High temperature odorless thermal sublimation transfer paper acrylate emulsion and preparation method thereof

Abstract

The present application relates to the technical field of acrylate emulsion, and discloses a high-temperature odorless thermal sublimation paper acrylate emulsion and a preparation method thereof.The emulsion comprises water, alkyl acrylate, styrene, methyl methacrylate, unsaturated hydroxyl functional monomer, crosslinking monomer, reactive emulsifier, initiator and pH regulator. Suitable soft monomer and hard monomer are adopted to make the thermal sublimation paper coating obtain excellent smoothness; the hydroxyl functional group is added to improve the riveting with the paper and the ink absorption is carried out by capillary action; the functional monomer is adopted to improve the temperature resistance of the polymer; the reactive emulsifier is adopted to graft the emulsifier to the polymer, avoid free, make the emulsion not easy to volatilize under high temperature conditions, not produce odor and VOC. A two-step method is adopted to solve free VOC and small molecules, the initiation polymerization step is added in the heat preservation stage, the temperature is improved and the initiator is added dropwise, and the effective polymerization of free monomers in the liquid phase is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of acrylate emulsion, in particular to a high-temperature odorless sublimation transfer paper acrylate emulsion and a preparation method thereof. BACKGROUND

[0002] The sublimation transfer printing technology refers to a process of pre-printing ink with sublimation characteristics on a thermal transfer paper by using digital technology, and then giving the paper a high temperature (about 200℃) and pressure by a thermal transfer equipment, so that the sublimation ink is sublimated from solid to gas under high temperature and pressure, and penetrates into the printing material, thereby transferring the text or pattern on the paper to the printing material.

[0003] Due to the characteristics of low capital investment, small environmental pollution, low resource consumption and outstanding printing effect, the sublimation transfer printing technology has attracted the attention of investors in China, and therefore, its development speed in China is relatively fast, maintaining a growth trend of 20-30% in recent years. The main reason for maintaining a good growth trend is the practicality of the technology, and the sublimation transfer printing technology is related to multiple industries in China and has achieved good economic and social benefits.

[0004] The main function of latex in the coating of sublimation transfer paper is adhesion. Since the latex has excellent film-forming properties, it can effectively improve the smoothness and gloss of the sublimation transfer paper, and ensure the clarity and delicacy of the printed image, so it is widely used in sublimation transfer paper. Generally, conventional styrene-butadiene latex and acrylate emulsion are used as adhesives on the market, but the above raw materials are prone to volatile VOC harmful substances at high temperatures, which is contrary to green and environmentally friendly production, and affects human health and economic benefits. In addition, the products transferred by styrene-butadiene latex have a low density value, resulting in a large amount of ink remaining on the paper, poor transfer effect, and poor water resistance and poor water washing fastness of conventional acrylate emulsion, which greatly limits the development of sublimation transfer paper in the market.

[0005] Therefore, how to develop a high-temperature odorless sublimation transfer paper acrylate emulsion without affecting the normal performance of sublimation transfer is a big problem for sublimation transfer paper acrylate emulsion.

[0006] It can be seen that the prior art still needs to be improved and improved. SUMMARY

[0007] In view of the shortcomings of the prior art, the purpose of the present application is to provide a high-temperature odorless sublimation transfer paper acrylate emulsion and a preparation method thereof, so that the emulsion is odorless at high temperature and has good sublimation transfer performance.

[0008] In order to achieve the above object, the present application adopts the following technical solutions:

[0009] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0010] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0011] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0012] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0013] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0014] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0015] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0016] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0017] The high-temperature odorless thermal sublimation transfer paper acrylate emulsion comprises the following components in parts by weight: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator.

[0018] Preparation of the base liquid A: 47-51 parts of deionized water and 0.7-1.3 parts of a reactive emulsifier were added to a polymerization kettle, the temperature was raised to 70-80°C, and stirring was carried out for 1-2 hours;

[0019] Preparation of the pre-emulsion B: 36-43 parts of an alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of an unsaturated hydroxyl functional monomer, 1-3 parts of a crosslinking monomer, 0.3-1.2 parts of a reactive emulsifier, and 25-29 parts of deionized water were added to a pre-emulsion tank at normal temperature and pressure, and stirring was carried out to obtain a uniform pre-emulsion B, which was ready for use;

[0020] Preparation of the initiator solution C: 0.6-1.1 parts of an initiator and 8-12 parts of deionized water were added to an initiator tank at normal temperature and pressure to obtain a uniform initiator solution C, which was ready for use;

[0021] Preparation of the initiator solution D: 0.4-1.4 parts of an initiator and 12-18 parts of deionized water were added to an initiator tank at normal temperature and pressure to obtain a uniform initiator solution D, which was ready for use;

[0022] When the temperature in the polymerization kettle reached 70-80°C, 4-8% of the pre-emulsion B based on the weight of the pre-emulsion B and 12-18% of the initiator solution C based on the weight of the initiator solution C were added to the kettle, and the reaction was carried out for 10-30 minutes, after which the remaining pre-emulsion B and the remaining initiator solution C were added to the polymerization kettle simultaneously, and the titration time was controlled to be 220-300 minutes;

[0023] The temperature in the polymerization kettle was raised to 80-90°C, and the kettle was kept at this temperature;

[0024] The initiator solution D was added to the polymerization kettle, and the temperature in the kettle was controlled to be 80-90°C, and the addition time was controlled to be 80-120 minutes;

[0025] After the addition of the initiator solution D was completed, the temperature in the polymerization kettle was controlled to be 80-90°C, and the kettle was kept at this temperature for 1-2 hours;

[0026] The temperature in the polymerization kettle was lowered to 40-50°C, 0.2-0.5 parts of a pH adjuster were added to the kettle, and stirring was carried out for 0.5-1 hour, after which the product was filtered to obtain the high-temperature odor-free thermal sublimation transfer paper acrylic emulsion.

[0027] The preparation method of the high-temperature odor-free thermal sublimation transfer paper acrylic emulsion further comprises the step of subjecting the emulsion to negative pressure extraction at a pressure of -0.07 to -0.09 MPa for 3-5 hours after the addition of the pH adjuster and the completion of stirring.

[0028] Advantages:

[0029] The application provides a preparation method of high-temperature odor-free thermal sublimation transfer paper acrylate emulsion, and has the following advantages.

[0030] 1. The soft monomer and the hard monomer are compounded, the minimum film forming temperature of the emulsion is designed to be 20-25 DEG C, the film forming performance of the latex is good, the thermal sublimation paper coating has excellent smoothness, and the competitive polymerization rate of different monomers can make the polymer better graft polymerization into a high molecular chain, and the free monomers in the reaction system are reduced. The selected monomers do not produce additional by-products in the polymerization process, avoid the formation of odor molecules by by-products, and control the odor and VOC of the emulsion from the selection of raw materials.

[0031] 2. The unsaturated hydroxyl functional monomer provides a hydroxyl functional group, the hydrogen bond provided is bonded with the thermal sublimation paper fiber, firmly combined, the adhesion of the coating is improved, and the thermal sublimation paper coating and the color filler form micropores, the capillary action of the micropores is utilized, the capillary is convenient for the absorption of thermal sublimation ink, the physical ink absorption effect makes the coating have excellent ink absorption performance, the ink is fixed and riveted, and the ink does not spread. At the same time, the suitable hydrogen bond energy is good for the transfer of the ink at a high temperature of 200 DEG C, and the printed image does not have the phenomenon of ink stacking, which is beneficial to improve the transfer quality of the thermal sublimation paper.

[0032] 3. The functional monomer with high crosslinking degree can combine linear high molecules into a network structure, the structure of the emulsion is more firm, the temperature resistance of the polymer is greatly improved, the coating is not easy to volatilize gas at high temperature, and the phenomenon of chain decomposition occurs. In addition, the crosslinking monomer assists the adhesion of the thermal sublimation paper coating, improves the firmness of the coating and the tensile strength of the paper, and prevents the paper from warping and deforming.

[0033] 4. The reaction type emulsifier can form micellar emulsified monomers in the early stage of the reaction, control the stability of the latex and the particle size of the latex, make the emulsion fully wrap the thermal sublimation coating powder. In addition, the emulsifier contains a reactive double bond which can participate in the reaction, so that the reaction type emulsifier can be grafted into the polymer, and the free state of the conventional auxiliary molecules is eliminated, and the auxiliary molecules do not volatilize and produce odor and VOC at high temperature.

[0034] 5. The two-step method is used in the preparation method to solve the free VOC and small molecules, the polymerization step is added in the heat preservation stage, the temperature is increased and the initiator is added dropwise, the half-life of the initiator is compensated, the free monomers in the liquid phase are effectively polymerized. In addition, the high-temperature negative pressure extraction process is added, the residual small molecules and VOC of the polymerized latex are removed at the fixed point, the odor of the emulsion is purified, and the odor of the emulsion is prevented from volatilizing at high temperature.

[0035] 6. The preparation process employs a seed pre-emulsification semi-continuous dropwise addition technique, allowing for a more complete and stable reaction in the polymerization system, resulting in a lower gelation rate. A water bath is used as the heating medium, providing a convenient heating source and enabling cyclical production. Detailed Implementation

[0036] This invention provides an acrylic emulsion for high-temperature deodorizing thermal sublimation transfer paper and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided for further detailed explanation. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of protection of this invention.

[0037] This invention provides an acrylic emulsion for high-temperature deodorizing thermal sublimation transfer paper, comprising the following components by weight: 92-110 parts deionized water, 36-43 parts alkyl acrylate, 28-31 parts styrene, 12-17 parts methyl methacrylate, 2-5 parts unsaturated hydroxyl functional monomers, 1-3 parts crosslinking monomers, 1.0-2.5 parts reactive emulsifiers, 1-2.5 parts initiators, and 0.2-0.5 parts pH adjusters.

[0038] In the aforementioned emulsion, alkyl acrylate, styrene, and methyl methacrylate serve as the main structural monomers. Alkyl acrylate acts as a soft monomer, while styrene and methyl methacrylate act as hard monomers. Through the combination of soft and hard monomers, the emulsion's minimum film-forming temperature (MFFT) is designed to be between 20 and 25°C, resulting in excellent film-forming properties and superior smoothness for the thermal sublimation paper coating. Simultaneously, the appropriate ratio of different monomer species' polymerization competition allows for better graft polymerization into polymer chains, reducing the free state of monomers in the reaction system. The selected monomers do not generate additional byproducts during polymerization, avoiding the formation of odorous molecules from byproduct products, thus controlling the odor and VOCs of the emulsion through raw material selection.

[0039] In some embodiments, the alkyl acrylate includes one or more of butyl acrylate, isooctyl acrylate, lauryl acrylate, and octadecyl acrylate.

[0040] In some embodiments, the unsaturated hydroxyl functional monomer includes one or more of hydroxyethyl acrylate and hydroxyethyl methacrylate. The unsaturated hydroxyl functional monomer provides a hydroxyl functional group, which forms a hydrogen bond with the fibers of the thermal sublimation paper, firmly binds the thermal sublimation paper, improves the adhesion of the coating, and helps form micropores between the coating and the pigments and fillers of the thermal sublimation paper, so that the micropores can facilitate capillary action of the thermal sublimation ink. The physical ink absorption of the micropores can improve the ink absorption performance of the coating, and can fix the ink in place, so that the ink does not spread. At the same time, the appropriate hydrogen bond energy can improve the transferability of the ink at high temperatures of 200°C, and can prevent ink from piling up on the printed image, thereby improving the transfer quality of the thermal sublimation paper.

[0041] In some embodiments, the crosslinking monomer includes one or more of glycidyl methacrylate, dicyclopentenyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. The high crosslinking functional monomer can combine linear polymers into a network structure, and the molecular structure of the emulsion is more stable, so that the heat resistance of the polymer is greatly improved, and the coating is less likely to volatilize gas at high temperatures. In addition, the crosslinking monomer can improve the adhesion of the thermal sublimation paper coating, improve the firmness of the coating, and improve the tensile strength of the paper, thereby preventing the paper from warping and deforming.

[0042] In some embodiments, the reactive emulsifier is a product of a reactive anionic emulsifier and a reactive nonionic emulsifier in a weight ratio of 1:(1-2.5); the reactive anionic emulsifier includes one or more of SR-10, SR-20, and SR-30 of ADEKA; and the reactive nonionic emulsifier includes one or more of ER-10, ER-20, and ER-30 of ADEKA. The reactive emulsifier can form micellar emulsified monomers in the early stage of the reaction, control the stability of the latex, and control the particle size of the latex, so that the emulsion can fully wrap the pigments and fillers of the thermal sublimation coating. In addition, the reactive double bond of the emulsifier can participate in the reaction, so that the reactive emulsifier can be grafted to the polymer, and the free state of the conventional auxiliary molecules is eliminated, so that the auxiliary molecules do not volatilize and do not produce odor and VOC at high temperatures.

[0043] In some embodiments, the initiator includes one or more of sodium persulfate and potassium persulfate. The persulfate salt is an oxidizing agent, and the emulsion is prepared by a thermal decomposition initiator method. In order to compensate for the half-life of the initiator, a second initiator is added in the holding stage to promote the reaction of the residual monomers, so that the reaction is easy to polymerize and complete, and the residual monomers in the emulsion are removed, thereby reducing odor.

[0044] In one embodiment, the pH adjusting agent includes one or more of sodium hydroxide, sodium bicarbonate, and sodium carbonate. The addition of the pH adjusting agent to the emulsion facilitates stability at slightly alkaline conditions in the system. The pH adjusting agent does not volatilize and has no odor relative to ammonia.

[0045] The present application also provides a method for preparing a high-temperature odorless thermal sublimation transfer paper acrylate emulsion, comprising the following steps:

[0046] (1) Preparation of base liquid A: Add 47-51 parts of deionized water and 0.7-1.3 parts of reactive emulsifier to a polymerization kettle equipped with a stirrer, condenser, and constant-flow pump feeding device, heat to a kettle temperature of 70-80°C, and stir for 1-2 hours.

[0047] (2) Preparation of pre-emulsion B: At normal temperature and pressure, add 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 0.3-1.2 parts of reactive emulsifier, and 25-29 parts of deionized water to a pre-emulsion tank equipped with a monomer metering tank and a stirrer, stir to mix into a uniform pre-emulsion B, and stir for 10-50 minutes for standby use.

[0048] (3) Preparation of initiator solution C: At normal temperature and pressure, add 0.6-1.1 parts of initiator and 8-12 parts of deionized water to an initiator tank equipped with a stirrer and constant-flow dropping device, and prepare a uniform initiator solution C for standby use.

[0049] (4) Preparation of initiator solution D: At normal temperature and pressure, add 0.4-1.4 parts of initiator and 12-18 parts of deionized water to the initiator tank, and prepare a uniform initiator solution D for standby use.

[0050] (5) When the temperature in the polymerization kettle reaches 70-80°C, add 4-8% of the pre-emulsion B based on the weight of the pre-emulsion B and 12-18% of the initiator solution C based on the weight of the initiator solution C to the kettle, and after reacting for 10-30 minutes, simultaneously add the remaining pre-emulsion B and the remaining initiator solution C to the polymerization kettle through the constant-flow pump feeding device and the constant-flow dropping metering device, and control the titration time to be 220-300 minutes.

[0051] (6) Raise the temperature in the polymerization kettle to 80-90°C, and maintain the temperature for 0.5-1 hour.

[0052] (7) Add the initiator solution D to the polymerization kettle through the constant-flow pump feeding device, and control the temperature in the polymerization kettle to be 80-90°C, and control the dropping time to be 80-120 minutes.

[0053] (8) After the dropping of the initiator solution D is completed, the temperature in the polymerization kettle is controlled at 80-90℃, and the temperature is kept for 1-2 hours.

[0054] (9) The temperature in the polymerization kettle is reduced to 40-50℃, 0.2-0.5 parts of a pH regulator is added into the polymerization kettle, and stirring is carried out for 0.5-1 hour; then the emulsion is subjected to negative pressure extraction at a condition of -0.07 to -0.09 MPa for 3-5 hours, and the product is filtered out, so that the acrylic emulsion for high-temperature odor-free thermal sublimation transfer paper is prepared.

[0055] The above preparation method controls the generation of odor from raw material sources, and solves the free VOC and small molecules by using a two-step method. The polymerization step is added in the temperature keeping stage, the temperature is increased, and the initiator is added dropwise to promote the effective polymerization of free monomers in the liquid phase. In addition, the high-temperature negative pressure extraction process is added to remove the residual small molecules and VOC from the latex after polymerization, purify the odor of the emulsion, and prevent the emulsion from volatilizing odor at high temperature. In the preparation process, the seed pre-emulsification semi-continuous dropping process is used, and the reaction in the polymerization system can be carried out more fully and stably, and the gel rate is low. The water bath is used as a heating medium, the heating source is convenient, and the circulation production can be realized.

[0056] In order to further illustrate the acrylic emulsion for high-temperature odor-free thermal sublimation transfer paper and the preparation method thereof provided by the present application, the following examples are provided.

[0057] Example 1

[0058] An acrylic emulsion for high-temperature odor-free thermal sublimation transfer paper comprises the following components by weight: 95 parts of deionized water, 36 parts of acrylic acid alkyl ester (18 parts of butyl acrylate and 18 parts of isooctyl acrylate), 29 parts of styrene, 13 parts of methyl methacrylate, 2.5 parts of unsaturated hydroxyl functional monomer (hydroxyethyl methacrylate), 1.3 parts of crosslinking monomer (trimethylolpropane trimethacrylate), 1.2 parts of reactive emulsifier (a compound product of anionic emulsifier (SR-20 and SR-30) and nonionic emulsifier (ER-10) at a weight ratio of 1:1.2), 1.3 parts of initiator (sodium persulfate), and 0.3 parts of pH regulator (sodium hydroxide).

[0059] The preparation method of the above emulsion comprises the following steps:

[0060] (1) Preparation of base liquid A: 47 parts of deionized water and 0.7 parts of reactive emulsifier are added into a polymerization kettle provided with a stirrer, a condenser and a constant flow pump feeding device, the kettle temperature is increased to 72℃, and stirring is carried out for 1.5 hours.

[0061] (2) Preparation of pre-emulsion B: At normal temperature and pressure, 18 parts of butyl acrylate, 18 parts of isooctyl acrylate, 29 parts of styrene, 13 parts of methyl methacrylate, 2.5 parts of hydroxyethyl methacrylate, 1.3 parts of trimethylolpropane trimethacrylate, 0.5 parts of reactive emulsifier, and 25 parts of deionized water were added to a pre-emulsion tank with a monomer metering tank and a stirrer to mix into a uniform pre-emulsion B, and stirring was continued for 20 minutes for standby use.

[0062] (3) Preparation of initiator solution C: At normal temperature and pressure, 0.7 parts of sodium persulfate and 8 parts of deionized water were added to an initiator tank with a stirrer and a constant-flow dropping device to prepare a uniform initiator solution C for standby use.

[0063] (4) Preparation of initiator solution D: At normal temperature and pressure, 0.6 parts of sodium persulfate and 15 parts of deionized water were added to an initiator tank to prepare a uniform initiator solution D for standby use.

[0064] (5) When the temperature in the polymerization kettle reached 72°C, 4% of pre-emulsion B by weight of pre-emulsion B and 12% of initiator solution C by weight of initiator solution C were added to the kettle, and after 20 minutes of reaction, the remaining pre-emulsion B and the remaining initiator solution C were simultaneously added to the polymerization kettle through a constant-flow pump feeding device and a constant-flow dropping metering device, and the titration time was controlled at 220 minutes.

[0065] (6) The temperature in the polymerization kettle was raised to 82°C, and the temperature was maintained for 1 hour.

[0066] (7) Initiator solution D was added to the polymerization kettle through a constant-flow pump feeding device, and the temperature in the polymerization kettle was controlled at 82°C, and the addition time was controlled at 120 minutes.

[0067] (8) After the addition of initiator solution D was completed, the temperature in the polymerization kettle was controlled at 80°C, and the temperature was maintained for 2 hours.

[0068] (9) The temperature in the polymerization kettle was lowered to 40°C, 0.3 parts of sodium hydroxide was added to the polymerization kettle, and stirring was continued for 0.5 hours; then the emulsion was subjected to negative pressure extraction at a condition of -0.07 to -0.09 MPa for 3 hours, and the filtered material was obtained, thereby obtaining the high-temperature odor-free thermal sublimation transfer paper acrylate emulsion.

[0069] Example 2

[0070] A high-temperature odorless thermal sublimation transfer paper acrylate emulsion, comprising the following components by weight: 101 parts of deionized water, 40 parts of alkyl acrylate (20 parts of isooctyl acrylate, 20 parts of octadecyl acrylate), 31 parts of styrene, 17 parts of methyl methacrylate, 3.5 parts of unsaturated hydroxyl functional monomer (hydroxyethyl acrylate), 2 parts of crosslinking monomer (1 part of glycidyl methacrylate, 1 part of ethylene glycol dimethacrylate), 2.2 parts of reactive emulsifier (a compound product of an anionic emulsifier (SR-10) and a nonionic emulsifier (ER-10, ER-20) in a weight ratio of 1:2), 2.5 parts of initiator (sodium persulfate), and 0.2 parts of pH regulator (sodium bicarbonate).

[0071] The preparation method of the above emulsion comprises the following steps:

[0072] (1) Preparation of base liquid A: add 50 parts of deionized water and 1 part of reactive emulsifier to a polymerization kettle equipped with a stirrer, a condenser, and a constant-flow pump feeding device, heat to a kettle temperature of 75°C, and stir for 1.5 hours.

[0073] (2) Preparation of pre-emulsion B: at normal temperature and pressure, add 20 parts of isooctyl acrylate, 20 parts of octadecyl acrylate, 31 parts of styrene, 17 parts of methyl methacrylate, 3.5 parts of hydroxyethyl acrylate, 1 part of glycidyl methacrylate, 1 part of ethylene glycol dimethacrylate, 1.2 parts of reactive emulsifier, and 29 parts of deionized water to a pre-emulsion tank equipped with a monomer metering tank and a stirrer, stir to mix into a uniform pre-emulsion B, and stir for 30 minutes for standby use.

[0074] (3) Preparation of initiator solution C: at normal temperature and pressure, add 1.1 parts of sodium persulfate and 10 parts of deionized water to an initiator tank equipped with a stirrer and a constant-flow dropping device, and prepare a uniform initiator solution C for standby use.

[0075] (4) Preparation of initiator solution D: at normal temperature and pressure, add 1.4 parts of sodium persulfate and 12 parts of deionized water to the initiator tank, and prepare a uniform initiator solution D for standby use.

[0076] (5) When the temperature in the polymerization kettle reaches 75°C, add 7% of the pre-emulsion B based on the weight of the pre-emulsion B and 15% of the initiator solution C based on the weight of the initiator solution C to the kettle, and after reacting for 30 minutes, simultaneously add the remaining pre-emulsion B and the remaining initiator solution C to the polymerization kettle through the constant-flow pump feeding device and the constant-flow dropping metering device, and control the titration time to be 300 minutes.

[0077] (6) Raise the temperature in the polymerization kettle to 85°C, and keep the temperature for 1 hour.

[0078] (7) The initiator solution D is added dropwise into the polymerization kettle by a constant flow pump feeding device, the temperature in the polymerization kettle is controlled at 85°C, and the dropwise adding time is controlled at 100 minutes.

[0079] (8) After the initiator solution D is added dropwise completely, the temperature in the polymerization kettle is controlled at 85°C, and the temperature is kept for 1.5 hours.

[0080] (9) The temperature in the polymerization kettle is decreased to 45°C, 0.2 parts of sodium bicarbonate is added into the polymerization kettle, and stirred for 0.5 hours; then the emulsion is subjected to negative pressure extraction under the condition of -0.07 to -0.09 MPa for 4 hours, and the product is filtered out, so that the acrylic emulsion for high-temperature odor-free thermal sublimation transfer paper is prepared.

[0081] Example 3

[0082] An acrylic emulsion for high-temperature odor-free thermal sublimation transfer paper comprises the following components in parts by weight: 106 parts of deionized water, 42 parts of acrylic alkyl ester (lauryl acrylate), 30 parts of styrene, 15 parts of methyl methacrylate, 5 parts of unsaturated hydroxyl functional monomer (2.5 parts of hydroxyethyl acrylate and 2.5 parts of hydroxyethyl methacrylate), 3 parts of crosslinking monomer (bicyclopentyl methacrylate), 2 parts of reactive emulsifier (a compound product of anionic emulsifier (SR-10, SR-20) and nonionic emulsifier (ER-10, ER-30) at a weight ratio of 1:1.5), 2 parts of initiator (potassium persulfate), and 0.5 part of pH regulator (sodium carbonate).

[0083] The preparation method of the above emulsion comprises the following steps:

[0084] (1) Preparation of base liquid A: 48 parts of deionized water and 1.3 parts of reactive emulsifier are added into a polymerization kettle provided with a stirrer, a condenser and a constant flow pump feeding device, the kettle temperature is increased to 78°C, and stirred for 1 hour.

[0085] (2) Preparation of pre-emulsion B: 42 parts of lauryl acrylate, 30 parts of styrene, 15 parts of methyl methacrylate, 2.5 parts of hydroxyethyl acrylate, 2.5 parts of hydroxyethyl methacrylate, 3 parts of bicyclopentyl methacrylate, 0.7 parts of reactive emulsifier and 28 parts of deionized water are added into a pre-emulsion tank provided with a monomer metering tank and a stirrer at normal temperature and pressure, and stirred and mixed to form a uniform pre-emulsion B, and stirred for 45 minutes for standby use.

[0086] (3) Preparation of initiator solution C: 1 part of potassium persulfate and 12 parts of deionized water are added into an initiator tank provided with a stirrer and a constant flow dropwise adding device at normal temperature and pressure, and stirred to form a uniform initiator solution C for standby use.

[0087] (4) Preparation of initiator solution D: 1 part of potassium persulfate and 18 parts of deionized water were added into an initiator tank at normal temperature and pressure to prepare a uniform initiator solution D for standby.

[0088] (5) When the temperature in the polymerization kettle reached 78℃, 6% of pre-emulsion B by weight of pre-emulsion B and 18% of initiator solution C by weight of initiator solution C were added into the kettle, and after 20 minutes of reaction, the remaining pre-emulsion B and the remaining initiator solution C were simultaneously added into the polymerization kettle through the constant flow pump feeding device and the constant flow dropping metering device, and the titration time was controlled for 270 minutes.

[0089] (6) The temperature in the polymerization kettle was raised to 88℃, and the temperature was maintained for 0.5 hours.

[0090] (7) The initiator solution D was added into the polymerization kettle through the constant flow pump feeding device, and the temperature in the polymerization kettle was controlled at 88℃, and the dropping time was controlled for 80 minutes.

[0091] (8) After the addition of the initiator solution D was completed, the temperature in the polymerization kettle was controlled at 88℃, and the temperature was maintained for 1 hour.

[0092] (9) The temperature in the polymerization kettle was lowered to 45℃, 0.5 parts of sodium carbonate was added into the polymerization kettle, and the mixture was stirred for 1 hour; then the emulsion was subjected to negative pressure extraction under the condition of -0.07 to -0.09 MPa for 5 hours, and the filtered material was obtained, thereby obtaining the high-temperature odor-free thermal sublimation transfer paper acrylate emulsion.

[0093] Comparative Example 1

[0094] The butyl benzene latex was purchased from Shengxiuo Company, and the model was Ligos F 3690.

[0095] Comparative Example 2

[0096] The acrylate emulsion was purchased from Chuanhua Chemical Industry Company, and the model was TS-1.

[0097] Comparative Example 3

[0098] A high-temperature odor-free thermal sublimation transfer paper acrylate emulsion, by weight, included the following components: 95 parts of deionized water, 18 parts of butyl acrylate, 18 parts of isooctyl acrylate, 29 parts of styrene, 13 parts of methyl methacrylate, 1.3 parts of trimethylolpropane trimethacrylate, 1.2 parts of a reactive emulsifier (a compound product of an anionic emulsifier (SR-20 and SR-30) and a nonionic emulsifier (ER-10) at a weight ratio of 1:1.2), 1.3 parts of sodium persulfate, and 0.3 parts of sodium hydroxide.

[0099] The preparation method of Comparative Example 3 is basically the same as that of Example 1, except that Comparative Example 3 does not add unsaturated hydroxyl functional monomer.

[0100] Comparative Example 4

[0101] An acrylate emulsion for high-temperature odorless thermal sublimation transfer paper includes, by weight parts, 95 parts of deionized water, 18 parts of butyl acrylate, 18 parts of isooctyl acrylate, 29 parts of styrene, 13 parts of methyl methacrylate, 2.5 parts of hydroxyethyl methacrylate, 1.2 parts of a reactive emulsifier (a compound product of an anionic emulsifier (SR-20 and SR-30) and a nonionic emulsifier (ER-10) at a weight ratio of 1:1.2), 1.3 parts of sodium persulfate, and 0.3 parts of sodium hydroxide.

[0102] The preparation method of Comparative Example 4 is basically the same as that of Example 1, except that Comparative Example 4 does not add a crosslinking monomer.

[0103] Test

[0104] The prepared emulsion is formulated into a thermal sublimation coating, and a laboratory blade coating method is used to control the coating amount to be 4-6 g / m2. The coating is dried in an oven with hot air for 30 seconds, and then calendered under the conditions of 40°C and a pressure of 49 KPa to obtain a test sample. The test sample is selected for a pattern by a thermal sublimation inkjet printer, and the printed pattern is subjected to a transfer experiment by a thermal transfer machine. The thermal transfer machine is set to a temperature of 200°C, a time of 30 seconds, and a pressure of 98 KPa.

[0105] Test items:

[0106] 1. Printing quality: Subjectively evaluate the ink absorption speed, ink piling phenomenon, and bleeding phenomenon of the paper.

[0107] 2. Transfer quality: Print an image under the same inkjet printer and the same printing mode, and then evaluate the paper transfer quality according to the amount of residual ink on the paper (average value of CMYK four-color optical densities), the average value of the optical densities of the CMYK four-color blocks of the transferred product, and the overall effect of the transferred image.

[0108] 3. Odor detection: The coating amount is controlled to be 1 g / m2, and the emulsion is prepared into a blank paper. After drying, the headspace HS-GCMS method (pressure 0.8 MPa, time 30 seconds, temperature 200°C) is used to test the quantitative value of volatile substances in the experimental sample, and the odor is evaluated.

[0109] Table 1 shows the performance test results of the thermal sublimation transfer paper prepared in Examples 1-3 and Comparative Examples 1-4.

[0110]

[0111]

[0112] Note: ① Ink piling phenomenon, absorption speed, bleeding and overall effect of the image are indicated by "*" and the more "*" is, the less ink piling phenomenon is, the faster absorption speed is, the less bleeding phenomenon is and the better overall printing effect is.

[0113] ② The overall effect of the odor is indicated by "●" and the more "●" is, the better odor effect is.

[0114] From the above table, it can be seen that the volatile content of the butyl rubber latex of Comparative Example 1 and the acrylate emulsion of Comparative Example 2 at high temperature (200℃) is much greater than that of the emulsion prepared in Examples 1-3, and is accompanied by a large amount of release of bad odor, which is not conducive to green and sustainable development. And the density value of the thermal sublimation transfer paper prepared by Comparative Example 1 and Comparative Example 2 is low, the amount of residual ink is large, and the printing quality of the product is also poor, and the definition is not as good as the printing quality of Examples 1-3.

[0115] Comparative Example 3 cannot provide hydroxyl functional groups, and the adhesion of the emulsion coating to the paper is poor, and the hydrogen bond cannot be riveted with the thermal sublimation ink, resulting in ink piling and diffusion after transfer, reducing the printing quality and transfer quality of the product.

[0116] From the above table, it can be seen that the influence of the crosslinking monomer in Comparative Example 4 on the printing and transfer quality of the product is less than that of the hydroxyl functional monomer, but the emulsion without adding crosslinking monomer reduces the crosslinking degree of the emulsion, and the density value of the coating is reduced, and the product after printing still has problems such as ink piling, line diffusion and reducing definition.

[0117] In summary, the emulsion of the present application applied to the thermal sublimation transfer paper has good temperature resistance. The generation of odor of the emulsion is controlled from the source of the material, and the two-step method is used to solve free VOC and small molecules, promote monomer polymerization, and achieve the effect of net odor at high temperature. And it can ensure the printing quality and transfer quality of the transfer paper.

[0118] It can be understood that for those skilled in the art, equivalent replacements or changes can be made according to the technical solutions and inventive concepts of the present application, and all such changes or replacements shall belong to the protection scope of the present application.

Claims

1. A high temperature odor-free thermal sublimation transfer paper acrylate emulsion characterized in that, By weight parts, including the following components: 92-110 parts of deionized water, 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of unsaturated hydroxyl functional monomer, 1-3 parts of crosslinking monomer, 1.0-2.5 parts of reactive emulsifier, 1-2.5 parts of initiator, and 0.2-0.5 parts of pH regulator; the alkyl acrylate includes one or more of butyl acrylate, isooctyl acrylate, lauryl acrylate, and stearyl acrylate; the unsaturated hydroxyl functional monomer includes one or more of hydroxyethyl acrylate and hydroxyethyl methacrylate; the crosslinking monomer includes one or more of glycidyl methacrylate, dicyclopentenyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

2. The high temperature odor-free thermal dye sublimation transfer paper acrylate emulsion according to claim 1, characterized in that, The reactive emulsifier is a product compounded by a reactive anionic emulsifier and a reactive nonionic emulsifier; the reactive anionic emulsifier includes one or more of SR-10, SR-20, and SR-30 of Addicor; the reactive nonionic emulsifier includes one or more of ER-10, ER-20, and ER-30 of Addicor.

3. The high temperature odor-free thermal dye sublimation transfer paper acrylate emulsion according to claim 2, characterized in that, The weight ratio of the reactive anionic emulsifier to the reactive nonionic emulsifier is 1:(1-2.5).

4. The high temperature odorless thermal dye sublimation transfer paper acrylate emulsion of claim 1, wherein, The initiator includes one or more of sodium persulfate and potassium persulfate.

5. The high temperature odorless thermal dye sublimation transfer paper acrylate emulsion of claim 1, wherein, The pH regulator includes one or more of sodium hydroxide, sodium bicarbonate, and sodium carbonate.

6. A process for the preparation of a high temperature clean taste thermal dye sublimation transfer paper acrylate emulsion according to any one of claims 1 to 5, characterized in that, Including the following steps: Preparation of the base liquid A: 47-51 parts of deionized water, 0.7-1.3 parts of the reactive emulsifier are added to the polymerization kettle, the temperature is raised to 70-80℃, and stirring is performed for 1-2 hours; Preparation of the pre-emulsion B: 36-43 parts of alkyl acrylate, 28-31 parts of styrene, 12-17 parts of methyl methacrylate, 2-5 parts of the unsaturated hydroxyl functional monomer, 1-3 parts of the crosslinking monomer, 0.3-1.2 parts of the reactive emulsifier, and 25-29 parts of deionized water are added to the pre-emulsion tank at normal temperature and pressure, and stirring is performed to mix into a uniform pre-emulsion B for standby; Preparation of the initiator solution C: 0.6-1.1 parts of the initiator and 8-12 parts of deionized water are added to the initiator tank at normal temperature and pressure to prepare a uniform initiator solution C for standby; Preparation of the initiator solution D: 0.4-1.4 parts of the initiator and 12-18 parts of deionized water are added to the initiator tank at normal temperature and pressure to prepare a uniform initiator solution D for standby; When the temperature in the polymerization kettle reaches 70-80℃, 4-8% of the pre-emulsion B based on the weight of the pre-emulsion B and 12-18% of the initiator solution C based on the weight of the initiator solution C are added to the kettle, and after reaction for 10-30 minutes, the remaining pre-emulsion B and the remaining initiator solution C are simultaneously added dropwise to the polymerization kettle, and the titration time is controlled to be 220-300 minutes; The temperature in the polymerization kettle is raised to 80-90℃, and the temperature is maintained; The initiator solution D is added dropwise to the polymerization kettle, and the temperature in the polymerization kettle is controlled to be 80-90℃, and the dropwise addition time is controlled to be 80-120 minutes; After the dropping of the initiator solution D is completed, the temperature in the polymerization kettle is controlled at 80-90 DEG C, and the temperature is kept for 1-2 hours; The temperature in the polymerization kettle is decreased to 40-50 DEG C, 0.2-0.5 parts of pH regulator is added into the polymerization kettle, and the mixture is stirred for 0.5-1 hour; the product is filtered, and the acrylic ester emulsion of the high-temperature clean taste thermal sublimation transfer paper is prepared.

7. The method of making a high temperature odor-free thermal dye sublimation transfer paper acrylate emulsion according to claim 6, wherein, After the pH regulator is added and the stirring is completed, the emulsion is subjected to negative pressure extraction under the condition of-0.07 to-0.09 MPa for 3-5 hours.

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