Preparation process of rosin modified acrylic acid solid resin

Abstract

The invention discloses a preparation process of rosin modified acrylic acid solid resin. The preparation process comprises the following steps: esterifying refined rosin and an acrylic acid functional monomer in the presence of a catalyst and a polymerization inhibitor by using a solid-phase synthesis method to obtain a polymerizable rosin functional monomer; then adopting a semi-continuous solution polymerization method to obtain an acrylic resin solution with the solid content of 30-60%; then carrying out vacuum distillation to obtain an acrylic resin concentrated solution with the solid content exceeding 60%; and continuously extruding the acrylic resin concentrated solution to discharge solids, granulating to obtain low-VOC rosin modified acrylic resin particles, and separating the solvent in the concentrated solution from the unreacted residual polymerizable rosin functional monomer. The process flow is simple, safe and reliable, the production efficiency is high, the product manufacturing cost is low, VOC is low, and the rosin modified acrylic acid solid resin which has good adhesive force to PE and PP and good wetting dispersity to organic pigments can be obtained, and the acid value, the Tg value, the molecular weight and the molecular weight distribution can be adjusted and controlled.

Description

Technical Field

[0002] The invention belongs to the technical field of solid resin preparation methods, in particular to a preparation process of rosin-modified acrylic solid resin with low VOC and good adhesion to PE and PP. Background Art

[0004] With the development of petrochemical industry in my country, the synthesis process of acrylic acid monomer has become more mature, and the output of acrylic acid monomer has increased significantly. Acrylic resin is the most widely used and fastest growing type of synthetic resin in my country in recent years. It is widely used in coating industry, printing ink, packaging industry, etc. The advantages of solid acrylic resin are first of all convenient storage and transportation, the transportation cost is correspondingly lower than that of solvent-based acrylic resin, and the storage and transportation process is safe; secondly, there are many varieties of solid acrylic resin. Some solid acrylic resins can be used to produce water-based paints, water-based inks, UV curing coatings and high-solid coatings, which meet the development needs of coating industry, printing industry and packaging industry. At present, most of the polymerization methods of solid acrylic ester polymers in China are suspension polymerization water washing method, solution polymerization high temperature dry distillation method, emulsion polymerization coagulation method and bulk polymerization method. Many foreign companies have introduced solid acrylic resins into the Chinese market, with many varieties and specifications, and each company's products have their own characteristics, which not only enriches the raw materials of my country's coating industry, printing industry and packaging industry, but also greatly promotes the research and development of domestic solid acrylic resins. In order to be suitable for coatings, printing and packaging for different purposes, solid acrylic resins have a wide range of options in terms of solvents, viscosity adjustment, hardness, flexibility, chemical resistance, weather resistance, etc. Even the combination of several solid acrylic resins has greater flexibility than ordinary solvent-based acrylic resins, which is conducive to the research and development of new varieties of coatings, inks and adhesives. At present, most of the solid acrylic resins on the Chinese market are mainly methacrylate monomers.

[0005] The advantages and disadvantages of the existing solid acrylic acid synthesis process methods are compared as follows: 1. Advantages of emulsion polymerization: easy heat dissipation, continuous polymerization, relatively stable reaction, good safety; Disadvantages: some emulsifiers and other additives remain in the product, the purity is not high, and a large amount of water is used during washing and drying, which pollutes the environment and consumes a lot of energy. 2. Advantages of suspension polymerization: easy heat dissipation and intermittent production; Disadvantages: some dispersants and other additives remain in the product, the purity is not high, the reaction is not easy to control, and separation, washing, drying and other procedures are required, which are relatively complicated, with a large amount of water, pollution of the environment, and high energy consumption. 3. Advantages of bulk polymerization: the polymer is pure and suitable for the production of transparent and light-colored products; the equipment is relatively simple; Disadvantages: difficult to dissipate heat, easy to explode during polymerization, and poor safety.

[0006] The existing published patents involving the synthesis and preparation methods of solid acrylic resin mainly include:

[0007] A method for synthesizing an alkali-soluble solid styrene-acrylic resin (Application No. ), the method is to add part of the mixed monomer, part of the initiator, and part of the molecular weight regulator to the solvent under the protection of N2, stir to make them fully mixed, and obtain solution A; mix the remaining mixed monomer, part of the initiator and the remaining molecular weight regulator, and stir to obtain solution B; the remaining initiator is solution C; after adding solution A to a stirred atmospheric pressure reactor under N2 atmosphere, quickly heat it to 100-150°C, drip solution B at a uniform speed, and add C once more after dripping, and obtain a polymer solution after reaction; the precipitated solid polymer is filtered and dried to obtain a solid styrene-acrylic resin. The present invention uses styrene and acrylic acid as the main raw materials and dimethylformamide as the solvent to synthesize a styrene-acrylic resin with controllable molecular weight, narrow molecular weight distribution, and adjustable glass transition temperature, and the reaction yield is relatively high. However, the final product of this method has a large amount of residual monomers and a strong odor.

[0008] Water-based ink based on synthetic water-based solid acrylic resin and its preparation method (Patent No. ) With acrylic acid mixed monomer as comonomer, ammonium persulfate as initiator, water as reaction medium, water phase suspension copolymerization reaction is carried out under stirring to obtain water-based solid acrylic resin; water, cosolvent and amine are used to dissolve the water-based solid acrylic resin, and then pigment, water and additives are added, and the water-based ink is made by grinding with a sand mill. The product of the present invention has the characteristics of being non-toxic, pollution-free, non-flammable, non-explosive, safe to use, high concentration, small dosage, stable performance, good printing adaptability, strong adhesion, fast drying, no harmful residual substances after the printed matter is dried, excellent water resistance and wear resistance, no fading, low manufacturing cost, etc. However, this method has poor wettability for pigments.

[0009] A method for preparing a water-soluble solid styrene / acrylic resin and its application (Application No. )This method is to place aromatic vinyl unsaturated monomers, aliphatic vinyl unsaturated monomers, unsaturated carboxylic acid monomers, fatty alkanols, initiators and α-methylstyrene dimers in a reactor, and simultaneously carry out free radical polymerization and esterification to prepare the desired resin. The present invention adds α-methylstyrene dimer as a chain transfer agent, which reduces the degree of branching, avoids the generation of gel and the blockage of the reactor; the fatty alkanol added at the same time reacts with acrylic acid to undergo esterification, inhibits the esterification reaction of alcohol ether solvent and acrylic acid, and can effectively control the viscosity of the reaction mixture. The resin finally prepared has a narrower molecular weight distribution (MW / Mn<2.0), a lower molecular weight (MW<10000), less organic volatiles, and good wetting and dispersibility for pigments, and can be used to prepare water-based inks, coatings or varnishes. However, the product of this method has poor adhesion to films.

[0010] A method for preparing a water-soluble solid styrene-acrylate resin (Application No. ) Preparation method: Under normal pressure and low temperature, with N2 atmosphere as protective gas, using normal pressure semi-continuous solution polymerization process, using peroxide as initiator, mercapto acid substances as chain transfer agent, through α-methylstyrene (AMS) or / and styrene (St), acrylate monomers, acrylic acid (AA) multi-polymerization, a water-soluble solid styrene-acrylic resin with adjustable weight average molecular weight (MW), acid value and glass transition temperature (Tg) can be obtained. The polymerization process of this method is simple, the normal pressure environment and the temperature are low, the acid value and Tg value are controllable, and the polymerization process is simple; the polymerization reaction is in a normal pressure environment and the temperature is low (110-120℃), which is safe and energy-saving for production. However, the product of this method also has poor adhesion to the film. Summary of the invention

[0012] The purpose of the invention is to solve the deficiencies of the above-mentioned prior art and to provide a preparation process for a rosin-modified acrylic solid resin with a simple, safe and reliable process flow, high production efficiency, low product manufacturing cost, low VOC (volatile organic gas), good adhesion to PE and PP, good wetting and dispersibility to organic pigments, and adjustable and controllable acid value, Tg value (glass transition temperature), molecular weight and molecular weight distribution.

[0013] The technical solution adopted by the present invention is as follows:

[0014] A preparation process of rosin modified acrylic solid resin comprises the following steps: firstly, a solid phase synthesis method is used to esterify refined rosin and acrylic functional monomer in the presence of a catalyst and an inhibitor to obtain a polymerizable rosin functional monomer with a solid content greater than 98%; then a semi-continuous solution polymerization method is used to obtain an acrylic resin solution with a solid content of 30-60%; then vacuum distillation is performed to obtain an acrylic resin concentrated solution with a solid content of more than 60%; then the acrylic resin concentrated solution is continuously extruded to discharge solids, and at the same time, the solvent and unreacted residual polymerizable rosin functional monomer in the acrylic resin concentrated solution are separated, and the discharged solids are granulated to obtain rosin modified acrylic resin particles with a VOC index of less than 50 ppm.

[0015] The method for obtaining a polymerizable rosin functional monomer by the solid phase synthesis method of the present invention is as follows:

[0016] (1.1) Take refined rosin and acrylic acid functional monomer according to the mass ratio, 40-70% of refined rosin, 30-60% of acrylic acid functional monomer, and the total mass of refined rosin and acrylic acid functional monomer is 100%; then take 0.5-5% of the mass of refined rosin as catalyst and 0-4% of the mass of acrylic acid functional monomer as inhibitor;

[0017] (1.2) Put the refined rosin into the reactor, slowly raise the temperature to 150-180°C, add the catalyst and inhibitor after the refined rosin is melted, then uniformly add the acrylic acid functional monomer to the reactor within 1-4 hours, and then react at 180-230°C to obtain a polymerizable rosin functional monomer with a solid content greater than 98%;

[0018] The semi-continuous solution polymerization method for obtaining an acrylic resin solution with a solid content of 30 to 60% by the semi-continuous solution polymerization method is as follows:

[0019] (2.1) Adding 1 to 4 times the mass of acrylate monomer to the prepared polymerizable rosin functional monomer to obtain a composite functional body;

[0020] (2.2) Take the composite functional body and the solvent according to the mass ratio, the composite functional body is 40-60%, the solvent is 40-60%, and the total mass of the composite functional body and the solvent is 100%; then take an initiator of 2-8% of the mass of the composite functional body and a chain transfer agent of 0-4% of the mass of the composite functional body;

[0021] (2.2) First, take a portion of the solvent, add the composite functional body, a portion of the initiator and the chain transfer agent into the solvent, and stir and mix them thoroughly to obtain a mixed monomer composite solution;

[0022] (2.4) adding a portion of the solvent into a stirred reactor, raising the temperature to solvent reflux for 10 to 15 minutes under normal pressure, maintaining the temperature for 15 to 30 minutes after reflux and temperature stabilization, and then dripping the mixed monomer composite solution at a uniform rate for 2 to 4 hours;

[0023] (2.5) After the mixed monomer composite solution is added dropwise, the remaining solvent and initiator are added and the mixture is kept warm for 1 to 2 hours to obtain an acrylic polymer solution with a solid content of 30 to 60%.

[0024] Preferably, the acrylic functional monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0025] Preferably, the catalyst is one or more of zinc oxide, zinc chloride, zinc nitrate and zinc acetate.

[0026] Preferably, the polymerization inhibitor is one or both of hydroquinone and anthraquinone.

[0027] Preferably, the solvent is one or more of ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethyl acetate, and butyl acetate.

[0028] Preferably, the initiator is one or more of azobisisobutyronitrile, azobisisoheptylnitrile, benzoyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy(2-ethyl)hexanoate, tert-butyl peroxyformate, tert-butyl peroxide, tert-butyl hydroperoxide and tert-amyl hydroperoxide.

[0029] Preferably, the chain transfer agent is one or more of dodecyl mercaptan, 2-mercaptoethanol, aliphatic mercaptan, and 2,4-diphenyl-4-methyl-1-pentene.

[0030] Preferably, the acrylic acid ester monomer is one or more of methyl methacrylate, butyl acrylate, isooctyl acrylate, acrylic acid, methacrylic acid, styrene, hydroxyethyl acrylate, hydroxypropyl acrylate, butyl methacrylate, and vinyl acetate.

[0031] The present invention provides a method for continuously extruding a concentrated acrylic resin solution to discharge solids and separating the solvent and unreacted residual polymerizable rosin functional monomers in the concentrated acrylic resin solution by using a twin-screw exhaust extruder equipped with a two-stage condensation collection device. The twin-screw exhaust extruder equipped with the two-stage condensation collection device comprises a twin-screw exhaust extruder, a primary condensation collection device and a secondary condensation collection device sequentially arranged along the twin-screw exhaust extruder; the primary condensation collection device comprises a primary solvent cooler and a primary solvent collector, the inlet of the primary solvent cooler is connected to a first-stage solvent cooler on the twin-screw exhaust extruder through a pipeline. The first-stage condensation collection device comprises a second-stage solvent cooler and a second-stage solvent collector, the inlet of the second-stage solvent cooler is connected to the plurality of outlet holes opened in the rear section of the barrel of the twin-screw exhaust extruder through a pipeline, the outlet of the second-stage solvent cooler is connected to the inlet of the second-stage solvent collector through a pipeline, and the outlet of the second-stage solvent collector is connected to the discharge pipeline equipped with a second-stage vacuum pump; the feed port of the twin-screw exhaust extruder is connected to the reactor through a pipeline.

[0032] The present invention has the following beneficial effects:

[0033] 1. The process flow of the present invention is simple and reliable, the production efficiency is high, the product manufacturing cost is low, and the production efficiency is high.

[0034] 2. The present invention introduces the unique phenanthrene ring structure of rosin into the solid resin. The obtained resin has extremely low VOC, excellent adhesion to PE and PP, and excellent wetting and dispersibility to most organic pigments.

[0035] 3. The catalyst in the present invention can accelerate the esterification reaction, and the inhibitor can ensure that only the esterification reaction occurs without the polymerization reaction; the prepared polymerized rosin functional monomer can play a role in regulating the molecular weight by continuing to add an initiator and a chain transfer agent to the polymerization reaction.

[0036] 4. The preparation process of the present invention is unique. First, a solid phase synthesis method is used to esterify refined rosin and acrylic acid functional monomers in the presence of a catalyst and an inhibitor to obtain a polymerizable rosin functional monomer; then a semi-continuous solution polymerization method is used to obtain an acrylic resin solution, and in the process of preparing the acrylic resin solution, a solvent and an initiator are added step by step to first prepare a mixed monomer composite solution, and then the mixed monomer composite solution is added dropwise into the solvent, and finally the remaining solvent and initiator are added to prepare an acrylic polymer solution.

[0037] 5. The process of the present invention can produce a variety of resin products, and the variety replacement is quick and convenient, and the acid value, Tg value, molecular weight, and molecular weight distribution of the obtained products can be controlled.

[0038] 6. The resin product prepared by the present invention has a wide range of application scenarios and can be used in coatings, inks, adhesives, and can meet the requirements of solid resins for the food, tobacco, home appliances, home decoration and other industries. It is particularly suitable for raw materials for tobacco, medical and food packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of a device for extruding a concentrated acrylic resin solution in the method of the present invention. DETAILED DESCRIPTION

[0042] The following embodiments may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0043] The preparation process of the rosin modified acrylic solid resin of the present invention comprises the following steps: firstly, a solid phase synthesis method is used to esterify refined rosin and acrylic functional monomers in the presence of a catalyst and a polymerization inhibitor to obtain a polymerizable rosin functional monomer with a solid content greater than 98%; then a semi-continuous solution polymerization method is used to obtain an acrylic resin solution with a solid content of 30-60%; then vacuum distillation is performed to obtain an acrylic resin concentrated solution with a solid content exceeding 60%; then a continuous extrusion exhaust device is used to continuously extrude the acrylic resin concentrated solution to discharge solids, and at the same time, the solvent and unreacted residual polymerizable rosin functional monomers in the acrylic resin concentrated solution are separated, and the discharged solids are granulated to obtain low-VOC rosin modified acrylic resin particles.

[0044] The method of obtaining a polymerizable rosin functional monomer by solid phase synthesis is as follows;

[0045] (1) According to the mass ratio, weigh 40-70% of refined rosin and 340-60% of acrylic acid functional monomer, and the total mass of refined rosin and acrylic acid functional monomer is 100%; then weigh 0.5-5% of the mass of refined rosin catalyst and 0-4% of the mass of acrylic acid functional monomer inhibitor. The refined rosin can be directly purchased from the market. The acrylic acid functional monomer can be one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl acrylate, and glycidyl methacrylate. The catalyst can be one or more of zinc oxide, zinc chloride, zinc nitrate, and zinc acetate. The inhibitor is one or two of hydroquinone and anthraquinone.

[0046] (2) Put the refined rosin into the reactor, slowly raise the temperature to 150-180°C, add the catalyst and the inhibitor after the refined rosin is melted, then uniformly add the acrylic acid functional monomer to the reactor within 1-4 hours, and then react at 180-230°C to obtain a polymerizable rosin functional monomer with a solid content greater than 98%;

[0047] The semi-continuous solution polymerization method for obtaining an acrylic resin solution having a solid content of 30 to 60% by semi-continuous solution polymerization is as follows:

[0048] (1) According to the mass ratio, add acrylate monomer to the prepared polymerizable rosin functional monomer to obtain a composite functional body, weigh 40-60% of the composite functional body and 40-60% of the solvent, and the total mass of the composite functional body and the solvent is 100%; then weigh 2-8% of the mass of the composite functional body as an initiator, and 0-4% of the mass of the composite functional body as a chain transfer agent. The solvent includes but is not limited to one or more of ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethyl acetate, and butyl acetate. The initiator includes but is not limited to one or more of azobisisobutyronitrile, azobisisoheptylnitrile, benzoyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy(2-ethyl)hexanoate, tert-butyl peroxyformate, tert-butyl peroxide, tert-butyl hydroperoxide, and tert-amyl hydroperoxide. The chain transfer agent includes but is not limited to one or more of dodecyl mercaptan, 2-mercaptoethanol, aliphatic mercaptan, and 2,4-diphenyl-4-methyl-1-pentene. The acrylate monomer includes but is not limited to one or more of methyl methacrylate, butyl acrylate, isooctyl acrylate, acrylic acid, methacrylic acid, styrene, hydroxyethyl acrylate, hydroxypropyl acrylate, butyl methacrylate, and vinyl acetate.

[0049] (2) first taking a portion of the solvent, adding the composite functional body, a portion of the initiator and the chain transfer agent into the solvent, and fully stirring and mixing to obtain a mixed monomer composite solution;

[0050] (3) adding a portion of the solvent into a stirred reactor, raising the temperature to solvent reflux for 10 to 15 minutes under normal pressure, maintaining the temperature for 15 to 30 minutes after reflux and temperature stabilization, and then dripping the mixed monomer composite solution at a uniform rate for 2 to 4 hours;

[0051] (4) After the mixed monomer composite solution is added dropwise, the remaining solvent and initiator are added and the mixture is kept warm for 1 to 2 hours to obtain an acrylic polymer solution with a solid content of 30 to 60%.

[0052] The continuous extrusion exhaust device used in the process of the present invention is as follows Figure 1 The twin-screw venting extruder equipped with a two-stage condensation collection device shown in the figure comprises a twin-screw venting extruder 1, a primary condensation collection device and a secondary condensation collection device sequentially arranged along the twin-screw venting extruder. The primary condensation collection device comprises a primary solvent cooler 2 and a primary solvent collector 3, the inlet of the primary solvent cooler is connected to a plurality of outlet holes opened in the front section of the barrel of the twin-screw venting extruder through a pipeline, the outlet of the primary solvent cooler is connected to the inlet of the primary solvent collector through a pipeline, and the outlet of the primary solvent collector is connected to a discharge pipeline equipped with a primary vacuum pump 4. The secondary condensation collection device comprises a secondary solvent cooler 5 and a secondary solvent collector 6, the inlet of the secondary solvent cooler is connected to a plurality of outlet holes opened in the rear section of the barrel of the twin-screw venting extruder through a pipeline, the outlet of the secondary solvent cooler is connected to the inlet of the secondary solvent collector through a pipeline, and the outlet of the secondary solvent collector is connected to a discharge pipeline equipped with a secondary vacuum pump 7; the feed port of the twin-screw venting extruder is connected to a reactor 8 through a pipeline.

[0053] Embodiment 1

[0054] A preparation process of rosin-modified acrylic solid resin. 100 kg of refined rosin is put into a reactor, and the temperature is slowly raised to about 180°C. After the rosin is melted, 1 kg of zinc oxide and 0.2 kg of hydroquinone are added, and then 43 kg of hydroxyethyl methacrylate is uniformly added to the reactor within 2 hours, and then the reaction is continued at 220°C for another 2 hours to obtain a product, a polymerizable rosin functional monomer. Then 280 kg of styrene, 10 kg of butyl acrylate, 90 kg of acrylic acid, and a polymerizable rosin functional monomer are mixed to obtain a composite functional body. The composite functional body and 15 kg of azobisisobutyronitrile are added to 100 kg of propylene glycol monomethyl ether, and stirred to fully mix to obtain a mixed monomer composite solution. Then 100 kg of propylene glycol monomethyl ether is added to Figure 1In the reactor 8 with a stirring device, under normal pressure, the temperature is raised to the solvent reflux for 15 minutes, and the temperature is kept for 20 minutes after reflux and temperature stabilization. The mixed monomer composite solution is added dropwise to the reactor at a uniform rate for 3 hours. After the addition is completed, 5 kg of azobisisobutyronitrile and 300 kg of propylene glycol monomethyl ether are added at once, and the temperature is kept for 2 hours to obtain an acrylic resin solution with a solid content of 50%. In the reactor, after distillation at 700 mmHg vacuum and 130° C., about 375 kg of propylene glycol monomethyl ether is recovered to obtain a concentrated acrylic resin solution with a solid content of 80%. The concentrated acrylic resin solution is added to a twin-screw exhaust extruder 1 through a pipeline provided with a metering pump 9. During the extrusion process, the solvent and unreacted residues are continuously discharged in sections. First, they are continuously collected at multiple positions of the barrel of the twin-screw exhaust extruder by a primary condensation and collection device for initial desorption. After condensation by a primary solvent cooler 2 and collection by a primary solvent collector 3, they are discharged by a primary vacuum pump 4. Then, they are continuously collected at multiple positions of the barrel of the twin-screw exhaust extruder by a secondary condensation and collection device for fine desorption. After condensation by a secondary solvent cooler 5 and collection by a secondary solvent collector 6, they are discharged by a secondary vacuum pump 7. The solvent and unreacted residues are completely desorbed and recovered. The solid obtained by extrusion is discharged to the cooling belt 10 for cooling, and then sent to the granulator 11 to obtain rosin-modified acrylic solid resin particles. The performance indicators of the resin particles are shown in Table 1.

[0055] Example 2

[0056] A preparation process of rosin-modified acrylic solid resin. 100 kg of refined rosin is added into a reactor, and the temperature is slowly raised to 150°C. After the rosin is melted, 1 kg of zinc chloride, 1 kg of zinc acetate, and 0.5 kg of anthraquinone are added. Then, 50 kg of hydroxyethyl acrylate and 50 kg of hydroxypropyl methacrylate are uniformly added to the reactor within 4 hours, and then reacted at 230°C for another 2 hours to obtain a polymerizable rosin functional monomer with a solid content greater than 98%. Then, 130 kg of methyl methacrylate, 140 kg of butyl methacrylate, 90 kg of methacrylic acid, and a polymerizable rosin functional monomer are mixed to obtain a composite functional body. The composite functional body, 40 kg of azobisisoheptonitrile, and 10 kg of dodecyl mercaptan are added to 100 kg of ethanol with a mass concentration of 98%, and stirred to fully mix to obtain a mixed monomer composite solution. After adding 100 kg of ethanol to a stirred reactor, the temperature was raised to solvent reflux for 12 minutes under normal pressure. After reflux and temperature stabilization, the temperature was kept for 30 minutes, and the mixed monomer composite solution was added dropwise at a constant speed for 4 hours. After the dripping was completed, 6.5 kg of azobisisoheptanitrile and 300 kg of ethanol were added at once, and the temperature was kept for 1.5 hours to obtain an acrylic polymer solution with a solid content of 60%. In the reactor, part of the ethanol was evaporated by distillation to obtain an acrylic resin concentrated solution with a solid content of 85%. The acrylic resin concentrated solution was sent to a twin-screw exhaust extruder, and the ethanol and unreacted residues were continuously discharged in sections. The solids obtained by extrusion were discharged and cooled and sent to granulation to obtain rosin-modified acrylic solid resin particles. The performance indicators of the resin particles are shown in Table 1.

[0057] Example 3

[0058] A preparation process of rosin-modified acrylic solid resin. 100 kg of refined rosin is put into a reactor, and the temperature is slowly raised to about 170°C. After the rosin is melted, 5 kg of zinc nitrate, 5 kg of hydroquinone, and 1 kg of anthraquinone are added. Then, 100 kg of hydroxypropyl methacrylate and 50 kg of glycidyl methacrylate are uniformly added to the reactor within 4 hours, and then the reaction is continued at 180°C for another 2 hours to obtain a polymerizable rosin functional monomer with a solid content greater than 98%. Then, 240 kg of styrene and 150 kg of isooctyl acrylate are added to the polymerizable rosin functional monomer, and the mixture is stirred evenly to obtain a composite functional body. The composite functional body, 10 kg of benzoyl peroxide, and 26 kg of 2-mercaptoethanol are added to 200 kg of isopropanol, and the mixture is stirred to be fully mixed to obtain a mixed monomer composite solution. After adding 200 kg of isopropanol into a stirred reactor, the temperature was raised to solvent reflux for 10 minutes under normal pressure, and the temperature was kept for 15 minutes after reflux and temperature stabilization, and the mixed monomer composite solution was added dropwise at a constant speed for 3 hours. After the dripping was completed, 3.5 kg of benzoyl peroxide and 200 kg of isopropanol were added at once, and the temperature was kept for 2 hours to obtain an acrylic polymer solution with a solid content of 35%; in the reactor, after distillation, an acrylic resin concentrated solution with a solid content of more than 80% was obtained. The acrylic resin concentrated solution was sent to a twin-screw exhaust extruder, and the isopropanol and unreacted residues were continuously discharged in sections. The solids obtained by extrusion were discharged and cooled and sent to granulation to obtain rosin-modified acrylic solid resin particles. The performance indicators of the resin particles are shown in Table 1.

[0059] Example 4

[0060] A preparation process of rosin-modified acrylic solid resin. 100 kg of refined rosin is put into a reactor, and the temperature is slowly raised to about 180°C. After the rosin is melted, 2 kg of zinc oxide and 1 kg of hydroquinone are added, and 50 kg of hydroxyethyl methacrylate is uniformly added to the reactor within 1 hour, and then the reaction is continued at 220°C for another 2 hours to obtain a polymerizable rosin functional monomer with a solid content greater than 98%. Then 375 kg of methyl methacrylate and 10 kg of butyl methacrylate are added to the polymerizable rosin functional monomer to obtain a composite functional body, and 10 kg of benzoyl peroxide is added to 100 kg of propylene glycol monomethyl ether, and stirred to fully mix to obtain a mixed monomer composite solution. After adding 100 kg of propylene glycol monomethyl ether into a stirred reactor, the temperature was raised to solvent reflux for 15 minutes under normal pressure. After reflux and temperature stabilization, the temperature was kept for 20 minutes, and the mixed monomer composite solution was added dropwise at a uniform rate for 2 hours. After the dripping was completed, 5 kg of benzoyl peroxide and 300 kg of propylene glycol monomethyl ether were added at once, and the temperature was kept for 1 hour to obtain an acrylic polymer solution with a solid content of 50%. In the reactor, under the conditions of 700 mmHg vacuum and 130°C, part of the propylene glycol monomethyl ether was distilled out to obtain an acrylic resin concentrated solution with a solid content of 80%. The acrylic resin concentrated solution was sent to a twin-screw exhaust extruder, and the propylene glycol monomethyl ether and unreacted residues were continuously discharged in sections. The extruded solids were discharged and cooled and sent to granulation to obtain rosin-modified acrylic solid resin particles. The performance indicators of the resin particles are shown in Table 1.

[0061] Example 5

[0062] A preparation process of rosin-modified acrylic solid resin. 100 kg of refined rosin is added into a reactor, and the temperature is slowly raised to about 160°C. After the rosin is melted, 3 kg of zinc acetate and 2 kg of hydroquinone are added. Then 100 kg of glycidyl acrylate is uniformly added to the reactor within 2 hours, and then the reaction is continued at 200°C for another 2 hours to obtain a polymerizable rosin functional monomer with a solid content greater than 98%. Then 180 kg of methyl methacrylate, 280 kg of styrene, and 40 kg of butyl acrylate are added to the polymerizable rosin functional monomer to obtain a composite functional body, and 15 kg of benzoyl peroxide is added to 100 kg of propylene glycol monomethyl ether, and stirred to fully mix to obtain a mixed monomer composite solution. After adding 200 kg of propylene glycol monomethyl ether into a stirred reactor, the temperature was raised to solvent reflux for 15 min under normal pressure, and the temperature was kept for 20 min after reflux and temperature stabilization, and the mixed monomer composite solution was added dropwise at a constant speed for 3 h. After the dripping was completed, 5 kg of azobisisobutyronitrile and 200 kg of propylene glycol monomethyl ether were added at once, and the temperature was kept for 2 h to obtain an acrylic polymer solution with a solid content of about 55%. The acrylic polymer solution was distilled in the reactor to obtain an acrylic resin concentrated solution with a solid content of about 75%. The acrylic resin concentrated solution was sent to a twin-screw exhaust extruder, and the propylene glycol monomethyl ether and unreacted residues were continuously discharged in sections. The solids obtained by extrusion were discharged and cooled and sent to granulation to obtain rosin-modified acrylic solid resin particles. The performance indicators of the resin particles are shown in Table 1.

[0063] Table 1 Physical indicators of solid acrylic resin

[0064]

[0065] The rosin-modified acrylic solid resin prepared by the process of the present invention has a good wetting and dispersing effect on pigments and has good adhesion to films. The ink made by using the rosin-modified acrylic solid resin has excellent drying properties and printing adaptability, and has extremely low VOC, all below 50ppm, and is environmentally friendly.

[0066] The equipment used in the present invention, such as the reaction kettle, the twin-screw exhaust extruder, the condensation collection device, the granulator, etc., can all be existing technology equipment.

Claims

1. A process for preparing rosin-modified acrylic solid resin, characterized in that: First, a solid phase synthesis method is used to esterify refined rosin and acrylic acid functional monomers in the presence of a catalyst and an inhibitor to obtain a polymerizable rosin functional monomer with a solid content greater than 98%; then a semi-continuous solution polymerization method is used to obtain an acrylic resin solution with a solid content of 30-60%; then vacuum distillation is performed to obtain an acrylic resin concentrated solution with a solid content of more than 60%; then the acrylic resin concentrated solution is continuously extruded to discharge solids, and at the same time, the solvent and unreacted residual polymerizable rosin functional monomers in the acrylic resin concentrated solution are separated, and the discharged solids are granulated to obtain rosin-modified acrylic resin particles with a VOC index of less than 50 ppm.

2. The preparation process of a rosin-modified acrylic solid resin according to claim 1, characterized in that: The method for obtaining the polymerizable rosin functional monomer by the solid phase synthesis method is as follows; (1.1) Take refined rosin and acrylic acid functional monomer according to the mass ratio, 40-70% of refined rosin, 30-60% of acrylic acid functional monomer, and the total mass of refined rosin and acrylic acid functional monomer is 100%; then take 0.5-5% of the mass of refined rosin as catalyst and 0-4% of the mass of acrylic acid functional monomer as inhibitor; (1.2) Put the refined rosin into the reactor, slowly raise the temperature to 150-180°C, add the catalyst and inhibitor after the refined rosin is melted, then uniformly add the acrylic acid functional monomer to the reactor within 1-4 hours, and then react at 180-230°C to obtain a polymerizable rosin functional monomer with a solid content greater than 98%; The semi-continuous solution polymerization method for obtaining an acrylic resin solution with a solid content of 30 to 60% by the semi-continuous solution polymerization method is as follows: (2.1) Adding 1 to 4 times the mass of acrylate monomer to the prepared polymerizable rosin functional monomer to obtain a composite functional body; (2.2) Take the composite functional body and the solvent according to the mass ratio, the composite functional body is 40-60%, the solvent is 40-60%, and the total mass of the composite functional body and the solvent is 100%; then take an initiator of 2-8% of the mass of the composite functional body and a chain transfer agent of 0-4% of the mass of the composite functional body; (2.2) First, take a portion of the solvent, add the composite functional body, a portion of the initiator and the chain transfer agent into the solvent, and stir and mix them thoroughly to obtain a mixed monomer composite solution; (2.4) adding a portion of the solvent into a stirred reactor, raising the temperature to solvent reflux for 10 to 15 minutes under normal pressure, maintaining the temperature for 15 to 30 minutes after reflux and temperature stabilization, and then dripping the mixed monomer composite solution at a uniform rate for 2 to 4 hours; (2.5) After the mixed monomer composite solution is added dropwise, the remaining solvent and initiator are added and the mixture is kept warm for 1 to 2 hours to obtain an acrylic polymer solution with a solid content of 30 to 60%.

3. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The acrylic functional monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl acrylate, and glycidyl methacrylate.

4. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The catalyst is one or more of zinc oxide, zinc chloride, zinc nitrate and zinc acetate.

5. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The polymerization inhibitor is one or two of hydroquinone and anthraquinone.

6. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The solvent is one or more of ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethyl acetate, and butyl acetate.

7. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The initiator is one or more of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy(2-ethyl)hexanoate, tert-butyl peroxyformate, tert-butyl peroxide, tert-butyl hydroperoxide and tert-amyl hydroperoxide.

8. A process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The chain transfer agent is one or more of dodecyl mercaptan, 2-mercaptoethanol, aliphatic mercaptan, and 2,4-diphenyl-4-methyl-1-pentene.

9. The process for preparing a rosin-modified acrylic solid resin according to claim 2, characterized in that: The acrylic acid ester monomer is one or more of methyl methacrylate, butyl acrylate, isooctyl acrylate, acrylic acid, methacrylic acid, styrene, hydroxyethyl acrylate, hydroxypropyl acrylate, butyl methacrylate and vinyl acetate.

10. The process for preparing a rosin-modified acrylic solid resin according to claim 1 or 2, characterized in that: The method of continuously extruding the acrylic resin concentrated solution to discharge the solid matter and separating the solvent and the unreacted residual polymerizable rosin functional monomer in the acrylic resin concentrated solution is achieved by using a twin-screw venting extruder equipped with a two-stage condensation collection device. The twin-screw venting extruder equipped with the two-stage condensation collection device comprises a twin-screw venting extruder (1), a primary condensation collection device and a secondary condensation collection device sequentially arranged along the twin-screw venting extruder; the primary condensation collection device comprises a primary solvent cooler (2) and a primary solvent collector (3); the inlet of the primary solvent cooler is connected to the front section of the barrel of the twin-screw venting extruder through a pipeline. The first-stage condensation collection device comprises a second-stage solvent cooler (5) and a second-stage solvent collector (6); the inlet of the second-stage solvent cooler is connected to the plurality of outlet holes opened in the rear section of the barrel of the twin-screw exhaust extruder through a pipeline; the outlet of the second-stage solvent cooler is connected to the inlet of the second-stage solvent collector through a pipeline; the outlet of the second-stage solvent collector is connected to the discharge pipeline equipped with a second-stage vacuum pump (7); the feed port of the twin-screw exhaust extruder is connected to the reaction kettle (8) through a pipeline.

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