part, 1 mass part, etc.), preferably 0.2-0.8 mass part;

[0053] 1-4 parts by mass of preservative (e.g., 1 part by mass, 1.5 parts by mass, 2 parts by mass, 2.5 parts by mass, 3 parts by mass, 3.5 parts by mass, 4 parts by mass, etc.), preferably 1.5-3.5 parts by mass;

[0054] Water: 260-340 parts by mass (e.g., 260 parts by mass, 270 parts by mass, 280 parts by mass, 290 parts by mass, 300 parts by mass, 310 parts by mass, 320 parts by mass, 330 parts by mass, 340 parts by mass, etc.), preferably 270-330 parts by mass.

[0055] The aqueous acrylic contact latex of the present invention preferably has a solid content of 65-67 wt% (eg, 65.5 wt%, 66 wt%, 66.5 wt%, etc.) and a particle size of 300-500 nm (eg, 350 nm, 400 nm, 450 nm, etc.).

[0056] The aqueous acrylic contact latex can be prepared by the conventional method of the present invention without any particular limitation, for example, by the following method, but not limited thereto.

[0057] A method for preparing a water-based acrylic contact adhesive comprises the following steps:

[0058] (1) Add deionized water to the reaction kettle, raise the temperature to 65-95° C., preferably 80-95° C., and add the emulsifier solution and the finished seed emulsion at the bottom of the kettle;

[0059] (2) Add the first oxidant solution to the reaction kettle at 65-95°C, preferably 80-95°C, 1-

[0060] After 15 minutes, preferably after 1-5 minutes, the pre-emulsion I and the second oxidant are added dropwise to the reaction kettle, and at the same time, the pre-emulsion II is added dropwise to the pre-emulsion I at a certain speed until all the pre-emulsion is added dropwise. The total addition time is 180-360 minutes, preferably 180-240 minutes;

[0061] (3) Keep warm for 30-60 min, cool to 55-75° C., preferably 70-75° C., and simultaneously drip optional post-treatment oxidant and reductant solutions for 30-60 min, then continue to drip inorganic salt solution for 20-40 min. After the dripping is completed, start keeping warm. During the keeping warm process, test the product particle size. When the particle size reaches 400-430 nm, then quickly cool to below 50° C., preferably to 40-50° C., and the cooling time is required to be ≤30 min. Then, add a neutralizer for neutralization, adjust the pH to 3.0-6.5, preferably adjust the pH to 4.5-5.5, continue to add a defoamer and a preservative, and filter the material.

[0062] In step (1) of the present invention, the emulsifier of the kettle bottom emulsifier solution is one or more of COPS-1, sodium sulfate of tridecanol polyoxyethylene ether, AE-07, AE-09, sodium salt of sulfonated diphenyl ether tetrapropylene derivative, polyoxyethylene polystyrene phenol ether, and sodium allyl ether hydroxypropyl sulfonate, such as BASF AE-07 or AE-09. Preferably, the emulsifier is selected from a combination containing AE-07 and / or AE-09, that is, in addition to AE-07 or AE-09 emulsifiers, it also contains other types of emulsifiers in the above selection. More preferably, AE-07 and AE-09 emulsifiers account for 0.8-1.5% of the total monomer weight. The total monomer weight is the sum of the weights of hard monomers, soft monomers, and functional monomers.

[0063] In the present invention, the emulsifier is added in two parts, one part is used as the bottom liquid, and the other part is in the pre-emulsion I, and the two parts add up to 5-20 parts by mass. In fact, there is no particular restriction on the ratio of the two parts. For example, in this step, the amount of the bottom emulsifier is 1-10 parts by mass, such as 1 part by mass, 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, etc., preferably 5-8 parts by mass.

[0064] In step (1) of the present invention, the finished seed emulsion is a water-based acrylic emulsion normally sold on the market, and its particle size is 60-120nm, such as 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, etc., and the solid content is 41-43wt%. Preferably, the particle size of the finished seed emulsion is 90-120nm, for example, the particle size is 110nm, and the solid content is 42%, such as the water-based acrylic emulsion product of Wanhua Chemical. It can be understood by those skilled in the art that the amount of the finished seed emulsion added is related to the solid content. If the solid content is high, less is added accordingly, and if the solid content is low, more is added accordingly. The present invention takes a finished emulsion with a solid content of 42% as an example, but it is only an example, and other solid content solutions should also be within the scope of protection of the present invention.

[0065] In the present invention, the finished seed emulsion is added in two parts, one part is used as the bottom liquid of the kettle, and the other part is in the pre-emulsion II, and the two parts add up to 20-60 parts by mass. In fact, there is no particular restriction on the ratio of the two parts. For example, in this step, the added amount of the finished seed emulsion is 10-25 parts by mass, preferably 10-20 parts by mass.

[0066] In step (2) of the present invention, the first and second oxidants are one or more of ammonium persulfate or sodium persulfate, tert-butyl hydroperoxide, and hydrogen peroxide, preferably ammonium persulfate or sodium persulfate. In this step, the amount of the oxidant is, for example, 1-6 parts by mass, such as 1 part by mass, 2 parts by mass, 3 parts by mass, 4 parts by mass, 5 parts by mass, etc., preferably accounting for 60% to 80% of the total weight of the oxidant, preferably 3-7 parts by mass, and the remaining part is an optional post-treatment oxidant, wherein, for example, the ratio of the first oxidant and the second oxidant is not particularly limited, for example, the two parts are evenly distributed. Among them, the first oxidant and the second oxidant can be the same or different, preferably the same oxidant. According to conventional operations in the art, in order to facilitate the dropwise addition of the second oxidant to the reactor, relatively more water can be appropriately added to facilitate the dropwise addition of the second oxidant, which is a conventional operation in the art.

[0067] The pre-emulsion I in step (2) of the present invention comprises the following composition, calculated by the total mass of the pre-emulsion I:

[0068]

[0069] The preparation method of the pre-emulsion I is not particularly limited, and for example comprises the following steps: adding water, emulsifier, soft monomer, functional monomer, and hard monomer into the pre-emulsification kettle 1, and stirring at high speed for 10-30 minutes.

[0070] The emulsifier in the pre-emulsion I is any one or more of COPS-1, sodium sulfate of tridecanol polyoxyethylene ether, AE-07, AE-09, sodium salt of sulfonated diphenyl ether tetrapropylene derivative, polyoxyethylene polystyrene phenol ether, and sodium dodecyl sulfate; preferably, the emulsifier is selected from a combination containing AE-07 and / or AE-09, that is, in addition to AE-07 or AE-09 emulsifiers, it also contains other types of emulsifiers in the above selection, more preferably, AE-07, AE-09 emulsifiers account for 0.8-1.5% of the total monomer weight, and the total monomer weight is the sum of the weight of hard monomers, soft monomers and functional monomers. The amount of the emulsifier is 4-10 parts by mass, such as 4 parts by mass, 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, etc., preferably 5-10 parts by mass.

[0071] The hard monomer in the pre-emulsion I comprises one or more combinations of butyl methacrylate, acrylamide, methyl methacrylate, styrene, methacrylic acid, and acrylic acid. Preferably, the hard monomer is selected from a combination of acid monomers containing acrylic acid and / or methacrylic acid; more preferably, the acid monomer accounts for 18-21% of the total monomer weight. For example, the hard monomer is a mixture of styrene, methacrylic acid, and acrylic acid, and the amount of methacrylic acid and / or acrylic acid is preferably 18-21% of the total monomer weight. In the pre-emulsion I, the addition amount of the hard monomer is 140-160 mass parts (for example, 141 mass parts, 142 mass parts, 143 mass parts, 144 mass parts, 145 mass parts, 146 mass parts, 147 mass parts, 148 mass parts, 149 mass parts, 150 mass parts, 151 mass parts, 152 mass parts, 153 mass parts, 154 mass parts, 155 mass parts, 156 mass parts, 157 mass parts, 158 mass parts, 159 mass parts, etc.), preferably 145-155 mass parts.

[0072] The soft monomer in the pre-emulsion I comprises one or more of allyl methacrylate, isooctyl acrylate, butyl acrylate, and ethyl acrylate, and the added amount of the soft monomer is 400-550 parts by mass (e.g., 410 parts by mass, 420 parts by mass, 430 parts by mass, 440 parts by mass, 450 parts by mass, 460 parts by mass, 470 parts by mass, 480 parts by mass, 490 parts by mass, 500 parts by mass, 510 parts by mass, 520 parts by mass, 530 parts by mass, 540 parts by mass, etc.), preferably 430-500 parts by mass.

[0073] The functional monomers in the pre-emulsion I include one or more of diacetone acrylamide, hydroxyethyl methacrylate, hydroxyethyl acrylate, and β-acryloxypropionic acid, and the added amount of the functional monomers is 10-30 parts by mass (for example, 11 parts by mass, 12 parts by mass, 13 parts by mass, 14 parts by mass, 15 parts by mass, 16 parts by mass, 17 parts by mass, 18 parts by mass, 19 parts by mass, 20 parts by mass, 21 parts by mass, 22 parts by mass, 23 parts by mass, 24 parts by mass, 25 parts by mass, 26 parts by mass, 27 parts by mass, 28 parts by mass, 29 parts by mass, etc.), preferably 15-25 parts by mass.

[0074] The pre-emulsion II in step (2) of the present invention comprises the following composition, calculated by the total mass of the pre-emulsion II:

[0075] 20-35 parts by mass of finished seed emulsion, preferably 25-30 parts by mass;

[0076] 0.6-3 parts by mass, preferably 0.9-2.6 parts by mass, of pre-emulsion auxiliary agent;

[0077] Water: 5-15 parts by mass, preferably 5-10 parts by mass.

[0078] The pre-emulsion additives at least include a buffer and a chain transfer agent.

[0079] The preparation method of the pre-emulsion II is not particularly limited, and for example comprises the following steps: adding the finished seed emulsion, a buffer and a chain transfer agent into the pre-emulsification kettle 2, and stirring at a high speed for 10-30 minutes.

[0080] The finished seed emulsion in the pre-emulsion II is a water-based acrylic emulsion normally sold on the market, with a particle size of 60-120nm, such as 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, etc., and a solid content of 41-43wt%. The particle size of the preferred finished seed emulsion is 90-120nm, such as a particle size of 110nm, and a solid content of 42%, such as the water-based acrylic emulsion product of Wanhua Chemical. It can be understood by those skilled in the art that the amount of the finished seed emulsion added is related to the solid content. If the solid content is high, less is added accordingly, and if the solid content is low, more is added accordingly. The present invention takes a finished emulsion with a solid content of 42% as an example, but this is only an example, and other solid content solutions should also be within the scope of protection of the present invention. The finished seed emulsion in this step is the same as the finished seed emulsion in the bottom liquid of step (1). In this step, the added amount of the finished seed emulsion is 10-35 mass parts, for example, 10 mass parts, 12 mass parts, 14 mass parts, 15 mass parts, 16 mass parts, 18 mass parts, 20 mass parts, 21 mass parts, 22 mass parts, 23 mass parts, 24 mass parts, 25 mass parts, 26 mass parts, 27 mass parts, 28 mass parts, 29 mass parts, 30 mass parts, 31 mass parts, 32 mass parts, 33 mass parts, 34 mass parts, 35 mass parts, etc., preferably 25-30 mass parts.

[0081] In step (2) of the present invention, the buffer is one or more of sodium bicarbonate, sodium carbonate, and ammonia water, and the amount used is 0.1-1 mass parts, for example, 0.1 mass parts, 0.2 mass parts, 0.3 mass parts, 0.4 mass parts, 0.5 mass parts, 0.6 mass parts, 0.7 mass parts, 0.8 mass parts, 0.9 mass parts, 1 mass parts, etc., preferably 0.2-0.8 mass parts. The chain transfer agent is selected from any one of n-dodecyl mercaptan and mercapto butyl ester, and the added amount of the chain transfer agent is 0.5-2 mass parts, for example, 0.5 mass parts, 0.6 mass parts, 0.7 mass parts, 0.8 mass parts, 0.9 mass parts, 1 mass parts, 1.1 mass parts, 1.2 mass parts, 1.3 mass parts, 1.4 mass parts, 1.5 mass parts, 1.6 mass parts, 1.7 mass parts, 1.8 mass parts, 1.9 mass parts, 2 mass parts, etc., preferably 0.7-1.8 mass parts.

[0082] In step (3) of the present invention, the post-treatment oxidant is 1-2 parts by mass, for example, 1 part by mass, 2 parts by mass, etc., preferably 2 parts by mass. The post-treatment oxidant is preferably tert-butyl hydroperoxide, which is mainly used to remove odor from the product. This is a conventional operation well known to those skilled in the art, and can also be selectively added according to actual needs.

[0083] In step (3) of the present invention, the amount of the post-treatment reducing agent is 0.4-2 parts by mass, for example, 0.4 parts by mass, 0.5 parts by mass, 0.6 parts by mass, 0.7 parts by mass, 0.8 parts by mass, 0.9 parts by mass, 1.0 parts by mass, 1.1 parts by mass, 1.2 parts by mass, 1.3 parts by mass, 1.4 parts by mass, 1.5 parts by mass, 1.6 parts by mass, 1.7 parts by mass, 1.8 parts by mass, 1.9 parts by mass, 2 parts by mass, etc., preferably 0.5-1.5 parts by mass, and the reducing agent is one or more of sodium metabisulfite, isoascorbic acid, hydrosulfite, bleaching powder, and FF6, preferably ascorbic acid.

[0084] In step (3) of the present invention, the inorganic salt is one or more of sodium sulfate, potassium sulfate, ammonium sulfate, sodium carbonate, and sodium bicarbonate, preferably sodium sulfate, and the amount is 5-10 parts by mass, for example, 5 parts by mass, 6 parts by mass, 7 parts by mass, 8 parts by mass, 9 parts by mass, 10 parts by mass, etc., preferably 0.5-1.5 parts by mass.

[0085] In the step (3) of the present invention, the neutralizing agent is preferably ethanolamine and / or NaOH solution, and the amount used is 0.5-2 mass parts, for example, 0.5 mass parts, 0.6 mass parts, 0.7 mass parts, 0.8 mass parts, 0.9 mass parts, 1.0 mass parts, 1.1 mass parts, 1.2 mass parts, 1.3 mass parts, 1.4 mass parts, 1.5 mass parts, 1.6 mass parts, 1.7 mass parts, 1.8 mass parts, 1.9 mass parts, 2 mass parts, etc., preferably 0.7-1.5 mass parts.

[0086] In step (3) of the present invention, the defoaming agent is preferably Evonik Degussa Tego-825 and / or Tego-1488, and the amount used is 0.1-1 mass parts, for example, 0.1 mass parts, 0.2 mass parts, 0.3 mass parts, 0.4 mass parts, 0.5 mass parts, 0.6 mass parts, 0.7 mass parts, 0.8 mass parts, 0.9 mass parts, 1 mass parts, etc., preferably 0.2-0.8 mass parts.

[0087] In step (3) of the present invention, the preservative is preferably an isothiazolinone MIT preservative, and the amount used is 1-4 parts by mass, for example, 1 part by mass, 1.5 parts by mass, 2 parts by mass, 2.5 parts by mass, 3 parts by mass, 3.5 parts by mass, 4 parts by mass, etc., preferably 1.5-3.5 parts by mass.

[0088] The present invention avoids the problems of low Tg, poor anti-shear stability and inability to industrialize production of conventional adhesive products through the ingenious design of hard monomer, soft monomer and functional monomer composition, emulsifier and post-addition of inorganic salt. At the same time, the product has excellent initial adhesion, wet adhesion and sustained adhesion performance. The relevant explanation is as follows:

[0089] First of all, the pre-emulsion needs to have a medium acid content. In the monomer composition, the acid content is much higher than the acid content of conventional acrylic contact latex (1-5%), because it is necessary to ensure that the molecular chain has a high hydrophilicity. When the inorganic salt is subsequently added and the emulsifier at the bottom of the kettle migrates to the interior of the latex particles, the molecular chains can also migrate to the surface of the latex particles simultaneously, and the synergistic effect allows the latex particles to quickly reach a metastable state.

[0090] Secondly, pre-embedded AE-07 emulsifier at the bottom of the kettle has a good migration effect on acid monomers during the reaction stage, avoiding excessive water phase nucleation, ensuring polymerization stability under high acid conditions, and also providing a prerequisite for instability in the post-elimination stage.

[0091] Finally, in the post-elimination stage, with the addition of inorganic salts, the cloud point of the AE-07 emulsifier is reduced, causing the emulsifier to gradually migrate into the interior of the latex particles and the more hydrophilic molecular chains to migrate to the surface of the latex particles, which causes the hydration layer on the surface of the latex particles to become thinner and unstable, and the latex particles to transfer from a steady state to a polymerized state. During the heat preservation stage, the particle size growth state is strictly monitored through particle size detection. Preferably, when the particle size gradually increases to 400-430nm, the temperature is rapidly reduced. In order to prevent further aggregation, which leads to reduced emulsion stability and slag discharge, the cooling time is controlled within 30min. The final emulsion will be demulsified when sheared during spraying or roller coating, which greatly improves the wet adhesion performance of the acrylic contact latex and has excellent bonding performance.

[0092] In summary, the present invention, through the ingenious overall formula design, the obtained emulsion polymerization stage is stable, and at the same time the key bonding and wet adhesion properties are excellent, the relationship between the production stability and performance of the product is balanced, and the difficult problems in the industry are solved.

[0093] The present invention is further described below by more specific examples, but does not constitute any limitation.

[0094] In the following examples, parts are by weight unless otherwise specified.

[0095] Table 1 Raw materials used to prepare acrylic contact latex

[0096]

[0097]

[0098] Example 1: Emulsion 1-1

[0099] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 3.3 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 3.3 parts of polyoxyethylene polystyrene phenol ether 710, 133 parts of isooctyl acrylate EHA, 8.5 parts of hydroxyethyl acrylate, 9.5 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 125 parts of ethyl acrylate EA, 75 parts of methacrylic acid MAA, 50 parts of acrylic acid AA, 25 parts of styrene ST, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0100] Preparation of pre-emulsion II: 26.1 parts of finished seed emulsion, 0.4 parts of sodium bicarbonate, 1.3 parts of n-dodecyl mercaptan N-DM, and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0101] Weigh 0.9 parts of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 2.0 parts of ammonium persulfate APS and dissolve it in 30 parts of deionized water DIW to prepare a second oxidant solution.

[0102] Add 110 parts of deionized water to the reactor, heat to 70°C, add 3.3 parts of allyl ether hydroxypropyl sulfonate COPS-1, 7 parts of ethoxylated C12-14 alcohol AE-07 and 13.3 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and add the pre-emulsion I solution and the second oxidant solution after 3 minutes, and control the reaction temperature at 70°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 180 minutes. After keeping warm for 45 minutes, the temperature of the contents in the reactor was lowered to 60°C, and 2 parts of tert-butyl hydroperoxide (TBHP) dissolved in 10 parts of deionized water (DIW) and 0.8 parts of isoascorbic acid (IAA) dissolved in 10 parts of deionized water (DIW) were added dropwise for 40 minutes. Then, 6 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 60°C for 30 minutes. Then, keeping warm and monitoring the particle size were started. When keeping warm for 10-20 minutes, the particle size increased to 400-430 nm. The temperature was rapidly lowered to 50°C for 20 minutes. Then, 2 parts of MEA were added for neutralization, 0.4 parts of defoaming agent Tego-825 and 1.9 parts of preservative Kordek MLX were added to obtain emulsion 1-1.

[0103] Example 2: Emulsion 1-2

[0104] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 1 part of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 1 part of polyoxyethylene polystyrene phenol ether 710, 94 parts of isooctyl acrylate EHA, 7 parts of hydroxyethyl acrylate, 8 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 131 parts of ethyl acrylate EA, 16 parts of methacrylic acid MAA, 4 parts of acrylic acid AA, 140 parts of styrene ST, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0105] Preparation of pre-emulsion II: 30 parts of finished seed emulsion, 1.0 part of n-dodecyl mercaptan N-DM, 1.0 part of sodium bicarbonate and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0106] Weigh 1.9 parts of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 1.5 parts of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0107] Add 110 parts of deionized water to the reactor, heat to 80°C, add 6.9 parts of allyl ether hydroxypropyl sulfonate COPS-1, 4.5 parts of ethoxylated C12-14 alcohol AE-07, and 30 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 5 minutes, add the pre-emulsion I solution and the second oxidant solution, and control the reaction temperature at 80°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 360 minutes. After keeping warm for 45 minutes, the temperature of the contents in the reactor was lowered to 70°C, and 2 parts of tert-butyl hydroperoxide (TBHP) dissolved in 10 parts of deionized water (DIW) and 1.5 parts of isoascorbic acid (IAA) dissolved in 10 parts of deionized water (DIW) were added dropwise for 40 minutes. Then, 5 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 70°C for 30 minutes. Then, keeping warm for 10-20 minutes, the temperature was rapidly lowered to 50°C for 25 minutes. Then, 3.1 parts of MEA were added for neutralization, 0.4 parts of defoaming agent Tego-825 and 1.9 parts of preservative Kordek MLX were added to obtain emulsion 1-2.

[0108] Example 3: Emulsion 1-3

[0109] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 1.5 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 1.5 parts of polyoxyethylene polystyrene phenol ether 710, 133 parts of isooctyl acrylate EHA, 8.5 parts of hydroxyethyl acrylate, 1.5 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 205 parts of ethyl acrylate EA, 75 parts of methacrylic acid MAA, 80 parts of acrylic acid AA, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0110] Preparation of pre-emulsion II: 20 parts of finished seed emulsion, 1.3 parts of n-dodecyl mercaptan N-DM, 1.3 parts of sodium bicarbonate NaHCO3, and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0111] Weigh 1 part of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 1 part of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0112] Add 110 parts of deionized water to the reactor, heat to 90°C, add 1 part of allyl ether hydroxypropyl sulfonate COPS-1, 7 parts of ethoxylated C12-14 alcohol AE-07, and 10 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion I solution and the second oxidant solution, and control the reaction temperature at 90°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 180 minutes. After keeping warm for 45 minutes, the temperature of the contents in the reactor was lowered to 65°C, and 2 parts of tert-butyl hydroperoxide (TBHP) dissolved in 10 parts of deionized water (DIW) and 1 part of isoascorbic acid (IAA) dissolved in 10 parts of deionized water (DIW) were added dropwise for 40 minutes. Then, 7 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 65°C for 30 minutes. Then, keeping warm was started for 10-20 minutes. The particle size increased to 520 nm. The temperature was rapidly lowered to 50°C for 18 minutes. Then, 4 parts of MEA were added for neutralization, 0.4 parts of defoaming agent Tego-825 and 1.4 parts of preservative Kordek MLX were added to obtain emulsion 1-3.

[0113] Example 4: Emulsion 1-4

[0114] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 3.3 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 3.7 parts of polyoxyethylene polystyrene phenol ether 710, 133 parts of isooctyl acrylate EHA, 12 parts of hydroxyethyl acrylate, 12 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 195 parts of ethyl acrylate EA, 75 parts of methacrylic acid MAA, 45 parts of acrylic acid AA, 20 parts of styrene ST, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0115] Preparation of pre-emulsion II: 15 parts of finished seed emulsion, 1 part of n-dodecyl mercaptan N-DM, 1.6 parts of sodium bicarbonate NaHCO3, and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0116] Weigh 1 part of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 2.0 parts of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0117] Add 110 parts of deionized water to the reactor, heat to 85°C, add 2 parts of allyl ether hydroxypropyl sulfonate COPS-1, 9 parts of ethoxylated C12-14 alcohol AE-07, and 6 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion I solution and the second oxidant solution, and control the reaction temperature at 85°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 180 minutes. After keeping the temperature for 45 minutes, the contents in the reactor were cooled to 75°C, and 2 parts of tert-butyl hydroperoxide TBHP dissolved in 10 parts of deionized water DIW and 0.6 parts of isoascorbic acid IAA dissolved in 10 parts of deionized water DIW were added dropwise for 40 minutes, and then 8 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 75°C for 30 minutes, and then the temperature was kept and the particle size was monitored, and the temperature was kept for 10-20 minutes, and the temperature was slowly lowered to 50°C for 60 minutes, and then 2.1 parts of MEA were added for neutralization, 0.4 parts of defoamer Tego-825 and 1.5 parts of preservative Kordek MLX were added. Emulsion 1-4 was obtained.

[0118] Example 5: Emulsion 1-5

[0119] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 1 part of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 1 part of polyoxyethylene polystyrene phenol ether 710, 140 parts of isooctyl acrylate EHA, 7.5 parts of hydroxyethyl acrylate, 7.5 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 146 parts of ethyl acrylate EA, 75 parts of methacrylic acid MAA, 50 parts of acrylic acid AA, 25 parts of styrene ST, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0120] Preparation of pre-emulsion II: 18 parts of finished seed emulsion, 0.8 parts of n-dodecyl mercaptan N-DM, 1.5 parts of sodium bicarbonate NaHCO3, and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0121] Weigh 2 parts of ammonium persulfate APS and dissolve them in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 2.0 parts of ammonium persulfate APS and dissolve them in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0122] Add 110 parts of deionized water to the reactor, heat to 80°C, add 1 part of allyl ether hydroxypropyl sulfonate COPS-1, 12 parts of ethoxylated C12-14 alcohol AE-07, and 18 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion I solution and the second oxidant solution, and control the reaction temperature at 80°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 180 minutes. After keeping the temperature for 45 minutes, the temperature in the reactor was lowered to 65°C, and 2 parts of tert-butyl hydroperoxide TBHP dissolved in 10 parts of deionized water DIW and 0.8 parts of isoascorbic acid IAA dissolved in 10 parts of deionized water DIW were added dropwise for 40 minutes, and then 7.5 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 65°C for 30 minutes, and then the temperature was kept and the particle size was monitored for 10-20 minutes, and then the temperature was quickly lowered to 50°C for 17 minutes, and then 2 parts of MEA were added for neutralization, 0.4 parts of defoamer Tego-825 and 1.6 parts of preservative Kordek MLX were added. Emulsion 1-5 was obtained.

[0123] Example 6: Emulsion 1-6

[0124] Preparation of pre-emulsion I: 95.7 parts of deionized water DIW, 1.5 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 1.5 parts of polyoxyethylene polystyrene phenol ether 710, 133 parts of isooctyl acrylate EHA, 15 parts of hydroxyethyl acrylate, 15 parts of β-acryloxypropionic acid, 175 parts of butyl acrylate BA, 125 parts of ethyl acrylate EA, 75 parts of methacrylic acid MAA, 45 parts of acrylic acid AA, 30 parts of styrene ST, prepared in pre-emulsification kettle 1 and stirred thoroughly.

[0125] Preparation of pre-emulsion II: 10 parts of finished seed emulsion, 0.6 parts of n-dodecyl mercaptan N-DM, 0.6 parts of sodium bicarbonate NaHCO3, and 7 parts of deionized water are prepared in pre-emulsification kettle 2 and stirred thoroughly.

[0126] Weigh 1.7 parts of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 1.7 parts of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0127] Add 110 parts of deionized water to the reactor, heat to 65°C, add 1 part of allyl ether hydroxypropyl sulfonate COPS-1, 3 parts of ethoxylated C12-14 alcohol AE-07, and 20 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion I solution and the second oxidant solution, and control the reaction temperature at 65°C. At the same time, add the pre-emulsion II to the pre-emulsion I until all the additions are completed, and the addition time is 180 minutes. After keeping the temperature for 45 minutes, the temperature in the reactor was lowered to 55°C, and 2 parts of tert-butyl hydroperoxide TBHP dissolved in 10 parts of deionized water DIW and 1.4 parts of isoascorbic acid IAA dissolved in 10 parts of deionized water DIW were added dropwise for 40 minutes, and then 6.3 parts of sodium sulfate dissolved in 50 parts of water were added dropwise at 55°C for 30 minutes, and then the temperature was kept and the particle size was monitored, and the temperature was kept for 10-20 minutes, and the temperature was quickly lowered to 50°C for 28 minutes, and then 1 part of MEA was added for neutralization, 0.4 parts of defoaming agent Tego-825 and 1 part of preservative Kordek MLX were added. Emulsion 1-6 was obtained.

[0128] Comparative Example 1: Emulsion 2-1

[0129] Preparation of pre-emulsion: 126 parts of deionized water DIW, 3.3 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 3.3 parts of polyoxyethylene polystyrene phenol ether 710, 275.3 parts of isooctyl acrylate EHA, 8.5 parts of hydroxyethyl acrylate, 9.5 parts of β-acryloxypropionic acid, 294.3 parts of butyl acrylate, 49.8 parts of methyl methacrylate MMA, 15 parts of methacrylic acid MAA, and 1.3 parts of n-dodecyl mercaptan N-DM are prepared in a pre-emulsification kettle and stirred thoroughly.

[0130] Weigh 0.9 parts of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 2.0 parts of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0131] Add 125.6 parts of deionized water to the reactor, heat to 80-85°C, add 4.3 parts of allyl ether hydroxypropyl sulfonate COPS-1, 0.4 parts of sodium bicarbonate NaHCO3 and 39.4 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion solution and the second oxidant solution, and control the reaction temperature at 80-85°C. Until all the additions are completed, the addition time is 180 minutes. After keeping warm for 45 minutes, reduce the temperature of the reactor to 65-75°C, and add 1.4 parts of tert-butyl hydroperoxide TBHP dissolved in 10 parts of deionized water DIW and 0.8 parts of isoascorbic acid IAA dissolved in 10 parts of deionized water DIW, and the addition time is 40 minutes. The temperature was lowered to below 50°C, and 1.1 parts of MEA were added for neutralization, 0.4 parts of defoamer Tego-825 and 1.9 parts of preservative Kordek MLX were added to obtain emulsion 2-1.

[0132] Comparative Example 2: Emulsion 2-2

[0133] Preparation of pre-emulsion: 150 parts of deionized water DIW, 3.3 parts of sulfonated diphenyl ether tetrapropylene derivative sodium salt 2A1, 3.3 parts of polyoxyethylene polystyrene phenol ether 710, 200.3 parts of isooctyl acrylate EHA, 8.5 parts of hydroxyethyl acrylate, 9.5 parts of β-acryloxypropionic acid, 244.3 parts of butyl acrylate, 99.8 parts of methyl methacrylate MMA, 75 parts of styrene ST, 15 parts of methacrylate MAA, 1.3 parts of n-dodecyl mercaptan N-DM are prepared in a pre-emulsification kettle and stirred thoroughly.

[0134] Weigh 0.9 parts of ammonium persulfate APS and dissolve it in 10 parts of deionized water DIW to prepare a first oxidant solution; weigh 2.0 parts of ammonium persulfate APS and dissolve it in 38 parts of deionized water DIW to prepare a second oxidant solution.

[0135] Add 125.6 parts of deionized water to the reactor, heat to 80-85°C, add 4.3 parts of allyl ether hydroxypropyl sulfonate COPS-1, 0.4 parts of sodium bicarbonate NaHCO3 and 39.4 parts of finished seed emulsion. Add the first oxidant solution to the reactor, and after 3 minutes, add the pre-emulsion solution and the second oxidant solution, and control the reaction temperature at 80-85°C. Until all the additions are completed, the addition time is 180 minutes. After keeping warm for 45 minutes, reduce the temperature of the reactor to 65-75°C, and add 1.4 parts of tert-butyl hydroperoxide TBHP dissolved in 10 parts of deionized water DIW and 0.8 parts of isoascorbic acid IAA dissolved in 10 parts of deionized water DIW, and the addition time is 40 minutes. The temperature was lowered to below 50°C, and 1.1 parts of MEA were added for neutralization, 0.4 parts of defoamer Tego-825 and 1.9 parts of preservative Kordek MLX were added to obtain emulsion 2-1.

[0136] The contact latex prepared in the above examples and comparative examples was tested according to the following standards:

[0137] Initial adhesion test standard: select two sponges of the same size, apply the prepared emulsion on the cross-section of each sponge, and when the two sponges are put together, feel the strength of the force used with your hands. It is divided into three levels: light - A+++, medium - A++, heavy - A+. The lighter the force, the better the initial adhesion of the emulsion.

[0138] Wet adhesion test standard: select two sponges of the same size, apply the prepared emulsion on the cross-section of both sponges, and then tear them apart immediately after they are attached to each other. Observe the glue remaining on the attached surfaces of the two sponges, which is divided into three levels: the material is broken when torn apart - A+++, a large amount of glue is left on both sides when torn apart - A++, and glue is left on one side when torn apart - A+. The material is broken when torn apart, which means that the wet adhesion performance of the emulsion is the best.

[0139] Cohesion test standard: select a sponge, apply the prepared emulsion on the cross section, then fold it in half and stick it together, dry it at 25°C for 25 hours, and test the debonding distance after drying in mm. The smaller the distance, the better the cohesion.

[0140] Particle size: Malvern ZS90 particle size analyzer, polystyrene latex model, water as the dispersion medium General purpose analysis method.

[0141] Process viscosity: measured using Brookfield LV63#30r and 64#60r.

[0142] Slag content: Use 325 mesh filter and determine using WHPU / T011-685-2015 analysis method.

[0143] Table 2 Experimental conditions of the embodiments and comparative examples

[0144] Experiment No. condition Acid ratio Cooling time after adding inorganic salt AE07 content Example 1 Preferred samples 20.8 20 1.2 Example 2 Acid reduction 3.5 25 0.8 Example 3 Increased acidity 22.9 18 1 Example 4 Extended cooling time 18 60 1.5 Example 5 AE07 volume increased 20 17 1.9 Example 6 AE07 quantity reduction 19.6 28 0.5 Comparative Example 1 Conventional adhesive emulsion low Tg 2.3 63 0 Comparative Example 2 Conventional adhesive emulsion high Tg 2.3 70 0

[0145] Table 3 Emulsion performance test comparison

[0146]

[0147]

[0148] As can be seen from Table 3, the present invention adopts a special production process with an ingenious overall formula design. The prepared emulsion Example 1-1 is stable in the polymerization stage compared with the comparative examples 2-1 and 2-2, and the slag content can be controlled within 100ppm, meeting the requirements of industrialization. At the same time, the key bonding and wet adhesion properties are excellent, both reaching A+++ or above, and the cohesive performance is also outstanding, which balances the relationship between the production stability and performance of the product. The comprehensive score is 10 points, which completely solves the difficult problems in this industry.

[0149] By examining the three key factors of acid amount, cooling time after adding inorganic salt, and AE07 emulsifier content in Examples 1-6, it can be found that the acid amount and AE07 emulsifier affect the slag content and key properties of the emulsion, and the cooling time after adding inorganic salt mainly affects the slag content of the product. By optimizing the combination of the three key factors, the emulsion production stability can be better and the performance can be more excellent.

[0150] Finally, it should be noted that the above contact latex embodiments are only used to describe the preferred embodiments of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that various modifications and improvements made by modifying or equivalently replacing the technical solution of the present invention should all fall within the scope of protection determined by the claims of the present invention.

Claims

1. A water-based acrylic contact latex, It is characterized in that Contains the following components by weight: Preferably, the aqueous acrylic contact latex has a solid content of 65wt%-67wt% and a particle size of 300-500nm.

2. The aqueous acrylic contact latex according to claim 1, It is characterized in that The hard monomer is selected from any one or more combinations of butyl methacrylate, acrylamide, methyl methacrylate, styrene, acrylic acid, and methacrylic acid. Preferably, the hard monomer is selected from a combination of acid monomers containing acrylic acid and / or methacrylic acid; more preferably, the acid monomers account for 18-21% of the total monomer weight.

3. The aqueous acrylic contact latex according to claim 1, It is characterized in that The soft monomer is selected from any one or more of allyl methacrylate, isooctyl acrylate, butyl acrylate and ethyl acrylate.

4. The aqueous acrylic contact latex according to claim 1, It is characterized in that The functional monomer is selected from one or two of diacetone acrylamide, hydroxyethyl methacrylate, hydroxyethyl acrylate, and β-acryloxypropionic acid.

5. The aqueous acrylic contact latex according to claim 1, It is characterized in that The finished seed emulsion is a commercially available aqueous acrylic emulsion with a particle size of 60-120 nm and a solid content of 42-43%, preferably a particle size of 90-120 nm.

6. The aqueous acrylic contact latex according to claim 1, It is characterized in that The emulsifier is any one or more combinations of COPS-1, sodium tridecyl alcohol polyoxyethylene ether sulfate, AE-07, AE-09, sodium salt of sulfonated diphenyl ether tetrapropylene derivative, polyoxyethylene polystyrene phenol ether, sodium allyl ether hydroxypropyl sulfonate, and sodium dodecyl sulfate; preferably, the emulsifier is selected from a combination containing AE-07 and / or AE-09; more preferably, AE-07 and AE-09 emulsifiers account for 0.8-1.5% of the total monomer weight.

7. The aqueous acrylic contact latex according to claim 1, It is characterized in that The pre-emulsion auxiliary agent includes at least any one of a chain transfer agent and a buffer; preferably, the chain transfer agent is any one of n-dodecyl mercaptan and butyl mercapto, and the buffer is any one of sodium bicarbonate, sodium carbonate, and ammonia water.

8. The aqueous acrylic contact latex according to any one of claims 1 to 7, It is characterized in that The oxidant is one or more of ammonium persulfate, sodium persulfate, tert-butyl hydroperoxide, and hydrogen peroxide; Preferably, the reducing agent is one or more of sodium pyrosulfite, isoascorbic acid, hydrosulfite, bleaching powder, and FF6; Preferably, the inorganic salt is one or more of sodium sulfate, potassium sulfate, ammonium sulfate, sodium carbonate, and sodium bicarbonate; Preferably, the post-added auxiliary agent includes at least any one of a neutralizer, a defoamer, and a preservative commonly used in emulsion polymerization.

9. A method for preparing the aqueous acrylic contact latex according to any one of claims 1 to 8, It is characterized in that The steps include: (1) Add water to the reaction kettle, heat it to 65-95° C., and add emulsifier and finished seed emulsion to the bottom of the kettle; (2) adding the first oxidant to the reactor at 65-95° C., preferably 1-15 minutes later, adding the pre-emulsion I and the second oxidant to the reactor, and simultaneously adding the pre-emulsion II to the pre-emulsion I until all the pre-emulsions are added, preferably, the total addition time is 180-360 minutes; (3) Keep warm for 30-60 min, cool to 55-75° C., and simultaneously add optional post-treatment oxidizing agent and reducing agent dropwise, preferably for 30-60 min, and then continue to add inorganic salt solution dropwise, preferably for 20-40 min. After the addition is completed, start keeping warm. During the keeping warm process, test the product particle size. When the particle size reaches 400-430 nm, then quickly cool to below 50° C., the cooling time is required to be ≤30 min, and then add the post-addition auxiliary agent, adjust the pH to 3.0-6.5, and filter the material.

10. The preparation method according to claim 9, It is characterized in that The pre-emulsion I comprises the following composition, calculated by the total mass of the pre-emulsion I: Preferably, the pre-emulsion II comprises the following composition, calculated by the total mass of the pre-emulsion II: 10-35 parts by mass of finished seed emulsion, preferably 25-30 parts by mass; 0.6-3 parts by mass, preferably 0.9-2.6 parts by mass, of pre-emulsion auxiliary agent; Water: 5-15 parts by mass, preferably 5-10 parts by mass.

11. Use of the aqueous acrylic contact rubber latex according to any one of claims 1 to 8 in contact rubber.

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