Liquid rosin resin as well as preparation method and application thereof

Abstract

The invention provides liquid rosin resin as well as a preparation method and application thereof, and belongs to the technical field of resin modification. The preparation method of the liquid rosin resin provided by the invention comprises the following steps: S1, melting rosin; s2, enabling the molten rosin prepared in the step S1 to react with a catalyst and polyol to obtain a reaction mixture; s3, dewatering and cooling the reaction mixture prepared in the step S2, adding a post-treatment agent, and continuously reacting to obtain the liquid rosin resin. The invention also provides the liquid rosin resin prepared by the preparation method. The liquid rosin resin prepared by the method provided by the invention is suitable for both an oily system and a water-based system, can be dispersed in a water-based polymer emulsion without additionally adding an emulsifier, and does not flocculate.

Description

Technical Field

[0001] This invention relates to the field of resin modification technology, and in particular to a liquid rosin resin, its preparation method, and its application. Background Technology

[0002] Rosin is a natural resource derived from plants, and its main component is resin acid. In order to expand the application of rosin, it is usually modified. The carboxyl groups and double bonds in rosin can be used for esterification and addition reactions to produce rosin resins with different physicochemical properties.

[0003] Liquid rosin resin is a non-drying, viscous liquid with good low-temperature fluidity and a relatively low glass transition temperature, making it suitable for low-temperature applications or environments with significant temperature differences between day and night or between different regions. Liquid rosin resin is soluble in ethanol, acetone, ethyl acetate, toluene, dichloromethane, and solvent gasoline, and has good compatibility with acrylates, PVC, CR, and other resins and rubbers. It is flammable and non-toxic.

[0004] Liquid rosin resin contains multiple hydroxyl (-OH) and carboxyl (-COOH) groups in its structure, which gives it excellent solubility and adhesion properties. Liquid rosin resin has a wide range of applications. In the coatings industry, it is used as a thickener, anti-settling agent, and leveling agent to improve coating adhesion and film performance. In plastics processing, it can be used as a stabilizer, lubricant, and anti-aging agent to improve the quality and lifespan of plastic products. In rubber products, it is used as a softener and tackifier to improve the physical and chemical properties of rubber.

[0005] Traditional liquid rosin resins require organic solvents (such as toluene and acetone) for dissolution before being used as tackifying resins in solvent-based adhesives, resulting in high VOC content. Alternatively, they can be saponified or emulsified for use in water-based adhesives, but water-based liquid rosin resins (such as emulsion types) suffer from poor water resistance and insufficient adhesion. Currently, there is no research on liquid rosin resins suitable for both oil-based and water-based systems.

[0006] Chinese patent application CN111892885A discloses a liquid rosin tackifying resin and its production method, which is obtained by melting the liquid rosin resin, reacting it with water and a dispersant, and then emulsifying it. The patent application shows that the prepared liquid rosin tackifying resin has good adhesion and dispersibility, does not undergo morphological changes under different environmental temperatures, and has strong adaptability. However, it does not specifically demonstrate its performance in aqueous systems.

[0007] Chinese patent application CN103540265A discloses a method for preparing liquid rosin resin. The method involves: ① melting solid rosin under an inert gas atmosphere, reacting the rosin with a monobasic or dibasic acid in the presence of a catalyst and an antioxidant, at 150-220°C for 3-5 hours; ② adding a liquid polyol dropwise, reacting at 220-285°C for 8-12 hours; ③ evacuating under vacuum for 1-2 hours, cooling, and discharging the material to obtain the liquid rosin resin. The liquid rosin resin prepared by this method exhibits good aging resistance, a low glass transition temperature, and good low-temperature fluidity, enabling industrial-scale production. However, it does not mention whether it is suitable for aqueous systems.

[0008] Therefore, there is an urgent need for a liquid rosin resin that is applicable to both oil-based and water-based systems to meet the growing demand for water-based systems. Summary of the Invention

[0009] In view of this, and considering that the existing technology cannot provide a liquid rosin resin that is universally applicable to both oil-based and water-based systems, the purpose of this invention is to provide a liquid rosin resin that is universally applicable to both oil-based and water-based systems.

[0010] To achieve the above-mentioned objectives, the present invention provides a method for preparing liquid rosin resin, comprising the following steps: S1. Melt the rosin; S2. The molten rosin prepared in step S1 is reacted with a catalyst and a polyol to obtain a reaction mixture; S3. Remove water from the reaction mixture obtained in step S2, cool it down, add a post-treatment agent, and continue the reaction to obtain liquid rosin resin.

[0011] Further, in step S1, the rosin is one or more of the following: wood rosin, resin rosin, hydrogenated rosin, disproportionated rosin, floating oil rosin, polymerized rosin, fumaric acid rosin, acrylic acid rosin, and maleic rosin.

[0012] Furthermore, the resinous rosin includes Masson rosin and wetland rosin.

[0013] Furthermore, the rosin is selected from at least one of fumaric acid rosin, disproportionated rosin, floating oil rosin, horsetail rosin, and wetland rosin.

[0014] Furthermore, in step S1, the melting temperature of rosin is 180℃-200℃, and the rosin melts in a protective gas atmosphere.

[0015] Furthermore, the protective gas is nitrogen.

[0016] Further, in step S2, the weight of the catalyst is 0.01%-0.5% of the weight of the rosin, and the weight of the polyol is 30%-40% of the weight of the rosin.

[0017] Furthermore, in step S2, the weight of the catalyst is 0.1%-0.5% of the weight of the rosin.

[0018] Furthermore, in step S2, the reaction temperature is 260℃-290℃, and the reaction time is 6-15 hours.

[0019] Furthermore, in step S2, the heating rate to the reaction temperature is 5-15℃ / h.

[0020] Furthermore, in step S2, the heating rate to the reaction temperature is 10°C / h.

[0021] Further, in step S2, the polyol is one or more of ethylene glycol, polyethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, glycerol, trimethylolpropane, 1,2,4-butanetriol, sorbitol, mannitol, and pentaerythritol.

[0022] Furthermore, in step S2, the polyol is one or more of glycerol, polyethylene glycol, diethylene glycol, and triethylene glycol.

[0023] Furthermore, in step S2, the polyol is one or more of polyethylene glycol, diethylene glycol, and triethylene glycol.

[0024] In one specific embodiment of the present invention, the polyol is polyethylene glycol, triethylene glycol, diethylene glycol, or propylene glycol.

[0025] Further, in step S2, the catalyst is one or more of the following: thiophenols, hypophosphorous acid, hypophosphite, acetate, phosphorous acid, phosphite, alkali metals, alkaline earth metals, and metal oxides.

[0026] In one specific embodiment of the present invention, the catalyst is calcium acetate, zinc oxide, calcium hypophosphite, or calcium phosphite.

[0027] Furthermore, in step S3, the water removal is specifically carried out by vacuuming.

[0028] Furthermore, in step S3, the vacuuming time is 0.5-2 hours.

[0029] Furthermore, in step S3, the vacuuming time is 1 hour.

[0030] Furthermore, in step S3, the cooling specifically refers to cooling to 100℃-150℃, and continuing the reaction for 1-3 hours.

[0031] Further, in step S3, the mass of the post-treatment agent is 0.1%-0.5% of the rosin mass.

[0032] Further, in step S3, the post-treatment agent is one or more of citric acid, tartaric acid, malic acid, oxalic acid, phosphoric acid, and pyrophosphate.

[0033] Furthermore, in step S3, the post-treatment agent is one or more of citric acid, malic acid, and oxalic acid.

[0034] In one specific embodiment of the present invention, the post-treatment agent is malic acid, oxalic acid, or citric acid.

[0035] In a second aspect, the present invention provides a liquid rosin resin, which is prepared by any of the preparation methods described above.

[0036] Thirdly, the present invention provides the use of liquid rosin resin prepared according to the preparation method or the use of said liquid rosin resin in the preparation of floor adhesives, low-temperature resistant hot melt adhesives, and water-based box adhesives.

[0037] Compared with the prior art, the present invention has the following beneficial effects: (1) The liquid rosin resin molecular chain of the present invention contains both oleophilic rosin backbone and hydrophilic polyether segment, and therefore can be applied to both oily and watery systems.

[0038] (2) Compared with the liquid rosin tackifying resin disclosed in the prior art such as CN111892885A, it can be dispersed in aqueous polymer emulsion without the need for additional emulsifiers and does not flocculate; it can still maintain good viscosity stability after 30 days.

[0039] (3) The PVC flooring adhesive produced from the acrylate emulsion system using the liquid rosin resin prepared by the method of the present invention is uniform and free of flocculation. The initial tack strength tested according to GB / T 4852-2002 standard is 8-11 ball rolling strength, and the peel strength tested according to GB / T 2792 standard is 4.6-6.4 N / cm. The storage stability is greater than 6 months. This indicates that the liquid rosin resin prepared according to the method of the present invention can be well applied in acrylate emulsion systems. Detailed Implementation

[0040] Terminology and Declarations of this Invention: 1. Articles “a,” “a kind,” and “the”: These include plural objects unless otherwise explicitly specified as a single (kind) object.

[0041] 2. Numerical Range: Unless otherwise expressly stated, all ranges or ratios disclosed herein shall be construed as including any and all subranges or subratios contained herein. For example, a stated range or ratio of 1 to 30 shall be considered to be included between the minimum value of 1 and the maximum value of 30, and includes any subranges or subratios, integers, decimals, or subranges or subratios consisting of integers or decimals, including endpoints.

[0042] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0043] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0044] In the following examples, some of the reagents were sourced from the following table: Table 1

[0045] Basic Implementation I. Preparation of fumarate rosin (1) Put rosin into the reactor and heat it to 180℃-200℃ to melt it under the protection of inert gas; (2) Add 1-10% fumaric acid by weight of rosin and react at 195℃-210℃ for 0.5-3 hours. The product is fumaric acid rosin.

[0046] II. Preparation of Acrylic Rosin (1) Put rosin into the reactor and heat it to 180℃-200℃ to melt it under the protection of inert gas; (2) Slowly add 1-10% of the weight of rosin with acrylic acid, react at 210℃-230℃ for 0.5-3 hours, and the acrylic rosin is obtained by discharge.

[0047] III. Preparation of Malaysian Rosin (1) Put rosin into the reactor and heat it to 160℃-180℃ to melt it under the protection of inert gas; (2) Add 1-10% of maleic anhydride by weight of rosin and react at 190℃-200℃ for 0.5-3 hours. Maleic rosin is obtained by discharging the product.

[0048] The above three types of rosin are all prepared using conventional methods. Those skilled in the art can make conventional adjustments according to specific experimental conditions to obtain the desired products.

[0049] Example 1 S1. Add 500g of wet rosin to a reaction flask equipped with a thermometer and a stirrer, and heat it to 200℃ under nitrogen protection to melt it. S2. Add 1.5 g of calcium acetate catalyst and 185 g of triethylene glycol, heat to 265 °C at a rate of 10 °C / h, and stir the reaction at 265 °C for 10 hours. S3. Vacuum for 1 hour to remove the water generated in the reaction, cool to 130°C, add 1.5 g of oxalic acid as a post-treatment agent, and then stir and react at 130°C for 3 hours. The liquid rosin resin is then discharged.

[0050] Example 2 S1. Add 500 grams of rosin to a reaction flask equipped with a thermometer and a stirrer, and heat it to 190°C under nitrogen protection to melt it. S2. Add 0.5 g of zinc oxide catalyst and 200 g of polyethylene glycol 200, heat to 275 °C at a rate of 10 °C / h, and stir the reaction at 275 °C for 7 hours. S3. Vacuum for 1 hour to remove the water generated in the reaction, cool to 150℃, add 1.5g of malic acid as a post-treatment agent, and then stir and react at 150℃ for 1 hour. The liquid rosin resin is then discharged.

[0051] Example 3 S1. Add 500g of fumaric rosin to a reaction flask equipped with a thermometer and a stirrer, and heat to 180℃ under nitrogen protection to melt it. S2. Add 2.5 g of calcium hypophosphite catalyst and 200 g of diethylene glycol, heat to 290 °C at a rate of 5 °C / h, and stir the reaction at 290 °C for 6 hours. S3. Vacuum for 0.5 hours to remove the water generated in the reaction, cool to 100℃, add 2.5g of citric acid as a post-treatment agent, and then stir and react at 100℃ for 2 hours. The liquid rosin resin is then discharged.

[0052] Example 4 S1. Add 500g of disproportionated rosin to a reaction flask equipped with a thermometer and a stirrer, and heat it to 200℃ under nitrogen protection to melt it. S2. Add 0.05 g of calcium phosphite catalyst and 185 g of propylene glycol, heat to 260 °C at a rate of 15 °C / h, and stir the reaction at 260 °C for 15 hours. S3. Vacuum for 2 hours to remove the water generated in the reaction, cool to 130℃, add 0.5g of citric acid as a post-treatment agent, and then stir and react at 130℃ for 3 hours. The liquid rosin resin is then discharged.

[0053] Example 5 S1. Add 500g of floating rosin to a reaction flask equipped with a thermometer and a stirrer, and heat to 200℃ under nitrogen protection to melt it. S2. Add 1.5 g of calcium acetate catalyst, 15 g of glycerol and 150 g of triethylene glycol, heat to 280 °C at a rate of 10 °C / h, and stir at 280 °C for 10 hours. S3. Vacuum for 1 hour to remove the water generated in the reaction, cool to 130°C, add 1.5 g of oxalic acid as a post-treatment agent, and then stir and react at 130°C for 3 hours. The liquid rosin resin is then discharged.

[0054] Comparative Example 1 The difference from Example 1 is that no post-treatment agent was added in step S3, but the rest are the same.

[0055] Comparative Example 2 Liquid rosin resin prepared according to Example 1 of Chinese patent application publication number CN103540265A.

[0056] Comparative Example 3 The difference from Example 1 is that the reaction temperature in step S2 is 300°C, while the rest are the same.

[0057] Comparative Example 4 The difference from Example 1 is that the amount of triethylene glycol in step S2 is 210g, while the rest are the same.

[0058] Comparative Example 5 The difference from Example 1 is that oxalic acid in step S3 is replaced with succinic acid, while the rest are the same.

[0059] The properties of the liquid rosin resins prepared in Examples 1-5 and Comparative Examples 1-5 are shown in Table 2.

[0060] Table 2

[0061] Effect test case 1. The dispersibility of resin in emulsion Adjust the speed of the high-speed disperser to 500 rpm, add 100 g of acrylate emulsion to the dispersion vessel, and then add 5 g of the liquid resin prepared in Examples 1-6 and Comparative Examples 1-5 respectively, and disperse for 30 min; observe the stability after standing; test the change in emulsion viscosity after 30 days.

[0062] 2. Solubility of resin in toluene Add 15g of toluene to a stoppered conical flask, and then add 15g of the liquid resin prepared in Examples 1-6 and Comparative Examples 1-5 respectively. Dissolve the resin by shaking in a water bath at 25°C for 30 minutes, and observe the resin dissolution.

[0063] The dispersibility of liquid rosin resin in emulsion and its solubility in toluene are shown in Table 3 below.

[0064] Table 3

[0065] As shown in Table 3, the liquid rosin resin prepared by this invention can be directly dispersed in aqueous acrylate emulsions without the addition of emulsifiers, exhibits no flocculation, and demonstrates good viscosity stability. Furthermore, the liquid rosin resin prepared by this invention also shows good solubility in the oily solvent toluene. Therefore, the liquid rosin resin prepared by this invention can be used in oily adhesive systems and can also be stably dispersed in aqueous adhesive systems such as polymer emulsions.

[0066] 3. Performance of PVC flooring adhesive Adjust the speed of the high-speed disperser to 500 rpm, and add 100g of acrylic emulsion, 10g of liquid resin prepared in Examples 1-5 and Comparative Examples 1-5, talc powder, mica powder, dispersant, defoamer and thickener to the dispersion vessel according to the weight ratio shown in Table 4. Disperse for 30 minutes to obtain PVC floor adhesive.

[0067] Table 4

[0068] After standing, observe the appearance of the PVC flooring adhesive. Stir with a glass rod and lift it to observe the fluidity and presence of flocculation. Rolling ball tack: Apply the PVC flooring adhesive evenly to a PET film and test using the inclined plane rolling ball method in GB / T 4852-2002. Peel strength: Test the peel strength between the PVC flooring adhesive and the substrate according to GB / T 2792. Storage stability: Store the PVC flooring adhesive in a sealed brown bottle at room temperature, observe and measure the viscosity periodically. Storage stability is defined as a viscosity change not exceeding 10%, no surface skinning, and no flocculation. The properties of the prepared PVC flooring adhesive are shown in Table 5 below.

[0069] Table 5

[0070] Table 2 shows that the liquid rosin resins of Examples 1-5 exhibited relatively uniform color, acidity, hydroxyl value, and viscosity, while the comparative examples showed greater variation. For instance, the liquid rosin resin of Comparative Example 2 had a viscosity of 60,500 mPa·s at 50°C, and the liquid rosin resin of Comparative Example 4 had a hydroxyl value of 109, both of which were less than ideal. Table 3 shows that the liquid rosin resins of Examples 1-5 exhibited good dispersibility in emulsions with no flocculation, good solubility in toluene, and viscosity stability of Δη≤5% within 30 days. In contrast, the liquid rosin resins of Comparative Examples 1-5 showed poor dispersibility, widespread flocculation and stratification, and inferior solubility and viscosity stability in toluene compared to the samples of Examples 1-5. After preparing the above samples into floor adhesives, testing revealed that floor adhesives 1-5 had a uniform and stable appearance, were free of flocculation, had good initial tack and peel strength, and exhibited storage stability greater than 6 months. Floor adhesive samples 6-10, however, were significantly inferior to floor adhesive samples 1-5 in both appearance and storage stability. As shown in Table 5, the PVC flooring adhesive prepared by adding the liquid rosin resin of this invention exhibits good storage stability and can improve the initial tack and peel strength of the PVC flooring adhesive. This indicates that the liquid rosin resin prepared according to the method of this invention can be well applied in acrylic emulsion systems.

[0071] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing liquid rosin resin, characterized in that, Includes the following steps: S1. Melt the rosin; S2. The molten rosin prepared in step S1 is reacted with a catalyst and a polyol to obtain a reaction mixture; S3. Remove water from the reaction mixture obtained in step S2, cool it down, add a post-treatment agent, and continue the reaction to obtain liquid rosin resin.

2. The preparation method according to claim 1, characterized in that, In step S1, the rosin is one or more of the following: wood rosin, resin rosin, hydrogenated rosin, disproportionated rosin, floating oil rosin, polymerized rosin, fumaric acid rosin, acrylic acid rosin, and maleic rosin.

3. The preparation method according to claim 1, characterized in that, In step S2, the weight of the catalyst is 0.01%-0.5% of the weight of the rosin, preferably 0.1%-0.5%; and the weight of the polyol is 30%-40% of the weight of the rosin.

4. The preparation method according to claim 1, characterized in that, In step S2, the reaction temperature is 260℃-290℃, the heating rate to the reaction temperature is 5-15℃ / h, and the reaction time is 6-15 hours.

5. The preparation method according to claim 4, characterized in that, In step S2, the heating rate to the reaction temperature is 10℃ / h.

6. The preparation method according to claim 1, characterized in that, In step S2, the polyol is one or more of ethylene glycol, polyethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,4-butanediol, glycerol, trimethylolpropane, 1,2,4-butanetriol, sorbitol, mannitol, and pentaerythritol.

7. The preparation method according to claim 1, characterized in that, In step S2, the catalyst is one or more of the following: thiophenols, hypophosphorous acid, hypophosphite, acetate, phosphorous acid, phosphite, alkali metals, alkaline earth metals, and metal oxides.

8. The preparation method according to claim 1, characterized in that, In step S3, the cooling process specifically involves cooling to 100℃-150℃; the reaction continues for 1-3 hours; the mass of the post-treatment agent is 0.1%-0.5% of the rosin mass, and the post-treatment agent is one or more of citric acid, tartaric acid, malic acid, oxalic acid, phosphoric acid, and pyrophosphate.

9. A liquid rosin resin, prepared by the preparation method according to any one of claims 1-8.

10. The use of the liquid rosin resin prepared by the preparation method according to any one of claims 1-8 or the liquid rosin resin according to claim 9 in the preparation of floor adhesives, low-temperature resistant hot melt adhesives, and water-based box adhesives.

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