Highly dispersed composite resorcinol mother granules and a method for preparing the same

Abstract

The application provides a high-dispersion composite resorcinol master batch and a preparation method thereof, relates to the technical field of rubber additives, and comprises the following components in parts by weight: resorcinol 70-85 parts; composite rubber carrier 8-15 parts; modified nano-silicon dioxide 0.5-5 parts; polylactic acid microspheres 1-3 parts; modified zinc fatty acid soap 1-3 parts; antioxidant 0-2 parts; white carbon black 0-3 parts. The application significantly improves the compatibility with resorcinol through the synergistic effect of the composite rubber carrier; the sublimation and dispersion of resorcinol in the high-temperature processing process are effectively inhibited by introducing the surface-modified nano-silicon dioxide and the modified zinc fatty acid soap system; the uniform dispersion and controllable release of resorcinol in the mixing process are realized by using the porous polylactic acid microspheres through physical coating; and a stable three-dimensional coating network is formed by combining the three-section gradient temperature control internal mixing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rubber additives, in particular to a high-dispersion composite resorcinol masterbatch and a preparation method thereof. BACKGROUND

[0002] As an important adhesive in the rubber industry, resorcinol is widely used in tire, hose, belt and other products. It forms a crosslinked network by reacting with methylene donors, significantly improving the adhesion performance of rubber and skeleton materials. However, there are obvious defects in the direct use of traditional resorcinol: its sublimation property leads to the generation of irritating smoke during the mixing process, causing harm to the production environment and workers' health; at the same time, resorcinol is easily oxidized and discolored at high temperature, and is prone to moisture absorption and caking during storage, which leads to decreased activity and uneven dispersion, directly affecting the process stability of the rubber compound and the performance of the final product.

[0003] Invention disclosure No. CN117487104A discloses a preparation method of resorcinol-formaldehyde resin for enhancing the adhesion of skeleton-rubber. This scheme uses styrene-butadiene rubber as a carrier, physically coats resorcinol, and adds stearic acid, naphthenic oil and other additives to prepare a masterbatch, which can reduce dust flying and processing smoke to some extent. However, the masterbatch prepared by this scheme still has the defects of low dispersion efficiency and insufficient high-temperature stability: the compatibility of the rubber carrier and resorcinol is limited, which makes it difficult for the masterbatch to disperse uniformly during the mixing process, and resorcinol may still escape from the carrier at high temperature, causing local concentration to be too high or volatile loss.

[0004] Invention disclosure No. CN102875754A discloses a modified resorcinol-formaldehyde resin, its preparation method and rubber composition. This scheme uses resorcinol-formaldehyde resin to reduce the content of free resorcinol and reduce processing smoke, but the increase in molecular weight increases the Mooney viscosity of the rubber compound, and the strong hygroscopicity of the resin easily causes problems such as rubber scorching or interface delamination.

[0005] Invention disclosure No. CN114671741A discloses a resorcinol oligomer derivative for rubber tires and its masterbatch preparation and application. By introducing unsaturated hydrocarbons such as styrene to chemically modify resorcinol, the stability of the rubber can be improved, but the presence of side groups exacerbates the hysteresis heat of the rubber compound, affecting the durability in dynamic use scenarios such as tires. SUMMARY

[0006] In view of the problems of uneven dispersion and easy volatilization at high temperature of the existing resorcinol, the application provides a high-dispersion composite resorcinol masterbatch and a preparation method thereof. The masterbatch significantly improves the compatibility with resorcinol through the synergistic effect of the composite rubber carrier; the introduction of surface-modified nano-silicon dioxide directionally anchors the resorcinol molecules, and cooperates with the modified zinc soap of fatty acid with dynamic crosslinking characteristics to effectively inhibit the sublimation and dispersion of resorcinol in the high-temperature processing process; the porous polylactic acid microspheres are used as the loading unit of resorcinol, and the uniform dispersion and controllable release of resorcinol in the mixing process are realized through physical coating, and the dispersion efficiency of the active ingredient in the masterbatch is further improved; and the three-stage gradient temperature control internal mixing process is combined to complete the in-situ curing of the masterbatch structure while optimizing the dispersion effect, and a stable three-dimensional coating network is formed.

[0007] To achieve the above object, the technical scheme provided by the application is as follows:

[0008] A high-dispersion composite resorcinol masterbatch comprises the following components by weight:

[0009] Resorcinol 70-85 parts; composite rubber carrier 8-15 parts; modified nano-silicon dioxide 0.5-5 parts; polylactic acid microspheres 1-3 parts; modified zinc soap of fatty acid 1-3 parts; antioxidant 0-2 parts; white carbon black 0-3 parts.

[0010] As preferred, the composite rubber carrier is composed of liquid rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber at a mass ratio of 6:4:1. The polar molecular chain segments of the styrene-butadiene rubber and the flexible molecular chain segments of the ethylene-propylene-diene rubber form an interpenetrating network structure at the molecular chain level through the excellent physical phase fusion and chemical phase solubility of the liquid natural rubber, and then the mechanical kneading and blending of the internal mixer, which enhances the physical adsorption capacity of the carrier to resorcinol at the nanoscale, and constructs a gradient coating barrier at the micrometer scale, thereby significantly inhibiting the dispersion of resorcinol in the high-temperature stage of internal mixing.

[0011] More preferably, the liquid rubber is one or more of liquid reclaimed rubber, liquid natural rubber, liquid styrene-butadiene rubber, liquid polyisoprene rubber or liquid cis-butadiene rubber. The liquid rubber has dual functions of dispersion carrier and softening agent, and its low viscosity characteristics reduce the interfacial energy of the rubber matrix through in-situ wetting effect, so that the bonding strength of the masterbatch and the rubber matrix is improved, and the phase separation phenomenon in the processing process is completely eliminated.

[0012] As preferred, the modified nano-silicon dioxide is modified by silane coupling agent KH-550 and has a particle size of 10-50 nm. The surface silane groups directionally adsorb resorcinol molecules through the anchoring effect, and reduce the particle aggregation tendency, and the high specific surface area of the nanoparticles forms physical crosslinking points with the rubber carrier, thereby further improving the dispersion uniformity of the masterbatch and the dynamic mechanical properties of the rubber compound.

[0013] Preferably, the porosity of the polylactic acid microspheres is 30-50%, and the particle size is 50-200 μm. The porous structure of the polylactic acid microspheres can achieve efficient loading and gradient release of resorcinol. In the initial stage of mixing, the pores on the surface of the microspheres are preferentially opened, promoting the rapid dispersion of resorcinol. As the temperature rises, the internal pores gradually release the residual components, avoiding local supersaturation and volatile loss caused by concentrated release in the initial stage of processing.

[0014] Preferably, the modified zinc fatty acid soap is prepared by mixing C8-C22 unsaturated fatty acid and saturated fatty acid at a mass ratio of 2:1-3:1, then reacting with a zinc compound, and then blending and modifying with a reversible crosslinking modifier. The flexible segment of the unsaturated fatty acid and the rigid structure of the saturated fatty acid synergistically regulate the polarity of the zinc soap, enhancing its compatibility with the rubber carrier. The reversible crosslinking network dynamically dissociates at the processing temperature, reducing the migration resistance of the zinc soap, and then re-crosslinks after cooling to form a stable physical barrier to block the sublimation path of resorcinol.

[0015] More preferably, the unsaturated fatty acid is one or more of oleic acid or palmitoleic acid; the saturated fatty acid is one or more of stearic acid or lauric acid; the zinc compound is one or more of zinc oxide or zinc hydroxide; and the reversible crosslinking modifier is one or more of furan-maleimide derivative or furan methylamine grafted zinc ricinoleate. The unsaturated double bond of oleic acid or palmitoleic acid provides a dynamic crosslinking site, and the reversible reaction with the furan group forms a temperature-responsive network, allowing the zinc soap to flow moderately at high mixing temperatures to optimize dispersion and achieve dual stability in processing and use scenarios.

[0016] The application also provides a preparation method of high-dispersion composite resorcinol pellets, comprising the following steps:

[0017] (1) Resorcinol is added to deionized water and stirred to form a premix, and polylactic acid microspheres are added to the premix and ultrasonically dispersed to form a pre-mixed solution. The pre-mixed solution is subjected to spray drying to obtain a pre-mixed material;

[0018] (2) The remaining raw materials are added to a mixing machine in proportion, and the mixing temperature is controlled in stages to obtain a rubber compound;

[0019] (3) The rubber compound is extruded through a seven-section temperature-controlled twin-screw extruder, cut into particles, and then cooled to room temperature to obtain high-dispersion composite resorcinol pellets.

[0020] As preferred, the stirring mixing temperature in the step (1) is 60-80 DEG C, and the stirring time is 20-30 min; the ultrasonic dispersion time is 15-25 min. The mild heating accelerates the dissolution and diffusion of resorcinol in deionized water, while avoiding the collapse of the pores of the polylactic acid microspheres caused by high temperature; the precise time window of ultrasonic dispersion ensures that the pores on the surface and inside of the microspheres are fully loaded with resorcinol, forming a homogeneous premix system, which lays a foundation for the subsequent gradient release in the mixing stage.

[0021] As preferred, in the step (2), the first section of the mixing temperature is 60-70 DEG C, the mixing time is 5-10 min, the second section is heated to 70-90 DEG C, and the mixing time is 8-10 min, and the third section is cooled to 50-70 DEG C after adding the premix, and the mixing time is 10-15 min. The first section of low temperature mixing: preliminary activation of the dynamic molecular interpenetrating network of the composite rubber carrier, promoting the uniform dispersion of modified nano-silica and zinc soap of fatty acid, avoiding the early escape of resorcinol at high temperature; the second section of temperature mixing: through the shearing heat of the surface silane group anchoring effect of nano-silica, the directional adsorption of resorcinol is strengthened, and the reversible network of modified zinc soap is gradually dissociated to release the flowability to optimize the dispersion interface; the third section of temperature mixing: the premix under low temperature conditions promotes the selective opening of the pores on the surface of the polylactic acid microspheres, realizes the controlled release of resorcinol, and the reversible crosslinking network is reformed, solidifying the internal coating structure of the master batch, inhibiting the volatilization risk in the subsequent processing.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) Through the synergistic design of the composite rubber carrier, liquid rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber are compounded in proportion to enhance the compatibility with resorcinol, and avoid uneven dispersion caused by the polarity difference of the carrier during mixing; and through the slow-release technology of high-porosity polylactic acid microspheres, the gradual release of resorcinol is realized at high temperature in the mixing, avoiding the excessive local concentration of resorcinol, and further enhancing the dispersibility of the effective components;

[0024] (2) Through the directional adsorption of modified nano-silica by silane coupling agent, the resorcinol molecules are fixed by hydrogen bond and physical adsorption to inhibit the migration and escape of the effective components; and through the reversible crosslinking modification of the zinc soap network of fatty acid, combined with the optimization of the segmented mixing process, a dynamic crosslinking network is formed around the resorcinol at the processing temperature to limit its free migration, and after cooling, the network is reformed, significantly reducing the loss of volatilization at high temperature;

[0025] (3) Through the synergistic lubrication and anti-hygroscopicity composite design of liquid rubber, the viscosity and mooney stability of the rubber compound are balanced, and the synergistic effect of the hydrophobic pores of the polylactic acid microspheres and the hydrophobic surface of the modified zinc soap of fatty acid is utilized to reduce the risk of moisture absorption and caking of the master batch. DETAILED DESCRIPTION

[0026] The application will be further described in connection with the specific embodiments.

[0027] Example 1

[0028] The embodiment provides a general high-dispersion composite resorcinol masterbatch formula, and specifically comprises the following components in parts by weight:

[0029] Resorcinol 70-85 parts; composite rubber carrier 8-15 parts; modified nano-silicon dioxide 0.5-5 parts; polylactic acid microspheres 1-3 parts; modified zinc fatty acid soap 1-3 parts; antioxidant 0-2 parts; white carbon black 0-3 parts.

[0030] In some preferred embodiments, the composite rubber carrier is composed of liquid rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber at a mass ratio of 6:4:1. The technical effect is that the polar molecular chain segments of the styrene-butadiene rubber and the flexible molecular chain segments of the amorphous region of the ethylene-propylene-diene rubber form an interpenetrating network structure at the molecular chain level through the excellent physical phase compatibility and chemical phase solubility of the liquid natural rubber, and the mechanical kneading and blending of the internal mixer, thereby enhancing the physical adsorption capacity of the carrier to resorcinol at the nanoscale and constructing a gradient coating barrier at the micrometer scale, and significantly inhibiting the escape of resorcinol during the high-temperature stage of the internal mixer.

[0031] In some more preferred embodiments, the liquid rubber is one or more of liquid reclaimed rubber, liquid natural rubber, liquid styrene-butadiene rubber, liquid polyisoprene rubber or liquid cis-butadiene rubber. The liquid rubber has dual functions of dispersing carrier and softening agent, and its low viscosity characteristics reduce the rubber matrix interfacial energy through in-situ wetting effect, so that the bonding strength of the masterbatch and the rubber matrix is improved, and the phase separation phenomenon in the processing process is completely eliminated.

[0032] In some preferred embodiments, the modified nano-silicon dioxide is modified by silane coupling agent KH-550, and the particle size is 10-50 nm. The technical effect is that the resorcinol molecules are adsorbed in a directional manner through the anchoring effect of the surface silane groups, and the particle aggregation tendency is reduced, and the high specific surface area of the nanoparticles forms physical crosslinking points with the rubber carrier, thereby further improving the dispersion uniformity of the masterbatch and the dynamic mechanical properties of the rubber compound.

[0033] In some preferred embodiments, the polylactic acid microspheres have a porosity of 30-50% and a particle size of 50-200 μm. The technical effect is that the porous structure of the polylactic acid microspheres can achieve efficient loading and gradient release of resorcinol, the surface pores of the microspheres are preferentially opened in the initial stage of the internal mixer, and the dispersion of resorcinol is promoted; as the temperature rises, the internal pores gradually release the residual components, thereby avoiding local supersaturation and volatilization loss caused by concentrated release in the initial stage of processing.

[0034] In some preferred embodiments, the modified zinc fatty acid soap is prepared by mixing C8-C22 unsaturated fatty acid and saturated fatty acid at a mass ratio of 2:1-3:1, then reacting with zinc compound, and then blending with reversible crosslinking modifier. The technical effect is that the flexible segment of unsaturated fatty acid and the rigid structure of saturated fatty acid synergistically regulate the polarity of zinc soap, enhancing its compatibility with the rubber carrier; the reversible crosslinking network dynamically dissociates at the processing temperature, reducing the migration resistance of zinc soap, and then re-crosslinks after cooling to form a stable physical barrier to block the sublimation of resorcinol.

[0035] In some more preferred embodiments, the unsaturated fatty acid is one or more of oleic acid or palmitoleic acid; the saturated fatty acid is one or more of stearic acid or lauric acid; the zinc compound is one or more of zinc oxide or zinc hydroxide; and the reversible crosslinking modifier is one or more of furan-maleimide derivative or furan methylamine grafted zinc ricinoleate. The technical effect is that the unsaturated double bond of oleic acid or palmitoleic acid provides a dynamic crosslinking site, and the reversible reaction with furan group forms a temperature-responsive network, allowing the zinc soap to flow moderately at high temperature in the internal mixer to optimize dispersion, achieving dual stability in processing and use scenarios.

[0036] The present embodiment also provides a preparation method of the overall high-dispersion composite resorcinol masterbatch, specifically comprising the following steps:

[0037] (1) stirring and mixing resorcinol in deionized water, adding polylactic acid microspheres for ultrasonic dispersion to form a premix, and then spray drying the premix to obtain a premix;

[0038] (2) adding the remaining raw materials into an internal mixer in proportion, and controlling the internal mixing temperature in stages to obtain a rubber compound;

[0039] (3) extruding the rubber compound through a seven-stage temperature control extruder, cutting and cooling to room temperature to obtain the high-dispersion composite resorcinol masterbatch.

[0040] In some preferred embodiments, the stirring and mixing temperature in step (1) is 60-80°C, and the stirring time is 20-30 min; and the ultrasonic dispersion time is 15-25 min. The technical effect is that mild heating accelerates the dissolution and diffusion of resorcinol in deionized water, while avoiding excessive temperature to cause the collapse of polylactic acid microsphere pores; and the precise time window of ultrasonic dispersion ensures that the microsphere surface and internal pores are fully loaded with resorcinol, forming a homogeneous premix system and laying a foundation for gradient release in the subsequent internal mixing stage.

[0041] In some preferred embodiments, the first section of the mixing temperature in step (2) is 60-70℃, the mixing time is 5-10 min, the second section is heated to 70-90℃, and the mixing time is 8-10 min, and the third section is cooled to 50-70℃ after adding the premix, and the mixing time is 10-15 min. The technical effect is that the first section of low temperature mixing: preliminarily activates the dynamic molecular interpenetrating network of the composite rubber carrier, promotes the uniform dispersion of the modified nano-silica and zinc soap of fatty acid, and avoids the premature escape of resorcinol at high temperature; the second section of heating mixing: excites the surface silane group anchoring effect of nano-silica through shearing heat, strengthens the directional adsorption of resorcinol, and gradually dissociates the reversible network of modified zinc soap to release the flowability to optimize the dispersion interface; the third section of cooling mixing: the premix promotes the selective opening of the surface pores of the polylactic acid microspheres under low temperature conditions, realizes the controlled release of resorcinol, and the reversible crosslinked network is reformed to solidify the internal coating structure of the master batch, thereby inhibiting the volatilization risk in subsequent processing.

[0042] Example 2

[0043] The embodiment provides a high-dispersion composite resorcinol master batch, which specifically comprises the following components by weight:

[0044] Resorcinol 75 parts, composite rubber carrier 10 parts, KH-550 modified nano-silica 3 parts, polylactic acid microspheres 2 parts, modified zinc soap of fatty acid 2 parts, antioxidant 1 part, and white carbon black 2 parts.

[0045] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber at a mass ratio of 6:4:1; the modified zinc soap of fatty acid is obtained by reacting zinc oxide with a mixture of oleic acid and stearic acid at a mass ratio of 2:1, and then blending and modifying the obtained product with furan-maleimide derivative; and the antioxidant is antioxidant 1010.

[0046] The embodiment also provides a preparation method of the high-dispersion composite resorcinol master batch, which specifically comprises the following steps:

[0047] (1) Premix dispersion: resorcinol is added to deionized water in proportion, stirred and mixed at 70℃ for 20 min, polylactic acid microspheres are ultrasonically dispersed for 20 min to form a premix, and the premix is subjected to spray drying to obtain a premix;

[0048] (2) Stepwise mixing: the remaining raw materials are added to a mixer in proportion, and the mixing temperature is controlled in sections, the first section of the mixing temperature is 60℃, the mixing time is 10 min, the second section is heated to 90℃, the mixing time is 10 min, and the third section is cooled to 70℃ after adding the premix, and the mixing time is 10 min to obtain a rubber compound;

[0049] (3) Extrusion granulation: the rubber material is extruded by a seven-section temperature control extruder, the temperature is 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃, 80-70℃ respectively, and then cooled to room temperature after granulation to obtain high dispersion type composite resorcinol granules.

[0050] Example 3

[0051] The embodiment provides a high dispersion type composite resorcinol granule, and specifically comprises the following components by weight:

[0052] Resorcinol 75 parts; composite rubber carrier 15 parts; KH-550 modified nano silicon dioxide 2 parts; polylactic acid microspheres 2 parts; modified zinc fatty acid soap 2 parts; antioxidant 1 part; white carbon black 2 parts.

[0053] The composite rubber carrier is composed of liquid reclaimed rubber, styrene butadiene rubber and ethylene propylene terpolymer at a mass ratio of 6:4:1; the modified zinc fatty acid soap is obtained by mixing oleic acid and stearic acid at a mass ratio of 3:1 and then reacting with zinc oxide, and then blending modification by furan-maleimide derivative; the antioxidant is antioxidant 1010.

[0054] The embodiment also provides a preparation method of the high dispersion type composite resorcinol granule, and specifically comprises the following steps:

[0055] (1) Pre-mixing and dispersing: resorcinol is added to deionized water in proportion, stirred and mixed at 70℃ for 20min, polylactic acid microspheres are added and ultrasonically dispersed for 20min to form a pre-mixing liquid, and the pre-mixing liquid is subjected to spray drying to obtain a pre-mixing material;

[0056] (2) Sectional mixing: the remaining raw materials are added to a mixing mill in proportion, and the mixing temperature is controlled in sections, the first section is 60℃, the mixing time is 10min, the second section is heated to 90℃, the mixing time is 10min, and the third section is cooled to 70℃ after adding the pre-mixing material, and the mixing time is 10min to obtain a rubber material;

[0057] (3) Extrusion granulation: the rubber material is extruded by a seven-section temperature control extruder, the temperature is 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃, 80-70℃ respectively, and then cooled to room temperature after granulation to obtain high dispersion type composite resorcinol granules.

[0058] Example 4

[0059] The embodiment provides a high dispersion type composite resorcinol granule, and specifically comprises the following components by weight:

[0060] Resorcinol 85 parts; composite rubber carrier 15 parts; KH-550 modified nano-silica 2 parts; polylactic acid microspheres 2 parts; modified zinc fatty acid soap 2 parts; antioxidant 1 part; white carbon black 2 parts.

[0061] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber in a mass ratio of 6:4:1; the modified zinc fatty acid soap is obtained by mixing oleic acid and stearic acid in a mass ratio of 3:1, then reacting with zinc oxide, and then modifying the obtained product with furan-maleimide derivative; and the antioxidant is antioxidant 1010.

[0062] The embodiment also provides a preparation method of the high-dispersion composite resorcinol granules, specifically including the following steps:

[0063] (1) Pre-mixing and dispersing: resorcinol is added into deionized water in proportion, stirred and mixed at 70℃ for 20 min, polylactic acid microspheres are ultrasonically dispersed for 20 min to form a pre-mixing solution, and the pre-mixing solution is subjected to spray drying to obtain a pre-mixing material;

[0064] (2) Subsection banburying: the remaining raw materials are added into a banburying machine in proportion, the banburying temperature is controlled in subsection, the banburying temperature is 60℃ in the first section, the mixing time is 10 min, the temperature is increased to 90℃ in the second section, the mixing time is 10 min, the temperature is decreased to 70℃ in the third section after the pre-mixing material is added, and the mixing time is 10 min to obtain a rubber compound;

[0065] (3) Extruding and granulating: the rubber compound is extruded by a double-screw extruder in seven sections with the temperature being 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃ and 80-70℃ respectively, and then cooled to room temperature after being cut into particles to obtain the high-dispersion composite resorcinol granules.

[0066] Example 5

[0067] The embodiment provides a high-dispersion composite resorcinol granule, specifically including the following components by weight:

[0068] Resorcinol 70 parts; composite rubber carrier 8 parts; modified nano-silica 1 part; polylactic acid microspheres 2 parts; modified zinc fatty acid soap 2 parts; antioxidant 2 parts; white carbon black 3 parts.

[0069] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber in a mass ratio of 6:4:1; the modified zinc fatty acid soap is obtained by mixing oleic acid and stearic acid in a mass ratio of 3:1, then reacting with zinc oxide, and then modifying the obtained product with furan-maleimide derivative; and the antioxidant is antioxidant 1010.

[0070] The embodiment also provides a preparation method of the high-dispersion composite resorcinol master batch, and specifically comprises the following steps:

[0071] (1) Pre-mixing and dispersing: resorcinol is added into deionized water in proportion, stirred and mixed at 70 DEG C for 20 min, and polylactic acid microspheres are added and ultrasonically dispersed for 20 min to form a pre-mixing solution, and the pre-mixing solution is subjected to spray drying to obtain a pre-mixing material;

[0072] (2) Subsection banburying: the remaining raw materials are added into a banburying machine in proportion, and the banburying temperature is controlled in subsections, the banburying temperature is 60 DEG C in the first subsection, the mixing time is 10 min, the temperature is increased to 90 DEG C in the second subsection, the mixing time is 10 min, the temperature is decreased to 70 DEG C in the third subsection after the pre-mixing material is added, and the mixing time is 10 min, so that the glue material is obtained;

[0073] (3) Extruding and granulating: the glue material is extruded by a double-screw extruder in seven subsections, and the temperatures are 25-60 DEG C, 60-70 DEG C, 70-80 DEG C, 80-90 DEG C, 80-95 DEG C, 95-80 DEG C and 80-70 DEG C respectively, the granulation is carried out, and then the glue material is cooled to room temperature, so that the high-dispersion composite resorcinol master batch is obtained.

[0074] Comparative Example 1

[0075] The difference between the comparative example and the embodiment 2 is that the comparative example uses butadiene styrene rubber to replace the composite rubber.

[0076] The comparative example provides a high-dispersion composite resorcinol master batch, and specifically comprises the following components in weight parts:

[0077] Resorcinol 75 parts, butadiene styrene rubber 10 parts, KH-550 modified nano silicon dioxide 3 parts, polylactic acid microspheres 2 parts, modified zinc fatty acid soap 2 parts, antioxidant 1 part and white carbon black 2 parts.

[0078] The modified zinc fatty acid soap is obtained by mixing oleic acid and stearic acid in a mass ratio of 2:1, then reacting with zinc oxide, and then blending and modifying the obtained product by furan-maleimide derivative; the antioxidant is antioxidant 1010.

[0079] The comparative example also provides a preparation method of the high-dispersion composite resorcinol master batch, and specifically comprises the following steps:

[0080] (1) Pre-mixing and dispersing: resorcinol is added into deionized water in proportion, stirred and mixed at 70 DEG C for 20 min, and polylactic acid microspheres are added and ultrasonically dispersed for 20 min to form a pre-mixing solution, and the pre-mixing solution is subjected to spray drying to obtain a pre-mixing material;

[0081] (2) Sectional mixing: the remaining raw materials are added to the mixing machine in proportion, the mixing temperature is controlled in sections, the first section is 60℃, the mixing time is 10min, the second section is heated to 90℃, the mixing is 10min, the third section is added to the premix after cooling to 70℃, the mixing is 10min, and the rubber compound is obtained;

[0082] (3) Extrusion granulation: the rubber compound is extruded by a seven-section temperature control extruder, the temperatures are 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃, and 80-70℃, respectively, and then cooled to room temperature after cutting, to obtain high dispersion type composite resorcinol pellets.

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 2 is that the formula of this comparative example does not add polylactic acid microspheres.

[0085] This comparative example provides a high dispersion type composite resorcinol pellet, which specifically includes the following components by weight:

[0086] Resorcinol 75 parts; composite rubber carrier 10 parts; KH-550 modified nano silicon dioxide 3 parts; modified zinc soap of fatty acid 2 parts; antioxidant 1 part; white carbon black 2 parts.

[0087] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber in a mass ratio of 6:4:1; the modified zinc soap of fatty acid is obtained by mixing oleic acid and stearic acid in a mass ratio of 2:1 and then reacting with zinc oxide, and then blending modification with furan-maleimide derivative; the antioxidant is antioxidant 1010.

[0088] This comparative example also provides a preparation method of a high dispersion type composite resorcinol pellet, which specifically includes the following steps:

[0089] (1) Premix dispersion: resorcinol is added to deionized water in proportion and stirred and mixed at 70℃ for 20min to form a premix, and the premix is dried by spray drying to obtain a premix;

[0090] (2) Sectional mixing: the remaining raw materials are added to the mixing machine in proportion, the mixing temperature is controlled in sections, the first section is 60℃, the mixing time is 10min, the second section is heated to 90℃, the mixing is 10min, the third section is added to the premix after cooling to 70℃, the mixing is 10min, and the rubber compound is obtained;

[0091] (3) Extrusion granulation: the rubber material is extruded by a seven-section temperature control extruder, the temperature is 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃, 80-70℃ respectively, and then cooled to room temperature after granulation to obtain high dispersion type composite resorcinol granules.

[0092] Comparative Example 3

[0093] The difference between the present comparative example and Example 2 is that the zinc fatty acid soap in the present comparative example is not modified by blending furan-maleimide derivative.

[0094] The present comparative example provides a high dispersion type composite resorcinol granule, which specifically comprises the following components by weight:

[0095] Resorcinol 75 parts; composite rubber carrier 10 parts; KH-550 modified nano silicon dioxide 3 parts; polylactic acid microspheres 2 parts; zinc fatty acid soap 2 parts; antioxidant 1 part; white carbon black 2 parts.

[0096] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber and ethylene-propylene-diene rubber in a mass ratio of 6:4:1; the zinc fatty acid soap is prepared by mixing oleic acid and stearic acid in a mass ratio of 2:1 and then reacting with zinc oxide; and the antioxidant is antioxidant 1010.

[0097] The present comparative example also provides a preparation method of a high dispersion type composite resorcinol granule, which specifically comprises the following steps:

[0098] (1) Pre-mixing and dispersing: resorcinol is added to deionized water in proportion, stirred and mixed at 70℃ for 20min, and polylactic acid microspheres are ultrasonically dispersed for 20min to form a pre-mixing solution, and the pre-mixing solution is subjected to spray drying to obtain a pre-mixing material;

[0099] (2) Sectional mixing: the remaining raw materials are added to a mixing mill in proportion, and the mixing temperature is controlled in sections, the first section is 60℃, the mixing time is 10min, the second section is heated to 90℃, the mixing time is 10min, and the third section is cooled to 70℃ after adding the pre-mixing material, and the mixing time is 10min to obtain a rubber material;

[0100] (3) Extrusion granulation: the rubber material is extruded by a seven-section temperature control extruder, the temperature is 25-60℃, 60-70℃, 70-80℃, 80-90℃, 80-95℃, 95-80℃, 80-70℃ respectively, and then cooled to room temperature after granulation to obtain high dispersion type composite resorcinol granules.

[0101] Comparative Example 4

[0102] The difference between the present comparative example and Example 2 is that in the preparation method of the present comparative example, the premix is added into the internal mixer together with the remaining materials, and the premix is not added in the third stage.

[0103] The present comparative example provides a high-dispersion composite resorcinol masterbatch, which specifically comprises the following components by weight:

[0104] Resorcinol 75 parts; composite rubber carrier 10 parts; KH-550 modified nano-silica 3 parts; polylactic acid microspheres 2 parts; modified zinc fatty acid soap 2 parts; antioxidant 1 part; white carbon black 2 parts.

[0105] The composite rubber carrier is composed of liquid reclaimed rubber, styrene-butadiene rubber, and ethylene-propylene-diene rubber at a mass ratio of 6:4:1; the modified zinc fatty acid soap is obtained by reacting zinc oxide with a mixture of oleic acid and stearic acid at a mass ratio of 2:1, and then blending and modifying the obtained product with furan-maleimide derivatives; the antioxidant is antioxidant 1010.

[0106] The present comparative example also provides a preparation method of a high-dispersion composite resorcinol masterbatch, which specifically comprises the following steps:

[0107] (1) Premix dispersion: resorcinol is added into deionized water in proportion, stirred and mixed at 70°C for 20 min, polylactic acid microspheres are ultrasonically dispersed for 20 min to form a premix, and the premix is subjected to spray drying to obtain a premix;

[0108] (2) Stepwise internal mixing: the premix and the remaining raw materials are added into an internal mixer in proportion, and the internal mixing temperature is controlled in stages, the first stage is 60°C, the mixing time is 10 min, the second stage is heated to 90°C, the mixing time is 10 min, and the third stage is cooled to 70°C, the mixing time is 10 min, to obtain a rubber compound;

[0109] (3) Extrusion and granulation: the rubber compound is extruded by a seven-stage temperature control double-screw extruder at temperatures of 25-60°C, 60-70°C, 70-80°C, 80-90°C, 80-95°C, 95-80°C, and 80-70°C, respectively, and then cooled to room temperature after being cut into particles to obtain a high-dispersion composite resorcinol masterbatch.

[0110] Test Example

[0111] The composite resorcinol masterbatches prepared using the formulations and methods of Examples 2-5 and Comparative Examples 1-4 are detected for their masterbatch dispersibility, high-temperature dispersion rate, volatile loss rate, and storage stability, and the results are shown in Table 1, and the detection standards are as follows:

[0112] 1. Dispersion: observe the cross-sectional structure of the masterbatch, and the rating standards are uniform without aggregation, local aggregation, and obvious caking;

[0113] 2. High temperature fugacity: the masterbatch was placed in an oven at 150 °C for 1 hour, and the percentage of mass loss was measured;

[0114] 3. Volatilization loss rate: the masterbatch was dried at 105 °C for 24 hours, and the percentage of mass loss was calculated;

[0115] 4. Storage stability: the masterbatch was stored at 25 °C and 60% humidity for 30 days, and the caking rate of the masterbatch was measured.

[0116] Table 1

[0117]

[0118] As can be seen from Table 1, the high dispersion type composite resorcinol masterbatch prepared using the technical scheme of the present application all exhibit excellent comprehensive performance. Resorcinol is uniformly dispersed in the masterbatch without aggregation, the high temperature fugacity and volatilization loss rate are significantly lower than those of the traditional process, and the caking rate of the masterbatch during storage is less than 3%.

[0119] In Comparative Example 1, after replacing the composite carrier with a single styrene-butadiene rubber, the dispersion of the masterbatch appeared to be partially aggregated, the high temperature fugacity and volatilization loss rate were significantly increased, and the caking rate was also significantly improved. Due to the lack of the high fluidity of liquid rubber and the flexible non-polar segment of ethylene-propylene-diene rubber, the compatibility of the carrier and resorcinol is reduced, the phase separation is caused by the polarity difference during mixing, and the rigid carrier structure exacerbates the migration and escape of resorcinol.

[0120] In Comparative Example 2, the masterbatch without adding polylactic acid microspheres has a significantly improved caking rate and volatilization loss rate during storage. The absence of polylactic acid microspheres causes resorcinol to lose physical adsorption and high-temperature slow-release carrier, the local concentration gradient is too large during mixing, the active ingredient is released rapidly and absorbs moisture to caking, and the escape path is not effectively blocked.

[0121] In Comparative Example 3, the high temperature fugacity and volatilization loss rate of the zinc soap of fatty acid without modification by furan-maleimide derivative are significantly worse than those of Example 2. The absence of dynamic crosslinking network makes resorcinol unable to be effectively coated at processing temperature, and the free migration exacerbates the volatilization loss, and the uncured crosslinking network cannot inhibit the migration of the active ingredient during storage.

[0122] In Comparative Example 4, after adding the premix and the remaining raw materials into the internal mixer at one time, the dispersion of the masterbatch appears to be partially aggregated, the fugacity and the caking rate are increased. The absence of the staged mixing process causes resorcinol to be released concentratedly at high temperature, the carrier structure is not fully solidified, part of the ingredients volatilize due to premature exposure to high temperature environment, and the risk of moisture absorption and caking is exacerbated due to the incomplete dispersion of resorcinol.

[0123] The raw materials and equipment used in the present application are conventional raw materials and equipment in the art unless otherwise specified; the methods used in the present application are conventional methods in the art unless otherwise specified. The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent transformation of the above embodiment based on the technical essence of the present application still falls within the protection scope of the technical solution of the present application.

Claims

1. A method for preparing a highly dispersed resorcinol-based composite particle, characterized by, The composition comprises the following components by weight: resorcinol 70-85 parts, composite rubber carrier 8-15 parts, KH-550 modified nano-silica 0.5-5 parts, polylactic acid microspheres 1-3 parts, modified zinc fatty acid soap 1-3 parts, antioxidant 0-2 parts, and white carbon black 0-3 parts. The composite rubber carrier is composed of liquid rubber, styrene-butadiene rubber, and ethylene-propylene-diene rubber in a mass ratio of 6:4:

1. The modified zinc fatty acid soap is prepared by mixing C8-C22 unsaturated fatty acid and saturated fatty acid in a mass ratio of 2:1-3:1, then reacting with a zinc compound, and then blending and modifying the obtained product with a reversible crosslinking modifier. The method comprises the following steps: (1) resorcinol is added to deionized water and stirred and mixed, polylactic acid microspheres are added, and then ultrasonic dispersion is performed to form a premix, and the premix is subjected to spray drying to obtain a premix; (2) the remaining raw materials are added to a banbury mixer in proportion, and the banbury temperature is controlled in stages, i.e., low-temperature mixing in the first stage, temperature rising mixing in the second stage, and temperature dropping mixing in the third stage after adding the premix, to obtain a rubber compound; (3) the rubber compound is extruded through a double-screw extruder in seven stages with temperature control, and then cut into particles and cooled to room temperature to obtain high-dispersion composite resorcinol pellets.

2. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, The liquid rubber is one or more of liquid reclaimed rubber, liquid natural rubber, liquid styrene-butadiene rubber, liquid polyisoprene rubber, or liquid cis-butadiene rubber.

3. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, The modified nano-silica is modified by silane coupling agent KH-550 and has a particle size of 10-50 nm.

4. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, The polylactic acid microspheres have a porosity of 30-50% and a particle size of 50-200 μm.

5. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, The unsaturated fatty acid is one or more of oleic acid or palmitoleic acid; and the saturated fatty acid is one or more of stearic acid or lauric acid.

6. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, The zinc compound is one or more of zinc oxide or zinc hydroxide; and the reversible crosslinking modifier is furfuryl amine grafted zinc ricinoleate.

7. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, In step (1), the stirring and mixing temperature is 60-80℃, and the stirring time is 20-30 min; and the ultrasonic dispersion time is 15-25 min.

8. The method for preparing a highly dispersed composite resorcinol masterbatch according to claim 1, characterized in that, In step (2), the banbury temperature is 60-70℃ in the first stage, the mixing time is 5-10 min, the temperature is raised to 70-90℃ in the second stage, the mixing time is 8-10 min, and the temperature is dropped to 50-70℃ after adding the premix in the third stage, and the mixing time is 10-15 min.

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